Domain walls at the spin-density-wave endpoint of the organic superconductor (TMTSF)2PF6 under pressure

We report a comprehensive investigation of the organic superconductor (TMTSF)(2)PF6 in the vicinity of the endpoint of the spin-density-wave metal phase transition where phase coexistence occurs. At low temperature, the transition of metallic domains toward superconductivity is used to reveal the various textures. In particular, we demonstrate experimentally the existence of one-dimensional and two-dimensional (2D) metallic domains with a crossover from a filamentary superconductivity mostly along the c(star) axis to a 2D superconductivity in the b(')c-plane perpendicular to the most conducting direction. The formation of these domain walls may be related to the proposal of a soliton phase in the vicinity of the critical pressure of the (TMTSF)(2)PF6 phase diagram.