Nuclear magnetic resonance of C-60 and fulleride superconductors

The alkali-doped solid materials A(3)C(60) (where A is an alkali metal), which are superconductors with transition temperatures among the highest known apart from the high-T-c cuprates, are among the most exciting outgrowths of the discovery of the family of fullerene molecules. The structural, electronic, and superconducting properties of the alkali fullerides have been subjects of great controversy. In this article the authors review nuclear magnetic resonance (NMR) investigations of the alkali fullerides and of undoped C-60. They show that, although the NMR data certainly provide evidence for unusual static and dynamic structural properties, there is little evidence for unusual normal- and superconducting-state electronic properties, such as strong correlations in the normal state or nonphononic mechanisms of superconductivity.