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TT: Fachverband Tiefe Temperaturen
TT 44: Poster Session Correlated Electrons
TT 44.57: Poster
Thursday, March 17, 2011, 10:00–13:00, P1
Quasi-1D Transport Measurements on (TMTTF)2X under Hydrostatic Pressure — •Karl Schrem, Eva Rose, Gabi Untereiner, and Martin Dressel — 1. Physikalisches Institut, Universität Stuttgart
The charge transfer salts (TMTTF)2X and (TMTSF)2X are model compounds for low-dimensional strongly correlated electron systems where the interplay of electronic, spin and lattice degrees of freedom together with changes of dimensionality result in a rich temperature-pressure phase diagram. All (TMTTF)2X compounds are located on the quasi-one dimensional part of the phase diagram and develop a charge-ordered phase at different temperatures TCO, except (TMTTF)2ClO4 and (TMTTF)2Br. In the group with non-centrosymmetric anions (X=ClO4, BF4, ReO4) one can observe anion ordering for T < TAO, resulting in a doubling of the unit cell. The different phases can easily be tuned both by chemical and hydrostatic pressure. We investigated several non-centrosymmetic compounds by carrying out electrical transport measurements under hydrostatic pressure up to 12 kbar and down to 4.2 K along different crystal axis. Our measurements show the changes in band width and dimensionality by pressure and its consequences on correlation effects, such as charge order. The shift of TAO and the modification of the related transport characteristics stress the importance of the coupling between electronic system and the lattice.