Universality of the Intermediate Phase and High-Temperature Superconductivity in C60

Abstract

With the discovery of Tc s over 100K, continuously biased hole-doped semiconductive C60+y has joined the family of high-temperature superconductors (HTSC) previously dominated by the ceramic cuprates. The phase diagrams of these two quite different materials are remarkably similar, despite the absence from undoped C60+y of magnetic order. This supports percolative models of HTSC based on strong electron-phonon interactions. These models explain observed fine structure in the C60+y phase diagrams, and furthermore suggest novel paths to still higher Tc s.