First-principle study of the polar TiC/Ti interface

The interface structure, work of adhesion and bonding character of the polar TiC/Ti interface have been examined by the first-principle density functional plane-wave pseudopotential calculation. Both Ti- and C-terminated interfaces including six different interface structures were calculated, which present quite different features. For the Ti-terminated interface, the interfacial Ti-Ti bond has a strong metallic and weak covalent character; for the C-terminated interface, the interfacial bond is the result of a strong polar covalent interaction between the Ti-3d orbital and the C-2p orbital. The work of adhesion of the C-terminated interface is nearly 9 J/m² stronger than that of the Ti-terminated interface. It is found that each termination has a relatively large work of adhesion, which is consistent with other polar interfaces.