EXAFS and X-Ray Absorption Spectroscopy

Extended X-ray absorption fine structuret (EXAFS) refers to the modulation in the X-ray absorption coefficient beyond an absorption edge. Such modulations can extend up to about 1000 eV beyond the edge and have a magnitude of typically less than 20% of the edge jump. 

In the presence of one or more near neighbors, there will be modulations in the absorption coefficient as we scan out to energies about 1000 eV beyond the edge. The modulations present at energies from about 40 eV to 1000 eV beyond the edge are termed EXAFS. 

In addition to the EXAFS region, Fig. 6 shows that there are also three other regions the pre-edge, edge, and near-edge regions. 

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