A sensitive technique for detecting interstitial O2 molecules was demonstrated by measuring their infra-red a → X luminescence at 1272.2nm under Ti-sapphire laser excitation into the O2X → b absorption band at 765nm. Contrary to the case of O2 trapped in inert-gas matrices, the visible emission of O2 corresponding to the direct b → X transition was not found. Examination of various neutron- and γ-irradiated glassy SiO2 and a-quartz samples revealed radiation-induced interstitial O molecules in concentrations of between 1014 and 1016molecules/cm3. The radiolytic O2 molecules in a-quartz and glassy SiO2 experienced differing structural environments.

Infra-Red Photoluminescence of Pre-Existing or Irradiation-Induced Interstitial Oxygen Molecules in Glassy SiO2 and a-Quartz. L.Skuja, B.Güttler, D.Schiel, A.R.Silin: Physical Review B, 1998, 58[21], 14296-304