Melting of charge order in (DI-DCNQI)2Ag by pressure

Abstract We showed how the charge order in (DI-DCNQI) 2 Ag is melted by pressure, by investigations of the NMR spectra and the resistivity parallel and perpendicular to the conducting c -axis. When the system is pressurized, the second-order-transition temperature of the charge ordering is lowered and the disproportionation ratio is depressed. Under higher pressures, the transition changes into first-order one and eventually it vanishes at 21.6 kbar. At a low-pressure and high-temperature region, temperature dependence of ρ // and ρ ⊥ are contrasting. The melting mechanism of the charge ordering is very likely due to the “dimensional crossover”. Furthermore, in the high-pressure metallic region, curious T 3 dependence of the resistivity is observed, implying unprecedented electron-electron scattering mechanism.