VIBRATIONS AT AG-AU INTERFACES

Using the pseudopotential approximation and pair core-core interaction potentials the interface vibrational modes for the Ag(001)-Au(001), A g(011)-Au(011) and Ag(111)-Au(111) interfaces have been calculated. Th e interface phonon modes localized on one side of the boundary between the constituent solids have been found for all the interfaces studied . The phonons localized on both sides of the boundary were observed at the Ag(011)-Au(011) and Ag(111)-Au(111) interfaces. In the case of th e (001) boundary there are interface modes lying outside the bulk vibr ational spectrum of Au and Ag. At other interfaces similar modes do no t exist. It is shown that a substitutional disordering at the interfac es changes the vibrational interface structure.