By means of soft-x-ray photoemission Citrin and Hamann have observed core level shifts of Ne, Ar, Kr, and Xe atoms implanted in the noble metals and have constructed a theoretical model with which to interpret the results. We describe calculations employing a quite different approach to the same physical effects which are as successful numerically. The two salient elements are the energy associated with the screening of the core hole by the host-metal electrons and the potential shift arising from the surface dipole of the metal, neither of which is present in the free-atom case. Also considered is the chemical shift due to implantation in the host; estimates of this depend upon details of the model describing the implant site, but for the case at hand we find this contribution to be small.
Citation: Physical Review B (Condensed Matter and Materials Physics)
Pub Type: Journals