Formation of additive V centers in disks prepared from powdered alkali halides

The observation of V bands in the absorption spectra of pressed disks prepared from KBr, KCl, and NaCl are recorded. The V centers were produced by two methods: (a) by heating a powdered mixture of the alkali halide and cupric chloride, (b) by heating the alkali halide powder previously soaked in halogen vapor at room temperature. In both cases the powders were heated to about 100°C under reduced pressure; the presence of air interfered with the reaction.