Multiple scattering in the x-ray-absorption near-edge structure of tetrahedral Ge gases.

Abstract

X-ray-absorption fine-structure (XAFS) measurements of ${\mathrm{GeCl}}_{4}$, ${\mathrm{GeH}}_{3}$Cl, and ${\mathrm{GeH}}_{4}$ were made. We experimentally isolate the single- and multiple-scattering terms in the XAFS of ${\mathrm{GeCl}}_{4}$ by comparison of the spectra of the three compounds. The multiple-scattering (MS) amplitude is comparable to the single-scattering (SS) amplitude only within 15 eV of the edge. Beyond 40 eV the MS to SS amplitude ratio is less than 0.06. Calculations are in qualitative agreement with experiment. Our results suggest that XAFS data in the range 13A${\r{}}^{\mathrm{\ensuremath{-}}1}$ can be analyzed in a SS picture in many cases.