In silico study of area fraction effects on the behaviour of a ferrogranulate layer in an orthogonal applied field

In our study, we explore ferrogranulate—a mix of glass and steel particles, specifically Stockmayer and repulsive spheres. Confined to a monolayer with three-dimensional rotation, magnetic particles respond to an external magnetic field applied orthogonal to the granulate plane. By varying the overall area fraction while maintaining a constant steel-to-glass bead ratio, we analyse cluster formation. Results show that concentration growth both slows cluster dynamics and increases the likelihood of larger clusters, hindering the response to the magnetic field. At low applied field values, our calculations suggest a bistable region at high concentrations, where droplet precursors form due to dipolar and steric interactions.