Structural, optical and magnetic properties of W-doped TiO 2 : Theory and experiment

Based on the density functional theory method, the ab initio calculation with GGA+U was performed to investigate the electronic structure and properties of W-doped TiO2. The results indicated that W-doping induced ferromagnetism and shifted the absorption spectra to visible light region. The ferromagnetism derived from the spin-split of O 2p and W 5d caused by p–d orbit hybridization. Several impurity bands under the conduction band decreased the band gap. The experiment results illustrated that the ferromagnetism had occurred and the absorption spectra had a shift to visible light region in W-doped TiO2 samples. The experiment results are consistent with the calculation ones.