2022/12/01 更新

写真a

ヒロセ ユウスケ
廣瀬 雄介
HIROSE Yusuke
所属
教育研究院 自然科学系 数理物質科学系列 助教
自然科学研究科 数理物質科学専攻 助教
理学部 理学科 助教
職名
助教
外部リンク

学位

  • 博士(理学) ( 2012年9月   大阪大学 )

研究キーワード

  • 励起子絶縁体

  • 超伝導

  • 強相関電子系

  • 単結晶育成

  • 圧力下物性測定

研究分野

  • 自然科学一般 / 磁性、超伝導、強相関系

経歴(researchmap)

  • 大阪大学   理学研究科   大学院生

    2008年4月 - 2012年9月

      詳細を見る

  • 神戸大学   理学部

    2004年4月 - 2008年3月

      詳細を見る

経歴

  • 新潟大学   理学部 理学科   助教

    2017年4月 - 現在

  • 新潟大学   自然科学研究科 数理物質科学専攻   助教

    2012年10月 - 現在

  • 新潟大学   自然科学研究科 数理物質科学専攻   助教

    2012年10月 - 現在

  • 新潟大学   物性科学   助教

    2012年10月 - 2017年3月

 

論文

  • Antiferromagnetic order in Yb4Ru7As6 with the cubic U4Re7Si6-type structure

    Yusuke Hirose, Kyoma Arakawa, Yuta Kato, Yoshiya Uwatoko, Hanming Ma, Jun Gouchi, Fuminori Honda, Rikio Settai

    Journal of Magnetism and Magnetic Materials   556   169327 - 169327   2022年8月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier {BV}  

    DOI: 10.1016/j.jmmm.2022.169327

    researchmap

  • Elastic Soft Mode and Electric Quadrupole Response in Excitonic Insulator Candidate (Ta0.952V0.048)2NiSe5: Contribution of Electron–Phonon Interaction

    Ryosuke Kurihara, Yusuke Hirose, Sumika Sano, Keisuke Mitsumoto, Atsushi Miyake, Masashi Tokunaga, Rikio Settai

    Journal of the Physical Society of Japan   91 ( 2 )   2022年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    We performed ultrasonic measurements on (Ta0.952V0.048)(2)NiSe5 to investigate the contribution of acoustic phonons at the zone center to structural and possible excitonic transitions. The transverse elastic constant C-55 with irreducible representation B-2g exhibits softening over 90% above a transition temperature of T-s = 280 K, indicating the soft mode of corresponding TA phonons. Our analysis based on the quadrupole response indicates that the electron-phonon interaction contributes to the excitonic transition in addition to the hybridization between the conduction and valence bands if the excitonic transition is realized.

    DOI: 10.7566/JPSJ.91.024601

    Web of Science

    researchmap

  • Two-gap time reversal symmetry breaking superconductivity in noncentrosymmetric LaNiC2

    Sundar, S., Dunsiger, S.R., Gheidi, S., Akella, K.S., Côté, A.M., Özdemir, H.U., Lee-Hone, N.R., Broun, D.M., Mun, E., Honda, F., Sato, Y.J., Koizumi, T., Settai, R., Hirose, Y., Bonalde, I., Sonier, J.E.

    Physical Review B   103 ( 1 )   2021年

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:American Physical Society (APS)  

    DOI: 10.1103/PhysRevB.103.014511

    Scopus

    researchmap

  • Symmetry Lowering on the Field-Induced Commensurate Phase in CeRhIn5 査読

    Tomoki Kanda, Koki Arashima, Yusuke Hirose, Rikio Settai, Kazuki Matsui, Toshihiro Nomura, Yoshimitsu Kohama, Yoshihiko Ihara

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   89 ( 9 )   2020年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    Temperature dependence of the In-115-NMR spectra of CeRhIn5 is studied with the external magnetic fields 10 degrees off the [100] and [001] axes. Our detailed analyses confirm that the AFM3 phase breaks the four-fold spin symmetry with the commensurate ordering vector of Q = (0. 5, 0.5, 0.25). Based on the observation of anistropic hyperfine fields, we also propose the symmetry lowering of the electronic structure in the AFM3 phase.

    DOI: 10.7566/JPSJ.89.094709

    Web of Science

    researchmap

  • High-field ultrasonic study of quadrupole ordering and crystal symmetry breaking in CeRhIn_5 査読

    101 ( 15 )   155125-1 - 155125-8   2020年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1103/PhysRevB.101.155125

    Scopus

    researchmap

  • Magnetic and electronic properties of the ternary compound U2T3Si5 (T=Rh, Ir) 査読

    Fuminori HONDA, Naomi KAWAMURA, Dexin LI, Yusuke HIROSE, Yoshiya HOMMA, Ai NAKAMURA, Yusei SHIMIZU, Arvind MAURYA, Yoshiki J. SATO, and Dai AOKI

    JPS Conf. Proc.   29   013002-1 - 013002-6   2020年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    researchmap

  • Magnetic structure of Cd-doped CeIrIn5

    Beauvois, K., Qureshi, N., Tsunoda, R., Hirose, Y., Settai, R., Aoki, D., Rodiere, P., McCollam, A., Sheikin, I

    Physical Review B   2020年

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    DOI: 10.1103/PHYSREVB.101.195146

    Web of Science

    researchmap

  • Temperature–pressure phase diagram of antiferromagnet CeAl 査読

    Ryoma Tsunoda, Yusuke Hirose, Takuto Koitabashi, Yoshiyuki Sase, Ruta Kulkarni, Arumugam Thamizhavel, Sudesh Kumar Dhar, Jun Gouchi, Yoshiya Uwatoko, Rikio Settai

    Journal of the Physical Society of Japan   88 ( 3 )   2019年

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    ©2019 The Physical Society of Japan We studied the pressure effect up to 8 GPa on antiferromagnet CeAl by means of ac specific heat Cac, ac susceptibility χA, and electrical resistivity ρ, and constructed temperature–pressure phase diagram. CeAl undergoes an antiferromagnetic (AFM) ordering at TN1 ∼ 10 K at ambient pressure, which is changed to three successive AFM transition temperatures ðTN2; TN3; TN4Þ above 1.7 GPa. AFM transition temperatures attain a maximum at 6.0 GPa and seem to vanish at P+ = 7.5 GPa. A pressure induced phase, which emerges above 4.5 GPa, is also developed around P+. We analyzed low temperature resistivity in order to study quantum criticality around P+

    DOI: 10.7566/JPSJ.88.034707

    Web of Science

    Scopus

    researchmap

  • Electronic states of CeT<inf>2</inf>X<inf>20</inf> (T:transition metal, X=Zn and Cd) 査読

    Yusuke Hirose, Yoshitaka Suzuki, Fuminori Honda, Ruta Kulkarni, Arumugam Thamizhavel, Naomi Kawamura, Masaichiro Mizumaki, Ryohei Simokasa, Kojiro Mimura, Hiroshi Doto, Rikio Settai

    AIP Advances   8 ( 11 )   2018年11月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2018 Author(s). The electronic state of single crystals of CeIr2(Zn1-xCdx)20 and CePt2Cd20 has been studied by measuring the electrical resistivity ρ and specific heat C. We found that by substituting Zn with Cd, the lattice parameter expands, and the electronic specific heat coefficient γ and A coefficient, which is T2-term in ρ, are enhanced. Our experimental results reveal that the electronic state of the intermediate valence compound CeIr2Zn20 changes to a moderately heavy fermion state due to the negative chemical pressure. On the other hand, C and ρ of CePt2Cd20 show a clear jump and an abrupt change of slope below 0.3 K, respectively, due to a magnetic transition. The relation between the hybridization strength and Ce valence state has also been investigated by X-ray absorption experiment.

    DOI: 10.1063/1.5043138

    Web of Science

    Scopus

    researchmap

  • Quasi-two-dimensional Fermi surfaces with localized f electrons in the layered heavy-fermion compound CePt2In7 査読

    K. Götze, Y. Krupko, J. A.N. Bruin, J. Klotz, R. D.H. Hinlopen, S. Ota, Y. Hirose, H. Harima, R. Settai, A. McCollam, I. Sheikin

    Physical Review B   96 ( 7 )   2017年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER PHYSICAL SOC  

    © 2017 American Physical Society. We report measurements of the de Haas-van Alphen effect in the layered heavy-fermion compound CePt2In7 in high magnetic fields up to 35 T. Above an angle-dependent threshold field, we observed several de Haas-van Alphen frequencies originating from almost ideally two-dimensional Fermi surfaces. The frequencies are similar to those previously observed to develop only above a much higher field of 45 T, where a clear anomaly was detected and proposed to originate from a change in the electronic structure [M. M. Altarawneh et al., Phys. Rev. B 83, 081103 (2011)PRBMDO1098-012110.1103/PhysRevB.83.081103]. Our experimental results are compared with band structure calculations performed for both CePt2In7 and LaPt2In7, and the comparison suggests localized f electrons in CePt2In7. This conclusion is further supported by comparing experimentally observed Fermi surfaces in CePt2In7 and PrPt2In7, which are found to be almost identical. The measured effective masses in CePt2In7 are only moderately enhanced above the bare electron mass m0, from 2m0 to 6m0.

    DOI: 10.1103/PhysRevB.96.075138

    Web of Science

    Scopus

    researchmap

  • Characteristic physical properties of the non-Kramers Γ<inf>3</inf> ground state in PrPt<inf>2</inf>Cd<inf>20</inf> 査読

    Yusuke Hirose, Tetsuya Takeuchi, Hiroshi Doto, Fuminori Honda, Atsushi Miyake, Masashi Tokunaga, Daichi Yoshizawa, Takanori Kida, Masayuki Hagiwara, Yoshinori Haga, Rikio Settai

    Journal of the Physical Society of Japan   86 ( 7 )   2017年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    ©2017 The Physical Society of Japan. The 4 f crystalline electric field (CEF) of the Pr 3+ ion of PrPt2Cd20 with a cubic crystal structure has been studied by measuring its high-field magnetization up to 45 T, specific heat in a wide temperature range in magnetic fields, and electrical resistivity. Magnetization curves for the magnetic field along the [100] and [110] directions show metamagnetic-like features at approximately 1.5 and 15 T, respectively. The specific heat shows a Schottky peak centered at 2.4 K. These experimental results were explained well by the CEF scheme with the non-Kramers Γ3 doublet ground state with a small overall CEF splitting energy of about 40 K. The specific heat also shows another broad peak below 1 K with an associated entropy release of R ln 2. This peak was interpreted by a split of the Γ3 doublet ground state with an energy of Δ = 0.4 K. These results suggest that the local symmetry of the Pr site is lowered from a cubic one. The possible reasons for this symmetry lowering are discussed.

    DOI: 10.7566/JPSJ.86.074711

    Web of Science

    Scopus

    researchmap

  • Determination of the magnetic structure of CePt2In7 by means of neutron diffraction 査読

    M. Raba, E. Ressouche, N. Qureshi, C. V. Colin, V. Nassif, S. Ota, Y. Hirose, R. Settai, P. Rodière, I. Sheikin

    Physical Review B   95 ( 16 )   2017年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER PHYSICAL SOC  

    © 2017 American Physical Society. The magnetic structure of the heavy fermion antiferromagnet CePt2In7 is determined using neutron diffraction. We find a magnetic wave vector qM=(1/2,1/2,1/2), which is temperature independent up to TN=5.5 K. A staggered moment of 0.45(1)μB at 2 K resides on the Ce ion. The nearest-neighbor moments in the tetragonal basal plane are aligned antiferromagnetically. The moments rotate by 90 from one CeIn3 plane to another along the c axis. A much weaker satellite peak with an incommensurate magnetic wave vector qM=(1/2,1/2,0.47) seems to develop at low temperature. However, the experimental data available so far are not sufficient to draw a definitive conclusion about the possible coexistence of commensurate and incommensurate magnetic structures in this material.

    DOI: 10.1103/PhysRevB.95.161102

    Web of Science

    Scopus

    researchmap

  • Single crystal growth and electronic state of new compounds RPt<inf>2</inf>Cd<inf>20</inf>(R = La-Nd, Sm) 査読

    Hiroshi Doto, Yusuke Hirose, Fuminori Honda, Tetsuya Takeuchi, Yoshinori Haga, Rikio Settai

    Journal of Alloys and Compounds   693   332 - 338   2017年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    © 2016 Elsevier B.V. We succeeded in growing five new single crystalline compounds RPt2Cd20(R = La, Ce, Pr, Nd, and Sm) by the Cd self-flux method. These compounds are found to crystallize in the cubic CeCr2Al20-type crystal structure by the X-ray diffraction using single crystals. We measured the electrical resistivity, magnetic properties, and specific heat for all compounds. The resistivity for R = Ce, Nd, and Sm indicates an abrupt decrease, which might correspond to a magnetic transition. It is suggested that the ground state of CePt2Cd20is Γ7doublet from the magnetization measurement. The magnetization of PrPt2Cd20shows a metamagnetic behavior at 1.6 T in the paramagnetic state, which could be due to the crystalline electric field effect with non-Kramers Γ3doublet or Γ1singlet ground state. The contribution of optical phonon modes to the lattice specific heat is discussed in LaPt2Cd20.

