Determination of the Optical Constants of the Photostimulable BaFCl: Eu2+and KCl:Eu2+Crystals

A new method to determine the concentration of the defect centers in photostimurable luminescent materials is demonstrated. The method is representatively applied to BaFCl:Eu2+and KCl:Eu2+single crystals, which exhibt the photostimulable luminescence. Thereby the values of the oscillator strength, f, are calculated utilizing the results of the defect center concentrations as well as the measured refractive indices and the corresponding absorption bands by using the Smakula's formula. The values obtained are f=0.80 for the F(Cl-) centers in BaFCl:Eu2+and f=0.60 for the F centers in KCl:Eu2+.