Influence of Silver on the Sm3+ Luminescence in “Aerosil” Silica Glasses

Abstract

The introduction of silver into the samarium-containing silica glasses prepared by the original sol– gel method leads to the formation of complex optical centers involving samarium ions and simple and/or complex silver ions. These centers are characterized by the effective sensitization of Sm3+ luminescence by Ag+, (Ag2)+, and (Ag+)2 ions according to the exchange mechanism for, at least, Sm3+–Ag+ centers. The formation of Sm–Ag centers is accompanied by an increase in the concentration of nonbridging oxygen ions, which prevent the reduction of silver ions by hydrogen. Silver nanoparticles formed in small amounts upon this reduction are effective quenchers of luminescence from the corresponding excited states of Sm3+ ions.