X-ray absorption spectroscopy: EXAFS (Extended X-ray Absorption Fine Structure) and XANES (X-ray Absorption Near Edge Structure)
The x-ray absorption spectroscopy (XAS) had been an essential tool to gather spectroscopic information about atomic energy level structure in the early decades of this century. It has also played an important role in the discovery and systematization of rare-earth elements. The discovery of synchrotron radiation in 1952, and later the availability of broadly tunable synchrotron based x-ray sources have revitalized this technique since the 1970's. The correct interpretation of the oscillatory structure in the x-ray absorption cross-section above the absorption edge by Sayers et. al. has transformed XAS from a spectroscopic tool to a structural technique. EXAFS (Extended X-ray Absorption Fine Structure) yields information about the interatomic distances, near neighbor coordination numbers, and lattice dynamics. An excellent description of the principles and data analysis techniques of EXAFS is given by Teo. XANES (X-ray Absorption Near Edge Structure), on the other hand, gives information about the valence state, energy bandwidth and bond angles. Today, there are about 50 experimental stations in various synchrotrons around the world dedicated to collecting x-ray absorption data from the bulk and surfaces of solids and liquids. In this chapter, we will give the basic principles of XAS, explain the information content of essentially two different aspects of the absorption process leading to EXAFS and XANES, and discuss the source and samples limitations.
- Research Organization:
- Argonne National Lab., IL (USA)
- Sponsoring Organization:
- DOE/ER; NSF
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 6851071
- Report Number(s):
- CONF-900190-1; ON: DE90011177; CNN: STC-8809854
- Country of Publication:
- United States
- Language:
- English
Similar Records
Laboratory x-ray spectrometer for EXAFS and XANES measurements
Combined in Situ X-ray absorption and diffuse reflectance infraredspectroscopy: An attractive tool for catalytic investigations
Related Subjects
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION SPECTRA
COPPER COMPOUNDS
CROSS SECTIONS
DISTANCE
ELECTRONIC STRUCTURE
FINE STRUCTURE
FLUORESCENCE
INTERATOMIC DISTANCES
LUMINESCENCE
PRASEODYMIUM COMPOUNDS
RARE EARTH COMPOUNDS
SPECTRA
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
X-RAY SPECTROSCOPY