Mn_(1.2)Fe_(0.8)P_(0.48)Si_x化合物的结构和磁热效应

Structure and Magnetocaloric Effect in Mn_(1.2)Fe_(0.8)P_(0.48)Si_x Compounds

对Mn1.2Fe0.8P0.48Si0.52和非化学计量比Mn1.2Fe0.8P0.48Si0.49化合物的物相与磁热效应(MCE)进行了研究。结果表明:两种化合物均为Fe2P型六角结构(空间群为P-62m),化合物中含有少量的(Fe,Mn)3Si第二相。当Si的含量x由0.52降到0.49时,化合物的居里温度由268K升到282K,而Si含量的变化对化合物的热滞没有明显的影响。Mn1.2Fe0.8P0.48Si0.52和Mn1.2Fe0.8P0.48Si0.49化合物在外磁场变化为0~1.5T下的最大磁熵变分别为11.7J/kg·K和9.0J/kg·K。低成本的原料、较大的磁熵变使得Mn1.2Fe0.8P0.48Six化合物成为一种理想的室温磁致冷材料。

The structure and magnetic-entropy-change of Mn1.2Fe0.8P0.48Si0.52 and non-stoichiometric Mn1.2Fe0.8P0.48Si0.49 compounds were investigated. The results show that all these compounds crystallize in the Fe 2 P-type hexagonal structure (space group P-62m) with a small amount of (Fe, Mn) 3 Si phase. The Curie temperature of Mn1.2Fe0.8P0.48Six compounds increases from 268 K to 282 K with decreasing of Si content x from 0.52 to 0.49. Thermal hysteresis of the compounds does not change when decreasing the content of Si. The maximal magnetic entropy change is 11.7 and 9.0 J/kg·K for x = 0.52 and 0.49 respectively, under a magnetic change from 0 to 1.5 T. The large magnetocaloric effects and the low materials cost of Mn1.2Fe0.8P0.48Six compounds make them a promising candidate material for room-temperature magnetic refrigeration applications.