Diffusion induced grain-boundary migration was observed when 4 and 9 mol% SrO-doped CeO2 (SrDC) ceramics were heat-treated at 1300C after sintering at 1600C. In the 9mol% SrO-doped CeO2 specimen, the curvature and distance of boundary migration were increased significantly as the heat-treatment time was increased from 10 min to 10 h at 1300C. This induced a ~ 2.9-fold increase of the apparent grain-boundary resistivity, which was explained by the physico-chemical change of the grain-boundary structure and/or the current constriction effect due to the undulated boundary morphology.

Diffusion Induced Grain-Boundary Migration in SrO-Doped CeO2 Electrolyte and Its Effect on Electrical Properties. P.S.Cho, S.Y.Park, J.J.Kim, H.S.Do, H.M.Park, J.H.Lee: Solid State Ionics, 2010, 181[31-32], 1420-4