Thermoluminescence study of Cu and Ag doped lithium tetraborate samples synthesized by water/solution assisted method

In this paper lithium tetraborate (Li₂B₄O₇) was produced by water/solution assisted synthesis method. Transition metals, such as Cu and Ag were used to dope Li₂B₄O₇ in order to enhance its thermoluminescent properties. The heating temperature parameters for synthesis were 750 degrees Celsius for 2 hours and 150 degrees Celsius for another 2 hours. The samples produced by water assisted method were doped at different doping percentage (0.08, 0.12, 0.5, 0.1 and 1%) of Cu and Ag. Pellets of samples were prepared and there were irradiated with different doses (58, 100, 500 and 945 mGy) by using and X-ray source. The characteristics of undoped and doped Li₂B-4O₇ were determined by X-ray diffraction (XRD), scanning electron microscopy (Sem), photoluminescence and ultraviolet-visible spectroscopy. The chemical composition and their morphologies of the obtained Li₂B₄O₇ and Li₂B₄O₇:Cu, Ag was confirmed by XRD and Sem results. The most intense peak of the XRD pattern of the lithium tetraborate sample was determined by comparing to the reference data and was found to have a tetragonal structure. The thermoluminescent glow curves of the pellets exposed to different doses exhibited a clear response to X-ray irradiation. Especially Li₂B₄O₇:Cu presented a good glow curve in all kind of doses. The experimental results showed that this could have good potential applications in radiation dosimetry. The order of kinetics (b), frequency factor (s) and activation energy (E) or the trapping parameters were calculated using peak shape method. (Author)