XAS AND XRD STRUCTURAL STUDIES OF TITANIUM-OXIDE THIN-FILMS PREPARED BY ION-BEAM-INDUCED CVD

The structure of TiO2 thin films prepared by ion beam induced chemical vapor deposition has been analysed by XRD and EXAFS/XANES spectroscopy. The results show that the film structure is dependent on the preparation conditions. Thus, bombardment with O2+ ions of 1 KeV at 300 K produces an amorphous structure that yields pure anatase after calcination at 823 K. By contrast, bombardment with 10 KeV ions at 300 K produces an amorphous film which at short ranges reproduces an atomic arrangement similar to that of the rutile structure. Calcination at 823 K of this film yields pure rutile. Bombardment with 1 KeV ions at 573 K produces a film which after calcination at 823 K yields a mixture of anatase and rutile. A detailed analysis of the EXAFS and XANES spectra enables a better characterization of the amorphous and crystalline structure of these films and provides a better understanding of the crystallization processes during calcination.