Crystallization of ceramic pigment CoAl2O4 nanocrystals from Co-Al metal organic precursor

We synthesized ceramic pigment CoAl2O4 nanocrystals by a polymerized complex technique. Cobalt nitrate, aluminum nitrate, citric acid, and ethylene glycol were used as precursor materials. The formation of pure crystallized CoAl2O4 nanocrystals occurred when the precursor was heat-treated at 350 degrees C in air for 2 h. We propose a model for CoAl2O4 formation from the polymeric precursor. The model contains a series of steps such as the transformation of the precursor to amorphous cobalt aluminate, three-dimensional nucleation and growth, and solid-state reaction. (C) 1999 Elsevier Science S.A. All rights reserved.