Investigating Ferroelectric Domain and Domain Wall Dynamics at Atomic Resolution by TEM/STEM in situ Heating and Biasing

Abstract

Conducting domain walls (DWs) in ferroelectrics is an emerging research focus in nano-electronics [1,2]. Previously overlooked, these walls have recently been reported to possess diverse functional characteristics that are completely different from the domains that they delineate [3][4][5]. They can have their own distinct chemistry and magnetic behavior [6], and in turn represent a completely new sheet phase. The characteristics of these confined regions are believed to have the same exotic functional behaviours as seen in 2D materials such as graphene, opening up a plethora of possible electronic applications. In addition, the walls have the unique property of being 'agile'; they can be created or destroyed and even be controllably moved by an external field. However, this is an area of research at its very early stages, with a great deal of the fundamental physics still unknown. Since the region of interest (the domain wall) is atomically thin and dynamic, it is essential for the physical characterization to be at this scale and be time-resolved.

Nanoscale Surface Structure of Nanometer-Thick Ferroelectric BaTiO3 Films Revealed by Synchrotron X-ray Scanning Tunneling Microscopy: Implications for Catalytic Adsorption Reactions

“…Another drawback in implementing independent techniques to investigate ferroelectric effects on the surfaces, especially as it relates to catalysis, is establishing the identical polarization state on the surface for a reliable comparison of the results across different experiments, highlighting the importance of in situ polarization switching . Among recent efforts in addressing this issue, only cross-sectional transmission electron microscopy (TEM) − and scanning TEM (STEM) − with in situ biasing have been shown to be capable of providing an in-depth understanding of the surface structure and chemical shifts with atomic resolution.…”