Preparation and characterization of SrFeCo0.5O3.25+delta by gelcasting

SrFeCo0.5O3.25+delta powders have been successfully synthesized from SrCO3, 2CoCO(3). 3Co(OH)(2). xH(2)O and Fe2O3 based on using the principle of gel casting. Thermal decomposition of the gelcasting powder was analyzed by dif ferential thermal analysis and thermogravimetry. The crystal structure of t he sintered body was investigated by X-ray diffraction. It was found that S rFeCo0.5O3.25+delta samples formed by sintering the gelcasting powder over 1000 degreesC consist mainly of the perovskite phase SrFe1-xCoxO3-delta. El ectrical conductivity was measured by a DC four-probe technique and oxygen permeation flux was measured by applying oxygen partial pressure difference to a 1.4 mm thick pellet. Both the electrical conductivity and oxygen perm eation flux of the gelcasting samples were much higher than that of samples prepared by a traditional solid state reaction method. Though further work should be performed on the higher transfer velocity of electron and oxygen ion, experimental data shows that the gelcasting process is a promising te chnique for the preparation of mixed conducting SrFeCo0.5O3.25+delta. (C) 2 001 Elsevier Science Ltd. All rights reserved.