Effects of Zirconia on Microstructure and Dielectric Properties of Barium Titanate Ceramics

Abstract

Dielectric properties and structural characteristics of BaTiO 3 ceramics are significantly influenced by small addition (2 wt%) of ZrO 2 . SEM and TEM observations revealed enhanced microstructural uniformity and retarded grain growth depending on sintering temperature. Above 1320°C, Zr diffusion into the BaTiO 3 lattice resulted in a chemical modification of the tetragonal structure and the development of core–shell grains. Below 1320°C, TEM analysis showed ZrO 2 at the grain boundaries as discrete particles (∼0.03μm). X‐ray diffraction analysis revealed a decrease in the axial (c/a) ratio with decreasing grain size. A corresponding decrease in the spontaneous polarization, and twinned domain structures, were also observed in the fine‐grained ceramics. These samples also showed a flattened permittivity response with temperature and significantly lower losses.