Mn_(1.27)Fe_(0.68)P_(1-x)Si_x合金的批量制备与磁热效应

Massive Preparation and Magneto-caloric Effect in Mn_(1.27)Fe_(0.68)P_(1-x)Si_x Alloys

采用机械合金化工艺,通过改变成型和退火条件,批量制备了Mn1.27Fe0.68P1-xSix(x=0.50,0.52,0.54,0.56)系列合金,并研究了合金的物相结构和磁热效应.室温(293K)XRD表明,该合金均为Fe2P型六角结构,空间群为P62 m.当x=0.50,0.52,0.54,0.56时,由M-T曲线可知,居里温度TC分别为231,260,277,310K,热滞ΔThys分别为4.7,3.4,2.9,2.4K;在变化的外磁场(0～1.5T)下,由M-B曲线求得合金的最大磁熵变ΔSmax分别为12.0,14.2,7.8,8.1J/(kg.K).

A massive preparation method and magneto-caloric effects in Mn1.27Fe0.68P1-xSix（x=0.50,0.52,0.54,0.56） alloys were investigated.The XRD results at room temperature show that the alloys crystallize in the Fe2P-type hexagonal structure with space group of P62m.The Curie temperature determined from the M-T curves is 231,260,277,310 K,the thermal hysteresis is 4.7,3.4,2.9,2.4 K for x=0.50,0.52,0.54,0.56,respectively.The maximal MCE obtained from the curves of isothermal magnetization for magnetic field change from 0 to 1.5 T is 12.0,14.2,7.8,8.1 J/（kg·K）,respectively.