Dielectric Behavior of NaOH-Doped Ice

Abstract

The dielectric behavior of ice doped with different NaOH concentrations was investigated in the 0° to − 25°C temperature range. In the lower concentration range of 1–4 × 10⁻⁶M NaOH, the conductivity behavior was similar to pure ice. At higher concentrations in the range of 7 × 10⁻⁶M NaOH, significantly higher conductivities were observed with the low‐frequency conductivity being about 5 × 10⁻⁸ (Ω·cm)⁻¹ and exhibiting only a slight temperature dependence. At lower temperatures the static dielectric constant was found to decrease with increasing NaOH concentration. The dielectric relaxation times and corresponding activation energies were about the same as for pure ice. The over‐all behavior is distinctly different from that of HF, HCl, and NH₃‐doped ice. The model postulated to explain the observed results involves the interstitial incorporation of Na bonded to an (OH) site in its normal lattice position. It is postulated that this mode of incorporation causes lattice distortion that increases either the concentration or mobility of the OH‐ionic defects which in turn accounts for the increased conductivity.