The effect of melt-spinning processing parameters on crystal structure and magnetic properties in Fe–Mn–Ga alloys

•Higher rotation speed can fabricate single bcc phase.•Higher ejection temperature can fabricate single bcc phase.•Fe2MnGa bcc phase transform into ferromagnetic hcp structure by thermal annealing.

We have succeeded to fabricate body-centered cubic (bcc) single phase of Fe–Mn–Ga alloys using melt-spinning technique. Heusler type L21 structure of Fe2MnGa alloy are predicted to have half-metallic properties, however bulk Fe2MnGa alloys crystallize into face-centered cubic (fcc) lattice with small admixture of bcc phase. By changing either ejection temperature or rotation speed of melt-spinning processing parameters, fcc or bcc lattice can be obtained from same precursor ingot. For stoichiometric Fe2MnGa as-spun alloy, super-lattice diffraction peaks indicative of L21 structure are observed from XRD measurements. The as-spun bcc alloys transform into ferromagnetic hexagonal lattice by thermal annealing.