Determination of Oxygen Nonstoichiometry and Diffusivity in Mixed Conducting Oxides by Oxygen Coulometric Titration. II Oxygen Nonstoichiometry and Defect Model for La0.8Sr0.2CoO3-delta

Lankhorst, M.H.R. and Bouwmeester, H.J.M. (1997) Determination of Oxygen Nonstoichiometry and Diffusivity in Mixed Conducting Oxides by Oxygen Coulometric Titration. II Oxygen Nonstoichiometry and Defect Model for La0.8Sr0.2CoO3-delta. Journal of the Electrochemical Society, 144 (4). pp. 1268-1273. ISSN 0013-4651

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Abstract:	The oxygen nonstoichiometry of La0.8Sr0.2CoO3-delta has been determined as a function of oxygen partial pressure and temperature using a high-temperature coulometric titration cell. For each measured value of the oxygen chemical potential, the oxygen nonstoichiometry is found to be nearly independent of temperature. The equilibrium partial energy and entropy associated with oxygen incorporation have been determined as a function of oxygen nonstoichiometry and temperature. The results are interpreted in terms of a model in which it is assumed that conduction electrons, created during vacancy formation, gradually fill electron states in a wide electron band. A new relation between vacancy concentration, temperature, and oxygen partial pressure has been formulated which does not have the familiar appearance of a mass action type of equation.
Item Type:	Article
Copyright:	The Electrochemical Society
Faculty:	Science and Technology (TNW)
Research Group:	Inorganic Membranes (IM)
Link to this item:	http://purl.utwente.nl/publications/61586
Official URL:	http://dx.doi.org/10.1149/1.1837581
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Metis ID: 106486