Updated on 2024/06/25

写真a

 
TODA Kenji
 
Organization
Academic Assembly Institute of Science and Technology SEISAN DESIGN KOUGAKU KEIRETU Professor
Graduate School of Science and Technology Advanced Materials Science and Technology Professor
Faculty of Engineering Department of Engineering Professor
Title
Professor
▶ display Profile on researchmap
External link

Degree

  • 博士(学術) ( 1995.3   新潟大学 )

Research History (researchmap)

  • Niigata University   Institute for Research Promotion   Research Professor

    2016.10

      More details

  • SUNGKYUNKWAN UNIVERSITY

    2016.6

      More details

  • N-ルミネセンス株式会社   取締役

    2011.6

      More details

  • Tokyo Institute of Technology   Materials and Structures Laboratory

    2008.4 - 2009.3

      More details

  • Niigata University   Faculty of Engineering Department of Chemistry and Chemical Engineering   Associate Professor

    2007.4

      More details

  • Niigata University   Graduate School of Science and Technology Advanced Materials Science and Technology   Associate Professor

    2007.4

      More details

  • Tokyo Institute of Technology   Materials and Structures Laboratory

    2001.12 - 2002.3

      More details

  • Niigata University   Graduate School of Science and Technology   Associate Professor (as old post name)

    2000.1 - 2007.3

      More details

  • Niigata University   Faculty of Engineering   Associate Professor (as old post name)

    1998.4 - 2000.9

      More details

  • Niigata University   Faculty of Engineering   Assistant

    1997.4 - 1998.3

      More details

  • 日本学術振興会(大阪大学工学部)   日本学術振興会研究員(リサーチ・アソシエイト)

    1996.11 - 1997.3

      More details

  • ニッポン高度紙工業株式会社   研究員

    1988.4 - 1992.3

      More details

▶ display all

Research History

  • Niigata University   Institute of Science and Technology, Academic Assembly   Professor

    2024.6

  • Niigata University   Advanced Materials Science and Technology, Graduate School of Science and Technology   Professor

    2024.6

  • Niigata University   Department of Engineering, Faculty of Engineering   Professor

    2024.6

  • Niigata University   Institute for Research Promotion   Research Professor

    2016.10 - 2024.5

  • Niigata University   Graduate School of Science and Technology Advanced Materials Science and Technology   Associate Professor

    2007.4 - 2024.5

  • Niigata University   Faculty of Engineering Department of Chemistry and Chemical Engineering   Associate Professor

    2007.4 - 2024.5

  • Niigata University   Graduate School of Science and Technology   Associate Professor (as old post name)

    2000.1 - 2007.3

  • Niigata University   Faculty of Engineering   Associate Professor (as old post name)

    1998.4 - 2000.9

  • Niigata University   Faculty of Engineering   Research Assistant

    1997.4 - 1998.3

▶ display all

Education

  • Niigata University   Graduate School, Division of Science and Technology   物質科学専攻

    1992.4 - 1995.3

      More details

    Country: Japan

    researchmap

  • Nagaoka University of Technology   Graduate School, Division of Engineering   材料開発工学専攻

    1986.4 - 1988.3

      More details

    Country: Japan

    researchmap

Professional Memberships

▶ display all

Committee Memberships

  • 照明学会   発光型/非発光型ディスプレイ合同研究会 現地世話人  

    2014.1   

      More details

    Committee type:Academic society

    researchmap

  • 日本セラミックス協会   電子材料部会役員  

    2008.4   

      More details

    Committee type:Academic society

    researchmap

  • 日本セラミックス協会   第18回シンポジウムにて「フォトセラミックス」セッションオーガナイザー  

    2007.9   

      More details

    Committee type:Academic society

    researchmap

  • 日本セラミックス協会   東北北海道支部幹事  

    2007.4   

      More details

    Committee type:Academic society

    researchmap

  • 光触媒研究会   世話人  

    2007.4   

      More details

    Committee type:Academic society

    researchmap

  • 日本電子材料技術協会   理事および「表示デバイス素子材料研究部会」主査  

    2007.4   

      More details

    Committee type:Academic society

    researchmap

  • 日本化学会   2005 International Chemical Congress of Pacific Basin Societies(環太平洋国際化学会議Pacifichem2005)Solid State Chemistryセッションオーガナイザー  

    2005.12   

      More details

    Committee type:Academic society

    researchmap

  • 日本希土類学会   Rare Earths '04(希土類国際会議) Spectroscopy and Optical Materials オーガナイザー  

    2004.10   

      More details

    Committee type:Academic society

    researchmap

  • 日本化学会   関東支部職域会員代表  

    2002.4 - 2004.3   

      More details

    Committee type:Academic society

    researchmap

▶ display all

 

Papers

  • Blue-yellow multicolor phosphor, Eu2+-activated Li3NaSiO4: Excellent thermal stability and quenching mechanism Reviewed

    Masato Iwaki, Shota Kumagai, Shoma Konishi, Atsuya Koizumi, Takuya Hasegawa, Kazuyoshi Uematsu, Atsushi Itadani, Kenji Toda, Mineo Sato

    Journal of Alloys and Compounds   2018.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Novel and Incredibly Facile Low Temperature Solid State Route to Nano-Sized Eu3+ Activated BaTiO3 Phosphors Reviewed

    Usama Bin Humayoun, Sintayehu Nibret Tiruneh, Yung-Hyun Song, Takaki Masaki, Kenji Toda, Dae-Ho Yoon

    Science of Advanced Materials   10 ( 9 )   1225 - 1229   2018.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Room-Temperature Solid State Contact Reaction Synthesis of Rare Earth Free RbVO3 Phosphor and Their Photoluminescence Properties Reviewed

    Tadashi Ishigaki, Puttaswamy Madhusudan, Shinnosuke Kamei, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    ECS Journal of Solid State Science and Technology   7 ( 6 )   R88 - R93   2018.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELECTROCHEMICAL SOC INC  

    Rare earth free RbVO3 ceramic materials were prepared by facile solid-solid contact reaction between Rb2CO3 and V2O5 powders at room temperature within few minutes. Synchrotron X-ray power diffraction analysis and energy dispersive X-ray spectroscopy study showed that the resultant nanoparticles are crystalline with almost 100% purity. Further, the as-prepared sample showed emission spectrum intensity at 530 nm implying that RbVO3 ceramic materials can be used for white LED application. In addition, when 0.01 M aqueous NH4OH was added to the mixture of Rb2CO3 and V2O5, the emission intensity of the product was about twice higher than that of the product obtained from the reaction in moist air. The luminescence internal quantum efficiency (QE) of as-prepared RbVO3 phosphor is about 35% as estimated by a direct method. The present room-temperature fabrication method has great potential in large-scale fabrication of phosphor materials as well as other composite functional materials due to significantly reduced reaction time and energy. (C) 2018 The Electrochemical Society.

    DOI: 10.1149/2.0201806jss

    Web of Science

    researchmap

  • Luminescence enhancement of LiSrPO4:Eu2+ phosphor by Mg2+ ion addition Reviewed

    Kamei Shinnosuke, Tomoki Hatsumori, Takuya Hasegawa, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    Materials Research Innovations   2018.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of High-Efficiency Red-Emission Ca14Zn6Al9.97Mn0.03O35 Phosphors with Particle Control Reviewed

    Man Gyu Hur, Seung Hee Choi, Seok Bin Kwon, Takaki Masaki, Kenji Toda, Dae Ho Yoon

    Ceramics International   44   15868 - 15872   2018.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of Na<inf>2</inf>FePO<inf>4</inf>F using polytetrafluoroethylene Reviewed

    Atsushi Tsu-Ura, Hirotaka Torii, Takuya Hasegawa, Dai Murayama, Sun Woog Kim, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    Journal of the Ceramic Society of Japan   126 ( 5 )   336 - 340   2018.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    © 2018 The Ceramic Society of Japan. All rights reserved. Polytetrafluoroethylene (PTFE), composed of fluorine and carbon atoms, has a potential to produce carbon-coated fluorides in the calcination of inorganic compounds. We synthesized high voltage cathode material for Na ion secondary battery, Na2FePO4F, using PTFE as the carbon-coating and fluorine source. The Na2FePO4F carbon-coated by a thermal decomposition of PTFE showed high discharge capacity (64.4 mAh g11) at the first cycle of galvanostatic cycling by the improvement of conductivity.

    DOI: 10.2109/jcersj2.17230

    Scopus

    researchmap

  • Paradigm Change for Solid State Reactions: Synthesis of Lithium Orthophosphate Li3PO4 Nanoparticles by a Water Assisted Solid State Reaction (WASSR) Method Reviewed

    Sun Woog Kim, Kenji Toda, Takuya Hasegawa, Mizuki Watanabe, Tatsuro Kaneko, Ayano Toda, Atsushi Itadani, Mineo Sato, Kazuyoshi Uematsu, Tadashi Ishigaki, Junko Koide, Masako Toda, Yoshiaki Kudo, Takaki Masaki, Dae Ho Yoon

    Science of Advanced Materials   10 ( 4 )   592 - 596   2018.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER SCIENTIFIC PUBLISHERS  

    Lithium orthophosphate Li3PO4 nanoparticles were synthesized through a water assisted solid state reaction (WASSR) method. The nanoparticles obtained in this study adopt a stable orthorhombic structure (beta-type), which is a low temperature phase, in a single phase with high crystallinity. The Li3PO4 nanoparticles have a granular particle morphology and the particle size is less than 50 nm.

    DOI: 10.1166/sam.2018.2844

    Web of Science

    researchmap

  • Structure of triaquatris(1,1,1-trifluoro-4-oxo-pentan-2-olato)cerium(III) as a possible fluorescent compound Reviewed

    Atsuya Koizumi, Takuya Hasegawa, Atsushi Itadani, Kenji Toda, Taoyun Zhu, Mineo Sato

    Acta Crystallographica Section E: Crystallographic Communications   74   229 - 232   2018.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    © 2018 International Union of Crystallography. Luminescence due to the d-f transition of Ce3+ is quite rare in metal-organic complexes where concentrate quenching frequently occurs. One of the possible ways to avoid this is to design an architecture with elongated metal-metal distances. In the structure of the title complex, triaquatris(1,1,1-trifluoro-4-oxopentan-2-olato-2O,O0)cerium(III), [Ce(C5H4F3O2)3(H2O)3], the CeIII complex is linked to neighbouring ones by hydrogen bonding. Within the complex, the CeIII atom is coordinated by nine O atoms from three 1,1,1-trifluoro-4-oxopentan-2-olate (tfa) anions as bidentate ligands and three water molecules as monodentate ligands. Thus, the coordination number of CeIII atom is nine in a monocapped square-antiprismatic polyhedron. The F atoms of all three independent CF3 groups in tfa are disordered over two positions with occupancy ratios of about 0.8:0.2. The intermolecular hydrogen bonds between the ligands involve tfa-water interactions along the [110] and [110] directions, generating an overall two-dimensional layered network structure. The presence of the F atoms in the tfa anion is responsible for an increased intermolecular metal-metal distance compared to that in the analogous acetylacetonate (acac) derivatives. Fluorescence from Ce3+ is, however, not observed.

    DOI: 10.1107/S2056989018001135

    Scopus

    researchmap

  • Luminescence property of silicate phosphor, Ba9Sc2Si6O24:Ce, synthesized by melt quenching technique Reviewed

    Kenji Toda, Atsushi Tsu-Ura, Minenori Katsu, Shin-Nosuke Kamei, Tadashi Ishigaki, Kazuyoshi Uematsu, Mineo Sato

    Key Engineering Materials   766   186 - 190   2018

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:Trans Tech Publications Ltd  

    Well-grown Ba9Sc2Si6O24:Ce3+ phosphors were synthesized by a novel melt quenching synthesis method. Sintered phosphor balls with excellent luminescent characteristics were obtained. This method is useful tool for rapid screening of phosphor materials.

    DOI: 10.4028/www.scientific.net/KEM.766.186

    Scopus

    researchmap

  • Synthesis of nano-sized materials using novel water assisted solid state reaction method Reviewed

    Kenji Toda, Tatsuro Kaneko, Takuya Hasegawa, Mizuki Watanabe, Yusuke Abe, Takeshi Kuroi, Mineo Sato, Kazuyoshi Uematsu, Sun Woog Kim, Yoshiaki Kudo, Takaki Masaki, Dae Ho Yoon

    Key Engineering Materials   777 KEM   163 - 167   2018

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)  

    © 2018 Trans Tech Publications, Switzerland. We report synthesis of nano-sized oxide materials using a novel water assisted solid state reaction (WASSR) method. This novel soft chemical synthesis method is very simple and can synthesize nanoparticle materials just by storing or mixing raw materials added a small amount (typically 10wt%) of water in a reactor at low temperature below 373 K. Combinations of raw materials have a significant influence on the reaction rate.

    DOI: 10.4028/www.scientific.net/KEM.777.163

    Scopus

    researchmap

  • Bluish-White Luminescence in Rare-Earth-Free Vanadate Garnet Phosphors: Structural Characterization of LiCa3MV3O12 (M = Zn and Mg) Reviewed

    Takuya Hasegawa, Yusuke Abe, Atsuya Koizumi, Tadaharu Ueda, Kenji Toda, Mineo Sato

    Inorganic Chemistry   57 ( 2 )   857 - 866   2017.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Nanophosphors synthesized by the water assisted solid state reaction (WASSR) method: Luminescence properties and reaction mechanism of the WASSR method Reviewed

    Sun Woog Kim, Takuya Hasegawa, Mizuki Watanabe, Masaru Muto, Toshiya Terashima, Yusuke Abe, Tatsuro Kaneko, Ayano Toda, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato, Emiko Kawakami, Junko Koide, Masako Toda, Yoshiaki Kudo, Takaki Masaki, Dae Ho Yoon

    Applied Spectroscopy Reviews   52 ( 10 )   1 - 18   2017.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Yellow MgV2O6 center dot 2H(2)O nanophosphor synthesized by a water-assisted solid-state reaction (WASSR) method at low temperature below 80 degrees C Reviewed

    Sun Woog Kim, Yusuke Abe, Mizuki Watanabe, Takuya Hasegawa, Masaru Muto, Ayano Toda, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato, Emiko Kawakami, Junko Koide, Masako Toda, Yoshiaki Kudo, Toshiyuki Masui, Takaki Masaki, Dae Ho Yoon

    DYES AND PIGMENTS   145   339 - 344   2017.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Magnesium metavanadate dihydrate (MgV2O6.2H(2)O) was synthesized as a nanophosphor by a water assisted solid-state reaction (WASSR) method, and its crystal structure and luminescence properties were investigated in detail. MgV2O6.2H(2)O has an orthorhombic structure with space group Pnma. In the crystal structure, the MgO6 octahedra and VO4 tetrahedra formed a layered structure in the direction of the b axis, and the VO4 tetrahedra formed a chain structure along the a axis. The nanophosphor showed broad and strong optical absorption in the near-ultraviolet region and exhibited a broad yellow emission peak at 563 nm. (C) 2017 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.dyepig.2017.06.024

    Web of Science

    researchmap

  • Synthesis and optical properties of P 5+ co-doped Ba 3 SiO 5 :Eu 2+ orange persistent phosphor Reviewed

    Seung Hee Choi, Seok Bin Kwon, Usama Bin Humayoun, Won Kyu Park, Kenji Toda, Masato Kakihana, Takaki Masaki, Woo Seok Yang, Young Hyun Song, Dae Ho Yoon

    Dyes and Pigments   148   460 - 464   2017.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier B.V.  

    researchmap

  • Stabilization of novel high temperature phase yellow-emitting σ-type (Ba<inf>1-: X - Y</inf>Eu<inf>x</inf>Mg<inf>y</inf>)<inf>2</inf>P<inf>2</inf>O<inf>7</inf> phosphors using a melt synthesis technique Reviewed

    H. Nakagawa, S. W. Kim, T. Hasegawa, S. Hasegawa, T. Ishigaki, K. Uematsu, K. Toda, H. Takaba, M. Sato

    Inorganic Chemistry Frontiers   4 ( 9 )   1562 - 1567   2017.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    © 2017 the Partner Organisations. Novel Eu2+-activated phosphate phosphors based on high-temperature phase σ-Ba2P2O7, which is an unstable phase at room temperature, were synthesized for the first time by a melt synthesis technique using an arc-imaging furnace. By doping Mg2+ into the host lattice, Eu2+-activated σ-Ba2P2O7 phosphors were successfully obtained in a single phase form of a hexagonal structure and the emission intensity was also effectively enhanced. The relative emission peak intensity of the σ-(Ba0.67Eu0.03Mg0.30)2P2O7 phosphor was 315% of that for the σ-(Ba0.97Eu0.03)2P2O7 phosphor. The emission color tunable from green emission with a peak at 516 nm to yellow emission with a peak at 551 nm can be achieved by controlling the Mg2+ content in the σ-(Ba0.97-yEu0.03Mgy)2P2O7 phosphors.

    DOI: 10.1039/c7qi00359e

    Scopus

    researchmap

  • Unusual, broad red emission of novel Ce3+ -activated Sr3Sc4O9 phosphors under visible-light excitation Reviewed

    Takuya Hasegawa, Sun Woog Kim, Tadaharu Ueda, Tadashi Ishigaki, Kazuyoshi Uematsu, Hiromitsu Takaba, Kenji Toda, Mineo Sato

    JOURNAL OF MATERIALS CHEMISTRY C   5 ( 36 )   9472 - 9478   2017.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    Most conventional white light emitting diodes (white-LEDs) that are widely used as a new lighting system in next generation lights with Y3Al5O12: Ce3+ (YAG: Ce3+)-based phosphors have a low colour rendering index (CRI) because the YAG: Ce3+ phosphor shows a weak emission intensity in the red spectral region. Therefore, discovering a red-emitting phosphor with a high-efficiency is quite important to enhance the CRI of white-LEDs. In this study, we successfully discovered a novel, red-emitting Ce3+-activated Sr3Sc4O9 phosphor that can be excited by blue-light irradiation at 425 nm. A crystal structure of the host material was first determined by Rietveld refinement, which indicated that it should be isostructural with Ba(3)Ln(4)O(9) (Ln = Sc, Y and Dy-Lu). As the Ce3+ content increased, the X-ray diffraction patterns shifted to a lower angle, which suggested that the Ce3+ ion could substitute Sc in the Sr3Sc4O9 host. Under UV and blue-light excitation, the Ce3+-activated Sr3Sc4O9 phosphor exhibited a broad emission band with a maximum peak at 620 nm, and its full width half maximum (FWHM) was 180 nm (4530 cm(-1)). The highest emission intensity was obtained for Sr-3(Sc0.997Ce0.003)(4)O-9, and the internal quantum efficiency of this phosphor under excitation at 425 nm was 53%. To the best of our knowledge, the emission band of the Ce3+-activated Sr3Sc4O9 phosphor is the longest wavelength for a reported Ce3+-activated oxide phosphor.

    DOI: 10.1039/c7tc03203j

    Web of Science

    researchmap

  • Exquisite morphology, highly emissive yellow Sr1.44Ba0.46SiO4:0.1Eu(2+) phosphor synthesized by a liquid phase precursor process Reviewed

    Usama Bin Humayoun, Young Hyun Song, Seok Bin Kwon, Kakihana Masato, Kenji Toda, Yasushi Sato, Takaki Masaki, Dae-Ho Yoon

    DYES AND PIGMENTS   142   147 - 152   2017.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Yellow phosphors are the major components of contemporary solid-state lights. YAG:Ce3+ is a widely adopted yellow phosphor component; however, it too has limitations. Here, we report the synthesis and application of a very highly efficient yellow-emitting orthosilicate phosphor. Yellow-emitting Sr1.44Ba0.46SiO4:0.1Eu(2+) was synthesized by an unconventional cellulose template liquid phase precursor process (CTLPP). The naturally abundant and nonhazardous cellulose template facilitates efficient synthesis at lower temperatures. The synthesized phosphor was indexed to alpha-Sr2SiO4 phase and exhibited broad excitation and broad emission with a peak at 545 nm, very high intensity, almost 130% of commercial YAG upon excitation at 450 nm. The morphology of the phosphors was also nearly spherical, which also enables their use in WLEDs. Use of non-stoichiometric Si precursors (i.e. Sr1.44Ba0.46SixO4:0.1Eu(2+), x = 0.95, 1.0 and 1.05) in the process resulted in remarkable effects on the morphology (size and surface) and luminescent characteristics and exceptional quantum efficiencies of the phosphors. (C) 2017 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.dyepig.2017.03.029

    Web of Science

    researchmap

  • Improvement of luminescence properties of rubidium vanadate, RbVO3, phosphors by erbium doping in the crystal lattice Reviewed

    S. W. Kim, T. Hasegawa, M. Muto, A. Toda, T. Kaneko, K. Sugimoto, K. Uematsu, T. Ishigaki, K. Toda, M. Sato, J. Koide, M. Toda, Y. Kudo

    NEW JOURNAL OF CHEMISTRY   41 ( 12 )   4788 - 4792   2017.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    Greenish-white emitting Rb1-xErxVO3 (0 &lt;= x &lt;= 0.10) phosphors were synthesized by a conventional solid state reaction method. The thermal quenching effect of the RbVO3 phosphors was effectively improved by Er3+ doping into the RbVO3 lattice. Consequently, the emission peak intensity of the phosphors was successfully enhanced by Er3+ doping, and the internal quantum efficiency of Rb0.99Er0.01VO3 under excitation at 360 nm was 80%.

    DOI: 10.1039/c6nj03823a

    Web of Science

    researchmap

  • On the possibility of polystyrene-derived carbon coating for NASICON-type Na3V2(PO4)(3) composites as cathode materials for sodium-ion batteries Reviewed

    Dai Okada, Takumi Fugane, Yuka Matsumoto, Takuya Hasegawa, Atsushi Itadani, Kazuyoshi Uematsu, Kenji Toda, Hideki Hashimoto, Jun Takada, Mineo Sato

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   125 ( 4 )   322 - 325   2017.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    We here prepared polystyrene-derived carbon-coated Na3V2(PO4)(3) composite (NVP/C) cathode materials via a solid-phase reaction using a mixture of NVP precursor and polystyrene (as the carbon source), followed by calcination at high temperatures. Using this method, we were able to obtain active NVP materials with relatively high purity while allowing a uniform surface coating with carbon layers about 3-4 nm thick. This structure significantly prevented NVP particle growth even after calcination at high temperatures. The NVP/C material calcined at 700 degrees C exhibited the best charge-discharge performance among the samples studied. (C) 2017 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.16266

    Web of Science

    researchmap

  • Discovery of novel inorganic Mn5+-doped sky-blue pigments based on Ca6BaP4O17: Crystal structure, optical and color properties, and color durability Reviewed

    Sun Woog Kim, Go Eun Sim, Ji Young Ock, Jeong Hun Son, Takuya Hasegawa, Kenji Toda, Dong Sik Bae

    DYES AND PIGMENTS   139   344 - 348   2017.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Novel inorganic sky-blue pigments, Ca6Ba(P1-xMnx)4O(17) (0 &lt;= x &lt;= 0.13) were synthesized in a single phase form by a conventional solid-state reaction method and their color properties were investigated in the detail. The pigments exhibited strong optical absorption in the UV and the yellow-red light regions due to the cT transition in MnO4 tetrahedra and the DMSO-d(6) transitions of Mn5+, which is the origin of the sky-blue color. The optimization of the composition resulted in the attainment of the highest sky-blue hue for the Ca6Ba(P0.99Mn0.01)4O(17), where the L*, a*, b*, C, and H values are 75.47, -11.67, -10.29, 15:6, and 221.4 degrees, respectively. These pigments showed a low chemical stability of color for acid/alkali solution, whereas the pigments showed an excellent color durability for heat and light. Although they are required to improve the chemical stability of color, the present pigment could be an attractive candidate as a novel environment friendly inorganic sky-blue pigment.(C) 2016 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.dyepig.2016.12.038

    Web of Science

    researchmap

  • Development of a novel nontoxic vivid violet inorganic pigment - Mn3+-doped LaAlGe2O7 Reviewed

    Sun Woog Kim, Yu Saito, Takuya Hasegawa, Kenji Toda, Kazuyoshi Uematsu, Mineo Sato

    DYES AND PIGMENTS   136   243 - 247   2017.1

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Novel nontoxic LaAl1-xMnxGe2O7 (0.01 &lt;= x &lt;= 0.20) violet pigments were synthesized through a conventional solid-state reaction. The crystal structures, optical properties, and color properties of these pigments were investigated. The LaAl1-xMnxGe2O7 (0.01 &lt;= x &lt;= 0.20) pigments prepared in the present study show excellent potential as environmentally friendly inorganic violet pigments. These pigments exhibit a strong optical absorption in the yellow-red light region due to the Mn3+ d-d transitions, which is the origin of the violet color. Among the obtained LaAl1-xMnxGe2O7 (0.01 &lt;= x &lt;= 0.20) pigments, LaAl0.90Mn0.10Ge2O7 showed the most vivid violet color and the L*, a*, and b* values are 50.8, 18.0, and -29.7, respectively, values greater than those of a commercial cobalt violet pigment (Co-3(PO4)(2); L* = 46, a* = 33, b* = 32). Because the LaAl0.90Mn0.10Ge2O7 pigment is composed of nontoxic elements, this pigment can be an effective alternative to currently used commercial violet pigments. (C) 2016 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.dyepig.2016.08.038

    Web of Science

    researchmap

  • Environmentally friendly Rb3V5O14 fluorescent red pigment Reviewed

    Sun Woog Kim, Takuya Hasegawa, Mizuki Watanabe, Kazuma Sugimoto, Yu Saito, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    DYES AND PIGMENTS   136   219 - 223   2017.1

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Rb3V5O14, which was successfully synthesized by a water assisted solid state reaction (WASSR) method, is a fluorescent red pigment that is environmentally friendly. The Rb3V5O14 fluorescent pigment showed a strong optical absorption in the green light region due to the energy transfer from O2- 2p orbital to V5+ 3d orbital of VO5 polyhedra and band-gap energy of Rb3V5O14 was 2.02 eV. The fluorescent pigment presented a broad red emission peaked at 625 nm due to the T-3(2) -&gt; (1)A(1) and T-3(1) -&gt; (1)A(1) transitions of the [VO4](3-) group. The Rb3V5O14 fluorescent pigment showed a bright-vivid red body color, and the L*, a*, and b* values were 47.4, +45.9, and +34.4, respectively. (C) 2016 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.dyepig.2016.08.040

    Web of Science

    researchmap

  • A new lanthanum(III) complex containing acetylacetone and 1 H -imidazole Reviewed

    Atsuya Koizumi, Takuya Hasegawa, Atsushi Itadani, Kenji Toda, Taoyun Zhu, Mineo Sato

    Acta Crystallographica Section E: Crystallographic Communications   73   1739 - 1742   2017

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    © Koizumi et al. 2017. In the title complex, diaqua(1H-imidazole-κN 3)(nitrato-κ 2 O,O′)bis(4-oxopent-2-en-2-olato-κ 2 O,O′)lanthanum(III), [La(C 5 H 7 O 2) 2 (NO 3)(C 3 H 4 N 2)(H 2 O) 2 ], the La atom is coordinated by eight O atoms of two acetylacetonate (acac) anions acting as bidentate ligands, two water molecule as monodentate ligands, one nitrate anions as a bidentate ligand and one N atom of an imidazolate (ImH) molecule as a monodentate ligand. Thus, the coordination number of the La atom is nine in a monocapped square antiprismatic polyhedron. There are three types of intermolecular hydrogen bonds between ligands, the first involving nitrate-water O⋯H - O interactions running along the [001] direction, the second involving acac-water O⋯H - O interactions along the [010] direction and the third involving an Im-nitrate N - H⋯O interaction along the [100] direction (five interactions of this type). Thus, an overall one-dimensional network structure is generated. The molecular plane of an ImH molecule is almost parallel to that of a nitrate ligand, making an angle of only 6.04(12)°. Interestingly, the ImH plane is nearly perpendicular to the planes of two neighbouring acac ligands.

    DOI: 10.1107/S205698901701461X

    Scopus

    researchmap

  • Development of water assisted solid state reaction for the ceramic materials Reviewed

    Kenji Toda, Sun Woog Kim, Takuya Hasegawa, Mizuki Watanabe, Tatsuro Kaneko, Ayano Toda, Ryota Yamanashi, Shota Kumagai, Masaru Muto, Atsushi Itadani, Mineo Sato, Kazuyoshi Uematsu, Tadashi Ishigaki, Junko Koide, Masako Toda, Emiko Kawakami, Yoshiaki Kudo, Takaki Masaki, Dae Ho Yoon

    Key Engineering Materials   751 KEM   353 - 357   2017

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)  

    © 2017 Trans Tech Publications, Switzerland. We report a novel soft chemical synthesis method, water assisted solid state reaction (WASSR) method. This method is very simple and can synthesize many ceramic materials just by storing or mixing raw materials added a small amount of water in a reactor at low temperature below 373 K. For example, well-crystalline SrMoO4 was obtained using the WASSR method.

    DOI: 10.4028/www.scientific.net/KEM.751.353

    Scopus

    researchmap

  • Determination of the crystal structure and photoluminescence properties of NaEu1-xGdx(MoO4)(2) phosphor synthesized by a water-assisted low-temperature synthesis technique Reviewed

    Takuya Hasegawa, Sun Woog Kim, Yusuke Abe, Masaru Muto, Mizuki Watanabe, Tatsuro Kaneko, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Mineo Sato, Junko Koide, Masako Toda, Yoshiaki Kudo

    RSC ADVANCES   7 ( 40 )   25089 - 25094   2017

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    A single-phase red-emitting NaEu(MoO4)(2) phosphor with nanosized particles was synthesized using a water-assisted solid state reaction (WASSR) method, a new low-temperature synthesis method developed by our group. NaEu(MoO4)(2) exhibits a monoclinic structure with a space group C2/c (no. 15), which is composed of a Na/EuO8 dodecahedron with the site occupancy of Na/Eu = 1 : 1 and an MoO4 tetrahedron. To enhance the emission intensity of the NaEu(MoO4)(2) phosphor, Gd3+ was doped into the Eu3+ sites and NaEu1-xGdx(MoO4)(2) (0 &lt; x &lt;= 0.50) samples were synthesized using the WASSR method. The emission intensity of the phosphors was successfully enhanced by increasing the Gd3+ content in the samples with 0 &lt;= x &lt;= 0.30, but was reduced with x &gt; 0.30. This indicates that the optimum composition of the phosphor for achieving a high emission intensity that is similar to 3.8 times higher than that of the NaEu(MoO4)(2) (x = 0) phosphor is NaEu0.70Gd0.30(MoO4)(2). These phosphors exhibit a granular particle morphology with the particle size of the phosphor being similar to 200 nm.

    DOI: 10.1039/c7ra01832k

    Web of Science

    researchmap

  • Luminescence of phosphor balls prepared using melt quenching synthesis method Reviewed

    Takuya Hasegawa, Kenji Toda, Tadashi Ishigaki, Shinnosuke Kamei, Sun Woog Kim, Kazuyoshi Uematsu, Mineo Sato, Masahiro Yoshimura

    Materials Science Forum   883   17 - 21   2017

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)  

    © 2017 Trans Tech Publications, Switzerland. Well-grown M3MgSi2O8 (M = Ca, Sr and Ba):Eu2+ phosphors were synthesized by novel melt quenching synthesis method. The luminescence property of the Sr3MgSi2O8:Eu2+ phosphor synthesized by the melt synthesis method is comparable to those of the sample synthesized by a conventional solid state reaction. Sintered phosphor balls with excellent luminescent characteristics were obtained.

    DOI: 10.4028/www.scientific.net/MSF.883.17

    Scopus

    researchmap

  • Synthesis of Li2SiO3 using novel water-assisted solid state reaction method Reviewed

    Mizuki Watanabe, Jun Inoi, Sun Woog Kim, Tatsuro Kaneko, Ayano Toda, Mineo Sato, Kazuyoshi Uematsu, Kenji Toda, Junko Koide, Masako Toda, Emiko Kawakami, Yoshiaki Kudo, Takaki Masaki, Dae Ho Yoon

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   125 ( 6 )   472 - 475   2017

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Single phase of orthorhombic Li2SiO3 was synthesized via a novel soft-chemical synthesis method, water assisted solid state reaction method at 343-353K for 60 min. The crystal structure of the samples was characterized by X-ray diffraction (XRD) analysis. The scanning electron microscope (SEM) observation revealed that the estimated size of the particles is 50-200 nm. The XRD patterns and SEM images were compared to those of samples by a conventional solid state method at 1173K for 4 h. (C) 2017 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.16325

    Web of Science

    researchmap

  • Improvement of Emission Intensity for Near-infrared-emitting Ca14Zn6Al10O35:Mn4+ Phosphor by Oxygen-pressure Method Reviewed

    Takuya Hasegawa, Sun Woog Kim, Takeshi Abe, Shota Kumagai, Ryota Yamanashi, Kohei Seki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    CHEMISTRY LETTERS   45 ( 9 )   1096 - 1098   2016.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CHEMICAL SOC JAPAN  

    We employed an oxygen-pressure method as a novel approach to improve the emission intensity of a Ca14Zn6Al10O35:Mn4+ phosphor. With this new approach, the Ca14Zn6Al10O35:Mn4+ phosphor exhibited near-infrared emission under excitation at 450 rim, and the emission intensity of a Caw Zn-6(Al0.97Mn0.03)(10)O-35 phosphor was effectively enhanced by approximately 143% compared with that of a Ca14Zn6(Al0.97Mn0.03)(10)O-35 phosphor synthesized by a conventional solid-state reaction method in air.

