室温磁致冷材料的研究进展

Recent Development in Room- temperature Magnetic Refrigerating Materials

对室温磁致冷材料的最新进展作了综合报道,主要包括Gd、Gd-Si-Ge、La-Fe-(Si、Al)、Mn-As-Sb、Mn-Fe-P-As几个化合物系列。Gd,居里温度294K,其磁热性能在所有纯金属中最好;Gd5Si2Ge2,居里温度274K,在此温度处具有巨磁热效应;在La-Fe-Co-Si、La-Fe-Co-Al化合物中,改变Co的含量可以使化合物的居里温度得到调整,其磁热性能可以与Gd比拟甚至超过Gd;MnFeP0.45As0.55,居里温度308K,具有巨磁热效应,磁热性能远远超过Gd。在MnAs1-xSbx化合物中,随Sb(0<x<0.1)含量的变化,材料的居里温度在318K～230K连续调整,但仍保持大的磁热效应。最后指出将居里温度不同的材料进行合理组合而得到复合材料,以拓宽材料的磁热效应曲线是室温磁致材料研究发展的一个重要途径。

In this review, the recent development in room-temperature magnetic refrigerating materials is presented. These materials include Gd, Gd-Si-Ge, La-Fe-(Si, Al), Mn-As-Sb and Mn-Fe-P-As compounds. The magnetocaloric effect of Gd is the greatest in all pure metals; Gd5Si2Ge2 has the giant magnetocaloric effect with a Cure temperature of 274 K; the Cure temperatures of La-Fe-Co-Si and La-Fe-Co-Al compounds can be adjusted by changing the content of Co, and their magnetocaloric effect can be comparable with or even better than that of Gd; MnFeP0.45As0.55, whose Cure temperature is 308K, has the giant magnetocaloric effect which is much more than that of Gd; although the Cure temperatures of MnAs1-xSbx (0 < x < 0.1) compounds vary from 318 K to 230 K by changing the content of Sb from 0 to 0.1, the magnetocaloric effect of the compounds can not be reduced. One of the important ways to improve the room-temperature magnetic refrigerating materials is to fabricate the composite material by combining materials with different Cure temperatures to widen the peak width of the magnetocaloric effect curve.