The structure, elastic and thermodynamic properties of Ti2GaC from first-principles calculation

In this work, the structure, elastic and thermodynamic properties of Ti2GaC at high pressure (P) and high-temperature (T) are studied based on the density functional first-principles. The lattice parameters and elastic constants are well consistent with some theoretical data and experimental results. The elastic constant of Ti2GaC increase monotonously with the increase of pressure (P), which demonstrates the mechanical stability of Ti2GaC at the pressure (P) from 0 to 200 GPa. Mechanical properties including Poisson's ratio (delta), Young's modulus (E), shear modulus (C) and bulk modulus (B), which are obtained from elastic constants C-ij. The ratio BIG value shows that Ti2GaC is a brittle material, but its enhancing ductility significantly with the elevate of pressure (P). The Gruneisen parameters (gamma), thermal expansion coefficient (alpha), heat capacity (C-v), elastic constant (C-ij), bulk modulus (B), energy (E) and volume (V) with the change of temperature (T) or pressure (P) are calculated within the quasi-harmonic Debye model for pressure (P) and temperatures (T) range in 1600 K and 100 GPa. Besides, densities of states and energy band are also obtained and analyzed in comparison with available theoretical data.