Title: Observation of Atomic-Scale Polar Vortex−Antivortex Pairs inAntiferroelectric PbZrO3 Thin Films

Authors: XianKui Wei*#, Ke Xu#, Kaushik Vaideeswaran, Joachim Mayer, Houbing Huang*

Abstract: Topological polar structures, in analogy to spin vortices andskyrmions, have received tremendous attention for their fascinating prospectsin future device applications. However, in the widely studied ferroelectric-based superlattices, the epitaxial heterointerfaces, yielding desired strain,depolarization, and gradient energies, greatly confine the mobility of thetopological solitons. Here, we report observation of polar vortex−antivortexpairs near junctions of antiphase boundaries in antiferroelectric PbZrO3 thinfilms by using atomic-resolution scanning transmission electron microscopy.Our temporal-resolved lattice analysis reveals that the local strain gradientcaused by an incommensurate modulation constructs the smallest topologicalunits reported to date. Our phase-field simulations unveil that the Pb−O vacancy-induced random electric fields account for theirthree-dimensional formation, and the stimulus of electron-beam irradiation can drive their dynamic migration. The findings offer anew approach to comprehend fundamental physics about antiferroelectricity and the design of functional devices based ontopological structures in antiferroelectric thin films

Full-Link: https://pubs.acs.org/doi/10.1021/acs.nanolett.5c01506