Synthesis, thermoluminescence and dosimetric properties of La-doped zinc borates

Dependence on the dose of beta radiation of undoped and La-doped ZnB2O4 powder samples at 1%, 2%, 3%, 4%, 5% and 10% (by weight) was investigated by thermoluminescence technique. Powder samples were synthesized by the nitric acid method using the starting oxides [zinc oxide (ZnO), boric acid (H3BO3) and doped element oxide (La2O3)]. The samples were characterized by X-ray diffraction (XRD). The thermoluminescence (TL) properties of the powder samples were measured with Risø TL/OSL DA-20 reader. TL glow curves were obtained with heating at a constant heating rate of 5 °C/s up to 450 °C. The dose response curves of the powder samples exposed to 90Sr beta radiation (40 mCi) were obtained in the dose range from 143 mGy to 60 Gy. Dose responses and minimum detectable dose (MDD) values for increasing radiation doses of the powder samples were determined. The dose responses of all the samples have shown a quite linear response to beta radiation. MDD value of 10% La-doped ZnB2O4 powder sample which shows a high temperature peak at 207 °C was determined as 4 mGy. MDD values for 1%, 2%, 3%, 4% and 5% La-doped ZnB2O4 powder samples were also determined as 10 mGy, 50 mGy, 10 mGy, 10 mGy and 30 mGy, respectively. Luminescence intensities of the powder samples were shown to be likely to be used for low radiation doses. Highlights: ► Powder samples of undoped and La-doped zinc borate were prepared by the nitric acid method. ► TL properties and dependence on the dose of beta radiation of the samples have been investigated. ► The dose responses of the powder samples showed good linearity. ► The results showed that ZnB2O4:La sample can be a promising TLD material for dosimetric applications