Structure of single-phase superconducting K3C60

Stable superconducting K3C60-phase fullerenes with a 19.3 K transition temperature have been obtained by bulk preparation methods; due to the absence of nonconducting phases, it has proven possible to conduct an active Rietveld analysis of XRD data from the superconducting phase. Attention is presently given to results for the crystal structure of K3C60. It is established that this compound has an fcc cubic structure with well defined stoichiometry. It is expected that these results will furnish the bases for a rigorous description of the compound's normal and superconducting properties. (O.C.)