Münster 1997 – wissenschaftliches Programm
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O: Oberflächenphysik
O 7: Epitaxie/Wachstum auf Metallen
O 7.8: Vortrag
Montag, 17. März 1997, 17:45–18:00, S 10
Adlayer core-level shifts of random metal overlayers on transition metal substrates — •M. V. Ganduglia-Pirovano1, J. Kudrnovský2,3, and M. Scheffler1 — 1Fritz-Haber-Institut der MPG, D-14195 Berlin-Dahlem — 2Institute of Physics, ASCR, CZ-180 40 Praha 8 — 3CMS, Technical University, A-1060 Vienna
We calculate the difference of the
ionization energies of a core-electron of a surface alloy,
i.e., a B-atom at the AxB1−x overlayer on an fcc-B(001)-substrate,
and a
core-electron of the clean B(001) surface
using density-functional-theory together with the
tight-binding linear-muffin-tin orbital
surface Green function method.
We analyze the initial-state contributions and the screening
effects induced by the core hole, and we study
the influence of the alloy composition.
Data are presented for CuxPd1−x/Pd(100),
AgxPd1−x/Pd(100),
PdxCu1−x/Cu(100),
and
PdxAg1−x/Ag(100), changing
x from 0 to 100 %.
It is shown that screening effects can be very important rendering
the standard analysis of adlayer core-level shifts an (in general)
unreliable tool for analyzing trends in chemical reactivity. However, if
used in combination with state-of-the-art theory significant information
can be revealed.