Crystallisation and the glass transition in suspensions of hard colloidal spheres

Abstract

Recent experiments on suspensions of particles with steeply repulsive interactions are reviewed. These suspensions show the equilibrium freezing-melting transition and a glass transition similar to those obtained in computer simulations of the hard sphere system. The glass transition is identified, firstly, by the cessation of homogeneously nucleated crystallisation and, secondly, by failure of concentration fluctuations in the metastable colloidal fluid to decay on the experimental time scale. Intermediate scattering functions, measured by dynamic light scattering, clearly show the emergence of two slow relaxation processes as the glass transition concentration is approached from below. At the glass transition concentration the slower process is arrested. These slow relaxation processes, which span time windows of five decades, can be quantitatively described by the idealised version of mode coupling theory.