Multiple-scattering approaches to carbon K-shell near-edge X-ray absorption fine structure of graphite

Abstract

The multiple-scattering cluster method was first employed to calculate the theoretical near-edge X-ray absorption fine structure (NEXAFS) spectrum of graphite. Studies on the polarization dependence on the incident vector E classify spectral features into pi and sigma resonances. Characterization of the carbon K-shell NEXAFS spectra of the species modelled by both a single layer and a multilayer has been performed. It reveals that a pi * resonance originally located at around 989 eV splits with the accumulation of the number of atoms included in the cluster. Multilayer calculation has little influence on the NEXAFS spectrum. Our calculation coincides with the experimental results fairly well. In addition, it has been found to be in good agreement with the final density of states derived from band-structure calculations.