Speaker
Description
Barium-substituted phosphor powders of (Ba1-xSrx)Al2O4:Eu2+ ;Nd3+ composition were prepared by combustion method at an initiating temperature of 5000C, using urea as reducer. The powders were then annealed at higher temperatures of 8000C and 10000C for 3 hours. Their crystallinity and phase were characterized by x-ray diffraction (XRD). The x-ray diffraction shows that the crystallinity of (Ba1-xSrx)Al2O4:Eu2+;Nd3+ at (x=0) greatly improved after annealing at the higher temperature of 10000C and shows the hexagonal structure that closely correspond with the JCPDS data (PDF#17-0306). The morphology of the (Ba1-xSrx)Al2O4:Eu2+;Nd3+ composition were investigated using Scanning Electron Microscopy (SEM). The effect of varying the Ba/Sr concentration on the thermoluminescence (TL) glow curves was investigated using the Thermoluminescence Reader (Integral-Pc Based) Nucleonix TL 1009I. Photoluminescence (PL) properties of all phosphor samples were investigated by measuring their emission spectra using a 325nm He-Cd laser. For the as-prepared phosphor samples, the sample with x=0 (BaAl2O4:Eu2+;Nd3+showed a much higher intensity compared to both the sample with x=1 (SrAl2O4:Eu2+;Nd3+and the mixed composition of the two. (BaAl2O4:Eu2+;Nd3+(x=0) and SrAl2O4:Eu2+;Nd3+ (x=1)showed a broad emission at 505nm and 522nm respectively while the mixed composition showed two peaks at 447nm and 517nm. The broad emission peaks attributed to 4f65d1-4f 7 transitions of Eu2+ were obtained. Their phosphorescence was investigated by using the fluorescence Cary eclipse spectrophotometer coupled with a xenon lamp. Phosphorescence show higher luminescence for (Ba1-xSrx)Al2O4:Eu2+;Nd3+at (x=0).
| Consider for a student <br> award (Yes / No)? | Yes |
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| Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)? | Yes |
| Level (Hons, MSc, <br> PhD, other)? | MSc |
