Electrical conductivities of MOTT salts

The temperature dependences of electrical conductivities were measured for several ion-radical salts of MOTT [4,5-methylenedithio-4′,5′-(2-oxatrimethylenedithio)tetrathiafulvalene]. MOTT salts containing octahedral anions exhibited metallic behavior down to 20–50 K. The metal-nonmetal transition of MOTT2AsF6 was suppressed by pressurization. The X-ray crystallographic analyses and band calculations based on the crystal structures clarified the quasi-one-dimensional nature of MOTT2AsF6 and MOTT2SbF6.