Clustering of silver atoms in hydrogenated silver-sodium exchanged glasses

The diffusional growth regime of silver clusters in hydrogenated silver-sodium exchanged glasses has been numerically analysed. The diffusion coefficients of the three elements that contribute to silver cluster formation, namely H, Ag+, and Ag-0, have been established. The activation energy of the reactant Ag-0 diffusion coefficient is consistent in the three analysed different experimental results: Ag loss through evaporation, near-surface Ag accumulation, and optical absorption density. The calculated Ag-0 diffusion coefficient accounts for the threshold time necessary to obtain a cluster size to give rise to a detectable absorption.