Octahedral tilt-suppression of ferroelectric domain wall dynamics and the associated piezoelectric activity in Pb(Zr,Ti)O3

The R3m-R3c transition is in a limited phase field in the Pb(Zr1-x,Ti-x)O-3 (PZT) phase diagram and is a ferroelectric-ferroelectric phase transition that involves the coupling of a secondary displacive ferroelastic phase transition, associated with a structural rotation of the octahedra about the polar threefold axis. Through systematic temperature-dependent piezoelectric characterization under resonance conditions and high-field unipolar ac drive the influence of the aforementioned transition on piezoelectric and electromechanical properties is noted for two compositions x=0.30 and x=0.40 mol fraction lead titanate. Applying Rayleigh law analysis to access the relative extrinsic domain wall contributions to the nonlinear permittivity and converse piezoelectric properties, we observe significant differences in the nonlinear response between the R3m and R3c phases and note a discontinuity at the transition for both PZT compositions. A complementary study was conducted through diffraction contrast transmission electron microscopy to access structure property relations. Diffraction contrast imaging reveals that antiphase boundaries (APB's) associated with octahedral tilt may coincide with non-180 degrees ferroelectric domain walls. This microstructural evidence suggests that APB's suppress the motion of non-180 degrees ferroelectric domain walls, leading to reduced extrinsic contributions to the piezoelectric and dielectric response in the low-temperature phase (R3c). The implications of these observations are discussed in relation to both the PZT system and other perovskite-based systems such as BiMO3-PbTiO3 systems.