Multi-atom resonant photoemission

Abstract

We review the present status of multi-atom resonant photoemission (MARPE), in which the photoelectron intensity from a core level on one atom is influenced by core-level absorption resonances on neighboring atoms of different atomic number. We find that some prior experimental data has been strongly influenced by detector non-linearity and that the effects seen in new corrected data are generally smaller and of different form. The corrected data are found to be well described by an extension of resonant photoemission theory to the interatomic case, provided that interactions beyond the usual second-order Kramers–Heisenberg treatment are included. This microscopic X-ray theory is also found to simplify under certain conditions so as to yield results equivalent to a classical X-ray optical approach, with the latter providing an alternative, although less detailed and general, physical picture of these effects. The present status of experimental results for such MARPE effects is discussed, together with the potential utility of these effects as near-neighbor probes, as well as their implications for X-ray emission and X-ray scattering experiments.