Structural and elastic properties of ZrC under high pressure

We have investigated the structural and elastic properties of ZrC under high pressures using the norm-conserving pseudopotentials within the local density approximation in the frame of density-functional theory. The calculated pressure dependence of the normalized volume is in excellent agreement with the experimental results. The (a − a0)/a0, (V − V0)/V0, the ductile/brittle, the elastic constants Cij (GPa), shear modulus C′, bulk modulus B, shear modulus G (GPa), Young's modulus E (Gpa), Poisson's ratio σ and anisotropy factor A as a function of applied pressure are presented. Through the quasi-harmonic Debye model, we also study the thermodynamic properties of ZrC. The thermal expansion versus temperature and pressure, the thermodynamic parameters X (X: Debye temperature or specific heat) with pressure P, and the heat capacity of ZrC at various pressures and temperatures are estimated.