Abstract
Nanophosphors of barium strontium sulfate complex (Ba1-xSrxSO4)(99.8%):Eu-0.2% (0 <= x <= 1) were prepared through the chemical co-precipitation method at room temperature. Precipitated samples were characterized using X-ray diffraction (XRD), dynamic light scattering (DLS) and high resolution transmission electron microscope (HRTEM) techniques. The obtained XRD patterns from the prepared nanophosphate series (Ba1-xSrxSO4)(99.8%):Eu-0.2% exhibit an orthorhombic structure with semispherical particle shape. The lattice parameters of (Ba1-xSrxSO4)(99.8%):Eu-0.2% solid crystals change and the cell volume decreases with the increase of x value of strontium. The thermoluminescence (11) glow curves induced by gamma rays of (Ba1-xSrxSO4)(99.8%):Eu-0.2% series were recorded and compared. The substitution of Ba2+ by Sr2+ cations shift the trap centers in the host of (Ba1-xSrxSO4)(99.8%):Eu-0.2% material to the higher temperature side. The TL glow curve (GC) of sample with x = 0.12, with grain size ranging between 13-31 nm, reveals that it has deep trap centers, and higher TL sensitivity. The different heating rates effect of the glow peaks of samples with x = 0, 0.12 and 1 showed that they follow the first-order kinetics. These samples have been studied and analyzed with the help of both T-stop experimental method, and the computerized glow curve deconvolution (CGCD) program. T-m-T-stop experiment indicates that there are three trapping levels in both (BaSO4)(99.8%):Eu-0.2% and (SrSO4)(99.8%):Eu-0.2% sulfate samples at 452, 489, 543 K and 487, 513, 530 K respectively, while five peaks at 458, 486, 499, 544 and 556 K in the complex GC of (Ba(0.88)St(0.12)-SO4)(99.8%):Eu-0.2%. These values are used as input for CGCD. The figure of merit (FOM) during fitting procedures is determined. (C) 2014 Elsevier Ltd. All rights reserved.