Mn_(2-x)Fe_xP_(0.48)Si_(0.56)化合物的磁性与输运性能研究

Magnetic and Transport Properties of Mn_(2-x)Fe_xP_(0.48)Si_(0.56) Compounds

利用机械合金化和固态烧结的方法制备了Mn2-xFexP0.48Si0.56(x=0.55,0.60,0.65,0.70)系列化合物,研究其物相结构、磁热效应和输运特性.XRD和SEM测试结果表明,该系列化合物主相具有Fe2P型六角结构,主相成分基本与配方成分相同.磁性测量结果表明,该系列化合物经历一级相变过程,随着Fe含量的增加化合物的居里温度和最大磁熵变也增大,电阻率在相变处显示出反常行为.

Fe2P-type MnFe（P,Si） compound is a novel peculiar first-order phase transition material. In this work, a series of Mn2-xFexP0.48 Si0.26 （x = 0. 55,0. 60,0. 65,0. 70） compounds were prepared by high-energy ball milling and solid state reaction method, and the crystal structure, magnetocaloric effect and transport properties were investigated by using XRD, SEM and magnetic measurements. The XRD and SEM results show that the compounds crystallize in Fe2P-type hexagonal structure~ the main phase compositions are almost same as the nominal compositions. The magnetic results show that the compounds undergo a first-order phase transition, the Curie temperature and the maximal magnetic entropy change increase with increasing Fe content, the resistivity of the compounds shows an abnormal behavior at the transition.