Dynamic elastic properties and magnetic susceptibility across the austenite-martensite transformation in site-disordered ferromagnetic Ni-Fe-Al alloy

ac susceptibility, sound velocity, and internal friction study of the martensitic transformation in melt-quenched (site-disordered) Ni55Fe20Al25 alloy unravels the irreversible thermoelastic changes (thermal hysteresis) that occur in the austenite phase in the premartensitic regime. In the heating cycle, the system retains the “memory” of the initiation and subsequent growth of the martensitic phase (at the expense of the parent austenite phase) that had taken place during the cooling cycle in the austenite-martensite phase coexistence region. These and other findings are discussed in this communication.