Growth of ultrathin titanium oxide films on Ag(110)

Titanium oxide films grown on Ag(110) have been investigated by low-energy electron diffraction (LEED), photoelectron spectroscopy (PES), and X-ray absorption spectroscopy (XAS). As Ti atoms were deposited on Ag(110) in O2 at 5.0 × 10−6 Torr and the surface was subsequently annealed at 500 °C for 30 min, a film with a (1×1) periodicity with respect to Ag(110) was formed. The core-level PES study showed that the film was composed of TiO2 in which 1/6 of Ti atoms are reduced to Ti3+. The film gave a (1×1) LEED pattern when the thickness was less than 1 nm. The O K-edge and Ti L-edge XAS measurements showed that each Ti atom in the film was coordinated by 6 O atoms forming a distorted octahedron, as in the case of rutile and anatase TiO2. Analyses of XAS results suggested that the long-range order of the film was similar to that of anatase TiO2.