研究者詳細 - 摂待　力生

MISC - 摂待　力生

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25aYA-4 PrOs_4P_<12>のdHvA効果(25aYA スクッテルダイト(Pr系),領域8(強相関係:高温超伝導,強相関f電子系など))

菅原仁, 菊地大輔, 佐藤英行, 遠藤豊明, 摂待力生, 大貫惇睦

日本物理学会講演概要集 61 ( 2 ) 483 - 483 2006年8月

23aYA-4 CePt_3Siにおける磁性と超伝導の比熱による研究II(23aYA 重い電子系超伝導(CePt_3Si等),領域8(強相関系:高温超伝導,強相関f電子系など))

竹内徹也, 辻野真彦, 摂待力生, 大貫惇睦

日本物理学会講演概要集 61 ( 2 ) 379 - 379 2006年8月

24aYA-4 CeRhIn_5における磁気臨界点近傍の磁性と超伝導:^<115>In-NQRによる研究(24aYA 重い電子系超伝導(Ce115等),領域8(強相関系:高温超伝導,強相関f電子系など))

八島光晴, 川崎慎司, 椋田秀和, 北岡良雄, 宍戸寛明, 摂待力生, 大貫惇睦

日本物理学会講演概要集 61 ( 2 ) 432 - 432 2006年8月

Double superconducting transition of CePt<inf>3</inf>Si probed by susceptibility measurements

Keisuke Nakatsuji, Akihiko Sumiyama, Yasukage Oda, Takashi Yasuda, Rikio Settai, Yoshichika Onuki

Journal of the Physical Society of Japan 75 ( 8 ) 084717 - 084717-5 2006年8月

記述言語：英語出版者・発行元：一般社団法人日本物理学会

We have investigated ac and dc magnetic susceptibilities (χacand χdc) of the heavy-fermion superconductor CePt3Si (Tc+∼ 0.75 K) for two single crystals that show a specific heat anomaly at Tc-∼ 0.4 K. One crystal shows a double transition at Tc+and Tc-in the form of structures in the out-of-phase component of χacand in χdcmeasured in the cooling process. The magnetic field dependence of χacsuggests that the lower transition also originates in superconductivity. In contrast, only the higher transition has been detected in susceptibility measurements of the other crystal whose specific heat has a less dominant peak near Tc-and a broad peak at Tc+. These results suggest that CePt3Si consists of two superconducting phases with different Tc's, whose volume fraction varies from sample to sample. ©2006 The Physical Society of Japan.

DOI： 10.1143/JPSJ.75.084717

Magnetic and Fermi surface properties in NpIn3

Dai Aoki, Yoshiya Homma, Hironori Sakai, Shugo Ikeda, Yoshinobu Shiokawa, Etsuji Yamamoto, Akio Nakamura, Yoshinori Haga, Rikio Settai, Yoshichika Onuki

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 75 ( 8 ) 2006年8月

記述言語：英語出版者・発行元：PHYSICAL SOC JAPAN

We succeeded in growing a high-quality single crystal of NpIn3 by the In-flux method, and measured the electrical resistivity, specific heat, magnetic susceptibility, magnetization and de Haas-van Alphen (dHvA) effect. Ferromagnetic and antiferromagnetic orderings occur at T-C = 14K and T-N = 10K, respectively, together with another transition at T* = 8K. When the magnetic field is applied to the sample, the antiferromagnetic state is finally changed into a ferromagnetic state with two metamagnetic transitions. The antiferromagnetic ordering and two metamagnetic transitions are found to be of the first-order phase transition. In the dHvA experiments, we observed three dHvA branches with the cyclotron mass ranging from 3.4 to 14m(0). These dHvA branches are discussed from a viewpoint of the 5f-localized model based on the Fermi surface of LaIn3.