    DOI: 10.1246/cl.160498

    Web of Science

    researchmap

  • Suppress of Concentration Quenching by Site Engineering Concept Reviewed

    Y. Imanari, T. Hasegawa, M. Watanabe, K. Toda, T. Ishigaki, S. Kamei, S. W. Kim, K. Uematsu, M. Sato

    Applied Mechanics and Materials   851   132 - 137   2016.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis and photoluminescence properties of oxynitride phosphors M0.98Si2O2N2: Eu-0.02(2+) (M=Ba, Sr, Ca) using the cellulose assisted liquid phase precursor process Reviewed

    Yelim Song, Younghyun Song, Kenji Toda, Takaki Masaki, Daeho Yoon

    CERAMICS INTERNATIONAL   42 ( 8 )   9667 - 9672   2016.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Oxynitride phosphors M0.98Si2O2N2: Eu-0.02(2+)(M=Ba, Sr, Ca) for white LEDs were synthesized at 1300,1400, and 1500 degrees C by using the partially cellulose assisted liquid phase precursor (PLPP) process and compared with solid state reaction (SSR) process. MSi2O2N2 (M=Ba, Sr, Ca) crystal structure was obtained from M0.98Si2O2N2: Eu-0.02(2+) phosphor fired at 1400 degrees C using the PLPP process. However these phosphors were not synthesized through the SSR process at same temperature. M0.98Si2O2N2: Eu-0.02(2+)(M=Ba, Sr, Ca) phosphors from PLPP produced a blue color emission at 487 nm (380 nm excitation), a green color emission at 528 nm (374 nm excitation), and a yellow color emission at 538 nm (371 nm excitation). M0.98Si2O2N2: Eu-0.02(2+) phosphors from PLPP had higher luminescence and crystallinity compared with those obtained from the SSR process. The prepared phosphors were analyzed by X-ray diffraction (XRD), photoluminescence (PL) and field-emission scanning electron microscopy (FE-SEM). (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

    DOI: 10.1016/j.ceramint.2016.03.055

    Web of Science

    researchmap

  • Abnormal improvement in emission of lanthanum oxysulfide phosphor La2O2S:Tb3+ synthesized by a novel method, thermal decomposition in eutectic molten salt Reviewed

    Sun Woog Kim, Takuya Hasegawa, Takeshi Abe, Hiroko Nakagawa, Shota Hasegawa, Kohei Seki, Kenji Toda, Kazuyoshi Uematsu, Tadashi Ishigaki, Mineo Sato

    CERAMICS INTERNATIONAL   42 ( 8 )   10389 - 10392   2016.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    The lanthanum oxysulfide phosphor La2O2S:Tb3+ is generally synthesized by the direct sulfidation of La2O3 using H2S or CS2 gas. However, these gases are known to be highly toxic to humans. In this paper, a new synthesis method that uses 0.6U(2)SO(4)-0.4Na(2)SO(4) as the flux is proposed for obtaining La2O2S:Tb3+ phosphor, without the need for H2S or CS2 gas. The proposed method consists of two steps: 1) oxidation to obtain La2O2SO4 and 2) reduction to reduce La2O2SO4 to La2O2S. Using this novel method, (La1-xTbx)(2)O2S (0.01 &lt;x &lt; 0.13) were successfully synthesized in a single-phase form. The synthesized phosphors exhibited extraordinary luminescence behavior. Further, despite their low Tb3+ ion content, the phosphors showed high emission intensities. The relative emission intensity of (La0.95Tb0.05)(2)O2S (lambda(ex) = 270 nm) was 132% that of the commercial green-emitting phosphor (La0.52Ce0.31Tb0.17)PO4 (lambda(ex) = 285 nm), which shows the highest excitation absorption. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

    DOI: 10.1016/j.ceramint.2016.03.176

    Web of Science

    researchmap

  • Physical studies on the enhancement of photoluminescence properties for blue BaAl2Si2O8 : Eu2+ phosphors via LPP method with addition of silicate concentrations Reviewed

    Bong Sung Kim, Min Ji Lee, Takesi Abe, Takaki Masaki, Young-Hyun Song, Kenji Toda, Dae-Ho Yoon

    JOURNAL OF CERAMIC PROCESSING RESEARCH   17 ( 4 )   286 - 289   2016.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:KOREAN ASSOC CRYSTAL GROWTH, INC  

    BaAl2Si2O8: Eu2+ + xSiO(2) (x = 0, 1, 2 and 3) has been synthesized with phosphors via novel liquid phase precursor (LPP) method. The best crystalline BaAl2Si2O8 : Eu2+ phosphor could not be synthesized as the calcination temperature is inadequate fully to crystalize the phosphor leading to the crystal and amorphous. Albeit, the firing temperature is insufficient so as to form the fine crystal, the added excess SiO2 could act as an additive for the crystallization of the phosphor. As a function of SiO2, the size of the crystal has been augmented and formed fine crystals with the concentration of added SiO2. Moreover, the added excess SiO2 makes SiOC : Eu2+ phosphor as a deep blue illumination at 440 nm. Photoluminescence intensity of the phosphors is increased continuously by the addition of SiO2 heretofore x = 3. In the present investigation, an attempt has been made to synthesize and observe carefully for photoluminescence properties with regard to the crystalline structure, optical property and surface morphology.

    Web of Science

    researchmap

  • Synthesis of high intensity green emitting (Ba,Sr)SiO4:Eu2+ phosphors through cellulose assisted liquid phase precursor process Reviewed

    Usama Bin Humayoun, Young-Hyun Song, Minji Lee, Kakihana Masato, Hiroshi Abe, Kenji Toda, Yasushi Sato, Takaki Masaki, Dae-Ho Yoon

    OPTICAL MATERIALS   51   110 - 114   2016.1

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Green emitting phosphor (Ba1-xSr1-x)SiO4:2xEu(2+), x = 0.03, 0.05, 0.1, and 0.15 were synthesized through a Liquid Phase Precursor Process (LPP). Liquid phase precursor method is reported to result in phosphors with markedly increased emission intensities compared to other synthesis methods. Here microcrystalline cellulose (MCC) and hydroxypropyl cellulose (HPC) templates were studied to achieve high efficiency green phosphors. The phase formation was investigated by XRD analysis which showed the conformation of the Ba2SiO4 (JCPDS card number 761631) phase. The obtained samples exhibited broad excitation spectra with maximum at 430 nm and a green emission centered around 520 nm. An optimized dopant concentration was selected and the effect of two different types of cellulose, i.e. MCC and HPC templates on the emission properties was considered. It was found that the samples synthesized using HPC and fired at 1050 degrees C under a reducing atmosphere, showed a high intensity of almost 2 times that of the MCC sample. Further experiments were conducted by varying viscosity, particle weight, and molecular weight of the HPC template. It was found that the green emission from the (Ba,Sr)SiO4:Eu2+ increased with the increase in viscosity and molecular weight of the template. (C) 2015 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.optmat.2015.11.036

    Web of Science

    researchmap

  • Rare-earth-free white emitting Ba2TiP2O9 phosphor: revealing its crystal structure and photoluminescence properties Reviewed

    Takuya Hasegawa, Sun Woog Kim, Shinnosuke Kamei, Tadashi Ishigaki, Kazuyoshi Uematsu, Koutoku Ohmi, Kenji Toda, Mineo Sato

    DALTON TRANSACTIONS   45 ( 28 )   11554 - 11559   2016

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    A high intensity bluish-white emitting Ba2TiP2O9 phosphor was synthesized by a conventional solid-state reaction method and the precise crystal structure was investigated for the first time by Rietveld refinement analysis. Ba2TiP2O9 has a monoclinic crystal structure with a space group C2/c (no. 15), which is built out of PO4 tetrahedra and TiO5 pyramidal polyhedra connected to form a chain structure along the c-axis. The emission of Ba2TiP2O9 is due to a charge transfer transition between Ti4+-O2- in the pyramidal TiO5. The obtained Ba2TiP2O9 was excited efficiently by UV and VUV and displayed a bright bluish-white luminescence.

    DOI: 10.1039/c6dt01715k

    Web of Science

    researchmap

  • Improved synthesis of SrLiAl3N4:Eu2+ phosphor using complex nitride raw material Reviewed

    S. W. Kim, T. Hasegawa, S. Hasegawa, R. Yamanashi, H. Nakagawa, K. Toda, T. Ishigaki, K. Uematsu, M. Sato

    RSC ADVANCES   6 ( 66 )   61906 - 61908   2016

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    Narrow band deep-red emission SrLiAl3N4:Eu2+ phosphor was synthesized using complex nitride Sr3Al2N4 and Li3AlN2 as raw materials. The SrLiAl3N4:Eu2+ phosphor has the oxoplumbate type triclinic structure as the main phase. The phosphor exhibited deep-red emission peaking at 654 nm under excitation at 450 nm and showed an excellent thermal stability on the thermal quenching effect.

    DOI: 10.1039/c6ra14107b

    Web of Science

    researchmap

  • Novel yellowish white-emitting Eu<sup>2+</sup>-activated phosphate phosphor based on Rb<inf>2</inf>Ba<inf>3</inf>P<inf>4</inf>O<inf>14</inf> Reviewed

    Kazuma Sugimoto, Takuya Hasegawa, Sunwoog Kim, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    Journal of Ceramic Processing Research   17 ( 5 )   401 - 404   2016

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    © 2016, Hanyang University. All rights reserved. Eu2+-doped Rb2Ba3P4O14 phosphors were synthesized in a single phase form by a conventional solid state reaction method and their optical properties were characterized. These phosphors showed broad optical absorption bands that can cover the UV and near-UV region, and exhibited a narrow deep-blue emission and broad reddish-yellow emission with peaks at 423 nm and 550 nm, respectively. The highest reddish-yellow emission intensity was obtained for Rb2(Ba0.99Eu0.01)3P4O14.

    Scopus

    researchmap

  • Novel soft chemical synthesis methods of ceramic materials Reviewed

    Kenji Toda, Sun Woog Kim, Takuya Hasegawa, Mizuki Watanabe, Tatsuro Kaneko, Ayano Toda, Atsushi Itadani, Mineo Sato, Kazuyoshi Uematsu, Tadashi Ishigaki, Junko Koide, Masako Toda, Yoshiaki Kudo, Takaki Masaki, Dae Ho Yoon

    Key Engineering Materials   690   268 - 271   2016

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)  

    © 2016 Trans Tech Publications, Switzerland. We report novel soft chemical synthesis method, solid hydratethermal reaction (SHR) method as a new soft chemistry. This method is very simple and can synthesize the ceramic materials just by storing the mixture of raw materials added a small amount of water in a reactor at low temperature below 373 K. For example, Nano-size YVO4 (under 100 nm in diameter) was obtained using the SHR method.

    DOI: 10.4028/www.scientific.net/KEM.690.268

    Scopus

    researchmap

  • Electrochemical Properties of LiFePO4 Cathode Materials Coated with Newly Developed Carbon Black Reviewed

    Dai Okada, Takuma Sugiki, Kazuyoshi Uematsu, Atsushi Itadani, Kenji Toda, Mineo Sato, Togo Yamaguchi, Nozomi Arimitsu, Shogo Nishikawa

    ELECTROCHEMISTRY   83 ( 10 )   858 - 860   2015.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELECTROCHEMICAL SOC JAPAN  

    A new type of carbon black CB1 was developed, by Asahi Carbon Co., Ltd., for usage of a lithium-ion battery (LIB). Compared with commercially available acetylene black, CB1 in which the network structure of carbon is developed has a relatively larger specific surface area. Therefore, CB1 dispersed in LiFePO4 precursors by planetary ball milling inhibited LiFePO4 primary particles' growth during calcination process. Charge/discharge performance was improved by coexistence of CB1 with polystyrene (PS) carbon layers deposited on LiFePO4 particle surfaces, compared to the performance for the LiFePO4 sample covered with carbon layers derived from only PS. (C) The Electrochemical Society of Japan, All rights reserved.

    DOI: 10.5796/electrochemistry.83.858

    Web of Science

    researchmap

  • Improvement of High Rate Performances for Ti-Doped Li3V2(PO4)(3) Cathode Materials Reviewed

    Dai Okada, Fumiya Nakano, Kazuyoshi Uematsu, Hirokazu Okawa, Atsushi Itadani, Kenji Toda, Mineo Sato

    ELECTROCHEMISTRY   83 ( 10 )   828 - 830   2015.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELECTROCHEMICAL SOC JAPAN  

    Ti-doped lithium vanadium(III) phosphate cathode materials, Li3-2x(V1-xTix)(2)(PO4)(3), were prepared by a solid state reaction. The Ti-doped samples exhibited that the gamma-phase is stabilized at room temperature by substituting Ti for V sites at more than x = 0.10. The discharge capacity of the doped samples at a 60C rate was found to be much higher than that for the non doped sample. This improved performance found for the doped cathodes was attributed to the increase in ionic conductivity given by the transition of alpha- to gamma-phase via Ti substitution. (C) The Electrochemical Society of Japan, All rights reserved.

    DOI: 10.5796/electrochemistry.83.828

    Web of Science

    researchmap

  • Novel green-emitting Ho3+-doped scandate phosphors Reviewed

    Kazuma Sugimoto, Sun Woog Kim, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Mineo Sato

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   123 ( 1441 )   880 - 883   2015.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Blue-light excitable, green-light emitting Ba-3(Sc1-xHox)(4)O-9 phosphors were successfully synthesized in the single-phase form by a melt synthesis method for the first time. These phosphors show sharp green light emission under blue light (455 nm) excitation. The principal green light emission peak observed at 555 nm corresponds to the transition from F-5(4) and S-5(2) to the I-5(8) energy level of Ho3+. (C) 2015 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.123.880

    Web of Science

    researchmap

  • Synthesis of YVO4 Nano Particles by Novel Room Temperature Synthesis Method Reviewed

    Tatsuro Kaneko, Sun Woog Kim, Ayano Toda, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Mineo Sato, Junko Koide, Masako Toda, Yoshiaki Kudo, Takaki Masaki, Dea Ho Yoon

    SCIENCE OF ADVANCED MATERIALS   7 ( 8 )   1502 - 1505   2015.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER SCIENTIFIC PUBLISHERS  

    Yttrium orthovanadate, YVO4 was prepared using a novel water assisted room temperature solid state reaction method, consisting of simply mixing of Y2O3 and V2O5 at room temperature with the addition of a small amount of water. Nano-scale spherical particles of YVO4 approximately 10-100 nm in diameter were obtained.

    DOI: 10.1166/sam.2015.2364

    Web of Science

    researchmap

  • Synthesis and Luminescent Properties of Novel Ca3Y3Ge2BO13:Ln(3+) (Ln(3+) = Tb3+ and Eu3+) phosphors Reviewed

    Takuya Hasegawa, Natsuki Sato, Sun Woog Kim, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   123 ( 1438 )   507 - 511   2015.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Novel Ln(3+)-doped (Ln(3+) = Tb3+ and Eu3+) and Eu3+, Bi3+ co-doped Ca3Y3Ge2BO13 phosphors were synthesized by a conventional solid-state reaction method. Tb3+- and Eu3+-doped phosphors showed strong narrow green and red emission due to 4f intra-shell transitions of the Tb3+ or Eu3+ ions under the excitation at 254 nm. Bi3+ co-doped Ca3Y3Ge2BO13:Eu3+ phosphor has a new broad strong excitation band appeared at around 302 nm due to S-1(0)-&gt; P-3(1) transition of Bi3+, and presents red emission owing to 4f-4f transition of Eu3+ under excitation at 302 nm. (C)2015 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.123.507

    Web of Science

    researchmap

  • Viscosity analysis of alkali metal carbonate molten salts at high temperature Reviewed

    Sun Woog Kim, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   123 ( 1437 )   355 - 358   2015.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    The viscosities of unary, binary, and ternary eutectic alkali metal carbonate molten salts were measured for the first time by a rotation method using a high-temperature rheometer system and the reliability of the viscosity values was evaluated. The viscosity values obtained in this study are similar to that reported by Sato's research group, which is considered to have the highest reliability among the studies reported till date. The standard errors in the viscosity values at each temperature are less than +/- 5%. (C) 2015 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.123.355

    Web of Science

    researchmap

  • Luminescence and Morphology Control of Phosphor Materials Synthesized by Melt Synthesis Method Reviewed

    K. Toda, T. Ishigaki, S. Kamei, S. W. Kim, K. Uematsu, M. Sato, M. Yoshimura

    Applied Mechanics and Materials   752-753   221 - 224   2015.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of new green-emitting KBa1-xScSi3O9:Eu-x(2+) phosphors for white LEDs Reviewed

    Takeshi Abe, Sun Woog Kim, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    OPTICAL MATERIALS   38   57 - 60   2014.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    New green-emitting KBa1-xScSi3O9:Eu-x(2+) phosphors for white LEDs were synthesized by a conventional solid-state reaction method. The obtained KBa1_xScSi3O9:Eu-x(2+) phosphors show the strong broad optical absorption band from UV to blue light region and exhibit broad green emission with a peak at 521 nm under excitation at 405 nm due to the allowed 4f(6)5d(1)-4f(7) transition of Eu2+. Optimization of Eu2+ concentration resulted in the highest green emission peak intensity was obtained at the composition of KBa0.94ScSi3O9:Eu-0.06(2+), and the relative emission intensity of this phosphor was 32% of that of a commercial YAG:Ce3+ phosphor. (C) 2014 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.optmat.2014.10.003

    Web of Science

    researchmap

  • Synthesis and Photoluminescence Properties of HEu1-xGdx(MoO4)(2) Nanophosphor Invited Reviewed

    Mizuki Watanabe, Kazuyoshi Uematsu, Sun Woog Kim, Kenji Toda, Mineo Sato

    IEICE TRANSACTIONS ON ELECTRONICS   E97C ( 11 )   1063 - 1067   2014.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    New HEu1-xGdx(MoO4)(2) nanophosphors were synthesized by a simple one-step ion-exchange method. These nanophosphors have rod-like particle morphology with 0.5-15 mu m in length and outer diameters in the range of 50-500 nm. By optimization of the composition, the highest emission intensity was obtained for the samples with x = 0.50 for both KEu1-xGdx(MoO4)(2) and HEu1-xGdx(MoO4)(2).

    DOI: 10.1587/transele.E97.C.1063

    Web of Science

    researchmap

  • Site engineering concept of Ce3+-activated novel orange-red emission oxide phosphors Reviewed

    Yukari Kawano, Sun Woog Kim, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Hiromitsu Takaba, Mineo Sato

    OPTICAL MATERIALS EXPRESS   4 ( 9 )   1770 - 1774   2014.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:OPTICAL SOC AMER  

    Novel Sr-6(Y1-xCex)(2)Al4O15 (0.005 &lt;= x &lt;= 0.20) phosphors were synthesized in a single phase form by a conventional solid-state reaction method. These phosphors can be achieved the emission color tunable from blue to orange-red by controlling the Ce3+ doping site in the Sr6Y2Al4O15 lattice and exhibit orange-red emission centered on 600 nm by blue light irradiation as the Ce3+ concentration was increased. To the best of our knowledge, this is the first report of Ce3+ doping oxide phosphor exhibiting orange-red emission centered on 600 nm under blue light excitation. (C) 2014 Optical Society of America

    DOI: 10.1364/OME.4.001770

    Web of Science

    researchmap

  • Influence of amorphous and crystalline type precursor intermediates on the morphology and luminescence properties of green emitting beta-Ca2SiO4:Eu2+ phosphor synthesized using a liquid phase precursor method Reviewed

    Deok Su Jo, Jihae Kim, Karupannan Senthil, Hoo-Jeong Lee, Ho Kyoon Chung, Masato Kakihana, Toda Kenji, Takaki Masaki, Dae Ho Yoon

    JOURNAL OF ALLOYS AND COMPOUNDS   608   311 - 317   2014.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    Influence of precursor intermediates (PI) on the synthesis of high efficient green emitting beta-Ca2SiO4:Eu2+ (beta-C2S:Eu) phosphors were demonstrated by a novel liquid-phase-precursor (LPP) method utilizing (a) CaCl2-EuCl3, (b) Ca(NO3)(2)-EuCl3, (c) CaCl2-Eu(NO3)(3), and (d) Ca(NO3)(2)-Eu(NO3)(3) combinations as precursors. The crystallinity and morphology of the PI analyzed using X-ray diffraction and high-resolution transmission electron microscopy measurements showed both the amorphous and crystalline type precursor intermediates (API and CPI) depending upon the metal-source materials. The final morphology and luminescence properties of beta-C2S:Eu phosphors were found to be strongly influenced by the crystallinity (amorphous and crystalline) and morphology of the PIs. The APIs have led to regular-shaped homogeneous phosphor particles with higher luminescence when compared with the CPIs. (C) 2014 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jallcom.2014.04.133

    Web of Science

    researchmap

  • Liquid Phase Precursor driven approach for the synthesis of Ca-Sr-Ba orthosilicate phosphors for white LED applications Reviewed

    Neetu Tyagi, Deok Su Jo, Takeshi Abe, Kenji Toda, Takaki Masaki, Dae Ho Yoon

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   122 ( 1429 )   806 - 809   2014.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Compositions of (CaSrBa) orthosilicate phosphors were prepared by Liquid Phase Precursor method. The structural phase determinations were done systematically by powder X ray diffraction and Transmission electron microscopy. The PL emission was observed under 450 and 375 nm excitation and green-red and pure green emission was observed for the 4f(6)5d -&gt; 4f(7) transition of Eu2+ ion. The luminescence nature of the samples is determined to vary with crystal field effect on the Eu2+ ion and has been studied with the change in the binary Ca-Sr, Ba-Sr and ternary Ca-Sr-Ba compositions. (C) 2014 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.122.806

    Web of Science

    researchmap

  • Novel Deep Red Emitting Phosphors Ca14Zn6M10:Mn4+ (M = Al3+ and Ga3+) Reviewed

    Kohei Seki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    CHEMISTRY LETTERS   43 ( 8 )   1213 - 1215   2014.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CHEMICAL SOC JAPAN  

    This study investigated the luminescence properties of novel deep red phosphors Ca14Zn6M10O35:Mn4+ (M = Al3+ and Ga3+). These phosphors efficiently excited using a blue LED light. It exhibited a deep red emission around 713 nm. The luminescence intensities of CZA:Mn-0.03 and CZG:Mn-0.03 excited at 450 nm were, respectively, about 2.2 and 2.7 times higher than that of YAG:Ce3+ (P46). These phosphors also show little temperature quenching, but more than that shown by YAG:Ce3+ at 423 K. These results show that the deep red phosphor Ca14Zn6M10O35:Mn4+ (M = Al3+ and Ga3+) is a beneficial phosphor for use in indoor plant cultivation.

    DOI: 10.1246/cl.140227

    Web of Science

    researchmap

  • Synthesis of Eu2+-activated Rb-Ba-Sc-Si-O glass phosphors using melt synthesis technique Reviewed

    Sun Woog Kim, Takuya Hasegawa, Michiyo Inoue, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   122 ( 1426 )   452 - 463   2014.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Eu2+-activated Rb-Ba-Sc-Si-O glass phosphor was synthesized by a melt synthesis technique using arc-imaging furnace and their photoluminescence properties were characterized. In addition, the obtained glass phosphors annealed in a flow of 5%H-2-95% Ar gas to enhance the luminescent efficiency. The emission spectra of the Eu2+-activated glass phosphors presents yellow emission band centered at 537nm due to the 4f(6)5d(1) -&gt; 4f(7) transition of Eu2+, and the emission intensity was effectively enhanced by the annealing treatment. (C) 2014 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.122.452

    Web of Science

    researchmap

  • Novel Reddish Yellow-emitting Ce3+-Doped Ba3Sc4O9 Phosphors for Blue-light-based White LEDs Reviewed

    Takuya Hasegawa, Sun Woog Kim, Tadashi Ishigaki, Kazuyoshi Uematsu, Hiromitsu Takaba, Kenji Toda, Mineo Sato

    CHEMISTRY LETTERS   43 ( 6 )   828 - 830   2014.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CHEMICAL SOC JAPAN  

    Novel reddish yellow-emitting Ba-3(Sc1-xCex)(4)O-9 (0 &lt;= x &lt;= 0.01) phosphors were synthesized in a single-phase form by a conventional solid-state reaction method. These phosphors exhibited excellent optical absorption in the blue-light region and showed reddish yellow emission with a peak at 583 urn due to the 5d -&gt; 4f transition of Ce3+ under excitation at 437 nm. By optimizing the Ce3+ concentration, the maximum emission intensity was obtained for Ba-3(Sc0.999Ce0.001)(4)O-9.

    DOI: 10.1246/cl.140070

    Web of Science

    researchmap

  • Synthesis of FeF3 fluoride electrode material using polytetrafluoroethylene Reviewed

    Hirotaka Torii, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Mineo Sato

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   122 ( 1426 )   473 - 476   2014.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    A fluoride electrode material for lithium-ion batteries, FeF3, was synthesized by a novel solid-state reaction method using polytetrafluoroethylene (PTFE) as a fluoride source instead of HF. FeF3 was obtained as the main phase according to the XRD patterns of the samples prepared in the present study. Furthermore, the synthesized FeF3 particles were nanosize. The initial discharge and charge capacities of the FeF3 sample were 387 and 293mAh/g, respectively, in the 4.5-1.0V region. (C) 2014 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.122.473

    Web of Science

    researchmap

  • Synthesis of blue-emitting (K <inf>1-x</inf>Na <inf>x</inf>)Mg <inf>4</inf>(PO <inf>4</inf>)<inf>3</inf>:Eu <sup>2+</sup> phosphors Reviewed

    Sun Woog Kim, Takuya Hasegawa, Tadashi Ishigaki, Kazuyoshi Uematsu, Mineo Sato, Kenji Toda

    Journal of Information Display   15 ( 2 )   53 - 57   2014.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Blue-emitting (K 1-xNa x)Mg 4(PO 4)3:Eu 2+ phosphors were synthesized through a conventional solid-state reaction method, and their photoluminescence properties were characterized. These phosphors exhibited the typical emission band assigned to the transition from 4f65d1 to 4f7 of Eu2+, and the emission intensity was effectively enhanced by Na +-doping into the host lattice. The highest blue emission peak intensity was obtained for (K 0.65Na 0.35)Mg 4(PO 4)3:1 mol%Eu2+, where the relative emission peak intensity was 33% of that for the commercial blue-emitting BaMgAl 10O 17:10 mol%Eu 2+ phosphor. In addition, these phosphors have excellent thermal stability in the temperature quenching effect. © 2014 © 2014 The Korean Information Display Society.

    DOI: 10.1080/15980316.2014.907213

    Scopus

    researchmap

  • SrxAl2O4:Eu0.0152+Dy0.033+ (x=1.1-1.7) green emitting phosphors with efficient emissive properties Reviewed

    Neetu Tyagi, Deok Su Jo, Takeshi Abe, Kenji Toda, Sang-Jun Lee, Sung Gook Oh, Takaki Masaki, Dae Ho Yoon

    JOURNAL OF LUMINESCENCE   147   245 - 249   2014.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Monophasic SrAl2O4:Eu2+ Dy3+ with varying Sr2+ concentration was synthesized in monoclinic symmetry by the Liquid Phase Precursor method. The composition Sr1.7Al2O4:Eu0.0152+Dy0.033+ showed the 200% emission compared with commercial Sr0.97Al2O4:Eu-0.01(2+) Dy-0.02(3+). Time decay measurements of the doped samples were conducted for the green emission at 525 nm. All the prepared samples exhibit rapid decay and ensued phosphorescence with the longer decay times which are comparable to the commercial sample. Quantum yield product measurements results suggested that the synthesized phosphors show enhanced emissive properties over the commercial phosphor. The composition Sr1.7Al2O4:Eu0.0152+Dy0.033+ had a photoluminescence quantum yield of 31.63%, nearly 12.7% more than the commercial sample. (C) 2013 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jlumin.2013.11.018

    Web of Science

    researchmap

  • Accelerating the emission properties beyond the skidding effect of varying Sr, Eu and Dy concentration in SrAl2O4 : Eu Dy phosphors Reviewed

    N. Tyagi, D. S. Jo, K. Toda, T. Masaki, D. H. Yoon

    JOURNAL OF CERAMIC PROCESSING RESEARCH   15 ( 4 )   251 - 255   2014

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:KOREAN ASSOC CRYSTAL GROWTH, INC  

    Eu and Dy-doped strontium aluminate is a long-lasting phosphor for practical applications in displays and emergency signage. SrAl2O4 synthesized samples have been systematically investigated by PXRD, SEM and photoluminescence. The optimization of the properties has been determined in terms of varying concentrations of Sr2+ (alkali metal ion concentration) and the dopant concentrations of Eu2+ and Dy3+. A new method of synthesis requiring hydrate solutions of the metal ions and cellulose precursor called Liquid Phase Precursor method (LPP) has been adapted. The emission intensity was observed to be higher for the prepared samples compared to a commercial product prepared with a solid state reaction method.

    Web of Science

    researchmap

  • Synthesis and the luminescent properties of silicate NaAlSiO4:Eu2+ phosphor using SiO powder as a silica source Reviewed

    Takeshi Abe, Kenji Toda, Kazuyoshi Uhematsu, Mineo Sato, Tadashi Ishigaki, Kim Bong Sung, Deok Su Jo, Takaki Masaki, Dae Ho Yoon

    ELECTROCERAMICS IN JAPAN XVI   582   214 - +   2014

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    A yellow-emitting NaAlSiO4:Eu2+ phosphor was synthesized using SiO powder as a reducing agent and a silica source material. The emission intensity of the NaAlSiO4:Eu2+ phosphor synthesized using SiO powder is higher than that of a sample produced using a conventional silicate phosphor synthesis reaction using SiO2 powder. The ratio of non-reduced Eu3+ ions in the NaAlSiO4:Eu2+ phosphor synthesized using SiO powder was decreased by the reduction effect of SiO powder.

    DOI: 10.4028/www.scientific.net/KEM.582.214

    Web of Science

    researchmap

  • Title Synthesis and photoluminescence properties of Mn2+ co-doped white emitting (Sr,Sn)ZnP2O7 phosphor Reviewed

    Sun Woog Kim, Takuya Hasegawa, Hiroyuki Yumoto, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    JOURNAL OF CERAMIC PROCESSING RESEARCH   15 ( 3 )   177 - 180   2014

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:KOREAN ASSOC CRYSTAL GROWTH, INC  

    Rare earth-free white emitting (Sr,Sn)(Zn,Mn)P2O7 phosphors were synthesized in a single phase form by a conventional solid-state reaction method and photoluminescent properties were characterized. These phosphors showed three broad band in emission spectra at 340, 440, and 690 nm, and the ratio of emission intensity between blue-green light and red light changes with Mn2+ content increasing because of energy transfer from Sn2+ to Mn2+. The emission color of the phosphors varied from blue-white to orange-white with the increase in the Mn2+ content and the emission color of the (Sr0.90Sn0.10)(Zn0.97Mn0.03)P2O7 phosphor was very close to white light.

    Web of Science

    researchmap

  • A novel bluish green-emitting RbBaScSi3O9 : Eu2+ phosphor for white LEDs Reviewed

    Takeshi Abe, Sun Woog Kim, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    JOURNAL OF CERAMIC PROCESSING RESEARCH   15 ( 3 )   181 - 184   2014

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:KOREAN ASSOC CRYSTAL GROWTH, INC  

    A novel bluish green-emitting silicate phosphor, RbBaScSi3O9 : Eu2+, was synthesized by a conventional solid state reaction method. The RbBaScSi3O9 : Eu2+ phosphor can be excited by a near-UV and blue light irradiation and presents a bluish green band centered at 500 nm due to the allowed transition from 4f(6)5d(1) to 4f(7) of Eu2+. The maximum emission peak intensity was obtained at the composition of RbBaScSi3O9 : 10 mol% Eu2+, and the emission intensity was 13% compared with that of the commercial YAG phosphor.

    Web of Science

    researchmap

  • Synthesis and photoluminescence properties of HEu(MoO4)(2) nanophosphor Reviewed

    Mizuki Watanabe, Kazuyoshi Uematsu, Sun Woog Kim, Kenji Toda, Mineo Sato

    JOURNAL OF CERAMIC PROCESSING RESEARCH   15 ( 3 )   173 - 176   2014

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:KOREAN ASSOC CRYSTAL GROWTH, INC  

    The HEu(MoO4)(2) nanophosphor was synthesized for the first time by the H+-exchange of KEu(MoO4)(2). The nanophosphor obtained in the present study maintain the triclinic KEu(MoO4)(2) type structure in a single phase form with high crystallinity. The HEu(MoO4)(2) phosphor has rod-like particle morphology (length 0.5-20 mu m, diameter 50-400 nm). Both HEu(MoO4)(2) powder and solution shows red emission due to the 4f-4f transition of Eu3+.

