Novel Magnetism and Superconductivity on Filled Skutterudite Compounds which Possess Rattling

具有嘎嘎声的填充方钴矿化合物的新型磁性和超导性

基本信息

批准号：
20740192
负责人：
YANAGISAWA Tatsuya
金额：
$ 2.58万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Young Scientists (B)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2009
项目状态：
已结题

项目摘要

Ultrasonic measurements on the Filled-Skutterudite compounds Pr_<1-x>NdxOs_4Sb_<12>(x=0.45, 0.25, 1.0)have been performed. Frequency dependences of elastic constant C11 were investigated with longitudinal ultrasonic frequencies varying between 34 to 245 MHz on these samples. A characteristic ultrasonic dispersion, which had also been observed in PrOs_4Sb_<12> (x=0) at around 30K, is also observed in the dilute systems and shifts gradually to higher temperature with increasing the Nd concentration x. On the other hand, the C11 of x=0.45 sample shows softening and levels off feature at T=0.25K. This result implies that the Nd3+ ion's degenerate CEF ground state is split due to some order even in the Pr^<3+> ion's contribution to SC. In addition, a magnetically robust elastic softening of C11 was found in the end material NdOs_4Sb_<12> (x=1.0) under magnetic field 2 T<H<10T at low temperature T<1K, which suggest a presence of the off-center tunneling as same as LaOs_4Sb_<12> and PrOs_4Sb_<12>. Above results imply that an origin of the heavy-fermion state of NdOs_4Sb_<12> could possibly be related to a degenerate quantum ground state due to the off-center degrees of freedom.

对填充方钴矿化合物Pr_<1-x>NdxOs_4Sb_<12>(x=0.45,0.25,1.0)进行了超声测量。研究了这些样品的弹性常数 C11 的频率依赖性，纵向超声波频率在 34 至 245 MHz 之间变化。在30K左右的PrOs_4Sb_ 12 (x＝0)中也观察到了特征超声分散，在稀体系中也观察到了这种分散，并且随着Nd浓度x的增加而逐渐转变至更高的温度。另一方面，x=0.45样品的C11在T=0.25K时表现出软化和平坦特征。该结果意味着Nd 3+ 离子的简并CEF基态由于某种顺序而分裂，甚至在Pr 3+ 离子对SC的贡献中也是如此。此外，在低温T<1K、磁场2 T<H<10T下，最终材料NdOs_4Sb_<12> (x=1.0)中发现C11具有强磁弹性软化，这表明存在偏心隧道效应与LaOs_4Sb_<12>和PrOs_4Sb_<12>相同。上述结果表明，NdOs_4Sb_<12>的重费米子态的起源可能与由于偏心自由度而导致的简并量子基态有关。

项目成果

期刊论文数量（0）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

A comparison of the normal and superconducting state properties of Pr(Os_Ru_x)_4Sb_ and Pr_Nd_xOs_4Sb_

Pr(Os_<1-x>Ru_x)_4Sb_<12> 和 Pr_<1-x>Nd_xOs_4Sb_<12> 常态和超导态特性比较

DOI：
发表时间：
2008
期刊：
影响因子：
0
作者：
P.
通讯作者：
P.

Elastic constants of U(Ru1-xRhx)2Si2

U(Ru1-xRhx)2Si2 的弹性常数

DOI：
发表时间：
2010
期刊：
影响因子：
0
作者：
Tatsuya Yanagisawa; Hitoshi Saito; Taichi Mayama; Hiroyuki Hidaka; Makoto Yokoyama; Hiroshi Amitsuka
通讯作者：
Hiroshi Amitsuka

Quadrupole Ordering in Clathrate Compound Ce_3Pd_Si_6

笼形化合物 Ce_3Pd_<20>Si_6 中的四极有序性