Electronic Structure and Defect States of Transition Metal Doped Rutile TiO2
The electronic structure and defect states of 6.25% transition metal (TM = Fe and Co) doped rutile titanium dioxide were investigated by ab initio ultrasoft pseudopotential plane wave method based on density functional theory. When a Fe or Co atom was substituted for a Ti site of TiO2 lattice, additional unoccupied 3d-states of TM appeared as defect states in band-gap and occupied 3d-states represented metallic behavior (half-filled states).It was found that two occupied defect states and one half-filled defect state were the 3d-states of TM from the calculation of band decomposed charge density. The higher unoccupied states were hybridized with unoccupied oxygen 2p-states and located at the middle of band-gap.
Byung Tae Ahn, Hyeongtag Jeon, Bo Young Hur, Kibae Kim and Jong Wan Park
Y. S. Kim et al., "Electronic Structure and Defect States of Transition Metal Doped Rutile TiO2", Solid State Phenomena, Vols. 124-126, pp. 787-790, 2007