ELECTRIC PROPERTIES OF PBO-BI2O3-GA2O3 GLASSES

In this work the dielectric constant and dielectric loss of PbO-Bi2O3-Ga2O3 glasses were determined on the basis of capacitance and loss tangent measurements of glass capacitors. The electric conductivity was examined by the impedance spectroscopy method. The glasses exhibit low dielectric losses and high dielectric constants (29-45) increasing with Bi2O3 content. The electric conductivity of all the glasses studied was of the order of 10(-11) S cm-1 at room temperature and 10(-9)-10(-6) S cm-1 at 300-degrees-C, depending on the composition--it rose with increasing content of heavy metal oxides. The conduction may be of a mixed ionic-electronic nature; determination of the current carrier type and the conduction mechanism needs further research.