烧结温度对Mn1.2Fe0.8P0.73Ge0.27磁热性能及微观组织的影响

烧结温度对Mn_1.2Fe_0.8P_0.73Ge_0.27磁热性能及微观组织的影响

梁允田，王少博，徐国梁，张振路，刘丹敏^*

(北京工业大学 固体微结构与性能研究所，北京 100124)

摘  要  通过机械合金化结合等放电离子烧结技术，采用不同烧结温度制备名义成分相同的Mn_1.2Fe_0.8P_0.63Ge_0.27样品。使用X射线衍射仪(XRD)、差示扫描热量分析仪(DSC)、扫描电镜(SEM)研究了不同烧结温度对材料的成分、晶粒大小和磁热性能的影响。结果表明，材料均保持六方Fe₂P结构。随烧结温度的升高，居里温度下降，晶粒长大，熵变上升; 而杂相Ge₆Fe₃Mn₄向Mn_1.2Fe_0.8P_0.73Ge_0.27主相转化，而氧化物的含量基本不发生变化。

关键词  MnFePGe；烧结温度；磁热性能；晶粒大小

中图分类号：TB34；TG115.21   文献标识码：A   doi:10.3969/j.issn.1000-6281.2019.04.005

Magnetocaloric properties and microstructures of Mn_1.2Fe_0.8P_0.74Ge_0.26 alloy prepared with different temperature

LIANG Yun-tian，Wang Shao-bo，XU Guo-liang，ZHANG Zhen-lu，Liu Dan-min^*

(Institute of Microstructure and property of Advanced Materials, Beijing University of Technology, Beijing 100124, China)

Abstract  Mn_1.2Fe_0.8P_0.73Ge_0.27 alloys having the same initial component were prepared with different sinter temperatures by mechanical alloying and spark plasma sintering technique. The magnetocaloric properties and microstructures were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM). The results show that samples crystalize in the hexagonal Fe₂P-type structure. When the sintering temperatures rises, the Tc decreases, grain grows and the entropy change increases. The Ge₆Fe₃Mn₄ transformed to Mn_1.2Fe_0.8P_0.73Ge_0.27 with the sintering temperature rose, while no change with MnO content.

Keywords  MnFePGe；sintering temperatures；magnetocaloric property；grain size

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