Crystal structure and phase relations of Pr₂Fe₁₄B-La₂Fe₁₄B system

姚青荣^1,2，沈逸豪¹，杨鹏程¹，周怀营^1,3，饶光辉¹，邓建秋¹，王仲民¹，钟燕^1,3,4

1. School of Materials Science and Engineering,Guilin University of Electronic Technology2. School of Materials Science and Engineering,Central South University3. Guangxi Key Laboratory of Information Materials,Guilin University of Electronic Technology4. Guangxi Experiment Center of Information Science

摘 要：The crystal structure and phase relations of the Pr₂Fe₁₄B-La₂Fe₁₄ B system were investigated by X-ray powder diffraction（XRD）, differential scanning calorimetry（DSC） and scanning electron microscopy（SEM） equipped with energy dispersive X-ray spectroscopy（EDS）. The crystal structure parameters were determined by full-profile Rietveld refinements. The results revealed that all alloys of(Pr_1–xLa_x)₂Fe₁₄B crystallized the Nd₂Fe₁₄B-type structure with the space group P4₂/mnm and formed a continuous solid solutions between x=0.0 and 1.0. The lattice parameter a, c, unit-cell volume V and c/a ratio increased linearly with the La concentration. Determined by thermogravimetry analysis, the Curie temperature（T_C）, phase transition temperature and melting temperature of(Pr_1–xLa_x)₂Fe₁₄B decreased linearly upon the La content. Based on the results of DSC measurements and X-ray powder diffraction examinations, the phase diagram of the Pr₂Fe₁₄B-La₂Fe₁₄ B system was built up.

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