Peierls Instability and Charge-Density-Wave Transport in Fluoranthene and Perylene Radical Cation Salts |
| W. Brütting and W. Riess Physikalisches Institut and Bayreuther Institut für Makromolekülforschung (BIMF), Universität Bayreuth, D-95440 Bayreuth, Germany |
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| Fluoranthene and perylene radical cation salts are quasi-one-dimensional conductors, which show a Peierls transition to a charge-density-wave ground state. Radical cation salts with different stoichiometries composed of the aromatic donor molecules fluoranthene (Fa = C16H10) or perylene (Per = C20H12) and the counterion X¯ = PF¯6 were investigated. We find that the temperature dependence of the electrical conductivity and the properties in the charge-density-wave ground state strongly depend on the composition of the crystals. When fluoranthene is replaced by perylene, the Peierls transition is shifted from 180 K to 120 K and the ground state energy gap decreases from values of 120-180 meV to 60-80 meV. In the charge-density-wave ground state the threshold field for nonlinear conductivity varies between 0.1 and 1 V/cm for different systems. Our results indicate that disorder, three-dimensional coupling and commensurability effects play an important role for the transport properties of these systems. |
| DOI: 10.12693/APhysPolA.87.785 PACS numbers: 71.45.Lr, 71.30.+h, 72.10.Bg, 72.80.Le |