Microstructure and Magnetic Properties of Mn55Bi45 Powders Obtained by Different Ball Milling Processes

Metals

Wei Lu¹  Dong Pan²  Xiang Li²  Dan Batalu³  Zhen Xiang³ 

[1] Application for Metal-Functional Materials, School of Materials Science and Engineering, Tongji University, Shanghai 200092, China;School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China;;Shanghai Key Laboratory of Development &

关键词: Mn₅₅Bi₄₅ powders;    low-energy ball milling;    surfactant;    particle size;    coercivity;    microstructure;    magnetic properties;   

DOI  :  10.3390/met9040441

来源: DOAJ

【 摘 要 】

Low-temperature phase (LTP) MnBi is considered as a promising rare-earth-free permanent magnetic material with high coercivity and unique positive temperature coefficient of coercivity. Mn₅₅Bi₄₅ ribbons with high purity of LTP MnBi phase were prepared by melt spinning. Then, Mn₅₅Bi₄₅ powders with different particle size were obtained by low-energy ball milling (LEBM) with and without added surfactant. The coercivity is enhanced in both cases. Microstructure characterization reveals that Mn₅₅Bi₄₅ powders obtained by surfactant assisted low-energy ball milling (SALEBM) have better particle size uniformity and show higher decomposition of LTP MnBi. Coercivity can achieve a value of 17.2 kOe and the saturation magnetization (M_s) is 16 emu/g when Mn₅₅Bi₄₅ powders milled about 10 h by SALEBM. Coercivity has achieved a maximum value of 18.2 kOe at room temperature, and 23.5 kOe at 380 K after 14 h of LEBM. Furthermore, Mn₅₅Bi₄₅ powders obtained by LEBM have better magnetic properties.

【 授权许可】

Unknown