NEXAFS: Near Edge X-ray Absorption Fine Structures

Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy refers to the absorption fine structure close to an absorption edge, about the 10 eV below the absorption edge and 20 eV above the edge. This region usually shows the largest variations in the X-ray absorption coefficient and is often dominated by intense, narrow resonances. This technique provides information on the electronic structure of the unoccupied levels and very few techniques can do this. It can give orientatinal information. NEXAFS is also called X-ray Absorption Near Edge Structure, XANES. Today, the term NEXAFS is typically used for soft X-ray absorption spectra (surface science, organics) and XANES for hard X-ray spectra (coordination chemistry, metal atoms).