First-principles calculations were employed to study the surface relaxation and electronic structure of the fully relaxed SrTiO3(001) O-vacancy surfaces with both Sr and Ti terminations. In contrast to the perfect surface, the larger surface rumples and smaller interlayer distances were found. Some in-gap Ti 3d states at about –1.13eV below the Fermi level were observed in the Ti-terminated surface caused by O vacancies. For the Sr-terminated O-vacancy surface, some in-gap Ti 3d states move into the bulk mid-gap region to become partially occupied. These theoretical results were in agreement with the experimental data.

Ab initio Study of Structural and Electronic Properties of SrTiO3 (001) Oxygen-Vacancy Surfaces. M.Q.Cai, Y.J.Zhang, G.W.Yang, Z.Yin, M.S.Zhang, W.Y.Hu, Y.G.Wang: Journal of Chemical Physics, 2006, 124[17], 174701 (7pp)