Energy trap dynamics and thermoluminescent behaviour of Sm3+-doped LaCa4O(BO3)3 under variable conditions

This study systematically explores the thermoluminescence (TL) properties of Sm³⁺-doped LaCa₄O(BO₃)₃ (LaCOB) phosphors, with emphasis on the effects of doping concentration, beta irradiation dose, and heating rate. The LaCOB host matrix, composed of borate-based compounds, is recognized for its thermal stability and efficient energy transfer characteristics. TL measurements conducted at a heating rate of 2 °C/s revealed three well-defined glow peaks at ∼81, 138, and 298 °C, respectively. The most favorable TL intensity was obtained at a doping concentration of 0.5 wt%, beyond which concentration quenching effects became prominent. Dose-response analyses exhibited both linear and super-linear trends, indicating potential for broad-range dosimetric applications. A notable increase in the integrated TL glow curve area with increasing heating rate was observed, suggesting a suppression of non-radiative pathways, possibly due to efficient charge carrier trapping and recombination mechanisms. The material also demonstrated remarkable reusability and thermal stability across repeated irradiation–readout cycles, reinforcing its potential for reliable radiation dosimetry. Kinetic analyses conducted via Glow Curve Deconvolution (GCD) yielded activation energies in the range of 0.85–1.82 eV, confirming the presence of multiple trapping centers with stable thermal behavior.