Ferromagnetism and local electronic properties of rutile Ti1-xFexO2 single crystals

An experimental evidence of the effects of iron on the magnetic and local electronic properties of TiO(2) single crystals is provided. When ferromagnetic rutile TiO(2) single crystals are doped with Fe ions, an enhancement of the saturation magnetic moment is observed, along with a transfer of electrons to Fe 3d and Ti 3d levels. Indeed, the analysis of core-level photoemission data shows that addition of iron has the effect (i) to promote electron charge transfer from O 2p band to localized Fe 3d orbitals and (ii) to reduce titanium ions by introducing 3d(1) electronic states in the otherwise empty 3d band of pure TiO(2). These effects, resulting from the incorporation of both transition-metal ion dopants and oxygen vacancies, increase the local magnetic moments that can contribute to long-range ferromagnetic ordering.