Physical properties of PbO-ZnO-P2O5 glasses -: I.: Infrared and Raman spectra

Phosphate glasses of composition x PbO - 10 ZnO - (90-x) P2O5, 30 less than or equal to x(mol. %) less than or equal to 55 (series A); 50 PbO -x ZnO - (50-x) P2O5, 0 less than or equal to x(mol %) less than or equal to 20 (series B); and x PbO (60 - x) ZnO - 40 P2O5, 0 less than or equal to x(mol %) less than or equal to 60 (series C), were investigated. Depending mainly on the PbO content in glasses, the density varies in the range 3.2 to 5.5 [g/cm(3)], the glass-transition temperature lies in the region 270 - 394 degreesC. Both the Raman and infrared spectroscopy were used to study the considerable structural changes in the phosphate network induced by incorporation of PbO and ZnO into a glass network. Depending on the actual system, PbO behaves as a network modifier and/or network former, especially for higher content of PbO. ZnO in most of cases seems to prefer to interact with PO3-end groups. In the C-series of glasses the local minimum in the glass-transition temperature T-g(PbO) dependence, we speculate, could reflect some tendency of the system to a local nano-phase separation.