On the V-centers in KBr Crystals

Abstract

The natures of V bands in the additively colored crystals of KBr has been investigated. Mollwo’s results were confirmed and extended. A new technique of additive coloring was devised to produce a high concentration of V centers in the crystal of KBr. By using this method, the degree of coloration could be increased by about ten times of that reported by Mollwo. Besides the well-known V₂ and V₃ bands, another band of V-type was observed below 210 mμ.
It was found to be possible to color electrolytically the crystal of KBr revealing the same absorption spectrum as that of additively colored crystals. Evidently, this confirms that these absorption bands are produced as the result of the combination of positive holes and positive ion vacancies. Discussions were made in comparison with the results obtained for KBr colored with X-rays.