Reduced dimensional ferroelectric domains and their characterization techniques

Abstract

Ferroelectricity is one of the most major physical phenomena in electronic devices due to its sustainable polarity in the absence of an external electric field and its switchability in response to external stimuli. In alignment with the industry trend towards increasingly integrated devices, research into smaller-sized ferroelectric materials becomes indispensable. In the pursuit of achieving the pinnacle of device miniaturization, recent studies have unveiled materials exhibiting sub-nanometric, unit cell-level domains. Concurrently, advances in transmission electron microscopy-based structural characterization techniques have been made, enabling in-depth analysis of the intricate properties of these miniaturized ferroelectric materials. This review highlights the structural mechanism of ferroelectricity in a reduced scale, as well as the recent advancements in electron microscopy techniques for characterizing miniaturized ferroelectric domains, particularly in the fields of in-situ biasing and atomic scale imaging. We believe that this work will provide structural insights for engineering and characterizing ferroelectrics for the design of downsized high-density memory devices at the quantum limit.