Jonathan E Spanier

This data package contains the data used in the derivation of the strain-temperature phase diagrams of epitaxial barium strontium titanate solid solutions. The data contains the description of the phase boundaries across multiple chemical compositions of the solid solution. The package also includes the ferroelectric equilibrium states (polarization, domain wall orientation, domain volume fractions) as a function of the biaxial epitaxial misfit strain, temperature, chemical composition of the solid solution. The equilibrium states are provided for the single-domain and polydomain/heterophase configurations of the material. The equilibrium states are used in the definition of the phase diagrams and the corresponding phase boundaries included in the dataset.

This dataset contains raw and processed experimental data supporting the
study “Strain-induced lead-free morphotropic phase boundary.” Data were
collected from NaNbO₃ thin films of varying thicknesses using techniques
such as reciprocal space mapping (RSM), high-resolution X-ray diffraction
(HRXRD), atomic force microscopy (AFM), piezoresponse force microscopy
(PFM), scanning transmission electron microscopy (STEM), X-ray
photoelectron spectroscopy (XPS), dielectric spectroscopy, and
ferroelectric measurements. Files are organized by sample ID, with
filenames indicating technique, sample thickness, date, and format. Data
formats include .csv for tabular values, .ibw for Igor Pro binary
waveforms, .pvsm and .vti for ParaView visualization states, .xrdml for
XRD raw data, and image formats (.png, .PNG). These files can be reused to
replicate the analyses presented in the associated article, enable
independent phase and domain structure studies, and support the
development of phase boundary engineering strategies in lead-free
ferroelectric thin films. The dataset is released under the Creative
Commons Zero (CC0) license and contains no personal or sensitive
information.

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.