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Your search keyword '"Wearing, L. H."' showing total 14 results
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14 results on '"Wearing, L. H."'

1. Nucleation and growth of a quasicrystalline monolayer: Bi adsorption on the five-fold surface of i-Al70Pd21Mn9

Author

Smerdon, J. A., Parle, J. K., Wearing, L. H., Lograsso, T. A., Ross, A. R., and McGrath, R.

Subjects
Condensed Matter - Other Condensed Matter
Abstract

Scanning tunnelling microscopy has been used to study the formation of a Bi monolayer deposited on the five-fold surface of i-Al70Pd21Mn9. Upon deposition of low sub-monolayer coverages, the nucleation of pentagonal clusters of Bi adatoms of edge length 4.9 A is observed. The clusters have a common orientation leading to a film with five-fold symmetry. By inspection of images where both the underlying surface and the Bi atoms are resolved, the pentagonal clusters are found 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 initial nucleation site is different to that proposed on the basis of recent density functional theory calculations., Comment: 6 pages, 5 figures

Published
2008
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2. Self-assembly, structure and electronic properties of a quasiperiodic lead monolayer

Author

Ledieu, J., Leung, L., Wearing, L. H., McGrath, R., Lograsso, T. A., Wu, D., and Fournée, V.

Subjects
Condensed Matter - Materials Science
Abstract

A quasiperiodic Pb monolayer has been formed on the five-fold surface of the Al-Pd-Mn quasicrystal. Growth of the monolayer proceeds via self-assembly of an interconnected network of pentagonal Pb stars, which are shown to be tau-inflated compared to similar structural elements of the quasiperiodic substrate. Measurements of the electronic structure of the system using scanning tunnelling spectroscopy and ultra-violet photoemission spectroscopy reveal that the Pb monolayer displays a pseudo-gap at the Fermi level which is directly related to its quasiperiodic structure., Comment: 4 pages, 4 figures

Published
2007
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4. Quantitative Adsorbate Structure Determination for Quasicrystals Using X-Ray Standing Waves

Author

Diehl, R. D., primary, Li, H. I., additional, Su, S. Y., additional, Mayer, A., additional, Stanisha, N. A., additional, Ledieu, J., additional, Lovelock, K. R. J., additional, Jones, Robert G., additional, Deyko, A., additional, Wearing, L. H., additional, McGrath, R., additional, Chaudhuri, A., additional, and Woodruff, D. P., additional

Published
2014
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11. Ordering of adsorbed species on quasicrystal surfaces.

Author

Smerdon, J. A., Wearing, L. H., Parle, J. K., Leung, L., Sharma, H. R., Ledieu, J., and Mcgrath, R.

Subjects
*QUASICRYSTALS, *CRYSTALS, *CRYSTALLOGRAPHY, *ADSORPTION (Chemistry), *PHYSICAL & theoretical chemistry
Abstract

We present an overview of experimental studies of the structure of adsorbed atomic and molecular species on quasicrystal surfaces with a particular focus on those systems where quasiperiodic ordering of the adsorbate structure occurs. Atomic adsorption is illustrated with examples from studies of Fe and Gd adsorption on the five-fold surface of i-Al-Pd-Mn. Overlayer structure is correlated with several physical parameters to identify trends. It is concluded that the chemical properties of the adsorbate (metallic radius, electronegativity, melting temperature) are important indicators of quasiperiodic structuring of the adsorbate system. These correlations allow predictions of those elements likely to yield pseudomorphic overlayers. Structural effects upon molecular adsorption on clean quasicrystal surfaces have been less successful. A new approach to ordered molecular adsorption is described and illustrated for C60 adsorption on a Pb monolayer film on the ten-fold surface of d-Al-Ni-Co. [ABSTRACT FROM AUTHOR]

Published
2008
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12. Adsorption of cobalt on the tenfold surface of d -Al 72 Ni 11 Co 17 and on the fivefold surface of i -Al 70 Pd 21 Mn 9.

Author

Smerdon, J. A., Ledieu, J., Hoeft, J. T., Reid, D. E., Wearing, L. H., Diehl, R. D., Lograsso, T. A., Ross, A. R., and McGrath, R.

Subjects
COBALT, ADSORPTION (Chemistry), SCANNING tunneling microscopy, SCANNING Auger electron microscopy, LOW energy electron diffraction, PARTICLES (Nuclear physics)
Abstract

The adsorption behaviour of Co on the tenfold surface of d -Al 72 Ni 11 Co 17 and on the fivefold surface of i -Al 70 Pd 21 Mn 9 has been studied using scanning tunnelling microscopy (STM), Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED). The analysis of a distinctive quasiperiodic LEED pattern for coverages from 3–30?ML of Co on d -Al 72 Ni 11 Co 17 suggests that the Co forms in a pseudomorphic row structure composed of domains of Fibonacci spaced rows having a periodic lattice parameter along the rows of 2.5?±?0.1?Å. The same structure, though less well-ordered and with a larger lattice parameter, is formed on the fivefold surface of i -Al 70 Pd 21 Mn 9 . [ABSTRACT FROM AUTHOR]

Published
2006
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