Energetics of surface alloying: 3d adatoms on the Au(100) surface

Ab initio studies of energetics of surface alloying on an atomic scale are presented. We demonstrate that site ri;changes between 3d transition metal impurities on the Au(100) surface and Au atoms are energetically favorable. These results show that models of epitaxial growth based on an abrupt boun dary between components can be inadequate for all 3d transition metal nanos tructures on the gold surface. Consideration based on the energetics of imp urities in the gold surface leads to the conclusion that a random distribut ion of isolated impurities is expected in all systems investigated.