(Pressure, temperature) phase diagram of the quasi-1D 3/4 filled organic salt (o-DMTTF)2Br

The family of quasi-one-dimensional organic salts (o-DMTTF)2X, (X=Cl, Br, I) exhibits regular stacks and a high symmetry (tetragonal) structure which provides a perfect 3/4 band filling system with strong electronic correlations. We report transport measurements, resistivity and thermopower, performed as a function of pressure and/or temperature on (o-DMTTF)2Br which presents all the characteristics of the family. Coupled with data obtained from X-rays diffraction and magnetic susceptibility experiments at ambient pressure, in order to identify the insulating ground states, our data allowed to establish the (pressure, temperature) phase diagram for (o-DMTTF)2Br which differs significantly from those previously reported in other 3/4 filled systems.