Neutron studies of vibrations in fullerenes

Fullerenes are a remarkable new family of carbon phases in which the carbon atoms form closed cages weakly bounded to each other by van der Waals forces. Unique information about the motions of the molecules as a whole as well as about the atomic on-cage vibrations is obtained from inelastic neutron scattering experiments. The results are interesting both on their own for what they tell us about the binding properties of these compounds and, more generally, for the fact that fullerenes are prototypical examples of molecular solids. In particular, solid has extremely interesting properties as the molecules are more nearly spherical than in any other molecular solid. In the first section of this review, the structure of the most important members of the fullerene family is described. Then, an introduction is given into the field of vibrational properties and the experimental techniques used in this field are briefly presented. This is followed by a detailed discussion of the experimental results and their implications for our understanding of the intramolecular and intermolecular binding forces. This review was received in June 1995