Coercivity enhancement and magnetic property evaluation of Bi doped Mn2Sb

Mn2Sb is a well-known ferrimagnetic material, which has been investigated thoroughly to understand the effect of doping on its magnetic properties. Present work reports the synthesis of Bi doped Mn2Sb employing arc melting and melt spinning followed by characterization with a view to establish a correlation in the structure and magnetic properties. Bi doping in Mn2Sb lattice produces a significant change in the latter's magnetic properties, giving rise to a saturation magnetization of 27.2 emu/g (27.2 Am-2/Kg) and a high coercivity value of 3.4 kOe (279.2 kA/m), in comparison to Mn2Sb, which has a coercivity of 0.1 kOe (7.96 kA/m). Theoretical studies were carried out to understand the changes in magnetic properties. Ab-initio electronic and atomic structure calculations show that Bi atom occupies equally the MnI and MnII sites and this leads to ferromagnetic ordering, which results in enhancement of the saturation magnetisation. The coercivity mechanism has also been studied in detail; the large coercivity is attributed to the nucleation mechanism achieved via the inclusion of diamagnetic Bi particles in Mn2Sb