Intrinsic vs. extrinsic inelastic scattering contributions in kappa-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br - transport measurements under hydrostatic pressure.
Interlayer-resistivity measurements have been performed on a variety of single crystals of the quasi-two-dimensional organic superconductor {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br. These crystals, which have been synthesized along two somewhat different routes, reveal strongly sample-dependent resistivity profiles: while the majority of samples shows a more or less pronounced {rho}(T) maximum around 90 K with a semiconducting behavior above, some crystals remain metallic at all temperatures T {le} 300 K. In the absence of significant differences in the crystals' structural parameters and chemical compositions, as proved by high-resolution X-ray and electron-probe-microanalysis, these results indicate that real structure phenomena, i.e. disorder and/or defects, may strongly affect the inelastic scattering. Comparative resistivity measurements under He-gas pressure on two crystals with strongly differing {rho}(T) profiles indicate that these additional, sample-dependent scattering contributions are characterized by an extraordinarily strong pressure response which is highly non-monotonous as a function of temperature. No correlations have been found between the strength of these scattering contributions and other characteristic properties such as the glass transition at T{sub g} = 77 K, the temperature T* {approx} 40 K, where the temperature dependence of the resistivity changes rather abruptly, or the superconducting transition temperature T{sub c}.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); German Research Foundation (DFG)
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 914989
- Report Number(s):
- ANL/MSD/JA-58907; TRN: US200817%%51
- Journal Information:
- C. R. Chimie, Vol. 10, Issue Dec. 5, 2006; ISSN 1631-0748
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
Unusual behavior in the upper critical magnetic fields of the ambient-pressure organic superconductor. kappa. -(BEDT-TTF) sub 2 Cu(N(CN) sub 2 )Br (where BEDT-TTF represents bis(ethylenedithio) tetrathiofulvalene)
Anomalous variation of the normal state resistance of {kappa}-(BEDT-TTF){sub 2}CuN(CN){sub 2}Br with temperature and hydrostatic pressure. Small polaron