    DOI: 10.1016/j.jallcom.2016.09.077

    Web of Science

    Scopus

    researchmap

  • High-quality single crystal growth and strongly correlated electronic states in rare earth and actinide compounds 査読

    Yoshichika Onuki, Fuminori Honda, Yusuke Hirose, Rikio Settai, Tetsuya Takeuchi

    Reports on Progress in Physics   79 ( 11 )   2016年10月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2016 IOP Publishing Ltd. We review the nature of strongly correlated electronic states in rare earth and actinide compounds, focusing on localized versus itinerant electronic states in CeRhIn5, quantum critical phenomena in YbIr2Zn20, residual resistivity in CeCu6, metamagnetism in heavy fermion compounds, and unconventional superconductivity in CeIrSi3 without inversion symmetry in the crystal structure, emphasizing that sample quality is essentially important to clarify the characteristic features for the heavy fermion compounds.

    DOI: 10.1088/0034-4885/79/11/114501

    Web of Science

    Scopus

    researchmap

  • New heavy-fermion antiferromagnet UPd<inf>2</inf>Cd<inf>20</inf> 査読

    Yusuke Hirose, Hiroshi Doto, Fuminori Honda, Dexin Li, Dai Aoki, Yoshinori Haga, Rikio Settai

    Journal of Physics Condensed Matter   28 ( 42 )   2016年8月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2016 IOP Publishing Ltd. We succeeded in growing a new high quality single crystal of a ternary uranium compound UPd2Cd20. From the electrical resistivity, magnetization, magnetic susceptibility, and specific heat experiments, UPd2Cd20 is found to be an antiferromagnetic heavy-fermion compound with the Néel temperature = 5 K and exhibits the large electronic specific heat coefficient γ exceeding 500 mJ (K2• mol)-1. This compound is the first one that exhibits the magnetic ordering with the magnetic moments of the U atom in a series of UT2X20 (T: transition metal, X = Al, Zn, Cd). UPd2Cd20 shows typical characteristic features in heavy-fermion systems such as a broad maximum in the magnetic susceptibility at and a large coefficient A of T 2 term in the resistivity.

    DOI: 10.1088/0953-8984/28/42/425601

    Web of Science

    Scopus

    researchmap

  • First-order structural change accompanied by Yb valence transition in YbInCu<inf>4</inf> 査読

    Satoshi Tsutsui, Kunihisa Sugimoto, Ryoma Tsunoda, Yusuke Hirose, Takeshi Mito, Rikio Settai, Masaichiro Mizumaki

    Journal of the Physical Society of Japan   85 ( 6 )   2016年6月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    ©2016 The Physical Society of Japan. A diffraction experiment using high-energy X-rays was carried out on YbInCu4. Below the Yb valence transition temperature, the splitting of Bragg peaks was detected in high-order reflections. No superlattice reflections accompanying the valence ordering were found below the transition temperature. These experimental findings indicate that a structural change from a cubic structure to a tetragonal structure without valence ordering occurs at the transition temperature. Such a structural change free from any valence ordering is difficult to understand only in terms of Yb valence degrees of freedom. This means that the structural change may be related to electronic symmetries such as quadrupolar degrees of freedom as well as to the change in Yb valence.

    DOI: 10.7566/JPSJ.85.063602

    Web of Science

    Scopus

    researchmap

  • Test of spontaneous magnetization of non-centrosymmetric superconductor lairsi<inf>3</inf> 査読

    Daichi Kawakatsu, Akihiko Sumiyama, Jun Gouchi, Akira Yamaguchi, Gaku Motoyama, Yusuke Hirose, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   85 ( 2 )   2016年2月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2016 The Physical Society of Japan. The magnetization change ΔM at the superconducting transition of LaIrSi3 has been measured in various magnetic fields H. The observed ΔM in H = 0 is within the range of the Meissner effect induced by the possible residual field, suggesting that the spontaneous magnetization, if it exists, is below the experimental accuracy. This result is in agreement with the results of μSR experiments, in which no spontaneous magnetic field has been observed in the superconducting state.

    DOI: 10.7566/JPSJ.85.025002

    Web of Science

    Scopus

    researchmap

  • Specific heat in high magnetic fields and magnetic phase diagram of CePt2 In7 査読

    Y. Krupko, A. Demuer, S. Ota, Y. Hirose, R. Settai, I. Sheikin

    Physical Review B   93 ( 8 )   2016年2月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2016 American Physical Society. We report specific heat measurements on a high-quality single crystal of the heavy-fermion compound CePt2In7 in magnetic fields up to 27 T. The zero-field specific heat data above the Néel temperature, TN, suggest a moderately enhanced value of the electronic specific heat coefficient γ=180mJ/K2mol. For T<TN, the data at zero applied magnetic field are consistent with the existence of an anisotropic spin-density wave opening a gap on almost the entire Fermi surface, suggesting extreme two-dimensional electronic and magnetic structures for CePt2In7. TN is monotonically suppressed by magnetic field applied along the c axis. When a field is applied parallel to the a axis, TN first increases at low field up to about 10 T and then decreases monotonically at a higher field. The magnetic phase diagram based on specific heat measurements suggests that a field-induced quantum critical point is likely to occur slightly below 60 T for both principal orientations of the magnetic field.

    DOI: 10.1103/PhysRevB.93.085121

    Web of Science

    Scopus

    researchmap

  • Search for spontaneous magnetization in noncentrosymmetric superconductors 査読

    A. Sumiyama, D. Kawakatsu, J. Gouchi, I. Kawasaki, A. Yamaguchi, G. Motoyama, Y. Hirose, R. Settai, Y. Onuki

    Journal of Physics: Conference Series   683 ( 1 )   2016年2月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © Published under licence by IOP Publishing Ltd. We have measured the magnetization of two noncentrosymmetric superconductors: Ir2Ga9 and CePt3Si using a SQUID magnetometer, neither of which has been tested for the time-reversal symmetry in the superconducting state. For Ir2Ga9, the magnetization change ΔM below the superconducting transition temperature Tc ∼ 2.2 K was smaller than 10-5 G in zero magnetic field, suggesting that ΔM originates in the Meissner effect induced by the possible residual field. When CePt3Si was cooled in zero magnetic field, ΔM along the c axis first decreased below Tc+ ∼ 0.75 K (high-Tc phase) and then increased below Tc- ∼ 0.45 K (bulk superconducting phase). Since this behavior cannot be explained by the Meissner effect, it may be a sign of a spontaneous magnetization.

    DOI: 10.1088/1742-6596/683/1/012029

    Scopus

    researchmap

  • 19pBL-9 PrPt_2Cd_<20>の比熱測定による結晶場基底状態の研究

    竹内 徹也, 広瀬 雄介, 土塔 寛, 本多 史憲, 摂待 力生

    日本物理学会講演概要集   71   2013 - 2013   2016年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.71.1.0_2013

    CiNii Article

    CiNii Books

    researchmap

  • 22aBM-11 重い電子系反強磁性体CeAl_2の圧力下de Haas-van Alphen効果IV

    佐瀬 芳行, 広瀬 雄介, 本多 史憲, 青木 大, 摂待 力生

    日本物理学会講演概要集   71   2370 - 2370   2016年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.71.1.0_2370

    CiNii Article

    CiNii Books

    researchmap

  • 20pPSB-4 CeIr(In_<1-x>Cd_x)_5の強磁場磁化測定

    角田 竜馬, 広瀬 雄介, 松田 康弘, 金道 浩一, 摂待 力生

    日本物理学会講演概要集   71   2109 - 2109   2016年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.71.1.0_2109

    CiNii Article

    CiNii Books

    researchmap

  • 22aPS-47 新しい重い電子系反強磁性体UPd_2Cd_<20>の電子状態

    土塔 寛, 広瀬 雄介, 本多 史憲, 青木 大, 芳賀 芳範, 三宅 厚志, 徳永 将史, 摂待 力生

    日本物理学会講演概要集   71   2439 - 2439   2016年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.71.1.0_2439

    CiNii Article

    CiNii Books

    researchmap

  • 19pBL-8 PrPt_2Cd_<20>の強磁場磁化II

    広瀬 雄介, 土塔 寛, 摂待 力生, 竹内 徹也, 本多 史憲, 芳賀 芳範, 三宅 厚志, 徳永 将史, 吉澤 大智, 木田 孝則, 萩原 政幸, Aoki D.

    日本物理学会講演概要集   71   2012 - 2012   2016年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.71.1.0_2012

    CiNii Article

    CiNii Books

    researchmap

  • Crossover phase diagram and electronic state in the heavy-fermion metamagnets UIr<inf>2</inf>Zn<inf>20</inf> and UCo<inf>2</inf>Zn<inf>20</inf> 査読

    Yusuke Hirose, Tetsuya Takeuchi, Fuminori Honda, Shingo Yoshiuchi, Masayuki Hagiwara, Etsuji Yamamoto, Yoshinori Haga, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   84 ( 7 )   2015年7月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    ©2015 The Physical Society of Japan. Crossover phase diagrams in the magnetic field versus temperature (H-T) plane of the nonmagnetic heavy-fermion metamagnets UT2Zn20 (T:Ir, Co) are studied by measuring the magnetic and electronic transport properties. The crossover phase diagrams of UIr2Zn20 and UCo2Zn20 are composed of a low-magnetic-field region (LFR) and a high-magnetic-field region (HFR), which are characterized by magnetic properties and the Hall effect, respectively. The LFR is found to form a closed area in the H-T plane, which is a quite different feature from the conventional uranium heavy-fermion compounds and the first observation in uranium compounds. From the drastic anomaly in the Hall effect at a metamagnetic field of UIr2Zn20, it is found that the metamagnetic behavior in UIr2Zn20 corresponds to a crossover from the heavy-fermion state to the field-induced ferromagnetic or polarized paramagnetic state accompanied by the reconstruction or topology change of Fermi surfaces. In UCo2Zn20, on the other hand, no sign of abrupt change in the electronic state at the metamagnetic field is observed. These contrastive crossover phase diagrams and the electronic state changes at the metamagnetic field are due to the different hybridization strengths between the 5 f electrons of U atoms and the d electrons of Ir and Co atoms, leading to the differences in magnetic correlation and crystalline electric field ground state or the degree of itinerancy of 5 f electrons.

    DOI: 10.7566/JPSJ.84.074704

    Web of Science

    Scopus

    researchmap

  • Spontaneous magnetization of non-centrosymmetric superconductor LaNiC<inf>2</inf> 査読

    Akihiko Sumiyama, Daichi Kawakatsu, Jun Gouchi, Akira Yamaguchi, Gaku Motoyama, Yusuke Hirose, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   84 ( 1 )   2015年1月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2015 The Physical Society of Japan. We have measured the magnetization of single crystals of the non-centrosymmetric superconductor LaNiC2, which is considered to break time-reversal symmetry by μSR measurements. Below the transition temperature Tc ~3K, the emergence of magnetization on the order of 10-5G is observed in zero magnetic field along the c-axis but not along the a-axis. This spontaneous magnetization is larger than the Meissner effect induced by the possible residual field and did not change after applying magnetic fields of up to 15mOe or after warming to room temperature. The results that the direction is related to the lack of inversion symmetry and that the magnitude is sensitive to the crystallinity of the sample suggest some analogy with pyroelectricity.

    DOI: 10.7566/JPSJ.84.013702

    Web of Science

    Scopus

    researchmap

  • Single crystal growth and electronic state of UPd2Cd20 査読

    Hiroshi Doto, Yusuke Hirose, Fuminori Honda, Dexin Li, Yoshiya Homma, Dai Aoki, Rikio Settai

    20TH INTERNATIONAL CONFERENCE ON MAGNETISM, ICM 2015   75   56 - 61   2015年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:ELSEVIER SCIENCE BV  

    We succeeded in growing single crystals of UPd2Cd20 by the Cd self-flux method. This compound crystallizes in the cubic CeCr2Al20-type structure. From the low-temperature electrical resistivity and Kadowaki-Woods relation, the electronic specific heat coefficient. is estimated to be about 400 mJ/mol . K-2. The magnetic susceptibility of UPd2Cd20 indicates a broad maximum at 6.6 K and a rapid decrease at 5.0 K, which correspond to the formation of the heavy fermion state and the antiferromagnetic transition, respectively. These experimental results strongly suggest that UPd2Cd20 is a new heavy fermion antiferromagnet.

