Optically stimulated luminescence of MgO:Na,Li phosphor prepared using solution combustion method

Abstract

Abstract The purpose of this study is to synthesize magnesium oxide polycrystals doped with sodium and lithium (MgO:Na,Li) using Solution Combustion Synthesis (SCS) technique for developing a storage material with required Optically Stimulated Luminescence (OSL) properties. In this work, we investigated the dosimetric and luminescence characteristics of the synthesized MgO:Na,Li ceramic in pellet form. The phase identification and morphology of the samples were performed using x-ray diffraction (XRD) and scanning electron microscope (SEM) analysis. The radioluminescence (RL) emission of the obtained MgO:Na,Li pellet samples showed two different emissions bands that are dominant at ∼730 nm, and with a weak and broad emission between 300 and 590 nm. The samples characterized by a Thermoluminescence (TL) glow curve having dominant TL peaks at around 80, 155 and 315 °C at a heating rate of 5 °C/s. We carried out a step-annealing procedure to investigate the depth of the trapping centers associated with the OSL signal. The thermally affected OSL traps seems to be originated mostly from practically a single deconvoluted TL peak between 170 and 250 °C with intensity comparable to Al2O3:C when Hoya U-340 filter was used. The stability of the OSL signal was tested for shorth-term and long-term fading in dark. We determined that the total OSL area decayed around 15% after 5 weeks. We evaluated the kinetic parameters of the MgO:Na,Li using the computerized glow curve deconvolution (CGCD), Tm-Tstop method and extended initial rise method (IRM) for the TL traps, and isothermal annealing method for the OSL traps. We presented MgO:Na5%,Li5% as a workable OSL material sensitive to ionizing irradiation with suitable dosimetric properties.