Carrier doping to (DCNQI)2Li

The alloy systems, (DMe-DCNQI)2Li1−xCux, have been investigated with the aim of controlling of the electronic state by doping of Cu ions into the (spin-) Peierls insulator, (DMe-DCNQI)2Li. Light doping (x<0.3) decreases the (spin-) Peierls transition temperature. In a heavily doped region (x>0.5), the systems are metallic down to at least 1.5K. It is found that the values of (T1T)−1 of 13C-NMR in the high temperature region (T>100K) change systematically with doping concentration, x.