    DOI: 10.1016/j.phpro.2015.12.009

    Web of Science

    researchmap

  • Themal Expansion and Magnetostriction of YbAuCu<inf>4</inf> 査読

    Tetsuya Tkeuchi, Yusuke Hirose, Ryoma Tsunoda, Fuminori Honda, Rikio Settai

    Physics Procedia   75   460 - 467   2015年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2015 The Authors. Published by Elsevier B.V. Precise thermal expansion and magnetostriction measurements were performed on the heavyfermion compound YbAuCu4 in order to examine the crossover valence transition at TV which was proposed by the nuclear magnetic resonance measurements. The temperature dependence of the thermal expansion coefficient α under magnetic fields shows a broad peak, which shifts to higher temperatures with increasing magnetic fields. The corresponding linear thermal expansion Δℓ/ℓ parallel to the magnetic field of 7.0 T shows a marked decrease below about 10 K, indicating a contraction of sample length at low temperatures. These results are discussed in relation to the observed temperature dependence of the nuclear quadrupole frequency νQ under magnetic fields.

    DOI: 10.1016/j.phpro.2015.12.057

    Scopus

    researchmap

  • Single Crystal Growth and Electronic State of UPd<inf>2</inf>Cd<inf>20</inf> 査読

    Hiroshi Doto, Yusuke Hirose, Fuminori Honda, Dexin Li, Yoshiya Homma, Dai Aoki, Rikio Settai

    Physics Procedia   75   56 - 61   2015年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2015 The Authors. Published by Elsevier B.V. We succeeded in growing single crystals of UPd2Cd20 by the Cd self-flux method. This compound crystallizes in the cubic CeCr2Al20-type structure. From the low-temperature electrical resistivity and Kadowaki-Woods relation, the electronic specific heat coefficient γ is estimated to be about 400mJ/mol ·K2. The magnetic susceptibility of UPd2Cd20 indicates a broad max-imum at 6.6K and a rapid decrease at 5.0K, which correspond to the formation of the heavy fermion state and the antiferromagnetic transition, respectively. These experimental results strongly suggest that UPd2Cd20 is a new heavy fermion antiferromagnet.

    DOI: 10.1016/j.phpro.2015.12.009

    Scopus

    researchmap

  • Themal Expansion and Magnetostriction of YbAuCu4 査読

    Tetsuya Takeuchi, Yusuke Hirose, Ryoma Tsunoda, Fuminori Honda, Rikio Settai

    20TH INTERNATIONAL CONFERENCE ON MAGNETISM, ICM 2015   75   460 - 467   2015年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:ELSEVIER SCIENCE BV  

    Precise thermal expansion and magnetostriction measurements were performed on the heavy-fermion compound YbAuCu4 in order to examine the crossover valence transition at T-v which was proposed by the nuclear magnetic resonance measurements. The temperature dependence of the thermal expansion coefficient a under magnetic fields shows a broad peak, which shifts to higher temperatures with increasing magnetic fields. The corresponding linear thermal expansion Delta l/l parallel to the magnetic field of 7.0 T shows a marked decrease below about 10 K, indicating a contraction of sample length at low temperatures. These results are discussed in relation to the observed temperature dependence of the nuclear quadrupole frequency nu(Q) under magnetic fields.

    DOI: 10.1016/j.phpro.2015.12.057

    Web of Science

    researchmap

  • 21pBB-10 RPt_2Cd_<20>(R=Rare Earth)の単結晶育成と電子状態の研究

    土塔 寛, 広瀬 雄介, 本多 史憲, 李 徳新, 青木 大, 竹内 徹也, 芳賀 芳範, 摂待 力生

    日本物理学会講演概要集   70   2012 - 2012   2015年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.70.1.0_2012

    CiNii Article

    CiNii Books

    researchmap

  • 22aPS-55 高圧下におけるYbIr_2Zn_<20>のX線吸収測定

    本多 史憲, 広瀬 雄介, 水牧 仁一朗, 河村 直己, 筒井 智嗣, 石松 直樹, 綿貫 徹, 渡辺 真仁, 青木 大, 摂待 力生, 大貫 惇睦

    日本物理学会講演概要集   70   2147 - 2147   2015年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.70.1.0_2147

    CiNii Article

    CiNii Books

    researchmap

  • 22aPS-39 CeIr(In_<1-x>Cd_x)_5の圧力下電気抵抗測定

    角田 竜馬, 広瀬 雄介, 本多 史憲, 摂待 力生, 大貫 惇睦

    日本物理学会講演概要集   70   2132 - 2132   2015年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.70.1.0_2132

    CiNii Article

    CiNii Books

    researchmap

  • 17aPS-25 重い電子系反強磁性体CeAl_2の圧力下de Haas-van Alphen効果II

    佐瀬 芳行, 広瀬 雄介, 本多 史憲, 青木 大, 摂待 力生

    日本物理学会講演概要集   70   1821 - 1821   2015年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.70.2.0_1821

    CiNii Article

    CiNii Books

    researchmap

  • 17aPS-58 PrPt_2Cd_<20>の強磁場磁化

    広瀬 雄介, 土塔 寛, 摂待 力生, 竹内 徹也, 本多 史憲, 青木 大, 芳賀 芳範, 吉澤 大智, 木田 孝則, 杉山 清寛, 萩原 政幸

    日本物理学会講演概要集   70   1853 - 1853   2015年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.70.2.0_1853

    CiNii Article

    CiNii Books

    researchmap

  • 18pDA-12 UPd_2Cd_<20>の単結晶育成と電子状態の研究

    土塔 寛, 広瀬 雄介, 本多 史憲, 李 徳新, 本間 佳哉, 青木 大, 摂待 力生

    日本物理学会講演概要集   70   2034 - 2034   2015年

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人日本物理学会  

    DOI: 10.11316/jpsgaiyo.70.2.0_2034

    CiNii Article

    CiNii Books

    researchmap

  • Unique Fermi Surface and Emergence of Charge Density Wave in EuGa4 and EuAl4 査読

    Ai Nakamura, Yuichi Hiranaka, Masato Hedo, Takao Nakama, Yasunao Miura, Hiroki Tsutsumi, Akinobu Mori, Kazuhiro Ishida, Katsuya Mitamura, Yusuke Hirose, Kiyohiro Sugiyama, Fuminori Honda, Tetsuya Takeuchi, Tatsuma D. Matsuda, Etsuji Yamamoto, Yoshinori Haga, Yoshichika Onuki

    JPS Conference Proceedings, Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013)   3   011012-1 - 011012-6   2014年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.7566/JPSCP.3.011012

    researchmap

  • Field-Induced Order in Heavy-Fermion Compound YbCo2Zn20 査読

    Koji Kaneko, Stéphane Raymond, Eric Ressouche, Gerard Lapertot, Tetsuya Takeuchi, Yusuke Hirose, Fuminori Honda, Yoshichika Onuki

    JPS Conference Proceedings, Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013)   3   011061-1 - 011061-5   2014年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.7566/JPSCP.3.011061

    researchmap

  • Antiferromagnetic Order of EuGa4 Probed by Mössbauer Spectroscopy 査読

    Yoshiya Homma, Ai Nakamura, Yusuke Hirose, Masato Hedo, Takao Nakama, Dexin Li, Fuminori Honda, Yoshichika Ōnuki, Dai Aoki

    JPS Conference Proceedings, Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013)   3   011082-1 - 011082-6   2014年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.7566/JPSCP.3.011082

    researchmap

  • Fermi Surface and Magnetic Properties of Ferromagnet EuRu2P2 査読

    Masato Hedo, Yasunao Miura, Akinobu Mori, Hiroki Tsutsumi, Yusuke Hirose, Fuminori Honda, Tetsuya Takeuchi, Ai Nakamura, Yuichi Hiranaka, Takao Nakama, Hisatomo Harima, Yoshichika Onuki

    JPS Conference Proceedings, Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013)   3   011010-1 - 011010-8   2014年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.7566/JPSCP.3.011010

    researchmap

  • Precise Thermal Expansion Measurements on Heavy Fermion Compounds YbT2Zn20 (T: Co, Rh, Ir) 査読

    Tetsuya Takeuchi, Shingo Yoshiuchi, Yusuke Hirose, Fuminori Honda, Rikio Settai, Yoshichika Onuki

    JPS Conference Proceedings, Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013)   3   011017-1 - 011017-6   2014年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.7566/JPSCP.3.011017

    researchmap

  • Drastic Change of Electronic Properties in Ce2MgSi2 and CeNiIn4 under High Pressure 査読

    Fuminori Honda, Naohisa Yoshitani, Yusuke Hirose, Kazuhiro Ishida, Takashi Maeta, Atsushi Miyake, Shigeki Tanaka, Katsuya Shimizu, Tetsuya Takeuchi, Kazuyuki Matsubayashi, Yoshiya Uwatoko, Rikio Settai, Dai Aoki, Yoshichika Onuki

    JPS Conference Proceedings, Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013)   3   011082-1 - 011082-6   2014年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.7566/JPSCP.3.012026

    researchmap

  • Magnetic Properties of SmCd11 査読

    K. Sugiyama, K. Mitamura, Y. Hirose, T. Takeuchi, M. Hagiwara, Y. Onuki

    JPS Conference Proceedings   2014年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    researchmap

  • Novel electronic states of heavy fermion compound YbCo<inf>2</inf>Zn <inf>20</inf> 査読

    Fuminori Honda, Yuki Taga, Yusuke Hirose, Shingo Yoshiuchi, Yoshiharu Tomooka, Masahiro Ohya, Jyunya Sakaguchi, Tetsuya Takeuchi, Rikio Settai, Yasuyuki Shimura, Toshiro Sakakibara, Ilya Sheikin, Toshiki Tanaka, Yasunori Kubo, Yoshichika Onuki

    Journal of the Physical Society of Japan   83 ( 4 )   2014年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    We studied the heavy fermion compound YbCo2Zn20 with an electronic specific heat coefficient γ ≥ 8000 mJ/(K 2·mol) by measuring the de Haas-van Alphen (dHvA) oscillation, Hall effect, magnetic susceptibility, and magnetization at ambient pressure, as well as the electrical resistivity in magnetic fields of up to 320 kOe and at pressures of up to 5 GPa. The detected Fermi surfaces are small in volume, reflecting the small Brillouin zone based on the large cubic lattice constant a = 14.005 A. The cyclotron effective masses, which were determined from the dHvA experiment, are found to be markedly reduced in magnetic fields. In other words, the detected cyclotron masses of 2.2-8.9m0 (m0: the rest mass of an electron) at Hav = 117 kOe are enhanced to 100-500m0 at 0 kOe. By applying pressure, the heavy fermion state disappears at Pc ' 1.8 GPa and orders antiferromagnetically for P > Pc. The field-induced antiferroquadrupolar phase, which is observed only for H k h111i in the magnetic field range from HQ = 60 kOe to H0 Q = 210 kOe, is found to shift to lower magnetic fields and merge with theantiferromagnetic phase at 4.5 GPa. © 2014 The Physical Society of Japan.

    DOI: 10.7566/JPSJ.83.044703

    Web of Science

    Scopus

    researchmap

  • First-order antiferromagnetic transition and fermi surfaces in semimetal EuSn<inf>3</inf> 査読

    Akinobu Mori, Yasunao Miura, Hiroki Tsutsumi, Katsuya Mitamura, Masayuki Hagiwara, Kiyohiro Sugiyama, Yusuke Hirose, Fuminori Honda, Tetsuya Takeuchi, Ai Nakamura, Yuichi Hiranaka, Masato Hedo, Takao Nakama, Yoshichika Onuki

    Journal of the Physical Society of Japan   83 ( 2 )   2014年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    We grew high-quality single crystals of the antiferromagnet EuSn3 with the AuCu3-type cubic crystal structure by the Sn self-flux method and measured the electrical resistivity, magnetic susceptibility, high-field magnetization, specific heat, thermal expansion, and de Haas-van Alphen (dHvA) effect, in order to study the magnetic and Fermi surface properties. We observed steplike changes in the electrical resistivity and magnetic susceptibility, and a sharp peak of the specific heat and thermal expansion coefficient at a Néel temperature TN = 36.4 K. The first-order nature of the antiferromagnetic transition was ascertained by the observation of thermal hysteresis as well as of latent heat at TN. The present antiferromagnetic transition is found to be not a typical second-order phase transition but a first-order one. From the results of dHvA experiment, we clarified that the Fermi surface is very similar to that of the divalent compound YbSn3, mainly consisting of a nearly spherical hole Fermi surface and eight ellipsoidal electron Fermi surfaces. EuSn3 is possibly a compensated metal, and the occupation of a nearly spherical hole Fermi surface is 3.5% in its Brillouin zone, indicating that EuSn3 is a semimetal. © 2014 The Physical Society of Japan.

