Particle Size Control and Characteristics Analysis of Nanosized γ-Alumina Powders

抄録

Nanosized Al₂O₃ particles were synthesized using the thermal CVD (Chemical Vapor Deposition) method. AlCl₃ (Trichloroaluminum) was used as the starting material. The relationships between particle size and reaction temperature, and concentration and pressure were investigated. In the preparation of nanosized Al₂O₃ particles, the typical γ-Al₂O₃ crystalline phases appeared above 1273 K. The particle size decreases from 8.2 nm to 3.7 nm with reaction pressure in the range of 101 kPa to 42.5 kPa. We obtained the smallest average particle size of 3.7 nm with geometric standard deviation of 0.8 nm. TEM observation shows that particles are spherical in shape. The size was also found to decrease from 8.9 nm to 6.1 nm when the reaction temperature was increased from 873 to 1273 K in an AlCl₃ concentration of 0.014 mol%. The uniformity of Al₂O₃ particles increased and decreased AlCl₃ concentrations and reaction pressures.