2003/06/15 by W. T. Geng, Geng, W. T., K. S. Kim +1
Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #Catalytic Processes in Materials Science #FOS: Physical sciences #Geochemistry and Elemental Analysis #Materials Science (cond-mat.mtrl-sci) #ZnO doping and properties #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.cond-mat/0306389
5 pages, 3 figures; submitted to PRL on December 26,2002
arxiv created 2003/06/15 · openalex publication_date 2003/06/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
TiO2 anatase doped with Co has been recently reported to exhibit room-temperature ferromagnetism. Ab initio study on substitutional Co doping, however, yielded much larger magnetic moment for Co than experiment. Our calculations based on density-functional theory show that the substitutional Co ions incorporated into TiO2 anatase tend to cluster and then the neighboring interstitial tetrahedral sites become energetically favorable for Co to reside, yielding a local environment more like Co3O4 than CoTiO3. The interstitial Co destroys the spin-polarization of the surrounding substitutional Co but enhances the stability of the ferromagnetism significantly. In the absence of carriers, this room-temperature ferromagnetism can only be accounted for by superexchange interaction.