  
|
     
|
The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 3 Issue 3 (1998) pp 301-306
Low frequency dielectric permittivity of quasi-one-dimensional conductor (TMTTF)$_\mathsf 2$Br
F. Nad' (1)(2), P. Monceau (1) (a), J.M. Fabre (3)
(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
Received: 10 October 1997 / Revised: 28 February 1998 / Accepted: 3 March 1998
Abstract: Conductivity and permittivity $\epsilon$ 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, $\epsilon'$, is shown to grow below the temperature $T_\rho$ at which the conductivity is maximum due to charge localization of Mott-Hubbard type. $\epsilon'$ reaches a maximum of 105-106 at 35 K-50 K depending on the samples. Decreasing temperature below $T_\rho$, $\epsilon'$ 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 $\epsilon'$ 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.
PACS. 75.30.Fv Spin-density waves - 77.22.Gm Dielectric loss and relaxation - 71.30.+h Metal-insulator transitions and other electronic transitions
(a) email: monceau@labs.polycnrs-gre.fr
Article in PDF-Format (270 KB)
Online publication: July 14, 1998
LINK Helpdesk
© EDP Sciences, Springer-Verlag 1998