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

Abstract

In the present paper the microstructure and domain structure in modified BaTiO3 with Pb and Ca as additives have been investigated using SEM technique. 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 acts as gl ain growth inhibitor. The domain configuration is almost the same. The small grain microstructure with tiny domains have been observed in specimen sintered at 1300 degrees C and the average grain size is in the range 1-3 mu m. For those specimens sintered at 1320 degrees C the homogenous microstructure is also obtained with grain size around 2-4 mu m. For both types of specimens, the single domain structure is associated with grain which size is lower than 2 mu m. The banded domain structure could be observed in grains with size bigger than 3 mu m. The bar shape grains and elongated grains together with some large region in microstructure are free of domain structure. The observed domain patterns reveal mainly the straight domain boundary lines with 90 degrees domains walls. The wall thickness ranged from 0.03 mu m to 0.15 mu m, while the domain width is in the range of 0.1 mu m-1 mu m.