Extended X-ray absorption fine structure (EXAFS) refers to a technique used in X-ray spectroscopy to analyze the local atomic structure of a material in solid, liquid, or gaseous states. EXAFS is an abbreviation for Extended X-ray Absorption Fine Structure, and it obtained its name from the fine oscillations observed in the X-ray absorption spectra.
EXAFS relies on the principle that when X-rays are directed towards a sample, they undergo absorption by core electrons. This absorption causes a decrease in the X-ray intensity, which is then measured to obtain the absorption spectrum. The resulting spectrum provides information about the absorbing atom's electronic state and the surrounding atomic environment.
In EXAFS analysis, the spectral oscillations beyond the absorption edge are closely examined. These oscillations represent the scattered X-ray waves resulting from the interaction of the outgoing photoelectron with neighboring atoms in the material. By mathematically analyzing these oscillations, scientists can deduce details about the surrounding atoms, including their distance, coordination number, and bond angles.
The EXAFS technique is widely used in various fields, including chemistry, materials science, biology, and environmental science. It offers valuable insights into the atomic structure of materials on a nanoscale level. By understanding the local atomic arrangement, researchers can elucidate important properties and behaviors of materials, such as their catalytic activity, electronic structure, and bonding characteristics.
In summary, EXAFS is a powerful technique that utilizes X-ray spectroscopy to probe the local atomic structure of materials. It allows scientists to gain a better understanding of the composition and arrangement of atoms, facilitating the development of new materials and advancements in various scientific disciplines.
