Title

Diffraction paradox: An unusually broad diffraction background marks high quality graphene

Publication Date

10-15-2019

Department

Ames Laboratory; Chemistry; Materials Science and Engineering; Physics and Astronomy

Campus Units

Ames Laboratory, Chemistry, Materials Science and Engineering, Physics and Astronomy

OSTI ID+

1574018

Report Number

IS-J 10074

DOI

10.1103/PhysRevB.100.155307

Journal Title

Physical Review B

Volume Number

100

Issue Number

15

First Page

155307

Abstract

The realization of the unusual properties of two-dimensional (2D) materials requires the formation of large domains of single-layer thickness, extending over the mesoscale. It is found that the formation of uniform graphene on SiC, contrary to textbook diffraction, is signaled by a strong bell-shaped component (BSC) around the (00) and G(10) spots (but not around the substrate spots). The BCS is also seen on graphene grown on metals, because a single uniform graphene layer can be also grown with large lateral size. It is only seen by electron diffraction but not with x-ray or He scattering. Although the origin of such an intriguing result is unclear, its presence in the earlier literature (but never mentioned) points to its robustness and significance. A likely mechanism relates to the the spatial confinement of the graphene electrons, within a single layer. This leads to large spread in their wave vector which is transferred by electron-electron interactions to the elastically scattered electrons to generate the BSC.

DOE Contract Number(s)

AC02-07CH11358; SFB1242

Language

en

Department of Energy Subject Categories

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Share

COinS