Structural origin of dynamic heterogeneity in three-dimensional colloidal glass formers and its link to crystal nucleation

J Phys Condens Matter. 2010 Jun 16;22(23):232102. doi: 10.1088/0953-8984/22/23/232102. Epub 2010 May 21.

Abstract

The physical understanding of glass transition remains a major challenge of physics and materials science. Among various glass-forming liquids, a colloidal liquid interacting with hard-core repulsion is now regarded as one of the most ideal model systems. Here we study the structure and dynamics of three-dimensional polydisperse colloidal liquids by Brownian dynamics simulations. We reveal that medium-range crystalline bond orientational order of the hexagonal close packed structure grows in size and lifetime with increasing packing fraction. We show that dynamic heterogeneity may be a direct consequence of this transient structural ordering, which suggests its origin is thermodynamic rather than kinetic. We also reveal that nucleation of crystals preferentially occurs in regions of high medium-range order, reflecting the low crystal-liquid interfacial energy there. These findings may shed new light not only on the fundamental nature of the glass transition, but also the mechanism of crystal nucleation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Colloids / chemistry*
  • Crystallization
  • Glass / chemistry*
  • Kinetics
  • Models, Molecular
  • Molecular Conformation
  • Physics / methods
  • Thermodynamics

Substances

  • Colloids