Luminescence enhancement of high temperature hexagonal phase of Ba0.99MgAl10O17: Eu0.01 nanophosphor synthesized at moderately low temperature

Photoluminescent (PL) properties of Eu2+-doped BaMgAl10O17 (BAM:Eu2+) phosphors are significantly influenced by its crystallanity, phase and regular morphology. To obtain a high brightness blue-emitting BAM:Eu2+ nanophosphor, a pH-controlled polymeric gel deflagration method was performed at 600 degrees C followed by post calcination at 1300 degrees C for 3 h under mild reducing atmosphere. It is one of the very few reports that depicts the formation of hexagonal phase of BAM:Eu2+ nanophosphor at relatively lower (-600 degrees C) temperatures, which is otherwise possible at very high (>1500 degrees C) sintering temperatures. A drastic improvement in crystallanity, phase, morphology and PL intensities has been achieved in BAM:Eu2+ nanophosphors with the addition of ammonium fluoride (NH4F) during post-calcination treatment. The presence of NH4F benefitted the thermal stability of BAM:Eu2+ nanophosphors as well. X-ray diffraction studies confirmed the phase purity while the scanning electron microscopy revealed regular morphology with non-aggregated nanoparticles. The improvement in crystallanity of BAM:Eu2+ nanophosphors led to almost four times increase in PL intensity in comparison to its bulk counterpart synthesized by solid-state reaction method. Intentional gamma irradiation of the samples for the creation of F+ centres is another unique feature studied in the current work. The obtained results clearly indicate that BAM:Eu2+ nanophosphor prepared in the study would be an ideal candidate for enhancing the properties of many active displays.

Automated summary

Eu2+-doped BaMgAl10O17 (BAM:Eu2+) phosphors exhibit significantly improved photoluminescent properties when synthesized using a pH-controlled polymeric gel deflagration method followed by post-calcination treatment with ammonium fluoride (NH4F). The addition of NH4F not only enhances the crystallanity, phase, morphology and PL intensity of the nanophosphors, but also improves their thermal stability. This study demonstrates the successful formation of the hexagonal phase of BAM:Eu2+ nanophosphors at relatively lower temperatures than traditional methods, and the resulting nanophosphors show potential for enhancing the properties of active displays.