Effect of grain size on diffusion-induced grain-boundary migration in Ba(Zn1/3Nb2/3)O-3 ceramics

Diffusion-induced grain-boundary migration (DIGM) in Ba(Zn1/3Nb2/3)O-3 (BZN) ceramics was investigated with small (3.0 mu m) and large (31.4 mu m) grain size specimens. The specimens were embedded in Nb2O5 or ZnO powders and then heat-treated at 1250 degrees and 1310 degrees C, respectively, The grain boundaries of the small grain size specimens were immobile, while those of the large grain size specimens migrated away from their centers of curvature. From the observed difference in migration behavior depending on grain size, the magnitude of the driving force for the DIGM was estimated.