Superconductivity in K-doped p-sexiphenyl

Organic compounds with π-electron network present great potential to be high temperature superconductors. Here we report the finding of superconductivity at a critical temperature of 7.4 K in para-sexiphenyl with the intercalation of potassium. By removing strong ferromagnetic background, the Messiner effect can be clrealy observed from the M-H plots. The obvious bipolaronic character is detected from Raman scattering measurements. Amorphous phase is found in the sample from X-ray diffraction patterns.