X-ray absorption near-edge spectroscopy

synonym: near-edge extended X-ray absorption fine structure spectroscopy (NEXAFS)
acronym: XANES
https://doi.org/10.1351/goldbook.09213
X-ray absorption fine structure spectroscopy in the energy region near (within approximately \(\pu{100 eV}\)) an absorption edge.
Notes:
  1. XANES results from interference in multiple scattering of low-energy photoelectrons by surrounding atoms. It provides information on the local coordination environment, oxidation state, molecular orbitals, hybridization, and band structure (unoccupied electronic states).
  2. XANES measurements usually start some \(\pu{10 eV}\) before the core-level binding energy (the absorption edge) of the emitting atoms, because in many cases pre-edge features are used to identify chemical bonds, e.g. \(\uppi\!^*\) resonances (excitation into lowest unoccupied molecular orbitals) in C K-edge spectra of polymer samples.
  3. Usefully sharp absorption edges are commonly observed in X-ray absorption spectra, although broader increases can be observed for some inner-shell excitations with short lifetimes.
Source:
PAC, 2020, 92, 1781. (Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)) on page 1795 [Terms] [Paper]