Exotic properties in the filled skutterudite compounds and their control by uniaxial pressure

填充方钴矿化合物的奇异特性及其单轴压力的控制

基本信息

批准号：
12440104
负责人：
SATO Hideyuki
金额：
$ 10.5万
依托单位：
Tokyo Metropolitan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12440104/
关键词：
filled skutterudites uniaxial pressure effect de Haas-van Alphen effect transport properties thermoelectric materials quadrupole order heavy fermion superconductivity Kondo effect 充填スクッテルダイト四重極子秩序 Shubnikov-de Haas振動四重端子相互作用重い電子

项目摘要

We have kept trying to grow large and high quality single crystals of REFe_4P_<12>, RERu_4Sb_<12>, REOs_4Sb_<12> (RE=La, Ce, Pr, Nd). On the grown crystals, we have measured basic physical properties and have made cooperative researches on various important properties with many research groups.Among them, we briefly report the most important part, especially on Pr-based systems.(1) PrFe_4P_<12> : Non-magnetic CEF ground state was further confirmed by μSR measurement. A careful evaluation of the ferro- and antiferro-magnetic components in the low temperature ordered state by neutron scattering experiments at low temperatures under magnetic fields revealed the phase to be a quadrupole one. Furthermore, the ordered state was found to be unstable against a replacement of Pr by La from transport, magnetic and specific heat measurements.(2) PrOs_4Sb_<12> : From de Haas-van Alphen (dHvA), its Fermi surface was found to be close to that of the reference compounds LaOs_4Sb_<12>, reflecting the … More localized nature of f-electrons, while we confirmed highly enhanced effective mass expected from c-f hybridization. In a NMR experiment, neither coherence peak nor node structure in superconducting gap has been observed. On the contrary, from the angular dependence of thermal conductivity in magnetic fields, anisotropic gap with point nodes. In addition, there found two different phase with different symmetries in the superconducting phase. From systematic measurements and analyses of specific heat and magnetization, Γ_1 was found to be the most probable CEF-ground state.(3) PrRu_4P_<12> : It is the 1^<st> Pr-based filled skutterudite exhibiting interesting feature (non-magnetic metal-insulator transition) and a nesting model (NM) was proposed to be an origin. However, nothing has been clarified yet. We have succeeded in detecting dHvA signal, and determined the FS. We have also performed the first successful transport and specific heat experiment, which suggests only the NM cannot explain the M-I transition. Less

我们一直在尝试生长大尺寸、高质量的REFe_4P_<12>、RERu_4Sb_<12>、REOs_4Sb_<12>（RE=La、Ce、Pr、Nd）单晶，并在生长的晶体上测量了基本物理性质。并与多个研究小组就各种重要性质进行了合作研究。其中，我们简要报告了其中最重要的部分，特别是基于Pr的系统。(1) PrFe_4P_<12>：通过μSR测量进一步证实了非磁性CEF基态，通过在磁场下的低温中子散射实验对低温有序态的铁磁和反铁磁成分进行了仔细评估，揭示了相。此外，从输运、磁力和比热测量中发现，有序态对于 La 取代 Pr 是不稳定的。(2) PrOs_4Sb_<12> ：从 de Haas-van Alphen (dHvA) 中，发现其费米面与参考化合物 LaOs_4Sb_<12> 的费米面接近，反映了 f 电子的局域性质，同时我们证实了预期的有效质量高度增强在核磁共振实验中，没有观察到超导间隙中的相干峰和节点结构，相反，从磁场中热导率的角度依赖性来看，此外，通过对比热和磁化强度的系统测量和分析，发现超导相中存在两种不同对称性的相，即最可能的CEF基态。(3) PrRu_4P_。 <12>：这是第1^<st>镨基填充方钴矿，表现出有趣的特征（非磁性金属-绝缘体转变），并提出了嵌套模型（NM）然而，我们还没有成功地检测到 dHvA 信号，并确定了 FS，这表明只有 NM 无法解释 M-I 转变。