Auger Electron Yields XAFS Measurement Using Synchrotron Radiation-Application to Element-Selective Analysis and Chemical State Analysis

N. Matsubayashi, H. Shimada, M. Imamura, Y. Yoshimura, T. Sato, and A. Nishijima
[Adv. X-ray Chem. Anal., Vol.25, pp.147-158, 1994]

Auger electron yield XAFS was applied to element-selective analysis and chemical state analysis for MoS₂ and Na₂ S₂ O₃ Mo L absorption edges appeared on a higher energy side of S K-edge in XAFS spectra for MoS₂ measured by total electron yield and conventional Auger electron yield. They were obstacles to EXAFS analysis for S K-edge of MoS₂ . Therefore three-dimensional S KLL Auger electron spectra were measured by scanning both kinetic energy of electron and incident X-ray energy from synchrotron radiation. The Mo L-edges were removed from S K-edges XAFS for MoS₂ by substraction of background in the three dimensional S KLL Auger electron spectra. EXAFS analysis for the S K-edge of MoS₂ was successfully done. S K-edge XAFS spectra of S^2- and S⁶⁺ in [S^2- -S⁶⁺ -O₃]^2- were obtained individually by curve-fitting for Auger electron peaks corresponding to S^2- and S⁶⁺ split by chemical shifts. Radial distribution functions around S^2- and S⁶⁺ were obtained individually from the spectra.