Microwave dielectric properties of the ice core from Dome Fuji, Antarctica

Measurements of relative complex dielectric permittivities, epsilon* = epsilon' - i epsilon ", of ice core recovered from Dome Fuji, Antarctica were carried out at 33 GHz in the temperature range 210-260 K. The open resonator method was used for precise measurement of temperature dependence of the real part, epsilon', and imaginary part, epsilon ", of dielectric permittivities. The following results were obtained: small dielectric anisotropy, Delta epsilon' = \epsilon'(parallel to c)-epsilon'(perpendicular to c)\, was observed (Delta epsilon' = 0.0104 +/- 0.0004) and was independent of temperature. The increase rate of epsilon' with increase of temperature changed at around 238 K. The increase rate, d epsilon'/dT, above 238 K was three times larger than that below 238 K and the values were 0.0011 and 0.0003 above and below 238 K, respectively. Also, Raman spectra measurements were carried out and the result showed that the increase rate of frequency of translational lattice vibrations with increase of temperature changed at around 238 K.