DOI： 10.1143/JPSJ.75.084710

Unique magnetic properties of NdRhIn5, TbRhIn5, DyRhIn5, and HoRhIn5

Nguyen Van Hieu, Hiroaki Shishido, Tetsuya Takeuchi, Arumugam Thamizhavel, Hiroshi Nakashima, Kiyohiro Sugiyama, Rikio Settai, Tatsuma D. Matsuda, Yoshinori Haga, Masayuki Hagiwara, Koichi Kindo, Yoshichika Onuki

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 75 ( 7 ) 2006年7月

記述言語：英語出版者・発行元：PHYSICAL SOC JAPAN

We grew single crystals of NdRhIn5, TbRhIn5, DyRhIn5, and HoRhIn5 with the tetragonal crystal structure and measured the magnetic susceptibility and magnetization. NdRhIn5 is an antiferromagnet with a Neel temperature T-N = 11.6 K. Below T-N, magnetization reveals two metamagnetic transitions at H-ml = 70 kOe and H-m2 = 93 kOe for the magnetic field along the [001] direction. The saturation moment of 2.5 mu(B)/Nd is in good agreement with the staggered Nd moment determined by the neutron diffraction experiment. These metamagnetic transitions correspond to the change of the magnetic structure. TbRhIn5, DyRhIn5 and HoRhIn5 are found to be antiferromagnets with T-N = 47.3, 28.1, and 15.8 K, respectively. The magnetization curves of these compounds are also quite similar to those of NdRhIn5, revealing two metamagnetic transitions. The magnetic structures in magnetic fields are proposed by considering the exchange interactions based on the crystal structure.

DOI： 10.1143/JPSJ.75.074708

Magnetic and fermi surface properties in ferromagnets NdRh3B2 and GdRh3B2

Yoshiko Obiraki, Hiroshi Nakashima, Andrei Galatanu, Tatsuma D. Matsuda, Yoshinori Haga, Tetsuya Takeuchi, Kiyohiro Sugiyama, Koichi Kindo, Masayuki Hagiwara, Rikio Settai, Hisatomo Harima, Yoshichika Onuki

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 75 ( 6 ) 2006年6月

記述言語：英語出版者・発行元：PHYSICAL SOC JAPAN

We succeeded in growing single crystals of ferromagnets NdRh3B2 and GdRh3B2 with the hexagonal structure, and measured the electrical resistivity, specific heat, magnetic susceptibility and magnetization. From these measurements, the Curie temperature T-C is determined as T-C = 10.2K in NdRh3B2 and T-C = 93 K in GdRh3B2. The magnetic moments of about 2.5 mu(B) in NdRh3B2 and 7.7 mu(B) in GdRh3B2 are oriented in the basal plane. The crystalline electric field scheme is proposed for NdRh3B2 on the basis of the experimental results of Schottky anomaly in the specific heat and anisotropic susceptibility and magnetization. The Fermi surface in NdRh3B2 is very similar to that in a non-4f reference compound LaRh3B2, possessing the quasi-one dimensional electronic character.

DOI： 10.1143/JPSJ.75.064702

A change of the Fermi surface in CeRhIn5 under pressure

H. Shishido, R. Settai, H. Harima, Y. Onuki

PHYSICA B-CONDENSED MATTER 378-80 92 - 93 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

We carried out the de Haas-van Alphen (dHvA) experiment for an antiferromagnet CeRhIn5 under high pressures up to 3 GPa. The main dHvA branches alpha(i) and beta(2) at ambient pressure, which are well explained by Fermi surfaces of LaRhIn5, are unchanged up to about 2.4 GPa. Above 2.4 GPa, new dHvA branches appear, which are in good agreement with the corresponding dHvA branches of a 4f-itinerant heavy fermion superconductor CeCoIn5. These results indicate that the 4f-electronic state is changed from localized to itinerant at a critical pressure Pc similar or equal to 2.4 GPa. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.037

Evidence for the first-order phase transition from antiferromagnetism to paramagnetism in CeRhIn5

M. Yashima, S. Kawasaki, Y. Kitaoka, H. Shishido, R. Settei, Y. Onuki

PHYSICA B-CONDENSED MATTER 378-80 94 - 95 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

The systematic and comprehensive NQR experiments near P-c are reported to address an intimate interplay between superconductivity (SC) and antiferromagnetism (AFM) of antiferromagnetic heavy-fermion compounds CeRhIn5 via the nuclear-quadrupole-resonance (NQR) measurements under pressure (P). The extensive measurements of In-NQR spectrum have revealed that a first-order transition occurs from the coexistent phase of AFM and SC to the single phase of SC at a critical pressure P-c approximate to 2GPa. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.537

