Pressure dependence of the SDW transition in (TMTTF)2Br

We investigated the pressure dependence of the resistivity in (TMTTF) 2 Br, applying with pressure up to 1.2GPa. At ambient pressure the resistance shows the kink structure at 18K where the spin susceptibility starts to decrease, despite the AF transition occurs at 14K. With increasing pressure, the peak of the derivative of the resistance appears 4-8K above the AF transition. It's suggested to be the new phase transition above the AF transition. Above 0.5GPa, the pressure dependence of T SDW is consistent with the prediction of the mean field theory.