Data from: Insights into chemical and structural order at planar defects in Pb2(MgW)O6 using multislice electron ptychography

Switchable order parameters in ferroic materials are essential for
functional electronic devices, yet disruptions of the ordering can take
the form of planar boundaries or defects that exhibit distinct
properties from the bulk, such as electrical (polar) or magnetic
(spin) response. Characterizing the structure of these boundaries is
challenging due to their confined size and three-dimensional nature. Here,
a chemical anti-phase boundary in the highly ordered double perovskite
Pb2MgWO6 is investigated using multislice electron ptychography.
The boundary is revealed to be inclined along the electron beam direction
with a finite width of chemical intermixing. Additionally, regions at and
near the boundary exhibit antiferroelectric-like displacements,
contrasting with the predominantly paraelectric matrix. Spatial statistics
and density functional theory calculations further indicate that despite
their higher energy, chemical anti-phase boundaries form due to kinetic
constraints during growth, with extended antiferroelectric-like
distortions induced by the chemically frustrated environment in the
proximity of the boundary. The three-dimensional imaging provides critical
insights into the interplay between local chemistry and the polar
environment, elucidating the role of anti-phase boundaries and their
associated confined structural distortions and offering new opportunities
for engineering ferroic thin films.