Electron Microscopy and Scanning Microanalysis
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Oleshko, V., Gijbels, R. and Amelinckx, S. 2006. Electron Microscopy and Scanning Microanalysis. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
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In analytical electron microscopy (AEM), several imaging, diffraction and analytical modes are integrated in a design to provide analytical synergism having obvious advantages over any single instrument. The subject of AEM is to determine the morphology, crystallinity, defect structure, phase and elemental compositions and electronic properties of a material using the focused electron beam and signals generated in the course of its interaction with the specimen. The article considers history and stages of development of AEM, theoretical aspects of electron beam–solid interactions, instrumentation and methodology of particular techniques and image analysis, sample preparation and some typical applications. Various electron–specimen interactions generate a great deal of structural and analytical information in the form of emitted electrons and/or photons and internally produced signals, such as elastically and inelastically scattered electrons, Auger electrons (AE), X-rays and cathodoluminescence (CL), which can be analyzed in different operating modes. Imaging of transmitted solid materials is essentially due to elastic scattering (diffraction) of electrons by the periodic arrangement of atoms in crystals (diffraction contrast) and/or interference of several diffracted and transmitted beams (phase contrast). High-resolution imaging in the scanning transmission mode is also possible by using incoherently scattered electrons (Z-contrast). Inelastic interactions are forming the basis for all chemical analytical techniques (energy-dispersive (X-ray) spectroscopy (EDS) and wavelength-dispersive (X-ray) spectroscopy (WDS), electron energy-loss spectroscopy (EELS)/energy-filtering transmission electron microscopy (EFTEM), AE and CL spectroscopy). Basic data characterizing state-of-the-art modern AEM and current trends in its development are presented.