Fermiology and superconductivity studies on the non-tetrachalcogenafulvalene-structured organic superconductor β-(BDA-TTP)2SbF6 -: art. no. 174511

The quantum oscillatory effect and superconductivity in a non-tetrachalcogenafulvalene (TCF) -structure-based organic superconductor beta-(BDA-TTP)(2)SbF6 are studied. Here the Shubnikov-de Haas effect and angular-dependent magnetoresistance oscillations are observed. The oscillation frequency associated with a cylindrical Fermi surface is found to be about 4050 T, which is also verified by a tunnel diode oscillator (TDO) measurement. The upper critical-field (H-c2) measurement in a tilted magnetic field and the TDO measurement in the mixed state reveal a highly anisotropic superconducting nature in this material. We compare the physical properties of beta-(BDA-TTP)(2)SbF6 with typical TCF-structure-based quasi-two-dimensional organic conductors. A notable feature of the beta-(BDA-TTP)(2)SbF6 superconductor is a large value of effective cyclotron mass m(c)(*)=12.4+/-1.1m(e), which is the largest yet found in an organic superconductor. A possible origin of the enhanced effective mass and its relation to the superconductivity are briefly discussed.