Comparative study of phase transformation of Al2O3 nanoparticles prepared by chemical precipitation and sol-gel auto combustion methods

Abstract

Al2O3 nanoparticles were prepared by Chemical Precipitation (CP) and Sol-Gel Auto Combustion (SGAC) methods and a comparative study on structural behaviour of the nanoparticles was carried out. Nanoparticles prepared by CP gradually transformed to the thermodynamically stable α-phase of alumina at an annealing temperature of 1100 °C whereas pure α-alumina directly obtained for the nanoparticles prepared by sol gel method during the combustion stage. Surface morphology showed the agglomeration of particles after calcining at a higher temperature. Nanoparticles prepared by SGAC method at low temperature showed the same thermal behaviour as those annealed at 1100 °C after being prepared by CP method.