Combustion synthesis of hexaaluminate phosphors

Green phosphors of the composition Ce1-xTbxMgAl11O19 (0.1 < x < 0.6) were p repared via self-propagating (combustion) synthesis, using urea as a fuel. The phosphors that were produced via the combustion route were fine powders and produced a luminous intensity of 72%, compared to an optimized commerc ial phosphor, The excitation spectra were characteristic of the Ce3+ cation ; however, no Ce3+ emission was observed. Energy transfer from the Ce3+ cat ion to the Tb3+ cation was complete, and only the 542 nm Tb3+ emission was observed. Concentration quenching occurred with x > 0.5, Scanning electron microscopy images showed a well-crystallized, platelike morphology, with a particle size of 10-20 mu m.