Identifiying a Single Atom on Graphene

Not only is it the highest art of EDS to obtain spectra of a single atom, but it can also provide valuable new information on the excitation properties of specific elements.

In this case a graphene monolayer containing a single silicon atom was analyzed using EELS and EDS simultaneously. With both methods the atom could be identified as Si. Also a Pt atom could be identified (data published in [1]; further reading in [2]). The EDS spectrum is shown in the lower image. Considering the beam current and acquisition time used, one would have expected roughly twice as many counts according to current models. As the finding was consistent for other elements as well, further investigation would be interesting.

Learn more: 

[1] Single atom identification by energy dispersive x-ray spectroscopy

Applied Physical Letter Volume 100, Issue 15 4101 (2012); Authors: T. C. Lovejoy, Q. M. Ramasse, M. Falke, A. Kaeppel, R. Terborg, R. Zan, N. Dellby, and O. L. Krivanek

[2] Individual heteroatom identification with X-ray spectroscopy (open access)

Applied Physical Letter Volume 108, Issue 16 3101 (2016); Authors:  R. M. Stroud, T. C. Lovejoy, M. Falke, N. D. Bassim, G. J. Corbin, N. Dellby, P. Hrncirik, A. Kaeppel, M. Noack, W. Hahn, M. Rohde, and O. L. Krivanek