Simultaneous agglomeration of Fe/Au nanoparticles with controllability of magnetic dipole interaction

Assemblies of α-Fe/Au nanoparticles (NPs) with various volume fractions of α-Fe NPs were prepared by simultaneous agglomeration of α-Fe NPs and Au NPs in solution. Only the dipole interaction was affected by the magnetic interaction between α-Fe NPs in this system. The magnetic properties were significantly changed according to the volume fraction of the α-Fe NPs, with a high α-Fe NP volume fraction assembly exhibiting good soft magnetic properties.

► Assemblies of α-Fe/Au nanoparticles (NPs) to control the magnetic dipole interaction.
► Simultaneous agglomeration enabled precise volume fraction control of α-Fe NPs.
► Magnetic properties drastically changed depending on volume fraction of the α-Fe NPs.
► Magnetic dipole interaction dominated collective magnetic properties.
► Strong magnetic dipole interaction induced a soft magnetic property.