The organic salt β″-(BEDT-TTF)2SF5CH2CF2SO3 is a two-dimensional metal with a quarter-filled conduction band. In the metallic state the optical conductivity evidences interaction of the charge carriers with charge-order fluctuations that become stronger as temperature decreases. In the superconducting phase below Tc≈5K, indications of the superconducting gap with 2Δ≈12cm-1 are observed in the optical spectrum, corresponding to 2Δ≈/kB Tc≈3.3. Its temperature and magnetic field dependences are also consistent with predictions by the BCS theory of a weakly coupled superconductor. The conductivity ratio σ11(T = 1:75 K)/σ1(10 K) indicates the opening of the superconducting gap in β″-(BEDT-TTF)2SF5CH2CF2SO3.
|Number of pages||6|
|Journal||Physica Status Solidi (B) Basic Research|
|Publication status||Published - May 2012|