Multi-Mode Elastic Peak Electron Microscopy (MM-EPEM): A new imaging technique with an ultimate in-depth resolution for surface analysis

Mohamed Aymen Mahjoub; Guillaume Monier; Luc Bideux; Bernard Gruzza; Christine Robert-Goumet

doi:10.1016/j.ultramic.2018.02.008

Multi-Mode Elastic Peak Electron Microscopy (MM-EPEM): A new imaging technique with an ultimate in-depth resolution for surface analysis

Ultramicroscopy. 2018 May:188:13-18. doi: 10.1016/j.ultramic.2018.02.008. Epub 2018 Feb 28.

Authors

Mohamed Aymen Mahjoub¹, Guillaume Monier², Luc Bideux¹, Bernard Gruzza¹, Christine Robert-Goumet¹

Affiliations

¹ Institut Pascal, Université Clermont Auvergne, CNRS, SIGMA, F-63000 Clermont-Ferrand, France.
² Institut Pascal, Université Clermont Auvergne, CNRS, SIGMA, F-63000 Clermont-Ferrand, France. Electronic address: guillaume.monier@uca.fr.

PMID: 29518620
DOI: 10.1016/j.ultramic.2018.02.008

Abstract

A non-destructive new imaging technique called Multi-Mode Elastic Peak Electron Microscopy (MM-EPEM), hypersensitive to surface chemistry and with an in-depth resolution of one atomic monolayer was developed. This method consists on performing several MM-EPEM images containing n × n pixels associated to an intensity of the elastic backscattered electrons by varying the incident electron energy in the range 200-2000 eV. This approach allows obtaining depth sampling information of the analyzed structures. Furthermore, MM-EPEM is associated with Monte-Carlo simulations describing the electron pathway in materials in order to obtain very precise quantitative information, for instance the growth mode and the organization of ultra-thin layers (2D materials) or nanoparticules. In this work, we used this new method to study the deposition of very small amount of gold down to one monolayer. Example of 3D reconstruction is also provided.

Keywords: 2D materials; Elastic backscattered electrons; Elastic peak electron spectroscopy; Electron microscopy; Monte Carlo simulation; Nanoparticules.