Superconductivity and fluctuating magnetism in quasi-two-dimensional {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br probed with implanted muons.
A muon-spin relaxation ({mu}{sup +}SR) investigation is presented for the molecular superconductor {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br. Evidence is found for low-temperature phase separation throughout the bulk of the material, with only a fraction of the sample showing a superconducting signal, even for slow cooling. Rapid cooling reduces the superconducting fraction still further. For the superconducting phase, the in-plane penetration depth is measured to be {lambda}{parallel} = 0.47(1) {micro}m, and evidence is seen for a vortex decoupling transition in applied fields above 40 mT. The magnetic fluctuations in the normal state produce a precipitous drop in relaxation rate above 100 K, and we discuss the possible causes for the unusual relaxation that we observe for T > T{sub c}.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); Engineering and Physical Sciences Research Council (EPSRC)
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 1004042
- Report Number(s):
- ANL/MSD/JA-67431; TRN: US1100575
- Journal Information:
- Phys. Rev. B, Vol. 83, Issue Jan. 19, 2011
- Country of Publication:
- United States
- Language:
- ENGLISH
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