Optimization of poling process for piezoelectric PZT ceramics

The properties of piezoelectric ceramics are dependent on the poling conditions. To describe the optimal poling conditions, the threshold voltage, V_th, and T_th, required to achieve 90% of maximum K_p (planar coupling factor) value are defined. In the case of (Pb_1-xSr _x) [(Zr_0.52Ti_0.48)_0.975Nb _0.025]O₃ ceramics, decreases of both V _th and T_th with increasing x value are found. These can be related to variations of polarization and coercive field and finally to the variation of domain rotation. A selection rule for the optimal poling conditions based on this hypothesis is derived