Production of Strontium-Doped Lanthanum Cobaltite Conducting Oxide Powder by Freeze-Drying Technique

Abstract

The freeze-drying of mixed nitrate solutions has been used to produce lanthanum cobaltite and strontium-doped lanthanum cobaltite. The freeze-dried nitrates were decomposed in vacuum at 500°C and the residue heat-treated for one hour at 1060°C. The yield of the freeze-drying process is shown to be the same as that of a commercial process involving the repeated sintering and milling of a carbonate/oxides mixture. X-ray diffraction analysis, scanning electron microscopy, and analytical electron microscopy have been used to characterize both the freeze-dried material and the commercial material.