Observation of fast oscillations in the magnetoresistance of the Bechgaardsalt (TMTSF)(2)SbF6

We report on a low-temperature and high-field study of (TMTSF)(2)SbF6 at am bient pressure, where TMTSF stands for tetramethyltetraselenafulvalene. We observe in this salt a single series of fast oscillations in the magnetores istance inside the spin-density-wave state, with oscillation frequency F = 170 T for B parallel to c*. The, angular and thermal behavior of these osci llations has been explored and seems rather similar to that of other salts having octahedral anions(PF6: F= 230 T, AsF6: F= 206 T). However, the frequ ency in SbF6 is surprisingly much lower, a Feature perhaps attributable to anion volume. [S0163-1829(98)06345-0].