    Web of Science

    researchmap

  • Synthesis and the luminescent properties of NaAlSiO4:Eu2+ phosphor using SiO powder as a silica source Reviewed

    Takeshi Abe, Sun Woog Kim, Tadashi Ishigaki, Kazuyoshi Uematsu, Mineo Sato, Takaki Masaki, Dae Ho Yoon, Kenji Toda

    Journal of Information Display   15 ( 1 )   31 - 35   2014

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:E-flow Taylor and Francis  

    A yellow-emitting silicate phosphor, NaAlSiO4:Eu2+, was synthesized through a new reducing technique, using SiO powder as a silica source, during the preparation process. The addition of SiO powder as a silica source significantly enhanced the Eu2+ content, which led to an increase in the photoluminescence emission intensity of the NaAlSiO4:Eu2+ phosphor. The optimization of the composition resulted in obtaining the maximum emission intensity for NaAlSiO4:7 mol% Eu2+. © 2014 The Korean Information Display Society.

    DOI: 10.1080/15980316.2014.886628

    Scopus

    researchmap

  • Synthesis of down-converting red emission Ca14Zn6Al10-xMnxO35 phosphors for use in solar cells Reviewed

    Mangyu Hur, Takaki Masaki, Kenji Toda, Dae Ho Yoon

    JOURNAL OF CERAMIC PROCESSING RESEARCH   15 ( 3 )   197 - 199   2014

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:KOREAN ASSOC CRYSTAL GROWTH, INC  

    Ca14Zn6Al10-xMnxO35 (x = 1, 3, 5 mol%, CZAMO) phosphor materials were synthesized using the liquid phase precursor (LPP) method. Nanostructrued cellulose was impregnated with metal-hydrate solution and then calcined to vaporize the cellulose. The impregnated cellulose was fired at 800 to 1200 degrees C to give the CZAMO phosphors. The particle size and crystal structure of the phosphors were analyzed by FE-SEM and XRD. Nano-sized particles with a dominant Ca14Zn6Al10O35 structure (100 nm) were obtained by firing at 800 degrees C for 1 h. The red emission wavelength of the phosphors ranged from 650 to 750 nm, peaking at 713 nm.

    Web of Science

    researchmap

  • Long phosphorescent Ca2SnO4 with minuscule rare earth dopant concentration Reviewed

    Tadashi Ishigaki, Akiko Torisaka, Kentarou Nomizu, Puttaswamy Madhusudan, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    Dalton Transactions   42 ( 14 )   4781 - 4785   2013.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Rare-earth doped Ca2SnO4 phosphors were synthesized using a conventional solid state reaction method. The red phosphorescence of Eu3+ was observed in this system with persistence time. In the as-prepared samples, the doped rare earth ions occupied both Ca and Sn sites in the host lattice. The longest phosphorescent persistence property can be achieved for the Ca2SnO4 phosphors with a 0.1% Eu dopant. Depending on the doped rare earth ions, afterglow emissions of various colors were observed. © 2013 The Royal Society of Chemistry.

    DOI: 10.1039/c3dt33079f

    Scopus

    researchmap

  • Research on new precursor for nanosheets phosphors Reviewed

    K. Tanima, M. Watanabe, Y. Imanari, S. Kamei, K. Uematsu, T. Shigaki, K. Toda, M. Sato, T. Masaki, D. H. Yoon

    Journal of Ceramic Processing Research   14 ( 1 )   s71 - s73   2013.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Luminescent properties of Eu-activated Mg-Y-Si-O-N glass and crystalline phosphors Reviewed

    S. Sato, S. Kamei, K. Uematsu, T. Ishigaki, K. Toda, M. Sato, H. Sasaoka, M. Ooka, K. Nishimura

    Journal of Ceramic Processing Research   14 ( 1 )   s77 - s79   2013.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of broadband emission phosphor Ca2KMg2(V1xPx)(3)O-12 for white light emitting diodes Reviewed

    M. Maeda, K. Uematsu, S. Kamei, T. Ishigaki, K. Toda, M. Sato

    JOURNAL OF CERAMIC PROCESSING RESEARCH   14 ( 1 )   S60 - S63   2013.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:KOREAN ASSOC CRYSTAL GROWTH, INC  

    We report the increased emission intensity of Ca2KMg2V3O12 by partially substituting the V5+ ion for the P5+ ion. The emission intensity of Ca2KMg2(V0.95P0.05)(3)O-12 was approximately 1.3 times greater than that of Ca2KMg2V3O12. The obtained phosphors were excited and emitted at 360 nm and 520 nm, respectively, and the emission obtained as a greenish white emission. The color coordinates of Ca2KMg2(V0.95P0.05)(3)O-12 were x = 0.377 and y = 0.463.

    Web of Science

    researchmap

  • Synthesis of Zn2SiO4:Mn2+ using SiOx as an oxidation inhibitor Reviewed

    T. Sakamoto, S. Kamei, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Journal of Ceramic Processing Research   14 ( 1 )   s64 - s66   2013.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Enhancement of photoluminescence properties of SrAl2Si2O8:Eu2+ by a large amount of SiO2 addition Reviewed

    B. S. Kim, Y. H. Song, D. S. Jo, T. Abe, K. Senthil, T. Masaki, K. Toda, D. H. Yoon

    JOURNAL OF CERAMIC PROCESSING RESEARCH   14 ( 1 )   S12 - S14   2013.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis and luminescence properties of rare earth doped Na3AlP3O9N oxynitridophosphate phosphor Reviewed

    S. Sato, S. Kamei, K. Uematsu, T. Ishigaki, K. Toda, M. Sato, H. Sasaoka, M. Ooka, K. Nishimura

    Journal of Ceramic Processing Research   14 ( 1 )   s74 - s76   2013.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Enhancement of the luminescence efficiency of Li2TiO3:Mn4+ red emitting phosphor for white LEDs Reviewed

    K. Seki, S. Kamei, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Journal of Ceramic Processing Research   14 ( 1 )   s67 - s70   2013.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Efficient red emission of blue-light excitable new structure type NaMgPO<inf>4</inf>:Eu<sup>2+</sup> phosphor Reviewed

    Sun Woog Kim, Takuya Hasegawa, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    ECS Solid State Letters   2 ( 12 )   R49 - R51   2013

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    A novel red-emitting olivine-type NaMgPO4:Eu2+ phosphor was synthesized for the first time by the melt synthesis technique using arc-imaging furnace. The NaMgPO4:Eu2+ phosphor can be efficiently excited by blue light irradiation and presents red emission band centered at 628 nm due to the 4f65d1 → 4f7 transition of Eu2+. The highest emission peak intensity was obtained for NaMgPO4:2.5mol%Eu2+, and the internal quantum efficiency of this phosphor at the excitation wavelength of 450 nm was 81%. Furthermore, these phosphors show an excellent thermal stability on the temperature quenching effect. © 2013 The Electrochemical Society.

    DOI: 10.1149/2.004312ssl

    Scopus

    researchmap

  • Synthesis and Photoluminescence Studies of Eu3+ Activated Borosilicate Phosphor (Gd1-xEux)(3)BSi2O10 for White Light Emitting Diodes Reviewed

    Tadashi Ishigaki, Puttaswamy Madhusudan, Michiyo Inoue, Shinnosuke Kamei, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY   2 ( 2 )   R3018 - R3020   2013

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELECTROCHEMICAL SOC INC  

    Certain silicate materials with different crystal structures show excellent luminescence properties. Furthermore, these silicate compounds have high chemical and thermal stability and considered as an excellent phosphor host materials. In this study, we report (Gd1-xEux)(3)BSi2O10 as a novel ultraviolet (UV) excited white phosphors prepared under solid state reaction and their luminescence properties at 393 nm excitation were investigated in detail. The as prepared (Gd1-xEux)(3)BSi2O10 phosphors showed red emission with UV (around 580-630 nm) and near-UV light (around 250-410 nm). The chromaticity coordinates (0.60, 0.34) of the prepared borosilicate phosphor were very close to the NTSC standard value (0.67, 0.33) and its emission intensity was almost similar to commercial red phosphor Y2O2S:0.05Eu(3+). Further, as prepared (Gd1-xEux)(3)BSi2O10 material is considered to be an efficient red-emitting phosphor for UV based light emitting diodes (LED). (C) 2012 The Electrochemical Society.

    DOI: 10.1149/2.007302jss

    Web of Science

    researchmap

  • Hydrothermal synthesis of meso/macroporous BiVO4 hierarchical particles and their photocatalytic degradation properties under visible light irradiation Reviewed

    Puttaswamy Madhusudan, Malahalli Vijaya Kumar, Tadashi Ishigaki, Kenji Toda, Kazuyoshi Uematsu, Mineo Sato

    Environmental Science and Pollution Research   20 ( 9 )   6638 - 6645   2013

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    An ordered hierarchical meso/macroporous monoclinic bismuth vanadate (BiVO4) particle was fabricated for the first time by a simple two-step melamine template hydrothermal method followed by calcination. The physiochemical parameters of as-prepared porous materials were characterized by means of X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, Raman, Barrett-Emmett-Teller, and UV-vis techniques. The nitrogen adsorption-desorption measurement and pore size distribution curve suggest that meso/macropores exist in these hierarchical microarchitectures. Further, it is found that melamine plays a significant role in the formation of porous BiVO4 particles, and when a known amount of melamine was added, the surface area and pore size of such porous BiVO4 particles were increased. The photocatalytic activities of the as-prepared hierarchical BiVO4 samples were measured for the photodegradation of Congo red aqueous dye solution under visible light irradiation. Surprisingly, the porous BiVO4 particles showed outstanding photocatalytic activities than polycrystalline BiVO4 sample. The possible enhancement of such catalytic performance has also been further discussed. © 2013 Springer-Verlag Berlin Heidelberg.

    DOI: 10.1007/s11356-013-1694-x

    Scopus

    PubMed

    researchmap

  • Enhancement of photoluminescence properties of CaAl2Si2O8:Eu2+ by SiO2 addition Reviewed

    B. S. Kim, Y. H. Song, D. S. Jo, T. Abe, K. Senthil, T. Masaki, K. Toda, D. H. Yoon

    MATERIALS RESEARCH BULLETIN   47 ( 10 )   3015 - 3019   2012.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    SiO2 added phosphors, CaAl2Si2O8:Eu2+ + xSiO(2) (x = 0, 1, 2, 3, 4, 5, 6 and 13 mol) were synthesized by a novel liquid phase precursor (LPP) method. The photoluminescence properties of phosphor added by 5 mol of SiO2 showed 110% enhancement in the emission intensity compared to the CaAl2Si2O8:Eu2+ phosphor. A broad emission and excitation wavelength was observed approximately from 400 nm to 600 nm centered at 430 nm and from 280 nm to 400 nm centered at 365 nm, respectively. Photoluminescence intensity of the phosphors increased continuously by SiO2 addition up to x = 5 mol and then it decreased with further addition of SiO2. The observed photoluminescence properties of the phosphors were discussed related to their crystalline structure and morphology. (C) 2012 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.materresbull.2012.04.109

    Web of Science

    researchmap

  • Redetermination of the low-temperature polymorph of Li 2MnSiO4 from single-crystal X-ray data Reviewed

    Mineo Sato, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Hirokazu Okawa

    Acta Crystallographica Section E: Structure Reports Online   68 ( 9 )   i68 - i69   2012.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Crystals of dilithium manganese(II) silicate were grown under high-temperature hydro-thermal conditions in the system LiOH - MnO2 - SiO2. The title compound crystallizes in the ΒII-Li 3PO4 structure type. The coordination polyhedra of all cations are slightly distorted tetra-hedra (m symmetry for MnO4 and SiO4), which are linked by corner-sharing to each other. The vertices of the tetra-hedra point to the same direction perpendicular to the distorted hexa-gonal close-packed (hcp) array of O atoms within which half of the tetra-hedral voids are occupied by cations. In comparison with the previous refinement from powder X-ray data [Dominko et al. (2006). Electrochem. Commun. 8, 217-222], the present reinvestigation from single-crystal X-ray data allows a more precise determination of the distribution of the Li+ and Mn2+ cations, giving a perfectly site-ordered structure model for both Li+ and Mn2+.

    DOI: 10.1107/S1600536812035040

    Scopus

    researchmap

  • Photoluminescence properties of Ba3Si6O12N2:Eu2+ oxynitride phosphor synthesized by liquid phase precursor method Reviewed

    Y. H. Song, M. O. Kim, M. K. Jung, K. Senthil, T. Masaki, K. Toda, D. H. Yoon

    MATERIALS LETTERS   77   121 - 124   2012.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Ba3Si6O12N2 green-emitting phosphors were synthesized using oxide precursor by liquid phase precursor (LPP) method under a flowing NH3 gas. X-ray diffraction patterns showed that the prepared phosphor indicated a Ba3Si6O12N2 pure single phase. The emission spectra of synthesized phosphors under excited from UV to blue light showed a typically broad green emission wavelength which is assigned to 4f(6)5d -&gt; 4f(7) electronic transition of Eu2+ ion. Compared with emission intensity of prepared sample, the emission intensity of Ba3- Si6O12N2 green-emitting phosphors using LPP method is more than 2.5 times than that of Ba3Si6O12N2 green-emitting one by a solid state reaction method. The synthesis of phosphor using the LPP method is expected as alternative synthesis method. (C) 2012 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.matlet.2012.02.131

    Web of Science

    researchmap

  • Synthesis of high efficient Ca2SiO4:Eu2+ green emitting phosphor by a liquid phase precursor method Reviewed

    Y. Y. Luo, D. S. Jo, K. Senthil, S. Tezuka, M. Kakihana, K. Toda, T. Masaki, D. H. Yoon

    JOURNAL OF SOLID STATE CHEMISTRY   189   68 - 74   2012.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    Green emitting Eu2+-doped Ca2SiO4 phosphors were synthesized by three different methods (a conventional solid state reaction (SSR) method, a novel liquid phase precursor approach using SiO2 sol (LPP-SiO2(sol)) and water-soluble silicon compound (LPP-WSS)). The obtained phosphors exhibited a broad excitation spectrum ranging from 225 to 450 nm and a strong green emission peak at 502 nm due to the 4f(6)5d(1)-&gt; 4f(7)(S-8(7/2)) transition of Eu2+. The highest luminescent intensity was obtained for the samples fired at 1100 degrees C. The dependence of luminescence properties on Eu2+ concentration for the phosphors synthesized using LPP-WSS method was also examined from 0.1 to 5.0 mol% and the maximum emission intensity was observed at 3.0 mol% Eu2+. A detailed analysis using various characterizations revealed that phosphors produced by the LPP-WSS process exhibited more homogenous phase distribution and higher luminescence intensity than those from the other two processes, which suggested the potential application of Ca2SiO4:Eu2+ in white light-emitting diodes and fluorescence lamps. (C) 2011 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.jssc.2011.11.046

    Web of Science

    researchmap

  • Synthesis and photoluminescence properties of new NaAlSiO4:Eu2+ phosphors for near-UV white LED applications Reviewed

    Deok Su Jo, YuanYuan Luo, Karuppanan Senthil, Kenji Toda, Bong Sung Kim, Takaki Masaki, Dae Ho Yoon

    OPTICAL MATERIALS   34 ( 4 )   696 - 699   2012.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    A new NaAlSiO4:0.1Eu(2+) phosphors were synthesized at different temperatures using a liquid phase precursor (LPP) technique. The XRD patterns indicate the presence of hexagonal nepheline phase for all the samples. The synthesized phosphors can be excited efficiently in the broad near-UV region. The PL emission spectra showed a broad emission peak at around 551 nm corresponding to 5d -&gt; 41 transition of Eu2+ ions. The synthesized phosphors showed better thermal stability when compared with the standard YAG:Ce3+ phosphor. (C) 2011 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.optmat.2011.10.004

    Web of Science

    researchmap

  • New processing of LED phosphors Reviewed

    Kenji Toda

    Transactions on Electrical and Electronic Materials   13 ( 5 )   225 - 228   2012

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Korean Institute of Electrical and Electronic Material Engineers  

    In order to synthesize LED phosphor materials, we have applied three novel synthesis techniques, "melt synthesis", "fluidized bed synthesis" and "vapor-solid hybrid synthesis", in contrast with the conventional solid state reaction technique. These synthesis techniques are also a general and powerful tool for rapid screening and improvements of new phosphor materials. © 2012 KIEEME.

    DOI: 10.4313/TEEM.2012.13.5.225

    Scopus

    researchmap

  • Synthesis and Photoluminescence Properties of Green-Emitting Ba3Si6O12N2 Oxynitride Phosphor Using Boron-Coated Eu2O3 for White LED Applications Reviewed

    Y. H. Song, B. S. Kim, M. K. Jung, K. Senthil, T. Masaki, K. Toda, D. H. Yoon

    JOURNAL OF THE ELECTROCHEMICAL SOCIETY   159 ( 5 )   J148 - J152   2012

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELECTROCHEMICAL SOC INC  

    Highly efficient Ba3Si6O12N2 green-emitting phosphors using boron-coated Eu2O3 were synthesized by a gas reduction nitridation method under flowing NH3 gas. X-ray diffraction patterns showed that the synthesized phosphor was a pure phase of Ba3Si6O12N2. The Ba3Si6O12N2 green-emitting phosphors synthesized by modification of an alumina boat were crystallized much better as well as showed higher emission intensity. The emission spectra showed a typically broad green emission band attributed to the 4f(6)5d--&gt;4f(7) electronic transition of Eu2+ ions under excitation at 405 nm. The green-emitting Ba3Si6O12N2 phosphors that were synthesized using boron-coated Eu2O3 by modification of an alumina boat could be applied to generate white light emitting diodes. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.047205jes] All rights reserved.

    DOI: 10.1149/2.047205jes

    Web of Science

    researchmap

  • Combinatorial synthesis of phosphors(共著) Reviewed

    T. Ishigaki, K. Toda, M. Yoshimura, K. Uematsu, M. Sato

    Science and Technology of Advanced Materials   12   054205   2011.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/1468-6996/12/5/054205

    researchmap

  • A new raw material SiO for the synthesis of silicate phosphors Reviewed

    K. Toda

    Journal of Ceramic Processing Research   12 ( 3 )   s256 - s258   2011.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of CaMgGe2O6:Mn2+ phosphors for field emission lamps (共著) Reviewed

    S. Sato, K. Uematsu, T. Ishigaki, K.Toda, M. Sato, H. Sasaoka, M. Ooka, K. Nishimura

    Journal of Ceramic Processing Research   12 ( 3 )   s278 - s281   2011.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of Mn4+ doped red emitting phosphor for white LEDs(共著) Reviewed

    K. Seki, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Journal of Ceramic Processing Research   12 ( 3 )   s286 - s288   2011.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of Ba2SiO4:Eu2+ by a gas-solid phase method (共著) Reviewed

    T. Sakamoto, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Journal of Ceramic Processing Research   12 ( 3 )   s272 - s274   2011.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • New rare earth-free red emitting phosphor SiP2O7:Mn2+ and 4+ Under UV light excitation(共著) Reviewed

    M. Maeda, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Journal of Ceramic Processing Research   12 ( 3 )   s263 - s266   2011.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Crystal Growth of Silicate Phosphors from the Vapor Phase Invited Reviewed

    Tadashi Ishigaki, Kenji Toda, Tatsuya Sakamoto, Kazuyoshi Uematsu, Mineo Satot

    IEICE TRANSACTIONS ON ELECTRONICS   E94C ( 11 )   1745 - 1748   2011.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    Well-crystallized Ba2SiO4:Eu2+ powders were grown on a substrate by the vapor phase reaction between a mixed powder (barium carbonate and europium oxide) and SiO gas. The vaporization of SiO occurs at 1400-1600 degrees C from the SiO2 source (or SiO powder) in a reducing atmosphere. The formed SiO gas was transported by 95 vol% Ar - 5 vol% H-2 gas and reacted with the raw material powders. The emission intensity of the Ba2SiO4:Eu2+ phosphor synthesized by the new vapor phase technique is about 2.6 times higher than that of a conventional solid-state reaction sample.

    DOI: 10.1587/transele.E94.C.1745

    Web of Science

    researchmap

  • A new yellowish green NaAl(SiO4):Eu2+ phosphor for UV-LED using a liquid phase precursor process(共著) Reviewed

    D. S. Jo, K. H. Choi, K. Toda, T. Masaki, D. H. Yoon

    Jornal of Ceramic Processing Research   12 ( 1 )   s47 - s50   2011.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis and properties of Na3YSi2O7:Eu3+ phosphor for fluorescent lamp Reviewed

    T. Sakamoto, S. Kousaka, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 8, NO 9   8 ( 9 )   2731 - 2734   2011

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:WILEY-V C H VERLAG GMBH  

    Eu3+ doped Na3YSi2O7 phosphors were prepared by a solid state reaction. It was found that the excitation spectra included two regions: i.e. the broad excitation band at 237 nm and narrow peaks at 395 nm and 463 nm. The peak located at 237 nm was assigned to the combination of the charge transfer transition of O-Eu, while the peaks at 395 nm and 463 nm were assigned to the f-f transitions of Eu3+. The emission spectrum was dominated by the red peak located at 612 nm due to the electric dipole transition of D-5(0)-F-7(2). The Eu3+ doped Na3YSi2O7 phosphor was suitable for use in fluorescent lamps and white LED applications. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

    DOI: 10.1002/pssc.201084125

    Web of Science

    researchmap

  • Synthesis of Eu2+-doped A-site and oxygen-deficient perovskite related host for photoluminescent materials Reviewed

    Tadashi Ishigaki, Tomoki Hatsumori, Tatsuya Sakamoto, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 8, NO 9   8 ( 9 )   2728 - 2730   2011

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:WILEY-V C H VERLAG GMBH  

    Perovskite-related compounds have been investigated in many fields, because they have various unique properties due to their compositions and structures which are characterized by various combinations of the A and B cations. In addition, defect perovskite-type compounds have also been investigated in many areas, especially as ion conductors. In this study, we used the A-site and oxygen-deficient perovskite, Sr3Al2O6, as a photoluminescent host material. This means that the defect sites were able to substitute several ions. We investigated the A(3)Al(2)O(6):Eu2+ phosphor material (A = Mg, Ca, Sr, Ba) produced by a solid state reaction in several kinds of atmospheres. Based on our results, the phosphor showed wide excitation and emission bands of 300-400 nm and 450-600 nm, respectively. The emission color control depended on the A-site substitution ratio. It is a very useful phosphor for white LEDs. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

    DOI: 10.1002/pssc.201084140

    Web of Science

    researchmap

  • Development of gas-solid phase hybrid synthesis method of single crystal Ba2SiO4:Eu2+ Reviewed

    Tatsuya Sakamoto, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Mineo Sato

    ELECTROCERAMICS IN JAPAN XIV   485   325 - +   2011

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    We succeeded in the single crystal growth of Ba2SiO4:Eu2+ by novel synthesis method which was gas (SiO) and solid (Ba - Sc - Al - Eu - 0) phase hybridized. The Ba2SiO4:Eu2+ single crystal was synthesized by interfacial crystal growth after the reaction of the SiO gas with the surface of Ba - Sc - Al - Eu - O substrate in the reductive atmosphere. The single crystals were plate-like crystals with about 500 mu m sizes and emitted green light around 500 nm under 300 - 450 nm excitation.

    DOI: 10.4028/www.scientific.net/KEM.485.325

    Web of Science

    researchmap

  • Synthesis of anataseTiO(2) having high specific surface area from a gel precursor Reviewed

    Keiko Fukushi, Sae Nakajima, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Mineo Sato

    ELECTROCERAMICS IN JAPAN XIV   485   279 - +   2011

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    Anatase TiO2 having high temperature stability and specific surface area was synthesized using a gel precursor in very mild conditions. The precursor gel was obtained by dialysis treatment of Na16Ti10O28-HNO3 solution. The samples were characterized by X-ray diffraction analysis, transmission electronmicroscopy, Brunner-Emmett-Teller method for specific surface area measurements, and thermogravimetric analysis.

    DOI: 10.4028/www.scientific.net/KEM.485.279

    Web of Science

    researchmap

  • Microwave synthesis technique for long phosphorescence phosphor SrAl2O4:Eu2+, Dy3+ using carbon reduction Reviewed

    Tadashi Ishigaki, Hitomi Mizushina, Kazuyoshi Uematsu, Nobuhiro Matsushita, Masahiro Yoshimura, Kenji Toda, Mineo Sato

    MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS   173 ( 1-3 )   109 - 112   2010.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    As described herein, we prepared SrAl2O4:Eu2+, Dy3+ phosphor using a domestic microwave oven operated at 2.45 GHz with 500 Win 30 min, processes with carbon reduction. Using carbon as the microwave absorber it generates thermal energy. Furthermore, heating with carbon can provide a reductive atmosphere. Prepared samples emitted phosphorescence emission for a long time. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.mseb.2009.11.004

    Web of Science

    researchmap

  • Synthesis and luminescence property of new phosphate phosphor, RbPO3:Tb Reviewed

    Ayano Toda, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Mineo Sato

    MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS   173 ( 1-3 )   168 - 170   2010.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Luminescence property of a new phosphate phosphor, RbPO3:Tb, is reported in this paper. A single phase sample was obtained by thermal decomposition of a raw material mixture (RbH2PO4 and Tb4O7) at 973 K. The phosphor could be efficiently exited by the UV light, yielding an intense green emission around 550 nm. The intense green emission is originated from the f-f transition of Tb3+ ion. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.mseb.2009.12.025

    Web of Science

    researchmap

  • Low temperature synthesis method of La2O2S2 and evaluation of the photocatalytic activity Reviewed

    M. Ohashi, T. Ishigaki, K. Uematsu, K. Toda, M. Sato

    Key Engineering Materials   445   217 - 220   2010.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/www.scientific.net/KEM.445.217

    researchmap

  • Synthesis and characterization of low-dimensional structure Reviewed

    M. Nishiya, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Key Engineering Materials   445   191 - 194   2010.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/www.scientific.net/KEM.445.191

    researchmap

  • Morphology control of phosphors synthesized by microwave heating method Reviewed

    A. Toda, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Key Engineering Materials   445   233 - 236   2010.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/www.scientific.net/KEM.445.233

    researchmap

  • Melt synthesis of Eu-doped oxide phosphors using arc-imaging furnace Reviewed

    Tadashi Ishigaki, Masahiro Yoshimura, Nobuhiro Matsushita, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   30 ( 2 )   165 - 169   2010.1

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    To synthesize various complex oxide materials and their solid solutions, we applied a novel "melt-synthesis technique" rather than conventional solid-state reaction techniques. Rapid synthesis methods to develop those double oxides have been strongly anticipated. During melt synthesis, the mixture of oxides or their precursors is melted rapidly (1-60 s) in an arc-imaging furnace using strong light radiation. A spherical molten sample with multiple homogeneously mixed cations was solidified directly on a copper hearth with rapid cooling of ca. 10(2) degrees C/s.
    We studied the synthesis of A(2)BO(4) type double oxides (AA&apos;)(2)BO(4) (A= Sr(2+), Ca(2+), A&apos; = La(3+), Gd(3+), Y(3+), Eu(3+), B=Al) using this method. Homogeneous samples with Eu(3+) dopants were synthesized using liquid phase mixing in a few seconds, which is much faster than diffusions of ions in solid phase. Red fluorescence under the irradiation of ultraviolet light (254 and 365 nm) was observed. The excitation band shifted. (C) 2009 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jeurceramsoc.2009.05.040

    Web of Science

    researchmap

  • Synthesis and Characterization of CaZnGe2O6 Reviewed

    Hirotoshi Hatakeyama, Yousuke Narumi, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Mineo Sato

    ELECTROCERAMICS IN JAPAN XIII   445   187 - +   2010

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    We report the synthesis and photocatalytic activity of CaZnGe2O6, which contains Ca2+ ions and one-dimensional GeO4 chains (Ge4+: d(10) electronic configuration). This sample demonstrated the water splitting phenomenon by loading with RuO2 cocatalysis. Moreover, Ln-doped CaZnGe2O6 (where Ln = La, Ce, Pr, Nd, or Sm) shows a higher photocatalytic activity than CaZnGe2O6.

    DOI: 10.4028/www.scientific.net/KEM.445.187

    Web of Science

    researchmap

  • Development of New Red Phosphor Na3YSi2O7:Eu3+ for a white LED Reviewed

    Shinichiro Kousaka, Kenji Toda, Tadashi Ishigaki, Kazuyoshi Uematsu, Mineo Sato

    ASIAN CERAMIC SCIENCE FOR ELECTRONICS III AND ELECTROCERAMICS IN JAPAN XII   421-422   360 - +   2010

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    New red phosphors Na3YSi2O7:Eu3+ was prepared by a conventional solid-state reaction. This silicate phosphor can be efficiently excited by near UV light, yielding an intense red emission. Under the excitation of near UV light, the emission intensity is higher than that of a commercial red phosphor Y2O2S:Eu3+.

    DOI: 10.4028/www.scientific.net/KEM.421-422.360

    Web of Science

    researchmap

  • Luminescence Properties of Y(P,V)O-4 Synthesized by Microwave Heating Reviewed

    Ayano Toda, Kenji Toda, Tadashi Ishigaki, Kazuyuki Uematsu, Mineo Sato

    ASIAN CERAMIC SCIENCE FOR ELECTRONICS III AND ELECTROCERAMICS IN JAPAN XII   421-422   356 - +   2010

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    Eu3+ doped and undoped Y(P,V)O-4 phosphors were prepared using multi-mode and single-mode microwave oven operated at 2.45 GHz. In the case of the microwave heating method, the phosphor particles were non-aggregated. A homogeneous distribution of Eu ion was observed in the microwave synthesis. No sintering behavior found in the microwave heating may be attributed to a quite shorter heating time. The Eu3+ doped sample synthesized by microwave heating showed intense red emission under UV excitation.

    DOI: 10.4028/www.scientific.net/KEM.421-422.356

    Web of Science

    researchmap

  • Synthesis and luminescence properties of non-doped long persistent phosphors : Mg2SnO4 Reviewed

    Akiko Torisaka, Hiroaki Kaneko, Kentaro Nomizu, Sho Abe, Tadashi Ishigaki, Kenji Toda, Kazuyoshi Uematsu, Mineo Sato

    ASIAN CERAMIC SCIENCE FOR ELECTRONICS III AND ELECTROCERAMICS IN JAPAN XII   421-422   352 - +   2010

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    A white long persistence phosphor was synthesized in a single-phase of Mg2SnO4 which was synthesized by a solid-state reaction. This phosphor crystallized in an inverse spinel structure and showed a broad-band emission from 350nm to 700nm. The afterglow was observed upon the excitation by 254nm. A Li-doped Mg2SnO4 sample showed a higher photoluminescence intensity and a longer lifetime than the non-doped one.

    DOI: 10.4028/www.scientific.net/KEM.421-422.352

    Web of Science

    researchmap

  • Photocatalytic Activity of Bismuth Layered Perovskite Treated with Acid Reviewed

    Soihiro Watanabe, Yousuke Narumi, Kenji Toda, Tadashi Ihigaki, Kazuyoshi Uematsu, Mineo Sato

    ASIAN CERAMIC SCIENCE FOR ELECTRONICS III AND ELECTROCERAMICS IN JAPAN XII   421-422   554 - +   2010

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    We synthesized Sr0.7La0.2[ ](0.1)Bi2Ta2O9 (SBTL, [ ] vacancy), and measured their photocatalytic activity for water decomposition under UV light irradiation after acid treatment. They showed the high photocatalytic activity under UV light irradiation (H-2 evolution (213 mu mol / h), O-2 evolution (82 mu mol / h)).

