A simple sol-gel technique for preparing lanthanum oxide nanopowders

Nanosized lanthanum oxide powders have been prepared by a simple sol-gel technique using commercial lanthanum oxide, nitrate acid and polyethylene glycol (PEG) as the starting materials. The decomposition process of dried gel powders were investigated by differential thermal and thermogravimetric analysis(TG-DSC). The crystalline structures and morphologies of the powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The effects of calcination temperature, calcination time, stirring and the concentration of PEG on the particle size were studied. The results show that the calcination temperature and concentration of PEG have obvious influence on the La2O3 particle size and agglomeration tendency. At lower calcination temperature the prolongation of calcination time has slight influence on the particle size. Stirring will promote the growth of particles. The weak-agglomerated nanosized powders with the mean particle size less than 40 ran could be obtained by controlling the process condition. (c) 2006 Elsevier B.V All rights reserved.