REENTRANT SUPERCONDUCTIVITY IN KAPPA-(BEDT-TTF)2CU[N(CN)2]CL AND ITS PRESSURE PHASE-DIAGRAM

Electrical resistivity and magnetization measurements reveal that kapp a-(BEDTTTF)2Cu[N(CN)2]Cl exhibits reentrant superconductivity (reporte d here for the first time for an organic solid) in a wide pressure reg ion. The behavior based on the subtle balance between superconductivit y and resistive (magnetic) phase is affected dramatically by thermal h istory. The low temperature state below 300 bar is of inhomogeneous mi xture of superconductive and non-metallic phases, while the phase in h igher pressure region can be single: rich variety of phases are found in pressure phase diagram.