Spin-density-wave transition of (TMTSF)(2)PF6 at high magnetic fields - art. no. 052405

The transverse magnetoresistance of the Bechgaard salt (TMTSF)(2)PF6, has b een measured for various pressures, with the field up to 24 T parallel to t he lowest-conductivity direction c*. A quadratic behavior is observed in th e magnetic-field dependence of the spin-density-wave (SDW) transition tempe rature T-SDW. With increasing pressure, T-SDW decreases and the coefficient of the quadratic term increases. These results are consistent with the pre diction of the mean-field theory based on the nesting of the quasi-one-dime nsional Fermi surface. Using a mean-field theory, T-SDW for the perfect nes ting case is estimated as about 16 K. This means that even at ambient press ure where T-SDW is 12 K, the SDW phase of (TMTSF)(2)PF6 is substantially su ppressed by the two dimensionality of the system.