(DCNQI)(2)CU - VARIETY OF MAGNETISM ARISING FROM P-PI-D INTERACTIONS

Recent advances of our study of magnetic properties of a series of mag netic conductors, Cu salts of DCNQIs, are presented. First, we have fo und weak ferromagnetism in the antiferromagnetically ordered state of Cu spins in the insulating phase. Second, the metal-insulator (M-I) tr ansitions of these systems have been characterized by the abrubt chang e of Cu 3d spins from the itinerant state to the completely localized state, even in the metal-insulator-metal (M-I-M) reentrant system, (DM e-DCNQI-alpha,alpha prime-d(2))(2)Cu. Finally, (DI-DCNQI)(2)Cu is foun d to exhibit enhanced and temperature dependent susceptibility, sugges ting the effect of spin fluctuations of itinerant electrons in a Cu3d narrow band.