Cathodrochromic Properties of Sodalite

Abstract

The coloration and bleaching behavior of undoped bromide sodalite prepared by solid-state reaction and by various low-temperature hydrothermal reactions is studied. A high coloration sensitivity is obtained; for instance, a charge density of 0.5 μC/cm2 at 10 kV yields a contrast ratio of 2:1. The coloration and optical bleaching behavior is strongly dependent on the preparation method. A relation between bleaching rate and bromide deficit is found. A relation is suggested between residual coloration and the presence of oxygen on bromine sites. The effect of the doping with transition-metal ions on the bleaching behavior is studied. The doping with Fe, Ni, and Cu causes a considerable increase in bleaching rate.