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

The Al-doped TiO₂ (TiO₂:Al) nanoceramic films were deposited by simultaneous rf magnetron sputtering of TiO₂ and dc magnetron sputtering of Al. The advantage of this method is that the Al content could be independently controlled. Al₂O₃ was favorable to form with decreasing Al content. The nanocrystallinity was enhanced by increasing the Al contents, because the increase of Al contents resulted in that the deposited films to be nearly stoichiometric. The morphologies of TiO₂:Al films were significantly affected by Al contents. The nonlinear refractive index of TiO₂:Al film on the glass substrate was measured by Moiré deflectometry, and was of the order of 10^?8 cm² W^?1. As Al content increased, the TiO₂:Al film had high VIS-IR transmission, high optical energy gap, high linear refractive index and low porosity.