Ab initio investigations of phonons and thermodynamic properties of ScZn and YZn in the B2 structure

We have performed an ab initio investigation of structural, elastic, electronic, lattice dynamical, and thermodynamic properties of ScZn and YZn in B2 structure. The calculations was conducted within the density functional theory and linear response theory using the pseudopotentials and a plane wave basis set. The completely minimized structural parameters and elastic constants of ScZn and YZn compounds are in excellent agreement with previous theoretical and experimental data. The calculated phonon dispersion relations for YZn concur very well with experimental data available for main symmetry directions. Through the full quasi harmonic model, in which the phononic effects considered, the thermodynamic properties such as temperature dependence of the isothermal and adiabatic bulk modulus, thermal expansion coefficients, heat capacities, entropy and free energy have been successfully calculated in the whole temperature range from 0 to 1000 K.