Czochralski-type samples were irradiated with fast neutrons at room temperature, and the identity of the defects which were produced was investigated by using infra-red spectroscopy. Two localized vibrational modes, at 914 and 1000/cm, were considered to reflect intermediate defect stages between VO and VO2 complexes. They were suggested to arise from a [VO+Oi] defect in which an interstitial O atom was trapped near to a VO pair. Another 2 peaks, at 1032 and 1043/cm, were attributed to the VO4 defect.

C.A.Londos, G.I.Georgiou, L.G.Fytros, K.Papastergiou: Physical Review B, 1994, 50[16], 11531-4