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 ..., Four-dimensional scanning transmission electron microscopy datasets are collected with EMPAD (.raw, .xml). Mutlislice electron ptychography reconstructions (.mat) are performed with the foldslice package (https://github.com/yijiang1/fold_slice)(opens in new window) that is built upon the Matlab code developed by the Science IT and the coherent X-ray scattering (CXS) groups at Paul Scherrer Institut, Switzerland: https://www.psi.ch/en/sls/csaxs/software(opens in new window). , , # Insights into Chemical and Structural Order at Planar Defects in Pb2(MgW)O6 Using Multislice Electron Ptychography

[https://doi.org/10.5061/dryad.hmgqnk9tt](https://doi.org/10.5061/dryad.hmgqnk9tt)

## Description of the data and file structure

Four-dimensional scanning transmission electron microscopy dataset and metadata collected with EMPAD (.raw, .xml). The `.raw` file contains a 4D-STEM dataset that can be viewed using tools such as the [4D-STEM Explorer app for macOS](https://apps.apple.com/us/app/4d-stem-explorer/id1332413091?mt=12), [empad2 package](https://github.com/sezelt/empad2), Fiji plugins, or custom Python scripts. The `.xml` file contains metadata for the collection of the `.raw` file and can be accessed with text edit tools.

Multislice electron ptychography reconstruction outputs, including the probe, object, and engine parameters are included in the `.mat` file following the stand output format of [fold_slice]([https://github.com/yijiang1/fold_slice](https://gith...,