Characterization of the Fermi surface of the organic superconductor β"-(ET)2SF5CH2CF2SO3 by measurements of Shubnikov-de!Haas and angle-dependent magnetoresistance oscillations and by electronic band-structure calculations

The electronic structure of the quasi two-dimensional (2D) organic superconductor beta "-(ET)(2)SF5CH2CF2SO3 was examined by measuring Shubnikov-de Haas (SdH) and angle-dependent magnetoresistance (AMRO) oscillations and by comparing with electronic band-structure calculations. The SdH oscillation frequencies follow the 1/cos theta angular dependence expected for a 2D Fermi surface (FS), and the observed fundamental frequency shows that the 2D FS is 5% of the first Brillouin zone in size. The AMRO data indicate that the shape of the 2D FS is significantly non-circular. The calculated electronic structure has a 2D FS in general agreement with experiment. From the temperature and angular dependence of the SdH amplitude, the cyclotron and band effective masses were estimated to be m(c) = (1.9 +/- 0.05)m(e) and m(b) = (3.90+/-0.05) m(e)/g, where g is the conduction electron g factor and m(e) the free electron mass. The band effective mass is estimated to be m(b)' =1.07 m(e) from the calculated electronic band structure.