Migration and abstraction of H-atoms from the Cu(1 1 1) surface

Luo, M.F., MacLaren, D.A. and Allison, W. (2005) Migration and abstraction of H-atoms from the Cu(1 1 1) surface. Surface Science, 586(1-3), pp. 109-114. (doi: 10.1016/j.susc.2005.05.003)

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Publisher's URL: http://dx.doi.org/10.1016/j.susc.2005.05.003

Abstract

Isothermal measurements of the helium specular reflectivity from H–Cu(1 1 1) are used to demonstrate that adsorbed hydrogen is removed from the surface in an activated process according to first-order kinetics. The measurements were taken at low coverages with surface temperatures in the range of 210–245 K, where we derive an activation-energy of 64.3 ± 1.3 kJ mol<sup>−1</sup>. The observation allows us to rule out second-order, molecular desorption processes and supports the conclusion that the H atoms are transported from surface to sub-surface sites by an activated process. The results confirm an earlier suggestion that, in the low coverage limit, the sub-surface state for this system is more energetically favourable than other states. In addition, the measurements suggest abstraction processes take place with a probability of (4.3 ± 1.0)s<sub>0</sub>, where s<sub>0</sub> is the initial sticking probability.

Item Type:Articles
Keywords:Absorption kinetics, atom-solid scattering and diffraction, hydrogen atom, copper, molecule-solid reactions, surface structure.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:MacLaren, Professor Donald
Authors: Luo, M.F., MacLaren, D.A., and Allison, W.
Subjects:Q Science > QC Physics
College/School:College of Science and Engineering > School of Physics and Astronomy
University Centres > Glasgow Materials Research Initiative
Journal Name:Surface Science
ISSN:0039-6028
ISSN (Online):1879-2758
Published Online:25 May 2005

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