    DOI: 10.7566/JPSJ.83.024008

    Web of Science

    Scopus

    researchmap

  • Studies of Ga NMR in EuGa4 査読

    H. Niki, S. Nakamura, N. Higa, M. Yogi, Y. Hirose, Y. Onuki, H. Harima

    JPS Conf. Proc   3   011015/1 - 6   2014年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    researchmap

  • Anisotropy of the superconducting upper critical field and antiferromagnetism in pressure-induced superconductor CePt<inf>2</inf>In<inf>7</inf> 査読

    Shuhei Kurahashi, Shunpei Ota, Shun Tomaru, Yusuke Hirose, Rikio Settai

    Journal of Physics: Conference Series   592 ( 1 )   2014年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    CePt2In7 is an antiferromagnet with TN =5.4K, which shows pressure-induced superconductivity at transition temperature Tc= 2.1 K around a critical pressure Pc =3.2 GPa. We have investigated an anisotropy of the superconducting upper critical field Hc2 in CePt2In7, which posesses two-dimensional tetragonal crystal structure and cylindrical Fermi surfaces elongated along c-axis. At 2.60 GPa, initial slope of Hc2 for H ∥ [001] is smaller than that for H ∥ [100], reflecting the two-dimensional Fermi surface of CePt2In7. However, Pauli paramagnetic suppression is strong for H ∥ [100] compared with that for H ∥ [001] in high magnetic field, and Hc2 (0) for H ∥ [001] seems to be larger than that for H ∥ [100] at 2.60 GPa in CePt2In7.

    DOI: 10.1088/1742-6596/592/1/012006

    Web of Science

    Scopus

    researchmap

  • Development of non-metallic diamond anvil cell and quantum oscillation measurement of CePt<inf>2</inf>ln<inf>7</inf> in a pulsed-magnet 査読

    Atsushi Miyake, Yoshimitsu Kohama, Shunpei Ohta, Yusuke Hirose, Rikio Settai, Kazuyuki Matsubayashi, Yoshiya Uwatoko, Akira Matsuo, Koichi Kindo, Masashi Tokunaga

    Journal of Physics: Conference Series   592 ( 1 )   2014年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    In order to combine the extreme conditions of high pressure and magnetic field, we have developed a non-metallic diamond anvil cell to avoid Joule-heating in a pulsed-magnetic field. Although the cell is deformed with loading, a maximum pressure of ∼ 8.5 GPa can be applied. Quantum oscillation measurements using tunnel diode oscillator have been performed for heavy fermion antiferromagnet CePt2In7 in a pulsed field and at ambient pressure. The detail of the pressure cell and field-induced Fermi surface changes of CePt2In7 are discussed.

    DOI: 10.1088/1742-6596/592/1/012149

    Web of Science

    Scopus

    researchmap

  • X-ray absorption spectroscopy and novel electronic properties in heavy fermion compounds YbT<inf>2</inf>Zn<inf>20</inf> (T: Rh and Ir) 査読

    Fuminori Honda, Yusuke Hirose, Atsushi Miyake, Masaichiro Mizumaki, Naomi Kawamura, Satoshi Tsutsui, Tetsu Watanuki, Shinji Watanabe, Tetsuya Takeuchi, Rikio Settai, Dai Aoki, Yoshichika O'Nuki

    Journal of Physics: Conference Series   592 ( 1 )   2014年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    YbT2Zn20 (T: Rh and Ir), which crystallizes in the cubic CeCr2Al20-type structure, is a member of the well-known heavy fermion compounds, indicating a huge electronic specific heat coefficient γ ≃ 500 mJ/(K2·mol). We have measured temperature and magnetic field dependences of Yb valence in YbT2Zn20 (T: Rh and Ir) at ambient pressure by the Lm edge x- ray absorption spectroscopy in order to investigate the valence state of Yb 4f electrons in these compounds. It is revealed that the Yb valence in both compounds significantly decreases with temperature below about 100 K and increases with increasing magnetic field at low temperatures in contrast to the case of YbCo2Zn20.

    DOI: 10.1088/1742-6596/592/1/012021

    Web of Science

    Scopus

    researchmap

  • Single crystal growth and magnetic properties of RCu<inf>9</inf>Sn<inf>4</inf> (R: Rare earth metals) 査読

    Yusuke Hirose, Shun Tomaru, Shoko Satoh, Shunpei Ota, Shuhei Kurahashi, Tetsuya Takeuchi, Fuminori Honda, Yoshiya Homma, Dexin Li, Dai Aoki, Rikio Settai

    Journal of Physics: Conference Series   592 ( 1 )   2014年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We succeeded in growing single crystals of tetragonal RCu9Sn4 (R=La, Ce, Pr, and Eu) by the Sn-self-flux method for the first time, and studied the electrical and magnetic properties of these compounds. The magnetism of CeCu9Sn4 and PrCu9Sn4 indicates an Ising anisotropy with the magnetic easy axis parallel to the [001] direction. We revealed that EuCu9Sn4 shows an antiferromagnetic transition with an easy plane type magnetic anisotropy in the present single crystal study.

    DOI: 10.1088/1742-6596/592/1/012034

    Web of Science

    Scopus

    researchmap

  • Fermi surface and magnetic properties of antiferromagnet EuBi<inf>3</inf> 査読

    Ai Nakamura, Yuichi Hiranaka, Masato Hedo, Takao Nakama, Yasutomi Tatetsu, Takahiro Maehira, Yasunao Miura, Akinobu Mori, Hiroki Tsutsumi, Yusuke Hirose, Katsuya Mitamura, Kiyohiro Sugiyama, Masayuki Hagiwara, Fuminori Honda, Tetsuya Takeuchi, Yoshinori Haga, Kazuyuki Matsubayashi, Yoshiya Uwatoko, Yoshichika Onuki

    Journal of the Physical Society of Japan   82 ( 12 )   2013年12月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    EuBi3 with the AuCu3-type cubic structure is known to be a Eu-divalent antiferromagnet with the Néel temperature TN ∼ 7:5 K. We succeeded in growing a high-quality single crystal by the Bi self-flux method. The magnetization at 1.3K for the magnetic field along the h100i direction increases linearly as a function of magnetic field, and saturates at a critical field Hc = 225 kOe, reaching a saturated magnetic moment of 7μB/Eu. Hc is well explained by the magnetic exchange interaction based on a two-sublattice model, using the simple relation Hc = (kB/3μB)(TN- θp) namely, Hc [kOe= 4:9 (TN - θp) [K], where θp is the paramagnetic Curie temperature θp = -36 K. The present antiferromagnetic state is found to be stable under pressures up to 8 GPa, where the Néel temperature increases with increasing pressure, being TN = 16:5K at 8 GPa. From the results of de Haas-van Alphen experiments on EuBiT3 and energy band calculations for the non-4f reference compound SrBi3, the Fermi surface is found to consist of three types of nearly spherical Fermi surfaces. © 2013 The Physical Society of Japan.

    DOI: 10.7566/JPSJ.82.124708

    Web of Science

    Scopus

    researchmap

  • Magnetic and fermi surface properties of EuGa<inf>4</inf> 査読

    Ai Nakamura, Yuichi Hiranaka, Masato Hedo, Takao Nakama, Yasunao Miura, Hiroki Tsutsumi, Akinobu Mori, Kazuhiro Ishida, Katsuya Mitamura, Yusuke Hirose, Kiyohiro Sugiyama, Fuminori Honda, Rikio Settai, Tetsuya Takeuchi, Masayuki Hagiwara, Tatsuma D. Matsuda, Etsuji Yamamoto, Yoshinori Haga, Kazuyuki Matsubayashi, Yoshiya Uwatoko, Hisatomo Harima, Yoshichika Onuki

    Journal of the Physical Society of Japan   82 ( 10 )   2013年10月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    We grew a high-quality single crystal EuGa4 with the tetragonal structure by the Ga self-flux method, and measured the electrical resistivity, magnetic susceptibility, high-field magnetization, specific heat, thermoelectric power and de Haas-van Alphen (dHvA) effect, together with the electrical resistivity and thermoelectric power under pressure. EuGa4 is found to be a Eu-divalent compound without anisotropy of the magnetic susceptibility in the paramagnetic state and to reveal the same magnetization curve between H ∥ [100] and [001] in the antiferromagnetic state, where the antiferromagnetic easy-axis is oriented along the [100] direction below a Néel temperature TN = 16:5 K. The magnetization curve is discussed on the basis of a simple two-sublattice model. The Fermi surface in the paramagnetic state was clarified from the results of a dHvA experiment for EuGa4 and an energy band calculation for a non-4f reference compound SrGa4, which consists of a small ellipsoidal hole-Fermi surface and a compensated cube-like electron-Fermi surface with vacant space in center. We observed an anomaly in the temperature dependence of the electrical resistivity and thermoelectric power at TCDW = 150K under 2 GPa. This might correspond to an emergence of the charge density wave (CDW). The similar phenomenon was also observed in EuAl4 at ambient pressure. We discussed the CDW phenomenon on the basis of the present peculiar Fermi surfaces. © 2013 The Physical Society of Japan.

    DOI: 10.7566/JPSJ.82.104703

    Web of Science

    Scopus

    researchmap

  • <sup>153</sup>Eu and <sup>69;71</sup>Ga zero-field nmr study of antiferromagnetic state in EuGa<inf>4</inf> 査読

    Mamoru Yogi, Saori Nakamura, Nonoka Higa, Haruo Niki, Yusuke Hirose, Yoshichika Onuki, Hisatomo Harima

    Journal of the Physical Society of Japan   82 ( 10 )   2013年10月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    We report 153Eu and 69;71Ga NMR under a zero magnetic field on the antiferromagnetic state of EuGa4 with TN ≈ 16 K. We have successfully observed a 153Eu zero-field NMR signal with well-resolved nuclear quadrupole splitting in the antiferromagnetic state of EuGa4. 69;71Ga zero-field NMR spectra were also observed below TN. The internal field and nuclear quadrupole frequency are estimated from a simulation of the spectra by the exact diagonalization of the nuclear spin Hamiltonian matrix. The asymmetrically split zero-field NMR spectra were explained by considering a configuration of the magnetic moments of Eu2+ lying in the basal ab-plane. The temperature dependence of the internal field, which is proportional to the sublattice magnetization, can be explained by the Brillouin function with J = S = 7/2. © 2013 The Physical Society of Japan.

    DOI: 10.7566/JPSJ.82.103701

    Web of Science

    Scopus

    researchmap

  • Heavy fermion state based on the kondo effect in EuNi<inf>2</inf>P <inf>2</inf> 査読

    Yuichi Hiranaka, Ai Nakamura, Masato Hedo, Tetsuya Takeuchi, Akinobu Mori, Yusuke Hirose, Katsuya Mitamura, Kiyohiro Sugiyama, Masayuki Hagiwara, Takao Nakama, Yoshichika Onuki

    Journal of the Physical Society of Japan   82 ( 8 )   2013年8月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    EuNi2P2 is known as a heavy fermion compound with an electronic specific heat coefficient γ = 100 mJ/(K2·mol) . We grew single crystals and studied their electronic and magnetic properties by measuring the electrical resistivity, magnetic susceptibility, high-field magnetization, specific heat, and thermal expansion. The present heavy fermion state is clarified to be based on the Kondo effect as in CeRu2Si2, revealing an intensive shrinkage of the volume below about 100K in the temperature dependence of thermal expansion. The temperature dependences of the 4f -electron contribution to the volume thermal expansion ΔV/V) 4f and the average Eu valence are found to show good scaling in EuNi2P2. © 2013 The Physical Society of Japan.

    DOI: 10.7566/JPSJ.82.083708

    Web of Science

    Scopus

    researchmap

  • Metamagnetic behavior and effect of pressure on the electronic state in heavy-fermion compound YbRh<inf>2</inf>Zn<inf>20</inf> 査読

    Fuminori Honda, Tetsuya Takeuchi, Shinichi Yasui, Yuki Taga, Shingo Yoshiuchi, Yusuke Hirose, Yoshiharu Tomooka, Kiyohiro Sugiyama, Masayuki Hagiwara, Koichi Kindo, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   82 ( 8 )   2013年8月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    We measured the magnetic susceptibility, high-field magnetization, magnetoresistance, specific heat, and Hall coefficient, together with the electrical resistivity under high pressures and magnetic fields, for the heavy-fermion compound YbRh2Zn20 with the cubic CeCr 2Al20-type structure. The metamagnetic behavior was observed at Hm =65 kOe for the magnetic field along the h100i direction below Txmax = 5:3 K, at which the temperature of the magnetic susceptibility indicates a broad maximum. The coefficient A of the T2 dependence of electrical resistivity ρ = ρ0 + AT2 and the electronic specific heat coefficient C=T possess a broad maximum at Hm. The metamagnetic field Hm is found to decrease with increasing pressure and to become zero at a critical pressure Pc ≠ 5:2 GPa. Correspondingly, the A value increases drastically in magnitude, and the Fermi liquid relation is no longer satisfied at 5.2 GPa in zero magnetic field, implying a non-Fermi liquid state. On the other hand, at magnetic fields ofH >20 kOe, the low-temperature resistivity exhibits a T2 dependence even at 5.2 GPa. The A coefficient decreases rapidly with increasing magnetic field. These results indicate that an electronic state at 5.2 GPa corresponds to the quantum critical point. © 2013 The Physical Society of Japan.

