Compression of piezoelectric ceramic at constant electric field:: Energy absorption through non-180° domain-wall motion

The effect of bias electric field on the nonlinear stress-strain response of a lead zirconate-lead titanate piezoelectric ceramic is studied. The material is subjected to various compressive stress amplitudes (25-300 MPa) under constant electric field (from -0.5 to 2.0 MV/m) along the original poling direction. Application of a positive electric-field bias results in closed stress-strain hysteresis loops absorbing significant amounts of mechanical energy. Increasing the positive electric field increases the specific damping and decreases the elastic modulus. The trend is reversed when the electric field becomes sufficiently high to inhibit the domain-wall motion by the mechanical stresses. Measured specific damping values vary from 0.18 to 0.46 depending on the stress amplitude and bias electric field. The corresponding secant modulus varies from 79 to 24 GPa. The coercive stress is found to approach zero as the negative electric-field bias approaches the coercive field value. The coercive stress increases with increasing positive electric field as expected from the balance of mechanical and electrical energies. The physics of the observed phenomena is explained in terms of non-180degrees domain-wall motion. (C) 2002 American Institute of Physics.