https://doi.org/10.1007/s100510050557
On the stoichiometry of the organic metal bis(ethylenedioxy)-tetrathiafulvalene chloride
1
Physikalisches Institut, Universität Karlsruhe, 76128
Karlsruhe, Germany
2
Grenoble High Magnetic Field Laboratory, MPI-Festkörperforschung
and CNRS, 38042 Grenoble, France
3
3. Physikalisches Institut, Universität Stuttgart, 70550
Stuttgart, Germany
4
Anorganisch-Chemisches Institut, Universität Heidelberg, 69120
Heidelberg, Germany
Corresponding author: a Jochen.Wosnitza@phys.uni-karlsruhe.de
Received:
16
April
1998
Revised:
7
July
1998
Accepted:
9
July
1998
Published online: 15 December 1998
We report on Shubnikov–de Haas and de Haas–van Alphen measurements
of an organic metal based on the molecular donor
bis(ethylenedioxy)-tetrathiavulvalene (= BEDO-TTF) and the anion
Cl- with H2O molecules. The observed single oscillation frequency
perfectly follows the two-dimensional dependence 
with 
T. The Fermi-surface area of
of the first Brillouin zone proves a quarter-filled
band, i.e., a 2:1 stoichiometry of the BEDO-TTF donor with respect to
the anion. The apparent discrepancy to X-ray data which give a 1:1
ratio between BEDO-TTF and Cl- is understood by
replacement of H2O molecules with (H3O)+ ions. The proposed
stoichiometry therefore is (BEDO-TTF)
(H5O2)+(Cl-)2.
The cyclotron effective mass is 
when deduced from the temperature dependence of the fundamental oscillation
amplitude, but strongly reduced when extracted from higher harmonics.
This and the strong harmonic content of the oscillations signals an
influence of the two-dimensional electronic structure and can be
qualitatively understood by applying the concept of magnetic interaction
to the effect of the oscillatory chemical potential.
PACS: 71.18.+y – Fermi surface: calculations and measurements; effective mass, g factor / 71.20.Rv – Polymers and organic compounds
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998
