Effects of nonstoichiometry and ordering on the basic lattice constant of vanadium carbide VCy

Abstract

The effect of nonstoichiometry and ordering on the lattice constant a_B1 of the basic lattice of vanadium carbide VC_y(0.65 < y < 0.875) is studied. A change in the lattice constant of disordered carbide VC_y at the reduction of the carbon content is considered using the direction of static displacements of atoms near a vacancy. A model for the calculation of the basic lattice constant a_B1 of vanadium carbide is proposed taking into account nonstoichiometry and ordering. It is shown that the ordering of vanadium carbide VC_y with the formation of V₆C₅ and V₈C₇ superstructures results in an increase in the basic lattice constant as compared to disordered carbide.