HIGH-T-C SUPERCONDUCTIVITY THEORY FOR FULLERENES

For fullerenes, the topmost valence band is the t(1u) band which is pa rtially filled for M(3)C(60) (M=K, Rb or Cs). The t(1u) band widths an d energies depend on intercage distances and interactions between adja cent C-60 cages. These interactions are modulated by lattice vibration s or phonons. The modulation provides coupling of t(1u) electrons to p honons. From available experimental data, relevant coupling parameters have been evaluated. Following BCS theory, a universal curve of trans ition temperature T-c vs. lattice constant have been obtained. This cu rve agrees well with experimental data. Theoretical isotope effect exp onential (similar to 0.4) also agrees well with experimental value (si milar to 0.3). The theory is also consistent with absence of high-temp erature superconductivity in C-60, M(4)C(60), M(6)C(60) and graphite i ntercalation compounds.