Tilt-driven ferrielectricity in PbZrO
arXiv:2607.27752
The paper demonstrates that adding an octahedral tilt to the antiferroelectric PbZrO₃ structure breaks symmetry and creates a ferrielectric polar phase, confirmed by first‑principles calculations and atomic‑scale imaging.
Abstract
We reveal a tilt-driven mechanism for ferrielectricity in prototypical antiferroelectric PbZrO. Specifically, introducing an additional octahedral tilt into the antiferroelectric phase breaks the symmetry constraint that enforces equal antiparallel dipoles, converting the compensated ``'' nonpolar configuration into an uncompensated ``'' polar phase. First-principles calculations show that the phase becomes stabilized under lattice contraction and gains increasing free-energy advantage over competing phases at finite temperatures. Atomic-scale imaging directly confirms the presence of -like structures in thin films and single crystals. This work identifies a symmetry-governed, kinetically easily accessible pathway to ferrielectricity and establishes a form of ``competitive'' improper ferroelectricity, with broad implications for antiferroelectrics.