Eur. Phys. J. E 8, 269-274 (2002)
DOI: 10.1140/epje/i2001-10093-7
Dynamical precursor of nematic order in a dense fluid of hard ellipsoids of revolution
Th. Theenhaus1, M.P. Allen2, M. Letz3, A. Latz4 and R. Schilling11 Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, D-55099 Mainz, Germany
2 H.H. Wills Physics Laboratory, University of Bristol, Royal Fort, Tyndall Avenue, Bristol BS8 1TL, UK
3 Schott Glas, Research and Developement, Hattenbergstr. 10, D-55014 Mainz, Germany
4 Institut für Physik, TU - Chemnitz, D-09107 Chemnitz, Germany
Latz@itwm.fhg.de
(Received 19 September 2001 and Received in final form 19 March 2002)
Abstract
We investigate hard ellipsoids of revolution in a parameter regime
where no long range nematic order is present but already finite-size
domains are formed which show orientational order. Domain formation
leads to a substantial slowing down of a collective
rotational mode
which separates well from the usual microscopic frequency regime. A
dynamic coupling of this particular mode into all other modes provides
a general mechanism which explains an excess peak in spectra of
molecular fluids. Using molecular dynamics simulation on up to 4096 particles
and on solving the molecular mode coupling equation we investigate
dynamic properties of the peak and prove its orientational origin.
64.70.Pf - Glass transitions.
61.30.-v - Liquid crystals.
61.25.Em - Molecular liquids.
61.20.Lc - Time-dependent properties; relaxation.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2002
