Aberration corrected STEM techniques to investigate polarization in ferroelectric domain walls and vortices

Ferroelectric domain wall (DW) based nano-electronics is an emerging new field of research. It is only recently with advancements in electron and atomic force microscopy instrumentation that the complex nature of these 2D entities can be probed. In this Research Update, the advances in aberration corrected scanning transmission electron microscopy applied to ferroelectric topological defects are summarized. We discuss sub-atomic imaging and diffraction techniques used to observe changes in polarization, chemical composition, charge density, and strain at DWs and vortices. We further highlight the current achievements in mapping the 3D nature of ferroelectric polar skyrmions and in situ biasing. This Review will focus on both the fundamental physics of DW and polar vortex formation and their dynamics. Finally, we discuss how electron spectroscopy can be used to relate the quantified structural distortions of polar topological entities to changes in their oxidation state and band structure.

Automated summary

Advancements in electron microscopy have allowed for the exploration of the complex nature of ferroelectric topological defects, observing changes in polarization, chemical composition, charge density, and strain. Current achievements include mapping the 3D nature of ferroelectric polar skyrmions and in situ biasing. The research focuses on understanding the fundamental physics and dynamics of domain wall and polar vortex formation in ferroelectrics.