Room-temperature magnetostructural transition in Mn0.4Fe0.6NiSi compound

MM´X (M, M´ = transition metals, X = Si, Ge, Sn) intermetallic compounds have been recently concerned due to magnetoresponsive effects, for instance, field-induced martensitic transition (MT) and giant magnetocaloric effect (MCE). For stoichiometric MM´X compounds, structural transition and magnetic transition cannot been coupled. In recent years, many effective methods have been used to achieve the magnetoresponsive effects originated from magnetostructural transitions. Isostructurally alloying FeNiGe, MnFeGe and CoNiGe with MnNiGe resulted in the expected results. As reported, MnNiSi compound has a orthorhombic structure (TiNiSi-type) at room temperature, and the MT from Ni₂In-type hexagonal to TiNiSi-type orthorhombic structure occurs at 1210 K. Importantly, it is a typical ferromagnet with Curie Temperature as high as 615 K. Recently, by isostructurally alloying MnNiSi with FeNiGe and MnFeGe with stable Ni₂In-type structure, respectively the temperature of MT decreases and consequently magnetostructural coupling was achieved. In this paper, we reported the realization of magnetostructural transition in Mn_0.4Fe_0.6NiSi compound simply doped by Fe element.