Dynamics of uniaxial hard ellipsoids.
We study the dynamics of monodisperse hard ellipsoids via a new event-driven molecular dynamics algorithm as a function of volume fraction phi and aspect ratio X0. We evaluate the translational D(trans) and the rotational D(rot) diffusion coefficients and the associated isodiffusivity lines in the phi-X0 plane. We observe a decoupling of the translational and rotational dynamics which generates an almost perpendicular crossing of the D(trans) and D(rot) isodiffusivity lines. While the self-intermediate scattering function exhibits stretched relaxation, i.e., glassy dynamics, only for large phi and X(0) approximately 1, the second order orientational correlator C2(t) shows stretching only for large and small X0 values. We discuss these findings in the context of a possible prenematic order driven glass transition.
De Michele
Cristiano
C
Dipartimento di Fisica and INFM-CRS Soft, Università di Roma La Sapienza, Piazzale A. Moro 2, 00185 Roma, Italy.
Schilling
Rolf
R
Sciortino
Francesco
F