Atomic force microscopy study on the anatase crystallization of long term stored Al2O3-TiO2-SiO2 coatings on glass

Atomic force microscopy was used to study the surface morphology of sol-gel derived Al2O3-TiO2-SiO2 coatings on microscope glasses. The coatings fresh ly annealed at 500 degrees C for 1 h were homogeneous on a nanoscale and sh owed typical glass pattern. After 10-month storage in air either before or after annealing, tetragonal-like crystallites were observed in coatings. Th e effects of chemical compositions and the storage process on the surface t opography and the crystallization of anatase were studied and discussed in combination with the XRD results of corresponding annealed gels. (C) 2000 K luwer Academic Publishers.