In this paper we show that ferromagnetism can be induced in pure TiO2 single crystals by oxygen ion irradiation. By combining x-ray diffraction, Raman-scattering, and electron spin resonance spectroscopy, a defect complex, \emph{i.e.} Ti3+ ions on the substitutional sites accompanied by oxygen vacancies, has been identified in irradiated TiO2. This kind of defect complex results in a local (TiO6−x) stretching Raman mode. We elucidate that Ti3+ ions with one unpaired 3d electron provide the local magnetic moments.
@article{arxiv.0902.2092,
title = {Origin of magnetic moments in defective TiO2 single crystals},
author = {Shengqiang Zhou and E. Cizmar and K. Potzger and M. Krause and G. Talut and M. Helm and J. Fassbender and S. A. Zvyagin and J. Wosnitza and H. Schmidt},
journal= {arXiv preprint arXiv:0902.2092},
year = {2009}
}
Comments
4 pages, 4 figures, to be published at Phys. Rev. B