The post-peak spectra in electron energy loss near edge structure.

The origin of post-peak spectra in electron energy loss near edge structure (ELNES) spectra of pure Ni and NiO is investigated through ab initio calculation. Contrary to the general view that post-peak spectra in ELNES are generated by transitions to continuum states, it is found that orbit hybridization is the main cause of post-peak spectra in the low energy range above the Fermi level based on the calculation of electronic structure and ELNES. Reasons for the intensity differences of the simulated and experimental spectra are discussed. This work contributes to the understanding of ELNES and to the quantification of ELNES spectra.