Production of Conducting Oxide Powders by Amorphous Citrate Process

Abstract

The amorphous citrate process has been used to produce Co₃O₄, CoO, Cr₂O₃, LaCoO₃, LaCrO₃, SrCoO₃, and strontium-doped LaCoO₃, and LaCrO₃. The citrate-nitrate gels were produced at room temperature and dehydrated at 70°C to yield solid precursor materials. The decomposition of the precursors was studied at temperatures of 220, 310, 500,710, 880, and 1060°C. The yield of the process for strontium-doped lanthanum cobaltite is of the order of 90% which compares extremely well with the yield of 60% obtained by the conventional powder technique. Thermogravimetry, X-ray diffraction analysis, scanning electron microscopy, and analytical electron microscopy have been used to characterize the precursors and oxide materials produced by the citrate process.