Preparation of low-temperature phase MnBi by sintering in vacuum

Abstract

A simple vacuum sintering system was set up to prepare low-temperature phase manganese-bismuth compound (LTP-MnBi). A mixture of Mn and Bi powders with 1:1 atomic ratio was sintered at 275 °C for 3, 6, 9 and 12 hours. The morphology of the sintered materials was investigated by SEM. The sintered product was further identified by XRD and energy dispersive spectroscopy and found to be LTP-MnBi, Mn and Bi. Sintering in vacuum could prevent the formation of manganese oxides. The magnetic properties of the sintered materials were characterized by using a vibrating sample magnetometer. The coercivity and the saturated magnetization were found to be 2.5 kOe and 42.4 emu/g, respectively. The maximum energy product of this magnetic materials was about 1.7 MGOe.