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.
Topology optimized design of functionally graded piezoelectric ultrasonic transducers
