Existence of air-gaps in specimen-electrode contacts and their effect on dielectric relaxation phenomena in KCl and NaCl

Abstract

Dielectric relaxation effects previously reported in KCl and NaCl with and without divalent impurities are reexamined in the 35 Hz–10 mHz range at temperatures between 200° and 700°C. It is demonstrated that, except for those effects which can be unambiguously attributed to the well-known divalent impurity-vacancy interaction, the relaxation at high frequencies and the polarization at low frequencies observed previously can be explained by the presence of air-gaps between the specimen and electrodes. A correct method for measuring the true ionic conductivity of ionic crystals is suggested.