Iodide Impurity Absorption in Potassium and Sodium Bromides

Abstract

Optical absorption bands due to a dilute iodide ion impurity in potassium bromide and sodium bromide are reported. Experimental data show, and semiquantitative theoretical arguments are given, which indicate that the displacement of the iodide impurity absorption from the absorption of the bromide lattice is approximately equal to the difference in the electron effinities of iodine and bromine.