J. Phys. I France
Volume 3, Numéro 7, July 1993
Page(s) 1649 - 1659
DOI: 10.1051/jp1:1993207
J. Phys. I France 3 (1993) 1649-1659

Inelastic mean free path and phase-shift determinations in NiO, using EXELFS

Mohammad A. Tafreshi1, Stefan Csillag1, Zou Wei Yuan1, Christian Bohm1, Elisabeth Lefèvre2 and Christian Colliex2

1  Institute of Physics, University of Stockholm, Vanadisvagen 9, S-113 46 Stockholm, Sweden
2  Laboratoire de Physique des Solides, Bât. 510, Université Paris Sud, 91405 Orsay, France

(Received 22 September 1992, accepted in final form 2 March 1993)

Structural and chemical information about the local atomic environment in a specimen can be obtained by analysing the EXELFS-modulations occurring beyond energy loss ionization edges. Using spectra recorded from a thin NiO sample, this paper reviews the problems and possibilities associated with distance and intensity analysis in EXELFS. Knowing a priori the structure of the sample, one can determine unknown parameters involved in the analysis of the data such as an average value of the inelastic mean free path for the ejected electrons, a linear approximation for the k-dependence of the oxygen $\Phi_{0-}$, oxygen-oxygen pair $\Phi_{0-0}$, and nickel backscattering $\Phi_{\rm {-Ni}}$, phase shifts.

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