Semi-quantitative analysis for FTIR spectra of Al2O3-PbO-B2O3-SiO2 glasses

► IR spectra of Al2O3-PbO-B2O3-SiO2 glasses was measured and analyzed. ► Analysis reveals a change in the role of PbO from modifier to glass former at 12 mol.% Al2O3. ► With increasing Al2O3 the crosslinking of the glass network decreases. ► The silicate network tends to be distinguished from the reminder of the whole glass network.