Copper ions influence on lead–phosphate glass network

The structure of xCuO·(1 − x)[2P2O5·PbO] glass system with 0 ⩽ x ⩽ 50 mol% was investigated by Raman spectroscopy. The characteristic bands of these glasses were identified and analyzed by increasing CuO content. A deconvolution of each Raman spectrum was made in order to make a better identification and assignment of all bands which appear in these spectra Thus, by determining the number of all independent components it was possible to carry out a quantitative analysis of the spectra and also to find the concentration distribution of these components across the investigated glass system. By adding CuO, the symmetric vibration of POP bond in Q2 groups shifts to higher frequencies due to the depolymerization of long phosphate chains and the bands attributed to (PO2)asym. stretching and (PO)sym. stretching vibrations shift to lower frequencies due to the linking of PO bond to cooper ions. The UV–visible optical absorption results suggest that Cu ions act as a modifier in the studied glasses and may have a possible former role over 20 mol%. Beside this, cooper can be considered as a color center in this glass system.