Etude de premier principes des propriétés physiques des composés antiperovskite: cas des composés XNS3 (X=Sb, Bi et As)

Abstract

In this work we present a first principles study of the structural, vibrational and thermodynamic properties of the compounds SbNSr3, BiNSr3 and AsNSr3 which crystallize in an antiperovskite simple cubic structure. Our calculations are performed using the pseudopotential method with plane waves (PP - PW) in the context of the density functional theory DFT, the term of the exchange potential and correlation is evaluated by the generalized gradient approximation (GGA). The phonon spectra as well as the densities of states of the DOS phonons are evaluated. The thermodynamic quantities (entropy, heat capacity, free energy and internal energy) are also calculated and evaluated as a function of the temperature.