The influence of boron on the adsorption of Ti and C on TiC surfaces

The first-principles calculations have been performed to study the influence of boron on the adsorption of Ti and C on different TiC surfaces. It is found that boron can be adsorbed on both TiC (001) and (111) surfaces. When boron is present and carbon supply is high during the preparation of TiC, boron can bond with carbon atoms to form B-C clusters on (001) surface, but the formation of them is less favorable than that of Ti-C clusters. However, under the low carbon-supply condition, both B-B and Ti-Ti clusters can be formed, and, once being formed, B-B clusters are more stable than the Ti-Ti ones. On Ti-terminated (111) surfaces, boron adatoms are more likely to be moved to form B-B clusters. The study of the diffusion of the adatoms on the surfaces demonstrates that boron adatoms can be more easily migrated on (111) surfaces, which further confirms the above results.