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  Skryshevskyy, V.A.; Dittrich, Th.; Rappich, J.: Infrared - active defects in a TiO₂ mixture of coexisting anatase and rutile phases. Physica Status Solidi A 201 (2004), p. 157-161

10.1002/pssa.200306734

Abstract:
Anodic oxidation of Ti has been used to produce layers of TiO2 consisting of anatase and rutile or a mixture of both. While the anatase phase of TiO2 is formed at lower anodization potentials, the formation of the rutile phase starts at potentials above 100 V due to electrical breakdowns. Defects with broad optical absorption in the infrared range are generated only in anodic TiO2 layers with coexisting anatase and rutile phases under ultraviolet illumination in water containing atmosphere. These defects disappeared by annealing at about 400°C for 30 min. The reversible defect reaction takes place in the surface regions between the anatase and rutile phases.