Defect diagrams were derived for TiO2 for a wide range of O partial pressures involving the n-type regime, the p-type regime and the n–p transition regime at 973 to 1373K. The non-stoichiometry and related defect disorder of TiO2 were considered in terms of defects in both sub-lattices involving: O sub-lattice: O vacancies and Ti sub-lattice: Ti vacancies and Ti interstitials. Defect diagrams were derived in terms of defect concentrations (O vacancies, tri- and four-valent Ti interstitials) as a function of O partial pressure) at different levels of acceptor- and donor-type pre-imposed defects (Ti vacancies and foreign cations).

Defect Chemistry and Semiconducting Properties of Titanium Dioxide - II. Defect Diagrams. Bak, T., Nowotny, J., Rekas, M., Sorrell, C.C.: Journal of Physics and Chemistry of Solids, 2003, 64[7], 1057-67