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Full-Text Articles in Physics
Fermiology And Superconductivity At High Magnetic Fields In A Completely Organic Cation Radical Salt, J. S. Brooks, V. Williams, E. Choi, D. Graf, M. Tokumoto, S. Uji, F. Zuo, J. Wosnitza, J. A. Schlueter, H. David, Rolf Walter Winter, Gary L. Gard, K. Storr
Fermiology And Superconductivity At High Magnetic Fields In A Completely Organic Cation Radical Salt, J. S. Brooks, V. Williams, E. Choi, D. Graf, M. Tokumoto, S. Uji, F. Zuo, J. Wosnitza, J. A. Schlueter, H. David, Rolf Walter Winter, Gary L. Gard, K. Storr
Chemistry Faculty Publications and Presentations
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 …
Enhanced Magnetic Quantum Oscillations In The Mixed State Of A Two-Dimensional Organic Superconductor, J. Wosnitza, J. Hagel, P. J. Meeson, D. Bintley, J. A. Schlueter, Javid Mohtasham, Rolf Walter Winter, Gary L. Gard
Enhanced Magnetic Quantum Oscillations In The Mixed State Of A Two-Dimensional Organic Superconductor, J. Wosnitza, J. Hagel, P. J. Meeson, D. Bintley, J. A. Schlueter, Javid Mohtasham, Rolf Walter Winter, Gary L. Gard
Chemistry Faculty Publications and Presentations
We report on de Haas–van Alphen (dHvA) oscillations observed in the mixed state of the organic superconductor β″–(BEDT-TTF)₂SF₅CH₂CF₂SO₃ (BEDT-TTF stands for bisethylenedithio-tetrathiafulvalene) utilizing the field-modulation technique and torque magnetometry. At low temperatures (30 mK), the dHvA signal persists down to 1.4 T well below the upper critical field Bc2≈3.6T. Contrary to most theoretical predictions and previous experimental findings, no additional damping of the dHvA-oscillation amplitude, but a reduced damping of the dHvA signal is found. This highly unusual effect might indicate a reduced quasiparticle scattering rate or an additional oscillatory contribution in the superconducting state.
Coherent Vs Incoherent Interlayer Transport In Layered Metals, Gary L. Gard, J. Wosnitza, J. Hagel, J. S. Qualls, J. S. Brooks, E. Balthes, D. Schweitzer, J. A. Schlueter, U. Geiser, Javid Mohtasham, Rolf Walter Winter
Coherent Vs Incoherent Interlayer Transport In Layered Metals, Gary L. Gard, J. Wosnitza, J. Hagel, J. S. Qualls, J. S. Brooks, E. Balthes, D. Schweitzer, J. A. Schlueter, U. Geiser, Javid Mohtasham, Rolf Walter Winter
Chemistry Faculty Publications and Presentations
The magnetic-field, temperature, and angular dependence of the interlayer magnetoresistance of two different quasi-two-dimensional (2D) organic superconductors is reported. For k -BEDT-TTF)₂I₃, where BEDTTTF is bisethylenedithio-tetrathiafulvalene, we find a well-resolved peak in the angle-dependent magnetoresistance at Q590°(field parallel to the layers). This clear-cut proof for the coherent nature of the interlayer transport is absent for β″–(BEDT-TTF)₂SF₅CH₂CF₂SO₃. This and the nonmetallic behavior of the magnetoresistance suggest an incoherent quasiparticle motion for the latter 2D metal.
Orientational Phase Transition In Na_{X}C_{60} (1, T. Yildirim, J. E. Fischer, A. B. Harris, Peter W. Stephens, Dengfa Liu, Laurent Brard, Robert M. Strongin, Amos B. Smith Iii
Orientational Phase Transition In Na_{X}C_{60} (1, T. Yildirim, J. E. Fischer, A. B. Harris, Peter W. Stephens, Dengfa Liu, Laurent Brard, Robert M. Strongin, Amos B. Smith Iii
Chemistry Faculty Publications and Presentations
X-ray diffraction and calorimetry data on cubic NaxC60(1<x60, e.g., Tm(x=1.3)=325 K. The ordered phases are the same as in pure C60: simple cubic, space group Pa3¯, but the orientations in the disordered phase are more restricted. We explain how Na stabilizes the ordered phase to rather high T, while K and Rb do not, in terms of Coulomb interactions between C60 molecules and and Na ions which we calculate from the local charge density of C60.