Conductivity and stability of SrVO3 and mixed perovskites at low oxygen partial pressures

The electrical conductivity and chemical stability of ABO(3) (where the A-site contains La or Sr, and the B-site contains Ni, V, Ti, Nb, Mo or W and combinations thereof) have been studied in air and reducing atmospheres. Neither the rare-earth vanadates, such as LaVO3, nor the alkaline-earth vanadates, with the exception of SrVO3, are good electronic conductors. SrVO3 shows excellent electronic conductivity of 1000 S/cm at 800 degreesC and an oxygen partial pressure of 10(-2) unstable under more oxidizing conditions. However, strontium-doped lanthanum vanadates are stable over a range of oxygen partial pressures of 10(-14)-10(-20) atm. La0.7Sr0.3VO3-delta has a conductivity of 50 S/cin at 800 degrees C and P-O2 = 10(-20) atm. However, none of the compounds studied have both adequate high-temperature electrical conductivity in reducing atmospheres and stability to cycling between oxidizing/reducing conditions, to serve as anodes in solid oxide fuel cells. (C) 2001 Elsevier Science B.V. All rights reserved.