ELECTRICAL-CONDUCTIVITY OF ZINC-BARIUM PHOSPHATE-GLASSES

A series of binary and ternary zinc-barium phosphate glasses was prepared, their densities were measured and their electrical properties were studied. A linear dependence of density with BaO content was observed in barium phosphate glasses while a breaking point in the linearity of the density curves occurs at about 40% ZnO concentration for the zinc-barium phosphate glasses. The d.c. conductivity measurements show that the activation energy is increased when P2O5 is replaced by BaO or ZnO, respectively. In the ternary glasses the activation energy appears to be relatively unaffected when BaO is replaced by ZnO, but at approximately 40% ZnO, there is a rise in the value of activation energy. Such a pronounced change in density and activation energy could be due to the change in the coordination of ZnO in this region. The linear log-sigma-1/T curves and also the value of sigma-0 suggest that the conduction mechanism in these glasses is similar to those in many other oxide glasses that have been investigated.