By using computational methods, structural optimization calculations were performed with regard to generalized-gradient approximations to the Ag(111) (v3 x v3) R30º-Sb and Cu(111) (v3 x v3)R30º-Sb surface phases. Experimental studies had suggested that the outermost alloy layer of such surfaces contained substrate and Sb atoms in the hexagonal close-packed hollow sites; thus leading to stacking faults at the alloy/substrate interface. The results confirmed that these structures had a lower total energy than did unfaulted geometries. In the case of Ag(111), the stacking-fault energy for a clean surface layer was especially low. It became negative in the presence of partial Sb substitution. The relative energies of alternative Sb surface structures on Ag(111) were consistent with those of previous theoretical calculations, and the detailed geometries of the 2 optimum structures agreed well with experimental data.

Sb-Induced Surface Stacking Faults at Ag(111) and Cu(111) Surfaces - Density-Functional Theory Results. D.P.Woodruff, J.Robinson: Journal of Physics - Condensed Matter, 2000, 12[35], 7699-704