Europhys. Lett.
Volume 73, Number 4, February 2006
Page(s) 567 - 573
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 13 January 2006
Europhys. Lett., 73 (4), pp. 567-573 (2006)
DOI: 10.1209/epl/i2005-10443-1

Divergence of the relaxation time in the vicinity of the ferroelectric charge-ordered phase transition in $\chem{(TMTTF)_2AsF_6}$

F. Nad1, 2, P. Monceau2, L. Kaboub3 and J. M. Fabre3

1  Institute of Radio-Engineering and Electronics, Russian Academy of Sciences Mokhovaya 11, 103907 Moscow, Russia
2  Centre de Recherches sur les Très Basses Températures, CNRS 25 rue des Martyrs, BP 166, 38042 Grenoble cedex 9, France
3  Laboratoire de Chimie Structurale Organique, Université de Montpellier 34095 Montpellier cedex, France

received 16 June 2005; accepted in final form 3 January 2006
published online 13 January 2006

A sharp maximum in the temperature dependence of the relaxation time obtained from low-frequency permittivity measurements is found in the quasi-one-dimensional conductor $\chem{(TMTTF)_2AsF_6}$ at a temperature of 101$\un{K}$. This maximum is associated with the second-order phase transition into a charge-ordered state of Wigner type. The character of relaxation processes above and below this phase transition is discussed.

71.30.+h - Metal-insulator transitions and other electronic transitions.
71.45.Lr - Charge-density-wave systems.
77.80.Bh - Phase transitions and Curie point.

© EDP Sciences 2006