Fluorescence of Gd⁺⁺⁺ in Alkali Halide Crystals

Abstract

Crystals of potassium chloride and potassium bromide containing trivalent gadolinium were prepared from the melt and also by heating the powdered anhydrous mixtures at 600°C. Their fluorescence spectra consisted of four sharp lines around 3114.3 Å and 3115.1 Å respectively. A single mode of charge compensation for the substituted Gd3+ ion with a D3h or C2v symmetry is proposed. Lifetimes of the fluorescence of these doped crystals as well as of pure GdCl3 and GdBrs are of the order of a few msec.