Field induced state and hysteresis effect in (DMET-TSeF)/sub 2/AuI/sub 2/

Summary form only given. The magnetoresistance have been measured in (DMET-TSeF)/sub 2/AuI/sub 2/ up to 40 T using pulsed magnetic field at liquid He temperature. (DMET-TSeF)/sub 2/AuI/sub 2/ has quai one-dimensional Fermi surface at room temperature. The existence of Field Induced Spin Density Wave(FISDW) state has been already reported by present authors by the measurement up to 12T at 0.5 K. We report newly observed very large hysteresis effect of magnetoresistance near 26 T in the magnetic field application cycle. It is very similar to the behavior reported in (TMTSF)/sub 2/ClO/sub 4/, but the re-entrant behavior has not been observed in our system. The high field magnetoresistance is very similar to that observed in (TMTSF)/sub 2/PF/sub 6/ under pressure. Therefore it seems that the FISDW state in (DMET-TSeF)/sub 2/AuI/sub 2/ is described by the standard theory.