Theoretical Prediction of Martensitic Transformation in Mn3Si Heusler Alloy

On the basis of ab initio calculations, we report the phase transformation of Mn 3 Si Heusler alloy from austenite to martensite structure. The total energy calculations suggest that the antiferromagnetic (AFM) spin configuration phase has the lowest energy and at a compressed volume Mn 3 Si becomes ferromagnetic (FM). We focus upon the distortion of the cubic Heusler structure which induces tetragonal structure with space group I4/mmm. We find out that, at c/a ratio of 1.60 and 1.38, the FM and AFM tetragonal structures become stable unlike the cubic ones. Consequently, martensitic transformation is expected to occur in both FM and AFM Mn 3 Si alloy. The stability of the martensite phase with respect to the austenite one is confirmed by calculating the density of states (DOS) at the Fermi level.