ALLOYED DEUTERATED COPPER-DCNQI SALTS - PHASE-TRANSITIONS AND REENTRYOF CONDUCTIVITY, GIANT HYSTERESIS EFFECTS, AND COEXISTENCE OF METALLIC AND SEMICONDUCTING MODES

The copper salts of DCNQI (N,N'-dicyanoquinonediimine). quasi-three-di mensional system, show three possible modes of behavior at low tempera tures: they remain metallic, they undergo a phase transition, or they have a suppressed phase transition, as is the case for alloyed copper salts. Deuteration of these salts can change their behavior. Alloyed d euterated copper-DCNQI salts have been investigated using electron spi n resonance, susceptibility, and conductivity measurements, revealing a reduction of the phase transition temperature-with hysteresis-and re entry effects in the conductivity.