Pressure effects on electronic, anisotropic elastic and thermal properties of Ti3AC2(ASi, Ge and Sn) by ab initio calculations

Abstract

The structural, electronic bonding characteristics, mechanical and thermal properties of Ti3AC2 (ASi, Ge and Sn) compounds under pressure from 0 GPa to 60 GPa are investigated by first-principles calculations. Whether under pressure or not, each compound reflects anisotropic elastic properties and their calculated bulk, shear and Young’s moduli are consistent with those determined theoretically and experimentally records. The quasi-harmonic Debye model is introduced in this work to investigate thermal properties of all compounds. Thermal expansion coefficient α of each compound under pressure is firstly discussed in the present paper. It is obviously that α decreases with the pressure increase and Ti3SnC2 shows the highest thermal expansion under pressure. The Debye temperature, CV and Grüneisen parameters are both obtained and the agreement between our calculations and other references are pretty good. Keywords: Ternary carbides, First-principles calculations, Electronic properties, Thermal properties