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TT: Tiefe Temperaturen

TT 30: Postersitzung IV: Kritische Ph
änomene, Quantenstörstellen, niederdimensionale Systeme

TT 30.18: Poster

Thursday, March 11, 2004, 14:30–19:00, Poster A

Electrical conductivity of pure and doped K_0.3MoO₃ single crystals grown by various preparation methods — •S. Yue¹, M. Dressel¹, C. Kuntscher¹, S. van Smaalen², F. Ritter³, and W. Assmus³ — ¹1. Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany — ²Laboratory of Crystallography, University of Bayreuth, 95440 Bayreuth, Germany — ³Physikalisches Institut, Universität Frankfurt, 60054 Frankfurt, Germany

We have studied the temperature dependence of the nonlinear electrical conductivity in a series of pure and doped K_0.3MoO₃ single crystals obtained by different preparation methods (i.e., electrochemistry and temperature-gradient flux techniques). All the pure samples reveal the resistivity anomaly near 180 K and the nonlinear transport, resulting from the Peierls transition and the sliding of the charge-density wave (CDW), respectively. Doping with Rb and W smears out the sharp transition, with the transition temperature decreased. Furthermore, the doping introduces pinning centers which enhance the threshold field for CDW depinning. We will also discuss the temperature dependence of the threshold field for the various samples.