Infrared photoluminescence of preexisting or irradiation-induced interstitial oxygen molecules in glassy SiO2 and α-quartz

A sensitive technique for detecting interstitial O-2 molecules in SiO2 is demonstrated by measuring their infrared a-->X luminescence at 1272.2 nm under a Ti-sapphire laser excitation into the O2X-->b absorption band at 765 nm. Contrary to the case of O-2 trapped in inert gas matrices, the visible emission of O-2 corresponding to the direct b-->X transition is not found. Examination of different neutron- and gamma-irradiated glassy SiO2 and alpha-quartz samples reveals radiation-induced interstitial oxygen molecules in concentrations between 10(14) and 10(16) molecules/cm(3). The radiolytic O-2 molecules in alpha-quartz and glassy SiO2 experience different structural environments. [S0163-1829(98)00645-6].