Heat conduction in kappa-(BEDT-TTF)(2)X superconductors

We present the first study of thermal conductivity of a quasi two dimension al organic superconductor. kappa-(BEDT-TTF)(2)Cu(NCS)(2) presents features which have already been detected in the high T-c cuprates. Notably we obser ved an increase of the thermal conductivity at the superconducting transiti on which is suppressed by a moderate magnetic field. At low temperatures we clearly resolved a residual electronic contribution close to the universal limit value which is consistent with an anisotropic pairings with lines of nodes in the superconducting gap function.