Arrested phase separation in a short-ranged attractive colloidal system: a numerical study.
We numerically investigate the competition between phase separation and dynamical arrest in a colloidal system interacting via a short-ranged attractive potential. Equilibrium fluid configurations are quenched at two different temperatures below the critical temperature and followed during their time evolution. At the lowest studied T, the phase-separation process is interrupted by the formation of an attractive glass in the dense phase. At the higher T, no arrest is observed and the phase-separation process proceeds endlessly in the simulated time window. The final structure of the glass retains memory of the interrupted phase-separation process in the form of a frozen spinodal decomposition peak, whose location and amplitude is controlled by the average packing fraction. We also discuss the time evolution of the nonergodicity parameter, providing evidence of a progressively decreasing localization length on increasing the packing fraction. Finally, we confirm that the reported results are independent of the microscopic dynamics.
Institut Romand de Recherche Numérique en Physique des Matériaux, PPH-Ecublens, CH-105 Lausanne, Switzerland. giuseppe.foffi@epfl.ch
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