Superconductivity and field induced states in DMET-TSeF family

The magnetoresistance and magnetization have been measured in (DMET-TSeF)2X (X=AuI2, Au(Br)2, AuCl2, Au(CN)2 and I3.) family. All of them have quasi one-dimensional Fermi surfaces at room temperature. It has been shown that two (AuI2, and I3) of them show superconductivity. We have also found three salts which show field induced spin density wave state, two at ambient pressure, and one under pressure. Another investigation is that I3 salt is superconducting, but does not show FI-SDW nor Shubnikov-de Haas oscillation in spite of the comparatively large magnetoresistance.