Slowing down of the relaxational dynamics at the ferroelectric phase transition in one-dimensional (TMTTF)2AsF6

We present measurements of the dielectric response of quasi one-dimensional system (TMTTF)2AsF6 in a wide temperature and frequency range. We provide a thorough characterization of the relaxational dynamics observed close to the ferroelectric-like transition at Tc=100 K. Our measurements, extending up to 100 MHz, reveal a continuous slowing down of the mean relaxation time when approaching Tc from high as well as from low temperatures. The simultaneous critical rise of the dielectric constant and relaxation time point to an explanation of the transition in terms of a classic ferroelectric scenario.