Charge Separation by Collision of Ice Particles on Metals: Electronic Surface States

Abstract

Abstract The charge separation of ice particles colliding with metals was investigated in a wind tunnel (air speed 10 m/s) at a temperature of —45°C for different metals as a function of an applied external electric field. The ice particles (to μm radius) collided with the metal target at a rate of 105 per second. The charge separation produced by different metals can be explained by the contact potential difference between the metal and the ice introducing electronic surface states on the ice. A lower limit for their density (1016m–2) is found. The influence of the electric field is explained by an interaction between Bjerrum defects and the electrons of the metal, the transfer probability depending on the charge in the surface states.