Physicochemical properties of non-stoichiometric oxides Mixed conductors: Part I

L. MOGNI; N. GRUNBAUM; F. PRADO; A. CANEIRO

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY

SPRINGER

Lugar: Berlin; Año: 2011 vol. 103 p. 597 - 606

1388-6150

This is the first part of a review devoted topresent the physicochemical properties of non-stoichiometricoxides that exhibit simultaneously ionic and electronicconductivity. Oxides mixed conductors are candidates to beused in electrochemical applications such as oxygen separationmembranes, Solid Oxide Fuel Cells (SOFC) andSolid Oxide Electrolysis Cell (SOEC). In the present article,divide in two parts, we review the thermodynamic andtransport properties of mixed conductors systems. In Part Iis presented the layered mixed conductors Sr3FeMO6?d(M = Fe, Co, Ni) belonging to the n = 2 member of theRuddlesden?Popper series An?1BnO3n?1, while in Part IIwe discuss results obtained for the Sr1-xLaxFe0.2Co0.8O3-dperovskites. These perovskite related intergrowth oxides,Sr3FeMO6?d, intercalate rock-salt layers in the perovskitestructure decreasing the tendency of structural transformationat high temperature. The defect structure of thesematerials has been determined by thermodynamicmeasurements of the oxygen chemical potential (lO2) as afunction of oxygen content and temperature. The knowledgeof the defect structure has shown to be essential toanalyze electrical resistivity measurements and neutronpowder diffraction data at high temperature to proposemechanisms for the electronic and ionic transport.