|
|||||
|
|
On the stoichiometry of the organic metal bis(ethylenedioxy)-tetrathiafulvalene chloride |
|
| Authors: | D Beckmann S Wanka J Wosnitza G Goll B Drehmann E Balthes D Schweitzer W Strunz |
| Institution: | Physikalisches Institut, Universit?t Karlsruhe, 76128 Karlsruhe, Germany, DE 3. Physikalisches Institut, Universit?t Stuttgart, 70550 Stuttgart, Germany, DE Anorganisch-Chemisches Institut, Universit?t Heidelberg, 69120 Heidelberg, Germany, DE |
| Abstract: | 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)2 +(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. Received: 16 April 1998 / Revised: 7 July 1998 / Accepted: 9 July 1998 |
| Keywords: | PACS 71 18 +y Fermi surface: calculations and measurements effective mass g factor - 71 20 Rv Polymers and organic compounds |
| 本文献已被 SpringerLink 等数据库收录！ | |