Controlling Topological Defects in Colloidal Crystal Shells of Hard Superballs

Just as a soccer ball cannot be made solely with hexagonal patches, spherical particles confined to the surface of a sphere cannot arrange densely into a hexagonal lattice without disclinations. In physical systems such as Pickering emulsions, in which droplets are stabilized by colloidal particles added to the droplet interface, these disclinations and defect scars decorate the surface with icosahedral symmetry. Here we use hard particle Monte Carlo simulations to determine the effect of particle shape and lattice preference in flat space on the structure and distribution of defects in spherical shells filled densely with colloidal particles whose shape varies continuously from a sphere to a cube. We describe defect scar analogues for these systems and show how the scar pattern relates to particle shape.