Correlation between microstructure, strain behavior, and acoustic emissionof soft PZT ceramics

The influence of grain size and domain configuration on the microscopic and macroscopic electromechanical properties of soft lead zirconate titanate ( PZT) ceramics were studied. Fine- and coarse-grained PZT ceramics with an a verage grain size of 1.5 and 3.5 mum were prepared using the conventional m ixed oxide route and different sintering, conditions (1225 degreesC/2 h and 1300 degreesC/10 h). The experiments were performed on PZT with different Zr/Ti-ratios in order to obtain pure tetragonal (45/55), pure rhombohedral (60/40), and morphotropic (54/46) compositions. To distinguish between the intrinsic and extrinsic effect microscopic strain measurements (Synchrotron X-ray diffraction) were compared with macroscopic measurements of the mech anical hysteresis loop. The results were correlated with acoustic emission measurements which microscopically reflected the intrinsic and extrinsic co ntributions to the macroscopic strain of the different crystallographic mod ifications. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd . All rights reserved.