On the influence of lead and cadmium fluoride content on thermal, optical and structural properties of oxyfluoride glass

Highlights: • Novel oxyfluoride glass compositions. • Role of PbF₂ and CdF₂ in oxyfluoride network. • Increase in stability with increase in CdF₂ content. - Abstract: This study reveals the effect of PbF₂ and CdF₂ addition on the aluminosilicate oxyfluoride glass network over a wide compositional range. The structure of glasses in SiO₂–Al₂O₃–PbF₂ and SiO₂–Al₂O₃–PbF₂–CdF₂ system matrices was studied by using DTA, XRD, UV–VIS, density, Raman and FTIR spectroscopy. The observed shifts of absorption edge due to band gap variations with heavy metal fluoride (HMF) addition are compared with theoretical model of optical basicity and physical parameters derived from density. The variation in T_g, and stability factor are supported by Raman and FTIR results which show formation of NBOs and other super structural units with addition of HMF in the aluminosilicate network