The structure of a monolayer phase of TiOx on Pt(111) showing a zig-zag-like contrast was investigated by scanning tunnelling microscopy and density-functional calculations. Because of its peculiar defectivity, strongly dependent on the post-deposition thermal treatments, this system was an ideal model to study the structure and the evolution of defects in oxide nanophases. Atomistic models for each of the detected defects were obtained, which accurately reproduce the scanning tunnelling microscopy images showing that the experimentally observed defects essentially consist of Ti vacancies or irregular atomic distributions within the troughs exposing the bare substrate surface and that their formation energy was quite small, so that the system was under kinetic control under the given conditions of T and PO2.

Defect Evolution in Oxide Nanophases - the Case of a Zig-zag-Like TiOx Phase on Pt(111). Sedona, F., Granozzi, G., Barcaro, G., Fortunelli, A.: Physical Review B, 2008, 77[11], 115417