18O-labeled interstitial oxygen molecules as probes to study reactions involving oxygen-related species in amorphous SiO2

Isotope labeling has been widely used to study reactions involving oxygen species in amorphous SiO2 (a-SiO2). This article briefly describes recent progress in 18O labeling techniques to study reactions involving interstitial oxygen molecules (O2), which is one of the most important excess oxygen species in a-SiO2. The primary focus will be on the combination of the 18O labeling with photoluminescence spectroscopy, which enables sensitive and selective detection of interstitial O2. Advantages of this method and results of evaluation of oxygen exchange between interstitial O2 and the Si―O network of a-SiO2 will be presented.