A Mechanism for TiO2Formation on Stepped TiN(001) from First-Principles Calculations

The adsorption of O2on the TiN(001) stepped surface and the consequent formation of surface oxide have been characterized using first-principles calculations. The adsorption and dissociation of O2on both the flat and the stepped surface are predicted to be spontaneous. Compared with the flat surface, however, the dissociation of O2on the stepped surface is predicted to be more exothermic. A formation mechanism for TiO2at the step is proposed that includes a nitrogen exit channel that enables further oxidation.