Thermodynamics of BEDT-TTF based dimeric salts

The low-temperature electronic properties of (BEDT-TTF)2X are studied by specific heat measurements, especially focusing on the dimeric systems. The β′-(BEDT-TTF)2ICl2 salt shows a similar behavior to the Mott insulating phase in κ-(BEDT-TTF)2X system. The cooling rate dependence of low-temperature specific heat of κ-(d8;BEDT-TTF)2Cu[N(CN)2]Br salt is also studied and appreciable variation in both electronic and lattice specific heat are not observed within the present experiments.