SEM investigation of domain structure in (Ba, Ca, Pb)TiO3

The microstructure and domain structure in BaTiO3 modified with Pb and Ca additives was studied by SEM. The (Ba,Pb)TiO3 and (Ba,Ca,Pb)TiO3 ceramics show a slight difference in grain size, being smaller in composites with Ca additives, which act as a grain growth inhibitor. The domain configuration is almost the same. A fine grain structure with tiny domains was observed in a specimen sintered at 1300 C, and the average grain size is in the range 1-3 micron. For those specimens sintered at 1320 C, a homogeneous structure is also obtained with a grain size around 2-4 micron. For both types of specimens, the single domain structure is associated with a grain size lower than 2 micron. The banded domain structure could be observed in grains with sizes larger than 3 micron. The rod-shaped grains and elongated grains, together with some larger regions in the microstructure, are free of the domain structure. The observed domain patterns mainly reveal straight domain boundary lines with 90 degree domain walls. The wall thickness ranged from 0.03 to 0.15 micron, while the domain width is in the range of 0.1-1 micron. 6 refs.