HIGHLY ANISOTROPIC ELECTROMECHANICAL PROPERTIES IN MODIFIED LEAD-TITANATE CERAMICS.

摘要

The dielectric, elastic and piezoelectric properties of modified lead titanate ceramics were investigated with the goal of better understanding their highly anisotropic electromechanical behavior.;Measurements of the complex material coefficients relevant for the planar coupling mode showed that piezoelectric coefficient d;A significant imaginary component of the piezoelectric coefficient and a similar temperature behavior of imaginary elastic, dielectric and piezoelectric coefficients in these ceramics indicate a presence of piezoelectric relaxational mechanisms whose origin is in a coupling between dielectric and elastic loss mechanisms. Assuming that the complex d;A large anisotropy in piezoelectric coefficients seems to be only enhanced by zero d;Two compositions, (Pb;The equivalent circuit of a resonator with a large piezoelectric phase angle is derived.