This study was initiated with support from NSF-DMR 09-71714, and was further carried out under NSF-DMR 02-03532 and completed under NSF-DMR 06-02859. Work at Argonne National Laboratorywas supported by the Office of Basic Energy Sciences, Division of Materials Sciences of the US Department of Energy under contractW-31-109-ENG-38.Work at Portland State University was supported by NSF CHE-9904316.
New Journal of Physics
Magnetoresistance -- Measurement, Organic superconductors, Fermi surfaces
We report specialized interplane magnetoresistance (MR) measurements on the organic superconducting compound β″–(BEDT-TTF)₂SF₅CH₂CF₂SO₃ (where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene) in both the superconducting (Tc ∼ 5K) and normal states versus magnetic field direction. In the normal state, detailed angular-dependent magnetoresistance oscillation (AMRO) studies reveal peculiar features of the Fermi surface topology of this compound, and very high magnetic field studies further support the unusual nature of the electronic structure. In the superconducting state we investigate, through detailedAMRO measurements, the anomalous MR peak that appears within the superconducting field-temperature phase diagram. Our results reveal a direct connection between the superconducting state determined from purely in-plane field, and the vortex lattice produced by the inter-plane magnetic field. We also describe several unique sample rotation instruments used in these high field experiments, including the use of dysprosium pole pieces in combination with a 45 T hybrid magnet to carry out measurements at the highest steady-state resistive magnetic field (47.8 T) yet achieved.
J.S. Brooks, V. Williams, E. Choi, D. Graf, M. Tokumoto, S. Uji, F. Zuo, J. Wosnitza, J. Schlueter, H.D. Davis and R. Winter, “Fermiology and Superconductivity at High-Magnetic Fields in a Completely Organic Charge Transfer Complex,” New Journal of Physics, 8, 255 (2006).