J. Phys. IV France 12 (2002) Pr9-23
Low temperature heterogeneous dynamics in the commensurate ground state of sulfur quasi4 D compounds (TMTTF) 2Br and (TMTTF) 2PF 6J.C. Lasjaunias1, K. Biljakovic2, D. Staresinic2 and P. Monceau1
1 Centre de Recherches sur les Très Basses Températures, CNRS, BP. 766, 38042 Grenoble cedex 9, France
2 Institute of Physics, P.O. Box 304, 70001 Zagreb, Croatia
We report on a study of the slow dynamics of the heat relaxation at very low temperature (T 1 K) in the nominally commensurate ground states of the sulfide compounds (TMTTF) 2Br and (TMTTF) 2PF 6, commensurate SDW - or antifernomagnetic - and spin-Peierls, respectively. For both systems, the long-time dynamics at equilibrium shows a bimodal character, which can be analysed by slow and fast gaussian distributions , separated by one decade in time, which can originate from defects of commensurability.
© EDP Sciences 2002