Topological polar solitons such as domain walls, vortices, and polar skyrmions in ferroelectrics and related heterostructures have attracted increasing attention owing to their unique functionalities and potential applications in electronic devices. Recent advances in transmission electron microscopy (TEM) enable us to study the atomic structure, composition, properties, and dynamic behaviors of materials and nanostructures at the atomic scale. In this talk, I will show how ferroelectric domains nucleate and evolve under applied field in TEM. The polarization of nanodomains, vortices and other polar solitons can be imaged with atomic resolution. With the novel four-dimensional scanning TEM diffraction imaging (4D STEM) method developed recently, we are able to measure charge density, dipole moment, valence electron distribution in nanocrystals such as topological polar solitons, or at interfaces and single defects with sub-angstrom resolution.
The seminar will be chaired by Jirka Hlinka, Department of Dielectrics.