Synthesis of zinc titanates was carried out using a simple precipitation method followed by calcination at different temperatures to obtain different phases of the material. The phase transition characteristics, presence of functional groups, structural aspects and optical bandgaps with respect to calcination temperature were studied by thermal analysis, EDAX, FT-IR, powder XRD, Raman and UV-Vis spectroscopy respectively. The compound on heat treatment at 100 • C for 24 h showed broadened peaks in XRD. With increasing temperature of calcination, the compound appeared to turn to crystalline phase and cubic ZnTiO 3 phase was observed at 600 • C. Partial phase transformation of cubic phase ZnTiO 3 into hexagonal ilmenite type ZnTiO 3 was observed in the temperature range 700 • C to 900 • C. At 1000 • C both cubic and hexagonal ilmenite phases decomposed into cubic phase Zn 2 TiO 4 and rutile TiO 2. FT-IR showed M-O bonds in the range of 400 cm −1 to 700 cm −1. Raman spectra of cubic defect spinel ZnTiO 3 and cubic inverse spinel Zn 2 TiO 4 were found to be similar. The optical bandgap calculated using diffuse reflectance spectra was found to be in the range of 3.59 to 3.84 eV depending on calcination temperature.

a b s t r a c tPolycrystalline cubic In 2 O 3 thin films were deposited on the normal glass substrates by activated reactive evaporation method and systematically investigated the influence of oxygen partial pressure on the structural, optical, electrical and photoluminescence properties of the films. X-ray diffraction studies revealed that the films formed at oxygen partial pressure of 2 × 10 −3 mbar were nearly stoichiometric. The films formed at an oxygen partial pressure of 2 × 10 −3 mbar exhibited the electrical resistivity of 8.2 × 10 −4 cm, optical transmittance of 87% and the optical band gap of 3.62 eV. Two distinct emission peaks in the photoluminescence spectrum were observed at 415 and 440 nm in the visible region of the solar spectrum.

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