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MM: Fachverband Metall- und Materialphysik
MM 19: Transport
MM 19.6: Vortrag
Dienstag, 15. März 2011, 15:15–15:30, IFW D
Study of 44Ti grain boundary self-diffusion in thin nanocrystalline TiO2 films — •Petr Straumal1,2, Sergiy Divinski1, and Gerhard Wilde1 — 1Institut für Materialphysik, Universität Münster, D-48149 Muenster, Germany — 2National University of Science and Technology "MISIS", 119049 Moscow, Russia
Titanium dioxide is known for its photo-catalytic properties and enhanced corrosion resistance in aqueous environments. Due to these properties TiO2 is very attractive material for light-induced self-cleaning glass, water-cleaning and producing hydrogen from water applications. Numerous works are dedicated to the diffusion of various dopants like niobium or chromium in TiO2 but so far, none studied the self-diffusion of titanium in nanocrystalline TiO2. The grain boundary self-diffusion in thin nanocrystalline TiO2 films is investigated. The oxide films are produced using a novel deposition method from metal-organic precursors at relatively low (400-500°C) temperatures. A relaxation annealing at 800°C was performed. The diffusion was measured in temperature interval between 200°C and 600°C by means of the radiotracer technique applying the 44Ti isotope and utilizing ion beam sputtering for sectioning. The diffusion was measured at different oxygen pressures. In addition, the microstructure and its possible evaluation during diffusion annealing was investigated using TEM. The results are discussed with respect of the relationship between grain boundary self-diffusion and the synthesis pathway, the oxygen pressure and resulting microstructure of the nanoscale functional oxide films.