Reentrant Meissner effect in the organic conductor κ-(BEDT-TTF)2Cu[N(CN)2]Cl under pressure

Abstract
Metallic κ-(BEDT-TTF)2Cu[N(CN2]Cl turns semiconducting and insulating at low temperatures and ambient pressure and enters a ferrimagneticlike state below 20 K. Under hydrostatic pressure (p≃300 bar), previous investigations have shown that the metallic state can be stabilized and that reentrant superconducting behavior can be observed (by means of resistivity measurements) in a rather wide pressure range. By means of dc susceptibility measurements, we show that reentrant volume superconductivity actually exists only in a narrow critical pressure range. In contrast to previously found reentrant superconductors, this material does not contain rare-earth magnetic moments.