    DOI: 10.4028/www.scientific.net/KEM.421-422.554

    Web of Science

    researchmap

  • Novel Ba-Sc-Si-oxide and oxynitride phosphors for white LED Reviewed

    Tomoyuki Nakano, Yoshitaka Kawakami, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Mineo Sato

    JOURNAL OF LUMINESCENCE   129 ( 12 )   1654 - 1657   2009.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Alkaline earth silicates. which comprise a host material doped with rare-earth minerals, show excellent luminescence properties with various crystal structures and high stability. From results of this study, we report luminescence properties of Ba(9)Sc(2)Si(6)O(24):Eu(2+) and Ba(9)Sc(2+delta)Si(6)O(24+3 delta)N(3 delta):Eu(2+) as a novel alkaline earth silicate and silicon oxynitride phosphors for white LEDs Using a conventional solid-state reaction, Ba(9)Sc(2)Si(6)O(24):Eu(2+) samples were synthesized and Ba(9)Sc(2+delta)Si(6)O(24+3 delta)N(3 delta):Eu(2+) samples were obtained by nutrization of Ba(9)Sc(2+delta)Si(6)O(24):Eu(2+) The samples can be excited by blue light, exhibiting green (Ba(9)Sc(2)Si(6)O(24):Eu(2+)) and yellow (Ba(9)Sc(2+delta)Si(6)O(24+3 delta)N(3 delta):Eu(2+)) efficiently, which are emissions for use in white LEDs essentially. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jlumin.2009.04.028

    Web of Science

    researchmap

  • Structure and luminescence of sodium and lanthanide(III) coordination polymers with pyridine-2,6-dicarboxylic acid Reviewed

    Taoyun Zhu, Kazuya Ikarashi, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Hirokazu Okawa, Mineo Sato

    INORGANICA CHIMICA ACTA   362 ( 10 )   3407 - 3414   2009.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    A series of coordination polymers constructed by sodium, lanthanide(III), and pyridine-2,6-dicarboxylate (dipic),NaLn(dipic)(2) center dot 7H(2)O (Ln = Eu, Gd, Tb), have been prepared under a hydrothermal condition. The crystal structures of the three compounds which are isostructual were determined by single-crystal X-ray diffraction. The two-dimensional layers found in the compounds are built up from six-folded {NaO(6)} polyhedra and nine-folded {LnN(2)O(7)} polyhedra, these being edge-shared each other along the c axis and bridged by carboxylate groups of dipic along the b axis, respectively. This two-dimensional framework provides cavities inside the layer and interlayer spaces outside the layer for accommodation of the two dipic molecules coordinated to a lanthanide(III) ions. The dehydrated materials obtained by heating the as-synthesized crystals at 200 degrees C held their crystal structure, and absorbed the same amounts of water molecules as those of the as-synthesized crystals upon the exposure of 100% relative humidity at room temperature. The Eu and Tb compounds showed strong red and green emissions, respectively, due to an energy transfer from dipic molecules to trivalent emission ions. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.ica.2009.01.036

    Web of Science

    researchmap

  • One-dimensional coordination polymers of praseodymium(III)-vanadium(V) complexes with pyridine-2,6-dicarboxylic acid Reviewed

    Taoyun Zhu, Koichi Murokawa, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Hirokazu Okawa, Mineo Sato

    POLYHEDRON   28 ( 11 )   2196 - 2200   2009.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    This paper represents the hydrothermal synthesis of new isomorphous lanthanide-vanadium complexes with one-dimensional coordination polymers: [Pr(2)(VO(2))(2)(dipic)(4)(H(2)O)(9)] center dot nH(2)O with dipic = pyridine-2,6-dicarboxylic acid and n = 7.75. The structure determination shows a unique one-dimensional structure in which three types of chains run along the c-axis: the chain of positively charged praseodymium complexes bridged by a dipic ligand ([Pr(dipic)(H(2)O)5](+)), the chain of negatively charged, stacked vanadium complexes ([VO(2)(dipic)](-)), and the chain of neutral praseodymium complexes with a bridged dipic ligand and a coordinating dipic ligand ([Pr(dipic)[VO(2)(dipic)](H(2)O)(4)]). Such one-dimensional chains provide open channels which can accommodate water molecules. Not only accommodated water molecules but also ones coordinated to praseodymium ions were easily removed and absorbed upon heating at 200 degrees C and exposure of humidity at room temperature, respectively. (C) 2009 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.poly.2009.01.010

    Web of Science

    researchmap

  • Low Temperature Synthesis of TiO2 from Acid Solution Reviewed

    S. Watanabe, S. Nkajima, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Key Engineering Materials   421-422   498 - 501   2009.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/www.scientific.net/KEM.421-422.498

    researchmap

  • New Titanium Oxide Compound for Photocatalytic Water Splitting, Hydrous Na16Ti10O28 Reviewed

    S. Nakajima, S. Watanabe, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Key Engineering Materials   421-422   546 - 549   2009.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/www.scientific.net/KEM.421-422.546

    researchmap

  • One-dimensional channels constructed from hydrogen bonding networks among 4,4 &apos;-bipyridine units and water molecules available for accommodation of polyoxomolybdate clusters Reviewed

    Hidekazu Kobayashi, Kazuya Ikarashi, Kazuyoshi Uematsu, Kenji Toda, Hirokazu Okawa, Zhu Taoyun, Mineo Sato

    INORGANICA CHIMICA ACTA   362 ( 1 )   238 - 242   2009.1

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    A hybrid coordination complex, [(H(5)O(2))(H(2)bpy)(bpy)(4)][NaMo(8)O(26)]center dot 2H(2)O (bpy = 4,4-bipyridine), was synthesized via hydrothermal reactions at 150 degrees C. The structure consists of two moieties; one is an infinite chain of beta-[Mo(8)O(26)] clusters, each of which is inter-linked up by a sodium ion, and the other a two-dimensional network constructed from doubly protonated bpy ions and its neutral molecules, which are linked with water molecules by hydrogen bonds. The stacking of the networks provides one-dimensional tunnels suitable for Na-beta-[Mo(8)O(26)] chains. (c) 2007 Published by Elsevier B.V.

    DOI: 10.1016/j.ica.2007.07.040

    Web of Science

    researchmap

  • Metastable Sr0.5TaO3 Perovskite Oxides Prepared by Nanosheet Processing Reviewed

    Keigo Inaba, Shinya Suzuki, Yuji Noguchi, Masaru Miyayama, Kenji Toda, Mineo Sato

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY   2008 ( 35 )   5471 - 5475   2008.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY-BLACKWELL  

    Metastable Sr0.5TaO3 with a perovskite structure was prepared by using layer-structured H2Sr1.5Ta3O10 by two different processes: direct dehydration and nanosheet processing, and the photocatalylic activities of the obtained structures were investigated for the evolution of H-2 and O-2 from distilled water under UV light irradiation. The average gas evolution rates were 66 mu mol h(-1) (H-2) and 1.6 mu mol h(-1) (O-2) for Sr0.5TaO3 prepared by direct dehydration, whereas those obtained by nanosheet processing were 1.26 mu mol h(-1) (H-2) and 33 mu mol h(-1) (O-2). It was shown that nanosheet processing is effective for obtaining metastable Sr0.5TaO3 with high photocatalytic activities. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

    DOI: 10.1002/ejic.200800776

    Web of Science

    researchmap

  • Morphology Cntrol of High Luminance Phosphors

    K. Toda, M. Hosoume, K. Sato, K. Uematsu, M. Sato, A. watanabe, T. Fukui

    Key Engineering Materilas   388   107 - 110   2008.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/0-87849-359-x.107

    researchmap

  • Melt synthesis of oxide phosphors with K(2)NiF(4) structures: CaLa(1-x)Eu(x)GaO(4)

    Tadashi Ishigaki, Kenji Toda, Tomoaki Watanabe, Naonori Sakamoto, Nobuhiro Matsushita, Masahiro Yoshimura

    JOURNAL OF MATERIALS SCIENCE   43 ( 14 )   4749 - 4752   2008.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER  

    In order to synthesize compounds of various Perovskite-related structures, we have utilized a novel "melt synthesis technique" for phosphors rather than the conventional solid state reaction techniques. The solid state reactions require multi-step processes of heating/cooling with intermediate grindings to make homogeneous samples. However, for the melt synthesis, it is possible to make a homogeneous sample in a single step within a short period of time (1-60 s) due to the liquid phase reaction in the molten samples, which were melted by strong light radiation in an imaging furnace. In this study, we have prepared a red-phosphor CaLaGaO(4):Eu(3+) which has a perovskite-related layered K(2)NiF(4) structure. Well-crystallized CaLa(1-x) Eu (x) GaO(4) samples with the K(2)NiF(4) structure have been obtained up to x = 0.25, but there was the formation of an olivine phase when x = 0.5-1.0. The red emission at 618 nm increased with the increasing value of x up to x = 0.25.

    DOI: 10.1007/s10853-008-2481-9

    Web of Science

    researchmap

  • Synthesis and Luminescence Property of Blue Phosphor, BaMgAl<SUB>10</SUB>O<SUB>17</SUB>:Eu<SUP>2+</SUP>, by the Flash-Creation-Method

    WATANABE Akira, FUKUI Takehisa, NOGI Kiyoshi, TODA Kenji, KAWADA Satoshi, SHIRAKURA Shigeki, HOSOUME Masafumi, UEMATSU Kazuyoshi, SATO Mineo

    Journal of High Temperature Society   Vol.34 ( 3 )   130 - 135   2008.5

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:High Temperature Society of Japan  

    BaMgAl<SUB>10</SUB>O<SUB>17</SUB>:Eu<SUP>2+</SUP> is a promising blue phosphor for lump, CRT and PDP. Conventionally, the BAM phosphors synthesize by the solid-state reaction from the mixture of oxide or carbonate starting materials. The solid-state reaction needs high temperature to get well-crystallized single phase. However, the control of particle morphology and size distribution is difficult for such a high temperature synthesis. In this study, we reported new synthetic technique using flash creation method derived nanopowder precursor. In the new technique, well-crystallized single phase phosphors were obtained at 1400°C for 6h. Although the powders were grown into the plate-like particles, the BAM powders retain the nano-size morphology after annealing. The emission intensity under UV excitation of Ba<SUB>0.9</SUB>Eu<SUB>0.1</SUB>MgAl<SUB>10</SUB>O<SUB>17</SUB> from the FCM-derived nanopowder was 110% compared with phosphors prepared by the conventional solid-state reaction. The excitation intensity under VUV (146nm) of the FCM derived nanopowder was 159% of the conventional solid-state reaction.

    DOI: 10.7791/jhts.34.130

    CiNii Article

    researchmap

  • Reinvestigation of layered poly[aqua-sodium(I) [[aquasamarium(III)]-di-mu-aqua-mu(3)-pyridine-2,6-dicarboxylato-mu(2)-pyridine-2,6-dicarboxylato] trihydrate]

    Kazuya Ikarashi, Taoyun Zhu, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   63 ( 8 )   M2203 - U1635   2007.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:BLACKWELL PUBLISHING  

    The crystal structure of the title compound, {[NaSm(C7H3- NO4)(2)(H2O)(4)]center dot 3H(2)O}(n), was first reported by van Albada, Gorter & Reedijk [(1999), Polyhedron, 18, 1821-1824]. It has now been reinvestigated and confirmed from single-crystal data, giving greater understanding of the role of the water molecules. The two-dimensional layers found in the compound are built up from six-coordinate NaO6 polyhedra and nine-coordinate SmN2O7 polyhedra. The former share edges with each other along the c axis and the latter are bridged by carboxylate groups of pyridine-2,6-dicarboxylate anions along the b axis. Eight-membered rings of water molecules, connected to one another by hydrogen bonding, are formed in the interlayer spaces.

    DOI: 10.1107/S160053680702884X

    Web of Science

    researchmap

  • Lanthanum-indium oxysulfide as a visible light driven photocatalyst for water splitting Reviewed

    Kiyonori Ogisu, Akio Ishikawa, Kentaro Teramura, Kenji Toda, Michikazu Hara, Kazunari Domen

    CHEMISTRY LETTERS   36 ( 7 )   854 - 855   2007.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CHEMICAL SOC JAPAN  

    La-In-based oxysulfide is demonstrated to act as a photocatalyst for the reduction of H+ to H-2 and the oxidation of H2O to O-2 in the presence of sacrificial reagents under visible light (420 &lt; A &lt; 480 nm). Loading with IrO2 is effective for promoting O-2 evolution, while Pt is effective as a cocatalyst for H-2 evolution.

    DOI: 10.1246/cl.2007.854

    Web of Science

    researchmap

  • Solid Chemical Reaction by Microwave Heating for the Synthesis of LiFePO4 Cathode Material Reviewed

    K.. Uematsu, A. Ochiai, K. Toda, M. Sato

    Journal of Ceramic Society of Japan   115 ( 7 )   450 - 454   2007.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.2109/jcersj.115.450

    researchmap

  • Superconductivity of Layered Perovskite Synthesized by Soft Chemistry Reviewed

    T. Teranishi, S. Takezawa, K. Toda, H. Ishikawa, K. sato, K. Uematsu, M. Sato

    Key Engineering Materials   350   163 - 166   2007.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/0-87849-449-9.163

    researchmap

  • Electrochemical performance of Al-doped LiMn2O4 prepared by different methods in solid-state reaction Reviewed

    Teruaki Kakuda, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    JOURNAL OF POWER SOURCES   167 ( 2 )   499 - 503   2007.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Al-doped LiMn2O4 cathode materials synthesized by a newly developed wet-milling method and a dry process method using a conventional solid-state reaction were evaluated physicochemically and electrochemically. In the wet-milling method, a precursor was made from the raw materials atomized by a wet milling. A good cyclic performance was obtained for the LiMn2O4 samples prepared by the wet-milling method, achieved up to 99% of retention of capacity at 50 degrees C at the 30th cycle. The precursor obtained by the wet-milling method was well homogenous and highly reactive due to their finely ground particles, giving good crystallinity to LiMn2O4 products. (C) 2007 Published by Elsevier B.V.

    DOI: 10.1016/j.jpowsour.2007.01.035

    Web of Science

    researchmap

  • Synthesis of Blue Phosphor, BaMgAl10O17: Eu2+, from the Flash Creation Method Derived Nanopowder Reviewed

    A. Watanabe, T. Fukui, Y. Ito, M. Hosoume, S. Shirakura, S. Kawada, K. Toda, K. Uematsu, M. Sato

    ITE LETTERS   8 ( 1 )   38 - 41   2007.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • 透光性酸化イットリウム(Y2O3)焼結体の作製 Reviewed

    齋藤紀子, 渡邊良二, 瀬山博之, 戸田健司, 大滝浩通, 堀田憲康

    Journal of the Materials Science Society of Japan   44 ( 1 )   272 - 277   2007.2

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)  

    researchmap

  • Origin and model for cooperative host-guest interaction affecting the orientation of guests in oriented nematic hosts Reviewed

    Michio Kobayashi, Ken-ichi Kumagai, Toshihiko Hoshi, Takuya Yamaguchi, Hirobumi Sato, Kenji Toda, Yoshie Tanizaki, Tetsutaro Yoshinaga

    MOLECULAR CRYSTALS AND LIQUID CRYSTALS   469   31 - 49   2007

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:TAYLOR & FRANCIS LTD  

    It has been observed for the binary systems of oriented nematic hosts and nonmesomorphic guests (substituted anthraquinones) that the orientational orders of amino-substituted anthraquinones ascend with increasing guest concentrations. A new quantitative anti experimental procedure has been proposed for obtaining the host-guest isotropic dispersion, isotropic electrostatic, anisotropic dispersion, and anisotropic electrostatic interaction energies. Among these four host-guest interaction energies, the host-guest isotropic dispersion interaction energy alone is demonstrated to be well correlated with the concentration dependence of the orientational order of the guest. A model is also proposed for the cooperative and isotropic host-guest interaction.

    DOI: 10.1080/1542140070143187

    Web of Science

    researchmap

  • Removal of Fluorinefrom Waste Water by Ettringite Reviewed

    T. Tokumitsu, K. Toda, H. Morinaga, K. Sato, K. Uematsu, M. Sato

    ITE LETTERS   7   352 - 355   2006.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Self Assemble Synthesis of Potassium Niobate at Room Temperature Reviewed

    K. Toda, A. Sugawara, K. Uematsu, M. Sato, M. Osada

    Key Engineering Materials   320   7 - 10   2006.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/0-87849-411-1.7

    researchmap

  • New silicate phosphors for a white LED Invited Reviewed

    Kenji Toda, Yoshitaka Kawakami, Shin-ichiro Kousaka, Yutaka Ito, Akira Komeno, Kazuyoshi Uematsu, Mineo Sato

    IEICE TRANSACTIONS ON ELECTRONICS   E89C ( 10 )   1406 - 1412   2006.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    We focus on the development of new silicate phosphors for a white LED. In the europium doped silicate system, four LED phosphor candidates-Li2SrSiO4:Eu2+, Ba9Sc2Si6O24:Eu2+, Ca3Si2O7:Eu2+ and Ba2MgSi2O7:Eu2+ were found. Luminescent properties under near UV and visible excitation were investigated for the new Eu2+ doped LED silicate phosphors. These new phosphors have a relatively strong absorption band in a long wavelength region.

    DOI: 10.1093/ietele/e89-c.10.1406

    Web of Science

    researchmap

  • Development of an open-ended coaxial line probe for measurement of dielectric properties of inorganic materials at high temperature Reviewed

    Kazuyoshi Uematsu, Jyunji Tsuchida, Mineo Sato, Kenji Toda

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY   89 ( 8 )   2638 - 2640   2006.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:BLACKWELL PUBLISHING  

    An open-ended coaxial line probe for dielectric measurements at high temperatures was developed. The probe, which was fabricated using stainless steel as the center and outer conductors and quartz wool as an insulator, can function well up to 800 degrees C. The dielectric properties of the raw materials and resultant materials were measured using a network analyzer that was equipped with the open-ended coaxial line probe at high temperatures to clarify the formation reaction process of YVO4:Eu3+ and Mg2SnO4:Mn2+ phosphors using a microwave heating method. The developed probe was confirmed to be effective for reaction-process analyses at high temperatures.

    DOI: 10.1111/j.1551-2916.2006.01074.x

    Web of Science

    researchmap

  • Luminescence properties of long-persistence silicate phosphors Reviewed

    Y Ito, A Komeno, K Uematsu, K Toda, M Sato

    JOURNAL OF ALLOYS AND COMPOUNDS   408   907 - 910   2006.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    Tb3+-doped and (Ce3+, Tb3+)-codoped Ca0.5Sr1.5Al2SiO7 were prepared using a solid-state reaction at 1273 K for 3 h in air and 1623 K for 6 h in a weakly reductive atmosphere of 5% H-2-95% N-2 gas. The resultant (Ce3+, Tb3+)-codoped Ca0.5Sr1.5Al2SiO7 phosphor shows four main emission peaks: one at 386 run for Ce3+ and three at 483, 542 and 591 nm for Tb3+. Emission intensity of Tb3+ in the (Ce3+, Tb3+)-codoped phosphor was five times greater than that of the Tb3+ single-doped phosphor because of the energy transfer from Ce3+ to Tb3+. The codoped phosphor showed long-persistence white phosphorescence. (c) 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jallcom.2005.01.132

    Web of Science

    researchmap

  • VUV phosphors in the SrO-B2O3-P2O5 ternary system Reviewed

    Y Komatsu, A Komeno, K Toda, K Uematsu, M Sato

    JOURNAL OF ALLOYS AND COMPOUNDS   408   903 - 906   2006.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    Photoluminescence properties under vacuum ultraviolet (VUV, 147 nm) excitation were investigated for a new borophosphate compound. The new phosphor, Sr6BP5O20, has a relatively strong absorption band in a short wavelength region because of the strong covalent characters of B-O and P-O bonds. The phosphor activated by Eu2+ showed a strong blue luminescence. The luminance is about 2.2 times as bright as a commercial blue phosphor, BaMgAl10O17:Eu2+. The phosphor is an attractive candidate of new phosphors for plasma display panels and mercury-free fluorescent lamps. (c) 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jallcom.2005.01.098

    Web of Science

    researchmap

  • Recent research and development of VUV phosphors for a mercury-free lamp Reviewed

    K Toda

    JOURNAL OF ALLOYS AND COMPOUNDS   408   665 - 668   2006.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    This study specifically addresses development of new inorganic oxide phosphors for a Xe-discharge mercury-free lamp. We describe the relationship between the luminescence property under vacuum ultraviolet (VUV) excitation and the crystal structure of new VUV phosphors. (c) 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jallcom.2005.01.080

    Web of Science

    researchmap

  • VUV properties of Eu-doped alkaline earth magnesium silicate Reviewed

    A Komeno, K Uematsu, K Toda, M Sato

    JOURNAL OF ALLOYS AND COMPOUNDS   408   871 - 874   2006.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    Plasma display panels (PDP) are most promising for large flat panel displays at present. However, luminescence efficiency and lifetime of PDP phosphors should be improved. Alkaline earth silicates show remarkable properties as phosphor hosts with various crystal structures and high chemical stability. Availability of Ba2MgSi2O7 has received attention as a host for vacuum ultraviolet (VUV) excitable phosphor. Blue-green phosphor Ba2MgSi2O7:Eu2+ with a high thermal quenching temperature [G. Blasse, W.L. Wanmaker, J.W. ver Vrugt, A. Bril, Philips. Res. Rep. 23 (1968) 189-200] exhibit high luminance (45% of commercial green VUV phosphor Zn2SiO4:Mn2+) under VUV excitation without optimization of synthesis condition and emission color. Ba2MgSi2O7 is promising candidate for the new VUV phosphor in PDP and mercury-free lamp application. (c) 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jallcom.2005.01.070

    Web of Science

    researchmap

  • Characterization of YVO4 : Eu3+ phosphors synthesized by microwave heating method Reviewed

    K Uematsu, A Ochiai, K Toda, M Sato

    JOURNAL OF ALLOYS AND COMPOUNDS   408   860 - 863   2006.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    YVO4:Eu3+ phosphors were prepared using a domestic microwave oven operated at 2.45 GHz with 500 W. The temperature of raw materials with mixtures of Y2O3, V2O5 and Eu2O3 that were irradiated with the microwave increased to about 840 degrees C within 150 s. Subsequently, the temperature dropped sharply in spite of the continuing microwave irradiation. Measurement of the dielectric loss factor of the raw materials and products at 2.45 GHz at temperatures from 25 degrees C to 800 degrees C revealed a high absorption efficiency of microwave energy by V2O5, which provided a rapid increase in the raw material's temperature. A low dielectric loss factor observed for YVO4:Eu engendered a sharp temperature drop after completion of the reaction of Y2O3 with V2O5, (c) 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jallcom.2005.01.081

    Web of Science

    researchmap

  • Luminescent properties of red long persistence phosphors, BaMg2Si2O7 : Eu2+, Mn2+ Reviewed

    S Abe, K Uematsu, K Toda, M Sato

    JOURNAL OF ALLOYS AND COMPOUNDS   408   911 - 914   2006.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    Long persistence phosphors of BaMg2Si2O7:Eu2+, Mn2+, with red emission were prepared using a conventional solid state reaction. Phosphors doped only With Eu2+ emitted 1400 nm violet light; those doped only with Mn2+ emitted red light that was hardly visible. Phosphors doped with both Eu2+ and Mn2+ showed two emission peaks of 400 and 660 nm, exhibiting a reddish luminescence to the naked eye. These facts suggested an energy transfer from Eu2+ to Mn2+. Non-stoichiometric co-doped phosphors with a deficient Ba component showed long persistence phosphorescence with reddish color. (c) 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jallcom.2005.03.092

    Web of Science

    researchmap

  • Powder neutron diffraction study of layered perovskite, KCa 2Nb3O10 Reviewed

    Toshiaki Tokumitsu, Kenji Toda, Tsukuru Aoyagi, Daiki Sakuraba, Kazuyoshi Uematsu, Mineo Sato

    Journal of the Ceramic Society of Japan   114 ( 1333 )   795 - 797   2006

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Ceramic Society of Japan  

    Crystal structure of a layered perovskite, KCaiNbjOm, was determined by the Rietveld refinement method for a powder neutron diffraction pattern. The compound crystallizes a monoclinic system with a space group P21/m (No. 11) and lattice parameters of a = 0.77418 (6) nm, 6 = 0.77073(6) nm, c = 1.4859(1) nm, β = 97.51(1)°.

    DOI: 10.2109/jcersj.114.795

    Scopus

    researchmap

  • Removal of fluoride from aqueous solution by ettringite Reviewed

    Toshiaki Tokumitsu, Kenji Sato, Kenji Toda, Hiroko Morinaga, Kazuyoshi Uematsu, Mineo Sato

    Journal of the Ceramic Society of Japan   114 ( 1332 )   729 - 732   2006

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Ceramic Society of Japan  

    In order to purify waste water containing fluoride, the calcium additive method has usually been used to recover fluoride ions in the form of refractory calcium fluoride. In this case, the removable fluoride concentration is limited to be 10-15 mg/1 due to the solubility of calcium fluoride. In this study, we report 3CaO·Al2O3·3CaSO4· 32H2O (ettringite) as a highly absorbent substance for the fluoride. The fluoride concentration of the water treated with the ettringite was achieved to be less than 8 mg/l without sludge.

    DOI: 10.2109/jcersj.114.729

    Scopus

    researchmap

  • Possibility of superconductivity in a layered perovskite niobate, KCa 2Nb3O10, synthesized by an ion exchange reaction Reviewed

    Sachi Takezawa, Takashi Teranishi, Hironori Ishikawa, Toshiaki Tokumitsu, Kenji Toda, Kazuyoshi Uematsu, Mineo Sato

    Journal of the Ceramic Society of Japan   114 ( 1334 )   861 - 865   2006

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Ceramic Society of Japan  

    We prepared low temperature phase of triple layered perovksite KCa 2Nb3O10 by an ion-exchange reaction. Liintercalated low temperature phase, Li0.79KCa2Nb 3O10, shows strong diamagnetic signal around at 7.8 K. The magnetic phase transition temperature of Li-intercalated low temperature phase is higher than that of Li-interca-lated high temperature phase.

    DOI: 10.2109/jcersj.114.861

    Scopus

    researchmap

  • Synthesis of KNbO3 thin film by self-assembly of perovskite nanosheets Reviewed

    A. Sugawara, K. Uematsu, K. Toda, M. Sato

    Transactions of the Materials Research Society of Japan   30   583 - 586   2005.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • New Tantalum Oxynitride Photocatalyst Reviewed

    K. Toda, Y. Yamanaka, T. Matsumto, H. Sato, K. Uematsu, M. Sato, N. Hotta

    Transactions of the Materials Research Society of Japan   30   465 - 468   2005.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • New Phosphors for Mercury-free Illumination Reviewed

    K. Toda, Y. Ito, M. Kawamoto, Y. Komatsu, A. Komeno, K. Uematsu, M. Sato

    Transactions of the Materials Research Society of Japan   30   433 - 436   2005.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Al粉末の浮上式窒化反応によるAlN微粉末の合成と表面改質 Reviewed

    堀田憲康, 橋本賢太, 戸田健司, 鷲山宏治, 堀田幹則, 北條純一

    Journal of the Materials Science Society of Japan   42 ( 5 )   272 - 277   2005.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:日本材料科学会  

    CiNii Article

    CiNii Books

    researchmap

  • Ionic Conductivity of Layered Borate (NaxBa1-x/2)Al2B2O7 Reviewed

    A. Komeno, Y. Aoyama, K. Uematsu, K. Toda, M. Sato

    ITE LETTERS   6   331 - 334   2005.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of Thin Film by Self-Assembly of Perovskite Nanosheets Reviewed

    A. Sugawara, K. Uematsu, K. Toda, M. Sato

    Key Engineering Materials   301   99 - 102   2005.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/0-87849-982-2.99

    researchmap

  • 長残光蛍光体Sr2MgSi2O7:Eu,Dyのゾルゲル合成 Reviewed

    白倉重樹, 戸田健司, 今成裕一郎, 野々川貴志, 上松和義, 佐藤峰夫, 西須佳宏, 小林幹男

    Journal of Ceramic Society of Japan   113   442 - 445   2005.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.2109/jcersj.113.484

    researchmap

  • Synthesis of Nitride Compounds Using Fluidized Bed Reviewed

    Y. Yamanaka, K. Toda, T. Matsumoto, K. Uematsu, M. Sato, N. Hotta

    Key Engineering Materials   301   231 - 234   2005.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/0-87849-982-2.231

    researchmap

  • Self-Assembly of Perovskite Nanosheet Colloid at Room Temperature Reviewed

    K. Toda, H. Sato, A. Sugawara, S. Tokuoka, K. Uematsu, M. Sato

    Key Engineering Materials   301   227 - 230   2005.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.4028/0-87849-982-2.227

    researchmap

  • Overall water splitting on (Ga1-xZnx)(N1-xOx) solid solution photocatalyst: Relationship between physical properties and photocatalytic activity Reviewed

    K Maeda, K Teramura, T Takata, M Hara, N Saito, K Toda, Y Inoue, H Kobayashi, K Domen

    JOURNAL OF PHYSICAL CHEMISTRY B   109 ( 43 )   20504 - 20510   2005.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER CHEMICAL SOC  

    The physical and photocatalytic properties of a novel solid solution between GaN and ZnO, (Ga1-xZnx)(Ni1-xOx), are investigated. Nitridation of a mixture of Ga2O3 and ZnO at 1123 K for 5-30 h under NH3 flow results in the formation of a (Ga1-xZnx)(N1-xOx) solid solution with x = 0.05-0.22. With increasing nitridation time, the zinc and oxygen concentrations decrease due to reduction of ZnO and volatilization of zinc, and the crystallinity and band gap energy of the product increase. The highest activity for overall water splitting is obtained for (Ga1-xZnx)(N1-xOx) with x = 0.12 after nitridation for 15 h. The crystallinity of the catalyst is also found to increase with increasing the ratio of ZnO to Ga2O3 in the starting material, resulting in an increase in activity.

    DOI: 10.1021/jp053499y

    Web of Science

    researchmap

  • Photocatalytic water splitting on Ni-intercalated Ruddlesden-Popper tantalate H2La2/3Ta2O7 Reviewed

    K Shimizu, S Itoh, T Hatamachi, T Kodama, M Sato, K Toda

    CHEMISTRY OF MATERIALS   17 ( 20 )   5161 - 5166   2005.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER CHEMICAL SOC  

    A series of Ruddlesden-Popper-type hydrous layered perovskites, A'(2)ATa(2)O(7) (A' = H or K, A = La-2/3 or Sr), were presented as novel catalysts for photocatalytic water splitting into H-2 and O-2 under UV irradiation. These hydrous perovskites showed higher activity than anhydrous perovskites (KTaO3, La1/3TaO3) for overall splitting of water. Results of photoluminescence spectroscopy and H-2 evolution from aqueous n-butylamine solution support the hypothesis that the high activity of the hydrous perovskites results from their hydrated layered structure, where the photogenerated electrons and holes can be effectively transferred to the intercalated substrates (H2O and n-butylamine). Addition of Ni cocatalyst to H2La2/3Ta2O7 via an ion-exchange reaction increased the activity, while Ni addition did not improve the activity of H2SrTa2O7. Ni K-edge EXAFS/XANES, UV-vis spectroscopy, and TEM results for Niloaded catalysts indicate that Ni2+ ions and small NiO clusters are intercalated into the layers of H2La2/3Ta2O7, while relatively large NiO particles at the external surface of the perovskite are the main Ni species in H2SrTa2O7. Thus, the highly dispersed Ni(II) species at the interlayer space are shown to act as effective sites for H-2 evolution in the photocatalytic water splitting.

    DOI: 10.1021/cm050982c

    Web of Science

    researchmap

  • Preparation of KNbO3 thin film by self-assembly of perovskite nanosheet Reviewed

    K Toda, A Sugawara, K Uematsu, M Sato

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   44 ( 9B )   6973 - 6976   2005.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN SOC APPLIED PHYSICS  

    Potassium niobate thin films with a perovskite structure were prepared by a new nanosheet self-assembly technique on a SiO2 glass substrate. A homogeneous nanosheet precursor solution was obtained by dissolving layered perovskite K2NbO3F in water at room temperature without any modifier. It was confirmed by X-ray diffraction that the films have a pseudocubic perovskite structure and show continuous transformation from layered perovskite K2NbO3F to perovskite KNbO3. The ultraviolet-vi sib le absorption spectra of the films showed an increase in absorbance with the thickness of thin films, suggesting the growth of a self-assembled multilayer consisting of perovskite nanosheets and K+ ions.

    DOI: 10.1143/JJAP.44.6973

    Web of Science

    researchmap

  • Photocatalytic performance of Ba5Ta4O15 to decomposition of H2O into H-2 and O-2 Reviewed

    H Otsuka, KY Kim, A Kouzu, Takimoto, I, H Fujimori, Y Sakata, H Imamura, T Matsumoto, K Toda

    CHEMISTRY LETTERS   34 ( 6 )   822 - 823   2005.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CHEMICAL SOC JAPAN  

    The photocatalytic performance of barium tantalates in the decomposition of H2O into H-2 and O-2 was investigated. Ba5Ta4O15 that was prepared under Ta rich atmosphere exhibited remarkable photocatalytic activity. Under the same reaction conditions, its activity was the highest among all of the alkali earth-tantalum mixed-oxide photocatalysts prepared.

    DOI: 10.1246/cl.2005.822

    Web of Science

    researchmap

  • Preparation of YVO4 : Eu3+ phosphor using microwave heating method Reviewed

    K Uematsu, K Toda, M Sato

    JOURNAL OF ALLOYS AND COMPOUNDS   389 ( 1-2 )   209 - 214   2005.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    YVO4:Eu3+ phosphor was prepared using a domestic microwave oven operated at a frequency of 2.45 GHz and a power of 500 W. The temperature of raw materials, mixtures of Y2O3, V2O5 and Eu2O3, irradiated with the microwave was rose up to about 1113 K in 150 s, followed by a sharp drop in the temperature in spite of irradiating the microwave continuously. From the measurement of a dielectric loss factor of the raw materials at 2.45 GHz, a high absorption of microwave energy by V2O5 was found to provide an increase in temperature of the mixture. On the other hand, a low dielectric loss factor of YVO4 caused the sharp drop in temperature as soon as the reaction of Y2O3 with V2O5 was completed. (C) 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jallcom.2004.05.083

    Web of Science

    researchmap

  • Synthesis and luminescence properties of new long persistent phosphors. Reviewed

    A. Komeno, Y. Ito, S. Abe, K. Uematsu, K. Toda, M. Sato

    TRANSACTIONS OF THE MATERIALS RESEARCH SOCIETY OF JAPAN, VOL 30, NO 4   30 ( 4 )   1053 - 1056   2005

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:ELSEVIER SCIENCE BV  

    Long persistent phosphors are materials which can absorb visible light energy to show afterglow. Previously, alkaline earth metal sulfides and zinc sulfides doped radioactive materials were used for the long persistent phosphors. However, sulfides tend to deteriorate upon expose of moisture in air. On the other hand, though the radio luminous phosphors give long afterglows, radioactive materials have serious influence on environment. The highly stable and highly luminescent long persistent phosphors without radioactive materials are desired.
    In this study, silicate families were chosen as hosts because of their excellent physical and chemical stability. The Ca0.5Sr1.5Al2SiO7: Ce3+, Tb3+ phosphor showed the fluorescence of 5 times as high radiation intensity as the Ce3+ single-doped phosphor. The cause is energy migration from Ce3+ to Tb3+. The co-doped phosphor showed white long-persistent phosphorescence. The non-stoichiometric BaMg2Si2O7: Eu2+ Mn2+ phosphors with a Ba-deficient component exhibiting a long persistent phosphorescence with reddish color with two emission peaks of 400 mn and 660 nm. The cause is energy migration from Eu2+ to Mn2+. The afterglows of these long persistent phosphors are occurred by sensitization between co-doped ions.

