Effect of ZnO content change on the structure and properties of zinc borophosphate glasses

The glass system x ZnO-10B 2 O 3 -(100 − x )P 2 O 5 was prepared by cooling using the melt-quenching technique in the composition series x from 30 to 60 mol %. The density, thermal expansion coefficient, glass transition temperature, and softening temperature of the glass system were determined. Structural characterization was performed by using a combination of IR and Raman spectroscopy and 11 B/ 31 P solid state NMR spectroscopy data. In particular, variations in the phosphate network structure upon the addition of ZnO were investigated. Data analysis indicated that increasing the ZnO content and decreasing the P 2 O 5 content increased the extent of cross-linking between the phosphate and borate units in the glass network; this was because incorporation of ZnO polyhedra into the structural network of ZnO increased the network dimensionality. These structural changes were confirmed by Raman and IR spectroscopy.