前驱体法合成氮化铝纳米材料及其生长机制

Al(CON₂H₄)₆Cl₃ was firstly synthesized as a precursorwith urea and AlCl₃•6H₂O as a nitrogen source and an aluminum source, respectively, and then the precursor was calcined at 1000℃ to prepare spherical h-AlN nanoparticles. The effects of atmosphere pressure and sintering time on the morphology and the nucleation-growth mechanism of AlN were investigated. The results show that spherical AlN particles with the sizes of 320-460nm are formed by equiaxed fine grains of smaller than 10nm and amorphous phase under N₂ pressure of 0.1-0.2MPa. As the N₂ pressure increases to 0.5MPa, the diameter of spherical AlN increases to 650nm, and rod-shaped AlN crystals appear in the aggregates. The size and number of rod crystals increase as the sintering time increases. AlN nanoparticles are formed by the reaction of AlCl₃ and NH₃ due to the decomposition of the precursor. The gas phase saturation in the crucible increases as N₂ pressure increases, promoting the nucleation and growth of AlN, reducing the amorphous phase content, and enhancing the crystallinity of AlN.