Characterization of domain structure in BaTiO3 based ceramics by scanning electron microscopy

The domain structure and domain configuration in pure and modified BaTiO3 ceramics compacts sintered at various temperatures have been investigated using SEM technique. According to the topographical contrast at domain boundaries it has been shown that the single domain and the banded domain structure, depending on the type of BaTiO3 and on the grain size, are present only in grains greater than 1 mu m. The single domain structure is the main characteristic of modified barium titanate, while the banded domain structure prevails in pure barium titanate. The number of bands per grain depends on the grain size, but their size, shape and orientation vary from grain to grain. Mainly 90 degrees domains walls are present in both types of ceramics and the herringbone and square net pattern are the most common configurations in unmodified BaTiO3. The wall thickness ranged from 0,05 mu m to 0,15 mu m, while the domain width is in the range of 0,2 mu m to 1,2 mu m, indicating the decrease of domain width in ceramics with additives compared to that one in pure BaTiO3.