Characterization & Correction of Self-Absorption Distortion in XANES


X-ray absorption spectroscopy (XAS) is an experimental technique used to probe the atomic properties of materials. XAS measurements performed in fluorescence mode are subject to so-called “self-absorption” distortion, especially when the sample under investigation is thick or concentrated with respect to the atom of interest. Here we investigate the behavior of self-absorption and present several suggestions to avoid and manage self-absorption through experimental design. Particularly, we find that it is easier to correct for very thick samples than for samples of intermediate thickness. Self-absorption distortion necessitates a correction of the measured spectrum during data processing. We present a technique for correcting self-absorbed spectra in the XANES region that is effective for all sample thicknesses and experimental geometries.