Synthesis of lanthanum cobaltite (LaCoO 3) by the polymerizable complex route

Abstract

We report a simple technique for preparation of lanthanum cobaltite LaCoO 3 powders by the polymerizable complex (PC) method based on the Pechini-type reaction route. A mixed solution of citric acid (CA) and ethylene glycol (EG) with La and Co ions was polymerized. The final materials obtained by the polyesterification between CA and EG were compared with those obtained by the nonpolymerizable route using only CA as complexant, without EG. The formation mechanism, homogeneity and the structure of the obtained powders have been investigated by thermogravimetry, X-ray diffraction and scanning electron microscopy (SEM) measurements. X-ray diffraction results indicated the formation of LaCoO 3 (rhombohedral) when the La–Co polymeric precursor was treated at 600 °C for 6 h. A better mixing of La and Co cations was achieved in the PC-derived precursor than in the precursor derived from the nonpolymerizable, amorphous citrate route.