Electrolytic coloration and spectral properties of hydroxyl-doped potassium chloride single crystals

Hydroxyl-doped potassium chloride single crystals are colored electrolytically at various temperatures and voltages using a pointed cathode and a flat anode. Characteristic OH− spectral band is observed in the absorption spectrum of uncolored single crystal. Characteristic O−, OH−, U, V2, V3, O2−–Va+, F, R2 and M spectral bands are observed simultaneously in absorption spectra of colored single crystals. Current–time curve for electrolytic coloration of hydroxyl-doped potassium chloride single crystal and its relationship with electrolytic coloration process are given. Production and conversion of color centers are explained.