La-Fe-M(M=Al, Si)化合物磁热性能研究进展

介绍了La-Fe-M(M=AI,Si)化合物在磁热性能研究方面的最新进展。具有NaZn13型晶体结构,含高浓度Fe的La-Fe—M(M=AI,Si)化合物为良好的软磁材料;用少量的Co替代化合物中Si,Al元素可以将化合物的居里温度提高至室温;对La(Fe1-yCoy)xSi13-x化合物,适量的Si,Co组合可使化合物在室温产生可与Gd5Si2Ge2比拟的磁热效应;加入适量的间隙原子H,也可使La(FexSi1-x)13在室温的磁热性能远远大于金属Gd;对含Si量低及含Si量高的La(FexSi1-x)13化合物在相转变点附近由温度和磁场诱导相变的本质做了详细阐述。

Advance in Research on Magnetocaloric Effect of La-Fe-M(M=Al, Si) Compounds

The recent progress in research on magnetocaloric effect for La-Fe-M(M=Al, Si) compounds was presented. La-Fe-M(M=Al,Si) compounds with NaZn_(13) structure and high content of Fe are excellent soft magnetic materials. The Curie temperature of compounds can be increased by substituting small amount of Co for Si, Al. The La(Fe_(1-y)Co_y)_xSi_(13-x) compounds with an appropriate combination of Co and Si can produce the giant magnetocaloric effect comparable with that for Gd_5Si_2Ge_2 at room temperature. The La(Fe_xSi_(1-x))_(13) with interstitial hydrogen atoms can also produce the giant magnetocaloric effect at room temperature, which is much greater than that for Gd. For La(Fe_xSi_(1-x))_(13) compounds with low Si content and high Si content, the nature of phase transition near Curie temperature induced by temperature and magnetic field was described in detail.