Eur. Phys. J. B 42, 391-396 (2004)
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

Abstract

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.