Investigation of surface passivation process on magnetic nanoparticles by Raman spectroscopy

A detailed study of the surface passivation process in superparamagnetic cobalt ferrite nanoparticles has been carried out using micro Raman spectroscopy. In addition to Raman spectroscopy, X-ray diffraction and atomic absorption spectroscopy were also used to investigate passivated and non-passivated samples. The data were discussed in terms of changes in the structural characteristics of the samples considering the introduction of Fe ions during the passivation. We found an improvement of the nanoparticle crystallinity due to the passivation process.