中文摘要：

采用机械合金化工艺制备了非计量比Mn1.27Fe0.68P0.44Si0.56化合物,并利用X射线衍射（XRD）、磁性测量仪研究了样品的晶体结构和磁性能。室温XRD分析结果表明,样品呈单相Fe2P型六角晶体结构。磁测量结果表明该化合物的居里温度为297 K,热滞为2K,0-1.5 T外磁场下的最大磁熵变为5.0 J/kg·K。比热测量（DSC）结果表明该化合物升温的吸热峰出现在295K,热滞为2.1K,与磁测量结果基本一致。可见DSC方法可以快速准确地确定样品的相变与热滞。

英文摘要：

Mn1.27Fe0.68P0.44Si0.56 compound was prepared by mechanical alloying process. The crystal structure and magnetic properties of the sample were characterized using X-ray diffraction technology and magnetic measuring measurement. XRD-pattem measured at room temperature reveals that the sample is of single phase with the Fe2P-type hexagonal structure. The result of magnetic measurement reveals that Curie temperature of the sample is 297 K, thermal hysteresis is 2K, and maximum value of magnetic entropy change is 5.0 J/kg·K. The specific-heat measurement （DSC） shows that the transition temperature on heating is 295K and the thermal hysteresis is 2.1 K, which is consistent with the result of magnetic measurement. Thus, DSC measurement is a fast and appropriate method to determine the phase transition temperature and the thermal hystersis.