在永磁体强磁场中Mn1.2Fe0.8P1-xSix系列化合物热磁发电研究∗

摘要

研究了处于永磁体强磁场中Mn1.2Fe0.8P1−xSix系列化合物的热磁发电性能,采用高性能球磨和固相烧结合成方法制备了Mn1.2Fe0.8P1−xSix系列化合物,并对该系列化合物的物相结构、磁性和热磁发电性能进行了测量.结果表明： Mn1.2Fe0.8P0.37Si0.63和Mn1.2Fe0.8P0.35Si0.65化合物是具有Fe2P型六角结构的一级相变软磁性材料,两者居里温度分别为334 K和348 K,处于工业余热温区.根据一级相变磁性材料在居里温度磁化强度发生突变这一特性,研制热磁发电演示装置,测量了Mn1.2Fe0.8P0.37Si0.63和Mn1.2 Fe0.8 P0.35 Si0.65这两种材料铁磁相变产生感应电流大小与线圈匝数、热磁发电材料质量、表面积、表面上温度梯度的关系.研究结果表明, Mn1.2Fe0.8P1−xSix系列化合物具有很好的热磁发电性能,有望成为热磁发电候选材料.%In this paper, we study the thermomagnetic power generation performances of compound series Mn1.2Fe0.8P1−xSix in a strong magnetic field of permanent magnet. The compounds are synthesized by using the high-energy ball milling and solid state reaction method. The crystalline structures, magnetic properties, and the thermomagnetic power generation performances of the compound series Mn1.2Fe0.8P1−xSix are measured. The results show that Mn1.2Fe0.8P0.37Si0.63 and Mn1.2Fe0.8P0.35Si0.65 are the compounds of a first-order phase transition and the soft ferromagnetic materials, and they are of Fe2P-type hexagonal structure, Curie temperatures of these compounds are 334 K and 348 K in the industrial waste heat temperature zone. According to this feature that temperature variation of the first-order phase transition material leads to a large change of magnetization at the Curie temperature, we design a demonstration device for thermomagnetic generator, and measure the relationships of induction current generated in ferromagnet phase transition with the coil turn number, mass and surface area of thermomagnetic generator material, and the gradient of surface temperature for compounds Mn1.2Fe0.8P0.37Si0.63 and Mn1.2Fe0.8P0.35Si0.65. The results show that the Mn1.2Fe0.8P1−xSix compound series possess the high performances of thermomagnetic power generation, and they are expected to be candidates of magnetic materials for thermomagnetic power generation.