First-principles calculations on bonding characteristic and electronic property of TiC (111)/TiN (111) interface

Abstract

The bonding characteristic and electronic property of TiC (111)/TiN (111) interface were investigated by first-principles calculations in this work. 12 geometry structures of TiC (111) /TiN (111) interfaces with TiC or TiN terminations and three stacking sequences were established. The most stable interface configuration (C-terminated structure of TiC contacting with Ti-terminated structure of TiN with TL site) was selected to investigate the bonding nature and the electronic characteristic by the partial density of state (PDOS), charge density, charge density difference, charge density difference and Mulliken population analysis. The results show that the bonding nature at the interface is extremely similar to that in bulk materials, which shows both ionic and covalent characteristics. The PDOS of interfacial atoms of the most stable interface configuration is also extremely similar to those of their homologous bulks, which demonstrates that the electronic transition at the interface is smooth. The results of charge density and charge density difference indicate that the charge increased for N in TiN side is more than that for C in TiC side, which means the ionic bond in TiN is stronger than that in TiC coinciding with the result of Mulliken population analysis.