Nucleation and growth of a quasicrystalline monolayer: Bi adsorption on the fivefold surface of i-Al70Pd21Mn9

Scanning tunneling microscopy has been used to study the formation of a Bi monolayer deposited on the fivefold surface of i-Al70Pd21Mn9. Upon deposition of low submonolayer coverages, the nucleation of pentagonal clusters of Bi adatoms of edge length 4.9 Å is observed. The clusters have a common orientation leading to a film with fivefold symmetry. By inspection of images where both the underlying surface and the Bi atoms are resolved, the pentagonal clusters are proposed to nucleate on pseudo-Mackay clusters truncated such that a Mn atom lies centrally in the surface plane. The density of these sites is sufficient to form a quasiperiodic framework, and subsequent adsorption of Bi atoms ultimately leads to the formation of a quasicrystalline monolayer. The suggested nucleation site is different from that proposed on the basis of recent density-functional theory calculations. Disciplines Condensed Matter Physics | Metallurgy Comments This article is from Physical Review B 78 (2008): 075407, doi:10.1103/PhysRevB.78.075407. Authors J. A. Smerdon, J. K. Parle, L. H. Wearing, Thomas A. Lograsso, A. R. Ross, and R. McGrath This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/ameslab_pubs/87 Nucleation and growth of a quasicrystalline monolayer: Bi adsorption on the fivefold surface of i-Al70Pd21Mn9 J. A. Smerdon, J. K. Parle, and L. H. Wearing Surface Science Research Centre and Department of Physics, The University of Liverpool, Liverpool L69 3BX, United Kingdom T. A. Lograsso and A. R. Ross Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA