Effects of grain boundary on dielectric properties in fine-grained BaTiO3 ceramics

BaTiO3 dielectric ceramics, which have no core-shell structure, were prepared. High-resolution transmission electron microscope (TEM) and the newly developed chemical etching analysis revealed the composition of the grain boundary. The grain boundary has an important role in stabilizing temperature dependence of a dielectric constant. The grain boundary causes a large stress against grains, resulting in a change of the domain structure. So, the stress from the grain boundary is considered to depress the dielectric abnormality at the Curie temperature.