Synthesis mechanism of fine particle BaMgAl10O17:Eu2+ phosphor

Small particle size and well dispersed round cake-like α-Al2O3 powder was prepared by a chemical precipitation method, and fine particle, regular shape BaMgAl10O17:Eu2+ (BAM) phosphor was synthesized using the α-Al2O3 powder as a raw material. Phase transformation and particle growth processes were analyzed by the X-ray diffraction and scanning electron microscopy. The results show that the shape and size of the BAM phosphor particles have close association with the original α-Al2O3 particles, the BAM particles retain a cake-like shape with a size of 2.5 μm and a good dispersity after being calcined at 1 500 °C for 2 h in air. The results also show that a shell of BaAl2O4 phase is formed on surface of the α-Al2O3 particle when the temperature reaches 1 000 °C, and then MgO is involved in the reaction when the temperature increases. The mass transfer continues through BaAl2O4 shell, and eventually a pure BaMgAl10O17 phase is formed. The luminescence property of the BAM phosphor using the self-made alumina is similar to that using a commercial alumina powder.