Mn1.25Fe0.75P1-xSix系列合金物相形成与磁热效应

Phase Formation and Magnetocaloric Effect in Mn1.25Fe0.75P1-xSix Alloys

摘要:

研究了Mn1.25Fe0.75P1-xSix（x=0.50, 0.52, 0.54, 0.56, 0.58, 0.60）合金的物相、热滞及磁热效应。通过XRD分析表明，合金主相均为Fe2P六角结构（空间群为P2m）。在不同Si含量时，合金中存在FeSi型 或Fe3Si型第二相。通过调节Si和P含量的比率，合金的居里温度随Si含量的增加成线性增加，从240 K到313 K。而合金的热滞在逐渐减小。当Si含量为0.58时，在外磁场变化为0~1.5 T下合金的最大等温磁熵变为8.6 J/kg·K。

Abstract:

Phase formation, thermal hysteresis and magnetocaloric effect in Mn1.25Fe0.75P1-xSix (x=0.50, 0.52, 0.54, 0.56, 0.58, 0.60) alloys have been investigated. X-ray diffraction analysis shows that the alloys crystallize in the Fe2P-type hexagonal structure (space group ) with second phase of FeSi or Fe3Si. By adjusting the content ratio of Si to P, Curie temperature increases linearly from 240 K to 313 K with the increasing of Si content, and the thermal hysteresis of the alloys decreases gradually. When the Si content is 0.58, the maximum value of the magnetic entropy change of the alloy is 8.6 J/kg·K for a field change from 0 to 1.5 T