High-temperature deformation of BaCe1-xYxO3-y (0.05 <= x <= 0.2)

Compressive high-temperature deformation of BaCe1-xYxO3-y polycrystals as a function of yttrium content (x = 0.05, 0.1, 0.15, and 0.2) was conducted i n controlled oxygen partial pressures of 0.1-2 X 10(4) Pa at 1200-1400 degr ees C to determine deformation kinetics and the rate-controlling species fo r diffusional creep. Creep rate was independent of oxygen partial pressure and the steady-state creep rate increased with increasing Y content. The re sults can be explained on the basis of a grain-boundary-sliding creep mecha nism in which the rate-controlling species are Ba or Ce interstitials. A si mple point-defect model was used to describe the results. (C) 1999 Elsevier Science B.V. All rights reserved.