Thermoluminescence characterization of europium doped gadolinium aluminum borate phosphors: Impacts of europium doping under beta irradiation

In this study, the thermoluminescence (TL) characteristics and kinetic parameters of Eu³⁺ activated GdAl₃(BO₃)₄ (GAB), synthesized via the sol-gel method, were examined. The impact of Eu³⁺ doping on the crystal structure of undoped GAB was analysed using X-ray diffraction (XRD). The doped GAB retained its rhombohedral crystal structure, consistent with the PDF#72–1985 standard. The glow curves of the Eu³⁺ doped GAB phosphors revealed three distinct peaks at approximately 86 °C, 185 °C, and 300 °C. Among these, the phosphor with the highest TL sensitivity was 1 wt% Eu-doped GAB. The optimal heating regime to erase the TL signal at the 86 °C peak was determined to be heating 135 °C for 16 s. The TL signal exhibited a fading of 14.71 % over three-month period. The minimum detectable dose (MDD) was calculated to be 1.290 ± 0.02 mGy, indicating its suitability for low radiation dosimetry. The dose response of the phosphor showed linearity over a wide range of doses (2–300 Gy), with the phosphor's sensitivity remaining stable across the tested dose range. E_a-T_stop analysis identified six peaks with activation energies ranging between 0.99 eV and 1.18 eV, further confirming material's suitability for dosimetry applications.