Energy Levels of Iron Group Impurities in TiO₂

Abstract

By changing the location of Fermi level of TiO 2 by lithium doping, ESR signals of some transition metal impurities in this crystal were pursued. The conclusions are: the Cr 3+ , Mn 4+ and Fe 3+ levels are near or overlapped with the valence band, the V 3+ , Mn 2+ and Fe 2+ levels are near the conduction band, the Cr 2+ level is above the bottom of the conduction band, the Mn 3+ and V 4+ levels are near the center of the band gap, and consequently the energy level separation between Mn 2+ and Mn 3+ and that of V 3+ and V 4+ are small ( i. e. less than 2 eV). The calculated level structures with the aid of these experimental results are related to the metallic and insulative nature of magnetic oxides, in general.