Structure, morphology and optical properties of multilayered sol–gel BaTi0.85Zr0.15O3 thin films

Continuous and homogeneous multilayered BaTi0.85Zr0.15O3 (BTZ) films were prepared by the sol–gel method and deposited on SiO2/Si substrates. X-ray diffraction analysis indicated the presence of well-crystallized, single phase perovskite BTZ phase only in the thicker, multilayer films (with more than three deposits). Beside the shrinkage of the unit cell, the increase of the deposits number in the BTZ films also induced an obvious surface smoothing, a higher compactness and a more uniform distribution of the average grain size, as observed by SEM and AFM investigations. The refractive index showed normal values indicating a high crystallinity degree for the films under investigation.