An infra-red absorption spectroscopic study was made of N-O complexes in samples which had been implanted with various combinations of O and N isotopes, as well as in O-rich samples which had been doped with N during growth. Local vibrational modes at 805, 999 and 1030/cm (14N, 16O) were shown to belong to a defect which consisted of a N-pair which interacted with an O interstitial. A recently proposed model for this NNO defect was also investigated by means of  ab initio  cluster calculations, and it was found to account for the dynamic properties of the defect. A mode at about 730/cm, which was predicted by the calculations, gave further support to the model.

F.B.Rasmussen, S.Oberg, R.Jones, C.Ewels, J.Goss, J.Miro, P.Deák: Materials Science Forum, 1995, 196-201, 791-6