Effect of Heat Treatment on Micromechanical Properties of Sprayed TiO ₂ Film on Ce-Doped Glass

Abstract Anatase TiO2 films were deposited on unheated Ce-doped soda–lime–silicate glass substrates by a spray technique from an anatase sol made in the laboratory. In order to investigate the micromechanical properties of TiO2 films, the deposited films were heated treated at: 350, 500 and 550°C, each for 1 h. X-ray diffraction spectra revealed a crystalline structure with an anatase phase and the average diameter of the grains increased from 21.4 to 31.2 nm as the temperature in the heat treatment rose from 20 to 550°C. The films as-deposited and heat-treated at 350°C were found to be smooth and relatively dense. Cracks appeared in TiO2 films when the heating temperature increased to 550°C. The results of nano-indentation test showed that when the heating temperature rose to 500°C, the TiO2 films were found to have nano-hardness and elastic modulus values of 1.1 and 30.8 GPa, respectively. These were the highest values recorded in this work. When the temperature reached 550°C, the nano-hardness and elastic modulus decreased due to the presence of cracks in the films.