Thermoluminescent properties of MgO co-doped with different lanthanides

This work presents results obtained from the synthesis of MgO:Sm co-doped with different lanthanides by the solution combustion method. With the obtained powders, dosimeters were manufactured in pellet form and sintered at 1173 K for 2 h. The highest sensitivity was found for the MgO:Sm,Tb sample, with 0.4 and 0.1 mol% of Sm and Tb, respectively. Another studied material, MgO:Ce,Dy, without Sm as dopant showed an interesting TL response. The MgO:Sm,Ce sample did not show any TL signal of interest because the Ce acts as an inhibitor of the TL signal. The MgO:Sm,Tb sample showed an increase of 100 % in sensitivity with respect to the MgO doped only with Sm, as well as linearity up to 500 Gy under ⁶⁰Co gamma irradiation. The lower detection limit (LDL) was found to be 0.12 mGy, with a coefficient of variability of 1.7 %. The TL signal of this material fades 2 % in the first 3 days, in which the TL readings are performed as a routinary dosimetric procedure. The PS method showed that the main peak observed in the glow curve of MgO:Sm,Tb, obtained at heating rates of 2, 5 and 10 Ks^-1, corresponds to general order kinetics. The SQPGCD method confirms that the dosimetric peak of MgO:Sm,Tb corresponds to general order kinetics. These results suggest that MgO:Sm,Tb is a promising TL material that could be used in dosimetric applications.