Fullerene Nano-Probes

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9522251 Smalley This project addresses one of the grand challenges of nanotechnology: learning how to image and manipulate individual objects on the nanometer scale. Using carbon networks in the form of fullerene nanotubes and wires, this project aims to develop a new generation of probes which connect the macroscopic to the nanoscopic world with chemically specific, atomic precision. Whereas x-ray diffraction and related techniques have long been the basis of our detailed understanding of objects on this atomic length scale, they only work with large numbers of identical copies of the structure arranged in regular crystal lattices. Since the invention and early applications of scanning tunneling microscopy (STM) it has become increasingly clear that it is possible, at least in principle, to break loose from this requirement of needing a crystalline array. It should be possible to image, probe and manipulate individual structures, one by one, on the nanometer scale. Extensions of the idea of STM to other proximate probes such as atomic force microscopy (AFM), and magnetic force microscopy (MFM) have therefore become a major scientific endeavor worldwide. The common feature of all these methods is that they rely on a direct, physical connection between the macroscopic and nanoscopic realms in the form of a tiny "tip" which is scanned with sub-angstrom precision by piezoelectric devices. Most bulk materials are not chemically stable when elongated into probes of width less than 10 nanometers. However, carbon in the form of a graphine sheet is chemically stable in the form of fullerene balls and tubes even when these are less that 1 nm in diameter. This project is aimed at the general development of fullerne tubes as the tips of proximate probes and manipulators. Fullerene nanotubes will be produced both by currently known techniques using carbon arcs and/or catalytic particles and by new methods presently under development. These involve production o f single- and multi-walled nanotubes by laser vaporization of carbon/metal catalyst composite targets in a quartz tube furnace, and controlled growth of mounted "seed crystal" nanotubes in high electric fields. Mounting techniques will be developed to attach individual nanotubes to sharpened platinum electrodes with good electrical contact and reliable mechanical, chemical stability. Electrical and mechanical properties of the individually mounted nanotubes will be measured, including their ability to serve as efficient antennas at optical frequencies and their Q value when used as a nanoscopic cantilever. ***