Comparison of the normal-state properties of κ-(BEDT-TTF)2 Cu(NCS)2 and its deuterated analogue in high magnetic fields and under high hydrostatic pressures
Journal of Physics Condensed Matter 14:26 (2002)
Abstract:
Details of the Fermi-surface topology of deuterated κ(BEDT-TFF)2Cu(NCS)2 (where BEDT-TTF ≡ bis(ethylene-dithio)tetrathiafulvalene) have been measured as a function of pressure, and compared with equivalent measurements of the undeuterated salt. We find that the superconducting transition temperature is much more dramatically suppressed by increasing pressure in the deuterated salt. It is suggested that this is linked to pressure-induced changes in the Fermi-surface topology, which occur more rapidly in the deuterated salt than in the undeuterated salt as the pressure is raised. Our data suggest that the negative isotope effect observed on deuteration is due to small differences in Fermi-surface topology caused by the isotopic substitution.Test for interlayer coherence in a quasi-two-dimensional superconductor.
Phys Rev Lett 88:3 (2002) 037001
Abstract:
Peaks in the magnetoresistivity of the layered superconductor kappa - (BEDT-TTF)2Cu(NCS)(2), measured in fields < or =45 T applied within the layers, show that the Fermi surface is extended in the interlayer direction and enable the interlayer transfer integral (t( perpendicular) approximately 0.04 meV) to be deduced. However, the quasiparticle scattering rate tau(-1) is such that Planck's over 2pi/tau approximately 6t( perpendicular), implying that kappa - (BEDT-TTF)2Cu(NCS)(2) meets the criterion used to identify interlayer incoherence. The applicability of this criterion to anisotropic materials is thus shown to be questionable.Fermi surface studies of quasi-two-dimensional η-Mo4O11
SYNTHETIC METALS 120:1-3 (2001) 783-784
X-ray diffraction study of Co-Cu superlattices
Journal of Physics Condensed Matter 12:30 (2000) 6755-6771