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Title: Defect equilibrium in PrBaCo{sub 2}O{sub 5+δ} at elevated temperatures

A defect equilibrium model for PrBaCo{sub 2}O{sub 5+δ} is suggested based on oxygen non-stoichiometry data. The model includes reactions of oxygen exchange and charge disproportionation of Co{sup 3+} cations. The respective equilibrium constants, enthalpies and entropies for the reactions entering the model are obtained from the fitting of the experimental data for oxygen non-stoichiometry. The enthalpies of oxidation Co{sup 2+}→Co{sup 3+} and Co{sup 3+}→Co{sup 4+} are found to be equal to 115±9 kJ mol{sup –1} and 45±4 kJ mol{sup –1}, respectively. The obtained equilibrium constants were used in order to calculate variations in concentration of cobalt species with non-stoichiometry, temperature and oxygen pressure. - Graphical abstract: Variations in concentration of cobalt species with oxygen content in PrBaCo{sub n}{sup 2+}Co{sub z}{sup 3+}Co{sub p}{sup 4+}O{sub 5+δ} at 650 °S. Display Omitted - Highlights: • The defect equilibrium model based on oxygen non-stoichiometry data is suggested. • Disproportionation of Co{sup 3+} cations gives significant contribution to defect equilibrium. • The hole concentration obtained from the model is in accord with electrical properties.
Authors:
 [1] ;  [1] ;  [2] ; ;  [1]
  1. Institute of Solid State Chemistry, Pervomaiskaya str.91, Ekaterinburg 620990 (Russian Federation)
  2. (Russian Federation)
Publication Date:
OSTI Identifier:
22274110
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 206; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CATIONS; COBALT; COBALT IONS; ELECTRICAL PROPERTIES; ENTHALPY; ENTROPY; OXIDATION; OXYGEN; PRASEODYMIUM