Electrical conduction and oxygen transport in SrFeCo0.5Ox oxide membranes

Electrical and oxygen transport properties of SrFeCo0.5Ox oxide were invest igated at elevated temperatures. The electrical conductivity was found in t he order of 20-10 S/cm in the temperature range of 1100-600 degreesC. An ab normal region was observed at temperatures around 900 degreesC in which ele ctrical conductivity increased with decreasing temperature, which may be re lated to the undergoing of phase transformation. An oxygen permeation flux of 159 x 10(-8) mol/cm(2).s was measured in an air/helium gradient at 900 d egreesC. The acid treatment on the sintered oxide resulted in a considerabl e improvement of the oxygen permeability, indicating that the surface oxyge n exchange limits the overall oxygen permeation process. (C) 2000 Elsevier Science B.V. All rights reserved.