Magnetic interactions between nanoparticles

Abstract

SummaryWe present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state of nanoparticles. This collective state has many similarities to spin-glasses. In samples of aggregated magnetic nanoparticles, exchange interactions are often important and this can also lead to a strong suppression of superparamagnetic relaxation. The temperature dependence of the order parameter in samples of strongly interacting hematite nanoparticles or goethite grains is well described by a simple mean field model. Exchange interactions between nanoparticles with different orientations of the easy axes can also result in a rotation of the sub-lattice magnetization directions.

Investigation of magnetite Fe3O4 nanoparticles for magnetic hyperthermia

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Synthesis and characterization of iron oxide magnetic nanoparticles

“…The last sextet that corresponds to the lowest magnetic fi eld exhibits strongly broadened lines. This can be associated with the surface disorder and magnetic interactions between the nanoparticles [19]. Although the diameter of the nanoparticles is equal to 14 nm, superparamagnetic relaxation is absent at RT.…”

The Néel Magnetic Relaxation Dynamics in Nanoparticle Systems - Phenomenological Approach versus Stochastic Approach

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