Mixed structural face-centered cubic and body-centered cubic orders in near stoichiometric Fe2MnGa alloys

Magnetic and transport properties of near-stoichiometric metastable FexMnyGaz alloys (46<x<52, 17<y25, 26<z<30) with face-centered cubic (FCC), body-centered cubic (BCC), and two-phase (FCC+BCC) structures are investigated. The experimental results are analyzed in terms of first-principles calculations of stoichiometric Fe2MnGa alloy with the L21, L12, and the tetragonally distorted L21 structural orderings. It is shown that the pure BCC and FCC phases have distinct magnetic and transport properties. Two-phase Fe2MnGa alloys have magnetic and transport properties typical of the mixed BCC and FCC phases. Among the investigated alloys, Fe46Mn24Ga30 has a martensitic transformation accompanied by significant changes in its magnetic and transport properties.