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

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.