Self-diffusivity of network oxygen in vitreous SiO2

Secondary ion mass spectrometry was used to profile the interdiffusion of network oxygen in a Si 16O2-Si 18O2 thin-film structure. The diffusivity from 1200 to 1400 °C can be described by D=2.6 cm2 s−1 exp (−4.7 eV/kT). The diffusivity values are lower, but with a higher activation energy, than those previously reported in the literature and approach the intrinsic diffusivity uncomplicated by extrinsic gas phase isotope exchange reactions.