Fullerenes
- PDF / 4,525,423 Bytes
- 44 Pages / 576 x 792 pts Page_size
- 50 Downloads / 241 Views
Fullerenes M. S. Dresselhaus Department of Electrical Engineering and Computer Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
G. Dresselhaus Francis Bitter National Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
P. C. Eklund Department of Physics and Astronomy and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506 (Received 28 December 1992; accepted 14 April 1993)
A review of the structure and properties of fullerenes is presented. Emphasis is given to their behavior as molecular solids. The structure and property modifications produced by alkali-metal doping are summarized, including modification to the electronic structure, lattice modes, transport, and optical properties. Particular emphasis is given to the alkali-metal-doped fullerenes because of their importance as superconductors. A review of the structure and properties of fullerene-based graphene tubules is also given, including a model for their one-dimensional electronic band structure. Potential applications for fullerene-based materials are suggested.
I. INTRODUCTION C6o and related fullerenes have attracted a great deal of interest in recent years because of their unusual properties. Fullerenes are of broadly based interest to scientists in many fields: to physicists for their relatively high Tc superconductivity (33 K), the fivefold local symmetry of the icosahedral fullerenes and the quasi-ID behavior of fullerene-related nanotubules; to chemists for the large family of new compounds that can be prepared from fullerenes; to earth scientists because of the very old age of shungite, a mineral deposit that contains a high concentration of fullerenes; and to materials scientists as representing a source of monodisperse nanostructures that can be assembled in film and crystal form and whose properties can be controlled by doping and intercalation. There are a number of theoretical suggestions for icosahedral molecules that predated their experimental identification by many decades, including the very early work of Tisza1 who considered the point group symmetry for icosahedral molecules and Osawa2 who suggested that an icosahedral C6o molecule (see Fig. 1) might be stable chemically. Early Russian workers showed by Hiickel calculations that C6o should have a large electronic gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO).3'4 These early theoretical suggestions for icosahedral Ceo were not widely appreciated, and 2054
J. Mater. Res., Vol. 8, No. 8, Aug 1993
some of this literature was Only rediscovered after the experimental work of Kroto and co-workers in the middle 1980's 5 established the stability of the C60 molecule in the gas phase. Concurrently, astrophysicists were trying to identify some unusual IR emissions of interstellar dust from carbon stars, and this work also suggested the possibility of larger carbon clusters. 6 " 8 Hare and Kroto have argu
Data Loading...
