Superconductivity in Metal-mixed Ion-Implanted Polymer Films
  Ion-implantation of normally insulating polymers offers an alternative to depositing conjugated organics onto plastic films to make electronic circuits. We used a 50 keV nitrogen ion beam to mix a thin 10 nm Sn/Sb alloy film into the sub-surface of polyetheretherketone (PEEK) and report the low temperature properties of this material. We observed metallic behavior, and the onset of superconductivity below 3 K. There are strong indications that the superconductivity does not result from a residual thin-film of alloy, but instead from a network of alloy grains coupled via a weakly conducting, ion-beam carbonized polymer matrix. 
A.P. Micolich, E. Tavenner, B.J. Powell, A.R. Hamilton, M.T. Curry,   R.E. Giedd and P. Meredith