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

In the present work the LaCoO 3 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 (H 2 O, CO 2 and NO 2 ) 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 (LaCoO 3 ). Some electri- cal properties of LaCoO 3 measured in "operando" conditions, i.e. in gas fl ow, at atmospheric pressure (by using the differential step technique DST) are presented and discussed.