Sites Distribution And Properties Of Al2O3-Pbo-B2O3 Glasses

Infrared spectra, density and electric conduction have been investigated for xAl2O3.(50-x)PbO.50B2O3 glasses. The fraction of four-coordinated boron atoms has been calculated from the area under the component bands of the IR spectra. It decreases with increasing Al2O3 content which assumes association of modifier PbO with AlO4 tetrahedra at the expense of BO4 ones. Analysis of density data suggests that Al2O3 enters the structure in a single form as network forming AlO4 tetrahedra. Both the electric conductivity and activation energy decrease with increasing Al2O3 content.