Materials Science Forum, Vol.514-516, 387-391, 2006
Transport properties and thermal expansion of SrCe(Y)O3-delta ceramics
Oxygen transport properties of perovskite-type SrCe1-xYxO3-delta (x = 0.05-0.10), exhibiting protonic transport in hydrogen-containing reducing atmospheres and mixed oxygen-ionic and p-type electronic conductivity at oxygen partial pressures close to atmospheric, were studied at 9731223 K under oxidizing conditions. The oxygen transference numbers of SrCe(Y)O3-delta in air vary in the range 0.37-0.80, decreasing when temperature increases. The oxygen permeability is significantly affected by the hole conduction, which influences both bulk ambipolar conductivity and surface exchange kinetics. The average thermal expansion coefficients of SrCe1-xYxO3-delta ceramics, calculated from dilatometric data in air, are (11.1-11.3)x10(-6)K(-1) at 373-1373 K.
Keywords:strontium cerate;perovskite;mixed conductivity;proton transport;oxygen permeation;faradaic efficiency