Magnetotunable Hybrid Films of Stratified Iron Oxide Nanoparticles Assembled by the Layer-by-Layer Technique

Multilayer assemblies of iron oxide nanoparticles with tunable magnetic properties have been prepared by the layer-by-layer technique. The magnetic properties of multilayer assemblies depend closely on the stacking of nonagglomerated nanoparticles and, in particular, on the interlayer distance between nanoparticles, which is defined by the thickness of the polyelectrolyte multilayers. Therefore, the dipolar interactions between nanoparticles were demonstrated to occur preferentially in the plane of the nanoparticle layers and to result in the antiparallel magnetic coupling of adjacent nanoparticle layers, which is modulated as a function of the interlayer distance.