Alloyed deuterated copper-DCNQI salts: Phase transitions and reentry of conductivity, giant hysteresis effects, and coexistence of metallic and semiconducting modes


  • We thank W. Bietsch and H. Wachtel for technical assistance, M. Jopp and W. Tuffentsammer for growing the crystals and E. Brücher for the susceptibility measurements. This work was supported by the Deutsche Forschungsgemeinschaft (SFB 329).


The copper salts of DCNQI (N, N'-dicyanoquinonediimine), quasi-three-dimensional systems, show three possible modes of behavior at low temperatures: 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 deuterated copper-DCNQI salts have been investigated using electron spin resonance, susceptibility, and conductivity measurements, revealing a reduction of the phase transition temperature[BOND]with hystersis[BOND]and reentry effects in the conductivity.