In this paper, we report direct evidence of dynamic structural disorders introduced by quenching a crystal of charge transfer salt κ-(BEDTTTF)2Cu[N(CN)2]Br superconductor from high temperatures to 77 K. The sample quenched from different high temperatures relaxes to an equilibrium state with a single relaxation time constant. The magnitude of the relaxation amplitude is dependent on the quenchi...

2014 We report 1H and 77Se-NMR data on oriented single crystals which establish the magnetic character of the semi-metallic ground state stabilized under high magnetic field in (TMTSF)2ClO4. A similar magnetic state can be stabilized at low temperature in the absence of magnetic field by non-magnetic molecular disorder. At low temperature the spin-lattice relaxation rate does not follow the Kor...

The Fermi surface topology of the organic superconductor λ(BETS)2GaCl4 has been determined using the Shubnikov-de Haas and magnetic breakdown effects and angle-dependent magnetoresistance oscillations. The former experiments were carried out in pulsed fields of up to 60 T, whereas the latter employed quasistatic fields of up to 30 T. All of these data show that the Fermi-surface topology of λ-(...

The properties of a quasi-one-dimensional (quasi-1D) superconductor with an open Fermi surface are expected to be unusual in a magnetic field. On the one hand, the quasi-1D structure of the Fermi surface strongly favors the formation of a non-uniform state (Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) state) in the presence of a magnetic field acting on the electron spins. On the other hand, a magne...

In this paper, we report transport measurements of interlayer magnetoresistance with field parallel and perpendicular to the current direction in an all organic superconductor b9-~BEDT-TTF!2SF5CH2CF2SO3. For HiI , the isothermal magnetoresistance R(H) at low temperatures (T<Tc) displays a peak effect as a function of field. For H'I , R(H) increases monotonically with increasing field. The resul...

We use Josephson plasma resonance (JPR) and DC torque magnetization measurements to investigate the vortex structure and dynamics in the layered organic superconductor -(ET) Cu(NCS) . JPR studies probe the AC response of this extreme type-II superconductor for currents driven along the low conductivity axis. An observed crossover in the magnetic "eld and temperature dependence of the JPR freque...