Co adatoms on Au(1 0 0): energetics of site exchange

The local approximation of the density functional theory and KKR Green's function method are used to investigate energetics of Co adatoms on the ideal Au(1 0 0) surface. Total energy calculations show that Co atoms and small Co clusters prefer to be embedded inside the substrate. The nearest-neighbor interaction between Co atoms in the gold substrate, being attractive, is small. Therefore, the instability of embedded Co clusters is expected.