8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P8.58Thu 811:10-14:00Effect of size polydispersity on the Yukawa meltingtransitionMarjolein van der Linden, 1 Alfons van Blaaderen, 1 and Marjolein Dijkstra 11 Soft Condensed Matter, Debye Institute, Princetonplein 1, 3584 CC, Utrecht,NetherlandsWe investigate the effect of size polydispersity on the melting transition in hard-core repulsiveYukawa systems by means of Monte Carlo simulations for several state points in the Yukawaparameter space. Size polydispersity is introduced in the system under the experimentally relevantcondition of constant surface potential, allowing the charge on the particles to vary with particlesize. We observe a shift to higher packing fraction of the melting transition of bulk crystals witha fixed log-normal size distribution upon increasing the polydispersity, which is more pronouncedfor weakly charged particles (ψ ≈ 23 mV) compared to more highly charged particles (ψ ≈46 mV), and also for larger Debye screening length. At high polydispersities (> 10%) we observeimmediate partial melting, indicating the presence of a terminal polydispersity beyond which thehomogeneous crystal phase no longer exists.58