From semiconductor-semiconductor transition (42 K) to the highest-Tc organic superconductor, κ-(ET)2Cu[N(CN)2]Cl (Tc = 12.5 K)

The discovery of an organic superconductor with the highest transition temperature (125 K) recorded following the suppression of a semiconductor-semiconductor transition (42 K) is reported. The reported compound is a kappa-phase superconductor, kappa-(ET){sub 2}Cu(N(CN){sub 2})Cl, which is isostructural with the recently prepared ambient-pressure superconductor kappa-(ET){sub 2}Cu(N(CN){sub 2})Br with a transition temperature of 11.5 K that has been previously reported. Band electronic structural calculations show the newly discovered compound to be a two-dimensional metal. 15 refs., 2 figs.