Anisotropy in Polarized Barium Titanate Ceramics

Dielectric constants ε 1 T and ε 3 T (perpendicular and parallel to the direction of the polarization) and elastic compliance coefficients s 11 E , s 33 E and s 44 E of fully prepolarized BaTiO 3 ceramics are measured, and are compared with the dielectric constant ε 0 and the elastic compliance coefficients s 11 0 and s 44 0 of the unpolarized ceramics. Anisotropy is small (a few percent). By semi-quantitative calculations, it is shown that the 180°-reversals of domains mainly remain after the poling process, and that anisotropy is due to the piezoelectric interactions among single crystals which constitute the ceramic.