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 CP and CV, 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.