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Published on October 12, 2007

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Slide1:  Introduction to Nanotechnology, Spring 2004, Mintmire: Lecture 12 Chapter 5. Carbon nanostructures: fullerenes and nanotubes Discovery of carbon fullerenes Molecular beam studies of cluster “building blocks” Exxon group study of carbon clusters Recognition of truncated icosahedral structure of C60 by Smalley group Development of large-scale synthetic methods by Kratschmer and Huffman Definitive experiments to prove existence of C60 Carbon nanotubes intro Handouts Rohlfing, Cox, Kaldor, JCP 81, 3322 (1984). Kroto, et al. Nature 318, 162 (1985). Smalley Nobel Lecture, 1996. Richard Smalley with C60 Slide2:  Prior to 1985 six crystalline forms of carbon were known – Two kinds of graphite, two kinds of diamond, chaoit (discovered in 1968), and carbon (VI) (discovered in 1972) Graphite, fullerenes, and nanotubes are use sp2 bonding. Diamond uses sp3 bonding Slide3:  to mass-spec Slide4:  First reported observation of C60 clusters Rohlfing, Cox, Kaldor, JCP 81, 3322 (1984). Smalley group, Nature 318, 162 (1985) Slide5:  In 1985 a new form was discovered that had the structure of a ball and given the name “buckminsterfullerene” 1996 Nobel Prize in Chemistry awarded to Robert F. Curl, Harold W. Kroto, and Richard E. Smalley ‘for their discovery of fullerenes’ All “fullerene” clusters have even numbers of carbons. Slide6:  In Ancient Greece the regular polyhedra symbolised the different elements, earth, air, fire, water, and the universe. The cube was the symbol of earth and the icosahedron the symbol of water. The form of C60 (and a soccer ball) can be derived from an icosahedron in which the corners have been cut off - a truncated icosahedron. soccer ball truncated icosahedron icosahedron Slide7:  Application of Euler’s theorem to fullerene topology Fullerenes are sp2 bonded, and all “correctly” bonded carbons will have three neighbors. Eulers theorem predicts following relation for “closed” structure (A. J. Haymet, JACS 108, 319 (1984)). Slide8:  Molecular beam techniques did not generate sufficient mass of the fullerenes to carry out standard chemical characterization other than mass spec. Krätschmer and Huffman discovered the carbon-arc technique for making large quantities of C60 and related fullerenes in 1990. Important experiments for characterization Infrared absorption. Theory had predicted four sharp absorption peaks from the high symmetry structure. C13 NMR. Every carbon should be equivalent, giving one set of peaks. Slide9:  IR of C60 Slide12:  Common fullerenes produced Fullerene Crystal:  Fullerene Crystal Crystalline Fullerene fcc structure with lattice constant of 1.417 nm C60-C60 distance – 1.002 nm Melting temperature – 118.0 °C Band gap – 1.7 eV K3C60 Slide14:  Prior to 1985 six crystalline forms of carbon were known – Two kinds of graphite, two kinds of diamond, chaoit (discovered in 1968), and carbon (VI) (discovered in 1972) In 1985 a new form was discovered that had the structure of a ball and given the name “buckminsterfullerene” 1996 Nobel Prize in Chemistry awarded to Robert F. Curl, Harold W. Kroto, and Richard E. Smalley ‘for their discovery of fullerenes’ Krätschmer and Huffman discovered the carbon-arc technique for making large quantities of C60 and related fullerenes in 1990. The race was on. . . Curl Kroto Smalley Discovery of the Fullerenes Slide15:  Carbon Nanotubes: What Are They? Slide16:  2000 Chemistry Nobel Prize 1996 Chemistry Nobel Prize Major research efforts in the 1960’s Slide17:  Carbon nanotubes conventionally grown with high temperature, low pressure techniques using carbon source and metal catalyst particles (1 at % Co/Ni) Rice University group (Smalley) currently using high pressure reactions of carbon monoxide (CO) in presence of metal catalyst particles to produce nanotubes. Price for good quality single walled nanotubes > $1000/g. Slide18:  semiconductor Peierls Distortions: The Nemesis of Synthetic Metals Slide19:  C60 C70 (5,5) nanotube Carbon Nanotubes as Extended Fullerenes Slide20:  Carbon Nanotube Structures from Graphene

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