Lawrence Berkeley National Laboratory

The effective oxygen conductivities in the zirconia networks of porous LSM-YSZ and LSM-SYSZ composites [i.e. La0.85Sr0.15MnO3 (Y2O3)0.08(ZrO2)0.92 and La0.85Sr0.15MnO3-c2O3)0.1(Y2O3)0.01(ZrO2)0.89, respectively] were evaluated by an AC impedance technique using specimens in which LSM was removed by hydrochloric acid leaching. The oxygen conductivities of porous YSZ and SYSZ alone followed a Koh-Fortini relationship. LSM-containing zirconia network conductivities were additionally decreased by the presence of the LSM, presumably by increased grain boundary resistances. Constriction resistances were estimated to have a minor effect.