Surface heat of segregation from surface core-level binding-energy shifts

The surface core-level shift for the $Z$ ($Z$ being the atomic number) component in a $Z_x{\mathrm{}(Z+1\mathrm{})\mathrm{}}_{1-x}$ metallic alloy is shown to be directly related to the surface heat of segregation of the ($Z+1\mathrm{}$) component. Measurements of surface core-level shifts can therefore be an accurate means to obtain this important thermodynamic quantity, which also enters as a crucial parameter in the quasichemical theory for surface segregation. The possibility to use the surface core-level binding energies for a determination of the energetics of the surface is also pointed out.