Low frequency dielectric relaxation of spin density wave in the Bechgaard salt (TMTSF)2PF6

We report the main features of the low frequency dielectric relaxation of the spin density wave (SDW) in (TMTSF)2PF6. We show that it is somewhat broader than the Debye and its shape does not change with temperature. The central relaxation time τ0 is thermally activated in a manner similar to the d.c. conductivity (Δfc ~ 20K) and saturates below Tco≅ = 1.9K. At the same temperature the power law which governs the relaxation strength versus τ0 behaviour ceases to be valid.