(A), which is proportional to the concentration of this structural group [21]. The characteristic parameters of each band of the FTIR spectra are given in Table 2. Fig. 3 illustrated the curve fitting spectra of the glasses 0 Bi2O3 − (40 B2O3–32 CKD–3 BaO) − 25 PbO, as an example. The values of the FTIR of the base glass agreed well with that reported for borate-based glasses [21,1].