ELECTRICAL CONDUCTIVITY OF PEROVSKITES IN THE QUASI-TERNARY SYSTEM La_(0.8)Sr_(0.2)MnO_3 - La_(0.8)Sr_(0.2)CoO_3 - La_(0.8)Sr_(0.2)FeO_3 FOR APPLICATION AS CATHODE-INTERCONNECT CONTACT LAYER IN SOFC

摘要

La_(1-x)Sr_xMeO_3 (Me = Mn, Co, Fe) perovskites are interesting materials for application as cathode-interconnect contact layers in solid oxide fuel cells. The objective of this contribution is to give an overview on the variation of the electrical conductivity as a function of composition within the quasi-ternary system La_(0.8)Sr_(0.2)MnO_3 -La_(0.8)Sr_(0.2)CoO_3 -La_(0.8)Sr_(0.2)FeO_3 at 800 deg C in air. Various nominal perovskite compositions within this system were selected through systematic experimental design and synthesized under identical conditions by the Pechini method. The powder XRD data obtained on these powders are collectively presented for the first time. The distribution of the different crystallographic phases at 900 deg C and 1100 deg C within this ternary system is shown. The DC electrical conductivity values (a) of the different compositions as a function of temperature are also presented. The apparent electrical conductivity values obtained were corrected by measuring the porosity by means of Archimedes' method for all the test specimens.