Electronic state of (DI-DCNQI)(2)Ag with Cu doping or under pressure

(DI-DCNQI)(2)Ag, which has a quasi-one-dimensional quarter-filled x band, i s a charge-ordered insulator. In the present study, the charge-ordered phas e has been melted in two ways and characterized by the resistivity measurem ents. One is Cu doping into the Ag sites and the other is application of pr essure. As the Cu content is increased, the charge-gapped insulator changes to the nongapped insulator with the variable range hopping behaviour, even tually followed by the metallic phase. When (DI-DCNQI)(2)Ag is pressurized, clear metallic behaviours appear in resistivity above the metal-insulator transition, the temperature of which is decreased at elevated pressures.