Effects of spin-orbit interaction in photoelectron scattering process for magnetic EXAFS.

We present an effect of the spin-orbit interaction (SOI) at surrounding atoms on K-edge magnetic extended x-ray absorption fine structure (MEXAFS). A contribution of the SOI to a K-edge MEXAFS spectrum is described by a perturbative way within a multiple scattering (MS) theory. A numerical calculation shows that a photoelectron single scattering by the SOI at surrounding atomic sites has a negligibly small contribution to MEXAFS. Although a negligible contribution of the SOI at surrounding atoms has been attributed to a cancellation of various MS contributions, this small contribution can be understood by the small number of its effective partial wave components, at least within the single scattering approximation. For further detailed analyses of MS with a path expansion method, only the small number of the partial wave components for the SOI is necessary. This leads to faster computations for MEXAFS including the photoelectron scattering by the SOI. • The single scattering term of the spin-orbit interaction at scattering sites has a negligible contribution to magnetic EXAFS. • This result substantially differs from the case of x-ray magnetic circular dichroism. • This small contribution comes from the narrow effective range of the spin-orbit interaction. [ABSTRACT FROM AUTHOR]