Hostname: page-component-76fb5796d-skm99 Total loading time: 0 Render date: 2024-04-25T14:51:57.499Z Has data issue: false hasContentIssue false

Formation of Three Dimensional Ni Nanostructures for Large Area Catalysts

Published online by Cambridge University Press:  15 March 2011

J. D. Carey
Affiliation:
Advanced Technology Institute, School of Electronics and Physical Sciences, University of Surrey, Guildford, GU2 7XH.
S. J. Henley
Affiliation:
Advanced Technology Institute, School of Electronics and Physical Sciences, University of Surrey, Guildford, GU2 7XH.
E. Mendoza
Affiliation:
Advanced Technology Institute, School of Electronics and Physical Sciences, University of Surrey, Guildford, GU2 7XH.
C. E. Giusca
Affiliation:
Advanced Technology Institute, School of Electronics and Physical Sciences, University of Surrey, Guildford, GU2 7XH.
A. A. D. T. Adikaari
Affiliation:
Advanced Technology Institute, School of Electronics and Physical Sciences, University of Surrey, Guildford, GU2 7XH.
S. R. P. Silva
Affiliation:
Advanced Technology Institute, School of Electronics and Physical Sciences, University of Surrey, Guildford, GU2 7XH.
Get access

Abstract

The formation of Ni nanostructures to act as catalysts in the growth of carbon nanotubes is reported. The changes in the surface morphology of Ni produced by three methods - thermal evaporation and annealing of thin films, pulsed laser ablation and annealing of Ni, and the use of metal containing macromolecules - have been investigated by atomic force microscopy and scanning electron microscopy. In the case of thermal annealing of thin metal films in the temperature range 300-500°C we observe an increase in the mean diameter of the islands formed, accompanied by a reduction in the mean island density with increasing temperature. We attribute this effect to mass transport of weakly bound individual Ni atoms and/or small island clusters across the surface to form larger isolated islands, in a process similar to Ostwald ripening. Using a pulsed KrF excimer laser for ablation of a Ni target we show that nanometre smooth Ni thin films can be produced provided a sufficient number of laser shots is used. The surface morphology of these smooth films can then be altered by laser annealing to form Ni droplets. It is found that the mean diameter of the Ni droplets depends not only on the initial Ni thickness but also the laser fluence. It is also found that the nanostructuring of the film depends on the presence of an oxide under layer, with a higher fluence required on thinner oxides and no nanostructuring observed on bare Si. Finally, we show that Ni nanostructuring can be formed by suitable annealing of a Ni containing aqueous dendrimer solutions.

Type
Research Article
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Dean, K.A., Chalamala, B.R., Coll, B.F., Xie, Y.W.C. and Jaskie, J.E., New Diam. Frontier Carbon Tech. 12, 165 (2002).Google Scholar
2. Merkulov, V. I., Lowndes, D.H., Wei, Y., Eres, G. and Voelkl, E., Appl. Phys. Lett. 76, 3555 (2000).Google Scholar
3. Henley, S. J., Poa, C. H. P., Adikaari, A. A. D. T, Giusca, C. E., Carey, J. D. and Silva, S. R. P., accepted for publication in Applied Physics Letters.Google Scholar
4. See, for example, www.dendritech.comGoogle Scholar
5. Kaye, G. W. C. and Laby, T. H. in Tables of physical and chemical constants, Longman, London, UK, 15th edition, 1993.Google Scholar
6. Diebold, U., Pan, J.-M. and Madey, T.E., Phys. Rev. B. 47, 3868 (1993).Google Scholar
7. Carey, J. D., Ong, L. L., and Silva, S. R. P., Nanotechnology 14, 1223 (2003).Google Scholar
8. Mendoza, E., Poa, C. H. P., Henley, S. J., Stolojan, V., Chen, G. Y., Giusca, C. E., Carey, J. D. and Silva, S. R. P., unpublished.Google Scholar