Electric Potential of a Rubbed Ice Surface

Abstract

The electric potential of an ice surface rubbed by a single crystal ice piece was investigated both theoretically and experimentally. The negative electric potential on the rubbed ice surface increased with increasing number of dislocations on the ice surface. In order to explain this negative electric potential of a rubbed ice surface, it was assumed that negatively electrified dislocations and positively electrified D-defects were produced in pairs by rubbing. In the steady state, a potential difference is set up at the surface such that the surface becomes negative because of the much greater mobility of D-defects than dislocation. On the bases of some theoretical arguments it is predicted that the surface potential is ?58 mV when the dislocation density at the ice surface is one order of magnitude larger than that in the interior of the ice. It is thought that these phenomena are of basic importance in the generation of positive electric charge of graupel pellets and hail at colder temperatures.