Pressure-induced superconductivity in ferromagnet UIr without inversion symmetry

TC Kobayashi, S Fukushima, H Hidaka, H Kotegawa, T Akazawa, E Yamamoto, Y Haga, R Settai, Y Onuki

PHYSICA B-CONDENSED MATTER 378-80 355 - 358 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

High-pressure AC-susceptibility measurement has been carried out in UIr. Three series of peaks corresponding to the successive ferromagnetic transitions indicate the existence of three ferromagnetic phases FM 1-3. The phase boundary between FM2 and FM3 was not realized in the resistivity measurement. The Meissner effect is observed successfully in the pressure range of 2.63-2.74 GPa where the peak of AC-susceptibility survives. This result indicates that the superconducting phase is embedded in the FM3 phase with the ordered moment less than 0.051 mu(B)/U and adjoins the quantum critical point. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.26

Pressure-induced superconductivity of Ce2Ni3Ge5

M Nakashima, H Kohara, A Thamizhavel, TD Matsuda, Y Haga, M Hedo, Y Uwatoko, R Settai, Y Onuki

PHYSICA B-CONDENSED MATTER 378-80 402 - 403 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

The Neel temperature of Ce2Ni3Ge5 decreases with increasing pressure P and becomes zero at a critical pressure P-c similar or equal to 4GPa. The heavy fermion state was found to be formed around P,, in which pressure region superconductivity was found below 0.26 K. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.063

Pressure effect on magnetism and superconductivity in CePt3Si

T Takeuchi, M Shiimoto, H Kohara, T Yasuda, S Hashimoto, R Settai, Y Onuki

PHYSICA B-CONDENSED MATTER 378-80 376 - 378 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

Magnetism and superconductivity in the heavy-fermion superconductor CePt3Si have been studied under pressure. The antiferromagnetic and superconducting transition temperatures, T-N and T-sc, respectively, decrease by applying pressure. T-N becomes zero around 0.6-0.7 GPa, while the pressure dependence of T-sc exhibits a shoulder-like feature around 0.7 GPa, and superconductivity is found to persist in the pressure range up to about 1.5 GPa. A broad peak around 5 K in the temperature derivative of thermal expansion alpha(T) and electrical resistivity d rho(T)/dT at ambient pressure begins to shift to higher temperatures above 0.7 GPa. These results suggest that a critical pressure exists around 0.6-0.7 GPa in CePt3Si. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.132

Low-temperature thermal conductivity of noncentrosymmetric CePt3Si

K Izawa, Y Kasahara, Y Matsuda, K Behnia, T Yasuda, R Settai, Y Onuki

PHYSICA B-CONDENSED MATTER 378-80 361 - 362 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

We measured the thermal conductivity of recently discovered heavy fermion CePt3Si without inversion symmetry center down to 40 mK in order to clarify the superconducting gap structure. The results place an important constraint on the order parameter symmetry, that is CePt3Si is most likely to have line nodes. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.128

Novel superconductivity in CePt3Si: A Si-29-NMR study

M Yogi, Y Kitaoka, H Mukuda, S Hashimoto, T Yasuda, R Settai, TD Matsuda, Y Haga, Y Onuki, P Rogl, E Bauer

PHYSICA B-CONDENSED MATTER 378-80 359 - 360 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

We report a Knight-shift (K-29) study of Si-29 of the noncentrosymmetric heavy-fermion superconductor CePt3Si. The spin part of 29K is deduced to be K-s = 0.13-0.18% and 0.19-0.22% at respective fields of H = 2.0061 and 0.8671 T. The K-29(c) for the field direction H parallel to c-axis unchanges across T-c, suggesting that a two-component order parameter composed of spin-singlet and spin-triplet pairing components is realized. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.127

Change of the Fermi surface in CeIn3: From localized to itinerant

R. Settai, T. Kubo, T. D. Matsuda, Y. Haga, Y. Onuki, H. Harima

PHYSICA B-CONDENSED MATTER 378-80 417 - 418 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

We have studied a change of the Fermi surface in an antiferromagnet CeIn3 via the de Haas-van Alphen experiment for the magnetic field along H parallel to < 100 > and < 111 > under pressure at about 2.7 GPa. We have observed a large main spherical Fermi surface named a, which indicates that the electronic state of 4f electron in CeIn3 changes from localized to itinerant. The cyclotron effective mass m(c)* ofthis main Fermi surface is extremely enhanced: m(c)* 60m(0) at 2.75 GN for H parallel to < 100 >. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.146

