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

P5.18Wed 711:10-14:00Structural and thermodynamical imprints of clusterformation in two-Yukawa fluidsJean-Marc Bomont, 1 Jean-Pierre Hansen, 2 and Dino Costa 31 Lab. de Physique des Milieux Denses, 1 Bd. Fraçois Arago, 57078, Metz,France2 Chemical Laboratory, Cambridge, United Kingdom3 Dipartimento di Fisica, Messina, ItalyWe studied the formation of clusters in model colloidal suspensions, using accurate thermodyamicallyself-consistent integral equation theories (IETs) of the liquid state, with the goal of focussingon conditions for which the vapor-liquid coexistence is supplanted by microphase separation.Notwithstanding the impressive number of results devoted to the structural study of inhomogeneousphases, the homogeneous to a cluster fluid process occuring in the fluid has never beenconsidered as a genuine phase transition. In the present work, we challenge such an assumption. Athorough investigation, carried out at constant packing fraction and decreasing temperature, acrossthe threshold whereupon the nature of the system changes from a homogeneous fluid to a clusterfluid, has revealed neat structural and thermodynamical signatures of the change occuring in thefluid. We show in particular that if some refined self-consistent theoretical approaches are able topredict such signatures, as MC simulations do, this is not longer the case for unconsistent IETs.18