DEUTERATED KAPPA-(BEDT-TTF)(2)CU[N(CN)(2)]BR - A SYSTEM ON THE BORDEROF THE SUPERCONDUCTOR-MAGNETIC-INSULATOR TRANSITION

The electronic state of the deuterated salt of the organic system kapp a-(BEDT-TTF)(2)Cu[N(CN)(2)]Br, has been investigated by dc/ac suscepti bility and H-1/C-13 NMR measurements. We found that the system is situ ated in the critical region of the transition between a superconductin g phase with a T-C of similar to 11.5 K and an antiferromagnetic phase with a T-N of 14-15 K. It was also found that the rapid cooling throu gh 80 K drives the superconducting phase into the magnetic phase, that is discussed in the light of the role of disorder near the Mott trans ition.