Fine Structure and Finer Details
In the previous chapter, we described elemental analysis using ionization edges, but there is much more than just elemental information in the ionization edges and this distinguishes EELS from XEDS. There are detailed intensity variations in the core-loss spectra called energy-loss near-edge structure (ELNES) and extended energy-loss fine structure (EXELFS). From this fine structure, which we can resolve because of the high-energy resolution inherent in EELS, we can obtain data on how the ionized atom is bonded, the coordination of that specific atom, and its density of states. As always, we can use any intensity changes to create filtered images which show the distribution of, e.g., regions of different bonding states. Furthermore, we can probe the distribution of other atoms around the ionized atom (i.e., determine the radial-distribution function (RDF) which is very useful for the study of amorphous materials) and we can study momentum-resolved EELS, observe the anisotropy of chemical bonds, combine EELS with tomography, inter alia.
KeywordsBulk Metallic Glass Core Hole Augmented Plane Wave Ionization Edge Multiple Scattering Method
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Books And Reviews
- Brydson, RMD, Sauer, H and Engel, W 2004 Probing Materials Chemistry using ELNES in Transmission Electron Energy Loss Spectrometry in Materials Science and the EELS Atlas 2nd Ed. 223–270 Ed. CC Ahn Wiley-VCH Weinheim Germany. Comprehensive review of chemical information via the ELNES spectrum; exceptional bibliography.Google Scholar
- Egerton, RF 1996 Electron Energy-Loss Spectroscopy in the Electron Microscope 2nd edition Plenum Press New York. Everything you need to know on fine structure.Google Scholar
- Koningsberger, DC and Prins, R 1988 X-Ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS and XANES Wiley New York. Probably more than you’ll ever want to know about the X-ray analogs of EELS.Google Scholar
- Raether, H 1965 Electron Energy-Loss Spectroscopy in Springer Tracts in Modern Physics Springer-Verlag New York. The source if you really want to know the physics of EELS.Google Scholar
Calculations And Technique
Momentum Transfer Studies
- Leapman, RD, Grunes, LA and Fejes, PL 1982 Study of the L 23 Edges in the 3d Transition Metals and Their Oxides by Electron-Energy Loss Spectroscopy with Comparisons to Theory. Phys. Rev. 25(12) 7157–73.Google Scholar
- Bruley, J, Williams, DB, Cuomo, JJ and Pappas, DP 1995 Quantitative Near-Edge Structure Analysis of Diamond-like Carbon in the Electron Microscope Using a Two-Window Method J. Microsc. 180 22–32.Google Scholar