Characterization of domain configurations in LiTaO3/Al2O3 ceramic composites

Characterization of domain configurations in 15 vol% LiTaO3/Al2O3 ceramic composites hot-pressed sintered at 1300 deg. C was carried out using transmission electron microscopy and high-resolution transmission electron microscopy. Mainly banded- and wedge-shaped 90 deg. domains, with few 180o domains, were formed in the LiTaO3 grains within the composite. The formation of 90o domains was attributed to the large stress caused by residual polarization. Many dark dots, distributed along the 90 deg. domain boundaries, were detected and it was confirmed that they were not a deposited second phase but a type of contrast induced by high strain. The 90 deg. domain boundaries presented an α-type fringe contrast and no δ-type fringes were observed, indicating that they were of the non-conventional type.