Electronic Properties of Nanoclusters and Nanocluster Arrays
Final rept. 1 May 2000-30 Apr 2003
MINNESOTA UNIV MINNEAPOLIS SCHOOL OF PHYSICS AND ASTRONOMY
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The nature of the evolution with size of conductors from quantum-confined to essentially bulk regime is a fundamental question in science that has important consequences for nanometer-scale electronic systems. This ARO supported program focused on using the technique of buffer layer-assisted growth to produce nanoclusters of Ag and Au that could be used to study the onset of metallic behavior in these metals. The investigations were performed using an ultrahigh vacuum scanning tunneling microscope that can be operated at liquid helium temperatures. The work progressed to the point where the complex scanning tunneling microscopesample preparation system was made operational at low temperature. The growth chamber was configured for buffer layer-assisted growth of clusters, and the method was demonstrated. The sample geometry was a change from the one originally proposed, a second junction using a doped Si membrane barrier, to a planar junction. Simulations of the Coulomb staircase aspect of the measurements, which would serve as baselines for the study of the effects of discrete energy levels, were carried out. The primary goal of the work, the determination of the variation of the electronic density of states with cluster size, was not realized. 15 figures, 7 refs.
- Properties of Metals and Alloys
- Electricity and Magnetism
- Atomic and Molecular Physics and Spectroscopy