    Web of Science

    researchmap

  • Synthesis of nitride compound using fluidized bed Reviewed

    Yoshiomi Yamanaka, Kenji Toda, Kazuyoshi Uematsu, Mineo Sato, Noriyasu Hotta

    Transactions of the Materials Research Society of Japan, Vol 30, No 4   30 ( 4 )   1089 - 1092   2005

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:ELSEVIER SCIENCE BV  

    Compositionally uniformed nitride powders (GaN and GaN-ZnO solid solution) were synthesized from metal oxide powders using a fluidized bed in a NH3 and/or a N-2 flow. GaN was synthesized by a two-step heating; the first step was done at 700 degrees C for 1 h, and the second step was done at 900 degrees C for 4h. A GaN-ZnO solid solution was synthesized at 900 degrees C for 4h. The synthesized nitride powders were characterized by powder X-ray diffraction (XRD). Optical properties of the products were examined by UV-Vis diffuse reflectance spectra. The grain size of the products was smaller than that of the starting materials. On the other hand, the crystallite size of the GaN-ZnO solid solution was almost the same as that of the starting material of Ga2O3.

    Web of Science

    researchmap

  • Synthesis of phosphor materials using silica sand Reviewed

    Takashi Nonogawa, Yu-Ichiro Imanari, Kenji Toda, Shigeki Shirakura, Kazuyoshi Uematsu, Mineo Sato, Ayano Toda, Yoshihiro Nishisu, Mikio Kobayashi

    Journal of the Ceramic Society of Japan   113 ( 1318 )   442 - 445   2005

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Ceramic Society of Japan  

    The silica sand is primarily composed of high purity SiO2. Mt. Iide over Niigata, Yamagata and Fukushima prefectures is known as a rich mine for silica sand. In this study, we adopted natural resource (silica sand from Mt. Iide, Osodani area) as a starting material for the synthesis of akermanite type long-persistent phosphor Sr2MgSi2O7: Eu2+, Dy3+. The silica sand derived (Sr 0.98Eu0.01Dy0.01)2MgSi 2O7 showed long afterglow phenomena. Therefore, the silica sand can be potentially used in preparing silicate phosphors.

    DOI: 10.2109/jcersj.113.442

    Scopus

    researchmap

  • Combinatorial screening and QSAR modeling in the SrO-B2O3-P2O5 ternary system to search for thermally stable blue phosphors for PDPs Reviewed

    KS Sohn, JG Yoo, N Shin, K Toda, DS Zang

    JOURNAL OF THE ELECTROCHEMICAL SOCIETY   152 ( 12 )   H213 - H218   2005

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELECTROCHEMICAL SOC INC  

    The need to identify a thermally stable blue phosphor for plasma display panels (PDPs) is vital, because the currently used BaMgAl10O17:Eu2+ (BAM) phosphors have serious thermal degradation problems. In this respect, we report on the screening of a Eu2+-doped SrO-B2O3-P2O5 system by a combinatorial chemistry technique so that combinatorial libraries could be developed in terms of luminance and color chromaticity. As a quantitative structure activity relationship (QSAR) model, a continuous luminance map was obtained as a function of composition using an artificial neural network trained using the results from the combinatorial screening. Promising photoluminescence was found in a lineshape composition range in the SrO-B2O3-P2O5 ternary library, and the samples in this composition range were crystallized into a single major phase of Sr6BP5O20:Eu2+ in an I $(4) over bar $ c2 symmetry with cell parameters a=9.784 and c=19.01. The luminance of Sr6BP5O20:Eu2+ was 2.8 times as high as BAM under vacuum ultraviolet (VUV) excitation and underwent negligible thermal degradation, even though the CIE color chromaticity was somewhat poor. (c) 2005 The Electrochemical Society. All rights reserved.

    DOI: 10.1149/1.2083208

    Web of Science

    researchmap

  • Preparation of KNbO3 Nanoparticles at Room Temperature Reviewed

    K. Toda, H. Sato, A. Sugawara, S.Tokuoka, K. Uematsu, M. Sato, A. A. Bokov, Z-G. Ye

    Key Engineering Materials   269   165 - 168   2004.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Influence of High-Temperature Treatment of Silica Gel and Porous Glass on Concentration of Tritiated Water by Adsorption Method Reviewed

    UEMATSU Kazuyoshi, TODA Kenji, SATO Mineo

    RADIOISOTOPES   53 ( 8 )   435 - 443   2004.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Japan Radioisotope Association  

    <I>Silica gels and porous glasses thermally treated at various temperatures were examined for use as an adsorbent to separate tritiated water</I> (HTO) <I>with an adsorption method. The</I> HTO <I>was adsorbed much stronger than</I> H<SUB>2</SUB>O. <I>A high partition coefficient of 1.38 was observed for the thermally treated silica gel at 1100°C in vacuo. From the measurement of</I> IR <I>spectra, isolated silanol groups were formed on the thermally treated silica gel surface. We can conclude that there is a large mass effect for the concentration of tritiated water on the thermally treated silica gels because hydroxyl groups or water molecules adsorbed on them are difficult to form hydrogen bonds with each other.</I>

    DOI: 10.3769/radioisotopes.53.435

    CiNii Article

    researchmap

  • Colloid Chemistry of Layered Perovskite Niobate Reviewed

    K. Toda, K. Shimizu, H. Sato, A. Sugawara, K. Uematsu, M. Sato

    Transactions of the Materials Research Society of Japan   29   2399 - 2402   2004.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Structural Characterization of Bismuth Layered Perovskite Treated with Acids Reviewed

    T. Aoyagi, K. Toda, K. Uematsu, M. Sato

    Key Engineering Materials   269   181 - 184   2004.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Structure Analysis of A-Site Defect Perovskite-Type Crystal Reviewed

    A. Komeno, Y. Aoyama, K. Toda, M. Sato, K. Uematsu

    Key Engineering Materials   269   11 - 14   2004.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Mechanoluminescen Phenomenon of Niobates Reviewed

    D. Sakuraba, K. Toda, K. Uematsu, M. Sato

    Key Engineering Materials   269   99 - 104   2004.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Enhanced electrochemical performance of LiFePO4 prepared by hydrothermal reaction Reviewed

    S Tajimi, Y Ikeda, K Uematsu, K Toda, M Sato

    SOLID STATE IONICS   175 ( 1-4 )   287 - 290   2004.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Well-crystalline LiFePO4 particles were prepared by a hydrothermal reaction. The particles thus prepared by adding polyethylene glycol (PEG) to the starting reaction solution were fine crystalline in the range of 0.5-1.5 mum with a narrow particle size distribution. The initial discharge capacity of the sample as a lithium secondary battery was achieved to 143 mAhg(-1) at 0.5 mA cm(-2) (corresponding to 35 mA g(-1)) larger than that of the sample prepared by the hydrothermal method without PEG. The increase in the initial discharge capacity should be correlated with the change in particle size and degree of crystallization. (C) 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.ssi.2003.12.033

    Web of Science

    researchmap

  • Intelligent reactions of inorganic phosphor materials with microwave heating Reviewed

    K Uematsu, K Toda, M Sato

    CHEMISTRY LETTERS   33 ( 8 )   990 - 991   2004.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CHEMICAL SOC JAPAN  

    YVO4:Eu3+ and Mg2SnO4:Mn2+ phosphors were prepared using a domestic microwave oven. The temperature of the raw materials irradiated with a microwave was rose up to 1111-1716 K within 150 s, followed by a sharp drop in the temperature in spite of irradiating the microwave continuously. A low dielectric loss factor of the reaction products caused the sharp drop in temperature as soon as the reaction was completed.

    DOI: 10.1246/cl.2004.990

    Web of Science

    researchmap

  • Photocatalytic water splitting on hydrated layered perovskite tantalate A(2)SrTa(2)O(7)center dot nH(2)O ( A = H, K, and Rb) Reviewed

    K Shimizu, Y Tsuji, T Hatamachi, K Toda, T Kodama, M Sato, Y Kitayama

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   6 ( 5 )   1064 - 1069   2004

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    A series of layered perovskite tantalates, A(2)SrTa(2)O(7) (A=H, Li, K, and Rb), were prepared as novel photocatalysts for photocatalytic water splitting into H-2 and O-2 under UV irradiation. The layered perovskite tantalates with hydrated interlayer space, A(2)SrTa(2)O(7).nH(2)O (A=H, K, and Rb), showed higher H-2 formation rate than anhydrous layered tantalate, Li2SrTa2O7, and anhydrous perovskite tantalate, KTaO3. H2SrTa2O7.nH(2)O and K2SrTa2O7.nH(2)O showed high activity for overall splitting of water without loading co-catalysts. The reaction over H2SrTa2O7.nH(2)O proceeded steadily more than 70 h, demonstrating a high durability of the catalyst. Effects of hydrated interlayer space on the catalytic activity were discussed on the basis of the results of photoluminescence spectra and the hydrogen evolution from aqueous solution of n-butylamine as a test reaction. The results indicate that the availability of interlayer space of layered tantalate as reaction sites is an important factor to improve the photocatalytic activity of Ta-based semiconductor materials.

    DOI: 10.1039/b312620j

    Web of Science

    researchmap

  • セルフラックス法による真空紫外励起蛍光体の合成 Reviewed

    稲田直樹, 戸田健司, 上松和義, 佐藤峰夫, 西須佳宏, 小林幹男

    Journal of Ecotechnology Research   9   143 - 147   2003.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)  

    researchmap

  • Research and Characterization of the Phosphor for Mercury-free Fluorescent Lamps Reviewed

    K. Toda, Y. Imanari, T. Nonogawa, K. Uematsu, M. Sato

    Transactions of the Materials Research Society of Japan   28   1247 - 1250   2003.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of KNbO3 in Water Reviewed

    K. Toda, S. Tokuoka, N. Ohtake, K. Uematsu, M. Sato

    Transactions of the Materials Research Society of Japan   28   353 - 356   2003.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Reaction Mechanism of Perovskite KNbO3 in Aqueous Solution Reviewed

    K. Toda, S. Tokuoka, N. Ohtake, K. Uematsu, M. Sato

    Key Engineering Materials   248   27 - 30   2003.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Low Temperature Synthesis of Titanium oxide Reviewed

    K. Toda, M. Kawakami, K. Uematsu, M. Sato

    Transactions of the Materials Research Society of Japan   28   313 - 316   2003.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Low Temperature Synthesis of Titania and Titanates Reviewed

    K. Toda, M. Kawakami, K. Uematsu, M. Sato

    Key Engineering Materials   248   107 - 110   2003.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Characterization of Phosphors in the Eu-doped Sr-Al-B-O system Reviewed

    MIYOSHI Jun-ichi, TODA Kenji, UEMATSU Kazuyoshi, SATO Mineo, NISHISU Yoshihiro, KOBAYASHI Mikio

    J.Ecotech.Res   9 ( 2 )   137 - 142   2003.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:International Association of Ecotechnology Research  

    Phosphor materials have been searched in the Sr-Al-B-O system. For a molar ratio (Sr<SUB>1-x</SUB>Eu<SUB>x</SUB>) : Al : B = 1 : 2 : 2 (x = 0.01), a crystalline layered compound SrAl<SUB>2</SUB>B<SUB>2</SUB>O<SUB>7</SUB>:Eu<SUP>2+</SUP> was synthesized at 900 °C for 12 h in a reductive atmosphere. The SrAl<SUB>2</SUB>B<SUB>2</SUB>O<SUB>7</SUB>:Eu<SUP>2+</SUP> showed blue emission under UV (254 nm) and VUV (Vacuum Ultraviolet, 146 nm) excitation. For the ratio (Sr<SUB>1-x</SUB>Eu<SUB>x</SUB>) : Al : B = 2 : 2 : 2 (x = 0.01), a transparent glass and SrAl<SUB>2</SUB>O<SUB>4</SUB> component with a long afterglow phosphorescence was found.

    DOI: 10.11190/jer.9.137

    CiNii Article

    CiNii Books

    researchmap

    Other Link: https://jlc.jst.go.jp/DN/JLC/20007068193?from=CiNii

  • Green VUV phosphor with spinel structure, Mg1-xZnxAl2-yGayO4:Mn Reviewed

    K. Toda, Y. Imanari, R. Arai, K. Uematsu, M. Sato, K. Ohno, S. Miyazaki

    Journal of Materials Science Letters   22 ( 13 )   979 - 980   2003.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    A green-emitting vacuum ultraviolet (VUV) phosphor, Mg1-xZnxal2-y-gayO4:Mn was synthesized by the conventional solid state reaction. The composition, Mg0.88Zn0.10Mn0.02Al2O4, shows the highest brightness under VUV excitation, which corresponds to about 13 times higher than that of sodium salicylate as a reference material.

    DOI: 10.1023/A:1024621214914

    Scopus

    researchmap

  • New VUV phosphor, NaLnGeO4:Eu3+ (Ln = rare earth) Reviewed

    Kenji Toda, Yu-Ichiro Imanari, Takashi Nonogawa, Kazuyoshi Uematsu, Mineo Sato

    Chemistry Letters   32 ( 4 )   346 - 347   2003.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Chemical Society of Japan  

    The synthesis and luminescence properties of Eu3+-doped ordered olivine-type NaLnGeO4 (Ln = rare earth) phosphors are reported. Under vacuum-UV (VUV) excitation, this phosphor showed intense red emission due to the 5D0-7F2 transition. The Na(Y0.3Gd0.65Eu0.05)GeO4 phosphor with optimum composition and synthetic condition under 147 nm excitation were higher than those of (Y0.95Eu0.05)2O3.

    DOI: 10.1246/cl.2003.346

    Scopus

    researchmap

  • Synthesis of phosphor materials using natural ore "serpentine" Reviewed

    Yu-Ichiro Imanari, Takashi Nonogawa, Jun-Ichi Miyoshi, Kenji Toda, Kazuyoshi Uematsu, Mineo Sato, Katsunori Kosuge, Yoshihiro Nishisu, Mikio Kobayashi

    Journal of the Ceramic Society of Japan   111 ( 1290 )   151 - 154   2003

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Ceramic Society of Japan  

    Serpentine is a hydrated ultra-mafic rock, which is primarily composed of magnesium silicate minerals such as chrysotile and antigorite. Fibrous chrysotile is the most common type of asbestos. Since the rich mines supplied serpentine in Japan, application of natural ore "serpentine" as raw materials for ceramics has one of the potentially lowest cost ceramics production. In this study, long afterglow phosphor, Sr2MgSi2O7, has been successfully synthesized using natural ore serpentinite. Eu2+ and Dy3+ co-doped compounds show long-lasting phosphorescence. This demonstrates that the "serpentine" could be used in preparing alkaline earth silicate phosphors.

    DOI: 10.2109/jcersj.111.151

    Scopus

    researchmap

  • 層状ペロブスカイトの光触媒特性 Reviewed

    川上正人, 辻由浩, 清水研一, 上松和義, 戸田健司, 佐藤峰夫, 北山淑江

    Journal of Ecotechnology Research   8   47 - 52   2002.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)  

    researchmap

  • Preparation of iron phosphate cathode material of Li3Fe2(PO4)(3) by hydrothermal reaction and thermal decomposition processes Reviewed

    M Sato, S Tajimi, H Okawa, K Uematsu, K Toda

    SOLID STATE IONICS   152   247 - 251   2002.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Well-crystallized Li3Fe2(PO4)(3) with an orthorhombic beta-Fe-2(SO4)(3)-type structure was able to be synthesized by using two synthetic routes, where hydrothermal reaction and successive heat treatment with relatively low temperatures were employed. The samples prepared were found to show orthorhombic symmetry, contrary to the fact that a conventional solid state synthesis heating at temperatures higher than 1000 degreesC usually gives monoclinic symmetry. The sample showed two plateau potentials of 2.8 and 2.7 V vs. Li/Li+ upon discharge, and the total discharge capacity of the sample exhibited more than 80 mA h g(-1) under 0.5 mA cm(-2). (C) 2002 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0167-2738(02)00306-5

    Web of Science

    researchmap

  • Synthesis and characterization of Perovskite-type ionic conductor: Li3yLa1-3y(Nb1-xWx)3O9 Reviewed

    Y. Aoyama, A. Komeno, K. Toda, M. Sato

    Key Engineering Materials   216   135 - 140   2002.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • New synthetic route of perovskite materials in the test tube Reviewed

    K. Toda, K. Uematsu, N. Ohtake, S. Tokuoka, M. Sato

    Ceramic Engineering and Science Proceedings   23   689 - 694   2002.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)  

    researchmap

  • Search for new vacuum-UV phosphors Reviewed

    K. Toda, K. Uematsu, Y. Imanari, T. Nonogawa, M. Sato

    Ceramic Engineering and Science Proceedings   23   861 - 868   2002.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)  

    researchmap

  • Room temperature synthesis and characterization of perovskite compounds Reviewed

    K Toda, S Tokuoka, K Uematsu, M Sato

    SOLID STATE IONICS   154   393 - 398   2002.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    A new soft chemical method has been developed to remove the rock-salt type layers in the Ruddlesden-Popper-type layered perovskite at room temperature. The rock-salt type (KF) blocks in the layered perovskite, K2NbO3F, were selectively dissolved into water to give three-dimensional perovskite, KNbO3, at room temperature. In the alkali metal aqueous solution, the ion-exchange reaction of parent layered compound with coexisting ions in the alkaline solution results in the new perovskites containing the other metal ions for the A-site. The development of this synthetic route could lead to interesting new metastable perovskite materials at low temperature. (C) 2002 Published by Elsevier Science B.V.

    DOI: 10.1016/S0167-2738(02)00578-7

    Web of Science

    researchmap

  • Photocatalytic water splitting over spontaneously hydrated layered tantalate A2SrTa2O7·nH2O (A=H, K, Rb) Reviewed

    Ken-Ichi Shimizu, Yoshihiro Tsuji, Masato Kawakami, Kenji Toda, Tatsuya Kodama, Mineo Sato, Yoshie Kitayama

    Chemistry Letters   ( 11 )   1158 - 1159   2002.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Chemical Society of Japan  

    A series of layered perovskite-type tantalates with hydrated interlayer space, A2SrTa2O7·nH2O (A=H, K, Rb), exhibited efficient photocatalytic activity for water splitting into H2/O2 mixture under UV irradiation without loading metal co-catalysts.

    DOI: 10.1246/cl.2002.1158

    Scopus

    researchmap

  • Characterization of potassium niobate produced by self-assembled nanosheet from aqueous solution Reviewed

    K Toda, N Ohtake, M Kawakami, S Tokuoka, K Uematsu, M Sato

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   41 ( 11B )   7021 - 7024   2002.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN SOC APPLIED PHYSICS  

    Submicron particles of potassium niobate KNbO3 were prepared by a colloid chemistry method. A rock-salt-type KF block in a layered perovskite, K2NbO3F, with a K2NiF4 type structure was selectively dissolved in water to produce perovskite nanosheets at room temperature. The self-assembly between perovskite nanosheets in a colloidal solution may enable shape control of potassium niobate powder. The microstructure, phase transition and mechanism of the solution process were investigated by transmission electron microscopy, X-ray diffraction and determination of ultraviolet-visible absorption spectra. [DOI: 10.1143/JJAP.41.7021].

    DOI: 10.1143/JJAP.41.7021

    Web of Science

    researchmap

  • Synthesis and characterization of new long persistent phosphor Reviewed

    K Toda, Y Imanari, T Nonogawa, J Miyoshi, K Uematsu, M Sato

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   110 ( 4 )   283 - 288   2002.4

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Rare earth-doped alkaline earth silicates, Sr2MgSi2O7:Eu2+, Dy3+ and Ca2MgSi2O7: Eu2+, Dy3+, with an akermanite-type structure show bright and long-lasting phosphorescence. After irradiation by a white-color fluorescent lamp (780 lm) for 5 min, the light blue emission of Sr2MgSi2O7: Eu2+, Dy3+ was observable by naked eye in the dark for over 100 min after removal of the excitation light source.

    DOI: 10.2109/jcersj.110.283

    Web of Science

    researchmap

  • Crystal structure of trivalent ion conductive perovskite: Y-x(Ta3xW1-3x)O-3 Reviewed

    K Toda, Y Aoyama, M Sato

    ASIAN CERAMIC SCIENCE FOR ELECTRONICS II AND ELECTROCERAMICS IN JAPAN V, PROCEEDINGS   228-2   277 - 280   2002

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:TRANS TECH PUBLICATIONS LTD  

    Crystal structure of A-site deficient perovskites, Y-x(Ta3xW1-3x)O-3 was determined by the Rietveld refinement method for neutron diffraction pattern. The Rietveld refinement indicates that a disorder-type compound with x = 0.06 crystallizes the orthorhombic system with the space group Pnma (No. 62) and lattice parameters a = 0.5373(3), b = 0.7547(5) and c = 0.5297(3) nm. The crystal structure of disorder-phase is a GdFeO3 type orthorhombic structure with no evidence for long range ordering of the vacancies in the partially occupied A-site.

    Web of Science

    researchmap

  • New Synthetic Route of Perovskite Material in the Test Tube Reviewed

    K. Toda, S. Tokuoka, K. Uematsu, M. Sato

    Key Engineering Materials   214-215   67 - 72   2001.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Crystal Structure of Fe16N2 Reviewed

    K. Toda, M. Honda, Y. Orihara, M. Sato, F. Kanamaru

    Key Engineering Materials   181-182   213 - 216   2000.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Physical Properties of Non-Stoichiometric Rare Earth Orthoniobates Reviewed

    K. Toda, M. Honda, Y. Ishimoto, M. Sato

    Key Engineering Materials   181-182   217 - 220   2000.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Single Crystal Growth of Lithium Ion Conductive Phosphates Reviewed

    T. Suzuki, N. Hayakawa, K. Uematsu, K. Toda, M. Sato

    Key Engineering Materials   181-182   183 - 186   2000.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Trivalent Ionic Conductivity of Perovskite-Type Yx(Ta3xW1-3x)O3 Reviewed

    N. Sakai, K. Toda, M. Sato

    Electrochemistry   68   504 - 506   2000.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Oxygen defect in non-stoichiometric europium orthoniobate, EuxNbO4-1.5(1-x) Reviewed

    Kenji Toda, Masahito Honda, Yoko Ishimoto, Zuo-Guang Ye, Mineo Sato

    Solid State Ionics   136-137   25 - 30   2000.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier Science Publishers B.V.  

    The crystal chemistry of non-stoichiometric europium orthoniobate, EuxNbO4-1.5(1-x), prepared using Rb2CO3 flux, was studied. The lattice parameters vary clearly with the rare earth content of the orthoniobate specimens. In the Eu2O3-Nb2O5 system without a flux, the non-stoichiometric compound could not be synthesized as a single phase. With the use of flux, europium-deficient non-stoichiometric solid solution appears to form in which oxygen vacancies are the predominant defects. These non-stoichiometric compounds have the potential to act as new oxide ion conductors.

    DOI: 10.1016/S0167-2738(00)00384-2

    Scopus

    researchmap

  • Enhancement of discharge capacity of Li3V2(PO4)3 by stabilizing the orthorhombic phase at room temperature Reviewed

    Mineo Sato, Hirokazu Ohkawa, Kenji Yoshida, Mai Saito, Kazuyoshi Uematsu, Kenji Toda

    Solid State Ionics   135 ( 1-4 )   137 - 142   2000.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier Science Publishers B.V.  

    Li3V2(PO4)3 and solid solutions of Li3-2x(V1-xZrx)2(PO4)3 were prepared by a solid state reaction. A high temperature orthorhombic phase of Li3V2(PO4)3 with a β-Fe2(SO4)3-type was successfully stabilized at room temperature by substituting Zr for V with substitution ratios beyond x = 0.05. The pure material of Li3V2(PO4)3 exhibited a cathode performance with two well defined regions of plateau at around 3.7 and 4.1 V vs. Li/Li+ upon charging and 3.6 and 4.0 V vs. Li/Li+ upon discharging, respectively, suggesting two types of phases produced upon the charge/discharge process. On the other hand, the cathode performance of the orthorhombic stabilized materials showed almost the same charge/discharge voltages as those of the pure material, but, with two plateaus slightly sloping, showed a considerably improved charge/discharge cycle performance compared to that of the pure material. Such improvement on the charge/discharge cycle performance is suggested to come from the disordered lithium ion arrangement in the orthorhombic phase.

    DOI: 10.1016/S0167-2738(00)00292-7

    Scopus

    researchmap

  • Synthesis and characterization of ionic conductors; Li12/7+x(Li4/7Ti24/7-xMx)O-8 (M=Al, Cr and Fe) and Li12/7+2x(Li4/7Ti24/7-2xMg2x)O-8 with tunnel structure Reviewed

    N Sakai, K Toda, M Sato, F Kanamaru

    ELECTROCERAMICS IN JAPAN III   181-1   167 - 170   2000

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:TRANS TECH PUBLICATIONS LTD  

    Web of Science

    researchmap

  • New layered perovskite compound synthesized by the soft chemistry: KCa2Ta3O10 Reviewed

    K. Toda, S. Takakuwa, N. Sakai, T. Teranishi, M. Sato

    Key Engineering Materials   169-170   231 - 234   1999.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Synthesis of Ruddlesden-Popper type (La,Sr)n+1VnO3n+1 (n = 1, 2, 3) Reviewed

    M. Suzuki, F. Kanamaru, K. Toda, T. Sakai

    Key Engineering Materials   169-170   239 - 242   1999.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • The ionic conductivity of new ionic conductor Li3(In1-xScx)2(PO4)3 Reviewed

    T. Suzuki, K. Yoshikawa, N. Hayakawa, K. Uematsu, K. Toda, M. Sato

    Key Engineering Materials   169-170   205 - 208   1999.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Preparation and ionic substitution of Dion-Jacobson type compounds CsLa(M,Mn) nO3n+1 (M = Nb, n = 2, 3) Reviewed

    S. Takakuwa, T. Saitoh, K. Toda, F. Kanamaru

    Key Engineering Materials   169-170   243 - 246   1999.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Structure and property of layered perovskite type compounds (La,Sr)n+1FenO3n+1 and intercalation of LaSr3Fe3O10-delta Reviewed

    T. Nishi, K. Toda, F. Kanamaru, T. Sakai

    Key Engineering Materials   169-170   235 - 238   1999.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Structural chemistry of new ion-exchangeable tantalates with layered perovskite structure: New Dion-Jacobson phase MCa2Ta3O10 (M = alkali metal) and Ruddlesden-Popper phase Na2Ca2Ta3O10 Reviewed

    K. Toda, T. Teranishi, Z-G. Ye, M. Sato

    Materials Research Bulletin   34   971 - 982   1999.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/S0025-5408(99)00084-7

    researchmap

  • Improvement of discharge capacity of β-Fe2(SO4)3-type Li3V2(PO4)3 by stabilizing high temperature orthorhombic phase at room temperature Reviewed

    Hirokazu Ohkawa, Kenji Yoshida, Mai Saito, Kazuyoshi Uematsu, Kenji Toda, Mineo Sato

    Chemistry Letters   ( 10 )   1017 - 1018   1999

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Chemical Society of Japan  

    The cathode performance of a lithium ion battery was investigated for β-Fe2(SO4)3-type Li3V2(PO4)3 and Li3(V1 xZrx)2(PO4)3 (x=0.05, 0.1, 0.15, 0.2). On TG-DTA measurements, Li3V2(PO4)3 exhibited two types of phase transition, while Li3(V1-xZrx)2(PO4)3 exhibited no phase transition. Powder X-ray diffraction analysis and conductivity measurements confirmed an evidence for the stabilization of the high temperature phase at room temperature. The discharge capacity of the Zr-substituted Li3(V1-xZrx)2(PO4)3 samples became much larger than that of the pure Li3V2(PO4)3 sample.

    DOI: 10.1246/cl.1999.1017

    Scopus

    researchmap

  • Single crystal growth and domain structure of CsLaTa2O7 Reviewed

    S Tobitsuka, T Honma, T Wakayama, K Toda, M Sato

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   19 ( 6-7 )   1559 - 1562   1999

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    A new layered perovskite compound of CsLaTa2O7 was synthesized and grown in the forms of powder and single crystal by a conventional solid state reaction and a flux method, respectively. The Rietveld analysis based on the powder sample showed a tetragonal system, while the observation of the as-grown single crystal by a polarized light microscope showed an orthorhombic system. The orthorhombic as-grown single crystal transformed to a tetragonal phase on annealing at a high temperature. (C) 1999 Elsevier Science Limited. All rights reserved.

    DOI: 10.1016/S0955-2219(98)00476-2

    Web of Science

    researchmap

  • Synthesis and lithium ionic conductivity of Li3-2x(In1-xZrx)(2)(PO4)(3) (0 &lt;= x &lt;= 0.20) Reviewed

    K Yoshikawa, N Hayakawa, T Suzuki, K Uematsu, K Toda, M Sato

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   19 ( 6-7 )   879 - 882   1999

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Lithium ion conductors, Li3-2x(In1-xZrx)(2)(PO4)(3) (0 less than or equal to x less than or equal to 0.20), were synthesized by a solid state reaction. A superionic conductive phase of Li3In2(PO4)(3) was stabilized down to room temperature, assisted by the substitution of Zr4+ for In3+ sites of Li3In2(PO4)(3). TG-DTA analysis indicated no phase transition in the samples with x superior to 0.05. The substituted samples showed much higher ionic conductivity by a couple of magnitude than that of Li3In2(PO4)(3). In particular, the highest conductivity at room temperature was 1.42 x 10(-5) Scm(-1) for Li-2.8(In0.9Zr0.1)(2)(PO4)(3). Thin films with the composition of Li-2.8(In0.9Zr0.1)(2) (PO4)(3) was prepared by a sol-gel method. A coating solution was made from lithium isopropoxide, indium isopropoxide, zirconium isopropoxide and diphosphorus pentaoxide. Well crystallized films were obtained on silicon dioxide and quartz glass substrates by dropping the coating solution, followed by firing over 873 K. In the temperatures above 473 K the lithium ionic conductivity of the film was slightly higher than that of sintered samples prepared by the solid state reaction at 1373 K. (C) 1999 Elsevier Science Limited. All rights reserved.

    DOI: 10.1016/S0955-2219(98)00336-7

    Web of Science

    researchmap

  • Synthesis and structure determination of reduced tantalates, Li2LaTa2O7, Li2Ca2Ta3O10 and Na2Ca2Ta3O10, with a layered perovskite structure Reviewed

    Kenji Toda, Masaki Takahashi, Takashi Teranishi, Zuo-Guang Ye, Mineo Sato, Yukio Hinatsu

    Journal of Materials Chemistry   9 ( 3 )   799 - 803   1999

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    New reduced tantalates, Li2LaTa2O7, Li2Ca2Ta3O10 and Na2Ca2Ta3O10, with a layered perovskite structure have been synthesized by a chemical or an electrochemical intercalation reaction of the alkali metal cations with the parent Dion-Jacobson series compounds. The crystal structures of these compounds were determined by Rietveld analysis of powder X-ray diffraction patterns, and found to be analogous to those of the parent compounds. The intercalation of the lithium ion leads to a large contraction along the stacking direction of perovskite layers because of a higher interlayer charge density. These intercalation compounds are the first example of reduced tantalates with a layered perovskite structure.

    DOI: 10.1039/a807038e

    Scopus

    researchmap

  • Possibility of superconductivity in new reduced tantalate and titanate with the layered perovskite structure Reviewed

    K Toda, T Teranishi, M Sato

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   19 ( 6-7 )   1525 - 1529   1999

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    New reduced tantalate, Na2Ca2Ta3O10, and titanate, Na1.0Ca0.95La2Ti3O10, were synthesized by intercalation reaction from the parent Dion-Jacobson and Ruddlesden-Popper type layered perovskite compounds. The crystal structure of the tantalate was determined by the Rietveld analysis of the powder X-ray diffraction pattern. The intercalation compound, Na2Ca2Ta3O10, is the first example of reduced tantalate with the Ruddlesden-Popper type structure. In some of reduced tantalate and titanate compounds, the diamagnetic signals have been observed below 7 K. Therefore, these compounds are thought to be good candidates for new oxide superconductors. (C) 1999 Elsevier Science Limited All rights reserved.

