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

我们一直在尝试成长Refe_4p_ <12>，RERU_4SB_ <12>，REOS_4SB_ <12>（re = la，ce，ce，pr，nd）的大型和高质量的单晶。在成年的晶体上，我们已经测量了基本的物理特性，并与许多研究组进行了对各种重要特性的合作研究。在它们中，我们简要报告了最重要的部分，尤其是基于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。通过在磁场下低温下的中子散射实验，对低温有序状态下的铁和抗磁磁成分进行仔细评估，这表明该相是四倍的相位。此外，发现有序状态是不稳定的，反对LA从运输，磁性和特定的热量测量中替换PR。 C-F杂交预期的有效质量增强。在NMR实验中，尚未观察到超导间隙中的相干峰值和节点结构。形成鲜明对比的是，从磁场中热导率的角度依赖性，各向异性间隙和点节点。此外，在超导阶段发现了两个不同的阶段。从系统的测量和对特定热量和磁化的分析中，发现γ_1是最有问题的CEF地面状态。（3）PRRU_4P_ <12>：它是基于1^<ST> pr pr的填充Skutterudite，表现出有趣的特征（非磁性金属禁用器过渡），并且是nesting模型（NM）拟议的。但是，尚未澄清。我们成功地检测了DHVA信号，并确定了FS。我们还进行了第一个成功的运输和特定的热实验，这表明只有NM无法解释M-1的过渡。较少的