Elastic properties of Ni2MnGa from first-principles calculations

Abstract

Elastic properties of Ni2MnGa in both austenitic and martensitic structures are determined by using ab initio methods based on density functional theory (DFT) within the spin-polarized generalized-gradient approximation. The tetragonal shear elastic constant C' takes a very small value in the austenitic phase, indicating the elastic instability results in a phase transition to martensitic structure. Isotropic mechanical properties such as bulk modulus, shear modulus, Young's modulus and Poisson's ratio are predicted. The trend of the Debye temperatures calculated for three structures of Ni2MnGa is comparable with that of the experiment. © 2010 Elsevier B.V. All rights reserved.