Reorientation of Defect Dipoles in Ferroelectric Ceramics
LI Bao-Shan, LI Guo-Rong, ZHAO Su-Chuan, ZHU Zhi-Gang, DING Ai-Li
The State Key Laboratory of High Performance Ceramics and Superfine-Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050
Reorientation of Defect Dipoles in Ferroelectric Ceramics
LI Bao-Shan;LI Guo-Rong;ZHAO Su-Chuan;ZHU Zhi-Gang;DING Ai-Li
The State Key Laboratory of High Performance Ceramics and Superfine-Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050
Abstract： We investigate the frequency, temperature, tetragonality and quenched temperature dependences of the hysteresis loops in Pb[(Zr0.52Ti0.48)0.95(Mn1/3Nb2/3)0.05]O3 (PMnN-PZT) ceramics. It has been demonstrated that the polarization-field hysteresis curves show ``pinched'' shapes when tested at room temperature, higher frequency or using the large-tetragonality specimen. While normal square-like loops are observed at 200°C and 0.01Hz or using the small-tetragonality one. Meanwhile, close relations between the P-E loops and the applied frequency, temperature or tetragonality reveal that there exists a typical relaxation time corresponding to the reorientation of the defect dipoles. It can be seen further from the quenched temperature dependences of the loops that the reorientation of the defect dipoles may influence the pinching. Compared to the intrinsic depinning procedure induced by changes of the distribution of defect dipoles, we provide new evidence for extrinsic depinning mechanism of the defect dipoles in the ferroelectric ceramics.
2005, Vol. 22 
