Formation of MnBi ferromagnetic phases through crystallization of the amorphous phase

We have succeeded in forming single-phase MnBi in its two ferromagnetic phases, the low-temperature phase (LTP) and the quenched high-temperature phase (QHTP). The formation process involves rapid solidification into the amorphous state followed by thermal annealing. The crystallization of the amorphous material involves a series of transformations before single-phase LTP (≳95 wt. %) is finally achieved at a temperature of 543 K. Further heating transforms LTP into its high-temperature structure at 635 K, which upon quenching to room temperature gives the QHTP. Some magnetic properties of LTP and QHTP are presented.