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Heusler 合金Ni-Mn-Ga和NaZn13型化合物La(Fe,Co,M)13,M=Si, Al 的巨大磁熵变
引用本文:胡凤霞,沈保根.Heusler 合金Ni-Mn-Ga和NaZn13型化合物La(Fe,Co,M)13,M=Si, Al 的巨大磁熵变[J].中国科学院研究生院学报,2002,19(2):192-197.
作者姓名:胡凤霞  沈保根
作者单位:中国科学院物理研究所凝聚态物理中心国家磁学重点实验室,北京,100080
基金项目:国家自然科学基金,北京市自然科学基金 
摘    要:在Heusler 合金Ni-Mn-Ga和NaZn13型化合物La(Fe,Co,M)13, M=Si, Al中很宽温度区间发现巨大磁熵变△S.这两种材料在室温区的磁熵变△S均显著地超过单质稀土Gd并达到著名的磁热效应材料Gd5Si2Ge2合金的磁熵变幅度. Heusler 合金Ni-Mn-Ga中的巨大磁熵变来源于具有一级相变特征的马氏结构相变.NaZn13型化合物La(Fe,Co,M)13, M=Si, Al中异常巨大的磁熵变与合金中的强的磁晶耦合相关,表现为居里温度附近晶格的巨大负膨胀.材料的低价格和其巨大磁熵变表明,Heusler 合金Ni-Mn-Ga和NaZn13型化合物La(Fe,Co,M)13, M=Si, Al在很宽的高温区,尤其在室温区作为磁制冷工质非常有吸引力.

关 键 词:磁熵变  磁制冷  Heusler  合金Ni-Mn-Ga  NaZn13型化合物

Great Magnetic Entropy Change in Heusler Alloys Ni-Mn-Ga and NaZn13-Type Compounds La(Fe,Co,M)13, M=Si, Al
Abstract.Great Magnetic Entropy Change in Heusler Alloys Ni-Mn-Ga and NaZn13-Type Compounds La(Fe,Co,M)13, M=Si, Al[J].Journal of the Graduate School of the Chinese Academy of Sciences,2002,19(2):192-197.
Authors:Abstract
Abstract:Very large magnetic entropy change △S in a wide temperature range was discovered in Heusler alloys Ni-Mn-Ga and NaZn13-type compounds La(Fe,Co,M)13, M=Si, Al. In room temperature range, the achieved △S in both materials significantly exceeds that of Gd and reaches that of Gd5Si2Ge2, which is well known for its giant magnetocaloric effect. The great △S in Heusler alloys Ni-Mn-Ga originates from the first-order martensitic-austensitic structural transition and the giant △S in La(Fe,Co,M)13, M=Si, Al is associated with a strong structural and magnetic interplay, characterized by a drastic lattice contraction at Curie temperature TC. The superiority of low cost and giant magnetic entropy change suggests that both Heusler alloys Ni-Mn-Ga and NaZn13-type compounds La(Fe,Co,M)13, M=Si, Al are promising candidates for magnetic refrigerants in an extended high temperature range, especially at room temperature.
Keywords:magnetic entropy change  magnetic refrigerant  Husler alloys Ni-Mn-Ga  NaZn13-type compounds
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