Ferroelectric oxides PbZr1-xTixO3 (PZT) with the ABO3 perovskite structure exhibit exceptional polarization responses near their morphotropic phase boundary (MPB), yet the chemical origin of this behavior remains unclear. Here, we show that, in a prototypical composition, 0.05Pb(Mn1/3Sb2/3)O3-0.95PbZr0.52Ti0.48O3, this origin arises from coupled effects of B-site chemical ordering and multi-ion displacement heterogeneity-related disordering. Pronounced anti-self-clustering of Zr and Ti forms a short-range chemical ordering driven by the mismatch between ionic Zr-O and more covalent Ti-O bonds, generating a soft-hard compatible BO6 network that reduces local stress, which facilitates polarization rotation and switching. Simultaneously, A-site, B-site, and oxygen ions display significant, directionally distinct off-center displacements, producing continuous local monoclinic polar states (MA-MB) with coplanar polarization vectors and nanoscale domains with mobile walls. These results show that PZT's extraordinary response emerges from a unity-of-opposites relationship that balances rigidity and flexibility through compatible bonding and multi-ion displacements, offering guidance for designing high-performance ferroelectrics.
Yue et al. (2026) studied this question.