高Si合金的结构和磁熵变

Structure and Magnetic Entropy Change in Rich Si Alloys

通过真空电弧炉熔炼法,制备LaFe12.1-xCo0.9Six B0.2(x=1.8,1.9,2.0)系列合金。利用XRD分析得到该系列合金的主相是NaZn13型结构,含有较强的α-Fe相。磁性测量表明该系列合金的居里温度均在室温附近,磁相变为典型的二级相变。利用Maxwell关系计算表明,该系列合金最大磁熵变均远小于相同化学配比,长时间高温退火合金的值。

The LaFe121-xCo0.9SixB0.2 （x=1.8, 1.9, 1.8） alloys were prepared by vacuum arc melting. An analysis of the XRD patterns showed that the LaFe12.1-xCo0.9SixB0.2 （x=1.8, 1.9, 1.8） alloys mainly consisted of the NaZn13-type cubic structure phase and α-Fe phase. Magnetic measurements showed that the Curie temperature of the alloys was near room temperature. The materials underwent a second-order magnetic transition. The maximal magnetic entropy changes of the LaFe121-xCo0.9SixB0.2 （x=1.8,1.9,1.8）alloys estimated by using the integrated Maxwell relation were smaller than those prepared by the traditional long-time annealing with the same kind of chemical composition for a magnetic field change from 0 to 1.5 T.