Reactions and diffusion of atomic and molecular oxygen in the SiO2 network

To address the reactions and diffusion of atomic and molecular oxygen in SiO2, the modification of the SiO2 network on exposure to an atomic or molecular oxygen atmosphere is investigated by measuring the x-ray-diffraction profile of the residual order peak emanating from the oxide. Analyses of the peak intensity and its fringe pattern provide experimental evidence for the recent theoretical predictions, indicating that atomic oxygen is incorporated into the SiO2 network near the surface and diffuses toward the interface along with modifying it even at a low temperature of 400°C, whereas molecular oxygen diffuses without reacting with the bulk SiO2 even at a temperature of 850°C that is sufficiently high for oxidation reaction at the interface.