煅烧温度对湿化学法制备AlN粉体的影响

以六水合氯化铝和尿素为原料,甲醇为溶剂,在NH₃气氛下通过湿化学法制备AlN粉体,并采用X射线衍射仪、扫描电子显微镜和激光粒度仪对产物进行表征。结果表明:煅烧温度在900 ℃以上可获得六方AlN粉体;煅烧温度为1 000 ℃时获得的AlN粉体具有球形特征,粉体的平均晶粒尺寸为17.0 nm,平均粒径为159.5 nm。使用透射电子显微镜进一步表征了AlN粉体的微观结构。拉曼光谱结合能谱分析表明,存在于AlN粉体中的非晶杂质不是残留的含碳副产物,而是粉体表面水解产生的氢氧化铝。

Effect of Calcination Temperature on AlN Powder Prepared by Wet Chemical Method

AlN powder was prepared by wet chemical method in NH₃ atmosphere using aluminum chloride hexahydrate and urea as raw materials and methanol as solvent. The products were characterized by X-ray diffractometer, scanning electron microscope and laser particle size analyzer. The results show that hexagonal AlN powders with high purity are obtained when the calcination temperature is above 900 ℃. The product obtained at 1 000 ℃ presents spherical characteristics, whose average crystallite size and particle size are 17.0 nm and 159.5 nm. The microstructure of AlN powder was further characterized by high-resolution transmission electron microscope. Combined with selective electron diffraction and Raman spectroscopy, it is further confirmed that the amorphous impurities existing on the surface of AlN powders are not residual carbon generated in high temperature reducing atmosphere, but should be attributed to alumina hydroxide generated by hydrolysis on the surface of AlN powders.