Theoretical elastic stiffness and thermodynamic properties of zirconium dodecaboride from first principles calculation

The calculations based on density functional theory have been performed for the cubic zirconium dodecaboride (ZrB₁₂). Structural and elastic properties were obtained using Perdew-Burke-Enzerh (PBE) exchange- correlation functional. The lattice parameters and elastic constants at different pressures (0-30 GPa) have been calculated and total energies were used to determine the equation of state and free energy within the quasi-harmonic approximation. The agreement between the theoretical and experimental properties was found to be satisfactory. The thermodynamic properties including the normalized volume V/V₀, bulk modulus B, thermal expansion α, heat capacity C _P and C_V, Grüneisen constant γ and Debye temperature have been estimated at pressures from 0 to 50 GPa and temperatures from 0 to 2000 K, respectively. We anticipate that the calculated elastic and thermodynamic results can give an important reference especially to those not easy to be experimentally obtained.