Size and morphology control of Y2O3 nanopowders via a sol-gel route

The present paper deals with the preparation of nanometric yttria powders. A sol-gel method has been adopted to synthesize a precursor gel which, after being heated, leads to Y2O3. Two main parameters are taken into account: the nature of the chelating agent and the [chelating agent]/[Y] relative concentration. The influence of these parameters on the composition and crystallization state of the precursor gel has been studied in the first part and on the grain morphologies of the resulting yttria powder in the second part. It has been shown that, depending on the chelating agent, nanometric powders presenting either needles, platelets or spherical shapes can actually be obtained at 800degreesC or 1100degreesC. (C) 2003 Elsevier Science (USA). All rights reserved.