Structural Correlation to Piezoelectric and Ferroelectric Mechanisms in Rhombohedral Pb(Zr,Ti)O3 Ceramics by in-Situ Synchrotron Diffraction.

The evidence of fundamental lattice strain and domain switching contribution to the piezoelectric and ferroelectric responses of ceramics has been well studied, while the contribution from crystal structure variation has been rarely reported in terms of the existence of intergranular stress/strain and crystallographic texture. In the present study, the detailed electric field induced structure evolution in rhombohedral PbZr0.55Ti0.45O3 (PZT55) has been investigated by in-situ high-energy synchrotron diffraction. The phase of PZT55 is stable in the rhombohedral one against bipolar electrical loading. It is interesting to find that both spontaneous polarization and unit cell volume exhibit a butterfly shape in response to electric field. Direct evidence has revealed that the lattice strain and volume expansion show similar variation tendency to the piezoelectric response in the rhombohedral PZT55. The macro-polarization of PZT55 derives from the combination of domain switching and spontaneous polarization change.