Extended energy-loss fine structure EXELFS

Figure 7.26. Electron energy-loss spectroscopy (EELS) spectra. Shown (top) is a representative EELS spectrum of a nickel oxide sample. A typical EELS spectrum shows a zero-loss peak that represents the unscattered or elastically scattered electrons, the near-edge fine structure (ELNES), and extended energy-loss fine structure (EXELFS). Also shown (bottom) are the fingerprint regions of an EELS spectrum, just beyond the core-electron edges, which provide information regarding the detailed bonding and chemical environment of the desired element.

The occurrence of fine structures has already been noted in the sections on spectral information and ionization losses (Sects. 2.5.3 and 2.5.3.2). In the following text some principal considerations are made about the physical background and possible applications of both types of feature, i. e. near-edge and extended energy-loss fine structures (ELNES/EXELFS). A wealth of more detailed information on their usage is available, especially in textbooks [2.171, 2.173] and monographs [2.210-2.212]. 

EXELFS (the extended energy-loss fine structure) carries information about the bonding and co-ordination of the atoms contributing to the edge. However, the signal needs to be strong before statistically reliable information can be obtained. 

Extended X-Ray Energy Loss Fine Structure (EXELFS)... 

EXELFS extended energy loss fine structure... 

Extended electron energy loss fine structure (EXELFS) - See Techniques for Materials Characterization, page 12-1. 

EXELFS Extended X-ray Energy Loss Fine Structure A fine-structure technique similar to EXAFS, except that 60-300 KeV electrons rather than photons excite core-holes. Like EXAFS, this techniques is not explicitly surface sensitive. 

EXELFS Extended Electron Energy Loss Fine Structure Thin films Electrons (100-400 keV) Electrons energies 0-30 eV above edge <200 nm 1-100 nm Density of stales of valence eleclrons (above Fermi level) 27,32... 

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