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The Precession Technique in Electron Diffraction and Its Application to Structure Determination of Nano-Size Precipitates in Alloys

Published online by Cambridge University Press:  22 January 2004

J. Gjønnes ,
V. Hansen  and
A. Kverneland
J. Gjønnes
Affiliation:
Center for Materials Science, University of Oslo, Gaustadalleen 21, N-0349 Oslo, Norway
V. Hansen
Affiliation:
Stavanger University College, Department of Technology and Natural Sciences, P.O. Box 2557, Ullandhaug, N-4091 Stavanger, Norway
A. Kverneland
Affiliation:
Stavanger University College, Department of Technology and Natural Sciences, P.O. Box 2557, Ullandhaug, N-4091 Stavanger, Norway
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Abstract

Crystal structure of nano-scale precipitates in age-hardening aluminum alloys is a challenge to crystallography. The utility of selected area electron diffraction intensities from embedded precipitates is limited by double scattering via matrix reflections. This effect can be signally reduced by the precession technique, which we have used to collect extensive intensity data from the semicoherent, metastable η′-precipitate in the Al-Zn-Mg alloy system. A structure model in the space group P-62c is proposed from high-resolution microscopy and electron diffraction intensities. The advantages of using the precession technique for quantitative electron diffraction is discussed.

Keywords

electron diffractionprecession techniquealuminum alloyscrystal structure
Type
Research Article
Information
Microscopy and Microanalysis , Volume 10 , Issue 1 , February 2004 , pp. 16 - 20
Copyright
© 2004 Microscopy Society of America

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References

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