CONDUCTIVITY AND CREEP IN ACCEPTOR-DOMINATED POLYCRYSTALLINE AL2O3

Ionic and electronic conductivity and compressive creep of hot-pressed polycrystalline acceptor-dominated Al2O3 were measured as a function of oxygen partial pressure and grain size varying from 3 to 200 μm. Hole conduction shows a slight preference for grainboundaries; ionic conduction is slightly hindered by grain boundaries, indicating that fast oxygen grain-boundary diffusion involving charged species does not occur. Conductivity and creep are accounted for on the basis of a model in which there is fast grain-boundary migration by a neutral oxygen species. © 1979 Chapman and Hall Ltd.