Effect of Sb substitution on structural and magnetic properties of MnBi based alloys

A series of MnBi1-xSbx alloys were prepared by a metallurgical method. The samples MnBi1-xSbx were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), vibrating-sample magnetometer (VSM). The effects of Sb substitution on the structural formation, electronic structure and magnetic property of MnBi were investigated experimentally and theoretically. We find that the introduction of Sb atoms may prevent the decomposition of Bi from MnBi, and thus help stabilize the low temperature phase (LTP) MnBi. In addition, first-principle calculations reveal that the saturation magnetization (Ms) and magnetic crystalline anisotropy constant (K) are increased upon increasing Sb-doping concentration, in contrast to a reduction of the Curie temperature (TC). Therefore, our findings could provide a promising route for enhancing the performance of MnBi permanent magnets.