DIFFUSION OF OXYGEN IN SILICA GLASS

Diffusion of oxygen in silica glass is modeled to result from the diff usion of molecular oxygen or water into the glass and isotopic exchang e with the oxygen in the silicon-oxygen network. Comparison with exper imental data shows good agreement with the model. In many experiments, low water concentrations contribute to the diffusion profiles. It is concluded that network diffusion is too slow and surface exchange too rapid to contribute to the experimental diffusion profiles of oxygen i sotopes.