Stress- and magnetic field-induced entropy changes in Fe-doped Ni-Mn-Ga shape-memory alloys

Isothermal stress- and magnetic field-induced entropy changes in a Fe-doped Ni-Mn-Ga alloy have been measured in the limits of low applied stress and magnetic field. We have obtained that in this limit while elastocaloric is conventional, giving rise to an increase of entropy when a stress is applied, magnetocaloric effect is inverse, which means that entropy decreases by application of an applied magnetic field. This inverse effect is a consequence of the magnetostructural coupling driven by the martensitic transition.