November 14, 2005
Journal Article

Negligible Magnetism in Excellent Structural Quality CrxTi1-xO2 Anatase: Contrast with High-Tc Ferromagnetism in Structurally Defective CrxTi1-xO2

Abstract

The mechanism of ferromagnetism in doped oxides is under active debate. We reexamine doped TiO2 anatase, using epitaxial Cr:TiO2 with excellent structural quality as a model system. In contrast to highly oriented but defective Cr:TiO2 (~0.5 µB/Cr), these structurally superior single crystal films exhibit negligible ferromagnetism. We show for the first time that charge compensating oxygen vacancies alone, as predicted by F-center mediated exchange, are not sufficient to activate ferromagnetism. Instead, the onset of ferromagnetism correlates with the presence of structural defects.

Revised: August 18, 2014 | Published: November 14, 2005

Citation

Kaspar T.C., S.M. Heald, C.M. Wang, J.D. Bryan, T.C. Droubay, V. Shutthanandan, and S. Thevuthasan, et al. 2005. Negligible Magnetism in Excellent Structural Quality CrxTi1-xO2 Anatase: Contrast with High-Tc Ferromagnetism in Structurally Defective CrxTi1-xO2. Physical Review Letters 95. PNNL-SA-45771. doi:10.1103/PhysRevLett.95.217203