Eur. Phys. J. B 3, 301-306 (1998)
https://doi.org/10.1007/s100510050316

Low frequency dielectric permittivity of quasi-one-dimensional conductor (TMTTF)2Br

¹ Centre de Recherches sur les Très Basses Températures, associé à l'Université Joseph Fourier, CNRS, BP 166, 38042 Grenoble Cedex 9, France
² Institut of Radioengineering and Electronics, Russian Academy of Sciences, Mokhovaya 11, 103907 Moscow, Russia
³ Laboratoire de Chimie Structurale Organique, Université de Montpellier, 34095 Montpellier Cedex 5, France

Corresponding author: ^a monceau@labs.polycnrs-gre.fr

Received: 10 October 1997
Revised: 28 February 1998
Accepted: 3 March 1998
Published online: 15 June 1998

Abstract

Conductivity and permittivity ϵ of the organic transfer salt (TMTTF)₂Br have been measured at low frequencies (10²-10⁷ Hz) between room temperature down to 4 K. The real part of the permittivity, , is shown to grow below the temperature at which the conductivity is maximum due to charge localization of Mott-Hubbard type. reaches a maximum of 10⁵-10⁶ at 35 K-50 K depending on the samples. Decreasing temperature below , sharply decreases down to helium temperature through the antiferromagnetic phase transition at T _N = 15 K. We explain the magnitude, the temperature and frequency dependence of as resulting from short range charge density wave states in the temperature range where charge localization occurs. This interpretation is supported by recent X-ray scattering measurements.