Abstract:
TiO2 films have been deposited on silicon substrates by radio frequency magnetron sputtering of a pure Ti target in Ar/O-2 plasma. The TiO2 films deposited at room temperature were annealed for 1 h at different temperatures ranging from 400 degrees C to 800 degrees C. The structural, morphological, mechanical properties and the wetting behavior of the as deposited and annealed films were obtained using Raman spectroscopy, atomic force microscopy, transmission electron microscopy, nanoindentation and water contact angle (CA) measurements. The as deposited films were amorphous, and the Raman results showed that anatase phase crystallization was initiated at annealing temperature close to 400 degrees C. The film annealed at 400 degrees C showed higher hardness than the film annealed at 600 degrees C. In addition, the wettability of film surface was enhanced with an increase in annealing temperature from 400 degrees C to 800 degrees C, as revealed by a decrease in water CA from 87 degrees to 50 degrees. Moreover, the water CA of the films obtained before and after UV light irradiation revealed that the annealed films remained more hydrophilic than the as deposited film after irradiation. (C) 2010 Elsevier B.V. All rights reserved.