Abstract: The reduction behavior of PZN-PZT piezoelectric ceramics was preliminary studied for developing of the so called RAINBOW device
with ultrahigh induced displacement based on this material. Multilayer microstructure was observed in the cross section of reduced samples.
Fracture morphology, phase constitution and electric conductive type of every layer were studied with the help of SEM, XRD and electric
conductivity measuring methods. An explanation of the reduction process and mechanism of PZN-PZT ceramic reduced by graphite under high temperature
was proposed. It was believed that the reduction first happens at grain bourndary, then at the inner part of grains. With the increasing of
reduction extent, the variation of electric conductive types of different layers follows the sequence of insulator,semiconductor and metal. XRD
results showed that the original crystal stucture of PZN-PZT solid solution retains in the layers with lower level reduction, while it is completely
destroyed in highly reduced layers.

Key words: RAINBOW, piezoelectric actuator, reduction behavior