    DOI: 10.7566/JPSJ.82.084705

    Web of Science

    Scopus

    researchmap

  • Magnetism and superconductivity in CeCu <inf>2</inf> Ge <inf>2</inf> under high pressures and magnetic fields 査読

    Fuminori Honda, Takashi Maeta, Yusuke Hirose, Yoshichika Ōnuki, Atsushi Miyake, Rikio Settai

    Journal of the Korean Physical Society   63 ( 3 )   345 - 348   2013年8月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    We measured the electrical resistivity of CeCu 2 Ge 2 under various high pressures and strong magnetic fields. Beyond the previous antiferromagnetic critical pressure P c ≃ 8 GPa, the antiferromagnetic phase is found to exist at much higher pressure of 10.9 GPa even in magnetic fields up to 8 T. The pressure vs. temperature phase diagram and the magnetic field vs. temperature phase diagram under high pressure were constructed. The pressure-induced antiferromagnetic phase is still observed and coexists with pressure-induced superconductivity at 10.9 GPa. © 2013 The Korean Physical Society.

    DOI: 10.3938/jkps.63.345

    Web of Science

    Scopus

    researchmap

  • Effect of pressure on the field-induced ordered phase in the heavy-fermion compound YbCo <inf>2</inf> Zn <inf>20</inf> 査読

    Tetsuya Takeuchi, Yuki Taga, Shingo Yoshiuchi, Masahiro Ohya, Yusuke Hirose, Fuminori Honda, Rikio Settai, Yoshichika Ōnuki

    Journal of the Korean Physical Society   62 ( 12 )   1852 - 1854   2013年7月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    The effect of pressure on the field-induced ordered phase for H {norm of matrix} 〈111〉 in the heavy-fermion compound YbCo 2 Zn 20 , which is presumably a field-induced antiferro-quadrupolar (FI-AFQ) phase, was investigated in the pressure range up to 4.5 GPa and under magnetic fields up to 80 kOe. When pressure is applied, the metamagnetic-like transition at H m =6 kOe shifts to lower fields and disappears around the quantum critical pressure P c ∼1.8 GPa. A pressure-induced antiferromagnetic (PI-AFM) phase appears at pressures above about 2 GPa, and the critical field H c of the PI-AFM phase increases with increasing pressure. On the other hand, the transition field H Q of the FI-AFQ phase decreases gradually without showing any anomalous behavior around P c and becomes obscure around 4 GPa, where H c of the PI-AFM phase and H Q of the FI-AFQ phase become comparable. The magnetic field versus pressure, H-P, phase diagram for H {norm of matrix} 〈111〉 at 0.1 K was constructed in the pressure range up to 4.5 GPa. © 2013 The Korean Physical Society.

    DOI: 10.3938/jkps.62.1852

    Web of Science

    Scopus

    researchmap

  • Single crystal growth and various electronic states in Yb-based compounds 査読

    Yusuke Hirose, Shingo Yoshiuchi, Naoto Nishimura, Junya Sakaguchi, Kentaro Enoki, Ken Iwakawa, Yasunao Miura, Kiyohiro Sugiyama, Yoshichika Ōnuki, Rikio Settai, Tetsuya Takeuchi, Fuminori Honda, Tatsuma D. Matsuda, Etsuji Ymamoto, Yoshinori Haga, Masayuki Hagiwara

    Journal of the Korean Physical Society   62 ( 12 )   1858 - 1861   2013年7月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    We succeeded in growing single crystals of YbTIn 5 (T: Co, Rh, Ir), YbGa 4 , YbT 2 Zn 20 (T: Co, Rh, Ir), YbPdGe, Yb 2 Pt 2 Pb, and YbPd 5 Al 2 . The electronic and magnetic properties are clarified by measuring the electrical resistivity, magnetic susceptibility, magnetization, specific heat and de Haas - van Alphen effect. © 2013 The Korean Physical Society.

    DOI: 10.3938/jkps.62.1858

    Web of Science

    Scopus

    researchmap

  • Electronic states in antiferromagnet UCd<inf>11</inf> and reference compound ThCd<inf>11</inf>: Studied by the de Haas-van Alphen effect 査読

    Yusuke Hirose, Yasunao Miura, Hiroki Tsutsumi, Shingo Yoshiuchi, Masahiro Ohya, Kiyohiro Sugiyama, Tetsuya Takeuchi, Hiroshi Yamagami, Etsuji Yamamoto, Yoshinori Haga, Rikio Settai, Yoshichika Onuki

    Physica Status Solidi (B) Basic Research   250 ( 3 )   642 - 645   2013年3月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    We carried out the de Haas-van Alphen (dHvA) experiment for an antiferromagnet UCd11 and its non-5f reference compound ThCd11 to clarify the Fermi surface properties and the true electronic specific-heat coefficient γ of UCd11. We observed dHvA signals of both compounds and compared the experimental results with the result of theoretical band calculations. The Fermi surfaces of both compounds are found to be small and closed. The cyclotron masses obtained from the dHvA data of UCd11 are compared with those of reference compounds ThCd11, NpCd11, and LaCd11, and the γ value of UCd11 is estimated to be about 100mJK-2mol-1, which is much smaller than the 840mJK-2mol-1 in the previous reports. It is concluded that this large value is mainly not due to heavy quasiparticles but due to the magnetic contribution to the specific heat. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

    DOI: 10.1002/pssb.201200765

    Web of Science

    Scopus

    researchmap

  • Fermi surface and superconducting properties of non-centrosymmetric LaNiC <inf>2</inf> 査読

    Yusuke Hirose, Toshihiko Kishino, Jyunya Sakaguchi, Yasunao Miura, Fuminori Honda, Tetsuya Takeuchi, Etsuji Yamamoto, Yoshinori Haga, Hisatomo Harima, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( 11 )   2012年11月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    We succeeded in growing single crystals of LaNiC 2 with the non-centrosymmetric orthorhombic structure by the Czochralski method, and measured the electrical resistivity, de Haas-van Alphen effect, and specific heat to clarify the Fermi surface and superconducting properties. This compound has been studied from a viewpoint of the triplet superconducting pairing state. In the present experiment, we observed an ellipsoidal Fermi surface and a multiply-connected-pillar Fermi surface, which are split into two Fermi surfaces, reflecting the antisymmetric spin-orbit interaction based on the non-centrosymmetric crystal structure. The two ellipsoidal Fermi surfaces are split by 230 K, for example. The anisotropy of electrical resistivity and upper critical field H c2 in superconductivity are not large for three principal directions. From the low-temperature specific heat measurement, superconductivity in LaNiC 2 is explained by the framework of the BCS-superconductivity, contrary to the above arguments. The upper critical field H c2(0), which was obtained from the specific heat under magnetic fields, is about 2kOe. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJ.81.113703

    Web of Science

    Scopus

    researchmap

  • Heavy fermion state in antiferromagnet UCd<inf>11</inf> 査読

    Etsuji Yamamoto, Yusuke Hirose, Kentaro Enoki, Katsuya Mitamura, Kiyohiro Sugiyama, Tetsuya Takeuchi, Masayuki Hagiwara, Koichi Kindo, Yoshinori Haga, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We grew single crystals of an antiferromagnetic heavy-fermion compound UCd11 and a reference compound ThCd11, and carried out the magnetic susceptibility, high-field magnetization, and specific heat measurements in order to get more insight into the heavy fermion state which is realized in the antiferromagnetic state. The specific heat results suggest that the crystalline electric field (CEF) ground state of UCd11 is a doublet and the total splitting energy of the CEF scheme is less than 100 K. The H - T phase diagram for H ∥ <100> is approximately reproduced in the present experiments. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB023

    Web of Science

    Scopus

    researchmap

  • Characteristic electronic state in quasicrystal approximants RCd <inf>6</inf> (R:Rare Earth) 査読

    Akinobu Mori, Hisashi Ota, Shingo Yoshiuchi, Ken Iwakawa, Yuki Taga, Yusuke Hirose, Tetsuya Takeuchi, Etsuji Yamamoto, Yoshinori Haga, Fuminori Honda, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We measured the electrical resistivity, magnetic susceptibility, and specific heat in quasicrystal approximants RCd6. It was confirmed that the structural order-disorder transition of a tetrahedron with 4Cd atoms occurs at about 160 K when the lattice constant a is longer than a = 15.481 Å in YCd6, namely for RCd6 (R: Y, Pr, Nd, Sm, Gd, Tb, Dy and Yb ). The structural transition is found to have a great influence on the low-temperature electrical resistivity. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB019

    Web of Science

    Scopus

    researchmap

  • Multiple metamagnetic transitions in antiferromagnet Yb<inf>2</inf>Pt <inf>2</inf>Pb with the shastry-sutherland lattice 査読

    Ken Iwakawa, Yusuke Hirose, Kentaro Enoki, Kiyohiro Sugiyama, Tetsuya Takeuchi, Fuminori Honda, Masayuki Hagiwara, Koichi Kindo, Takehito Nakano, Yasuo Nozue, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    From the magnetization and magnetoresistance measurements, we constructed the magnetic phase diagram of Yb2Pt2Pb with the Shastry-Sutherland lattice, which consists of characteristic two phases below 1 K with many metamagnetic transitions, revealing magnetic frustrations. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB058

    Web of Science

    Scopus

    researchmap

  • Electronic and magnetic properties in heavy fermion ferromagnet YbPdGe 査読

    Kentaro Enoki, Yusuke Hirose, Shingo Yoshiuchi, Kiyohiro Sugiyama, Fuminori Honda, Tetsuya Takeuchi, Etsuji Yamamoto, Yoshinori Haga, Masayuki Hagiwara, Koichi Kindo, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    The crystal structure of YbPdGe is orthorhombic, with a large lattice constant for the b-axis. Reflecting this crystal structure, the electronic state is well conductive in the a-c plane. Magnetically YbPdGe is a ferromagnet with a Curie temperature TC = 11.4 K, and ferromagnetic moments are most likely oriented along the b-axis. The electronic specific heat coefficient γ = 150 mJ/(K2· mol) and a reduced magnetic entropy at TC suggest that YbPdGe is a heavy fermion ferromagnet. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB056

    Web of Science

    Scopus

    researchmap

  • Quantum criticality and heavy fermion state in YbCo<inf>2</inf>Zn <inf>20</inf> under pressure and magnetic field 査読

    Yuki Taga, Shingo Yoshiuchi, Masahiro Ohya, Jyunya Sakaguchi, Yusuke Hirose, Fuminori Honda, Tetsuya Takeuchi, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We studied an effect of pressure on the heavy fermion state of YbCo 2Zn20 under magnetic fields. The critical pressure P c, where the electronic state changes from the heavy fermion state to the antiferromagnetic state, is estimated to be Pc≃1.8 GPa. The super-heavy fermion state in the Pc region is found to be strongly destroyed in magnetic fields for H ∥<100>. The field-induced quadrupolar phase, which is most likely realized only for H ∥<100>, is found to be robust even in the antiferromagnetic pressure region. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB064

    Web of Science

    Scopus

    researchmap

  • Electrical and magnetic properties of new Yb-based compound YbPd <inf>5</inf>Al<inf>2</inf> 査読

    Yusuke Hirose, Naoto Nishimura, Kentaro Enoki, Fuminori Honda, Tetsuya Takeuchi, Kiyohiro Sugiyama, Masahiro Hagiwara, Koichi Kindo, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We succeeded in growing a single crystal of YbPd5Al2 with the tetragonal structure. The temperature dependence of electrical resistivity and a small value of the coefficient A in the Fermi liquid relation ρ = ρ0 + AT2 suggest that the 4 f -electrons are well localized. A magnetic ordering was found at To = 0.19 K in the specific heat measurement. On the other hand, the magnetic entropy exhibits only 0.5R ln 2 at To, and the specific heat shows a long tail above To. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB057

    Web of Science

    Scopus

    researchmap

  • De Haas-van alphen effect and fermi surface properties in YbTIn<inf>5</inf> (T : Co, Rh, Ir) and YbCoGa<inf>5</inf> 査読

    Jyunya Sakaguchi, Hiroki Tsutsumi, Yusuke Hirose, Yasunao Miura, Fuminori Honda, Hisatomo Harima, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We measured the de Haas-van Alphen oscillation in divalent compounds YbTIn5 (T : Co, Rh, Ir) and YbCoGa5. The Fermi surfaces, which are characteristic in two kinds of nearly cylindrical Fermi surface, are approximately unchanged in these compounds and are well explained by the results of energy band calculations. The cyclotron mass is found to increase remarkably as the average lattice constant decreases from 5.4 Å in YbIrIn 5 to 5.2 Å in YbCoGa5: m*c = 1.1m0 in YbIrIn5 and 5.1m0 in YbCoGa 5 for dHvA branch β1, revealing a chemical pressure effect. There exists the hybridization between 4 f electrons and conduction electrons in YbCoGa5. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB059

    Web of Science

    Scopus

    researchmap

  • Pressure-induced super heavy fermion state and antiferromagnetism in YbIr<inf>2</inf>Zn<inf>20</inf> 査読

