Effect of CuO-addition on the Dielectric Parameters of Sodium Zinc Phosphate Glasses

The dielectric properties of sodium zinc phosphate glasses doped with copper oxide have been investigated over a frequency range of 1.05-100 kHz in a vacuum medium (10(-5) torr). Some dielectric parameters, such as dielectric constant epsilon', dielectric loss epsilon '', dielectric loss tangent (tan delta) and AC conductivity, have been estimated. It is observed that the dielectric constant is strongly dependent on the CuO concentration in the investigated phosphate glasses. The AC conductivity measurements show that these phosphate glasses are good electronic conductors. With the aid of transmission spectra of these glasses, the absorption coefficient and the optical direct bandgap are estimated. The optical bandgap is found to decrease with increasing CuO content indicating the formation of non-bridging oxygens.