The influence of polydispersity on the structural properties of the isotropic phase of magnetic nanoplatelets

Abstract

By employing a combination of Molecular Dynamics simulations and experimental SAXS studies, we investigate low-concentration suspensions of polydisperse magnetic platelets with dipole moments perpendicular to the platelets' plane. Exploiting the precise control of platelet size and shape in simulation, we are also able to contrast these results with equivalent density monodisperse suspensions. We show how the polydispersity may lead to the reduction of the orientational and spatial correlations in the absence of an applied field, while simultaneously facilitating the field-induced transition into a nematic-like phase. Along with structural properties, we investigate the magnetic response. This allows us to confirm that the inter-platelet magnetic correlations have a negligible influence on the structure of the low-density suspensions.