Figure 7
The charge of an Fe atom versus Cr configurations (with the neutral atom, of charge 0 e, as the reference level). The axis labels ‘Pure Fe’, ‘Cr in 1L’, ‘Cr in 2L’ and ‘2Cr in 2L’ refer to pure Fe surface, one Cr atom in the surface layer, one Cr atom in the subsurface layer and two Cr atoms in the subsurface layer at sites 8 and 9 (Fig. 1). The green curve with square markers shows the charge of the subsurface Fe atom nearest to the Cr atom. The blue curve with filled circles gives the charge of the surface Fe atom nearest to the Cr atom. For the ‘2Cr in 2L’ case, the red branch (open circle) shows the charge of the Fe atom at site 5, and the blue branch (filled circle) shows the charge of an Fe atom at sites 2 and 4.
