Scanning tunnelling microscopy and spectroscopy were used to investigate the structure of the (100) - 1 x 3 surface of rutile. This combination of techniques permitted the identification of individual O vacancies on the 1 x 3 reconstructed surface. These vacancies were found to occupy the topmost layer of the surface and to form 1-dimensional arrays in the [001] crystallographic direction, with an inter-vacancy separation of 0.296nm and a typical length of about 50nm. The scanning tunnelling microscopic data were consistent with a micro-facet structural model, which had been proposed on the basis of grazing-incidence X-ray diffraction data, but which was modified so as to include the presence of O vacancies in the upper layer.

P.W.Murray, F.M.Leibsle, H.J.Fisher, C.F.J.Flipse, C.A.Muryn, G.Thornton: Physical Review B, 1992, 46[19], 12877-9