To address the reactions and diffusion of atomic and molecular O in SiO2, the modification of the SiO2 network on exposure to an atomic or molecular O atmosphere was 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 provided experimental evidence for the recent theoretical predictions, indicating that atomic O was incorporated into the SiO2 network near the surface and diffused toward the interface along with modifying it even at a low temperature of 400C, whereas molecular O diffused without reacting with the bulk SiO2 even at a temperature of 850C that was sufficiently high for oxidation reaction at the interface.

Reactions and Diffusion of Atomic and Molecular Oxygen in the SiO2 Network. K.Tatsumura, T.Shimura, E.Mishima, K.Kawamura, D.Yamasaki, H.Yamamoto, T.Watanabe, M.Umeno, I.Ohdomari: Physical Review B, 2005, 72[4], 045205 (5pp)