https://doi.org/10.1140/epjb/e2004-00395-2
Decoupling-coupling of rotations as a mechanism of glass transition
Departamento de Física Aplicada, Universidad Politécnica de Cartagena,
Campus Muralla del Mar, Cartagena, 30202 Murcia, Spain
Corresponding author: a andiaz@upct.es
Received:
13
January
2004
Revised:
20
October
2004
Published online:
23
December
2004
We introduce a three-dimensional lattice gas model to study the glass
transition. In this model the interactions come from the excluded volume
and particles have five arms with an asymmetrical shape,
which results in geometric frustration that inhibits full packing.
Each particle has two degrees of freedom, the position and the orientation
of the particle. We find a second order phase transition at a density
,
this transition decouples the orientation of the particles which can rotate
without interaction in this degree of freedom until
is
reached. Both the inverse diffusivity and the relaxation time follow a power
law behavior for densities
. The crystallization at
is avoided because frustration lets to the system to reach higher
densities, then the divergencies are overcome.
For
the orientations of the particles are coupled and
the dynamics is governed by both degrees of freedom.
PACS: 64.70.Pf – Glass transitions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004