Enhanced Critical Temperature in a Dual-Layered Molecular Superconductor

Single-crystal X-ray diffraction has shown that the high-critical-temperature (Tc) phase of the filamentary molecular superconductor (BEDT-TTF)2Ag(CF3)4(1,1,2-trichloroethane) [BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene] contains layers of BEDT-TTF radical cations with alternating κ- and α′-type packing motifs. This molecule-based superconductor with dual BEDT-TTF packing motifs has a Tc five times higher than that of its polymorph that contains only κ-type packing.