Quantifying Magnetostatic States of Magnetite Nanoparticle Arrangements Via Electron Holography and Micromagnetic Simulations

Off-axis electron holography (OAEH) and micromagnetic simulations were employed to study the structural and magnetic properties of closely spaced Fe 3 O 4 nanoparticle (NP) arrangements that exhibit distinct sizes, shapes, crystallographic orientations, and spatial arrangements. OAEH results demonstrate that the individual Fe 3 O 4 NPs are single magnetic domain and the NPs arrangements exhibit characteristic magnetization distributions within the NPs and induction fields around the NPs. Micromagnetic simulations assess the interplay between the shape anisotropy and the magnetocrystalline anisotropy of NPs arrangements. Our findings of the magnetostatic states of NPs arrangements exemplify a model case for evaluating the intricate magnetic interactions of magnetic nanostructures.