Flux penetration into the strongly two-dimensional organic superconductor κ-(BEDT)2Cu[N(CN)2]Br

We report on measurements of the field of first flux penetration H-p into a single crystal of the organic superconductor kappa-(BEDT)(2)Cu[N(CN)(2)]Br as a function of temperature for applied magnetic fields either parallel or perpendicular to the superconducting planes. The exponential temperature dependence for H-p(T) in both directions indicates the influence of surface barriers, which is particularly strong for H perpendicular to the planes. At 9.5 K, below T-c = 11.3 K, the slope of H-p(T) changes dramatically for both field orientations. (C) 1999 Elsevier Science B.V. All rights reserved.