Highly Conducting Redox Stable Pyrochlore Oxides

A(2)B(2)O(7) complex oxides with the pyrochlore structure feature a wide variety of chemical compositions and corresponding diverse electrical and physical properties. A new pyrochlore, Yb0.96Ca1.04TiNbO6.98, is reported and characterized in terms of structural stability and electrical properties. The material is stable to similar to 1450 degrees C in 5% H-2/N-2 and has a high electronic conductivity in a reducing atmosphere, e.g., 9 S/cm at 800 degrees C in 5% H-2/N-2 after high-temperature reduction. Other cation substitutions enhance the low-temperature kinetics of conductivity response to changes in oxygen partial pressure.