Small CoFe2O4 magnetic nanoparticles in ferrofluids, influence of the synthesis on the magnetic anisotropies

The magnetic properties of cobalt ferrites nanoparticles prepared using three different processes (thermal decomposition, polyol and co-precipitation synthesis routes) are investigated by X-ray Absorption Spectroscopy and X-ray Magnetic Circular Dichroism. The repartition of cobalt and iron ions amongst the interstitial sites of the spinel structure is determined and correlated with their magnetic properties. The study reports on the influence of the synthesis method on the crystallographic order within a nanoparticle, and hence, on the magnetic anisotropy.