AlN powder synthesis by sodium fluoride-assisted carbothermal combustion

AlN powders were prepared by combining sodium fluoride-assisted solution combustion with carbothermal reduction-nitridation. The effects of sodium fluoride on the nitridation reactivity, specific surface areas and morphology of the synthesized AlN powders were investigated in detail. The morphology of the AlN products changed from highly fluffy and porous networks into regular and hexagonal thin flakes, and the specific surface area decreased with the sodium fluoride content. No hard agglomeration could be found in decarburized AlN powders. The phase-pure AlN has been observed in all products calcined above 1300 °C, and no sodium was detected in the AlN powders by the X-ray fluorescence spectrometry.