Effect of Annealing Conditions on the Formation of a Nanocrystalline Phase in TiO_<i>x</i> Films

Abstract

Annealing of amorphous TiOx 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 the crystalline phase stops at an annealing temperature above 350°C. According to the results of X-ray phase analysis, the average crystallite diameter is about 23 nm. Electron microscopy studies have shown that, upon annealing, the near-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.