Realization and characterization of solid-solid (BEDT-TTF)/iodine C-T composites exhibiting metallic conductivity down to 0.34 K.

It is shown that the organic composite obtained by a direct solid-solid C-T reaction between BEDT-TTF and iodine is metallic from 300 to 0.34 K. There is also a clear manifestation of superconductivity below 5 K, which is confirmed by the particular dependence of the electrical resistivity on magnetic field, up to 30 kG.