Proton relaxation in the organic superconductor (BEDT-TTF)2Cu(NCS)2

Abstract

The origin of the nonexponentiallity of the proton spin-lattice relaxation in the organic superconductor (BEDT-TTF)2Cu(NCS)2 is clarified. In fine powders the nonexponentiallity results from localized paramagnetic centers whose concentration is nonuniform over the powder sample. In coarse grains at low temperatures it is due to finite penetration of the rf-field into the conducting grains.