Vacancy clusters at domain boundaries and band bending at the SrTiO3(110) surface

Z. Wang, X. Hao, S. Gerhold, M. Schmid, C. Franchini, U. Diebold

Institut für Angewandte Physik, Technische Universität Wien, 1040 Wien, Austria
Faculty of Physics and Center for Computational Materials Science, University of Vienna, 1090 Wien, Austria

Phys. Rev. B 90 (2014) 035436

Antiphase domain boundaries (APDBs) in the (n × 1) (n = 4,5) reconstructions of the SrTiO3(110) surface were studied with scanning tunneling microscopy, x-ray photoemission spectroscopy and density functional theory (DFT) calculations. Two types of APDBs form on each reconstruction; they consist of TixOy vacancy clusters with a specific stoichiometry. The presence of these clusters is controlled by the oxygen pressure during annealing. The structural models of the vacancy clusters are resolved with DFT, which also shows that their relative stability depends on the chemical potential of oxygen. The surface band bending can be tuned by controlling the vacancy clusters at the domain boundaries.

Reprints available from Ulrike Diebold (diebold at iap_tuwien_ac_at).

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