A New Radiochemical Method for Determining the Oscillator Strength of F Centres in Alkali Halides

Abstract

AbstractA new radiochemical method for determining the concentration of F centres in X‐ or γ‐ray coloured crystals of alkali halides is described. The method is based on the fact that crystals containing F centres upon dissolution in water give rise to the formation of an equal amount of hydrated electrons. Hydrated electrons are able to reduce [Co(NH3)6]3+complex ions to Co2+; thus, by dissolving crystals containing F centres in a water solution of [Co(NH3)6]3+ions, the amount of formed Co2+ions is related to the concentration of F centres in the crystals. The method was applied to the determination of F centre concentration in NaCl, KC1, and KBr crystals coloured by50Co γ‐ray irradiation. The use of these concentrations in the Smakula absorption formula enables to calculate the optical oscillator strength / of F centres. The / values obtained are as follows: ƒNaCl = 0.64 ± 0.02; ƒKCl = 0.68 ± 0.02; /KBr = 0.72 ± 0.02. These results are compared with those already reported in literature.