American Physical Society, Physical review B, 11(79)
DOI: 10.1103/physrevb.79.113201
Full text: Download
In this Brief Report 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, 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.