Dependence of the relative stability between austenite and martensite phases on the atomic order in a Ni–Mn–In Metamagnetic Shape Memory Alloy

Abstract

The influence of the atomic order on the magnetic properties and the relative stability between phases in a Ni–Mn–In Metamagnetic Shape Memory Alloy has been studied through the analysis of the effect of the different quenching treatments on the magnetic and structural transformation temperatures. As a consequence of the variation on the degree of long-range atomic order, the martensitic transformation temperature highly increases with the increasing quenching temperature whereas the Curie temperature slightly decreases. The modification of the atomic order brought by the quenching process also promotes a reduction of the entropy change linked to the martensitic transformation. In turn, no evolution of the magnetization change at the martensitic transformation is detected. According to the Claussius–Clapeyron equation, the achievable shift of the martensitic transformation temperature with the applied magnetic field also depends on the degree of atomic order.