The effect of synthesis and doping procedures on thermoluminescent response of lithium tetraborate

Research highlights: → Thermoluminescence dosimetry has been a research interest for decades and is used to measure radiation exposure in a variety of areas. There are numerous materials produced by different methods to be used in commercial dosimeters. → The major point in medical or personnel dosimetry is the tissue equivalency which occurs when the dosimeter has an effective atomic number near that of human tissue (7.4). → The thermoluminescent response of a material is evaluated by the glow curve recorded and a stable glow peak around 200 deg. C is expected for a dosimetric material. → The synthesized materials are exposed to several test to determine thermoluminescent properties such as sensitivity, annealing, fading, linearity, etc. A good dosimeter is expected to have high sensitivity, easy annealing procedure, no fading for the main peak, low threshold dose, non-toxic, cheap and available. - Abstract: Lithium tetraborate has been a scientific focus since 1960s by the courtesy of the thermoluminescence property it possesses. Moreover, it is utilized in surface acoustic wave apparatuses, in sensor sector and in laser technology owing to its non-linear optical characteristics. For the uses in thermoluminescence dosimetry lithium tetraborate is activated by addition of a variety of metals as dopants. This study includes the synthesis of lithium tetraborate by two methods (high temperature solid state synthesis and water/solution assisted synthesis), doping of activators into the matrix material synthesized and characterization of the products. Lithium tetraborate is readily commercially available in TL (Themoluminescence) dosimetry; hence, the main aim in this study was to specify the effect of synthesis and doping methods on the TL response. The heating temperature for the synthesis was 750 deg. C and the retention time as selected as 4 h for both methods. The synthesis stages were followed by doping step where the compounds of Cu, Ag and In in different proportions were doped in lithium tetraborate by solid state and solution assisted doping techniques. Characterization of the product was achieved by X-ray diffraction (XRD), Fourier transform Infra Red Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) techniques. All samples prepared displayed TL response and the best TL signal was obtained from the sample produced by solid state synthesis and doped by solution assisted method with 0.1% Cu and 0.004% Ag.