Characterazation of various glasses in the binary PbO-GeO sub 2 and Bi sub 2 O sub 3-GeO sub 2 systems.

Various physical properties including infrared and Raman spectra were measured for series of glass compositions in the binary PbO-GeO sub 2 and Bi sub 2 0 sub 3-Ge0 sub 2 systems. Regions of constant glass transition temperature (T sub g) were noted at higher germania compositions for both binary glass series, clearly indicating the presence of amorphous phase separation. Changes in vibrational spectra with changes in glass composition are discussed in terms of structural changes, including change in coordination for germanium and/or changes in the bridged oxygen/non-bridged oxygen ratio. Changes in other physical properties such as density and molar volume with changes in glass composition are also discussed in terms of these changes.