The Au3Pd surface studied by ion scattering and LEED

S. Speller1, M. Aschoff1, J. Kuntze1, W. Heiland1, A. Atrei2, U. Bardi3, E. Platzgummer4

1Universität Osnabrück, D-49069 Osnabrück, Germany
2Dipartimento di Scienze e Tecnologie Chimiche e dei Boisistemi, Università di Siena, I-53100 Siena, Italy
3Dipartimento di Chimica, Università di Firenze, I-50121 Firenze, Italy
4Institut für Allgemeine Physik, Technische Universität Wien, A-1040 Wien, Austria

Surf. Rev. Lett. 6 (1999) 829

The (001) surface of a Au3Pd single crystal was studied with different surface analytical techniques. The main results reported about structure, composition and dynamics of the surface are based on ion scattering methods and LEED. We find segregation of Au to the surface forming a complete Au overlayer. The second layer has approximately the bulk Pd concentration. There is no evidence for chemical order in the near surface layers, i.e., Pd is randomly distributed in the lattice. The Au and Pd atoms in the first and the second layer respectively have approximately the same thermal vibrational amplitudes.