Investigating the Effect of B, Sb, and Ge Elements on the Structural and Magnetic Properties of Rare Earth Elements -Free Permanent MnBi Magnets

The goal of this study was the investigation of the structural and magnetic characteristics of MnBi permanent magnets. In this regard, the mechanical milling and annealing processes were used for the synthesis of Mn45Bi50M5 (M= Sb, Ge, B) samples. Based on the results, the best annealing temperature and time for the formation of the highest value of MnBi ferromagnetic phase with optimum magnetic properties (Hc=1750 Oe and Ms= 12 emu/g) were recognized at 325 oC and 24 h, respectively. B, Ge, and Sb elements had a distractive effect on the stabilization of the MnBi ferromagnetic phase. Consequently, the samples containing B, Ge, and Sb showed lower magnetic characteristics in comparison with the Mn50Bi50 stoichiometric sample.