Selfhyphen;diffusivity of network oxygen in vitreous SiO2

摘要

Secondary ion mass spectrometry was used to profile the interdiffusion of network oxygen in a Sithinsp;16O2hyphen;Sithinsp;18O2thinhyphen;film structure. The diffusivity from 1200 to 1400thinsp;deg;C can be described byD=2.6 cm2thinsp;sminus;1thinsp;exp (minus;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.