Uniaxial Stress Dependence and Scaling Behavior of Dynamic Hysteresis Responses in Soft PZT Ceramics

The ferroelectric properties under uniaxial compressive pre-stress and scaling behavior of commercial soft PZT ceramics are investigated. The ferroelectric properties under the uniaxial compressive pre-stress of the ceramics are observed at stress up to 24 MPa using a compressometer in conjunction with a modified Sawyer-Tower circuit. The results show that the ferroelectric characteristics, i.e. the area of the ferroelectric hysteresis (P-E) loops, the saturation polarization (P_sat), the remanent polarization (P_r), and the loop squareness (R_sq) decrease with increasing compressive pre-stress, while the coercive field (E_c) is virtually unaffected by the applied stress. The stress-induced domain wall motion suppression and non-180deg ferroelectic domain switching processes are responsible for the changes observed. In addition, a significant decrease in those parameters after a full cycle of stress application has been observed and attributed to the stress induced decrease in switchable part of spontaneous polarization at high stress. Finally, the dynamic behavior of the ferroelectric properties is also examined to establish the scaling behavior of the soft PZT ceramics. It has been found that the scaling behavior found for the bulk ceramic differs slightly from the theoretical prediction and that obtained from the experimental investigation on thin-film.