    DOI: 10.1016/S0955-2219(98)00472-5

    Web of Science

    researchmap

  • Structure refinement of lithium ion conductors Li3Sc2(PO4)(3) and Li3-2x(Sc1-xMx)(2)(PO4)(3) (M = Ti, Zr) with x = 0.10 by neutron diffraction Reviewed

    T Suzuki, K Yoshida, K Uematsu, T Kodama, K Toda, ZG Ye, M Ohashi, M Sato

    SOLID STATE IONICS   113   89 - 96   1998.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    The crystal structure of lithium ion conductors, Li3Sc2(PO4)(3) and Li3-2x(Sc1-xMx)(2)(PO4)(3) (M = Ti, Zr) with x = 0.10, were refined by Rietveld analysis for neutron diffraction patterns in order to confirm the site location and site occupancy for Li ions. The Rietveld refinement confirmed that a high disorder was introduced to three kinds of Li sites in the high temperature superionic conduction phase of Li3Sc2(PO4)(3). The high temperature phase was stabilized at room temperature by substituting Ti4+ or Zr4+ for Sc3+ sites. The stabilized materials were also found to have similar high disorder over the Li sites. (C) 1998 Published by Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0167-2738(98)00279-3

    Web of Science

    researchmap

  • Lithium intercalation and cathode performance of Li2CrTi (PO4)(3) Reviewed

    M Sato, S Hasegawa, K Yoshida, K Toda

    DENKI KAGAKU   66 ( 12 )   1236 - 1240   1998.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELECTROCHEMICAL SOC JAPAN  

    Chemical and electrochemical lithium intercalation behavior was investigated on Li2CrTi(PO4)(3). Lithium ions with an almost one mole per formula were inserted by the chemical intercalation by n-butyllithium. The structure refinement was done by the Rietveld method for both parent and intercalated materials. The results showed that both materials crystallized in a lower crystal symmetry, R (3) over bar or C2/c, which is different from that previously reported in the literature. The intercalated material exhibited a cathode performance with a plateau at around 2.8 V vs. Li/Li+ upon charging and 2.4 V vs. Li/Li+ upon discharging.

    Web of Science

    researchmap

  • Structural chemistry of new ion-exchangeable tantalates with layered perovskite structure: New reduced Ruddlesden-Popper phase, Na2Ca2Ta3O10 Reviewed

    K Toda, T Teranishi, M Takahashi, ZG Ye, M Sato

    SOLID STATE IONICS   113   501 - 508   1998.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    A new reduced tantalate, Na2Ca2Ta3O10, with layered perovskite structure was synthesized by an intercalation reaction from the parent sodium compound, NaCa2Ta3O10, The crystal structures of these compounds were determined by the Rietveld analysis of powder X-ray diffraction pattern. Although the framework of the perovskite layer of intercalation compound is analogous to that of the parent compound, the coordination of interlayer sodium ion in the intercalation compound is clearly distinct from that of the parent compound. The sodium ions within the interlayer of intercalation compound have a rock-salt coordination because of a too strong repulsive force fas a tetrahedral coordination. The intercalation compound, Na2Ca2Ta3O10, is the first example of a reduced! tantalate with a Ruddlesden-Popper type structure. (C) 1998 Published by Elsevier Science BN. All rights reserved.

    DOI: 10.1016/S0167-2738(98)00316-6

    Web of Science

    researchmap

  • Cathode Characteristics of Lithium Transition Metal Phosphate Synthesized by Ion-exchange Reaction Reviewed

    K. Yoshida, K. Toda, K. Uematsu, M. Sato

    Key Engineering Materials   157-158   289 - 296   1998.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Chemical and electrochemical intercalation of lithium into the tantalates with the layered perovskite structure Reviewed

    K Toda, M Takahashi, T Teranishi, K Uematsu, M Sato

    DENKI KAGAKU   66 ( 12 )   1241 - 1247   1998.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELECTROCHEMICAL SOC JAPAN  

    New reduced tantalates, Li2LaTa2O7 and Li2Ca2Ta3O10, with layered perovskite structure were synthesized by electrochemical or chemical intercalation reaction of lithium from the parent Dion-Jacobson series compounds. The crystal structures of these compounds were determined by the Rietveld analysis of powder X-ray diffraction pattern. The crystal structures of intercalation compounds were analogous to those of the parent compounds. The intercalation of the lithium ion leads to a large contraction along the stacking direction of perovskite layers because of a higher interlayer charge density. These intercalation compounds are the first example of reduced tantalates with layered perovskite structure.

    Web of Science

    researchmap

  • Synthesis, Structure and Properties of the Magnetic Relaxor Ferroelectric Pb(Fe2/3W1/3)O3 [PFW] Reviewed

    Z-G. Ye, K. Toda, M. Sato, E. Kita, H. Schmid

    Journal of Korean Physical Society   32   1028 - 1031   1998.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    researchmap

  • Concentration quenching of the Eu3+-activated luminescence in some layered perovskites with two-dimensional arrangement Reviewed

    Toshihiko Honma, Kenji Toda, Zuo-Guang Ye, Mineo Sato

    Journal of Physics and Chemistry of Solids   59 ( 8 )   1187 - 1193   1998

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier Ltd  

    The quenching of Eu3+-emission in the layered perovskite compounds SrRE2Al2O7, BaRE2Ti3O10, RETa3O9 and RbRETa2O7 (RE = rare earths) with two-dimensional arrangement of rare earth ions was investigated. The highest luminescence intensity was observed in both tantalum compounds, RETa3O9 and RbRETa2O7. The concentration quenching found in these compounds can be explained by a percolation model with two-dimensional interactions between the Eu3+ sites in the host lattice. The energy transfer between the Eu3+ ions takes place by the multipole-multipole interaction among the nearest-neighbor sites in the rare earth sublattice. © 1998 Elsevier Science Ltd. All rights reserved.

    DOI: 10.1016/S0022-3697(98)00056-0

    Scopus

    researchmap

  • Stabilization of superionic conduction phase in Li3Sc2(PO4)(3) Reviewed

    T Suzuki, K Yoshida, K Uematsu, T Kodama, K Toda, ZG Ye, M Sato

    SOLID STATE IONICS   104 ( 1-2 )   27 - 33   1997.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Lithium superion conductors, Li3+2x(Sc1-xMgx)(2)(PO4)(3), Li3-2x(Sc1-xMx)(2)(PO4)(3) (M=Ti, Zr, Sn, Hf) and Li3-4x(Sc1-xMx)(2)(PO4)(3) (M = Nb, Ta) were prepared by a solid-state reaction. TG-DTA analysis indicated no phase transition in Li3+2x(Sc1-xMgx)(2)(PO4)(3) and Li3-2x(Sc1-xMx)(2)(PO4)(2) (M = Ti, Zr, Sn, Kf) with x higher than 0.05, and in Li3-4x(Sc1-xMx)(2)(PO4)(3) (M=Nb, Ta) with x higher than 0.025. The room temperature ionic conductivity of Li3Sc2(PO4)(3) has been increased by three orders of magnitude with the highest conductivity observed in Li3-2x(Sc1-xTix)(2)(PO4)(3) with x = 0.20 and in Li3-2x(Sc1-xZrx)(2)(PO4)(3) with x = 0.10. It was ascribed to the stabilization of the high temperature superionic conduction phase and the introduction of vacancies on the Li+ sites by substituting Ti4+ Or Zr4+ for Sc3+.

    DOI: 10.1016/S0167-2738(97)00404-9

    Web of Science

    researchmap

  • Structure determination of new layered perovskite compound, NaLaTa2O7, synthesized by ion-exchange reaction Reviewed

    K Toda, K Uematsu, M Sato

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   105 ( 6 )   482 - 485   1997.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    A new layered perovskite compound, NaLaTa2O7, was synthesized by ion-exchange reaction of the rubidium compound, RbLaTa2O7. The crystal structure of the compound was determined by the Rietveld analysis for powder X-ray diffraction pattern. The crystal structure is analogous to that of the corresponding niobate compound, NaLaNb2O7. This layered perovskite compound is a new member of the Dion-Jacobson series with n=2 for the general formula M[A(n-1)B(n)O(3n+1)] (M=alkali metals).

    DOI: 10.2109/jcersj.105.482

    Web of Science

    researchmap

  • Synthesis and properties of lithium ion conductors Li3-2x(Sc1-xZrx)2(PO4)3 Reviewed

    Mineo Sato, Takahito Suzuki, Kenji Yoshida, Kazuyoshi Uematsu, Kenji Toda, Zuo Guang Ye

    Journal of Alloys and Compounds   250 ( 1 )   510 - 514   1997

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier Science S.A.  

    Lithium ion conductors, Li3-2x(Sc1-xZrx)2(PO4) (0qqxqq0.3), were prepared by a solid-state reaction. TG-DTA analysis indicated no phase transition in the samples with x superior to 0.05. X-ray powder diffraction analysis of these samples clearly showed the stabilization of a superionic conduction phase at room temperature with an orthorhombic system Pbcn. The highest conductivity was observed for the sample with x = 0.05, and ascribed to the stabilization of the superionic conduction phase and the introduction of vacancies on the Li+ sites by substituting Zr4+ for Sc3+.

    DOI: 10.1016/S0925-8388(96)02746-6

    Scopus

    researchmap

  • Unusual concentration quenching of europium luminescence in new layered perovskite compound, RbLa1-xEuxTa2O7 (0 ≤ x ≤ 1) Reviewed

    Kenji Toda, Toshihiko Honma, Mineo Sato

    Journal of Luminescence   71 ( 1 )   71 - 75   1997

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier  

    Dependence of emission intensity on Eu3+ concentration in new layered perovskite compound, RbLa1-xEuxTa2O7, with a perfect two-dimensional arrangement of luminescence center was studied. Critical value for concentration quenching is x = 0.5 for RbLa1-xEuxTa2O7. The critical concentration of this compound is discussed in terms of the crystal structure determined by the powder X-ray diffraction pattern using the Rietveld method. The concentration quenching found in this compound can be explained by means of a percolation model with two-dimensional interactions between Eu3+ sites in the host lattice.

    DOI: 10.1016/S0022-2313(96)00097-X

    Scopus

    researchmap

  • Synthesis and structure determination of new layered perovskite compound, KLaTa2O7 Reviewed

    Kenji Toda, Toshihiko Honma, Zuo Guang Ye, Mineo Sato

    Journal of Alloys and Compounds   249 ( 1 )   256 - 259   1997

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier Science S.A.  

    A new layered perovskite compound, KLaTa2O7, was synthesized by ion-exchange reaction from the rubidium compound. RbLaTa2O7. The crystal structure of KLaTa2O7 was determined by Rietveld analysis from powder X-ray diffraction patterns. It is analogous to the structure of the corresponding niobate compound. This layered perovskite compound is a new member of the Dion-Jacobson series with n = 2 for the general formula A[Mn-1BnO3n+1] (A = monovalent cations, B = Nb or Ta). The structural features of KLaTa2O7 are discussed by comparison with other compounds of the ALaTa2O7 family and the titanate compounds.

    DOI: 10.1016/S0925-8388(96)02752-1

    Scopus

    researchmap

  • Preparation of high lithium ion conducting LiLnSiO(4) (Ln=La,Sm) thin films by sol-gel method Reviewed

    M Sato, H Ueda, Y Ohara, K Uematsu, K Toda

    CHEMISTRY LETTERS   ( 7 )   657 - 658   1997

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CHEMICAL SOC JAPAN  

    A soi-gel method was applied to prepare thin films of LiLnSiO(4) (Ln=La,Sm). The coating solution was made from lithium isopropoxide, silicon tetraethoxide, and tris(acetylacetonato)rare-earth. Well crystalline films with 0.1 similar to 0.3 mu m in thickness were obtained on alumina and quartz glass substrates by spin-coating, followed by firing over 400 degrees C. The lithium ionic conductivity of the films was much greater than that of sintered samples prepared by a conventional solid state reaction at 1000 degrees C.

    DOI: 10.1246/cl.1997.657

    Web of Science

    researchmap

  • Synthesis and Ionic conductivity of New Layered Perovskite Compound, Ag2La2Ti3O10 Reviewed

    K. Toda, J. Watanabe, M. Sato

    Solid State Ionics   90   15 - 19   1996.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/S0167-2738(96)00373-6

    researchmap

  • Synthesis and high ionic conductivity of new layered perovskite compounds, AgLaTa2O7 and AgCa2Ta3O10 Reviewed

    K Toda, T Suzuki, M Sato

    SOLID STATE IONICS   93 ( 1-2 )   177 - 181   1996.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    New layered perovskite compounds, AgLaTa2O7 and AgCa2Ta3O10, have been synthesized by an ion-exchange reaction from parent compounds, RbLaTa2O7 and RbCa2Ta3O10. The crystal structures of silver ion-exchanged compounds were determined by the Rietveld analysis for powder XRD patterns. These compounds, which are probably metastable, could only be obtained by the ion-exchange reaction. The relatively high ionic conductivities attributed to the interlayer silver ions were observed at high temperatures.

    DOI: 10.1016/S0167-2738(96)00518-8

    Web of Science

    researchmap

  • Bulk and grain boundary ionic conduction in lithium rare earth silicates "LiLnSiO4" (Ln = La, Nd, Sm, Eu, Gd, Dy) Reviewed

    M. Sato, Y. Kono, H. Ueda, K. Uematsu, K. Toda

    Solid State Ionics   83   249 - 256   1996.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/0167-2738(95)00240-5

    researchmap

  • Crystal structure determination and ionic conductivity of layered perovskite compounds NaLnTiO4 (Ln = rare earth) Reviewed

    Kenji Toda, Yutaka Kameo, Satoru Kurita, Mineo Sato

    Journal of Alloys and Compounds   234 ( 1 )   19 - 25   1996.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    The layered perovskite compounds NaLnTiO4 (Ln = La, Pr, Nd, Sm, Eu, Gd, Y and Lu) were synthesized by the solid state reaction. The crystal structure of these compounds were determined by the Rietveld analysis. Single phases of the compounds (except for Ln = Lu) could be prepared only under very restricted preparation conditions. The composition of NaLuTiO4 was not a single phase under the conditions employed in this study. Compounds NaLnTiO4 have a tetragonal symmetry for Ln = La-Nd, while an orthorhombic symmetry is observed for Ln = Sm-Lu. The stabilization of NaLnTiO4 is discussed on the basis of the relative sizes of the rare earth and the alkali metal ions. The lowering of the symmetry is considered to be introduced by the mismatch between TiO2 and LnO2 layers. Ionic conductivities attributed to the interlayer sodium ions were observed at high temperatures. The magnitude of ionic conductivity of NaLaTiO4, with a single perovskite layer, was much higher than that of Na2La2Ti3O10, with a triple perovskite layer. This high ionic conductivity is due to the weak interaction between the perovskite layer and interlayer sodium ions.

    DOI: 10.1016/0925-8388(95)01969-3

    Scopus

    researchmap

  • New layered perovskite compounds, LiLaTiO4 and LiEuTiO4 Reviewed

    K Toda, S Kurita, M Sato

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   104 ( 2 )   140 - 142   1996.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    New layered perovskite compounds, LiLnTiO(4) (Ln=La and Eu), have been synthesized by an ion-exchange reaction from parent sodium compounds, NaLnTiO(4). The crystal structures of LiLaTiO4 and LiEuTiO4 were determined by Rietveld analysis of the powder X-ray diffraction (XRD) patterns. The lithium ion-exchanged compounds retain the crystal symmetry of the parent phases. Although the framework of the perovskite layer of these compounds is the same as that of the parent compounds, there exists a fundamental difference. The lithium ions within the interlayer have a tetrahedral coordination because of small ionic radius for a rock-salt coordination. The structure of LiLaTiO4 and LiEuTiO4 consist of intergrowths of the perovskite sheets with the layers of Li-O in a tetrahedral coordination and those of Ln-O in a distorted rock-salt coordination. These compounds exhibit new phases analogous to the Ruddlesden-Popper phase.

    DOI: 10.2109/jcersj.104.140

    Web of Science

    researchmap

  • Intercalation of water in a layered perovskite compound, NaEuTiO4 Reviewed

    Kenji Toda, Yutaka Kameo, Satoru Kurita, Mineo Sato

    Bulletin of the Chemical Society of Japan   69 ( 2 )   349 - 352   1996

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Chemical Society of Japan  

    Intercalation of water was observed in a layered perovskite compound, NaEuTiO4, leading to its hydrated derivatives. There are some metastable intermediates in the hydrated derivatives. The hydration process includes several steps that are topotactic. The crystal structure of the hydrated derivatives was identified by Rietveld analysis for the powder X-ray diffraction pattern. It is confirmed that the water molecules are inserted into the sodium layer of NaEuTiO4.

    DOI: 10.1246/bcsj.69.349

    Scopus

    researchmap

  • Crystal structure determination of ion-exchangeable layered perovskite compounds, K2La2Ti3O10 and Li2La2Ti3O10 Reviewed

    Kenji Toda, Jun Watanabe, Mineo Sato

    Materials Research Bulletin   31 ( 11 )   1427 - 1435   1996

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier Ltd  

    The crystal structure of the ion-exchangeable layered perovskite compounds K2La2Ti3O10 and Li2La2Ti3O10 were determined by Rietveld analysis for the powder X-ray diffraction pattern. Although the framework of the perovskite layer of lithium compound is the same as those of the corresponding sodium and potassium compounds, a fundamental difference exists. The lithium ions within the interlayer have a tetrahedral coordination because the ionic radius is too small for a rock-salt coordination. The layered perovskite compound Li2La2Ti3O10 exhibits a new phase analogous to the Ruddlesden-Popper phase.

    DOI: 10.1016/0025-5408(96)00135-3

    Scopus

    researchmap

  • Synthesis and structure determination of new layered perovskite compounds, ALaTa2O7 and ACa2Ta3O10 (A = Rb, Li) Reviewed

    Kenji Toda, Mineo Sato

    Journal of Materials Chemistry   6 ( 6 )   1067 - 1071   1996

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Royal Society of Chemistry  

    New layered perovskite compounds of RbLaTa2O7 and RbCa2Ta3O10, whose Rb+ ions can be ion-exchanged have been synthesized directly by a solid-state reaction. Lithium ion-exchanged compounds, LiLaTa2O7 and LiCa2Ta3O10, have also been synthesized by ion-exchange reactions of the rubidium compounds with LiNO3 molten salt. The crystal structures of these compounds have been determined by Rietveld analysis of their powder X-ray diffraction patterns. The crystal structures of these compounds are analogous to those of the corresponding niobate compounds. These compounds are new members of the Diori-Jacobson series with the general formula A[Mn-1BnO3n+i] (A = alkali metal), with n = 2 and 3.

    DOI: 10.1039/jm9960601067

    Scopus

    researchmap

  • Synthesis and ionic conductivity of novel layered perovskite compounds, AgLaTiO4 and AgEuTiO4 Reviewed

    Kenji Toda, Satoru Kurita, Mineo Sato

    Solid State Ionics   81 ( 3-4 )   267 - 271   1995.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Novel compounds, AgLaTiO4 and AgEuTiO4, have been synthesized by an ion-exchange reaction from parent compounds, NaLaTiO4 and NaEuTiO4. The crystal structure of the silver ion-exchanged compounds was determined by the Rietveld analysis for powder XRD patterns. The silver ion-exchange compounds retain the structural characteristics of the parent phases. The interlayer silver ions in the silver ion-exchanged compounds have a rock-salt type coordination. These compounds, which are probably metastable, could only be obtained by the ion-exchange reaction. The ionic conductivities attributed to the interlayer silver ions were observed at high temperatures. The ionic conductivity of AgLaTiO4 was much higher than that of NaLaTiO4. Such a high ionic conductivity is probably due to the higher polarizability of silver ion. © 1995.

    DOI: 10.1016/0167-2738(95)00184-8

    Scopus

    researchmap

  • Luminescence properties of layered perovskites activated by Eu3+ ions Reviewed

    Kenji Toda, Yutaka Kameo, Masatoshi Ohta, Mineo Sato

    Journal of Alloys and Compounds   218 ( 2 )   228 - 232   1995.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Dependence of emission intensity on Eu3+ concentration in Na2Gd2(1-x)Eu2xTi3O10 with a triple perovskite layer and NaGd1-xEuxTiO4 with a single perovskite layer was studied. Critical values for concentration quenching are x = 0.40 for Na2Gd2(1-x)Eu2xTi3O10 and x = 0.25 for NaGd1-xEuxTiO4. The difference in the critical concentration between both compounds is discussed in terms of their crystal structures determined by the powder X-ray diffraction patterns using the Rietveld method. The concentration quenching found in these compounds can be explained by means of a percolation model with nearly two-dimensional interactions between Eu3+ sites in the host lattice. © 1995.

    DOI: 10.1016/0925-8388(94)01395-0

    Scopus

    researchmap

  • Crystal structure and ionic conductivity of a layered perovskite, Na2La2Ti3O10 Reviewed

    Kenji Toda, Yutaka Kameo, Masayuki Fujimoto, Mineo Sato

    Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan   102   737 - 741   1994

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Ceramic Soc of Japan  

    An ion-exchangeable layered perovskite compound, Na2La2Ti3O10, was directly synthesized by a solid-state reaction. The crystal structure of Na2La2Ti3O10 was determined by electron diffraction analysis and Rietveld analysis for the powder X-ray diffraction pattern. The unit cell is tetragonal with a = 0.383528(7) nm, c = 2.85737(7) nm and Z = 2 with the space group I4/mmm (No. 139). The structure of this compound is analogous to that of the Ruddlesden-Popper phases. The ionic conductivity of Na2La2Ti3O10 was not very high compared with those of niobate compounds, NaLaNb2O7 and NaCa2NaNb4O13. Such a low ionic conductivity is due to the rigid rock-salt-type coordination around sodium ions located at the interlayer.

    DOI: 10.2109/jcersj.102.737

    Scopus

    researchmap

  • 層状ペロブスカイトK2La2Ti3O10およびその銀イオン交換体の構造とイオン伝導性 Reviewed

    佐藤峰夫, 戸田健司, 渡辺潤, 上松和義

    日本化学会誌   5   640 - 646   1993.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1246/nikkashi.1993.640

    researchmap

▶ display all

Books

  • 全固体電池のイオン伝導性向上技術と 材料、製造プロセスの開発[フッ化バナジウム(III)を用いたLiイオン二次電池用正極材料の合成技術と特性評価]

    板谷 篤志, 戸田 健司, 佐藤 峰夫( Role: Joint author)

    技術情報協会  2017.2  ( ISBN:9784861046476

     More details

    Total pages:1-464   Responsible for pages:237-242   Language:Japanese Book type:Scholarly book

    researchmap

  • Phosphors, Up Conversion Nano Particles, Quantum Dots and Their Applications: Volume 1

    S-W. Kim, K. Toda, T. Hasegawa, K. Uematsu, M. Sato( Role: Contributor)

    Springer-Verlag Berlin Heidelberg  2016.10  ( ISBN:9783662527719

     More details

    Total pages:1-593   Responsible for pages:219-246   Language:English Book type:Scholarly book

    researchmap

  • Rare Earth-Doped Phosphors for White Light-Emitting Diodes

    M. Sato, S.W. Kim, Y. Shimomura, T. Hasegawa, K. Toda, G. Adachi( Role: Joint author)

    Elsevier B.V.  2016.6 

     More details

    Total pages:1-128   Language:English Book type:Scholarly book

    researchmap

  • 蓄・省エネルギー材料の開発における機能性付与技術[LEDの演色性と色再現性を高める蛍光体](共著)

    戸田健司, 佐藤峰夫, 上松和義, 石垣雅, 亀井真之介( Role: Joint translator)

    技術情報協会  2012.5 

     More details

    Language:Japanese Book type:Scholarly book

    researchmap

  • レアアースの最新技術動向と資源戦略[希土類フリー蛍光体の開発動向](共著)

    戸田健司, 亀井真之介, 石垣雅, 上松和義, 佐藤峰夫( Role: Joint author)

    シーエムシー出版  2011.12 

     More details

    Language:Japanese Book type:Scholarly book

    researchmap

  • レアメタル・レアアースの代替材料開発[希土類を含まない蛍光体材料の開発動向] (共著)

    戸田健司( Role: Joint author ,  第9節 希土類を含まない蛍光体材料の開発動向(257-268))

    技術情報協会  2011.7 

     More details

    Language:Japanese Book type:Scholarly book

    researchmap

  • 発光・照明材料[希土類を含まない蛍光体材料]

    戸田健司( Role: Joint author ,  182-193)

    日刊工業新聞社  2010.12  ( ISBN:9784526065743

     More details

    Language:Japanese Book type:Scholarly book

    researchmap

  • LED照明の高効率化プロセス・材料技術と応用展開[LED用蛍光体材料の合成・設計・結晶構造と高効率化](共著)

    戸田健司, 石垣雅, 上松和義, 佐藤峰夫( Role: Joint author ,  129-141)

    サイエンス&テクノロジー株式会社  2010.5  ( ISBN:9784903413884

     More details

    Language:Japanese Book type:Scholarly book

    researchmap

  • WEEE/RoHS、ELV、REACHの要求事項に対応した有害元素分析と代替技術[水銀の代替技術](共著)

    戸田健司( Role: Joint author ,  291-299)

    技術情報協会  2008.6 

     More details

    Language:Japanese

    researchmap

  • ラボレベル・研究初期で必要となる発光素子、発光デバイス開発のための基礎技術・装置・測定、評価法[ケミカル、光物理から見た蛍光体の発光とその評価](共著)

    戸田健司( Role: Joint author ,  3-18)

    情報機構  2008.3 

     More details

    Language:Japanese

    researchmap

  • Handbook of advanced dielectric, piezoelectric and ferroelectric materials: Synthesis, properties and applications"Room temperature preparation of KNbO3 nanoparticle and thin film from a perovskite nanosheet"(共著)

    Kenji Toda, Mineo sato( Role: Joint author ,  884-895)

    Woodhead Publishing Limited  2008.3 

     More details

    Language:English Book type:Scholarly book

    researchmap

  • デジタル画像における色再現・質感表現技術[高演色化に向けたLED蛍光体材料](共著)

    戸田健司( Role: Joint author ,  291-307)

    技術情報協会  2007.12 

     More details

    Language:Japanese

    researchmap

  • 最新LED部材の開発[白色LED用蛍光体の発光特性と製造方法](共著)

    戸田健司( Role: Joint author ,  163-187)

    技術情報協会  2007.4 

     More details

    Language:Japanese

    researchmap

  • 現代無機材料科学[表示・ディスプレイと照明のための材料発光と蛍光](共著)

    戸田健司( Role: Joint author ,  59-74)

    化学同人  2007.1 

     More details

    Language:Japanese

    researchmap

  • ナノパーティクルテクノロジーハンドブック[光学的特性](共著)

    戸田健司( Role: Joint author ,  436-439)

    日刊工業新聞社  2006.4  ( ISBN:4526056642

     More details

    Language:Japanese

    researchmap

  • ナノパーティクルテクノロジーハンドブック[新規蛍光体の開発](共著)

    戸田健司( Role: Joint author ,  353-355)

    日刊工業新聞社  2006.4  ( ISBN:4526056642

     More details

    Language:Japanese

    researchmap

  • ナノパーティクルテクノロジーハンドブック[光透過性](共著)

    戸田健司( Role: Joint author ,  42-45)

    日刊工業新聞社  2006.4  ( ISBN:4526056642

     More details

    Language:Japanese

    researchmap

  • 高輝度LED材料のはなし[白色LED用蛍光体」(共著)

    戸田健司( Role: Joint author ,  102-125)

    日刊工業新聞社  2005.12  ( ISBN:4526055573

     More details

    Language:Japanese

    researchmap

  • 蛍光体の基礎及び用途別最新動向[蛍光灯・水銀灯用蛍光体](共著)

    戸田健司( Role: Sole author ,  135-144)

    株式会社情報機構  2005.11  ( ISBN:4901677462

     More details

    Language:Japanese

    researchmap

  • 光触媒 基礎・材料開発・応用[タンタル系層状ペロブスカイト酸化物光触媒による水の完全分解反応](共著)

    戸田健司, 佐藤峰夫( Role: Joint author ,  332-336)

    エヌ・ティー・エス  2005.5 

     More details

    Language:Japanese Book type:Scholarly book

    researchmap

▶ display all

MISC

  • 蛍光体の合成プロセス Invited Reviewed

    長谷川 拓哉, 戸田 健司, 金 善旭, 佐藤 峰夫

    スマートプロセス学会誌   5 ( 6 )   350 - 357   2016.11

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

    researchmap

  • 蛍光体の劣化 Invited Reviewed

    金 善旭, 長谷川 拓哉, 戸田 健司, 佐藤 峰夫

    Journal of the Society of Inorganic Materials, Japan   23 ( 11 )   416 - 421   2016.11

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

    researchmap

  • Synthesis of High Purity Nitride Phosphor Using a VESTA Vacuum-Pressure Sintering Furnace Invited Reviewed

    73 ( 1-2 )   89 - 95   2016.9

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (other)  

    CiNii Article

    CiNii Books

    researchmap

  • 新規リン酸塩蛍光体の探索,開発および展開 Invited Reviewed

    長谷川 拓哉, 金 善旭, 戸田 健司, 佐藤 峰夫

    Phosphorus Letters   86 ( 6 )   55 - 68   2016.6

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

    researchmap

  • 将来,LEDにはどんな蛍光体が必要になるのか? -要求特性と開発動向- Invited

    戸田 健司, 金 善旭, 石垣 雅, 亀井 真之介, 長谷川 拓哉, 上松 和義, 佐藤 峰夫

    MATERIAL STAGE   15 ( 3 )   44 - 50   2015

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

    researchmap

  • 白色LED用蛍光体の現状と課題 Invited

    戸田 健司, 金 善旭, 石垣 雅, 亀井 真之介, 長谷川 拓哉, 上松 和義, 佐藤 峰夫

    セラミックス   50 ( 3 )   144 - 155   2015

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

    researchmap

  • 白色LED用蛍光体 Invited

    戸田 健司, 金 善旭, 上松 和義, 佐藤 峰夫

    光技術動向調査報告書   62 - 67   2014.3

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (other)   Publisher:一般財団法人光産業技術振興協会  

    researchmap

  • LED向け蛍光体の開発動向 Invited

    金 善旭, 戸田 健司, 石垣 雅, 上松 和義, 佐藤 峰夫

    鉱山   66 ( 6 )   37 - 45   2013.7

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (other)   Publisher:金属鉱山会  

    researchmap

  • 希土類蛍光体 Invited

    戸田 健司

    日本機械学会 機械材料・材料加工部門ニュースレター   44   19 - 21   2012.11

     More details

    Language:Japanese   Publishing type:Internal/External technical report, pre-print, etc.   Publisher:日本機械学会 機械材料・材料加工部門  

    researchmap

  • LED用蛍光体の現状と課題

    戸田健司

    電気化学および工業物理化学   79 ( 9 )   711 - 715   2011.9

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:社団法人電気化学会  

    DOI: 10.5796/electrochemistry.79.711

    CiNii Article

    CiNii Books

    researchmap

    Other Link: https://jlc.jst.go.jp/DN/JALC/00377193374?from=CiNii

  • LED照明用蛍光体の開発 Invited

    石垣 雅, 戸田 健司, 佐藤 峰夫

    MRS-J NEWS   23 ( 2 )   2 - 3   2011.5

     More details

    Language:Japanese   Publishing type:Internal/External technical report, pre-print, etc.  

    researchmap

  • 無機発光材料の開発動向

    戸田健司, 石垣雅, 上松和義, 佐藤峰夫

    工業材料   59 ( 4 )   34 - 38   2011.3

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)   Publisher:日刊工業新聞社  

    researchmap

  • 変換効率の高い新しい蛍光体の開発トレンド

    戸田健司, 石垣雅, 上松和義, 佐藤峰夫

    マテリアルステージ   10   61 - 65   2010.4

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:技術情報協会  

    researchmap

  • ナノ粒子蛍光体

    石垣雅, 戸田健司, 上松和義, 佐藤峰夫

    セラミックス   45 ( 2 )   109 - 112   2010.2

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (other)   Publisher:日本セラミックス協会  

    researchmap

  • 白色LED用蛍光体

    戸田健司

    光学   38 ( 3 )   132 - 137   2009.3

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:日本光学会(応用物理学会)  

    researchmap

  • 照明およびディスプレイ用蛍光体の現状と将来

    戸田健司

    計量計測 はかる   25 ( 1 )   12 - 15   2008.8

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (other)   Publisher:社団法人日本計量機器工業連合会  

    researchmap

  • Transparency of nanoparticle

    K.Toda

    Nanoparticle Technology Handbook   372 - 374   2007.12

     More details

    Language:English   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:Elsevier  

    researchmap

  • Optical property of nanoparticle

    K.Toda

    Nanoparticle Technology Handbook   45 - 48   2007.12

     More details

    Language:English   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:Elsevier  

    researchmap

  • Development of New phosphors

    K.Toda

    Nanoparticle Technology Handbook   464 - 467   2007.12

     More details

    Language:English   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:Elsevier  

