The diffusion coefficients in vitreous silica coatings, which had been prepared by using the sol-gel method, were deduced from Auger depth profiles and Raman measurements. The coatings were deposited onto Cu substrates, and were isothermally treated at various temperatures in air. The O which diffused through the glass coating formed an oxide layer at the Cu/SiO2 interface. The treatment, at a given temperature, was continued until the minimum thickness of the copper oxide layer which formed at the Cu/SiO2 interface was detectable by using Raman spectroscopy. This oxide layer thickness was determined by means of Auger depth-profiling measurements. It was found that the room-temperature data could be described by:

D (cm2/s) = 2.2 x 10-15 exp[-0.5(eV)/kT]

Oxygen Diffusion in Silica Glass Prepared by the Sol-Gel Method. F.J.García-Rodríguez, F.Pérez-Robles, A.Manzano-Ramírez, Y.V.Vorobiev, J.González-Hernández: Solid State Communications, 1999, 111[12], 717-21