characterization of nanosized al2o3 powder synthesized by thermal-assisted mocvd and plasma-assisted mocvd

nanosized al2o3 powder is synthesized by thermal metal organic chemical vapor deposition (mocvd)combined withplasma. the effects of reaction temperature, pressure, al(ch3)3 (tma) concentration and reactant gases (co2 and o2) on the characteristics of the synthesized al2o3 powders are investigated. the experimental results demonstrate that very fineal2o3 powders with mean particle size of about 2.5 nm can be obtained at 5.3kpareactor pressure and 1000 ocby the thermal mocvd. as the pressure is increased from 5.3kpa to 100 kpa, the mean diameter of al2o3 powders also reaches to 10 nm. 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.