What is the difference between exafs and xanes?
EXAFS (Extended X-ray Absorption Fine Structure) yields information about the interatomic distances, near neighbor coordination numbers, and lattice dynamics. XANES (X-ray Absorption Near Edge Structure), on the other hand, gives information about the valence state, energy bandwidth and bond angles.
What does xanes measure?
Operando X-ray Absorption Near Edge Spectroscopy (XANES) is an analytical technique used to elucidate the local electronic structure of an atom as it evolves throughout a reaction or electrochemical process.
What is the meaning of XAS?
X-ray absorption spectroscopy
Definition. X-ray absorption spectroscopy (XAS) is a technique for measuring the linear absorption coefficient µ(E) of a substance as a function of the incident photon energy E in the X-ray regime. XAS conventionally includes techniques of XAFS, which in turn includes both XANES and EXAFS.
What information does Xanes?
X-ray absorption near-edge structure (XANES) spectra provide detailed information about the oxidation state and coordination environment of the metal atoms (Fig. 2). The K-edge absorption edge energy increases with increasing oxidation state.
What is Exafs analysis?
Analysis of the extended x-ray-absorption fine-structure (EXAFS) provides fine details of the partial pair distribution functions of atoms surrounding the absorber, including distances, mean square deviations in distance, coordination numbers, and coordinating species.
What is K edge absorption?
The K-absorption edge (K-edge) refers to the abrupt increase in the photoelectric absorption of x-ray photons observed at an energy level just beyond the binding energy of the k-shell electrons of the absorbing atom.
What information does XANES?
What is EXAFS analysis?
What are the applications of EXAFS?
Frequent use of EXAFS occurs in environmental chemistry, where scientists try to understand the propagation of pollutants through an ecosystem. EXAFS can be used along with accelerator mass spectrometry in forensic examinations, particularly in nuclear non-proliferation applications.
What is K in EXAFS?
Definition. Extended X-ray absorption fine structure (EXAFS) is the portion of XAFS spectra well above an absorption edge – typically starting ~ 50 eV above the absorption edge. where k is the photoelectron wavenumber, E is the X-ray energy, E_0 is the energy of the absorption edge, and m_e is the electron mass.