Synthesis of MgB₄O₇:Dy³⁺ and thermoluminescent characteristics at low doses of beta radiation

The synthesis and thermoluminescent characteristics of dysprosium-doped MgB₄O₇ are analyzed. The phosphor at different concentrations (0, 0.1, 0.5, 1, 2 and 4 mol%) of the dopant was prepared by the solution-assisted method. The magnesium borate compound was confirmed by X-ray diffraction. The annealing and dopant concentrations effects on the crystalline matrix were investigated. The highest thermoluminescent sensitivity was found with 450°C of annealing temperature and at high Dy³⁺ concentration too. The un-doped MgB₄O₇ phosphor shows a broad glow curve which peaked at 199 °C and about 306 °C. Introducing Dy³⁺ dopant in the matrix that behavior was strongly changed. The wide glow curve shows three glow peaks; two small shoulders at 124 and 195 °C, and a highest peak between 323 and 336 °C temperature range. A large linear dose-response (5 - 2000 mGy) beta dose was obtained. The complex glow curves were deconvolved and the kinetics parameters were determined considering the general order kinetics model. (author)