Spray pyrolysis deposition of nanostructured zirconia thin films

Polycrystalline zirconia thin films were obtained on silica substrates by the spray pyrolysis technique using a water/isopropanol solution of a precursor containing zirconium in the form of an anionic oxalate complex. The as-deposited products were amorphous. Crystallization with formation of homogeneous dense nanostructured cubic zirconia thin films occurred after heat-treatment in air at temperatures T=500–700 °C. In the range 700–1000 °C both cubic and monoclinic zirconia was present in the films, the C-ZrO2 content decreasing with temperature rise. Penetration of SiO2 from the silica substrate was registered in the films by X-ray photoelectron spectroscopy (XPS). A severe attack of the substrate by zirconia resulting in formation of ZrSiO4 was observed after annealing of the film at 1100 °C.