Oxygen content determination in perovskite-type cobaltates

Three oxygen content determination methods (iodometric titration, gas volumetric analysis and thermogravimetric hydrogen reduction) have been evaluated for the case of rare earth cobaltates LnBCo(2)O(5+delta) (were Ln-rare earth, B-alkali earth elements). All the methods are based on oxidation properties of both Co4+ and Co3+ cations but different instrumentation was used for each of the method. We have obtained good agreement within +/-0.02 in delta for both the iodometric titration and the gas volumetric analysis, whereas the thermogravimetric hydrogen reduction was found to be less credible. (C) 2004 Elsevier Ltd. All rights reserved.