Functionally graded piezoelectric ceramics (FGM) plates are attractive due to their ability to
broaden the frequency bandwidth of the ultrasonic transducers. A resistivity gradient La-doped Lead
Zirconate Titanate/Al-doped Zinc Oxide (La-PZT/Al-ZnO) piezoelectric ceramics plate was developed
using a powder metallurgical process. Grading of the piezoelectric modulus across the plate was
experimentally confirmed by the electrical impedance analysis and its gradient distribution was
characterized using the profile-technique. The distribution of Zn2+ ions in the PZT region was examined
using EPMA, XRD and SEM/EDX, respectively. Analysis results show that the gradient distributions of
structural and electrical properties inside the FGM plate are mainly caused by the diffusion and
aggregation of Zn2+ ions in the PZT layer. The functionally graded piezoelectric ceramics plate presented
here will be useful for broadening the frequency bandwidth of piezoelectric transducers.