Impurity-induced thermally stimulated luminescence of KMgF3:Ce3+ crystals

The thermally stimulated luminescence (TSL) of KMgF3 doped with Ce3+ has been measured using a high-sensitivity TSL spectrometer that measures the emitted intensity as a function of both temperature and wavelength. TSL peaks have been detected at 80, 170°C and in the regions of 300–400°C (heating rate 1°C/s). The TSL emissions are at 270 and 360 nm, the latter emission showing a strong dependence on Ce3+ concentration. The correlation of these emissions with recently published photoluminescence data and the behaviour of the TSL peaks as a function of Ce3+ concentration allows an interpretation of the responsible defects, in terms of two types of substitutional replacement of K+ ions with Ce3+ impurities.