Residual stress relief due to fatigue in tetragonal lead zirconate titanate ceramics

High energy synchrotron XRD was employed to determine the lattice strain ε{111} and diffraction peak intensity ratio R{200} in tetragonal PZT ceramics, both in the virgin poled state and after a bipolar fatigue experiment. It was shown that the occurrence of microstructural damage during fatigue was accompanied by a reduction in the gradient of the ε{111}-cos ψ plot, indicating a reduction in the level of residual stress due to poling. In contrast, the fraction of oriented 90°ferroelectric domains, quantified in terms of R{200}, was not affected significantly by fatigue. The change in residual stress due to fatigue is interpreted in terms of a change in the average elastic stiffness of the polycrystalline matrix due to the presence of inter-granular microcracks.