Theoretical Prediction on the Structural, Electronic, Mechanical, and Thermodynamic Properties of TaSi2 with a C40 Structure Under Pressure

Abstract

Abstract The structural parameters, electronic structures, and mechanical and thermodynamic properties of TaSi2 under different pressures have been completely explored by a combination of density functional theory and quasi-harmonic Debye model. Results show that our computed structural parameters and elastic constants are in consistency with available experimental findings and previous theoretical calculations. The electronic structures of TaSi2 under different pressures including band structures and density of states are reported. It turns out that TaSi2 should be metallic. The elastic constants Cij , bulk modulus B, shear modulus G, Young’s modulus E, Poisson’s ratio ν, B/G, Debye temperature θ, and wave velocities under pressures are also evaluated successfully. The calculated Cij obeys the Born–Huang stability criterion, which demonstrates that TaSi2 is mechanically stable under different pressures. More interestingly, the three-dimensional surface constructions and projections of E and B under different pressures are also systematically evaluated. With the increase of applied pressure, TaSi2 exhibits subtle anisotropy under zero pressure, and the anisotropy strengthened. Finally, the dependence of the thermodynamic properties on pressure/temperature is obtained and analyzed for the first time.