Xiang CHEN
金属学报(英文版)
The LaFe11.4Si1.6 compounds are prepared by arc-melting and then annealed at different high temperatures from 1323 K (5 h) to 1623 K (2 h). The powder X-ray diffraction (XRD) and microstructure observations show that large amount of 1:13 phase begins to appear in the LaFe11.4Si1.6 compound annealed at 1423 K (5 h). In the temperature range from 1423 K to 1523 K, the α-Fe and LaFeSi phases rapidly decrease to form 1:13 phase. The LaFeSi phase is rarely observed by XRD when the as-cast compound is annealed at 1523 K (5 h). With annealing temperature increasing to 1573 K, LaFeSi phase is detected again in LaFe11.4Si1.6 compound. In LaFe11.4Si1.6 compounds annealed at 1523 K (5 h), at 1373 K (2 h)+1523 K (5 h), and 1523 K (7 h)+1373 K (2 h), the impurity phases including small amount of α-Fe and LaFeSi phase reduce in turn. The magnetic measurement shows that LaFe11.4Si1.6 compounds annealed by above three processes keep the first-order of magnetic transition behavior, and TC are both at about 200 K. But the values of the maximal ΔSM(T, H) of has large difference, they are 9.94, 12.66, and 13.96 J/(kg•K) under a magnetic field of 0-2T, respectively.
关键词:
LaFe11.4Si1.6 compound
