Oxygen species in SiO 2: a first-principles investigation

Abstract

Using a density functional approach, we determine the relative stability of various oxygen species in α-quartz. We considered interstitial species in the form of atomic and molecular oxygen, as well as network species, such as peroxyl and ozonyl linkages. The interstitial molecular oxygen species is found to be the most stable one. The ozonyl linkage lies higher in energy by 1.0 eV. Dissociation of the interstitial O 2 molecule into two peroxyl linkages or into two interstitial oxygen species occurs at even higher energies (1.6 and 3.2 eV, respectively). These results favor a long-range diffusion mechanism based on the interstitial O 2 molecule.