The dielectric properties of H2O and D2O ice Ih at MHz frequencies

Abstract

The permittivity and loss of ice Ih have been measured between 0.5–100 MHz in the temperature range 243–273 °K. An analysis of the temperature dependence of the limiting high‐frequency permittivity ε_∞ shows that the known decrease in frequency of lattice vibrations with increasing temperature predicts values of ε_∞ much higher than those measured. It is suggested that the absorptivity at the infrared frequencies should decrease with increasing temperature. Deuteration of ice decreases its ε_∞ by ∼3%. This is interpreted to indicate less absorption of infrared frequencies in D₂O than in H₂O ice. Ice shows a secondary relaxation centered in the MHz frequency range with an amplitude of 0.08 at 268 °K. The ε_∞ of single crystal ice, measured perpendicular to the c axis, is indistinguishable from that of polycrystalline ice, thus indicating little anisotropy of the high‐frequency polarization.