Abstract High purity MnBi magnetic low temperature phase (LTP) were prepared via induction melting, annealing and low energy ball milling. The effects of synthetic parameters and chemical compositions on phase purity and magnetic properties were systematically investigated. A homogenization heat treatment process was employed to increase the fraction of LTP MnBi, which showed notably high saturation magnetization (Ms) of up to 74.8 Am2/kg with the purity of 97 wt.% LTP MnBi. The purity of MnBi is strongly related to the amount of Mn and residual Bi in the annealed ingot. By controlling the residue, the highest phase fraction was obtained with the atomic ratio of Mn56Bi44. The maximum energy product (BH)max was recorded 11.7 MGOe under an applied magnetic field of 1.5 T at room temperature, making MnBi a promising rare-earth-free permanent magnet.

中文翻译：

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相纯度对提高Mn-Bi合金磁性能的影响

摘要 通过感应熔炼、退火和低能球磨制备了高纯度MnBi磁性低温相(LTP)。系统地研究了合成参数和化学成分对相纯度和磁性能的影响。采用均质化热处理工艺来增加 LTP MnBi 的含量，显示出高达 74.8 Am2/kg 的显着高饱和磁化强度 (Ms)，纯度为 97 wt.% LTP MnBi。MnBi 的纯度与退火锭中的 Mn 和残余 Bi 量密切相关。通过控制残留物，Mn56Bi44的原子比获得最高的相分数。在室温下 1.5 T 的外加磁场下记录的最大能量积 (BH)max 为 11.7 MGOe，使 MnBi 成为一种很有前途的无稀土永磁体。