Domain Observation for BaTiO3 Ceramics by a Combination of Chemical Etching and Electron Backscattered Diffraction

Abstract

The domain structures in BaTiO3 ceramics were characterized by a combination of chemical etching and electron backscattered diffraction (EBSD). For a grain in a nonpoled BaTiO3 ceramic, an intergrowth of (101)/(110)-oriented crystals, which involves 90° domain structures, was clearly observed by EBSD. The lamellar (101)/(110)-oriented crystals in the grain aligned perpendicularly to the in-plane [111]/[111] at 1 µm intervals. The direction of spontaneous polarization (Ps) in the (101)-oriented crystals was evaluated by HCl etching that proceeded sensitively in the polarization direction. As a result, it was found that the direction of Ps in the (101)-oriented parts is upward by 45° from the surface. After poling treatment, a (101)/(110)-oriented grain predominantly containing (101)-oriented crystals was found. The negatively charged (101)-oriented region was etched slowly, compared with the (110)-oriented region.