Characterization of europium-doped strontium zirconate SrZrO₃: Eu3+ as a material for use in dosimetry

In the study of thermoluminescent materials for dosimetry, due to its high sensitivity to radiation, calcium sulfate doped with dysprosium (CaSO₄), calcium fluoride doped with manganese (CaF₂), alumina (Al2O₃) and lithium fluoride doped with magnesium and titanium (LiF:Mg,Ti) are proposed. Perovskite compounds (ABX3) are known for their diversity of physical properties, including thermoluminescence (Tl), especially when doped with suitable activators; considerable experimental work has been carried out on these materials, pure or doped with rare earth or transition metal impurities. Zirconium-based perovskites are gaining wide recognition in the research field, due to their high chemical and thermal stability, high melting point and small thermal coefficient; along with these electrical properties, SrZrO₃ perovskites are also reported to have luminescence properties. For this work, SrZrO₃ powders were prepared by hydrothermal method doped with Eu3+ ions (1, 3, 5, 7, 10 and 15 mol %). The results obtained from the characterization of strontium zirconate SrZrO₃ are presented as a proposal to be used as an ionizing radiation detector for use in dosimetry. The phase of the compound, as well as the average particle size, was determined by X-ray diffraction (XRD). Prior to Tl measurements, samples were subjected to heat treatment at 350 °C for 20 min to erase any information. Tests were carried out on the powders obtained to determine their sensitivity to betas, the samples corresponding to the different percentages of Eu3+ were mounted and exposed using the Lexsyg Smart equipment equipped with a source of Sr-90/Y-90, and with a rapid dose of 110 mGy/s, Tl measurements were performed on the same equipment. The optimal concentration of the Eu3+ ion as doping material in the SrZrO₃ matrix was 5%. The Tl curve of dust exposed to beta radiation showed two peaks centered at 130°C and 295°C. The Tl response as a function of beta radiation dose presented a proportional response with increasing dose. (author)