Effect of nonstoichiometry and ordering on the period of the basis structure of cubic titanium carbide

We have examined the influence of nonstoichiometry and order-disorder phase transformations on the basis period (of type B 1) of the structure of titanium carbide TiC y (0.5< y <1.0). We found that ordering of titanium carbide TiC y with formation of superstructures of the type Ti Ti 2 C and Ti 3 C 2 leads to growth of the period of the basis crystal lattice in comparison with the disordered carbide. Taking the change in the lattice period into account, we discuss the question of the directions of the static displacements of atoms near a vacancy.