The Electrical Properties of Ice Surfaces

Abstract

AbstractThe surface conductivity of monocrystalline ice was measured as a function of temperature impurity concentration, field-strength, and other variables. At temperature, below about –6°C the surface conductivity was found to follow the Arrhenius equation with an activation energy of 33±2 kcal mol−1 (1.43±0.09 eV). Small amounts of impurities contained within the ice increased the surface conductivity and decreased the actuation energy: for HF-doped ice the activation energy was reduced to 10.0 kcal mol−1 (0.44 eV). Mechanical treatment of the ice surface increased the surface conduction. At temperatures above about —6°C the surface conductivity increased more rapidly with the rise in temperature; this is explained in terms of the appearance and development of a quasi-liquid layer on the ice surface. The electrical behaviour of sublimed ice surfaces was found to vary at a temperature around —9°C. At higher temperature a sharp, instantaneous current increase was observed as evacuation began; this was considered to be caused by the formation of ionic states due to the rapid evaporation of quasi-liquid layers. It was concluded that the temperature above which the ice surface was covered with a quasi-liquid layer lay in the range — 6 to — 9°C.