Berlin 2005 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 31: Correlated Electrons - Low-dimensional Materials I
TT 31.3: Vortrag
Dienstag, 8. März 2005, 14:30–14:45, TU H2053
Comparative resistivity studies under hydrostatic pressure on different variants of the organic superconductor κ − (ET)2Cu[N(CN)2]Br — •Christian Strack1, Cemil Akinci1, Bernd Wolf1, Michael Lang1, John Schlueter2, Jochen Wosnitza3, and Dieter Schweitzer4 — 1Physikalisches Institut, J.W. Goethe-Universität Frankfurt, FOR 412 — 2Materials Science Division, Argonne NL, Illinois, USA — 3Institut für Festkörperphysik, TU Dresden — 43. Physikalisches Institut, Universität Stuttgart
Resistivity measurements on four samples of κ −(ET)2Cu[N(CN)2]Br , synthesized by following two different preparation routes, yield strongly sample-dependent ρ(T) profiles. By comparing the interlayer resistivities and their response to hydrostatic pressure we infer: (i) a significant part of the inelastic-scattering contribution, causing the anomalous ρ (T) maximum around 90K, is extrinsic in nature, (ii) the abrupt change in the slope of ρ (T) around T* ≈ 40K is sample independent and most likely marks a second-order phase transition, (iii) the origin of the ρ (T) ∝ AT2 dependence at low temperatures, with a strongly sample dependent coefficient A and range of validity, is different from coherent Fermi-liquid excitations.