Mn-Fe-P-Si基磁制冷材料磁相变调控及磁热性能研究

Study on Phase-Transition Modulation and Magneto-Thermal Properties of Mn-Fe-P-Si Based Magnetic Cooling Materials

摘要: 磁热效应凭借其高能效、低能耗、低碳环保等优势，作为替代传统蒸汽压缩制冷的革新方案，研发高性能固态制冷系统已成为实现磁制冷技术工程化应用的核心突破口。然而，现有磁热材料固有的热滞后等问题严重影响了其磁热性能的大小与能量交换的效率，限制了其实际应用。本研究采用电弧熔炼、铜模喷铸和热处理的方法向Mn-Fe-P-Si材料中掺入适量的Zn，制备了不同成分的合金。借助扫描电子显微镜、X射线衍射仪、振动样品磁强计等仪器，深入表征样品的显微形貌、晶体结构、磁相变行为以及磁热性能，研究不同掺杂含量Zn对Mn-Fe-P-Si磁制冷材料相变的影响。最终得出结论，其温度调节可至室温附近，减小热滞，同时保持较大磁熵变，有利于材料在室温磁制冷中的应用。

Abstract: With its high energy efficiency, low energy consumption, low carbon and environmental protection advantages, magnetic thermal effect, as an innovative alternative to the traditional vapor compression refrigeration, the development of high-performance solid-state refrigeration system has become the core breakthrough to realize the engineering application of magnetic refrigeration technology. However, the inherent thermal hysteresis and other problems of existing magneto-thermal materials seriously affect the magnitude of their magneto-thermal properties and the efficiency of energy exchange, limiting their practical applications. In this study, alloys of different compositions were prepared by doping appropriate amount of Zn into Mn-Fe-P-Si materials by arc melting, copper mold spray casting and heat treatment. With the help of scanning electron microscope, X-ray diffractometer, vibrating sample magnetometer and other instruments, the microscopic morphology, crystal structure, magnetic phase transition behavior, and magneto-thermal properties of the samples were characterized in depth to study the effect of different doping content of Zn on the phase transition of Mn-Fe-P-Si magnetic cooling materials. It is finally concluded that its temperature adjustment can be up to near room temperature, reducing thermal hysteresis while maintaining a large magnetic entropy change, which is favorable for the application of the material in room temperature magnetic refrigeration.