The Behavior of Glass as a Dielectric in Alternating Current Circuits: I. Relation of Power Factor and Dielectric Constant to Conductivity

Power factor, dielectric constant at 1000 cycles and apparent resistivity for six glasses of varying composition, both lead glasses and borosilicates with and without lead, all at 20^∘{}C. The values of the apparent resistivity at 20^∘{}C were found by linear extrapolation, by means of the equation ρ=ek/T, from values of the apparent resistivity calculated from measurements of the resistance of small rods at temperatures ranging from 100^∘{}C to 500^∘{}C. In two cases studied the power factor of strained samples was about 50 percent greater than after annealing. No explanation is offered. For glasses of relatively similar composition both the power factor and the dielectric constant are found to increase with increasing conductivity. The results indicate a close relation between the phenomena of absorption and of ionic conductivity and are shown to be qualitatively in agreement with the theory of Joff\'e that the phenomena of absorption are due to a counter-electromotive force of electrolytic polarization. Possible alternative molecular explanations are suggested.