    DOI: 10.1016/B978-0-444-56336-1.50024-2

    researchmap

  • 次世代照明における蛍光体

    戸田健司, 佐藤峰夫

    月刊ディスプレイ   13 ( 11 )   19 - 23   2007.11

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:㈱テクノタイムス゛  

    researchmap

  • 新規な希土類蛍光体の開発

    戸田健司

    化学工業   58 ( 10 )   31 - 35   2007.10

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:化学工業社  

    researchmap

  • 白色LED用蛍光体の発光特性と製造方法

    戸田健司

    最新LED部材の開発   163 - 187   2007.4

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:技術情報協会  

    researchmap

  • 水分解光触媒の結晶化学と光触媒活性の相関

    戸田健司

    会報光触媒   92 - 99   2007.4

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:光機能材料研究会  

    researchmap

  • Low temperature crystallization of titanium oxide

    38 ( 1 )   14 - 18   2007.4

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

    CiNii Article

    CiNii Books

    researchmap

  • 表示・ディスプレイと照明のための材料-発光と蛍光

    戸田健司

    現代無機材料科学   59 - 74   2007.1

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:化学同人  

    researchmap

  • 次世代照明用の新規な蛍光体材料の開発

    戸田健司

    ケミカルエンジニヤリング   52 ( 1 )   37 - 42   2007.1

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:化学工業社  

    researchmap

  • 蛍光体の夢と現実

    戸田健司

    工業材料   54 ( 12 )   863 - 867   2006.11

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:日刊工業新聞社  

    researchmap

  • アスベスト関連物質を原料とする蛍光体の合成

    戸田健司, 白倉重樹, 上松和, 義佐藤峰夫

    日本セラミックス協会   41 ( 10 )   863 - 867   2006.10

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:セラミックス誌  

    researchmap

  • 室温でのペロブスカイトナノシートからのKNbO3ナノ粒子および薄膜の作成

    戸田健司, 佐藤峰夫

    マテリアルインテグレーション   19 ( 9 )   33 - 38   2006.8

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:マテリアルインテグレーション  

    researchmap

  • 次世代照明における蛍光体

    戸田健司

    セラミックス誌   41 ( 8 )   607 - 611   2006.8

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:日本セラミックス協会  

    researchmap

  • 未来を照らす希土類蛍光体

    戸田健司, 増井敏行, 今中信人

    マテリアルインテグレーション   19 ( 1 )   31 - 38   2005.12

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:マテリアルインテグレーション  

    researchmap

  • LED蛍光体の発光特性とLEDへの応用

    戸田健司

    マテリアルステージ   5 ( 6 )   1 - 6   2005.9

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:マテリアルステージ  

    researchmap

  • 水銀フリーランプ用の新しい蛍光体の開発

    戸田健司

    マテリアルインテグレーション   17 ( 3 )   15 - 20   2004.2

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:マテリアルインテグレーション  

    researchmap

  • Luminescence Property of Layered Perovskite Compounds

    TODA Kenji, SATO Mineo

    Ceramics Japan   31 ( 5 )   422 - 425   1996.5

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

    CiNii Article

    CiNii Books

    researchmap

▶ display all

Presentations

  • (国際会議)(招待講演)New raw material “SiO” for the synthesis of silicate phosphors International conference

    Kenji Toda

    Phosphor Safari 2010  2010.11 

     More details

    Language:English   Presentation type:Oral presentation (invited, special)  

    researchmap

  • (国内会議)ナノクリスタル蛍光体の新展開

    戸田健司

    2010 年セラミックス協会年会サテライトプログラム 第7回ナノクリスタルセラミックス研究会  2010.3 

     More details

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    researchmap

  • (国際会議)(招待講演)New vanadate-phosphate phosphors for lighting application International conference

    Kenji Toda

    9th International Meeting on Information Display  2009.10 

     More details

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:ソウル(韓国)  

    researchmap

  • (国際会議)Room temperature synthesis of vanadate luminescent materials International conference

    K. Toda, A. Toda, T. Ishigaki, K. Uematsu, M. Sato

    8Th PACIFIC RIM CONFERENCE ON CERAMIC AND GLASS TECHNOLOGY  2009.6 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:バンクーバー  

    researchmap

  • (国際会議)Hydrothermal Reaction by Microwave Heating for Synthesis of LiFePO4 as Cathode Material International conference

    C. Sato, E. Hoshi, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    The IUMRS International Conference in Asia 2008  2008.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:名古屋  

    researchmap

  • (国際会議)Preparation and Optical Characterization of blue emission phosphate phosphor LiSrPO4:Eu2+ for white LEDs International conference

    T. Ishigaki, T. Hatsumori, K. Uematsu, K. Toda, M. Sato

    The 15th International Display Workshops  2008.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Synthesis and properties of metal organic framework compounds containing Eu and Tb International conference

    Y. Sato, Z. Taoyun, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    The IUMRS International Conference in Asia 2008  2008.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:名古屋  

    researchmap

  • (国際会議)(招待講演)Possibility of highly efficient luminescence in morphology controlled phosphor materials International conference

    Kenji Toda

    2008 KACG Fall Meeting  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:ソウル(韓国)  

    researchmap

  • (国際会議)(招待講演)Crystal Chemistry and Morphology Control for Phosphor Materials International conference

    Kenji Toda

    SAINT Symposium 2008  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:水原(韓国)  

    researchmap

  • (国際会議)New Titanium Oxide Compound for photocatalytic water spliting International conference

    S.Nakajima, S.Watanabe, K.Uematsu, T.Ishigaki, K.Toda, M.Sato

    The 6th Asian Meeting on Electroceramics  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:つくば  

    researchmap

  • (国際会議)Development of New Red Phosphor Na3YSi2O7:Eu3+ for a white LED International conference

    S. Kousaka, K. Toda, T. Ishigaki, K. Uematsu, M. Sato

    The 6th Asian Meeting on Electroceramics  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:つくば  

    researchmap

  • (国際会議)Photocatalytic Activity of Bismuth Layered Perovskite Treated with Acid International conference

    S. Watanabe, Y. Narumi, K. Toda, T. Ihigaki, K. Uematsu, M. Sato

    The 6th Asian Meeting on Electroceramics  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:つくば  

    researchmap

  • (国際会議)Luminescence properties of Y(P,V)O4 synthesized by microwave heating International conference

    A. Toda, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    The 6th Asian Meeting on Electroceramics  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:つくば  

    researchmap

  • (国際会議)Synthesis and luminescence properties of non-doped long persistent phosphors: Mg2SnO4 International conference

    A. Torisaka, H. Kaneko, K. Nomizu, S. Abe, T. Ishigaki, K. Toda, K. Uematsu

    The 6th Asian Meeting on Electroceramics  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:つくば  

    researchmap

  • (国際会議)Novel Ba-Sc-Si-oxide and oxynitride phosphors for a white LED International conference

    T. Nakano, Y. Kawakami, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Pacific Rim Meeting on Electrochemical and Solid-state Science 2008  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議) New synthesis method of green emitting oxysulfate phosphor International conference

    M. Ohashi, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Pacific Rim Meeting on Electrochemical and Solid-state Science 2008  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Long persistence of rare earth doped Ca2SnO4 phosphors International conference

    T. Ishigaki, A. Torisaka, K. Nomizu, K. Uematsu, K. Toda, M. Sato

    Pacific Rim Meeting on Electrochemical and Solid-state Science 2008  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Synthesis of Eu3+ doped molybdate phosphors by microwave heating method International conference

    A. Toda, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Pacific Rim Meeting on Electrochemical and Solid-state Science 2008  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Luminescent Properties of two kinds of Newly Synthesized Metal Organic Frameworks (MOF’s) Containing International conference

    Z. Taoyun, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Pacific Rim Meeting on Electrochemical and Solid-state Science 2008  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Synthesis of phosphate phosphors for a white LED International conference

    K. Toda, T. Hatsumori, Ho Li Ngee, K. Uematsu, T. Ishigaki, M. Sato

    Pacific Rim Meeting on Electrochemical and Solid-state Science 2008  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Effects of selective leaching of bismuth oxide sheets in Sillen-Aurivillius phase on their photocatalytic activities International conference

    H. Hatakeyama, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    Pacific Rim Meeting on Electrochemical and Solid-state Science 2008  2008.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)UV and VUV luminescence property of YVO4:Eu3+ synthesized by microwave heating method International conference

    A. Toda, A. Ochiai, K. Uematsu, T. Ishigaki, K. Toda, Mineo Sato

    14th International Workshop on Inorganic and Organic Electroluminescence &2008 International Conference on the Science and Technology of Emissive Displays and Lighting  2008.9 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ティボリ(イタリア)  

    researchmap

  • (国際会議)New synthetic route of non-stoichiometric rare earth niobates using rubidium carbonate flux International conference

    S. Seki, Y. Kawakami, M. Hosoume, K. Uematsu, T. Ishigaki, K. Toda, Mineo Sato

    14th International Workshop on Inorganic and Organic Electroluminescence &2008 International Conference on the Science and Technology of Emissive Displays and Lighting  2008.9 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ティボリ(イタリア)  

    researchmap

  • (国際会議)Synthesis of nano-size blue phosphor, BaMgAl10O17:Eu2+, from the Flash Creation Method International conference

    K. Toda, K. Uematsu, T. Ishigaki, M. Sato, A. Watanabe, T. Fukui

    The 15th International conference on luminescence and optical spectroscopy of condensed matter  2008.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:リヨン(フランス)  

    researchmap

  • (国際会議)Synthesis of Y(V,P)O4:Eu3+ phosphors by microwave heating method International conference

    K. Uematsu, A. Toda, T. Ishigaki, K. Toda, M. Sato

    The 15th International conference on luminescence and optical spectroscopy of condensed matter  2008.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:リヨン(フランス)  

    researchmap

  • (国際会議)Melt synthesis of oxide red phosphors with La2WO6:Eu3+ International conference

    T. Ishigaki, N. Matsushita, K. Uematsu, M. Sato, K. Toda

    The 15th International conference on luminescence and optical spectroscopy of condensed matter  2008.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:リヨン(フランス)  

    researchmap

  • (国際会議)Novel Ba-Sc-Si-oxide and oxynitride phosphors for a white LED International conference

    T. Nakano, Y. Kawakami, A. Komeno, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    The 15th International conference on luminescence and optical spectroscopy of condensed matter  2008.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:リヨン(フランス)  

    researchmap

  • (国際会議) Synthesis of phosphate phosphor for a white LED International conference

    T. Hatsumori, Ho Li Ngee, K. Uematsu, T. Ishigaki, K. Toda, M. Sato

    The 15th International conference on luminescence and optical spectroscopy of condensed matter  2008.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:リヨン(フランス)  

    researchmap

  • (国際会議)UV and VUV luminescence properties of novel silicate phosphors International conference

    S. Seki, Y. Kawakami, M. Hosoume, K. Uematsu, T. Ishigaki, K. Toda, Mineo Sato

    The 15th International conference on luminescence and optical spectroscopy of condensed matter  2008.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:リヨン(フランス)  

    researchmap

  • (国際会議)Development of high luminance phosphor by morphology control International conference

    K. Sato, Y. Ito, M. Hosoume, S. Shirakura, S. kawada, A. Watanabe, T. Fukui, K. Uematsu, K. Toda, M. Sato

    First International Conference on White LEDs and Solid State Lighting  2007.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:東京  

    researchmap

  • (国際会議)Development of novel phosphors for a white LED International conference

    Y. Kawakami, A. Komeno, K. Uematsu, K. Toda, M. Sato

    First International Conference on White LEDs and Solid State Lighting  2007.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:東京  

    researchmap

  • (国際会議) Melt synthesis and characterization of LED phosphors International conference

    K. Toda, M. Hosoume, S. Shirakura, S. kawada, K. Uematsu, M. Sato, T. Ishigaki, M. Yoshimura

    First International Conference on White LEDs and Solid State Lighting  2007.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:東京  

    researchmap

  • (国際会議)Novel red phosphors for a white LED International conference

    S. Seki, Y. Ito, S. Kousaka, K. Uematsu, K. Toda, M. Sato

    First International Conference on White LEDs and Solid State Lighting  2007.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:東京  

    researchmap

  • (国際会議)Synthesis of Nano Phosphor using the Flash Creation Method International conference

    K. Toda, K. Uematsu, M. Sato, A. Watanabe, T. Fukui

    14th Asian Symposium on Ecotechnology  2007.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:水原(韓国)  

    researchmap

  • (国際会議)Synthesis of Potassium Niobate Nanoparticles and Thin Film from a Perovskite Nanosheet at Room Temperature International conference

    K. Toda, A. Iida, T. Takahashi, K. Uematsu, M. Sato

    ICE2007 (Internationla Conference on Electroceramics)  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:アルーシャ(タンザニア)  

    researchmap

  • (国際会議)Application of Layered Tantalum Oxides Nanosheet to Photocatalytic Reaction International conference

    Y. Mori, H. Kibe, K. Uematsu, K. Toda, M. Sato

    The 4th International Symposium on Advanced Materialsin Asia-Pacific Rim  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    researchmap

  • (国際会議) Photocatalytic Activity of Bismuth Layered Perovskite Treated with Acid International conference

    Y. Narumi, K. Uematsu, K. Toda, M. Sato

    The 4th International Symposium on Advanced Materials in Asia-Pacific Rim  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Deveropment of Novel Phosphor for a White LED International conference

    Y. Kawakami, A. Komeno, K. Uematsu, K. Toda, M. Sato

    The 4th International Symposium on Advanced Materialsin Asia-Pacific Rim  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Preparation of KNbO3 Thin Film at Room Temperature International conference

    T. Takahashi, K. Toda, K. Uematsu, M. Sato

    The 4th International Symposium on Advanced Materialsin Asia-Pacific Rim  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議) Low Temperature Synthesis of TiO International conference

    S. Seki, Y. Ito, K. Uematsu, K. Toda, M. Sato

    The 4th International Symposium on Advanced Materialsin Asia-Pacific Rim  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)New Photpcatalyst of Metal Oxides With d10 Configuration International conference

    H. Ishikawa, K. Uematsu, K. Toda, M. Sato

    ISAMAP 2007 in Niigata  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Melt Synthesis And Morphology Control of phosphor Materials International conference

    K. Toda, M. Hosoume, K. Uematsu, M. Sato, T. Ishigaki, M. Yoshimura

    ISAMAP 2007 in Niigata  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Low Temperature Synthesis of TiO2 International conference

    S. Nakajima, Y. Yamanaka, K. Uematsu, K. Toda, M. Sato

    ISAMAP 2007 in Niigata  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Removal of Fluorine From Waste Water by Ettringite International conference

    K. Sato, H. Morinaga, T. Tokumitsu, K. Uematsu, K. Toda, M. Sato

    ISAMAP 2007 in Niigata  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Low Temperature Growth of Potassium Niobate Single Crystal International conference

    A. Iida, K. Uematsu, K. Toda, M. Sato

    ISAMAP 2007 in Niigata  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Synthesis of nano-size blue phosphor, BaMgAl10O17:Eu2+, from the Flash Creation Method International conference

    K. Toda, K. Uematsu, T. Ishigaki, M. Sato, A. Watanabe, T. Fukui

    The 15th International conference on luminescence and optical spectroscopy of condensed matter  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:リヨン(フランス)  

    researchmap

  • (国際会議)Synthesis of Y(V,P)O4:Eu3+ phosphors by microwave heating method International conference

    K. Uematsu, A. Toda, T. Ishigaki, K. Toda, M. Sato

    The 15th International conference on luminescence and optical spectroscopy of condensed matter  2007.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:リヨン(フランス)  

    researchmap

  • (国際会議)Single Crystal Growth of KNbO3 at Low Temperature International conference

    K. Toda, A. Iida, T. Takahashi, K. Uematsu, M. Sato, Y. Noguchi, M. Miyayama

    The 16th IEEE International Symposium on the Applications of Ferroelectrics  2007.5 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:奈良  

    researchmap

  • (国際会議)Melt Synthesis and Characterization of Phosphor Materials International conference

    K. Toda, M. Hosoume, K. Uematsu, M. Sato, T. Ishigaki, M. Yoshimura

    1st International Coference on Science and Technology for Advanced Ceramics  2007.5 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:神奈川  

    researchmap

  • (国際会議)Removal Of Fluorine From Waste Water By Ettringite International conference

    S. Nakajima, Y. Yamanaka, K. Uematsu, K. Toda, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Low Temperature Growth Of Potassium Niobate Single Crystal International conference

    A. Iida, K. Uematsu, K. Toda, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Novel Red phosphor Ba2Gd3Li3Mo8O32:Eu3+ For A LED Application International conference

    S. Seki, Y. Ito, K. Uematsu, K. Toda, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Photocatalytic Activity Of La2BaIn2O7 International conference

    H. Ishikawa, K. Uematsu, K. Toda, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Low Temperature Synthesis Of TiO2 International conference

    K. Toda, S. Seki, Y. Ito, K. Uematsu, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata新潟  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Synthesis And Photocatalytic Property Of New Tantalate International conference

    H. Kibe, Y. Mori, K. Uematsu, K. Toda, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Photocatalytic Activity Of Bismuth Layered Perovskite Treated With Acid International conference

    Y. Narumi, K. Uematsu, K. Toda, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Application Of Layered Tantalum Oxides Nanosheet To Photocatalytic Reaction International conference

    Y. Mori, H. Kibe, K. Uematsu, K. Toda, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Room Temperature Preparation Of KNbO3 Nanoparticles Thin Film International conference

    K. Toda, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Photocatalytic Activity Of Barium Tantalum Oxynitride International conference

    T. Matsumoto, K. Uematsu, K. Toda, M. Sato

    nternational Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Preparation of KNbO3 Thin Film at Room Temperature International conference

    T. Takahashi, K. Toda, K. Uematsu, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)Deveropment Of Novel Phosphor For A White LED International conference

    Y. Kawakami, A. Komeno, K. Uematsu, K. Toda, M. Sato

    International Symposium on Fusion Technology 2006-2007 at Niigata  2007.1 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:新潟  

    researchmap

  • (国際会議)New Red LED Phosphor, Ba2R3Li3M8O32:Eu(R = Rare earths, M = Mo and W) International conference

    K. Toda, S. Seki, Y. Ito, K. Uematsu, M. Sato

    The 13th International Display Workshops  2006.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:大津  

    researchmap

  • (国際会議)Low Temperature Growth of Potassium Niobate Single Crystal International conference

    A. Iida, T. Takahashi, K. Toda, K. Uematsu, M. Sato

    13th Asian Symposium on Ecotechnology  2006.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:富山  

    researchmap

  • (国際会議)Removal of Fluorine from Waste Water by Calcium Aluminates International conference

    K. Sato, H. Morinaga, T. Tokumitsu, K. Toda, S. Kawada, S. Shirakura, K. Uematsu, M. Sato

    13th Asian Symposium on Ecotechnology  2006.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:富山  

    researchmap

  • (国際会議)New Phosphors for Mercury-free Lighting International conference

    K. Toda, Y. Imanari, S. Kawada, S. Shirakura, Y. Kawakami, S. Kousaka, K. Uematsu, M. Sato

    13th Asian Symposium on Ecotechnology  2006.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:富山  

    researchmap

  • (国際会議)(招待講演)Low temperature growth of potassium niobate single crystal International conference

    Kenji Toda

    2006 KACG Fall Meeting  2006.11 

     More details

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:仁川(韓国)  

    researchmap

  • (国際会議)Low temperature growth of potassium niobate single crystal International conference

    K. Toda

    2006 KACG Fall Meeting  2006.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:インチョン  

    researchmap

  • (国際会議)Intelligent synthetic method for inorganic materials with microwave heating International conference

    M. Sato, K. Toda, K. Uematsu, A. Ochiai

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Synthesis and Luminescence Properties of New LED Yellow Phosphor Li2SrSiO4:Eu2+ International conference

    Y. Ito, M. Kawamoto, K. Uematsu, K. Toda, M. Sato

    The 12th International Display Workshops in conjuction with Asia Display 2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:高松  

    researchmap

  • (国際会議)Photocatalytic activity of barium tantalum oxynitride International conference

    T. Matsumoto, M. Sato, K. Uematsu, K. Toda

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)New Silicate Phosphors for White LED International conference

    K. Toda, Y. Kawakami, S. Kousaka, Y. Ito, A. Komeno, K. Uematsu, M. Sato

    The 12th International Display Workshops in conjuction with Asia Display 2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:高松  

    researchmap

  • (国際会議)Colloid chemistry of oxyfluoride niobate International conference

    K. Toda, S. Kawada, A. Sugawara, K. Uematsu, M. Sato

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Characterization of alkarine earth silicate phosphor, Ba2MgSi2O7:Eu2+ International conference

    A. Komeno, K. Uematsu, K. Toda, M. Sato

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Luminescence properties of Eu2+-activated Li2SrSiO4 as novel LED yellow phosphor International conference

    Y. Ito, M. Kawamoto, K. Uematsu, K. Toda, M. Sato

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Fluidized-bed reaction of Ta2O5 powder with N2-NH3-C6H14 gas mixture International conference

    K. Hashimoto, H. Seyama, A. Ozaki, M. Oguri, K. Toda, N. Hotta

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Synthesis of flake-like TiN powder by floating-type reduction-nitridation International conference

    S. Suzuki, C. Someya, N. Saito, D. Takatashi, K. Toda, N. Hotta

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)New layered perovskite oxynitride photocatalyst International conference

    K. Toda, H. Sato, S. Kawada, K. Uematsu, M. Sato

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Synthesis and photocatalytic property of new tantalate International conference

    H. Kibe, K. Toda, M. Sato, K. Uematsu

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Development of long afterglow UV emission phosphors International conference

    M. Hosoume, K. Toda, K. Uematsu, M. Sato

    Pacifichem2005  2005.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)(招待講演)Research and Development of New Long Afterglow Silicate Phosphors International conference

    Kenji Toda, Kazuyoshi Uematsu, Mineo Sato

    207th Meeting of the Electrochemical Society 2005  2005.5 

     More details

    Language:English   Presentation type:Oral presentation (invited, special)  

    researchmap

  • (国際会議)(招待講演)Recent Research and Development of Vacuum Ultraviolet Phosphorsfor Mercury-free Lamp International conference

    K. Toda

    International Conference on Rare Earths in Nara  2004.11 

     More details

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:奈良  

    researchmap

  • (国際会議)VUV Phosphors on Ternary System SrO-B2O3-P2O5 International conference

    Y. Komatsu, A. Komeno, K. Toda, K. Uematsu, M. Sato

    International Conference on Rare Earths in Nara  2004.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:奈良  

    researchmap

  • (国際会議)Luminescence Property of New VUV Phosphor Ba2MgSi2O7:Eu International conference

    A. Komeno, K. Toda, K. Uematsu, M. Sato

    International Conference on Rare Earths in Nara  2004.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:奈良  

    researchmap

  • (国際会議)Luminescence Properties of Red Long Persistent Phosphors, BaMg2Si2O7:Eu2+, Mn2+ International conference

    S. Abe, K. Uematsu, K. Toda, M. Sato

    International Conference on Rare Earths in Nara  2004.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:奈良  

    researchmap

  • (国際会議)Luminescence Properties of Long-persistent Slicate Phosphors International conference

    Y. Ito, A. Komeno, K. Uematsu, K. Toda, M. Sato

    International Conference on Rare Earths in Nara  2004.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:奈良  

    researchmap

  • (国際会議)Characterization of YVO4:Eu3+ Phosphors Synthesized by Microwave Heating Method International conference

    K. Uematsu, A. Ochiai, K. Toda, M. Sato

    International Conference on Rare Earths in Nara  2004.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:奈良  

    researchmap

  • (国際会議)Characterization of Potassium Niobate produced by Self-Assembled Nanosheet from Aqueous Solution International conference

    K. Toda, K. Shimizu, H. Sato, A. Sugawara, K. Uematsu, M. Sato

    The 8th IUMRS International Conference on Advanced Materials 2003  2003.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:横浜  

    researchmap

  • (国際会議)Characterization of Potassium Niobate produced by Self-Assembled Nanosheet from Aqueous Solution International conference

    K. Toda, N. Ohtake, M. Kawakami, S. Tokuoka, K. Uematsu, M. Sato

    International Joint Conference on the Applications of Ferroelectrics 2002  2002.5 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:奈良  

    researchmap

  • (国際会議)Hydrothermal Synthesis of Iron Phosphate Cathode Materials International conference

    S. Tajimi, H. Ohkawa, K. Uematsu, K. Toda, M. Sato

    International Conference on Solid State Ionics 2001  2001.6 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ケアンズ  

    researchmap

  • (国際会議)Room Temperature Synthesis and Characterization of Perovskite Compounds International conference

    K. Toda, S. Tokuoka, K. Uematsu, M. Sato

    International Conference on Solid State Ionics 2001  2001.6 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ケアンズ  

    researchmap

  • (国際会議)Synthesis and electrical properties of novel ion conducting rare earth perovskites International conference

    K. Toda, M. Sato, Y. Aoyama, N. Sakai

    Pacifichem2000  2000.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Search for New Superconducting Oxides using Soft Chemistry International conference

    K. Toda, T. Teranishi, Y. Tadahira, K. Uematsu, M. Sato

    International Symposium on Soft Solution Processing  2000.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:東京  

    researchmap

  • (国際会議)Room temperature synthesis and characterization of perovskite compounds International conference

    S. Tokuoka, K. Toda, K. Uematsu, M. Sato

    International Symposium on Soft Solution Processing  2000.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:東京  

    researchmap

  • (国際会議)Research and characterization of new long afterglow phosphors International conference

    K. Toda, Y. Imanari, J. Miyoshi, M. Sato

    Pacifichem2000  2000.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)New synthetic route of perovskite material in the test tube International conference

    K. Toda, S. Tokuoka, K. Uematsu, M. Sato

    The 1st Asian Meeting on Electroceramics  2000.10 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:横浜  

    researchmap

  • (国際会議)New synthetic route of perovskite material in the test tube International conference

    K. Toda, S. Tokuoka, K. Uematsu, M. Sato

    The Second International Conference on Inorganic Materials  2000.9 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:サンタバーバラ  

    researchmap

  • (国際会議)Synthesis and Electrical Properties Novel Ion Conducting Perovskites International conference

    M. Sato, K. Toda, Y. Aoyama, N. Sakai, M. Sasagawa

    The Second International Conference on Inorganic Materials  2000.9 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:サンタバーバラ  

    researchmap

  • (国際会議)Enhancement of discharge capacity of Li3V2(PO4)3 by stabilizing orthorhombic phase at room temperature International conference

    M. Sato, H. Ohkawa, K. Yoshida, M. Saito, K. Uematsu, K. Toda

    12th International Conference on Solid State Ionics  1999.8 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハルキディキ  

    researchmap

  • (国際会議)Oxygen defect of non-stoichiometric rare earth orthoniobate,LnxNbO4-1.5(1-x) International conference

    K. Toda, Y. Ishimoto, Z-G. Ye, M. Sato

    12th International Conference on Solid State Ionics  1999.8 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハルキディキ  

    researchmap

  • (国際会議)Application for Lithium Secondary Battery of Superionic Conductors, Li3-2x(In1-xZrx)2(PO4)3 (0≦x≦0.2 International conference

    K. Yoshikawa, N. Hayakawa, T. Suzuki, K. Uematsu, K. Toda, M. Sato

    ElectroceramicsⅥ  1998.8 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:モントレー  

    researchmap

  • (国際会議)Superconductivity of New Reduced Tantalates with a Layered Perovskite Structure International conference

    K. Toda, T. Teranishi, M. Sato

    ElectroceramicsⅥ  1998.8 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:モントレー  

    researchmap

  • (国際会議)Crystal Chemistry of New Luminescent Materials Containing Pentavalent Cation International conference

    S. Tobitsuka, T. Honma, T. Wakayama, K. Toda, M. Sato

    Electroceramics  1998.8 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:モントレー  

    researchmap

  • (国際会議)Stabilization of Superionic Conduction Phase in Li3Sc2(PO4)3 : Ionic Conductivity and Structure Refinement by Neutron Diffraction International conference

    M. Sato, T. Suzuki, K. Yoshida, K. Uematsu, T. Kodama, K. Toda, Z. -G. Ye

    11th International Conference on Solid State Ionics  1997.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Strutural Chemistry of New Ion-exchangeable Tantalates with Layered Perovskite Structure International conference

    K. Toda, S. Tobitsuka, Z-G. Ye, M. Sato

    11th International Conference on Solid State Ionics  1997.11 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

  • (国際会議)Synthesis and Property of New Layered Perovskite Compounds with Tantalum International conference

    K. Toda, Z-G. Ye, K. Yoshikawa, S. Tobitsuka, M. Sato

    The 4th IUMRS International Conference in Asia  1997.9 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:幕張  

    researchmap

  • (国際会議)Synthesis, Structure and Properties of the Magnetic Relaxor Ferroelectric Pb(Fe2/3W1/3)O3 [PFW] International conference

    Z-G. Ye, K. Toda, M. Sato, E. Kita, H. Schmid

    The 9th International Meeting on Ferroelectricity,  1997.8 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ソウル  

    researchmap

  • (国際会議)Synthesis and Property of New Layered Perovskite Compounds with Tantalum and Rare Earth International conference

    K. Toda, T. Honma, M. Sato

    TWENTY - FIRST RARE EARTH RESEARCH CONFERENCE  1996.7 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:アメリカ・ミネソタ  

    researchmap

  • (国際会議)Synthesis of Novel Intercalation Compounds, AgLnTiO4 and LiLnTiO4 (Ln = Rare earths) International conference

    K. Toda, S. Kurita, M. Sato

    環太平洋国際化学会議  1995.12 

     More details

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ハワイ  

    researchmap

▶ display all

Industrial property rights

  • 希土類フリー蛍光体の製造方法および希土類フリー蛍光体

    亀井 真之介, 古川 茂樹, 戸田 健司, 石垣 雅

     More details

    Application no:P2016-93405  Date applied:2016.5

    researchmap

  • 黒鉛被覆珪素複合体の製造方法

    戸田 健司, 佐藤 峰夫, 福岡 宏文, 福田 健

     More details

    Application no:P2015-218410  Date applied:2015.11

    researchmap

  • 窒化物蛍光体の製造方法

    初森 智紀, 松井 克己, 常世田 和彦, 鈴木 将治, 戸田 健司

     More details

    Application no:P2015-160259  Date applied:2015.8

    researchmap

  • 蛍光体、その製造方法及び発光装置

    戸田 健司, 大塩 祥三, 佐藤 夏希

     More details

    Application no:P2015-118830  Date applied:2015.6

    researchmap

  • 溶融塩型熱媒体

    戸田 健司, 佐藤 峰夫, 上松和義, 金 善旭, 椿 善太郎

     More details

    Application no:P2015-69896  Date applied:2015.3

    researchmap

  • 蛍光体及びこれを用いた発光装置

    戸田 健司, 阿部岳志, 佐藤 夏希, 大塩 祥三

     More details

    Application no:P2015-58055  Date applied:2015.3

    Announcement no:P2016-176017A  Date announced:2016.10

    researchmap

  • 蛍光体及びこれを用いた発光装置

    戸田 健司, 大塩 祥三, 佐藤 夏希

     More details

    Application no:P2014-105973  Date applied:2014.5

    researchmap

  • 緑色および黄色発光リン酸塩蛍光体

    戸田 健司, 佐藤 峰夫, 上松 和義, 金 善旭

     More details

    Application no:P2014-10336  Date applied:2014.1

    researchmap

  • Ce3+を賦活した酸化物蛍光体

    戸田 健司, 佐藤 峰夫, 上松 和義, 金 善旭

     More details

    Application no:P2014-10335  Date applied:2014.1

    researchmap

  • Ce3+賦活黄色および赤色発光蛍光体

    戸田 健司, 佐藤 峰夫, 上松 和義, 金 善旭

     More details

    Application no:P2014-10838  Date applied:2014.1

    researchmap

  • マンガン賦活赤色蛍光体

    戸田 健司, 佐藤 峰夫, 上松 和義, 金 善旭

     More details

    Application no:P2013-217914  Date applied:2013.10

    researchmap

  • リン酸塩系白色蛍光体

    戸田 健司, 佐藤 峰夫, 上松 和義, 金 善旭

     More details

    Application no:P2013-217915  Date applied:2013.10

    researchmap

  • 赤色珪素酸窒化物蛍光体及びその製造方法

    戸田 健司, 上松 和義, 佐藤 峰夫, 石垣 雅, 坂本 達矢, 塩原 利夫

     More details

    Application no:P2013-188499  Date applied:2013.9

    researchmap

  • フッ化物電極材料の合成方法

    戸田 健司, 佐藤 峰夫, 上松 和義, 石垣 雅

     More details

    Application no:P2013-176057  Date applied:2013.8

    researchmap

  • リン酸塩蛍光体、リン酸塩蛍光体の製造方法及びリン酸塩蛍光体を含んだ光源

    戸田 健司, 佐藤 峰夫, 上松 和義, 石垣 雅

     More details

    Application no:2013-43811  Date applied:2013.3

    Announcement no:2014-172919  Date announced:2014.9

    希土類元素を使用せずに、高い発光強度と高い熱安定性を発揮するリン酸塩蛍光体を提供する。
    リン酸塩蛍光体は、組成式Ba2(Ti1-xZrx)P2O9(式中、xはZrの濃度であり、0<x≦0.15である)を有することを特徴とする。さらに、xが0<x≦0.06であることが好ましい。また、TiO5の一部がZrO5で置換された結晶構造を有することが好ましい。この蛍光体の製造方法は、Baを含む原料(例えば、BaCO3)と、Pを含む原料(例えば、NH4H2PO4)と、Tiを含む原料(例えば、TiO2)と、Zrを含む原料(例えば、ZrO2)と、を秤量し、混合する混合工程と、混合物を粉砕する粉砕工程と、大気雰囲気下かつ1000℃~1150℃で前記混合物を焼成する焼成工程と、を含む。

    researchmap

  • テルビウムを賦活したケイ酸塩緑色蛍光体

    戸田 健司, 佐藤 峰夫, 上松 和義, 石垣 雅

     More details

    Application no:2013-42034  Date applied:2013.3

    Announcement no:2014-169390  Date announced:2014.9

    希土類元素を多量に使用せずに高い発光を示す蛍光体を提供する。
    本発明のテルビウムを賦活したケイ酸塩緑色蛍光体は、一般式:M1(M21-yTby)a(M31-xAlx)bOc(M1は少なくともBaを含む2価の金属元素、M2は少なくともYを含む3価の金属元素、M3は少なくともSiを含む4価の金属元素であり、0<x<0.20,0<y<0.20,a,b,cは0を含まない正の数)で表される組成からなる。

