|About this Abstract
|MS&T21: Materials Science & Technology
|Probing Defect Properties and Behavior under Mechanical Deformation and Extreme Conditions
|Now On-Demand Only - Imaging Electronic Properties of Ferroelectric Interfaces and Domain Walls via 4D STEM
|Christopher Addiego, Huaixun Huyan, Xiaoqing Pan
|On-Site Speaker (Planned)
Defects and other features that break translational symmetry, such as interfaces, grain boundaries, and domain walls, in crystalline materials are key factors in determining overall properties and can also lead to unique structures with deliberate engineering. Although advances in scanning transmission electron microscopy (STEM) have made determining the structure and composition of these features routine, determining the electronic properties remains challenging. Four-dimensional STEM (4D-STEM) offers one avenue for revealing the charge distribution of localized atomic-scale features without the computational cost associated with previous experimental methods or first-principles calculations. Here, we will discuss the applications of 4D STEM to studying the electric field and charge distribution in ferroelectric interfaces and domain walls. In BiFeO3, we find evidence of charge separation in both an interface with insulating SrTiO3 and at 109° domain walls through two different mechanisms. Applications to PbTiO3 interfaces and superlattices will also be discussed.