Compositional and structural control of tenebrescence

Abstract

The effect of various compositional substitutions on the colour of long-lived F-centres in the sodalite structure has been investigated by the synthesis and characterisation of several phases of the general composition A₈[M′M″O₄]₆[X,S]₂. The visible-region absorption spectrum of the excited state, formed by 256 nm irradiation of the as-synthesised materials, shows a broad absorption whose position correlates with the dimensions of the sodalite cage occupied by the excited electron.