Correlation between microstructure,strain behavior,and acoustic emission of 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 average grain size of 1.5 and 3.5 μm were prepared using the conventional mixed oxide route and different sintering conditions (1225°C/2 h and 1300°C/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 mechanical hysteresis loop. The results were correlated with acoustic emission measurements which microscopically reflected the intrinsic and extrinsic contributions to the macroscopic strain of the different crystallographic modifications.