The optical properties of Ti-doped TiO2 nanoceramic films deposited by simultaneous rf and dc magnetron sputtering

The Ti-doped TiO2 (TiO2:Ti) nanoceramic films were deposited by simultaneous rf magnetron sputtering of TiO2 and dc magnetron sputtering of Ti. When dc power increased, TiO preferentially formed and the deposited films had lower O/Ti atomic ratio, especially at low substrate temperature. With the decrease of substrate temperature, the TiO2:Ti film had relatively high optical energy gap, therefore the absorption edge showed the blue shift. The nonlinear refractive indices of TiO2:Ti films prepared at different dc powers and substrate temperatures were measured by Moiré deflectometry, and were of the order of 10−8 cm2 W−1. By decreasing dc power and increasing substrate temperature, TiO2:Ti film exhibited lower surface roughness, higher linear refractive index and lower stress-optical coefficient.