Mixed films of TiO2-SiO2 deposited by double electron-beam coevaporation

We used double electron-beam coevaporation to fabricate TiO2-SiO2 mixed films. The deposition process included oxygen partial pressure, substrate temperature, and deposition rate, all of which were real-time computer controlled. The optical properties of the mixed films varied from pure SiO2 to pure TiO2 as the composition of the films varied accordingly. X-ray diffraction showed that the mixed films all have amorphous structure with a SiO2 content of as low as 11%. Atomic force microscopy showed that the mixed film has a smoother surface than pure TiO2 film because of its amorphous structure. Linear and Bruggeman's effective medium approximation models fit the experimental data better than other models.