Effect of the Annealing Conditions on the Formation of a Nanocrystalline Phase in TiOx Films.

The annealing of amorphous TiO_x films obtained by electron-beam evaporation under atmospheric conditions at temperatures from 300 to 400°C is found to lead to the formation of an anatase crystalline phase. According to Raman spectroscopy data, the increase in the fraction of the crystalline phase stops at an annealing temperature above 350°C. According to the results of X-ray diffraction analysis, the average crystallite diameter is about 23 nm. Electron-microscopy studies show that, upon annealing, the surface layer (15 nm thick) crystallizes in the films, and TiO₂ nanocrystals with sizes from 4 to 10 nm are formed in the bulk. As the depth increases, the number of nanocrystals decreases. [ABSTRACT FROM AUTHOR]