KAPPA-(BEDT-TTF)(2)CU[N(CN)(2)]CL - MAGNET AND SUPERCONDUCTOR - HIGH-PRESSURE AND HIGH MAGNETIC-FIELD EXPERIMENTS

In this paper, we have surveyed the current status of an experimental study of kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Cl having revealed that the in terplay between magnetism and superconductivity in this 2-d organic cr ystal is not described by a simple scheme letting the only single phas e to exist at certain fixed pressure and temperature. In contrast, it has been discovered that the magnetism and SC both coexist in the same crystal sample in a wide pressure range, from 1 bar to at least 1.5 k bar. Delicate balance between two competing states depends not only on pressure and temperature but also on the magnetic field treatment and thermal history. Both magnetic and electron transport behavior sugges ts the presence of multiple minima in the free energy possibly associa ted with a modification of molecular arrangement.