The thermostimulated luminescence of radiation defects in KCl, KBr and KI crystals at elastic and plastic deformation

Abstract

The efficiency of radiation defects formation in alkali halide crystals (AHC) was studied by the method of absorption spectroscopy. However, it is not possible to study the deformation-stimulated processes in detail by the absorption spectrum of radiation defects due to the limited sensitivity compared with luminescent spectroscopy. In this regard, thermally stimulated luminescence (TSL) of radiation defects at elastic and plastic deformation was applied in AHC. In the absence of deformation, the dominant peaks in TSL are -centers. After elastic deformation, low temperature peaks of TSL corresponding to F′-, VK- and VF-centers became dominant. After plastic deformation, the peaks of TSL corresponding to -centers became dominant. The elastic deformation contributes to the increase in concentration of low-temperature F′-, VK- and VF-centers, and the plastic one contributes to that of high temperature -centers (peaks of TSL in KCl at 360K, in KBr at 365K, in KI at 340K), composed by divacancies created by plastic deformation. At elastic deformation, unrelaxed interstitial halogen atoms are converted into VK- and VF-centers, and due to this fact the long-range interaction is absent, the result of which are the -centers.