The nature of the defect responsible for room-temperature ferromagnetism in Co-doped anatase TiO2 has remained elusive. Here we report atomic-resolution Z -contrast images of epitaxially grown Co0.03: TiO2 films showing that Co atoms are dispersed and occupy preferred interstitial sites. Density-functional calculations found that these sites are the lowest-energy configuration of Co in anatase and that O vacancies (VO), introduced by annealing, anchor the Co atoms into Co- Ti+3 -VO complexes. The calculated magnetic moment is in agreement with our measured value and the calculated Co x-ray absorption spectrum is in agreement with data published in the literature.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 7 Jul 2008|
ASJC Scopus subject areas
- Condensed Matter Physics