Electron-Trap model: TL mechanism in BaSO4 nanophosphor-A new approach

Barium sulphate nanophosphor was synthesized through the water-ethanol (70 vol%) mixed solvent system by varying the concentration ratios of the basic reagents. The optimum concentration of the basic reagents was fixed on the basis of minimum crystalline size through X-ray diffraction (XRD) analysis. The Field Emission Scanning Electron Microscopy (FESEM) analysis shows that the particles are in spherical shape without agglomeration and the size is around 30 nm. The TL glow curve measurements were carried out for as synthesized sample (different doses) and different annealing temperatures (100-1000 degrees C). From annealing process, 800 degrees C is the optimum temperature for getting maximum TL intensity. The possible mechanism for getting the TL glow curve is explained briefly through the Electron-Trap model. Further, the structural and morphological characterizations of 800 degrees C annealed sample were carried out through XRD and FESEM analyses. The results show no structural changes. However, increase in crystalline size is noticed for annealed sample (around 50 nm) compared to the unannealed (around 30 nm) one. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.