Influence of Fe and Co on phase transitions in Ni-Mn-Ga alloys

Abstract

Differential scanning calorimetry (DSC) and magnetic measurements were performed to study the influence of ferromagnetic 3-d transition elements Fe and Co on structural and magnetic properties of ferromagnetic shape memory alloys Ni2MnGa. Addition of Fe or Co on the Ni sites decreases the temperature of martensitic phase transition Tm, whereas addition of Co on the Mn sites results in a considerable increase of Tm. Magnetic measurement revealed that Curie temperature TC increases upon substitution of Fe or Co for Ni. This observation is of importance for design of high temperature ferromagnetic shape memory alloys.