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RESEARCH PRODUCT

Infrared photoluminescence of preexisting or irradiation-induced interstitial oxygen molecules in glassySiO2and α-quartz

subject

description

A sensitive technique for detecting interstitial ${\mathrm{O}}_{2}$ molecules in ${\mathrm{SiO}}_{2}$ is demonstrated by measuring their infrared $\stackrel{\ensuremath{\rightarrow}}{a}X$ luminescence at 1272.2 nm under a Ti-sapphire laser excitation into the ${\mathrm{O}}_{2}\stackrel{\ensuremath{\rightarrow}}{X}b$ absorption band at 765 nm. Contrary to the case of ${\mathrm{O}}_{2}$ trapped in inert gas matrices, the visible emission of ${\mathrm{O}}_{2}$ corresponding to the direct $\stackrel{\ensuremath{\rightarrow}}{b}X$ transition is not found. Examination of different neutron- and gamma-irradiated glassy ${\mathrm{SiO}}_{2}$ and \ensuremath{\alpha}-quartz samples reveals radiation-induced interstitial oxygen molecules in concentrations between ${10}^{14}$ and ${10}^{16}{\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{e}\mathrm{c}\mathrm{u}\mathrm{l}\mathrm{e}\mathrm{s}/\mathrm{c}\mathrm{m}}^{3}.$ The radiolytic ${\mathrm{O}}_{2}$ molecules in \ensuremath{\alpha}-quartz and glassy ${\mathrm{SiO}}_{2}$ experience different structural environments.