Interferometric 4D-STEM for Lattice Distortion and Interlayer Spacing Measurements of Bilayer and Trilayer 2D Materials

Author(s)
Michael J. Zachman, Jacob Madsen, Xiang Zhang, Pulickel M. Ajayan, Toma Susi, Miaofang Chi
Abstract

Van der Waals materials composed of stacks of individual atomic layers have attracted considerable attention due to their exotic electronic properties that can be altered by, e.g., manipulating the twist angle of bilayer materials or the stacking sequence of trilayer materials. To fully understand and control the unique properties of these few-layer materials, a technique that can provide information about their local in-plane structural deformations, twist direction, and out-of-plane structure is needed. In principle, interference in overlap regions of Bragg disks originating from separate layers of a material encodes 3D information about the relative positions of atoms in the corresponding layers. Here, an interferometric 4D scanning transmission electron microscopy technique is described that utilizes this phenomenon to extract precise structural information from few-layer materials with nm-scale resolution. It is demonstrated how this technique enables measurement of local pm-scale in-plane lattice distortions as well as twist direction and average interlayer spacings in bilayer and trilayer graphene, and therefore provides a means to better understand the interplay between electronic properties and precise structural arrangements of few-layer 2D materials.

Organisation(s)
Physics of Nanostructured Materials
External organisation(s)
Rice University, Oak Ridge National Laboratory
Journal
Small
Volume
17
No. of pages
10
ISSN
1613-6810
Publication date
06-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
210004 Nanomaterials, 103042 Electron microscopy, 102009 Computer simulation, 103018 Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/interferometric-4dstem-for-lattice-distortion-and-interlayer-spacing-measurements-of-bilayer-and-trilayer-2d-materials(8684829d-4d4c-4031-ac51-fa95d2dd4240).html