Oxygen Defect-Mediated Magnetism in Fe-C Codoped TiO2

The magnetic properties of the C doped and C-Fe codoped TiO2films fabricated by sol-gel and spin coating have been investigated combining experiments and first-principles calculations. All the samples exhibit the anatase crystal phase and the room temperature ferromagnetism. The values of the saturation magnetizations are in the order of Fe-C codoped TiO2> Fe-C codoped TiO2(annealed in O2) > C doped TiO2> C doped TiO2(annealed in O2). The calculated net moment values are in the order of Fe-C codoped TiO2> C doped TiO2with oxygen vacancies existing, in accord with the experimental results. The hybridization of Fe 3d, C 2p,and O 2p(nearest to the Fe defect) led to the spin split of Fe 3d, C 2p,and O 2pwhich contributed to the ferromagnetism.