放电等离子体烧结（SPS）制备Mn1.2Fe0.8P0.75Ge0.25化合物及其磁热效应研究

摘要

采用机械合金化结合放电等离子体烧结技术,成功制备了Mn1.2Fe0.8P0.75Ge0.25室温磁制冷材料。采用XRD、VSM对烧结样品晶体结构和磁热效应（MCE）进行了研究。结果表明该化合物具有六方Fe2P型晶体结构,其热滞为4K,居里温度为292K,并且在居里点附近有较大的磁熵变,当外加磁场为1.5T时,最大磁熵变达到18.0J/（kg.K）,绝热温变达到2.7K。%Mn1.2Fe0.8P0.75Ge0.25 compound had been prepared by mechanical alloying and subsequent spark plasma sintering（SPS） technique.XRD and VSM were used to analyse the phase composition and MCE.The results show that the sintered bulk sample has a hexagonal Fe2P-type crystal structure,the thermal hysteresis of M-T is about 4K.The Curie temperature TC is 292K,and the maximum magnetic entropy change of the compound reaches to 18J/（kg·K） and adiabatic temperature change ΔTad is 4K in a field change from 0 to 1.5T.The properties of this compound meet room temperature magneto-caloric requirements.