Thermoluminescence and thermally stimulated conductivity of heavily coloured NaF and NaF:Mg2+ crystals

The authors have reported the experimental results of thermoluminescence and thermally stimulated conductivity of colour centres in NaF and NaF:Mg2+ crystals irradiated by electron beams with heavy doses. There are six glow peaks in the thermoluminescence of undoped NaF which are at 97, 142, 160, 210, 254 and 372 degrees C respectively. A glow peak at 77 degrees C and a single thermally stimulated conductivity peak at 47 degrees C are observed after optical bleaching using F-band light. In the case of crystals doped with MgF2, the peaks at 77 degrees C, 47 degrees C and another thermally stimulated conductivity peak at 250 degrees C are observed in the original sample without bleaching with F-band light. The features of these peaks and the role of Mg2+ in the thermoluminescence are discussed in detail.