The role of Mg²⁺‐V‐dipoles: In the thermoluminescence of LiF₂:Mg single crystal

The thermoluminescence and radiation or thermally induced changes of the concentration of magnesium dipoles have been studied in LiF:Mg²⁺ crystal grown in an inert atmosphere. The evolution of the TL spectrum with γ‐radiation dose shows that the glow peaks observed at the beginning of irradiation decrease at high doses whereas new peaks, positioned at higher temperatures, appeare. Moreover, it has been found that the thermally induced recovery of the dopant dipoles, destroyed during the irradiation, strongly depends on the dose applied. The recovery curves obtained for a fixed irradiation dose dose not exhibit thermal annealing steps at temperatures, at which glow peaks occur. Further, the number of the recovered magnesium dipoles is not correlated with the quantity of light emitted during heating the irradiated crystal what is expected in respect to some of the previously proposed models. On the basis of results obtained it is proposed that the decay of the magnesium dipoles is mainly due to the dopant aggregation induced by the γ‐radiation. The role of the magnesium ions in thermoluminescent processes is discussed.