Study on filled-skutterudite arsenide superconductors

填充方钴矿砷化物超导体的研究

• 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

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由于具有非常规的超导电性、多极有序性和近藤半导体等多种强关联电子行为而受到人们的广泛关注。然而，填充方钴矿砷化物迄今没有研究，因为样品的制备是相当困难的。我们开发了利用同步辐射在高温高压下“原位”观察结晶的实验技术。利用该技术，我们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地合成了高质量的单相填充方钴矿化合物CeRu_4As_<12>，PrRu_4As_<12>，SmFe_4As_<12>。CeRu_4As_3<12>具有半导体性质，激活能很小，为50K。磁性和热性质表明CeRu_4As_3<12>是一种近藤半导体。本文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。系统地比较了Pr基填充方钴矿化合物和La基填充方钴矿化合物，发现4f能级的晶体电场分裂对Pr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_3<12>显示亚铁磁性。

项目成果

Specific Heat of Filled Skutterudite-Type Compound TbRu_4P_<12> in Magnetic Fields

填充方钴矿型化合物TbRu_4P_<12>在磁场中的比热

• 发表时间: 2005
• 期刊: Physica B : Condensed Matter 359-361
• 作者: N.Ogita;R.Kojima;Y.Takasu;T.Hasegawa;T.Kondo;M.Udagawa;N.Takeda;T.Ikeda;K.Ishikawa;H.Sugawara;D.Kikuchi;H.Sato;C.Sekine;I.Shirotani;C.Sekine et al.
• 通讯作者: C.Sekine et al.

31P-NMR and μSR studies of filled skutterudite compounds SmT4P12 (T: Fe, Os)

填充方钴矿化合物 SmT4P12 (T: Fe, Os) 的 31P-NMR 和 μSR 研究

• DOI: 10.1016/j.physb.2006.01.086
• 发表时间: 2006
• 作者: K. Hachitani;H. Fukazawa;Y. Kohori;I. Watanabe;K. Kumagai;C. Sekine;I. Shirotani
• 通讯作者: I. Shirotani

Electrical and magnetic properties of Kondo semiconductor CeRu_4As_<12>

近藤半导体CeRu_4As_<12>的电学和磁学特性

• 发表时间: 2007
• 期刊: J. Mag. Mag. Mater. 310
• 作者: C. Sekine ;et. al.
• 通讯作者: et. al.

Specific heat properties of filled skutterudite compound PrRu*As*

填充方钴矿化合物 PrRu*As* 的比热特性

• 发表时间: 2007
• 期刊: J. Mag. Mag. Mater. 310
• 作者: T. Namiki ;et. al.
• 通讯作者: et. al.

Structural analysis of the filled skutterudite PrRu_4P_<12> at high pressure and low temperature.

填充方钴矿PrRu_4P_<12>高压低温结构分析。

• 发表时间: 2006
• 期刊: Physica B 378-380
• 作者: K. Takeda;et. al.;Atsushi Miyake et al.;Atsushi Miyake et al.
• 通讯作者: Atsushi Miyake et al.