  Antiferroelectric perovskite oxides exhibit exceptional dielectric properties
and high structural/chemical tunability, making them promising for a wide range
of applications from high energy-density capacitors to solid-state cooling.
However, tailoring the antiferroelectric phase stability through alloying is
hampered by the complex interplay between chemistry and the alignment of dipole
moments. In this study, correlations between chemical order and the stability
of the antiferroelectric phase are established at anti-phase boundaries in
\ce{Pb2MgWO6}. Using multislice ptychography, we reveal the three-dimensional
nature of chemical order at the boundaries and show that they exhibit a finite
width of chemical intermixing. Furthermore, regions at and adjacent to the
anti-phase boundary exhibit antiferroelectric displacements in contrast to the
overall paraelectric film. Combining spatial statistics and density functional
theory simulations, local antiferroelectric distortions are shown to be
confined to and stabilized by chemical disorder. Enabled by the
three-dimensional information of multislice ptychography, these results provide
insights into the interplay between chemical order and electronic properties to
engineer antiferroelectric material response.
