Sputtered rutile stoichiometric TiO2 nanocrystalline films

Titanium dioxide (TiO2) films were prepared at room temperature on silicon and glass substrates using DC reactive magnetron sputtering at the rate of 0.1 nms(-1) from a pure metal Ti target. X-ray diffraction (XRD) studies on freshly prepared samples showed a purely rutile phase. It is found from AFM that annealing of fresh TiO2 films at 550 degrees C for 30 min produced an increase in grain size by a factor of at least 1.5. X-ray photoelectron spectroscopies (XPS) gives correct ratio for purely TiO2 stoichiometry. Optical band gap was estimated to be 3.2 eV from UV-vis transmission spectra.