V color centers in electrolytically colored hydroxyl-doped sodium chloride crystals

Hydroxyl-doped sodium chloride crystals were successfully colored electrolytically by using pointed anode and flat cathode at various temperatures and under various electric field strengths. V2 and V3 color centers were produced in the colored crystals. Current-time curves for the electrolytic colorations were given, and activation energy for the V2 and V3 color center migration was determined. Production of the V2 and V3 color centers and formation of current zones for the electrolytic colorations of the hydroxyl-doped sodium chloride crystals are explained.