The Permittivity and Attenuation in Polycrystalline and Single-Crystal Ice Ih at 35 and 60 MHz

The relative permittivity ∊’ and attenuation α in laboratory-grown, polycrystalline and single-crystal ice Ih are reported at 35 and 60 MHz in the temperature range —25°C to — 0.2 ° C. The ∊’ and α at 35 MHz and — 1° C are 3.208±0.010 and 6.2±0.1 dB/100 m, respectively. From a comparison between the respective ∊’ and α of the polycrystalline and single-crystal ice measured perpendicular to the c -axis, it is concluded that any anisotropy of polarization at these frequencies is so small as to be undetectable. Amongst several factors that may contribute to anisotropy in ice, electronic polarization contributes 0.0037 to the difference between the relative permittivity measured parallel and perpendicular to the c -axis at — 1° C and at frequencies less than 500 THz. Experiments have shown that the plastic deformation resulting from a uniaxial compressive stress of up to 100 bar does not influence the ∊’ and α of ice at 35 and 60 MHz.