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.