    Fuminori Honda, Yuki Taga, Shinichi Yasui, Shingo Yoshiuchi, Yusuke Hirose, Tetsuya Takeuchi, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We studied an effect of pressure on the electronic state of YbIr 2Zn20under magnetic fields. The heavy fermion state at ambient pressure is found to be changed into an antiferromagnetic state at pressures larger than a critical pressure Pc≃ 5.2 GPa, where the electronic state indicates a superheavy fermion state with an order of the electronic specific specific heat coefficient γ = 20 J/(K 2·mol). The temperature dependence of the electrical resistivity shows a characteristic two-peak structure above 5.0 GPa, implying the combined phenomena between the Kondo effect and the crystalline electric field effect. At 7.6 GPa, the magnetoresistance shows a broad maximum at a critical field Hc, corresponding to a pressure-induced antiferromagnetic phase with the Néel temperature TN = 1.4 K. TN increases with further increasing pressure. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB063

    Web of Science

    Scopus

    researchmap

  • Antiferromagnetic heavy fermion state in CeAl<inf>3</inf> 査読

    Kazuhiro Ishida, Yuki Taga, Yusuke Hirose, Ken Iwakawa, Akinobu Mori, Fuminori Honda, Tetsuya Takeuchi, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We measured the electrical resistivity of a prototype heavy fermion antiferromagnet CeAl3 in the temperature range from 0.1 K to room temperature under various magnetic fields and pressures. The heavy fermion state at ambient pressure is drastically destroyed under a small pressure and magnetic field. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB053

    Web of Science

    Scopus

    researchmap

  • Magnetic properties of RIr<inf>2</inf>Zn<inf>20</inf> (R : Rare Earth) with the caged structure 査読

    Yuki Taga, Kiyohiro Sugiyama, Kentaro Enoki, Yusuke Hirose, Ken Iwakawa, Akinobu Mori, Kazuhiro Ishida, Tetsuya Takeuchi, Masayuki Hagiwara, Koichi Kindo, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    Néel temperatures in RIr2Zn20 (R : rare earth) with the cubic caged structure are found to be very low, which are below T N=5.0 K for GdIr2Zn20. This is mainly due to the long R-R distance and R atoms are spherically surrounded by Zn atoms. The corresponding crystalline electric field (CEF) splitting energies are also small, being below 100 K. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB051

    Web of Science

    Scopus

    researchmap

  • Collapse and enhancement of the heavy fermion state in CeCu<inf>6</inf> under magnetic field and pressure 査読

    Yusuke Hirose, Jyunya Sakaguchi, Masahiro Ohya, Masaki Matsushita, Fuminori Honda, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( SUPPL.B )   2012年9月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We measured the electrical resistivity under magnetic field and pressure and de Haas van Alphen (dHvA) oscillations in CeCu6. The A value in the Fermi liquid relation of the electrical resistivity ρ = ρ0 + AT 2 and the cyclotron effective mass are reduced with increasing magnetic fields and pressures. The A value, however, becomes distinct and/or is enhanced at the metamagnetic field, especially, in a characteristic pressure region where the electronic state deviates from the heavy fermion state, for example, at 2.00 GPa. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.81SB.SB009

    Web of Science

    Scopus

    researchmap

  • Electrical and magnetic properties of quasicrystal approximants RCd <inf>6</inf> (R: Rare earth) 査読

    Akinobu Mori, Hisashi Ota, Shingo Yoshiuchi, Ken Iwakawa, Yuki Taga, Yusuke Hirose, Tetsuya Takeuchi, Etsuji Yamamoto, Yoshinori Haga, Fuminori Honda, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   81 ( 2 )   2012年2月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    We measured the electrical resistivity, magnetic susceptibility, magnetization, and specific heat of the quasicrystal approximants RCd 6 (R: rare earth, Y-Lu) with a body-centered cubic (bcc) crystal structure. Single crystals were grown by the Cd-self flux method and annealing method. We confirmed that the structural order-disorder transition is realized at about 160K when the lattice constant a is larger than 15.481 A in YCd 6, namely, for R = Pr, Nd, Sm, Gd, Tb, Dy, and Yb. At lower temperatures, RCd 6 compounds, except non-4f reference compounds YCd6 and LuCd 6, and a divalent compound YbCd 6, are found to order antiferromagnetically. We clarified that the structural order-disorder transition has a great influence on the magnetic ordering and transport properties. The Néel temperature of RCd 6 (R: Nd, Sm, Tb, and Dy) with the structural order-disorder transition is appreciably higher than the de Gennes scaling normalized by the Néel temperature of GdCd 6, while the the Néel temperature of RCd 6 (R: Ho, Er, and Tm) without the structural transition approximately follows the de Gennes scaling. Moreover, the electrical resistivity of RCd 6 with the structural transition decreases monotonically below the Néel temperature, while it increases below the Néel temperature and a large residual resistivity remains at low temperatures in RCd 6 without the structural transition. The contribution of an Einstein oscillator to the phonon specific heat is also discussed in YCd 6 and LuCd 6. © 2012 The Physical Society of Japan.

    DOI: 10.1143/JPSJ.81.024720

    Web of Science

    Scopus

    researchmap

  • Pressure-induced novel superconductivity and heavy fermion state in rare earth compounds 査読

    Fuminori Honda, Yusuke Hirose, Shingo Yoshiuchi, Shinichi Yasui, Tetsuya Takeuchi, Ismardo Bonalde, Katsuya Shimizu, Rikio Settai, Yoshichika Onuki

    Journal of Physics: Conference Series   400 ( PART 2 )   2012年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We have carried out the electrical resistivity measurements under high pressures up to 24 GPa for CeTX3 (T: Co and Ir, X: Si and Ge), CePd5Al2 and YbIr2Zn20 in order to investigate quantum criticality and superconductivity. Antiferromagnets CeTX3 with the non-centrosymmetric tetragonal structure show superconductivity under high pressures and reveal a huge upper critical field for H∥ [001]. An antiferromagnet CePd5Al2, which is an isostructural family of a heavy fermion superconductor NpPd5Al 2, also shows superconductivity under high pressures. In these compounds, superconductivity appears in the vicinity of quantum critical point. On the other hand, YbIr2Zn20 without magnetic ordering approaches to the quantum critical point with increasing pressure and exhibits a super-heavy fermion state exceeding 10 J/(K2· mol). © Published under licence by IOP Publishing Ltd.

    DOI: 10.1088/1742-6596/400/2/022028

    Web of Science

    Scopus

    researchmap

  • Metamagnetic behavior in heavy fermion compounds UCo<inf>2</inf>Zn <inf>20</inf> and UIr<inf>2</inf>Zn<inf>20</inf> 査読

    Y. Hirose, K. Enoki, S. Yoshiuchi, T. Takeuchi, F. Honda, K. Sugiyama, E. Yamamoto, Y. Haga, M. Hagiwara, K. Kindo, R. Settai, Y. Onuki

    Journal of Physics: Conference Series   391 ( 1 )   2012年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    The metamagnetic behavior, which is typical in heavy fermion compounds, is observed in UCo2Zn20 and UIr2Zn20 at Hm = 80 and 20 kOe, respectively. Reflecting the metamagnetic behavior, the magnetoresistance is suppressed in magnetic fields larger than Hm, and the corresponding A-value of a Fermi liquid relation in the electrical resistivity ρ ρ0+AT2 indicates a peak at around Hm. Pressure suppresses this behavior in UIr2Zn20. © Published under licence by IOP Publishing Ltd.

    DOI: 10.1088/1742-6596/391/1/012021

    Web of Science

    Scopus

    researchmap

  • Characteristic magnetic phase diagram in heavy-fermion compound YbCo <inf>2</inf>Zn<inf>20</inf> 査読

    T. Takeuchi, S. Yoshiuchi, M. Ohya, M. Matsushita, S. Yasui, Y. Hirose, K. Sugiyama, F. Honda, R. Settai, Y. Onuki

    Journal of Physics: Conference Series   391 ( 1 )   2012年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We studied the magnetic field versus temperature phase diagram of the heavy-fermion compound YbCo2Zn20 with the cubic CeCr2Al20-type structure by measuring the specific heat, ac-susceptibility, and electrical resistivity under magnetic fields. In a low magnetic field region, a metamagnetic behavior was observed at Hm 6 kOe for three principal field directions below Tχmax 0.32 K, at which the temperature dependence of ac-susceptibility shows a local broad maximum. Two crossover lines were found below and above Hm. At high magnetic fields, the heavy-fermion state was rapidly suppressed with increasing magnetic field, and the field-induced ordered phase appeared in a very limited field direction around H || 111 above the transition field HQ= 60 kOe in the temperature range below TQ = 0.6 K. © Published under licence by IOP Publishing Ltd.

    DOI: 10.1088/1742-6596/391/1/012072

    Scopus

    researchmap

  • Field-induced quadrupolar ordered phase for H ∥ 〈111〉 in heavy-fermion compound YbCo<inf>2</inf>Zn<inf>20</inf> 査読

    Tetsuya Takeuchi, Shingo Yoshiuchi, Masahiro Ohya, Yuki Taga, Yusuke Hirose, Kiyohiro Sugiyama, Fuminori Honda, Masayuki Hagiwara, Koichi Kindo, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   80 ( 11 )   2011年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    Magnetic susceptibility, high-field magnetization up to 500 kOe, and specific heat in a wide temperature range from 0.06 to 300K were measured for single crystals of the cubic heavy-fermion compound YbCo2Zn 20 in order to elucidate the electronic states of the compound at low temperatures. A strong increase in the magnetic specific heat in the form of Cmag=T below ∼1K is approximately explained by the resonant level model for S = 1=2 with the Kondo temperature TK = 1 K, and an extremely large Cmag=T ≃ 8 J/(K2·mol) below about 0.2K is explained by considering the magnetic entropy of the doublet ground state in the 4f crystalline electric field (CEF) scheme of an Yb 3+ ion, which corresponds to an extremely large electronic specific heat coefficient. The field-induced ordered phase for H k h111i, which has recently been found by low-temperature magnetization measurements, was precisely studied by electrical resistivity and specific heat measurements, and was observed in a limited angular range around the h111i direction. On the basis of CEF analyses, the level crossing of the two lowest CEF states is essentially important to understand the field-induced ordered phase, which can be reduced to a field-induced antiferro-quadrupolar ordering based on the Γ3-type quadrupole moment O20 © 2011 The Physical Society of Japan.

    DOI: 10.1143/JPSJ.80.114703

    Web of Science

    Scopus

    researchmap

  • Fermi surface property and characteristic crystalline electric field effect in PrIr<inf>2</inf>Zn<inf>20</inf> 査読

    Masaki Matsushita, Jyunya Sakaguchi, Yuki Taga, Masahiro Ohya, Shingo Yoshiuchi, Hisashi Ota, Yusuke Hirose, Kentaro Enoki, Fuminori Honda, Kiyohiro Sugiyama, Masayuki Hagiwara, Koichi Kindo, Toshiki Tanaka, Yasunori Kubo, Tetsuya Takeuchi, Rikio Settai, Yoshichika Önuki

    Journal of the Physical Society of Japan   80 ( 7 )   2011年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    We measured the de Haas-van Alphen (dHvA) oscillations, electrical resistivity, magnetic susceptibility, magnetization, and specific heat of PrIr2Zn20, which has recently been suggested as a heavy-fermion superconductor. Several dHvA branches with small frequencies ranging from 0.33 × 106 to 8.00 × 106 Oe were detected in the dHvA experiment, which were well explained by the results of energy band calculations for LaIr2Zn20 using the lattice parameter of PrIr2Zn20. Moreover, the cyclotron effective mass is small, i.e., less than 1m0 (m0. rest mass of an electron). This means that 4f electrons are fully localized and do not contribute to the Fermi surface. Similar dHvA results were obtained for the reference compound LuIr2Zn20. Thus, superconductivity in PrIr2Zn20, which has been observed very recently below 0.05 K, is not due to heavy quasiparticles. In fact, the present superconductivity disappears at a magnetic field of 20 Oe. From the experimental results of magnetic susceptibility, magnetization, and specific heat, we estimated the 4f crystalline electric field (CEF) scheme of PrIr2Zn20: Γ3 (0 K)-Γ4 (separated from a non-Kramers Γ3 doublet by 36.0 K)-Γ1 (86.4 K)-Γ5 (103 K). On the basis of this CEF scheme, we discuss a broad Schottky peak in the magnetic specific heat at 0.4K and the metamagnetic-like anomaly of magnetization at Hm = 50 kOe for H || h100i. © 2011 The Physical Society of Japan.

