We have proved that silver or copper staining processes at higher
temperature than the glass vitreous temperature lead to the nanoparticles
formation which is responsible of yellow and red coloration effect. We
have also shown by SEM measurement that this staining process is in
fact an ionic exchange process with one silver or copper ion exchanged
for a sodium onewith a diffusion profile limited by aggregation phenomenon.
We have pointed out by UV/Visible Measurements that these
nanoparticles exhibit a significant SPR in the visible region. This SPR is
averaged by an effective medium consideration obtained with an appropriate
Maxwell-Garnett model. The TEM and XRD measurements have
led to an estimate of the typical radius of the NPs and the maximal fill
factor. By infrared measurement we have suggested a coexistence of
these NPs with metallic ions. A core-shell system has to be considered
due to a possible metal oxidizing of the NPs surface. In a future work
the effective dielectric function could be introduced in a two-layer optical
model [33].Silver or copper species (complexesorneutralizedatoms) can also influence the visible response and can lead to luminescence effect
[34,35].