Thermoluminescence Study of Nd3+ Doped Lanthanum Tri-Borate Phosphor

Abstract

This study investigates the thermoluminescence (TL) properties and trapping parameters of Nd³⁺ doped lanthanum tri-borate (LaB₃O₆) phosphors, synthesized through a low-temperature combustion method. The synthesized samples, doped with varying concentrations of Nd³⁺ (0.25%, 0.5%, 1%, 2%, 3%, and 5% by mass), were characterized using powder X-ray diffraction (XRD) to confirm their crystalline structure and matched LaB₃O₆ reference pattern in ICSD. The TL glow peaks of Nd³⁺ doped LaB₃O₆ subjected to 5 Gy beta radiation emerged notably at 75˚C, 125˚C and 257˚C, accompanied by shoulder above 320˚C. The optimal Nd³⁺ doping concentration for TL efficiency was 0.25%. TL response of LaB₃O₆:Nd³⁺ (0.25%) against doses ranging from 0.1 Gy to 750 Gy indicated excellent linear behavior up to 20 Gy (b=1.003, R²= 0.999). Ten cycles of reusability testing showed that the deviations did not exceed 2% for either the maximum TL intensity (I_m) or peak area variation. The TL signal faded by about 13% in 26 days of storage time. Various heating rates (VHR), T_m-T_stop, initial rise (IR), and computerized glow curve deconvolution (CGCD) methods were employed to ascertain the individual peak numbers and kinetic parameters of LaB₃O₆:0.25%Nd³⁺ sample. The CGCD result revealed that it is possible to distinguish five overlapped groups of components peaked at 249, 272, 303, 327 and 354 ^oC.