Ab initio study of structural, electronic, and elastic properties of M_2SbP (M = Ti, Zr, and Hf)

摘要

This study predicts the structural behaviour of selected M2SbP compounds with the same structure as MAX phases. Zero pressure results of the lattice parameters, equilibrium volume, and the internal parameter ZM are calculated with an error less than 3%. Band structure, total and partial density of states were calculated and show the metallic character of these phases. Moreover we observed strong hybridising states; M d–P p, and M d–Sb p. The pressure dependence of the volume, and the lattice parameters were studied. The stiffness of M–P, and M–Sb bonds was discussed in term of relative length change under hydrostatic pressure. Hf_2SbP present the highest bulk modulus and the unidirectional elastic modulus C_(33) is slightly greater than C_(11).