New oxyfluoroniobate glasses in CdNbOF−BaF−ErF systems

New glasses have been synthesized in the CdNbOF−BaF−xErF (x = 0–5.0 mol. %) system. The glasses are two-phase. The ratio of amorphous phases, depending on the erbium trifluoride content in the glass, affects the thermal, crystallization, structural and optical characteristics of the glasses. When the ErF content in the glass is 3 mol. %, rearrangements in the glass structure occur, leading to an increase in the connectivity of oxyfluoroniobate networks. Glasses in the CdNbOF−BaF−ErF system are characterized by green luminescence of Er, corresponding to the transitions: S → I (544 nm), H → I (551 nm). The luminescence intensity increases with an increase in the ErF content to 2 mol. %. A further increase in the content of erbium trifluoride in the glass composition leads to a gradual decrease in the luminescence intensity, caused by concentration quenching and changes in the structure and phase composition at given dopant concentrations.