Spectral transformation of EXELFS data — NiO on Ni(100) and Ni(110)

Abstract

Extended electron energy loss fine structure (EXELFS) spectra have been obtained from the K-level of oxygen in NiO films grown on both the Ni(100) and Ni(110) surfaces. The spectra indicate that the oxide films grown on both surfaces have Ni-O bond lengths of 2.08 Å, identical to those of bulk NiO. These analyses agree with previous measurements on the Ni(100) surface. As in previous experiments the actual measurements made is of N( E) rather than direct measurement of the electron energy loss distribution N( E). The EXELFS spectra from these two surfaces are used to illustrate the influence of this collection scheme on the radial distribution function obtained by Fourier transformation of the raw data. To obtain the direct analog of the radial distribution function found from the EXAFS experiment one must either resort to spectral integration or appropriate scaling of the distribution function found from the EXELFS experiment.