Electrolytic coloration and spectral properties of OH−-doped KBr polycrystals

OH−-doped KBr polycrystals were colored electrolytically by using a pointed cathode and a flat anode. Characteristic O−, OH−, U, Cu+ and O2-–Va+ absorption peaks were observed in resolved absorption spectrum of uncolored polycrystals. Herein the position of the O2-–Va+ absorption peak at room temperature was determined by using a Mollwo–Ivey plot. Characteristic V2, V3, Cu+, O2-–Va+,I2-, I2 and F spectral bands were observed in Kubelka–Munk functions of colored polycrystals. Current–time curve for electrolytic coloration of an OH−-doped KBr polycrystal and its relationship with electrolytic coloration process were given. Formation and conversion of color centers were explained.