Mechanical stability and transport properties of the Sn-promoted SrCo0.8Fe0.2O3-δ ceramic membrane

In this article, the phase compositions, thermal, mechanical and transport properties of both the SrCo0.8Fe0.2O3-delta (SCF) and the SrCo0.8Fe0.1Sn0.1O3-delta (SSCF) ceramic membranes were investigated systematically. As compared with the SCF membrane, the SSCF one had a more promoted thermal shock resistance, which related to its small thermal expansion coefficient between them and an enhanced composite structure for it. For the SCF membrane, a permeation rate of 1.9 x 10(-6) mol cm(-2) s(-1) was obtained at 1000 degrees C and under the oxygen partial pressure gradient of P-O2 (h)/P-O2 (l) =0.209 atm/0.012atm; however, the permeation rate was 2.5 x 10(-6) mol cm(-2) s(-1) for the SSCF one in the same measuring condition. In addition, both peak values of total electrical conductivity (a,) for SSCF sample appeared with increasing temperature. The second peak value of sigma(e) for SSCF one was regarded as the contribution from its minor phase, which appeared with the mixed conducting behavior resulting from partly Co-dissolving into its lattice. (c) 2006 Elsevier B.V. All rights reserved.