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Structure of Metal Clusters — A High Resolution Electron Microscopy Study of Osmium Clusters on Magnesium Oxide

  • N. J. Long
  • B. C. Gates
  • M. J. Kelley
  • H. H. Lamb

Abstract

High resolution electron microscpy has been used to obtain direct structure images of small aggregates of osmium dispersed on MgO. Some molecular clusters of Os10C(CO)24 2- were deposited directly onto the MgO support and others were synthesised on the support from chloroosmic acid. The electron micrographs show a distribution of aggregate sizes in the latter sample, the larger aggregates having the osmium hexagonal-close-packed structure. Also evident are very small particles ranging in size from one or two atoms up to several atoms, with structures which cannot readily be interpreted as being hep. The Os10 clusters deposited on the support do not have the normal osmium hexagonal-close-packed structure, nor can the images be interpreted as being face-centred-cubic. The images can be interpreted on the basis of the assumption that the clusters have an hexagonal-close-packed structure with a larger c/a ratio. There is a strong interaction between the MgO and the Os aggregates, which are aligned parallel to the MgO {002} planes. The strong interaction could be responsible for the distortion of the cluster away from the normal bulk osmium hexagonal-close-packed structure.

Keywords

Small Aggregate High Resolution Electron Microscopy Os10 Cluster Tetrahydrofuran Solution Aqueous Acetone Solution 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    H.H. Lamb et al., to be published.Google Scholar
  2. 2.
    H.H. Lamb, T.R. Krause and B.C. Gates, J. Chem. Soc. Chem. Commun.: 821 (1986).Google Scholar
  3. 3.
    A.K. Petford-Long, N.J. Long, D.J. Smith, L.R. Wallenberg and J.-O. Bovin, Proc. of this conference: (1986).Google Scholar

Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • N. J. Long
    • 1
  • B. C. Gates
    • 2
  • M. J. Kelley
    • 2
    • 3
  • H. H. Lamb
    • 2
  1. 1.Center for Solid State ScienceArizona State UniversityTempeUSA
  2. 2.Center for Catalytic Science & Technology, Department of Chemical EngineeringUniversity of DelawareNewarkUSA
  3. 3.Engineering Technology Laboratory, Experimental StationE.I. du Pont de Nemours & Co., Inc.WilmingtonUSA

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