Phase stability, mechanical, electronic and thermodynamic properties of the Ga3Sc compound: An ab-initio study

In this paper, we present computational results of the structural, mechanical, electronic, elastic, and thermal properties of the binary intermetallic compound Ga3Sc by using the full potential linearized augmented plane wave method. The total energy calculations reveal that the cubic L1(2) structure for Ga3Sc is more stable than the tetragonal D0(22) and D0(23) structures. The ground-state structural and mechanical properties including the lattice constants (a, c), bulk modulus (B) and its pressure derivative (B') are estimated by different approximations. The single-crystal elastic constants C-ij are calculated. Similarly, the shear modulus (G(H)), Young's modulus (E), Poisson's ratio (nu), and the elastic anisotropy factor (A) are also derived for polycrystalline Ga3Sc using the Voigt-Reuss-Hill approximations. Analysis of the calculated elastic constants Cij, B/G ratios and the Cauchy pressure (C-12-C-44) shows that these compounds are mechanically stable and brittle in nature. The electronic and bonding properties are discussed from the calculations of band structures, densities of states and electron charge densities. The quasi-harmonic Debye model is used to predict thermodynamic properties of Ga3Sc at different temperatures and pressures.