Phase formation and electrical properties of the LaCoO3 obtained by water-based sol-gel method with citric acid

Abstract

In the present work the LaCoO3 formation from gel precursors obtained by water-based sol-gel method with citric acid was studied. As precursors La and Co nitrates were used. The obtained gels were analyzed by TG/DTA and TG/EGA. The decomposition of the gels takes place in two main steps with the evolution of the same volatile compounds (H2O, CO2 and NO2) leading to the conclusion that two types of bonding of the components in the gels occurred. The decomposition of the gels takes place up to 400°C. The gels thermally treated at 600°C lead to single pure perovskite rhombohedral phase of lanthanum cobalt oxide (LaCoO3). Some electrical properties of LaCoO3 measured in “operando” conditions, i.e. in gas fl ow, at atmospheric pressure (by using the differential step technique DST) are presented and discussed.

Keywords

• Sol-gel method
• LaCoO3
• Electrical properties