| Co-Investigator(Kenkyū-buntansha) |
SAKINE Chihiro Muroran Institute of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (60261385)
LEE Chul-ho AIST, Energy Electronics institute, Researcher, 電力エネルギー研究部門, 研究員 (80358358)
MATSUHIRA Kazuyuki Kyushu Institute of Technology, Faculty of Engineering, Research Associate, 工学部, 助手 (40312342)
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| Research Abstract |
Filled skutterudite compounds LnT_4X_<12> (Ln=Lanthanide ; T=Fe,Ru,Os ; X=P,As,Sb) with space group Im-3 (T^5_h, #204) have attracted much attention because of wide variety of physical properties at low temperature, such as metal-insulator transition, multipole order, heavy-fermion behavior, non Fermi liquid behavior and exotic superconductivity. This remarkable feature is caused by a strong p-f hybridization effect, a unique band structure and an orbital degree of freedam due to f electron in Ln site with cubic symmetry.
We have prepared many skutterudites with lighter lanthanide at high temperatures and high pressures. However, few filled skutterudites with heavy lanthanide have been synthesized. We have succeeded to prepare for the first time new filled skutterudites with heavy lanthanide, LnT_4P_<12> (Ln=heavy lanthanide, including Y ; T=Fe,Ru,Os) by the high-pressure technique. New filled skutterudites LnFe_4P_<12> (Ln=Tb,Dy,Ho,Er,Tm,Yb,Lu and Y) were prepared and studied. LnFe_4P_<12> (Ln=Gd,Tb,Dy,Ho,Er) are ferromagnets. YFe_4P_<12> and LuFe_4P_<12> are superconductors. Tm, Yb compounds are paramagnetic down to low temperature. For Ru system, LfRu_4P_<12> (Ln=Gd,Tb,Y) were prepared under high pressure. GdRu_4P_<12> and TbRu_4P_<12> are antiferromagnets. YRu_4P_<12> is a new superconductor (transition temperature Tc=9K). For Os system, new filled skutterudites LnOs_4P_<12> (Ln=Sm,Eu,Gd,Tb,Dy,Ho and Y) were prepared and studied. LnOs_4P_<12> (Ln=Eu,Gd,Tb) are ferromagnets. SmOs_4P_<12> is an antiferromagnet. Dy, Ho compounds are paramagnetic down to low temperature. YOs_4P_<12> is a new superconductor.
In this work, we found 16 new filled skuterudites and 4 new superconductors with skutterudite-type structure.
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