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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 1 Issue 4 (1998) pp 419-428
Concerning the first-order phase transition in the low-dimensional organic superconductor $\mathsf{ (BEDO{-}TTF)_2ReO_4\cdot H_2O}$. Crystal and electronic band structures below the phase transition $\mathsf{ (T = 170 K)}$
S.S. Khasanov (1), B.Z. Narymbetov (1), L.V. Zorina (1), L.P. Rozenberg (1), R.P. Shibaeva (1) (a), N.D. Kushch (2), E.B. Yagubskii (2) (b), R. Rousseau (3), E. Canadell (3) (c)
(1) Institute of Solid State Physics, Russian Academy of Sciences, 142432 Chernogolovka, MD, Russia
(2) Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences, 142432 Chernogolovka, MD, Russia
(3) Institut de Ciencia de Materials de Barcelona (CSIC), Campus de la U.A.B., 08193 Bellaterra, Spain
Received: 4 September 1997 / Received in final form: 2 December 1997 / Accepted: 3 December 1997
Abstract: The effect of the first-order phase transition occurring around 220 K on the crystal and electronic structure of the molecular superconductor (BEDO-TTF)${\rm _2ReO_4\cdot H_2O}$ has been studied. The crystal structure at 170 K has been determined and it is found that the main structural change resulting from the phase transition is connected with a rotation of the ${\rm ReO_4^-}$ anions. This rotation leads to changes in the S$\cdots$S and S$\cdots$O intermolecular contacts within the BEDO-TTF donor layers. How these structural changes affect the electronic structure of the salt is studied by comparing the transfer integrals for the different donor$\cdots$donor intermolecular interactions calculated for the room temperature and 170 K crystal structures. It is shown that Fermi surfaces for the 170 K and room temperature structures are very similar, do not exhibit nesting properties, and can be described as resulting from the hybridization of superposing ellipses.
PACS. 61.66.Hq Organic compounds - 74.70.Kn Organic superconductors
(a) email: shibaeva@issp.ac.ru
(b) email: yagubski@icp.ac.ru
(c) email: canadell@zas.qf.ub.es
Online publication: March 19, 1998
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