Decision process for comparison of partial and complete XANES spectra

Abstract

If the range of XANES spectra varies between sets of scans, it may be impossible to compare sets of spectra unless a restricted part of the spectra is used. The paper derives a decision process for comparison of partial and complete XANES spectra, taking lead as an example. Lead L3-edge XANES spectra were collected at the Australian National Beamline Facility (BL-20B) Photon Factory, Tsukuba, Japan over the energy range 13,000-13,150 eV (ring conditions: 2.5 GeV, 300-400 mA). The monochromator step size was reduced to 0.25 eV per step in the XANES region (13,000-13,100 eV and 13,040-13,100 eV) to collect high-resolution spectra. XANES data for samples and model compounds were collected at ambient temperature and pressure in fluorescence, using simultaneous collection of a Pb metal reference foil for energy calibration (first derivative peak of elemental Pb was 13,050 eV). XANES spectra were fitted using spectral deconvolution and least-squares linear combination fitting (LCF). Detailed XANES results with LCF approach over various energy ranges are illustrated and discussed and show the applicability of the decision-making procedure to compare sets of spectra. © 2010 American Institute of Physics.