Mechanism of resistivity gradient in monolithic PZT ceramics

The interdiffusion of Fe3+ and La3+ doping ions in the PZT perovskites was examined. The distribution of doping ions, crystal structures and microstructures was characterized by using Electron Probe Microbeam Analysis (EPMA), X-ray diffractormeter (XRD) and Optical Microscope (OM), respectively. The diffusion behavior of doping ions was quantitatively investigated by using Fick’ second law and qualitatively examined from the viewpoint of ion transfer. The forming mechanism of the resistivity and piezoelectric property gradients was investigated. It was verified that the interdiffusion of La3+ and Fe3+ ions occurs via vacancy mechanism on the A-site and B-site in the PZT perovskite structure, respectively.