Self-organization of charge under pressure in the organic conductorC. Colin1, P. Auban-Senzier1, C. R. Pasquier1 and K. Bechgaard2
1 Laboratoire de Physique des Solides, UMR8502 - Bat. 510, Centre Universitaire F-91405 Orsay Cédex, France
2 Department of Chemistry, H.C. Oersted Institute - Univeristetsparken 5 DK-2100, Copenhagen, Denmark
received 29 March 2006; accepted 24 May 2006
published online 14 June 2006
presents a phase coexistence between two anion orderings defined by their wave vectors q2=(1/2,1/2,1/2) and q3=(0,1/2,1/2) in a wide range of pressure (8-11) and temperature. From the determination of the anisotropy of the conductivity and the superconducting transitions in this regime we were able to extract the texture which results from a self-organization of the orientations of the anions in the sample. At the lowest pressures, the metallic parts, related to the q3 order, form droplets elongated along the a-axis embedded in the semiconducting matrix associated with the q2 order. Above 10, filaments along the a-axis extend from one end of the sample to the other nearly up to the end of the coexistence regime. A mapping of the system into an anisotropic Ising lattice is satisfactory to analyze the data.
74.70.Kn - Organic superconductors.
72.60.+g - Mixed conductivity and conductivity transitions.
72.80.Le - Polymers; organic compounds (including organic semiconductors).
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