Dielectric constant and depolarization current of ice

Dielectric properties of ice are governed by proton hopping, which is proton migration among proton vacancies in the crystal structure. Proton hopping changes its activity with temperature and pressure. We observed the capacitance of ice at 253K and 77K. The capacitance at 77K was much lower than that at 253K. This result shows that behavior of proton in ice at 253K is different from that at 77K. Proton in ice can migrate between proton vacancies at 253K, but cannot at 77K because of low thermal energy. On the other hand, ice XI, one of crystal structure of ice, has ferroelectricity because being polarized by distribution of proton. Crystal structure, therefore proton distribution is another factor to govern dielectric properties of ice. In this paper, we focused on temperature dependent proton migration in ice and we tried to control proton distribution by DC voltage application to obtain the polarized ice. DC voltage was applied to ice during cooling process from 253K to 77K aiming at polarization in ice. Then we measured depolarization current of ice. We confirmed that polarization takes place in ice.