Raman and infrared study of (PbO)x(P₂O₅)(1−x) glasses

The structure of binary (PbO) x (P 2 O 5 ) (1− x ) glasses was investigated using Raman scattering and infrared spectroscopy, over the compositional range x = 0.5–0.68. The distribution of the phosphate groups (PO 2 ) − , (PO 3 ) 2− , (P 2 O 7 ) 4− and (PO 4 ) 3− , determined from the simulation of Raman spectra in the 800–1500 cm −1 wavenumber range, indicates a significant disproportionation reaction near the pyrophosphate composition and shows a phosphorus connectivity scheme in the glass structure in agreement with 31 P magic angle spinning NMR results. The low‐wavenumber Raman spectra of glasses are discussed in the light of the spectra of crystals. The mode laying in the far‐infrared region and due to lead–oxygen vibrations exhibits a composition‐dependent wavenumber that correlates with bulk glass properties such as glass transition temperature.