Defect structure of yttria-stabilized zirconia and its influence on the ionic conductivity at elevated temperatures

Abstract

The defect structure of cubic fluorite structured yttria-stabilized zirconia (ZrO2)(1-x)(Y2O3)(x) has been investigated over the composition range 0.100(3)less than or equal to x less than or equal to 0.241 (10) and temperatures T(K) up to 2780(10) K, using single-crystal specimens. Analysis of neutron and x-ray diffraction data, including both Bragg and coherent diffuse scattering components, has identified three principal types of defects within the fluorite lattice. At low yttria concentrations (xsimilar to 1000 K and give rise to the high ionic conductivity of the material. In light of these observations, we propose that the anomalous decrease in the ionic conductivity with increasing x is a consequence of the decreasing mobility of the isolated defects, possibly due to blockage by the increasing number of static aggregates. [S0163-1829(99)05621-0].