1D to 3D Dimensional Crossover in the Superconducting Transition of the Quasi-One-Dimensional Carbide Superconductor Sc3CoC4

The transition metal carbide superconductor Sc3CoC4 may represent a new benchmark system of quasi-1D superconducting behavior. We investigate the superconducting transition of a high-quality single crystalline sample by electrical transport experiments. Our data show that the superconductor goes through a complex dimensional crossover below the onset Tc of 4.5 K. First, a quasi-1D fluctuating superconducting state with finite resistance forms in the CoC4 ribbons which are embedded in a Sc matrix in this material. At lower temperature, the transversal Josephson or proximity coupling of neighboring ribbons establishes a 3D bulk superconducting state. This dimensional crossover is very similar to Tl2Mo6Se6, which for a long time has been regarded as the most appropriate model system of a quasi-1D superconductor. Sc3CoC4 appears to be even more in the 1D limit than Tl2Mo6Se6.