Oxygen diffusion in silica glass prepared by the sol-gel method

The oxygen diffusion constants for SiO2 coatings, prepared by the sol-gel m ethod, were determined from Auger depth profile and Raman measurements. To do that, the coatings were deposited on copper substrates, and isothermally treated at various temperatures in air. The oxygen diffusion through the g lass coating formed an oxide layer at the copper/SiO2 interface. The treatm ent times, at a given temperature were maintained until the minimum thickne ss of the copper oxide layer formed at the copper/SiO2 interface was detect able by Raman spectroscopy. This oxide layer thickness was determined from Auger depth profile measurements. The room temperature values for the diffu sion constant and the activation energy were, 2.2 x 10(-15) cm(2)/s and 0.5 eV, respectively. (C) 1999 Published by Elsevier Science Ltd. All rights r eserved.