The UV–VIS optical absorption spectra of oxidized and reduced rutile single crystals were measured by means of spectrophotometer and two absorption peaks around 430 and 730nm were found. These spectral data were analyzed by using the crystal field theory. Based on these studies, it was suggested that the reduced crystal contained the defect center [Ti3+–Ov], with the O vacancy (Ov) on one of the nearest neighbor sites of the central Ti3+ ion.

Defects in Reduced Rutile Single Crystal. T.C.Lu, S.Y.Wu, L.B.Lin, W.C.Zheng: Physica B, 2001, 304[1-4], 147-51