A new grain core-grain shell structure in ferro-nonferroelectric ceramics

The grain-core-grain-shell structure, a two-phase grain structure that consists of a ferroelectric core and a nonferroelectric shell, is discussed. Electron microscopy after a temperature change of barium-titanate-calcium-stannate samples exhibiting this structure shows that the ferroelectric domain structure disappears during the phase transition. This is taken as direct proof that the grain-core-grain shell structure is a complex, two-phase, ferroelectric-nonferroelectric structure. >