Effects of annealing on titanium dioxide structured films

Titanium dioxide is a material of interest for optically active structured films due to its high index of refraction and transparency across the visible wavelength range. A variety of films, consisting of different structures, were deposited by reactive electron beam evaporation using the glancing angle deposition process. Samples of these films were annealed at 500 degreesC for 3 hours in air. The structures of both as-deposited and annealed films were examined by scanning electron microscopy, X-ray diffractometry, and transmission electron microscopy. It was found that as-deposited films were amorphous with a very fine structure. The annealed films were found to be polycrystalline anatase and had lost their fine structure. in addition, the optical properties of the films were examined by spectrophotometric transmission measurements, wherein it was found that the annealing caused a significant transmission increase across the visible spectrum. (C) 2004 Published by Elsevier B.V.