Universality of the intermediate phase and high-temperature superconductivity in C-60

With the discovery of T. values over 100 K, continuously biased hole-doped semiconductive C-60(+y) has joined the family of high-temperature superconductors (HTSCs) previously dominated by the ceramic cuprates. The phase diagrams of these two quite different materials are remarkably similar, despite the absence from undoped C-60(+y) of magnetic order. This supports percolative models of HTSCs based on strong electron-phonon interactions. These models explain observed fine structure in the C-60(+y) phase diagrams, and furthermore suggest novel paths to still higher T-c values.