Ab-initio study of the polar SrTiO3(1 1 0) (1×1) surfaces

Various (1×1) terminations of the SrTiO3(1 1 0) polar surface are considered and their electronic and structural properties computed through first-principles calculations. The relative stability of terminations that differ by stoichiometry is compared by taking into account the influence of the chemical environment. In contrast with the metallic stoichiometric SrTiO termination, the nonstoichiometric ones are insulating and their stability comparable to that of the SrTiO3(1 0 0) surfaces. We thus argue that, among the (1×1) unreconstructed faces, some nonstoichiometric (1 1 0) orientations may be obtained in suitable O-poor environments.