Processing and electrochemical properties of mixed conducting La(sub 1-x)A(sub x)Co(sub 1-y)Fe(sub y)O(sub 3-(delta)) (A=Sr, Ca)

摘要

Powder compositions in the series La(sub 1-x)A(sub x)Co(sub 1-y)Fe(sub y)O(sub 3-(delta)) (A = Sr, Ca) have been prepared by a combustion synthesis method. Sintering of pressed powders produced high-density test specimens with the perovskite structure. The specimens exhibited high electrical conductivities with appreciable oxygen-ion conductivity that increased with Co content for the compositions studied. Oxygen permeation studies showed a significant flux of oxygen that increased with temperature for specimens in a P(O(sub 2)) gradient with no applied field. Thermogravimetric studies of the La(sub 1-x)Sr(sub x)Co(sub 0.2)Fe(sub 0.8)O(sub 3-(delta)) system indicated a reversible mass loss with increasing temperature that increased with Sr content.