La-Fe基NaZn_(13)型化合物的磁场诱导熵变研究  

Magnetic Field Induced Entropy Change for La-Fe Based NaZn_(13)-Typed Compounds

作　　者：张宏伟[1] 孙继荣[1] 胡凤霞[1] 王芳[1] 沈保根[1] 

机构地区：[1]中国科学院物理研究所磁学国家重点实验室,北京100080

出　　处：《中国稀土学报》2005年第4期385-393,共9页Journal of the Chinese Society of Rare Earths

基　　金：国家"863计划"(2001AA3204020);国家自然科学基金(50271082)资助项目

摘　　要：围绕具有一级磁性相变的La-Fe基NaZn13型化合物的磁场诱导熵变研究,从室温磁制冷目的出发讨论了材料研究和熵变机制。La-Fe-Si在190K附近5T磁场下的熵变值可达29J.kg-1.K-1。用少量Co替代Fe,可以获得室温附近5T磁场下熵变为15J.kg-1.K-1的大熵变材料。这类材料中的熵变主要由磁有序熵变和晶格熵变组成。分析了一级磁性相变体系中磁有序熵变和晶格熵变对总熵变的贡献,并发现大的熵变来源于被晶格贡献抵消后的磁有序熵变。Magnetic field induced entropy change was investigated for La-Fe based NaZn_(13)-type compounds with magnetic first-order phase transition. In view of magnetic refrigeration at room temperature, the developing of the materials and the understanding of the entropy change were reviewed. For La-Fe-Si compounds, the entropy change about 29 J·kg^(-1)·K^(-1) was obtained at 190 K under the magnetic field of 5 T. While a large entropy change of about 15 J·kg^(-1)·K^(-1) near room temperature under 5 T can be obtai...

关 键 词：La-Fe基NaZn13型化合物 熵变 一级磁性相变 稀土 

分 类 号：TB64[一般工业技术—制冷工程]