    researchmap

  • Ca-Sc(-Si)-O系蛍光体

    戸田 健司, 佐藤 峰夫, 上松 和義, 石垣 雅

     More details

    Application no:2012-246977  Date applied:2012.11

    Announcement no:2014-95029  Date announced:2014.5

    researchmap

  • 蛍光体及び発光装置

    戸田 健司, 石垣 雅, 亀井 真之介

     More details

    Application no:2012-50564  Date applied:2012.3

    Announcement no:2013-185045  Date announced:2013.9

    researchmap

  • リン酸塩蛍光体

    佐藤峰夫, 戸田健司, 上松和義, 石垣雅

     More details

    Application no:2012-43025  Date applied:2012.2

    Announcement no:2013-177523  Date announced:2013.9

    本発明は、組成式(M1-XZX)3R2(PO4)3(式中、MはLi、Na、K、Rb又はCsであり、ZはEu又はTbであり、RはY、Sc、Al又はGaであり、0<X<1である)を有する蛍光体を提供する。

    researchmap

  • 結晶性物質、並びにそれを用いた発光装置及び白色LED

    戸田 健司, 上松 和義, 佐藤 峰夫, 石垣 雅, 川上 義貴, 梅田 鉄

     More details

    Application no:2011-263896  Date applied:2011.12

    Announcement no:2012-131999  Date announced:2012.7

    researchmap

  • 結晶性物質の製造方法

    戸田 健司, 上松 和義, 佐藤 峰夫, 石垣 雅, 川上 義貴, 梅田 鉄

     More details

    Application no:2011-263594  Date applied:2011.12

    Announcement no:2012-132000  Date announced:2012.7

    researchmap

  • 蛍光体の製造方法

    戸田 健司, 上松 和義, 佐藤 峰夫, 佐藤 峰夫, 石垣 雅, 川上 義貴, 梅田 鉄

     More details

    Application no:2011-263598  Date applied:2011.12

    Announcement no:2012-132001  Date announced:2012.7

    researchmap

  • 蛍光体およびそれを用いた発光装置

    戸田 健司, 今成 裕一郎, 宮崎 進

     More details

    Application no:2011-245391  Date applied:2011.11

    Announcement no:2012-36407  Date announced:2012.2

    researchmap

  • 希土類元素の使用量の少ない蛍光ランプとそれに用いる蛍光体

    戸田 健司, 石垣 雅, 松久 昇

     More details

    Application no:2011-243866  Date applied:2011.11

    Announcement no:2013-100388  Date announced:2013.5

    光透過性管状外囲器、該光透過性管状外囲器の内壁に配置される蛍光膜、並びに該光透過性管状外囲器に封入される水銀及び希ガス、を有し、該水銀の放電によって放射される波長180nm~380nmの紫外線により該蛍光膜を発光させることで、光透過性管状外囲器から光を出射する蛍光ランプであって、
    前記蛍光膜は、蛍光体を構成する基本元素としてのLa源、Tb源、およびイオウ源、並びにアルカリ金属炭酸塩を原料として混合し、該混合物を焼成して得られるLaxOyS:Tb蛍光体(ただし、1.8≦x≦2.2、1.8≦y≦2.2)を含むことを特徴とする、蛍光ランプ。

    researchmap

  • 黄色蛍光体及びその製造方法

    戸田 健司, 上松 和義, 佐藤 峰夫, 石垣 雅, 川上 義貴, 梅田 鉄

     More details

    Application no:2011-240270  Date applied:2011.11

    Announcement no:2012-117049  Date announced:2012.6

    researchmap

  • 蛍光体及び発光装置

    戸田 健司, 石垣 雅

     More details

    Application no:2011-27496  Date applied:2011.2

    Announcement no:2012-167147  Date announced:2012.9

    researchmap

  • 蛍光体及び発光装置

    戸田 健司, 石垣 雅

     More details

    Application no:2011-27494  Date applied:2011.2

    Announcement no:2012-167146  Date announced:2012.9

    researchmap

  • 蛍光体の製造方法

    戸田 健司, 佐藤 峰夫, 上松 和義, 石垣 雅, 川添 博文, 美濃輪 武久, 福岡 宏文, 綿谷 和浩, 高井 康

     More details

    Application no:2011-6110  Date applied:2011.1

    Announcement no:2012-153737  Date announced:2012.8

    researchmap

  • 黄色蛍光体およびその製造方法

    戸田 健司, 上松 和義, 佐藤 峰夫, 石垣 雅, 川上 義貴, 梅田 鉄

     More details

    Application no:2010-269353  Date applied:2010.12

    Announcement no:2012-116980  Date announced:2012.6

    researchmap

  • ケイ素含有蛍光体及びその製造方法

    戸田 健司, 佐藤 峰夫, 上松 和義, 石垣 雅

     More details

    Application no:2010249682  Date applied:2010.11

    Announcement no:2012102183  Date announced:2012.5

    researchmap

  • SiOxを用いた蛍光体の被覆方法

    戸田 健司, 佐藤 峰夫, 上松 和義, 石垣 雅

     More details

    Application no:2010-249683  Date applied:2010.11

    Announcement no:2012-102184  Date announced:2012.5

    researchmap

  • バナジン酸塩の合成法

    戸田 健司

     More details

    Applicant:国立大学法人 新潟大学

    Application no:2009-160521  Date applied:2009.7

    Announcement no:2011-16670  Date announced:2011.1

    researchmap

  • 蛍光体、蛍光層形成用組成物、蛍光層及び発光装置

    戸田健司, 佐藤峰夫, 上松和義, 石垣雅, 川上 義貴, 梅田 鉄

     More details

    Applicant:国立大学法人 新潟大学 外1名

    Application no:2009-126893  Date applied:2009.5

    Announcement no:2010275370  Date announced:2010.12

    researchmap

  • 蛍光体及びそれを製造する方法、並びに蛍光層形成用組成物、蛍光層及び発光装置

    戸田健司, 佐藤峰夫, 上松和義, 石垣雅, 川上 義貴, 梅田 鉄

     More details

    Applicant:国立大学法人 新潟大学 外1名

    Application no:2009-126901  Date applied:2009.5

    Announcement no:2010-275372  Date announced:2010.12

    researchmap

  • 蛍光剤及びその製造方法、並びに蛍光層形成用組成物、蛍光層及び発光装置

    戸田健司, 佐藤峰夫, 上松和義, 石垣雅, 川上 義貴, 梅田 鉄

     More details

    Applicant:国立大学法人 新潟大学 外1名

    Application no:2009-126899  Date applied:2009.5

    Announcement no:2010275371  Date announced:2010.12

    researchmap

  • 蛍光体

    戸田 健司

     More details

    Application no:200925836  Date applied:2009.2

    Announcement no:2009-256596  Date announced:2009.11

    researchmap

  • 蛍光体及び蛍光体含有組成物、並びに、それを用いた発光装置、照明装置及び画像表示装置

    戸田 健司, 佐藤峰夫, 石垣雅, 上松和義, 関聡美, 下村康夫

     More details

    Applicant:国立大学法人 新潟大学 外1名

    Application no:2008-296931  Date applied:2008.11

    Announcement no:2010-121068  Date announced:2010.6

    researchmap

  • 近紫外線励起発光素子用蛍光体

    戸田 健司

     More details

    Applicant:国立大学法人 新潟大学 外1名

    Application no:2008-71108  Date applied:2008.3

    Announcement no:2009-227700  Date announced:2009.10

    researchmap

  • 蛍光体およびその製造方法

    戸田 健司

     More details

    Applicant:国立大学法人 新潟大学 外1名

    Application no:2008-71109  Date applied:2008.3

    Announcement no:2009-227701  Date announced:2009.10

    researchmap

  • アルコール濃度センサ

    上松 和義

     More details

    Applicant:国立大学法人 新潟大学 外1名

    Application no:2007-248733  Date applied:2007.9

    Announcement no:2009-79974  Date announced:2009.4

    researchmap

  • 真空紫外線励起発光素子用の蛍光体

    武田隆史

     More details

    Applicant:住友化学株式会社

    Application no:2007-138849  Date applied:2007.5

    Announcement no:2007-277567  Date announced:2007.5

    researchmap

  • 真空紫外線励起発光素子用の蛍光体

    武田隆史

     More details

    Applicant:住友化学株式会社

    Application no:2007-138850  Date applied:2007.5

    Announcement no:2007-246918  Date announced:2007.9

    researchmap

  • 蛍光体

    武田 隆史

     More details

    Applicant:住友化学株式会社

    Application no:2007-138848  Date applied:2007.5

    Announcement no:2007-284683  Date announced:2007.11

    researchmap

  • 真空紫外線励起発光素子用蛍光体

    渡辺 晃

     More details

    Applicant:株式会社ホソカワ粉体技術研究所 外1名

    Application no:2007-45342  Date applied:2007.2

    Announcement no:2008-208195  Date announced:2008.9

    researchmap

  • 空気中のラドン及びトロンの測定方法

    上松 和義, 佐藤 峰夫, 太田 雅壽, 戸田 健司

     More details

    Application no:PCT/JP2006/324798  Date applied:2006.12

    researchmap

  • 酸化チタンの製造法

    戸田 健司

     More details

    Applicant:国立大学法人 新潟大学

    Application no:2006-249441  Date applied:2006.9

    Announcement no:2008-69039  Date announced:2008.3

    researchmap

  • 発光ダイオード用蛍光体

    戸田 健司

     More details

    Applicant:国立大学法人 新潟大学

    Application no:2006-248748  Date applied:2006.9

    Announcement no:2008-69250  Date announced:2008.3

    researchmap

  • 窒化物及び酸窒化物の製造法

    戸田 健司

     More details

    Applicant:国立大学法人 新潟大学

    Application no:2006-248745  Date applied:2006.9

    Announcement no:2008-69035  Date announced:2008.3

    researchmap

  • ニオブ酸カリウムの低温製膜法

    戸田 健司

     More details

    Applicant:国立大学法人新潟大学

    Application no:2006-244764  Date applied:2006.9

    Announcement no:2008-063198  Date announced:2008.3

    researchmap

  • エレクトロルミネッセンス蛍光体

    戸田 健司

     More details

    Applicant:国立大学法人新潟大学

    Application no:2006-210226  Date applied:2006.8

    Announcement no:2008-037899  Date announced:2008.2

    researchmap

  • 紫外発光長残光蛍光体

    細梅 雅史, 戸田 健司, 上松 和義, 佐藤 峰夫

     More details

    Application no:PCT/JP2006/312832  Date applied:2006.6

    researchmap

  • 発光ダイオード用蛍光体

    戸田 健司, 佐藤 峰夫, 上松 和義, 高坂 真一郎, 川上 義貴

     More details

    Application no:PCT/JP2006/307139  Date applied:2006.4

    researchmap

  • 蛍光体用複合酸化物および蛍光体

    戸田 健司

     More details

    Applicant:国立大学法人新潟大学外1名

    Application no:2006-78273  Date applied:2006.3

    Announcement no:2007-254517  Date announced:2007.10

    researchmap

  • タンタル系酸窒化物光触媒及びその製造方法

    戸田健司

     More details

    Applicant:国立大学法人新潟大学

    Application no:2005-379575  Date applied:2005.12

    Announcement no:2007-175659  Date announced:2007.7

    researchmap

  • ニオブ酸カリウム単結晶及びその合成方法

    戸田健司

     More details

    Applicant:国立大学法人新潟大学

    Application no:2005-317464  Date applied:2005.10

    Announcement no:2007-119327  Date announced:2007.5

    researchmap

  • 長残光蛍光体

    上松和義

     More details

    Applicant:国立大学法人新潟大学

    Application no:2005-270684  Date applied:2005.9

    Announcement no:200777365  Date announced:2007.3

    researchmap

  • 蛍光体

    戸田健司

     More details

    Applicant:国立大学法人 新潟大学外1名

    Application no:2005-268013  Date applied:2005.9

    Announcement no:2007-77307  Date announced:2007.3

    researchmap

  • 白色LED

    戸田 健司

     More details

    Applicant:住友化学株式会社

    Application no:2005-46667  Date applied:2005.2

    Announcement no:2006-237113  Date announced:2006.9

    researchmap

  • 蛍光体およびそれを用いた発光装置

    戸田 健司

     More details

    Applicant:住友化学株式会社

    Application no:2005-46666  Date applied:2005.2

    Announcement no:2006-232906  Date announced:2006.9

    researchmap

  • 複合金属酸窒化物GaN-ZnO光触媒の製造方法

    戸田 健司

     More details

    Applicant:独立行政法人科学技術振興機構

    Application no:2004-306474  Date applied:2004.10

    Announcement no:2006-116415  Date announced:2006.5

    researchmap

  • 真空紫外線励起発光素子用の蛍光体

    戸田 健司

     More details

    Applicant:住友化学株式会社

    Application no:2004-135497  Date applied:2004.4

    Announcement no:2005-314596  Date announced:2005.11

    researchmap

  • 真空紫外線励起発光素子用蛍光体

    戸田 健司

     More details

    Applicant:住友化学株式会社

    Application no:2003-368465  Date applied:2003.10

    Announcement no:2005-132899  Date announced:2005.5

    researchmap

  • 発光材料およびそれを用いた発光材料利用装置

    櫻場 大樹

     More details

    Applicant:株式会社ティーエルオー

    Application no:2003-209550  Date applied:2003.8

    Announcement no:2005-75838  Date announced:2005.3

    researchmap

  • 真空紫外線励起発光素子用の蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:2003-184280  Date applied:2003.6

    Announcement no:2005-15678  Date announced:2005.1

    researchmap

  • 白色LED用蛍光体とそれを用いた白色LED

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:2003-53084  Date applied:2003.2

    Announcement no:2004-263020  Date announced:2004.9

    researchmap

  • 真空紫外線励起発光素子用の蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:2002-281219  Date applied:2002.9

    Announcement no:2004-115659  Date announced:2004.4

    researchmap

  • 真空紫外線励起発光素子用の蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:2002-272682  Date applied:2002.9

    Announcement no:2004-107504  Date announced:2004.4

    researchmap

  • 蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:2002-216354  Date applied:2002.7

    Announcement no:2004-59615  Date announced:2004.2

    researchmap

  • 真空紫外線励起発光素子用の蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:2002-189445  Date applied:2002.6

    Announcement no:2004-27143  Date announced:2004.1

    researchmap

  • 酸化チタンの製造法

    戸田 健司

     More details

    Applicant:鍋林電子工業株式会社

    Application no:2002-192741  Date applied:2002.5

    Announcement no:2004-2128  Date announced:2004.1

    researchmap

  • 白色LED用蛍光体とそれを用いた白色LED

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:2002-112068  Date applied:2002.4

    Announcement no:2003-306674  Date announced:2003.10

    researchmap

  • 真空紫外線励起発光素子用の蛍光体

    武田 隆史

     More details

    Applicant:住友化学工業株式会社

    Application no:2001-259235  Date applied:2001.8

    Announcement no:2002-332481  Date announced:2002.11

    researchmap

  • 真空紫外線励起発光素子用蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:平11-366995  Date applied:1999.12

    Announcement no:2001-181625  Date announced:2001.7

    researchmap

  • 真空紫外線励起発光素子用蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:平11-366993  Date applied:1999.12

    Announcement no:2001-181630  Date announced:2001.7

    researchmap

  • 真空紫外線励起発光素子用蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:平11-366992  Date applied:1999.12

    Announcement no:2001-181629  Date announced:2001.7

    researchmap

  • 真空紫外線励起発光素子用蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:平11-366994  Date applied:1999.12

    Announcement no:2001-181628  Date announced:2001.7

    researchmap

  • 真空紫外線励起発光素子用蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:平11-366996  Date applied:1999.12

    Announcement no:2001-181627  Date announced:2001.7

    researchmap

  • 真空紫外線励起発光素子用蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:平11-366998  Date applied:1999.12

    Announcement no:2001-181623  Date announced:2001.7

    researchmap

  • 真空紫外線励起発光素子用蛍光体

    戸田 健司

     More details

    Applicant:住友化学工業株式会社

    Application no:平11-366997  Date applied:1999.12

    Announcement no:2001-181626  Date announced:2001.7

    researchmap

  • 燐酸リチウム・バナジウム複合化合物及び同複合化合物からなるリチウムイオン二次電池用正極材料

    佐藤 峰夫

     More details

    Applicant:大阪大学長

    Application no:平10-261930  Date applied:1998.9

    Announcement no:2000-86215  Date announced:2000.3

    researchmap

  • リチウムイオン伝導性固体電解質及び電気化学的素子

    今中 信人

     More details

    Applicant:大阪大学長

    Application no:平9-313649  Date applied:1997.11

    Announcement no:平11-149820  Date announced:1999.6

    researchmap

▶ display all

Awards

  • IDW '14 Best Paper Award

    2014.12   一般社団法人ディスプレイ国際ワークショップ   Synthesis of LaPO4: Ce3+, Tb3+ Phosphors by Solid Hydrate Thermal Processing

    Synthesis of LaP, Ce3+, Tb, Phosphors by Solid, Hydrate Thermal Processing

     More details

    Award type:Award from international society, conference, symposium, etc.  Country:Japan

    researchmap

  • IDW '13 Outstanding Poster Paper Award

    2013.12   一般社団法人ディスプレイ国際ワークショップ  

    H. Mizobuchi, K. Uematsu, S. W. Kim, T. Ishigaki, K. Toda, M. Sato

     More details

    Award type:Award from international society, conference, symposium, etc.  Country:Japan

    researchmap

  • 平成25年日本希土類学会賞(塩川賞)

    2012.11   日本希土類学会  

    戸田健司

     More details

    Award type:International academic award (Japan or overseas)  Country:Japan

    researchmap

  • IDW '10 Outstanding Poster Paper Award

    2010.12   第18回ディスプレイ国際ワークショップ  

    Tadashi Ishigaki, Kenji Toda, Tatsuya Sakamoto, Kazuyoshi Uematsu, Mineo Sato

     More details

    Award type:Award from international society, conference, symposium, etc.  Country:Japan

    researchmap

  • IDW/AD '05 Outstanding Poster Paper Award

    2005.12   第12回ディスプレイ国際ワークショップ/アジアディスプレイ2005  

    Kenji Toda, Yoshitaka Kawakami, Shinichiro Kousaka, Yutaka Ito, Akira Komeno, Kazuyoshi Uematsu, Mineo Sato

     More details

    Award type:Award from international society, conference, symposium, etc.  Country:Japan

    researchmap

Research Projects

  • 気相単結晶育成による白色LED用新規窒化物蛍光体材料の探索

    2017.4 - 2019.3

    System name:科学研究費助成事業

    Research category:基盤研究(B)

    Awarding organization:日本学術振興会

    戸田 健司

      More details

    Authorship:Principal investigator  Grant type:Competitive

    researchmap

  • マルチ発光中心を有する単一母結晶蛍光体の材料設計とLED用蛍光体への展開

    2017.4 - 2019.3

    System name:科学研究費助成事業

    Research category:基盤研究(B)

    Awarding organization:日本学術振興会

    佐藤 峰夫

      More details

    Grant type:Competitive

    researchmap

  • 金属化合物の合成手法と光学特性の研究

    2010.4 - 2012.3

    System name:共同研究(国内共同研究)

    Awarding organization:住友化学株式会社

      More details

    Grant type:Competitive

    Grant amount:\4620000

    researchmap

  • 非平衡法による複合酸化物光学材料の合成

    2010.4 - 2011.3

    System name:共同研究(国内共同研究)

    Awarding organization:東京工業大学

      More details

    Grant type:Competitive

    researchmap

  • LED照明用新規高性能蛍光体の開発

    2010.4 - 2011.3

    System name:共同研究(国内共同研究)

    Awarding organization:パナソニック電工株式会社

      More details

    Grant type:Competitive

    Grant amount:\6600000

    researchmap

  • NEDO希少金属代替プロジェクト「蛍光体向けテルビウム・ユーロピウム使用量低減技術開発及び代替材料開発」

    2009.7

    System name:受託研究(一般受託研究)

      More details

    Grant type:Competitive

    researchmap

  • 省エネルギー革新技術開発事業/実用化開発/高輝度・高効率な電解電子放出型光源の研究開発/長寿命、高効率蛍光体の開発

    2009.7 - 2011.3

    System name:受託研究(一般受託研究)

    Awarding organization:高知FEL株式会社

      More details

    Grant type:Competitive

    Grant amount:\23000000

    researchmap

  • LED照明用新規高性能蛍光体の開発

    2009.4

    System name:共同研究(学内共同研究)

      More details

    Grant type:Competitive

    researchmap

  • NEDO省エネルギー革新技術開発事業「高輝度・高効率な電界電子放出型光源の研究開発」(再委託)

    2009.4

    System name:受託研究(一般受託研究)

      More details

    Grant type:Competitive

    researchmap

  • セラミックス材料粉末の形態制御

    2009.3 - 2012.3

    System name:共同研究(国際共同研究)

      More details

    Grant type:Competitive

    Grant amount:\3000000

    researchmap

  • 発光体の開発

    2008.12

    System name:共同研究(国内共同研究)

    Awarding organization:リードケミカル株式会社/株式会社新潟TLO

      More details

    Grant type:Competitive

    Grant amount:\2000000

    researchmap

  • 流動層によるセラミクス材料の合成

    2007.7

    System name:共同研究(国内共同研究)

    Awarding organization:松下電器産業株式会社

      More details

    Grant type:Competitive

    Grant amount:\1000000

    researchmap

  • 革新的環境・エネルギー触媒の開発(新規光触媒材料の開発および構造解析)

    2007.4 - 2011.3

    System name:受託研究(一般受託研究)

    Awarding organization:文部科学省

      More details

    Grant type:Competitive

    Grant amount:\3250000

    researchmap

  • 圧電体単結晶の作成と評価

    2006.4

    System name:共同研究(国内共同研究)

    Awarding organization:東京大学先端研

      More details

    Grant type:Competitive

    researchmap

  • 新規な蛍光体材料の開発

    2006.4

    System name:共同研究

    Awarding organization:久留米高専

      More details

    Grant type:Competitive

    researchmap

  • 酸化チタンの特性評価・解析に関する研究

    2006.4 - 2007.3

    System name:共同研究

    Awarding organization:株式会社コーセー 研究本部

      More details

    Grant type:Competitive

    Grant amount:\1500000

    researchmap

  • ソフトケミストリーを利用した新規な光触媒の合成および評価

    2006.4 - 2007.3

    System name:戦略的創造研究推進事業

    Awarding organization:独立行政法人科学技術振興機構 戦略的創造事業本部

      More details

    Grant type:Competitive

    Grant amount:\390000 ( Direct Cost: \390000 )

    researchmap

  • 窒素含有光学セラミックスの開発と評価

    2006.4 - 2007.3

    System name:共同研究

    Awarding organization:株式会社三菱化学科学技術研究センター

      More details

    Grant type:Competitive

    Grant amount:\1000000

    researchmap

  • マイクロ波加熱法による機能性無機材料の合成反応の探索

    2006.1 - 2008.12

    System name:科学研究費助成事業

    Research category:基盤研究(B)

    Awarding organization:日本学術振興会

      More details

    Grant type:Competitive

    現在、リチウムイオン二次電池の正極材料にはLiCoO_2やLiNiO_2などが主に用いられているが、今後の電池の大型化、量産化に耐えうる材料の開発が求められている。鉄系化合物は環境負荷が小さく、資源的に豊富なことから、その有力候補に挙げられている。中でもolivine構造を持つLiFePO_4は理論容量が170mAh/gと比較的高いことから注目されている。マイクロ波加熱では対象物に直接エネルギーが付与されるため、急速加熱と高い熱効率が得られるという大きな特徴がある。本研究では、省エネルギー、時間短縮、低コスト化が期待できるこの技術をLiFePO_4の合成に適用した。合成には家庭用電子レンジ(2。45GHz、高周波出力500W)を用い、試料の温度測定と温度制御を行った。仮焼成時および合成時は鉄の酸化を防ぐため、試料を石英製反応管に入れ、アルゴンガスを流した。得られた試料はXRD測定、充放電特性測定、SEM観察等を行った。LiFePO_4原料の誘電特性を測定したところ、鉄源であるFeOとC_4H

    researchmap

  • 蛍光体微粒子の特性評価・解析に関する研究

    2006.1 - 2006.12

    System name:共同研究

    Awarding organization:株式会社ホソカワ粉体技術研究所

      More details

    Grant type:Competitive

    Grant amount:\2000000

    researchmap

  • 鉱石からの金属元素の抽出

    2005.4 - 2006.3

    System name:共同研究

    Awarding organization:株式会社サンテック

      More details

    Grant type:Competitive

    Grant amount:\1000000

    researchmap

  • 蛍光体微粒子の特性評価・解析

    2005.2 - 2005.12

    System name:共同研究

    Awarding organization:株式会社ホソカワ粉体技術研究所

      More details

    Grant type:Competitive

    researchmap

  • チェレンコフ光を利用した大気中ラドンの新規測定方法の開発

    2005.1 - 2006.12

    System name:科学研究費助成事業

    Research category:萌芽研究

      More details

    Grant type:Competitive

    本研究はラドンおよびトロンの壊変過程に高エネルギーベータ線を放出する核種が存在することに着目したものである.昨年度までの研究の結果,(1)検出素子には多孔質ガラス吸着剤を冷却して用いることにより空気中のラドン・トロンを吸着濃縮できる,(2)吸着剤には透光性のある石英質の多孔質ガラスや多孔質の高分子材料(ポリスチレンなど)が使用できる,(3)液体シンチレーターを使用しないためトルエンなどの有害有機廃液がでない,(4)測定には汎用的な液体シンチレーション計測装置が使用可能である,(5)娘核種ではなくラドン・トロンを直接捕集するので実際のラドン・トロン濃度の測定が可能である,(6)減衰時間の違いからラドンとトロンの区別及びその混合割合が測定可能である,(7)検出素子は吸着したラドン・トロンの娘核種の減衰を待つことにより繰り返し使用が可能である,などの特徴を有することが明らかとなった.
    本年度は,大気を採取する際に適当な容積のバッファタンク(減

    researchmap

  • 可視光照射下での水の完全分解反応を目指した光触媒材料の探索と構築

    2004.11 - 2006.3

    System name:受託研究

    Awarding organization:独立行政法人 科学技術振興機構

      More details

    Grant type:Competitive

    Grant amount:\390000

    researchmap

  • 可視光照射下での水の完全分解反応を目指した光触媒材料の探索と構築(戦略的創造研究推進事業)

    2004.11 - 2006.3

    System name:受託研究

    Awarding organization:独立行政法人 科学技術振興機構

      More details

    Grant type:Competitive

    Grant amount:\247000

    researchmap

  • 排水処理用セラミックス材料の開発

    2003.6 - 2004.3

    System name:共同研究

    Awarding organization:同和クリーンテックス株式会社

      More details

    Grant type:Competitive

    Grant amount:\500000

    researchmap

  • プラズマディスプレイ用蛍光体の開発

    2001.9 - 2007.3

    System name:共同研究

    Awarding organization:住友化学工業株式会社筑波研究所

      More details

    Grant type:Competitive

    Grant amount:\6250000

    researchmap

  • プラズマディスプレイ用蛍光体の開発

    2001.9 - 2007.3

    System name:共同研究

    Awarding organization:住友化学工業株式会社筑波研究所

      More details

    Grant type:Competitive

    Grant amount:\2100000

    researchmap

  • 廃棄アスベストからの超高輝度長残光蛍光体の作製

    2001.1 - 2002.12

    System name:科学研究費助成事業

    Research category:若手研究(B)

    Awarding organization:日本学術振興会

      More details

    Grant type:Competitive

    最近社会問題となっている廃棄物として、発ガン性のあるアスベストが挙げられる。現在使用されているアスベストは、比較的発ガン性の低いクリソタイル鉱石のみであるが、将来的には使用が制限されると考えられる。アスベストの発ガン性は、その繊維状の形態によるものであり、成分の毒性ではない。そこで、形態を変えて有用性の高い材料に転換すれば再利用は可能である。
    クリソタイルは、長残光蛍光体Sr-Akermaniteの成分と共通するマグネシウムと珪素を主成分とした鉱石である。本研究では、クリソタイルと同じ組成を持つ天然鉱石"蛇紋岩"および廃アスベストを原料に、珪酸塩系の長残光蛍光体Sr-Akermaniteの合成を検討した。鉱石中に存在する鉄やニッケル等の遷移金属類を除去するためには酸処理を行うことが有用であり、大半の不純物は除去できる。酸処理原料を用いて合成したSr-Akermaniteの発光および残光を確認することができ、その発光特性は、高純度原料より合成した

    researchmap

  • 高濃度付活蛍光体の高輝度化

    1997.1 - 1999.12

    System name:科学研究費助成事業

    Research category:基盤研究(S)

    Awarding organization:日本学術振興会

      More details

    Grant type:Competitive

    本研究では、発光イオンが一次元鎖や二次元面に配置された特異な結晶構造を持つ化合物において高い輝度を持つ化合物を探索するとともに、発光イオン間の励起エネルギー移動に関する基本的な知見を得ることを目的としている。まず、モデル化合物として、希土類イオンが二次元面を形成している層状ペロブスカイト化合物における発光の濃度依存性を研究した。これらの化合物における濃度消光をEu^<3+>サイト間のパーコレーションモデルで説明し、励起エネルギー移動の機構を最隣接サイト間の多極子-多極子相互作用であることを結論づけた。これらの結論より、アパタイト構造を持つGe化合物を合成した。この化合物における発光イオン間の距離はエネルギー移動の臨界距離に近く、それにより濃度消光を抑制し、市販の高輝度蛍光体を上回る輝度が得られた。
    また、我々が合成に成功した層状ペロブスカイトおよびGe酸化物の単結晶を育成し、その物性の評価を行った。単結晶

    researchmap

▶ display all

 

Teaching Experience (researchmap)

▶ display all

Teaching Experience

  • 大型機器分析技術

    2022
    Institution name:新潟大学

  • 無機材料物性化学

    2021
    Institution name:新潟大学

  • リメディアル演習

    2021
    Institution name:新潟大学

  • 技術文献リサーチA

    2020
    Institution name:新潟大学

  • 技術文献リサーチB

    2020
    Institution name:新潟大学

  • 技術文献リサーチD

    2020
    Institution name:新潟大学

  • 技術文献リサーチC

    2020
    Institution name:新潟大学

  • 卒業研究

    2018
    Institution name:新潟大学

  • 無機化学実験(工)

    2018
    Institution name:新潟大学

  • 卒業研修

    2017
    Institution name:新潟大学

  • 工学リテラシー入門(化学材料分野)

    2017
    Institution name:新潟大学

  • 基礎無機化学

    2017
    Institution name:新潟大学

  • 論文輪講I

    2017
    -
    2019
    Institution name:新潟大学

  • 論文輪講II

    2017
    -
    2018
    Institution name:新潟大学

  • 中間発表

    2015
    Institution name:新潟大学

  • 材料生産システム博士特定研究Ⅱ

    2015
    Institution name:新潟大学

  • 外国語論文解説・討論Ⅱ

    2015
    Institution name:新潟大学

  • 材料生産システム博士セミナーⅡ

    2015
    Institution name:新潟大学

  • 外国語論文解説・討論Ⅰ

    2014
    Institution name:新潟大学

  • 材料生産システム博士セミナーⅠ

    2014
    Institution name:新潟大学

  • 材料生産システム博士特定研究Ⅰ

    2014
    Institution name:新潟大学

  • 素材生産科学コース演習

    2014
    Institution name:新潟大学

  • 自然科学総論Ⅱ

    2013
    -
    2018
    Institution name:新潟大学

  • 素材生産科学セミナーⅠ

    2013
    -
    2015
    Institution name:新潟大学

  • 材料生産システム特定研究Ⅰ

    2013
    -
    2015
    Institution name:新潟大学

  • 素材生産科学セミナーⅡ

    2013
    -
    2015
    Institution name:新潟大学

  • 研究発表演習・発表

    2013
    -
    2015
    Institution name:新潟大学

  • 材料生産システム特定研究Ⅱ

    2013
    -
    2015
    Institution name:新潟大学

  • 素材生産科学文献詳読Ⅰ

    2012
    -
    2015
    Institution name:新潟大学

  • 素材生産科学特別演習

    2012
    -
    2015
    Institution name:新潟大学

  • 素材生産科学文献詳読Ⅱ

    2012
    -
    2015
    Institution name:新潟大学

  • 情報機器操作入門

    2012
    Institution name:新潟大学

  • 工学リテラシー入門(化学システム工学科)

    2009
    -
    2011
    Institution name:新潟大学

  • 化学技術英語

    2008
    Institution name:新潟大学

  • 化学システム工学入門

    2008
    Institution name:新潟大学

  • 最先端技術を支える化学 I

    2007
    Institution name:新潟大学

  • 無機合成化学

    2007
    Institution name:新潟大学

  • 無機工業化学

    2007
    Institution name:新潟大学

  • 応用化学演習I

    2007
    Institution name:新潟大学

  • 無機材料設計

    2007
    -
    2020
    Institution name:新潟大学

  • 無機材料物性化学

    2007
    -
    2018
    Institution name:新潟大学

  • 無機化学実験

    2007
    -
    2017
    Institution name:新潟大学

  • 応用化学実習

    2007
    Institution name:新潟大学

▶ display all