The electrical properties of pure Anatase were investigated by impedance spectroscopy as function of temperature and O partial pressure. The experimental results were fully explained by the point defect chemistry. A transition from predominant Schottky to Frenkel cation disorder was observed when the temperature increased and/or the O partial pressure decreased. The reduction enthalpies were near those obtained for Rutile in previous studies.

Electrical Properties and Defect Chemistry of Anatase (TiO2). Weibel, A., Bouchet, R., Knauth, P.: Solid State Ionics, 2006, 177[3-4], 229-36