Study Of Lithium-Lead Phosphate And Borophosphate Glasses

Lithium-lead phosphate and borophosphate glasses were studied in compositional series of xLi2-(50-x)PbO-50P2O5, xLi2O-(50-x)PbO-40P2O5 and xLi2O-(50-x)PbO-30P2O5. All glasses crystallize on heating within the range of 400-610C. Their glass transition temperature decreases with increasing Li2O content in the region of x = 0-30 mol% Li2O and then slowly increases in all series of glass reflecting thus changes in the bond strength of the glass structural network. Density, molar volume and chemical durability of the glasses decrease with increasing Li2O content. The 31P MAS NMR and Raman spectra show that all glass series with the replacement of PbO by Li2 the ratio of Q2/Q1 units, present in the structure, slightly increase.