Elastic and electronic properties of point defects in titanium carbide

Abstract

A theoretical study of the electronic structures of TiC1-x and Ti1-xWxC (x = 0, 0.25) is presented. The density of states and crystal orbital overlap population calculations were used to interpret variations of elastic properties induced by carbon vacancies and alloying substitutions. Our results show why the introduction of vacancies into TiC reduces bulk moduli, while W substitution at a Ti site increases the elastic modulus. The effect of the point defects on the bonding in TiC is investigated by means of extended Hückel tight-binding band calculations.