Dynamics in binary cluster crystals

As a result of the application of coarse-graining procedures to describe complex fluids, the study of systems consisting of particles interacting through bounded, repulsive pair potentials has become of increasing interest in the last years. A well known example is the so-called Generalized Exponential Model (GEM-m), for which the interaction between particles is described by the potential v(r) = 2 exp[−(r/σ)m]. Interactions with m > 2 lead to the formation of a novel phase of soft matter consisting of cluster crystals. Recent studies on the phase behavior of binary mixtures of GEM-m particles have provided evidence for the formation of novel kinds of alloys, depending on the cross interactions between the two species. This work aims to study the dynamic behavior of such binary mixtures by means of extensive molecular dynamics simulations, and in particular to investigate the effect of the addition of non-clustering particles on the dynamic scenario of one-component cluster crystals. Analogies and differences with the one-component case are revealed and discussed by analyzing selfand collective dynamic correlators. PACS numbers: 61.20.Ja, 64.70.Pf, 82.70.-y