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Colloquia

ics Colloquium
Friday, September 13, 2002
4:00 PM
Physics Building, Room 204
Note special time.
Prof. Puru Jena [Host: Joseph Poon/Louis Bloomfield]
Virginia Commonwealth University
"The Role of Clusters in the Design of Nano-Scale Systems"
ABSTRACT:
Atomic clusters consisting of a few to a few thousand atoms constitute a new phase of matter intermediate between atoms and solids. Unlike conventional nanostructured materials, the size and composition of these clusters can be controlled one atom at a time. The properties of such clusters brought about by their large surface-to-volume ratio, unique geometry, low dimensionality and reduced coordination, exhibit novel behavior quite unlike that in the bulk. For example, metallic elements can be made to form ionic bonds while nonmagnetic and anti-ferromagnetic materials can become ferromagnetic or ferrimagnetic. This talk will introduce the principles for designing these clusters and discuss a concept where clusters can be viewed as super-atoms - adding a third dimension to the periodic table. Recent experimental evidence to support this idea will be presented. Examples of cluster assembled materials will include high-energetic materials involving Al(MnO4)3, alkali metal clusters isolated in zeolites, transition metal clusters supported on organic and metallic substrates, and manganese-oxide clusters passivated by acetate ligands. Ultimately the properties of crystals composed of clusters as the building blocks will be discussed. It is hoped that the synergy between theory and experiment will lead to the synthesis of cluster assembled materials with unique and tailored properties, thus creating new opportunities in materials science at the dawn of the new millennium.

To add a speaker, send an email to phys-speakers@Virginia.EDU. Please include the seminar type (e.g. Colloquia), date, name of the speaker, title of talk, and an abstract (if available).