Electrode Polarization of Glasses

The low-frequency dielectric characteristics of soda-lime and sodium-silicate glasses were determined as a function of temperature, electrode materials, surface condition, and specimen thickness. The resulting large dielectric constant (often called electrode polarization) was dependent on surface condition of the glass specimen when evaporated metal electrodes were used and insensitive to surface condition when paste electrodes were used. The space charge mechanism was suggested as an explanation for these phenomena. The dependence of the dielectric constant on frequency and specimen thickness agrees with predictions of theory