Elasticity, Anisotropy and Magnetism of Anti-perovskite M3AlC (M=Ti, Fe, Sm) from First-Principle Calculations

Elasticity, anisotropy, and magnetism of anti-perovskite M3AlC (M=Ti, Fe, Sm) have been calculated and investigated via non-relativistic density functional theory. And the elasticity constant, elastic modulus, Poisson ratio, and Cauchy pressure of three structures have been obtained. Based on the Poisson ratio, Pugh modulus ratio, and Cauchy pressure, bonding attributes of the three materials have been analyzed. The result showed that Ti3AlC is a brittle material with high degrees of strength, rigidity, and hardness, and Sm3AlC and Fe3AlC possess excellent toughness. Based on the universal elastic anisotropy index A (U) , anisotropy fraction ratios A (B) , A (G) , and A (E) ,and Zener factor A, it showed that all three M3AlC structures demonstrated elasticity and anisotropy. The elasticity and anisotropy of the three M3AlC structures has been illustrated in three-dimensional images of the elastic modulus. Compared with Ti3AlC and Fe3AlC, Sm3AlC has a significantly higher level of anisotropy. Moreover, in this paper, the magnetism of transition metal Fe and rare earth element Sm in the M3AlC structure has been compared and analyzed from the perspective of the electronic structure and population analysis.