Measurement of cationic diffusivity through Er2O3/Y2O3 interdiffusion under AC-flash event

The diffusivity of Er cations in Y 2 O 3 was directly investigated using Er 2 O 3 /Y 2 O 3 interdiffusion couples under alternating current (AC) flash events. Specimen temperatures during the AC-flash events were determined by a combination of direct thermographic measurement and numerical simulations. Compared to conventional heat treatment without electric field, the diffusion of the Er cations proceeded more than 30 times faster in the AC-flash treatment at a specimen temperature of about 1700℃. This indicates that the cationic interdiffusion was athermally promoted by the AC electric field. Eventually, both the lattice and grain boundary diffusivities were 2–3 orders of magnitude greater under the AC-flash events than without the electric field at the specimen temperatures of 1550℃–1880℃. Grain growth and grain boundary migration associated with significant grain boundary bowing-out were also enhanced with the increasing current density.