Scanning tunnelling microscopy and spectroscopy were used to investigate the structure of rutile TiO2(100)-(1x3). The combination of these two techniques allows the identification of individual oxygen vacancies on the 1x3 reconstructed surface. These vacancies were found to occupy the top-most layer of the surface and to form one-dimensional arrays in the [001] crystallographic direction, with an intervacancy separation of 2.96Å and a typical length of ∼500Å. The scanning tunnelling microscopic data were consistent with a microfacet structural model proposed on the basis of grazing incidence X-ray diffraction data, modified to include the presence of O vacancies in the top layer.

Observation of Ordered Oxygen Vacancies on TiO2(100)1x3 using Scanning Tunneling Microscopy and Spectroscopy. Murray, P.W., Leibsle, F.M., Fisher, H.J., Flipse, C.F.J., Muryn, C.A., Thornton, G.: Physical Review B, 1992, 46[19], 12877-9