Measurements of the Electrical Properties of Ice Ih Single Crystals by Admittance and Thermally Stimulated Depolarization Techniques

• Published in: Journal of Glaciology
• Main Authors: Loria, Arturo, Mazzega, Ezio, Pennino, Umberto del, Andreotti, Giovanni
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1978
• Subjects: Earth-Surface Processes; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000033426; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000033426

Abstract Ice Ih single crystals were investigated by complex admittance and thermally stimulated depolarization (TSD) techniques, in the relaxation-time ranges 10 –5 –10 s and 10–10 4 s respectively. The relaxation spectrum was resolved and three components of it were studied. Second-order kinetics had to be assumed for two of the TSD spectra to obtain Arrhenius-type relaxation times. The “Debye spectrum” had an activation energy for the relaxation time of 0.64 eV at the high temperatures and its dielectric strength revealed a possible defect cross-over at T c = 190 K. Far below this temperature the activation energy was 0.38 eV, that is about half of that necessary for a pair of ion defects to form. In comparison with the results of other authors, a lower concentration of ionic defects, or possibly of Bjerrum–ion aggregates, was deduced to occur in our crystals. Inert-gas host molecules were proposed as a possible origin of the two other spectra, having relaxation times shorter than the “Debye spectrum” and energies of 0.33 eV and 0.37 eV. Moreover the 0.33 eV spectrum, whose dielectric strength appears at a temperature below T c , might alternatively be related to the cross-over of the “Debye spectrum”.