Structural,elastic, electronic,phonon and thermal properties of Ir3Ta and Rh3Ta alloys

We have studied the structural, elastic, electronic, phonon and thermodynamic properties of Ir₃Ta and Rh₃Ta alloys, using ab initio calculations. For the L1₂ phase, we report the calculated lattice constants, bulk modulus and elastic constants, and these values are compared with previously published values. We also derive the elastic constants from the values of the slopes of the acoustic branches in the phonon dispersion curves. The band structures show that both materials are metallic. The phonon dispersion curves, and their corresponding total and projected densities of states, are obtained using a linear response in the framework of the density functional perturbation theory. The specific heat capacity at constant volume and different temperatures is calculated, and this aspect is discussed using the quasi-harmonic approximation.