Magnetic and calorimetric investigations of ferromagnetic shape memory alloy Ni₅₄Fe₁₉Ga₂₇

Abstract

We report results of magnetization and differential scanning calorimetry measurements in the ferromagnetic shape memory alloy Ni₅₄Fe₁₉Ga₂₇. This alloy undergoes an austenite–martensite phase transition in its ferromagnetic state. The nature of the ferromagnetic state, both in the austenite and the martensite phase, is studied in detail. The ferromagnetic state in the martensite phase is found to have higher anisotropy energy as compared with the austenite phase. The estimated anisotropy constant is comparable to that of a well-studied ferromagnetic shape memory alloy system NiMnGa. Further, the present study highlights various interesting features accompanying the martensitic transition (MT). These features suggest the possibility of either a premartensitic transition and/or an inter-MT in this system.