Dumbbell‐Like Fe3O4–Au Nanoparticles for Ultrabroadband Electromagnetic Losses by Heterogeneous Interfacial Polarizations

Dumbbell-like Fe3O4–Au superparamagnetic nanoparticles exhibit enhanced electromagnetic losses at gigahertz ascribed to the epitaxial Fe3O4/Au interfaces that induce anisotropic polarizations. This provides insight into the microscopic dielectric polarization of heterogeneous hybrids of noble metal and magnetic oxide and thus has implication for potential applications, such as the development of high electromagnetic loss materials.