Influence of compressive load and heat treatment on deformation luminescence of KCl:Eu2+ single crystals exposed to X-ray

Abstract

When KCl:Eu2+ single crystals were exposed to X-ray and were plastically deformed by compression at 50 µm min−1, the peak appears around 330 K on the thermoluminescence (TL) glow curve under the influence of the compressive load below 200 N. The peak is termed 330 K peak here. Its intensity becomes slightly large with the compressive load and also depends on the quenching temperature above about 473 K for the preparation of sample. Furthermore, the 330 K peak disappears on the TL glow curve by the heat treatment: annealing at 953 K for 16 h, followed by gradually cooling to room temperature within 24 h. The variations in the 330 K peak height are related to the density of dislocations in the sample. On the absorption spectrum for the crystal, the peak height at the wavelength of 560 nm decreases by the heat treatment. This result is supposed to be caused by the phenomenon that dislocation density is reduced and some colour centres on the 330 K peak etc. are removed in the annealing process of the crystal.