Open AccessTheory of photon interference X‐ray absorption fine structure
Author(s) -
Nishino Yoshinori,
Materlik Gerhard
Publication year - 2001
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049500016149
Subject(s) - extended x ray absorption fine structure , absorption (acoustics) , mean free path , x ray , atom (system on chip) , photon energy , scattering , intensity (physics) , interference (communication) , photon , range (aeronautics) , atomic physics , fourier transform , absorption cross section , two photon absorption , crystal (programming language) , molecular physics , optics , materials science , absorption spectroscopy , chemistry , physics , cross section (physics) , laser , channel (broadcasting) , programming language , electrical engineering , quantum mechanics , computer science , composite material , embedded system , engineering
The theory of photon interference X‐ray absorption fine structure (πXAFS) is described. Due to coherent X‐ray scattering from atoms, a spatial variation of the X‐ray intensity is produced inside the sample. The intensity at the X‐ray absorbing atom changes according to the incident energy. Thus πXAFS in extended absorption spectra is produced. It extends in a wide energy range over absorption edges. For powders the πXAFS formula has equivalent form as the EXAFS formula, and the Fourier transform provides distances of neighboring atoms from the absorbing atom. Due to a long mean free path of the photon, πXAFS for powders contains sharp structures. They are explained as a crystal grain orientation averaging of the X‐ray standing wave effect.