Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 19: Correlated Electrons: Low-dimensional Materials

TT 19.16: Vortrag

Dienstag, 28. März 2006, 18:00–18:15, HSZ 301

Two-Dimensional Electron-Electron Scattering in the Inherent Conducting Polymer {(CH₃)_0.92ReO₃}_∞ — •R. Miller¹, E.–W. Scheidt¹, G. Eickerling¹, Ch. Helbig¹, R. Herrmann¹, W. Scherer¹, and P. Schwab² — ¹Chemische Physik und Materialwissenschaften, Universität Augsburg, 86159 Augsburg, Germany — ²Theoretische Physik II, Universität Augsburg,

The metal-oxide system polymeric methyltrioxorhenium {(CH₃)_0.92 ReO₃}_∞ (poly-MTO) is a unique representative of an inherent conductive organometallic polymer. In particular the {ReO₂}_∞ planes characterize poly-MTO as a prototype for a purely two-dimensional system. The resistivity data of pure poly-MTO exhibit a crossover from metallic (dρ/dT > 0) to insulating (dρ/dT < 0) behavior at a characteristic temperature T_min≅ 38 K. Above T_min the resistivity ρ(T) is remarkably well described by a two-dimensional electron system. Below T_min an unusual resistivity behavior, similar to that found in doped cuprates, is observed. The resistivity increases as ρ ∼ ln(1/T) before it follows a √T temperature dependence below 2 K. We suggest a crossover from purely two-dimensional charge-carrier diffusion within the {ReO₂}_∞ planes to three-dimensional diffusion at low temperatures in a disorder-enhanced electron-electron interaction scenario (Altshuler-Aronov correction).