BETS-based salts incorporating Fe3+ ions are most interesting candidate systems for the observation of interplay of conductivity and magnetism. Indeed, in λand κ-(BETS)2FeCl4, conduction electrons in the BETS layers do interact with spins localised on the FeCl4 anions. Since the size of non-magnetic GaX4 anion (X = Cl, Br) approximatly equal to that of FeX4, (BETS)2GaX4 system can take the crys...

We present a group theoretical analysis of several classes of organic superconductor. We predict that highly frustrated organic superconductors, such as κ-(ET)(2)Cu(2)(CN)(3) (where ET is BEDT-TTF, bis(ethylene-dithio)tetrathiafulvalene) and β'-[Pd(dmit)(2)](2)X, undergo two superconducting phase transitions, the first from the normal state to a d-wave superconductor and the second to a d+id st...

Mixed-valence (partial charge transfer state) and segregated stacking are the key factors for constructing organic metals. Here, we discuss the ionicity phase diagrams for a variety of charge transfer systems to provide a strategy for the development of functional organic materials (Mott insulator, semiconductor, superconductor, metal, complex isomer, neutral-ionic system, etc.).

Excellent crystals of (TMTSF)(2)AsF(6) (TMTSF, tetramethyltetraselenafulvalene) were employed to obtain x-ray diffraction data for a determination of the electron density distribution in this organic superconductor. Electron density was observed between molecules in a stack of donors of an organic metal and between certain interstack selenium atoms of these donors.

To synthesize a new superconductor which has a critical temperature, Tc, exceeding the room temperature, one needs to know what chemical components to start with. This chapter presents analysis of experimental data which allow one to draw a conclusion about components and the structure of a potential room-temperature superconductor. The two essential components of a roomtemperature superconduct...

Observation of the Fulde-Ferrell-Larkin-Ovchinnikov state in the quasi-two-dimensional organic superconductor κ-(BEDT-TTF) 2 Cu(NCS) 2. Abstract Single crystals of the layered organic type II superconductor, κ-(BEDT-TTF) 2 Cu(NCS) 2 , have been studied in magnetic fields of up to 33 T and at temperatures between 0.5 K and 11 K using a compact differential suscep-tometer. When the magnetic field...

Layered organic superconductors are on the verge of the Mott insulator. We use the Gutzwiller variational method to study a two-dimensional Hubbard model including a spin exchange coupling term as a minimal model for the compounds. The ground state is found to be a Gossamer superconductor at small on-site Coulomb repulsion U and an antiferromagnetic Mott insulator at large U, separated by a fir...

The resonance Raman spectra of (IAuI)~-anions in the organic superconductor Y?-(BEDTTTF)2IAUI as well as in the electrolyte salt n-Bu4AuI2 are investigated. In contrast to /?-(BEDT-TTF)2I3 in the crystals of /?-(BEDT-TTF)2IAuI at low temperature only one Raman line at 120 cm" 1 corresponding to the symmetrical stretching mode of the (IAuI)"-anion is observed. No distinct change in the Raman spe...