The electronic state tuned by high pressure in a ferromagnet CePtAl

T Ueda, M Nakashima, H Nakashima, A Thamizhavel, M Hedo, Y Uwatoko, TD Matsuda, Y Haga, R Settai, Y Onuki

PHYSICA B-CONDENSED MATTER 378-80 801 - 802 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

CePtAl crystallizes in the TiNiSi-type orthorhombic crystal Structure. It orders ferromagnetically below a Curie temperature is T-C = 5.9 K. We have measured the electrical resistivity under high pressures. The Curie temperature found to increase slightly with increasing pressure, and the ferromagnetic ordering becomes obscure at 5.0 GPa. With further increasing pressure, the ferromagnetic state is changed into the non-magnetic state. The A and p(0) values in the resistivity of p = p(0) + AT(2) with a Fermi-liquid relation become maximum around 5-6 GPa. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.292

Anisotropic magnetic properties of Ce2Ni3Ge5 single crystal

A Thamizhavel, Sugitani, I, Y Obiraki, M Nakashima, Y Okuda, TD Matsuda, Y Haga, T Takeuchi, K Sugiyama, R Settai, Y Onuki

PHYSICA B-CONDENSED MATTER 378-80 841 - 842 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

We have succeeded in growing single crystals of Ce2Ni3Ge5, which crystallizes in the orthorhombic crystal structure, by the flux method and studied the anisotropic physical properties by measuring the electrical resistivity, magnetic susceptibility and specific heat. The results of these measurements indicate that Ce2Ni3Ge5 undergoes two antiferromagnetic transitions at T-N1 = 4.9 K and T-N2 = 4.3 K. The electrical resistivity and susceptibility measurements reveal strong anisotropic magnetic properties. From the specific heat measurement the electronic specific heat coefficient was found to be 90 mJ/K-2 Cc mol. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.483

Crossover of the 5f electrons from itinerant to localized in UPtGa5

Y Onuki, S Ikeda, H Yamagami, A Galatanu, Y Haga, TD Matsuda, E Yamamoto, R Settai

PHYSICA B-CONDENSED MATTER 378-80 972 - 973 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

UPtGa5 with the tetragonal structure is an antiferromagnet with a Neel temperature T-N = 26 K and a small ordered moment mu(s) = 0.341 mu(B)/U. From the de Haas-van Alphen experiment and the magnetic susceptibility measurement at high temperatures up to 800K, together with the spin (orbital)-polarized 5f-itinerant band calculations, the 5f electrons are found to be changed from the itinerant nature at low temperatures to the localized nature at high temperatures. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.372

Fermi surface properties in an enhanced Pauli paramagnet NpGe3

D Aoki, H Yamagami, Y Homma, Y Shiokawa, E Yamamoto, A Nakamura, Y Haga, R Settai, Y Onuki

PHYSICA B-CONDENSED MATTER 378-80 978 - 980 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

We grew high-quality single crystals of an enhanced Pauli paramagnet NpGe3 and measured the de Haas-van Alphen (dHvA) effect. The topology of the Fermi surfaces are well explained by the band calculations based on the 5f-itinerant band model. The cyclotron effective masses are ranging from 2.6 to 16m(0), which are approximately 3.5 times enhanced from the corresponding band masses. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.373

Single crystal growth and observation of the de Haas-van Alphen effect in ThIn3

TD Matsuda, Y Haga, H Shishido, S Ikeda, H Harima, R Settai, Y Onuki

PHYSICA B-CONDENSED MATTER 378-80 1021 - 1022 2006年5月

記述言語：英語出版者・発行元：ELSEVIER SCIENCE BV

We have succeeded in growing a high-quality single crystal of ThIn3 with the cubic structure by the In-flux method and measured the de Haas-van Alphen (dHvA) effect. Several dHvA branches were observed, ranging from 9.0 x 10(6) to 9.37 x 10(8) Oe. The experimental results are compared to the dHvA results of CeIn3 under pressure of 2.7 GPa. together with the results of energy band calculations. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.01.470

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