Mixed Ce/Ti/Zr oxide thin films with a molar ratio of 0.5:0.25:0.25 were prepared using the sol-gel process and deposited on glass substrates by the dip coating technique. The effect of heat treatment temperature on surface morphology of the films was examined by atomic force microscopy AFM. The optical transmittance and reflectance of the films were measured over the spectral range from 350 to 1000 nm. The refractive index and extinction coefficient and thickness of the films were determined as a function of the heat treatment temperature. The refractive index increased from 1.51 to 2.02 at lambda = 600 nm and the extinction coefficient values increased from 0.006 to 0.094 while the thickness of the films decreased from 81 nm to 45 nm when annealing temperature increased from 100 degrees C to 500 degrees C. The results show that the optical properties and surface morphology of the mixed Cc/Ti/Zr oxide thin films were affected by annealing temperature. (c) 2006 Elsevier B.V. All rights reserved.