ALKALI METAL DIFFUSION BARRIER LAYER

摘要

The present invention provides thin metal oxide barrier layers which prevent migration of alkali metal ions from glass substrates which comprise alkali metal into coatings on the glass surface, the properties of which coatings are susceptible to deterioration by the presence of alkali metal such as sodium. The barrier layers of the present invention are effective at unexpectedly thin thicknesses, and have an optimal thickness range which is unexpected, in view of the expectation that a barrier layer will be increasingly effective with increasing thickness.