Investigations of the thermal, structural, and Near-IR emission properties of Ag containing fluorophosphate glasses and their crystallization process

In this work, the impact of Ag₂O on the thermal, structural, and Near-IR luminescence of Er³⁺ doped calcium-fluorophosphate glasses is investigated. The amount of silver oxide in the glass significantly impacts its thermal stability and crystallization process. The increase in the thermal stability of the glasses might be attributed to the depolymerization of the metaphosphate network evidenced using FTIR and Raman spectroscopies. The precipitation of Ag nanoparticles within the glass network, induced by a thermal treatment, has been confirmed by the appearance of a clear visible broad absorption band centered at about 450 nm in the glasses after heat treatment. Such species induce a significant enhancement in the Er³⁺ IR emission. Transparent glass-ceramics have also been processed by thermally treating the glasses. The XRD analyses have revealed that the addition of Ag₂O in the glass promotes the precipitation of new crystalline phases at the expense of CaF₂ crystals. The presence of such nanostructures in the glass network induces some modifications in the distribution of Er ion sites.