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PV: Plenarvorträge

PV V

PV V: Plenary Talk

Wednesday, March 24, 2004, 09:00–09:45, Aula

Clusters as precursurs of nano-objects — •Catherine Bréchignac — Laboratoire Aimé Cotton CNRS, Orsay, Frankreich

Investigations of clusters made up from a few atoms, to several thousand atoms, from one to several tens of nanometers in diameter open new avenues for explorations of the physical factors and principles that underlie the transition from atomic and molecular regime to the condensed phase regime. The transition of matter from atomic to the solid state implies changes of organization which turn out to be more subtle and complex than was aticipated from scaling law.

The methods of synthesizing small particles based on agglomerating atoms or molecules, form objects whose size is comparable to the nanostructures obtained by sculpting the material microscopically, by nano-lithography or nano-engraving for example. When it is isolated the cluster can be considered as a prototype of small finite system and constitute a tool for exploring the unexpected and unique properties of small finite objects, where each atom counts. When interacting they offer the possibility of use as elementary building blocks for new nano-architectures, making possible the control of matter at nanometer scale. In the light of several examples this paper will discuss the issues of the electronic excitation, the stability, the reactivity of metallic clusters as well as the new architectures made by self-organization of deposited clusters.