On the V-centers in Alkali Iodide Crystals

The properties of V-center were investigated in the alkali iodide crystals (KI and NaI) containing excess iodine, In KI, the absorption spectrum was similar to that obtained by Mollwo, but for details, there were some difference. It was pointed out that the V-band in KI can be understood as superposition of three bell-shaped bands I , II , and III . Of these, both band I and II can be safely assigned to V 2 -band. As for band III , however, explanation is not possible at present though it seems to have fairly close relation to the other two bands. Some proposals were made in regard to the mechanism of the coloring with the pointed electrode and the explanation of the doublet structure of V 2 -band in KI.