A detailed  ab initio  study was made of alloying processes, in the dilute limit, for 3d-type atoms on a (001) Fe surface. The calculations were based upon local density functional theory, and involved the use of a KKR-Green's function method for impurities on surfaces. It was found that, for essentially all 3d transition metal impurities on Fe (001), there was a marked tendency to direct exchange with the first surface layer. Early-3d impurities (V, Cr, Mn) strongly repelled each other at neighboring positions within the first layer, while Ni and Cu atoms exhibited moderate repulsion. The predictions were in good agreement with scanning tunnelling microscopic studies of Cr/Fe(001).

Energetics of 3d Impurities on the (001) Surface of Iron B.Nonas, K.Wildberger, R.Zeller, P.H.Dederichs: Physical Review Letters, 1998, 80[20], 4574-7