Specific Heat Study on Sm-based Filled Skutterudite Phosphides SmT4P12 (T=Fe, Ru and Os)
Specific Heat Study on Sm-based Filled Skutterudite Phosphides SmT4P12 (T=Fe, Ru and Os)
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DOI：
10.1143/jpsj.74.1030
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发表时间：
2005-03
影响因子：
1.7
通讯作者：
K. Matsuhira;Y. Doi;M. Wakeshima;Y. Hinatsu;H. Amitsuka;Y. Shimaya;R. Giri;C. Sekine;I. Shirotani
中科院分区：
文献类型：
--
作者：
K. Matsuhira;Y. Doi;M. Wakeshima;Y. Hinatsu;H. Amitsuka;Y. Shimaya;R. Giri;C. Sekine;I. Shirotani
用磁场比热法研究了高温高压合成的Sm基填充Skutterudite磷化物SmFe4P12、SMRU4P12和SMoS4P12。SmFe4P12在1.6K出现了铁磁相变的异常。SMRU4P12在16K出现金属-绝缘体相变，该相变由两个相继相变组成，这意味着轨道有序和反铁磁有序。SMO_4P_(12)在4.5K时由于反铁磁有序而出现明显的反常.讨论了Sm T4P12(T=Fe，Ru和Os)中这些相变的特征行为和晶态电场。有趣的是，SmFe4P12的磁熵在铁磁有序温度以下仅有0.16Rln2。这表明存在很强的自旋涨落效应。而SMRU-4P-12和SMOS-4P-12的磁熵变化在有序温度下接近Rln4。
Sm-based filled skutterudite phosphides SmFe 4 P 12 , SmRu 4 P 12 and SmOs 4 P 12 synthesized at high temperatures and high pressures have been studied by specific heat measurements in magnetic fields. SmFe 4 P 12 shows an anomaly at 1.6 K attributed to a ferromagnetic transition. SmRu 4 P 12 shows a metal–insulator transition at 16 K. This transition consists of two successive transitions, which suggests orbital and antiferromagnetic orderings. SmOs 4 P 12 shows a sharp anomaly at 4.5 K due to an antiferromagnetic ordering. We discuss the characteristic behavior of those phase transitions and the crystalline electric field state in Sm T 4 P 12 ( T =Fe, Ru and Os). Interestingly, the magnetic entropy of SmFe 4 P 12 have only 0.16 R ln 2 below the ferromagnetic ordering temperature. This suggests a strong spin fluctuation effect. On the other hand, the variation of magnetic entropy in SmRu 4 P 12 and SmOs 4 P 12 reaches to nearly R ln 4 below the ordering temperature.