Heterogeneous crystallization in colloids and complex plasmas: the role of binary mobilities

Abstract

Both charged colloidal suspensions and complex (dusty) plasmas represent classical many-body strongly coupled Coulomb systems. Here we discuss their basic properties and focus on their heterogeneous crystallization from an undercooled melt. In particular, a model with different mobilities is proposed which is realizable in binary mixtures of charged particles. Within this binary-mobility model, the crystallization behaviour near a structured wall is explored by Brownian dynamics computer simulations. As a result, the propagation velocity of the crystal-fluid interface is a nonmonotonic function of the mobility ratio (if expressed in terms of an averaged mobility).

Dynamics of two-dimensional one-component and binary Yukawa systems in a magnetic field

“…Moreover, it is known that the crystallization process out of an undercooled melt depends sensitively on the mobility ratio in binary systems [39] such that the magnetic field can be used to tune crystal nucleation in mixtures [40][41][42][43].…”

Dynamics of two-dimensional complex plasmas in a magnetic field

“…For future studies, as regards binary systems, a systematic understanding of the two-dimensional glass transition in binary mixtures is lying ahead where the magnetic field is exploited as a steering wheel to change the mobility ratio between the particle species. Moreover, it is known that the crystallization process out of an undercooled melt depends sensitively on the mobility ratio in binary systems [39] such that the magnetic field can be used to tune crystal nucleation in mixtures [40][41][42][43].…”

Microscopic approach to entropy production

“…Here, the letters 'eq' denote equilibrium quantities, •|• eq is Mori's scalar product [11] and Xeq ( r, t ) = X ( r, t ) − X eq ( r ) with X eq ( r ) = X ( r, t ) eq are the equilibrium fluctuations of the variable X ( r, t ). Since they are associated with equilibrium fluctuations, the time correlation functions (30) are translationally invariant with respect to time:…”

“…For colloidal crystallization there is no latent heat since the solvent thermalizes the system instantaneously. For crystallization in molecular systems [28] or complex plasmas [29], on the other hand, latent heat is produced which slows down further crystal growth [30]. Our approach includes the corresponding entropy production upon crystallization and therefore provides an ideal microscopic framework to describe crystallization processes even in dusty plasmas [29].…”