Imaging the Spatial Distribution of Electronic States in Graphene Using Electron Energy-Loss Spectroscopy: Prospect of Orbital Mapping.

M Bugnet,V K Lazarov,M Ederer,Q M Ramasse,D M Kepaptsoglou,S Löffler,L Li

doi:10.1103/physrevlett.128.116401

Abstract

The spatial distributions of antibonding π^{*} and σ^{*} states in epitaxial graphene multilayers are mapped using electron energy-loss spectroscopy in a scanning transmission electron microscope. Inelastic channeling simulations validate the interpretation of the spatially resolved signals in terms of electronic orbitals, and demonstrate the crucial effect of the material thickness on the experimental capability to resolve the distribution of unoccupied states. This work illustrates the current potential of core-level electron energy-loss spectroscopy towards the direct visualization of electronic orbitals in a wide range of materials, of huge interest to better understand chemical bonding among many other properties at interfaces and defects in solids.

Highlights

The spatial distributions of antibonding πÃ and σÃ states in epitaxial graphene multilayers are mapped using electron energy-loss spectroscopy in a scanning transmission electron microscope
This work illustrates the current potential of core-level electron energy-loss spectroscopy towards the direct visualization of electronic orbitals in a wide range of materials, of huge interest to better understand chemical bonding among many other properties at interfaces and defects in solids
Defects, interfaces, and surfaces have a direct influence on macroscopic material properties. Imaging electronic states, such as chemical bonds at crystal imperfections and discontinuities in real space, is of fundamental and technological interest to enable the development of new materials with novel functionalities

Summary

Introduction

Imaging the Spatial Distribution of Electronic States in Graphene Using Electron Energy-Loss Spectroscopy: Prospect of Orbital Mapping The spatial distributions of antibonding πÃ and σÃ states in epitaxial graphene multilayers are mapped using electron energy-loss spectroscopy in a scanning transmission electron microscope.

Results

Conclusion