He Scattering from Compact Clusters and from Diffusion-Limited Aggregates on Surfaces: Observable Signatures of Structure

Physics – Chemical Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

41 pages, 16 postscript figures. For more details see http://www.fh.huji.ac.il/~dani

Scientific paper

10.1016/0039-6028(94)00828-0

The angular intensity distribution of He beams scattered from compact clusters and from diffusion limited aggregates, epitaxially grown on metal surfaces, is investigated theoretically. The purpose is twofold: to distinguish compact cluster structures from diffusion limited aggregates, and to find observable {\em signatures} that can characterize the compact clusters at the atomic level of detail. To simplify the collision dynamics, the study is carried out in the framework of the sudden approximation, which assumes that momentum changes perpendicular to the surface are large compared with momentum transfer due to surface corrugation. The diffusion limited aggregates on which the scattering calculations were done, were generated by kinetic Monte Carlo simulations. It is demonstrated, by focusing on the example of compact Pt Heptamers, that signatures of structure of compact clusters may indeed be extracted from the scattering distribution. These signatures enable both an experimental distinction between diffusion limited aggregates and compact clusters, and a determination of the cluster structure. The characteristics comprising the signatures are, to varying degrees, the Rainbow, Fraunhofer, specular and constructive interference peaks, all seen in the intensity distribution. It is also shown, how the distribution of adsorbate heights above the metal surface can be obtained by an analysis of the specular peak attenuation. The results contribute to establishing He scattering as a powerful tool in the investigation of surface disorder and epitaxial growth on surfaces, alongside with STM.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

He Scattering from Compact Clusters and from Diffusion-Limited Aggregates on Surfaces: Observable Signatures of Structure does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with He Scattering from Compact Clusters and from Diffusion-Limited Aggregates on Surfaces: Observable Signatures of Structure, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and He Scattering from Compact Clusters and from Diffusion-Limited Aggregates on Surfaces: Observable Signatures of Structure will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-604574

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.