Fullerenes dissolve gold in a sequence of phase transformations

We present the observation of gold intercalation into the polycrystalline C -60 and C-70 thin films by a dry electrolysis of the electrode, detected by in situ and space resolved conductivity measurements at different temperat ures and applied voltages. The time resistivity behavior is described on th e basis of electric field stimulated diffusion of metal ions from the conta ct into the interstitials of crystal lattice. The resistivity minima corres pond to a local formation of Au3C60 and respectively Au1C70 and Au4C70 phas es. In contrast to AuxC60, the AuxC70 phases are stable only in the applied electric field.