    DOI: 10.1143/JPSJ.80.074605

    Web of Science

    Scopus

    researchmap

  • Electrical resistivity of Ce<inf>2</inf>Ir<inf>3</inf>Ge<inf>5</inf> under high pressure 査読

    M. Nakashima, T. Kawata, Y. Amako, S. Yoshiuchi, Y. Hirose, K. Matsubayashi, Y. Uwatoko, A. Thamizhavel, F. Honda, R. Settai, Y. Onuki

    Journal of the Physical Society of Japan   80 ( SUPPL. A )   895 - 897   2011年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    We measured electrical resistivity on antiferromagnet Ce2Ir 3Ge5 under high pressure up to 8 GPa. It is shown that the Néel temperature (= 9.5 K) at ambient pressure decreased by increased pressure. The Néel temperature seems to be zero at a critical pressure Pc ≃ 2.0 GPa suddenly. The variation by higher pressure above 2.0 GPa does not seem prominence up to 8 GPa. © 2011 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.80SA.SA066

    Scopus

    researchmap

  • Characteristic heavy fermion properties in YbCu<inf>2</inf>Si<inf>2</inf> and YbT<inf>2</inf>Zn<inf>20</inf> (T: Co, Rh, Ir) 査読

    Yoshichika Onuki, Shinichi Yasui, Masaki Matsushita, Shingo Yoshiuchi, Masahiro Ohya, Yusuke Hirose, Nguyen D. Dung, Fuminori Honda, Tetsuya Takeuchi, Rikio Settai, Kiyohiro Sugiyama, Etsuji Yamamoto, Tatsuma D. Matsuda, Yoshinori Haga, Toshiki Tanaka, Yasunori Kubo, Hisatomo Harima

    Journal of the Physical Society of Japan   80 ( SUPPL. A )   2011年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:PHYSICAL SOC JAPAN  

    We studied the Fermi surface properties of YbCu2Si2 and YbCu2Ge2 with the tetragonal structure by measuring the de Haas-van Alphen (dHvA) oscillations, together with the energy band calculations. It was clarified that 4f electrons contribute to the Fermi surface of a valence fluctuating compound YbCu2Si2, but not to that of a divalent compound YbCu2Ge2. Namely, the Fermi surface of YbCu2Si2 contains the 4f-components considerably and the corresponding cyclotron effective mass m *c of the main Fermi surface is large, m *c = 30-40m0 (m0: rest mass of an electron). We also studied the heavy fermion properties of YbT 2Zn20 (T: Co, Rh, Ir) with the cubic caged structure. The metamagnetic behavior or an abrupt nonlinear increase of magnetization was observed at 6 kOe in YbCo2Zn20, 63 kOe in YbRh 2Zn20, and 97 kOe in YbIr2Zn20 for H ∥ «100», which was measured at 60 mK in YbCo2Zn 20 and 1.3 K in YbRh2Zn20 and YbIr 2Zn20. The metamagnetic field is found to be a good parameter to reach the quantum critical point under pressure for YbIr 2Zn20. By measuring the electrical resistivity under pressure and magnetic field, we clarified that the electronic state close to the quantum critical point is realized in YbIr2Zn20 at 5.2 GPa and also YbCo2Zn20 at ambient pressure. The corresponding heavy cyclotron effective mass of 100-500m0 at 0 kOe was estimated from the field dependence of the √A value in the low-temperature electrical resistivity ρ=ρ0 + AT2 under pressure and magnetic field and the cyclotron mass obtained from the dHvA experiment at ambient pressure and high magnetic fields. © 2011 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.80SA.SA003

    Web of Science

    Scopus

    researchmap

  • Characteristic Heavy Fermion Properties in YbCu2Si2 and YbT2Zn20 (T: Co, Rh, Ir) 査読

    Yoshichika Onuki, Shinichi Yasui, Masaki Matsushita, Shingo Yoshiuchi, Masahiro Ohya, Yusuke Hirose, Nguyen D. Dung, Fuminori Honda, Tetsuya Takeuchi, Rikio Settai, Kiyohiro Sugiyama, Etsuji Yamamoto, Tatsuma D. Matsuda, Yoshinori Haga, Toshiki Tanaka, Yasunori Kubo, Hisatomo Harima

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   80   2011年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    We studied the Fermi surface properties of YbCu2Si2 and YbCu2Ge2 with the tetragonal structure by measuring the de Haas-van Alphen (dHvA) oscillations, together with the energy band calculations. It was clarified that 4f electrons contribute to the Fermi surface of a valence fluctuating compound YbCu2Si2, but not to that of a divalent compound YbCu2Ge2. Namely, the Fermi surface of YbCu2Si2 contains the 4f-components considerably and the corresponding cyclotron effective mass m(c)* of the main Fermi surface is large, m(c)*=30-40m(0) (m(0) : rest mass of an electron). We also studied the heavy fermion properties of YbT2Zn20 (T : Co, Rh, Ir) with the cubic caged structure. The metamagnetic behavior or an abrupt nonlinear increase of magnetization was observed at 6 kOe in YbCo2Zn20, 63 kOe in YbRh2Zn20, and 97 kOe in YbIr2Zn20 for H parallel to &lt; 100 &gt;, which was measured at 60 mK in YbCo2Zn20 and 1.3 K in YbRh2Zn20 and YbIr2Zn20. The metamagnetic field is found to be a good parameter to reach the quantum critical point under pressure for YbIr2Zn20. By measuring the electrical resistivity under pressure and magnetic field, we clarified that the electronic state close to the quantum critical point is realized in YbIr2Zn20 at 5.2 GPa and also YbCo2Zn20 at ambient pressure. The corresponding heavy cyclotron effective mass of 100-500m(0) at 0 kOe was estimated from the field dependence of the root A value in the low-temperature electrical resistivity rho = rho(0) + AT(2) under pressure and magnetic field and the cyclotron mass obtained from the dHvA experiment at ambient pressure and high magnetic fields.

    DOI: 10.1143/JPSJS.80SA.SA003

    Web of Science

    researchmap

  • Metamagnetic behaviour in CeCu<inf>6</inf> 査読

    Yusuke Hirose, Fuminori Honda, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   80 ( SUPPL. A )   2011年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:PHYSICAL SOC JAPAN  

    The metamagnetic behaviour, which corresponds to one of the characteristic properties in the heavy fermion compounds, was studied by measuring the electrical resistivity under pressure and magnetic field for a typical heavy fermion compound CeCu6 with orthorhombic structure. The transverse magnetoresistance at 100 mK indicated a peak structure at Hm = 20 kOe for the magnetic field H//c-axis under ambient pressure. Hm is found to increase linearly as a function of pressure and indicates Hm = 102 kOe at 1.75 GPa, for example. The quantum critical point is thus likely to exist at a slightly negative pressure value of ∼ 0.21 GPa from extrapolating Hm to zero. The ρ0 and A values in the electrical resistivity ρ = ρ0+AT2 decrease steeply in magnitude with increasing pressure and magnetic field, indicating that the heavy fermion state is destroyed by pressure and magnetic field. © 2011 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.80SA.SA065

    Web of Science

    Scopus

    researchmap

  • Magnetic-field-induced metallic state in β-US<inf>2</inf> 査読

    Kiyohiro Sugiyama, Yusuke Hirose, Kentaro Enoki, Shugo Ikeda, Etsuji Yamamoto, Naoyuki Tateiwa, Yoshinori Haga, Takanori Kida, Masayuki Hagiwara, Koichi Kindo, Fuminori Honda, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   80 ( SUPPL. A )   2011年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:PHYSICAL SOC JAPAN  

    β-US2 with the orthorhombic structure is an interesting compound of which the electrical property is changed from a metallic state to an insulating state at temperatures lower than 80 K. To clarify the present metal-insulator change, we carried out the magnetization and magnetoresistance measurements in magnetic fields up to 50 T. The magentization at 4.2 K saturates above 40 T, reaching 1.75 μB/U at 50 T for the magnetic field along the magentic easy-axis, namely the [001] direction. The corresponding electrical resistivity at 4.2 K is steeply reduced in magnitude from 1 × 103 Ω·cm to 2 × 10-2 Ω·cm at 50 T only when the magnetic field is applied along the [001] direction. The temperature dependence of the electrical resistivity at 50 T indicates a usual metallic behaviour. The conduction electrons are most likely released from the trapped U-sites when the 5f-CEF magnetic moments are fully polarized in high magnetic field of 50 T. The present experimental results are discussed from the viewpoint of the magnetic polaron. © 2011 The Physical Society of Japan.

    DOI: 10.1143/JPSJS.80SA.SA104

    Web of Science

    Scopus

    researchmap

  • Magnetic and superconducting properties of CeRhGe<inf>2</inf> and CePtSi<inf>2</inf> 査読

    Yusuke Hirose, Naoto Nishimura, Fuminori Honda, Kiyohiro Sugiyama, Masayuki Hagiwara, Koichi Kindo, Tetsuya Takeuchi, Etsuji Yamamoto, Yoshinori Haga, Masato Matsuura, Kazuma Hirota, Akira Yasui, Hiroshi Yamagami, Rikio Settai, Yoshichika Onuki

    Journal of the Physical Society of Japan   80 ( 2 )   2011年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    We synthesized a new compound of CeRhGe2 with the orthorhombic CeNiSi2-type structure. By measuring the electrical resistivity, magnetic susceptibility, magnetization, specific heat, and neutron scattering for single crystals, CeRhGe2 was found to order antiferromagnetically below TN = 7.6 K with an ordered moment of 1.3 μB/Ce oriented along the magnetic easy-axis of the c-axis. Similar measurements were also carried out for CePtSi2 single crystals. From the experimental results of anisotropic magnetic susceptibility and magnetization, the crystalline electric field (CEF) scheme was obtained for CeRhGe2 and CePtSi2, together with the similar compound CeNiGe2. Furthermore, we carried out pressure experiments by measuring the electrical resistivity of CePtSi2 and CeRhGe2. In the quantum critical region where the Néel temperature becomes zero, we observed superconductivity in CePtSi2 and most likely CeRhGe2, at 1.5 and 7.1 GPa, respectively. The upper critical field of CePtSi2 was found to be highly anisotropic with respect to the three principal field directions. © 2011 The Physical Society of Japan.

    DOI: 10.1143/JPSJ.80.024711

    Web of Science

    Scopus

    researchmap

  • Relation between metamagnetic transition and quantum critical point in heavy fermion compound YbIr<inf>2</inf>Zn<inf>20</inf> 査読

    Y. Onuki, S. Yasui, S. Yoshiuchi, M. Ohya, M. Matsushita, Y. Hirose, T. Takeuchi, F. Honda, R. Settai, K. Sugiyama, E. Yamamoto, Y. Haga

    Journal of Physics: Conference Series   273 ( 1 )   2011年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We measured the electrical resistivity in magnetic field H under pressure P for a heavy fermion compound YbIr2Zn20. The quantum critical point is found to be defined as an electronic state where the metamagnetic transition field Hm becomes zero. This is realized at Pc ≃ 5.2 GPa. The most characteristic feature in the quantum critical pressure region is an anomalously large A value of the electrical resistivity ρ = ρ0 + AT2, reaching A 380μΩcm/K 2 at 5.0 GPa, which is, however, strongly reduced with increasing the magnetic field: A 1.45μΩcm/K2 at 80 kOe. From the result of the de Haas-van Alphen experiment at ambient pressure, the corresponding cyclotron effective mass of conduction electrons at 5.0 GPa is 400 - 500 m 0 (m0: rest mass of an electron). © Published under licence by IOP Publishing Ltd.

    DOI: 10.1088/1742-6596/273/1/012013

    Scopus

    researchmap

  • Metamagnetic transition in heavy fermion compounds YbT<inf>2</inf>Zn <inf>20</inf> (T : Co, Rh, Ir) 査読

    Yusuke Hirose, Masatoshi Toda, Shingo Yoshiuchi, Shinichi Yasui, Kiyohiro Sugiyama, Fuminori Honda, Masayuki Hagiwara, Koichi Kindo, Rikio Settai, Yoshichika Onuki

    Journal of Physics: Conference Series   273 ( 1 )   2011年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We measured the magnetization in high magnetic fields up to 500kOe, together with the magnetic susceptibility, ac-susceptibility and magnetoresistance for heavy fermion compounds YbT2Zn20 (T : Co, Rh, Ir). The metamagnetic behaviour or an abrupt nonlinear increase of magnetization was observed at the magnetic field Hm at temperatures lower than a characteristic temperature Tχmax below which the magnetic susceptibility becomes almost constant : Tχmax = 7.4K and Hm = 97kOe in YbIr2Zn20, T χmax = 5.3K and Hm = 64kOe in YbRh2Zn 20, and Tχmax = 0.32K and Hm = 6kOe in YbCo2Zn20. From the present data and the data in several Ce and U heavy fermion compounds, a simple relation between Tχmax and Hm was obtained : Hm(kOe) = 15Tχmax(K) . © Published under licence by IOP Publishing Ltd.

