Observation of ferroelectric domain boundaries in BaTiO3by transmission and reflection electron microscopy

Abstract

Abstract The strain fields in the vicinity of 90° domain boundaries in BaTiO3 ceramics and single crystals have been revealed by high resolution images and diffractograms. It is suggested that such strain fields may be relaxed in the thin ferroelectric films. The observation of 180° domain boundaries in bright field imaging is possible provided that the contrast due to the failure of Friedel's law is large enough. Reflection electron microscopy (REM) has been developed as a novel technique to study the domain boundaries in ferroelectrics. The contrasts of various ferroelectric domain boundaries are discussed. It is found that the contrast of 90° domain boundaries can arise from the differences of deviations from the Bragg condition, including those due to the lattice distortion around the domain boundaries. The contrast can be enhanced by surface resonance conditions.