The analysis of x-ray absorption fine structure: beam-line independent interpretation

Abstract

Can current experimental techniques and analytical procedures produce x-ray absorption fine structure (XAFS) which is independent of the beam line or synchrotron used? We investigate the consequence upon XAFS interpretation of typical systematic errors, including determination of the edge energy, detector response and synchrotron bandwidth. Using the highest accuracy data set of the mass-attenuation coefficient collected so far, we consider a series of systematic effects in the analyses of both the near-edge and extended energy regions of the spectrum. We investigate whether conclusions derived from an experiment using a given analytical procedure are consistent when performed on different synchrotron beam lines. We find that the effectiveness of common XAFS analysis is limited by experimental and data reduction techniques, particularly relating to determinations of photon energy. By correcting for all major systematic errors in XAFS data, one can determine bond lengths more robustly and with greater accuracy.

Long range interactions in nanoscale science

“…The high intensities and wide range of wavelengths available from synchrotron sources permit determination of local ordering, even in glasses and other amorphous or weakly crystalline materials ͑Egami, 2004, 2007͒. X-ray absorption and fluorescence provide direct identification of the specific elements interacting with the beam, and methods such as absorption fine structure, near-edge, and photoelectron spectroscopy can be used to determine the valence state of the target element and its nearestneighbor distributions and elemental compositions ͑Evans et Glover and Chantler, 2007;Wada et al, 2007͒. 3D …”

X-ray mass attenuation coefficients and imaginary components of the atomic form factor of zinc over the energy range of 7.2–15.2 keV

“…It is essential that the dark current be measured and corrected for in any x-ray absorption experiment, including XAFS and XANES experiments [29,60].…”

New consistency tests for high-accuracy measurements of X-ray mass attenuation coefficients by the X-ray extended-range technique

“…X-ray absorption spectroscopy (XAS) experiments are now mostly dependent on synchrotron sources, providing unparalleled scope for new experimental techniques in material analysis and accurate measurement of XAFS (Lytle, 2007;Chantler, 2010). A complete quantitative treatment of XAS is still challenging owing to a range of experimental and analytical complications (Rehr & Ankudinov, 2001;Smale et al, 2006;Glover & Chantler, 2007;. Experimental methods can address potential impediments and optimistically lead to a quantitative treatment of XAS.…”