engleski

Transmission electron microscopy studies of nanostructurd TiO2 films on different substrates

A chemical vapour deposition (CVD) synthetic route to nanocrystalline titanium dioxide has been carefully investigated on different substrates. CVD was performed at low temperatures of 320 0C onto KCl crystal, Al foil, KBr pellet and freshly sliced MICA. The influence of substrate material on formation of films was studied in order to connect their improved intercalation properties. These films were thoroughly characterized with respect to their surface morphology, crystal structure, and the phase composition. Transmission electron microscopy (TEM) accompanied by selected area electron diffraction (SAED) was employed for structural characterization of TiO2 films, demonstrated that three of the films are solely composed of the anatase phase whereas in the film deposited onto Al foil also the brookite phase of TiO2 is present. The structural parameters of anatase were determined using the Rietveld refinement of electron diffraction data. By comparison of anatase lattice parameters with their corresponding bulk values, the significant deviation was observed and attributed to the thin film features and possible systematic errors introduced during the Rietveld refinement. The average grain size and the grain size distribution obtained by TEM were compared for different substrates.

titanium dioxide; aAverage grain size; chemical vapour deposition; transmission electron microscopy; rietveld refinement

nije evidentirano