Numéro |
J. Phys. IV France
Volume 131, December 2005
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Page(s) | 55 - 58 | |
DOI | https://doi.org/10.1051/jp4:2005131011 | |
Publié en ligne | 18 janvier 2006 |
S. Brazovskii, P. Monceau and N. Kirova
J. Phys. IV France 131 (2005) 55-58
DOI: 10.1051/jp4:2005131011
Mid-infrared response of charge-ordered quasi-1D organic conductors (TMTTF)2X
M. Dumm, M. Abaker and M. DresselPhysikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany
Abstract
We investigated the temperature dependence of the charge
disproportionation in the charge ordered quasi one-dimensional
conductors (TMTTF)2AsF6 and (TMTTF)2PF6 by
infrared spectroscopy. In the mid-infrared, we observed a splitting
of characteristic vibronic modes below the charge-order transition
which can be directly linked to the charge disproportionation on the
molecules. From our analysis of these modes we extracted the
temperature dependence of the charge disproportionation which is
much stronger in (TMTTF)2AsF6 compared to
(TMTTF)2PF6. The charge disproportionation is only weakly
affected by the spin-Peierls transition in the AsF6 salts and
remains basically unchanged in the PF6 salts. Therefore, our
data confirm that the spin-Peierls and charge-ordered ground state
coexist at low temperatures.
© EDP Sciences 2005