LOW-FREQUENCY PERMITTIVITY OF SPIN-DENSITY-WAVE IN (TMTSF)(2)PF6 AT LOW-TEMPERATURES

Conductivity and permittivity epsilon of(TMTSF)(2)PF6 have been measur ed at low frequencies of (10(2)-10(7) Hz) at low temperatures below th e spin-density wave (SDW) transition temperature T-p. The temperature dependence of the conductivity shows a deviation from thermally activa ted behavior at T less than or equal to 2 K and a transition to hoppin g type conductivity. The frequency dependences of Re epsilon = epsilon ' and Im epsilon = epsilon '' show log f scaling as it is typical for various disordered systems. The temperature dependence of epsilon' exh ibits a maximum which shifts to lower temperatures with decreasing fre quency. The temperature variation of the relaxation time has two branc hes : with decreasing temperature the long-time branch diverges near s ome temperature (alpha relaxation), while the short-time branch increa ses monotonically (beta relaxation). The results obtained provide evid ence for a transition of the SDW conductor into a glassy-like state at low temperatures similarly to the case of charge density waves.