Individual heteroatom identification with X-ray spectroscopy
Abstract
Individual heteroatoms in nanoscale materials often play a pivotal role in materials properties. To obtain maximum control over materials properties, researchers must be able to detect and identify diverse heteroatoms in samples with varying thickness and composition. Here, we demonstrate the identification of individual Si, S, P, and Ca heteroatoms in two-phase carbonaceous nanoscale mixtures with energy dispersive X-ray spectroscopy in a scanning transmission electron microscope. In order to fully demonstrate the robustness of the technique and the potential advantages over electron energy loss spectroscopy for single-atom speciation, no a priori constraint was placed on the sample thickness or types of heteroatom species. The various heteroatoms were identified with X-ray spectrum collection times ranging from 8 to 57 s, and normalized count rates of 0.096–0.007 counts s−1 pA−1. The lowest times/highest effective count rates were achieved by maximizing the effective dwell time on the atom, through minimizing the oversampling area of the electron beam raster.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 18, 2016
- Source ID
- 10.1063/1.4947002
Entities
People
- A. Kaeppel
- G. J. Corbin
- M. Falke
- M. Noack
- M. Rohde
- N. D. Bassim
- N. Dellby
- O. L. Krivanek
- P. Hrncirik
- Rhonda Stroud
- T. C. Lovejoy
- W. Hahn
Organizations
- Bruker Nano GmbH
- National Aeronautics and Space Administration
- Office of Naval Research
- United States Naval Research Laboratory