Prediction of crystallographic characteristics of martensitic transformation in a Ni–Mn–Ga based Heusler alloy

The energy minimization theory was applied to analyze the crystallographic features of the martensitic transformation in the alloy Ni52.5Mn23.5Ga24 and the results obtained were compared with those determined by experiments. It is revealed that the index of the boundary between martensite variants belongs to the lattice plan family of {112}M and the orientation relationship between the martensite variant 1 and 2 is characterized by a rotation of 82.1° about [1 0 0]M1/[0 1 0]M2. The orientation relationship between the parent phase and the martensite features a rotation of approximately 4° about the c axis of the parent lattice from the position of the conventional Bain relationship.