Influence of impurities and vacancies on the electronic properties of TiSixNy metastable cubic phases

The influence of structural vacancies and oxygen impurities on the electronic properties of TiSixNy metastable cubic solid solutions is investigated using self-consistent linearized muffin-tin-orbital (LMTO) band-structure calculations. The equilibrium lattice constants are calculated for TiN1.0, TiSi0.25N0.75, TiSi0.25N0.50, and TiSi0.25N0.50O0.25. The main features of the total and partial densities of states of nitro,oen-deficient and oxygen-containing solid solutions are examined in terms of changes in local interactions between metallic centers and their nearest nei,ghbor surrounding. On the basis of calculated cohesion and incorporation ener,gies, the influence of defects on the stability of the B1 structure of TiSixNy solid solutions is discussed.