Electrical properties of lead borosilicate glasses

DC electrical conductivity, σ, density, D, and molar volume, Vm, of xSiO2-(50−x)PbO-50B2O3 glasses have been studied. The results suggested that the modifier part of PbO is associated with the borate network as well as the silicate one. The activation energy for conduction, W, was found to depend predominantly on the mobility of charge carriers while the pre-exponential factor of the DC conductivity, σ0, depends predominantly on the charge carrier concentration. Each of ln σ0, W and the conductivity at certain temperature showed drastic changes at 5 mol% SiO2. The density of these glasses has been decreased continuously upon increasing SiO2 at the expense of PbO content, although the molar volume becomes nearly constant up to 10 mol% SiO2. The mobility of Pb2+ ions in silicate is larger than that in borate network.