Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-13T04:35:34.039Z Has data issue: false hasContentIssue false
  • English
  • Français

Quantitative Composition and Thickness Mapping With High Spatial Resolution By XEDS In a 300kv FEG-AEM

Published online by Cambridge University Press:  02 July 2020

M. Watanabe  and
D. B. Williams
M. Watanabe
Affiliation:
Department of Materials Science and Engineering, Lehigh University, Bethlehem, PA, 18015, USA.
D. B. Williams
Affiliation:
Department of Materials Science and Engineering, Lehigh University, Bethlehem, PA, 18015, USA.
Get access

Extract

Since the first demonstration by Cosslett and Duncumb, X-ray mapping by an electron probe microanalyzer (EPMA) has become a most popular approach in microanalysis because elemental distributions of constituents in a bulk sample can be displayed visually. The major disadvantage of EPMA mapping is poor spatial resolution (∼ 1 μm). The spatial resolution of X-ray microanalysis can be improved to a few nanometers using electron transparent thin-specimens in the analytical electron microscope (AEM). However, X-ray count rates from thin specimens are strictly limited because of the improved spatial resolution (i.e. smaller interaction volume) and the poor collection efficiency of X-ray. To obtain reasonable counts for accurate quantification in the AEM, extraordinarily long mapping times are required. Therefore, quantitative X-ray mapping is rarely attempted in the AEM. However, these limitations can be overcome by use of intermediate-volt age instruments combined with field-emission guns to increase the beam current-density, careful stage design to maximize the X-ray collection efficiency and the peak-to-background ratio, and ultrahigh vacuum system to reduce contamination.

Type
Compositional Mapping With High Spatial Resolution
Information
Microscopy and Microanalysis , Volume 4 , Issue S2: Proceedings: Microscopy & Microanalysis '98, Microscopy Society of America 56th Annual Meeting, Microbeam Analysis Society 32nd Annual Meeting, Atlanta, Georgia July 12-16, 1998 , July 1998 , pp. 136 - 137
Copyright
Copyright © Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Cosslett, V. E. and Duncumb, P., Nature, 177(1956)1172.CrossRefGoogle Scholar
2.Lyman, C. E. et al., J. Microscopy, 176(1994)85.CrossRefGoogle Scholar
3.Watanabe, M. et al., Ultramicroscopy, 65(1996)187.CrossRefGoogle Scholar
4. The authors acknowledge the support of Bettis Labs and Westinghouse. Special thanks to Prof. Z. Horita of Kyushu University for providing the Ni-Al-Mo specimens and Mr. D. W. Ackland of Lehigh University for helpful discussions and technical assistance.Google Scholar