摘要
通过微观分析研究添加B对LaFe11．5Si1．5快淬带中a．Fe杂相的影响，并探讨LaFe11．5Si1．5，（x=0．5，0．7，1．0）化合物的磁相变和磁热效应。与LaFe11．5Si1．5比较，加入B后快淬薄带的显微组织显著细化，在较高B含量的快淬薄带中还得到了非晶态结构。经1000℃回火2～10h后，快淬试样均结晶为立方NaZn13型的La（Fe，Si）13化合物结构。含B快淬薄带经过较短时间的热处理就能得到单相结构，而且残留的a．Fe含量显著降低。磁性能测试表明，随着B含量的增大，LaFe11.5Si1.5Bx（x=0．5，0．7，1．0）化合物的居里温度略有升高；当B含量较低时，化合物具有一级磁相变特征并表现出与LaFe11．5Si1．5化合物相同的巨大磁热效应。
The influences of boron addition on secondary phase a-Fe in LaFe11.5Si1.5 melt-spun ribbons were investigated by＂SEM, TEM and XRD. The magnetic transition and magnetocaloric effect of LaFe11.5Si1.5Bx compound （x = 0.5, 0.7, and 1.0） were discussed. Compared with LaFe11.5Si1.5, the melt-spun ribbons have much finer microstructure after B addition, and even amorphous structure is obtained when B content is higher. The melt-spun specimens were crystallized into La（Fe,Si）13 compound structure of cubic NaZn13-type after annealing at 1000 % for 2-10 h. The annealing time can be reduced after B atom introduction to get single phase structure and the amount of residual a-Fe is decreased significantly. Magnetic property test show that Curie temperature of the LaFe11.5Si1.5Bx compound （x = 0.5, 0.7, and 1.0） increased slightly with B content increasing; the LaFe11.5Si1.5B0.5, i.e. low-B-content compound, exhibited first-order magnetic transition characteristics and had the same giant magnetocaloric effect with LaFe11.5Si1.5.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2009年第12期2238-2241,共4页
Rare Metal Materials and Engineering
关键词
NaZn13型金属间化合物
第二相
非晶相
巨磁热效应
NaZn13-type intermetallic compounds
secondary phase
amorphous phase
giant magnetocaloric effect
