A first principles study on tetragonal distortion, magnetic property and elastic constants of Pd 2 CrAl Heusler alloy

Tetragonal distortion, magnetism and elastic constants of Pd 2 CrAl Heusler alloy are calculated by first principles based on the density function theory with projector augmented wave pseudopotential. Analysis of tetragonal distortion shows that there is a local minimum total energy at c/a ≈1.20, which corresponds to a stable martensitic phase. The magnetic moments of formula unit cells for L2 1 and tetragonal structure are 3.825 μ B and 3.512 μ B , respectively. There is very strong hybridization between Pd and Cr, and magnetism originates mainly from the 3d-t 2g and 3d-e g subbands of Cr atom in the two structures. Elastic constants of both L2 1 and tetragonal structure of Pd 2 CrAl satisfy their stability conditions, respectively.