【摘要】 讨论等离子体有机金属化学气相沉积(MOCVD)法制备纳米Al2O3粉末,同时研究了反应温度、压力、TMA浓度和反应气体(CO2和O2)等制备条件对Al2O3结构性能的影响。试验结果表明,压力增加有利于纳米Al2O3制备。在压力为5.3 kPa、温度为1 000℃下,采用MOCVD法可以制备平均直径为2.5 nm的Al2O3粉末。而压力从5.3 kPa增加到100 kPa时,Al2O3颗粒平均直径从2.5 nm增加到10 nm。温度升高可以促使纳米Al2O3合成。通过透射电镜(TEM)观测到Al2O3粉末为球形。X射线衍射分析(XRD)表明,在温度高于400℃时,Al2O3粉末为典型的-γAl2O3结晶态。更多还原

【Abstract】 Nanosized Al2O3 powder is synthesized by thermal MOCVD(metal organic chemical vapor deposition) combined with plasma.The effects of reaction temperature,pressure,TMA concentration and reactant gases(CO2 and O2) on the characteristics of the synthesized Al2O3 powder are investigated.The experimental results demonstrate that very fine Al2O3 powder with mean particle size of about 2.5nm can be obtained at 5.3 kPa reactor pressure and 1 000 ℃ by thermal MOCVD.As the pressure has increased from 5.3 kPa to 100 kPa,the mean diameter of Al2O3 powder also reaches 10nm.In other words,the increase in pressure has a negative effect on the synthesis of nanosized Al2O3.Meanwhile,it is also observed that the increment of temperature can promote the synthesis of fine Al2O3 powder.Furthermore,the powder morphology and crystallite size are examined by the transmission electron microscopy(TEM) and XRD and the particles are found to be in sphere shape.XRD analysis shows that the particles are typical γ-Al2O3 crystalline phase over 400 ℃.更多还原