2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/28596We consider the nature of the fluid-solid phase transition in a polydisperse mixture of hard spheres. For a sufficiently polydisperse mixture crystallisation occurs with simultaneous fractionation. At the fluid-solid boundary, a broad fluid diameter distribution is split into a number of narrower fractions, each of which then crystallises. The number of crystalline phases increases with the overall level of polydispersity. At high densities, freezing is followed by a sequence of demixing transitions in the polydisperse crystal.10 pages, 4 figures to appear in J. Chem. PhysCondensed Mattertext