Study on filled-skutterudite arsenide superconductors

填充方钴矿砷化物超导体的研究

基本信息

批准号：
17540309
负责人：
SEKINE Chihiro
金额：
$ 2.04万
依托单位：
Muroran Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17540309/
关键词：
skutterudite compound high pressure synthesis new material experiment for solid state physics electrical and electronic material superconductor crystal growth strongly correlated electron system 電子・電気材料

项目摘要

The filled skutterudite phosphides and antimonides have been actively studied because the compounds show wide variety of strongly correlated electron behaviors such as unconventional superconductivity, multipole ordering or Kondo semiconductor. However, filled skutterudite arsenides were not studied so far because a preparation of samples is quite difficult. We have developed the experimental technique of "in situ" observation for crystallization under high temperatures and high pressures using synchrotron radiation. Using the technique, we determined the synthesis conditions for several filled skutterudite arsenide and we have succeeded in synthesizing high quality single-phase samples of the filled skutterudite compounds CeRu_4As_<12>, PrRu_4As_<12>, SmFe_4As_<12> at high temperatures and high pressures. CeRu_4As_<12> exhibits a semiconducting behavior, with small activation energy of 50K. The magnetic and thermal properties suggest that CeRu_4As_<12> is a Kondo semiconductor. We measured specific heat of filled skutterudite superconductor PrRu_4As_<12> (Tc=2.3K) prepared under high pressure in detail. A systematic comparison among Pr-based filled skutterudite compounds and their La-based references reveals that crystalline electric field split of 4f levels play an essential role for superconducting properties in the Pr based-filled skutterudite superconductor. New compound SmFe_4As_<12> shows ferrimagnetism.

填充方钴矿磷化物和锑化物已被积极研究，因为这些化合物表现出多种强相关电子行为，例如非常规超导性、多极有序或近藤半导体。然而，由于样品制备相当困难，迄今为止尚未对填充方钴矿砷化物进行研究。我们开发了利用同步加速器辐射在高温高压下“原位”观察结晶的实验技术。利用该技术，确定了几种填充方钴矿砷化物的合成条件，并在高温、高压下成功合成了高质量单相填充方钴矿化合物CeRu_4As_<12>、PrRu_4As_<12>、SmFe_4As_<12>样品。压力。 CeRu_4As_<12>表现出半导体行为，活化能为50K。磁特性和热特性表明CeRu_4As_<12>是近藤半导体。我们详细测量了高压下制备的填充方钴矿超导体PrRu_4As_<12>(Tc=2.3K)的比热。对镨基填充方钴矿化合物及其 La 基参考材料进行系统比较表明，4f 能级的晶体电场分裂对于镨基填充方钴矿超导体的超导性能起着至关重要的作用。新化合物SmFe_4As_<12>表现出亚铁磁性。