Thermoluminescent Response of Nanocrystalline Licabo3:sm3+ Phosphor Synthesized by Solid State Reaction for Gamma Dosimetry

Abstract Thermoluminescence (TL) dosimetric properties and kinetic parameters of nanocrystalline LiCaBO₃:Sm³⁺ (0.3 mol %) powder sample synthesized by solid state reaction method and thermally annealed at 700°C/1h were investigated for the first time. XRD confirmed the single-phase orthorhombic (space group Pbca) structure of LiCaBO₃:Sm³⁺ having 19 nm crystallite size. FESEM showed porous, agglomerated particles forming hexagonal flake-like sheets (~ 34 nm thick), and EDS verified Sm³⁺ incorporation. FTIR and Raman spectra indicated characteristic (BO₃)³⁻ vibrational modes. UV-Vis analysis revealed a direct bandgap of 3.34 eV. Radiation-induced interaction parameters including attenuation coefficients and effective atomic numbers were theoretically evaluated. Samples were irradiated at various doses from Cs-137 γ-source with dose rate of 27.5 Gy/h. This phosphor exhibits a dominant composite TL peak around 187°C, surpassing those of rare earth doped LiCaBO₃, and lies within the optimal dosimetric range, enhancing sensitivity compared to existing variants. TL glow curve of this phosphor, irradiated by ¹³⁷Cs γ-rays at 20 Gy dose, measured at heating rate of 10°C/s has 5 deconvoluted glow peaks leading to highly dense trap at 181°C. TL kinetic parameters for the prepared material were evaluated using Chen’s peak shape method. Moreover, the TL response for gamma radiations dose was found to be linear from 0–20 Gy. Based on these experimental results and theoretical calculations, it is concluded that LiCaBO₃:Sm³⁺ (0.3 mol %) has a good potential for TL dosimetry.