    DOI: 10.1088/1742-6596/273/1/012003

    Web of Science

    Scopus

    researchmap

  • Pressure-induced superconductivity in non-centrosymmetric compound CeIrGe<inf>3</inf> 査読

    Fuminori Honda, Ismardo Bonalde, Shingo Yoshiuchi, Yusuke Hirose, Taichi Nakamura, Katsuya Shimizu, Rikio Settai, Yoshichika Nuki

    Physica C: Superconductivity and its Applications   470 ( SUPPL.1 )   S543 - S544   2010年12月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    We have carried out electrical resistivity experiments on the non-centrosymmetric compound CeIrGe3 under high pressures up to 24 GPa. CeIrGe3 is an antiferromagnet with the Néel temperature TN1=8.5K and a successive magnetic transition at TN2=4.7K at ambient pressure. With increasing pressure, TN1 and TN2 merge around 3 GPa, becomes unchanged up to 10 GPa, and indicates a step-like decrease up to 20 GPa. Further increasing pressure, we have found superconductivity above 20 GPa with a transition temperature of 1.6 K at 24 GPa. The upper critical field for the magnetic field along the tetragonal [0 0 1] direction is expected to be much larger than 15 T. © 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.physc.2009.10.126

    Web of Science

    Scopus

    researchmap

  • Metamagnetic Behavior in Heavy-Fermion Compound YbIr2Zn20 査読

    Tetsuya Takeuchi, Shinichi Yasui, Masatoshi Toda, Masaki Matsushita, Shingo Yoshiuchi, Masahiro Ohya, Keisuke Katayama, Yusuke Hirose, Naohisa Yoshitani, Fuminori Honda, Kiyohiro Sugiyama, Masayuki Hagiwara, Koichi Kindo, Etsuji Yamamoto, Yoshinori Haga, Toshiki Tanaka, Yasunori Kubo, Rikio Settai, Yoshichika Onuki

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   79 ( 6 )   2010年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    The metamagnetic behavior in the heavy-fermion compound YbIr2Zn20 with a cubic structure was studied by magnetization, de Haas-van Alphen (dHvA) oscillation, magnetoresistance, specific heat, thermal expansion, and magnetostriction measurements in single-crystalline samples. A metamagnetic anomaly at H-m similar or equal to 100 kOe was found to exist in all field directions in the cubic crystal structure. The cyclotron effective mass m(c)*, the coefficient A in the Fermi liquid relation of electrical resistivity rho = rho(0) + AT(2), and the electronic specific heat coefficient C/T indicate a peak at the metamagnetic field H-m. The negative thermal expansion and negative volume magnetostriction suggest that the valence of the Yb ion gradually changes from a 4f-itinerant state to a trivalent state with increasing magnetic field, and an almost trivalent state is realized above the metamagnetic field H-m. On the other hand, the topology of the Fermi surface is approximately unchanged below and above H-m in the dHvA experiment.

    DOI: 10.1143/JPSJ.79.064609

    Web of Science

    researchmap

  • Pressure-induced superconductivity and large upper critical field in the noncentrosymmetric antiferromagnet CeIrGe<inf>3</inf> 査読

    F. Honda, I. Bonalde, K. Shimizu, S. Yoshiuchi, Y. Hirose, T. Nakamura, R. Settai, Y. Onuki

    Physical Review B - Condensed Matter and Materials Physics   81 ( 14 )   2010年4月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    We report on the discovery of superconductivity in the noncentrosymmetric antiferromagnet CeIrGe3 below 1.5 K at a pressure of 20 GPa. We performed electrical resistivity measurements in single crystals of CeIrGe 3 in the temperature range 0.04-300 K at pressures up to 24 GPa. From these measurements we deduced the P-T phase diagram. The data imply a crossover from localized to itinerant 4f electrons of the type caused by a Kondo-lattice phenomenon as pressure increases. The antiferromagnetic phase weakens with pressure and eventually vanishes above 22 GPa, indicative of the occurrence of a quantum critical point. Superconductivity appears inside the antiferromagnetic phase near this critical point. After the disappearance of the magnetic ordering a non-Fermi-liquid behavior is observed. Resistivity measurements taken at 24 GPa in magnetic fields up to 8 T strongly suggest that CeIrGe3 has a very large upper critical field for H ∥ [001]. © 2010 The American Physical Society.

    DOI: 10.1103/PhysRevB.81.140507

    Scopus

    researchmap

  • Pressure-induced superconductivity in CePd<inf>5</inf>Al<inf>2</inf> and CeRhGe<inf>2</inf>, new family of heavy fermion superconductors 査読

    Fuminori Honda, Shingo Yoshiuchi, Yusuke Hirose, Taichi Nakamura, Etsuji Yamamoto, Naoyuki Tateiwa, Yoshinori Haga, Tetsuya Takeuchi, Rikio Settai, Yoshichika Onuki

    Physica Status Solidi (B) Basic Research   247 ( 3 )   617 - 620   2010年3月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    Antiferromagnets CePd5Al2 and CeRhGe2 with the quasi-two dimensional electronic state have been found to become superconductive by measuring the electrical resistivity under pressure. In these compounds, the Néel temperature decreases at high pressure and becomes approximately zero at critical pressure Pc = 9 GPa in CePd5Al2 and Pc = 7 GPa in CeRhGe2. Superconductivity was observed around Pc. In CePd5Al2, the upper critical field Hc2 is found to be highly anisotropic among H||[001] and [100], reflecting nearly cylindrical Fermi surfaces along the tetragonal [001] direction. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

    DOI: 10.1002/pssb.200983055

    Web of Science

    Scopus

    researchmap

  • Heavy Fermion State in YbIr2Zn20 査読

    Shingo Yoshiuchi, Masatoshi Toda, Masaki Matsushita, Shinichi Yasui, Yusuke Hirose, Masahiro Ohya, Keisuke Katayama, Fuminori Honda, Kiyohiro Sugiyama, Masayuki Hagiwara, Koichi Kindo, Tetsuya Takeuchi, Etsuji Yamamoto, Yoshinori Haga, Rikio Settai, Toshiki Tanaka, Yasunori Kubo, Yoshichika Onuki

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   78 ( 12 )   2009年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PHYSICAL SOC JAPAN  

    We measured the high-field magnetization and de Haas-van Alphen (dHvA) oscillations for YbIr2Zn20 with a cubic crystal structure, together with the electrical resistivity and magnetic susceptibility. The magnetic Susceptibility chi with an effective magnetic moment of Yb3+ becomes temperature-independent at low temperatures, with a broad peak at T-chi max = 7.4 K for H parallel to &lt; 110 &gt;. The corresponding magnetization indicates a metamagnetic transition at H-m = 120kOe, consistent with a T-chi max vs H-m relation in the Ce- and U-based heavy fermion Compounds. The large cyclotron masses of 4-27 m(0) are detected in the dHvA experiment, and are found to be reduced at magnetic fields higher than H-m = 120 kOe. The resistivity follows the Fermi liquid relation rho = rho(0) +AT(2) under magnetic field, and the root A value is also found to have a maximum at H-m as a function of magnetic field. From the present experimental results, together with the results of 4f-itinerant energy band calculations, the 4f electrons are found to contribute to the heavy fermion state in YbIr2Zn20.

    DOI: 10.1143/JPSJ.78.123711

    Web of Science

    researchmap

▶ 全件表示

MISC

▶ 全件表示

講演・口頭発表等

▶ 全件表示

共同研究・競争的資金等の研究

  • 励起子絶縁体における不純物効果の研究

    研究課題/領域番号:20K14414  2020年4月 - 2023年3月

    日本学術振興会  科学研究費助成事業 若手研究  若手研究

    広瀬 雄介

      詳細を見る

    配分額:4160000円 ( 直接経費:3200000円 、 間接経費:960000円 )

    researchmap

  • 超強磁場・極低温・高圧下での電気的・磁気的測定のための非金属製圧力セルの開発

    研究課題/領域番号:25610090  2013年4月 - 2015年3月

    日本学術振興会  科学研究費助成事業 挑戦的萌芽研究  挑戦的萌芽研究

    摂待 力生, 広瀬 雄介

      詳細を見る

    配分額:3900000円 ( 直接経費:3000000円 、 間接経費:900000円 )

    一般に重い電子系の磁気秩序温度は数K,超伝導転移温度は1K程度と低いのに対し,磁気的な性質が変化する磁場は数~数十Tと高い。このような系の研究にはパルス強磁場を用いた数十Tの磁場が必要となる。パルス強磁場で大きな問題となるのは,渦電流による発熱である。これが重い電子系の強磁場・極低温・高圧実験を困難なものとしている。そこで,本研究では,1K以下の極低温・40Tを超えるパルス強磁場下で数GPaの圧力を発生できる圧力セルの開発を目指した。その結果,1.5K,60Tで4GPaの圧力を発生できる圧力セルの開発に成功するとともに,CeRh2Si2における4f電子の局在的性質と遍歴的性質の分離に成功した。

    researchmap

  • 希土類化合物の量子臨界点近傍における量子状態の研究

    研究課題/領域番号:11J56433  2011年 - 2012年

    日本学術振興会  科学研究費助成事業 特別研究員奨励費  特別研究員奨励費

    廣瀬 雄介

      詳細を見る

    配分額:600000円 ( 直接経費:600000円 )

    物質探索・超伝導・メタ磁性を切り口として量子臨界点近傍における物理現象の研究を行なってきた。以下、その成果をそれぞれ示す。
    ○物質探索
    Ce化合物に対してYb化合物では4f電子を媒介とした超伝導の例がほとんどない。NIMSのデータベースによると、YbとGaの二元系の物質で超伝導を示す物質があるのだが、明示する論文はない。そこで、Yb-Gaの二元系の物質であるYbGa_6,YbGa_5,YbGa_4の単結晶育成に取り組んだ。その中でYbGa_4の単結晶育成に初めて成功した。この物質ではf電子が伝導に関与せずYbイオンは二価の状態であることがわかった。
    ○超伝導
    結晶構造に反転中心がない系ではスピン一重項と三重項が混ざった超伝導が発現すると理論的に言われている。Ce系ではCeIrSi_3など空間反転対称性のないことを反映した超伝導が示唆されているがLa化合物では少ない。超伝導体LaNic2が候補の一つであり、過去の研究では三重項状態と通常のBCS超伝導のどちらの主張も存在する。過去の実験は全て多結晶体を用いて行われていたものであり、単結晶を育成し超伝導とフェルミ面に関して研究を行なった。比熱測定より、BCS型の超伝導体であるとわかった。また純良な結晶であったのでdHvA振動が得られ、反対称性スピン軌道相互作用で分裂したフェルミ面を観測した。
    ○メタ磁性
    重い電子系化合物YbT_2Zn_<20>(T:Co,Rh,Ir)やUT_2Zn_,20>(T:Co,Ir)において磁化率に極大をもつ温度以下で重い電子系特有のメタ磁性を転移磁場Hmで観測してきた。UIr_2Zn_<20>においてホール抵抗の磁場依存性を調べるとHmで急激に変化しており、メタ磁性に伴う電子状態の大きな変化を示唆する興味深い結果を得た。

    researchmap

 

担当経験のある授業科目(researchmap)

  • 物性物理学

    機関名:新潟大学

     詳細を見る

  • 物理学実験

    機関名:新潟大学

     詳細を見る

担当経験のある授業科目

  • 物理学基礎実習b

    2022年
    -
    現在
    機関名:新潟大学

  • 理学基礎演習

    2022年
    -
    現在
    機関名:新潟大学

  • Physics TodayII

    2022年
    -
    現在
    機関名:新潟大学

  • 物理学実験C

    2021年
    -
    現在
    機関名:新潟大学

  • 物理学実験D

    2021年
    -
    現在
    機関名:新潟大学

  • 物理学基礎実習a

    2021年
    -
    現在
    機関名:新潟大学

  • 現代物理学セミナーB

    2021年
    -
    現在
    機関名:新潟大学

  • 自然科学基礎実験

    2021年
    -
    現在
    機関名:新潟大学

  • 現代物理学セミナーA

    2021年
    -
    現在
    機関名:新潟大学

  • 物理学特論IV

    2021年
    機関名:新潟大学

  • 理学スタディ・スキルズ

    2021年
    機関名:新潟大学

  • 物理学実験B

    2020年
    -
    現在
    機関名:新潟大学

  • 物理学実験A

    2020年
    -
    現在
    機関名:新潟大学

  • 物性物理学

    2020年
    -
    現在
    機関名:新潟大学

  • 専門力アクティブ・ラーニング

    2018年
    -
    2021年
    機関名:新潟大学

  • 理学スタディ・スキルズ

    2017年
    -
    2021年
    機関名:新潟大学

  • 自然科学基礎実験

    2017年
    -
    2018年
    機関名:新潟大学

  • 物性物理学I

    2017年
    機関名:新潟大学

  • 初等物理学実験

    2015年
    -
    2016年
    機関名:新潟大学

  • 物性物理学II

    2015年
    -
    2016年
    機関名:新潟大学

  • 現代物理学への招待(物理学学習法)

    2015年
    -
    2016年
    機関名:新潟大学

  • 物理学基礎実験

    2014年
    -
    2016年
    機関名:新潟大学

  • 物理学実験a

    2013年
    機関名:新潟大学

  • 物理学実験b

    2013年
    機関名:新潟大学

▶ 全件表示