IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Thursday Sessions
       Session SS1-ThM

Paper SS1-ThM8
Nucleation and Growth of Al and Ag Thin Films on Five-fold Surface of Icosahedral Quasicrystals

Thursday, November 1, 2001, 10:40 am, Room 121

Session: Quasicrystals
Presenter: T. Cai, Iowa State University
Authors: T. Cai, Iowa State University
V. Fournee, Iowa State University
T.A. Lograsso, Iowa State University
A.R. Ross, Iowa State University
P.A. Thiel, Iowa State University
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Aluminium and silver are deposited on the five-fold surface of icosahedral Al-Cu-Fe and Al-Pd-Mn quasicrystals. The nucleation and growth of thin metal films on quasicrystalline surface are studied using scanning tunnelling microscopy. Our first results on Al films deposited on Al-Cu-Fe show that, at low coverage, Al atoms form pentagonal stars, all adopting the same orientation, though with no evidence of order between the Al pentagonal stars. As Al coverage is increased, but still within the submonolayer regime, the density of Al pentagonal stars increases. The five-fold symmetry of the quasicrystalline substrate is responsible for arranging deposited atoms with a local five-fold symmetry, which is incompatible with the translation periodicity of the cubic lattice of the individual elements. With scanning tunnelling microscope, we expect to observe directly the transition from a pentagonal symmetry to the face-centred cubic symmetry as the metallic film develops on the quasicrystalline surface.