Synthesis and Characterization of Cobalt Ferrite (CoFe₂O₄) Magnetic Nanoparticles by Ball-Milling and Sol-Gel Techniques

Magnetic nanostructures play an important role in nanotechnology allowing for technological advances in electronic devices, photocatalysis, sustainable energy, biotechnology and medicine. In particular, cobalt ferrite (CoFe₂O₄) magnetic nanoparticles (MNP) have strong uniaxial magnetic moments, which allow for applications in hyperthermia and targeted drug delivery. Therefore, these particles were synthesized using two different techniques: mechanochemical ball-milling and sol-gel. Using Mössbauer Spectroscopy, X-Ray diffraction, Transmission Electron Microscopy, SQUID magnetometry, and Specific Absorption Rate (SAR) measurements, their magnetic, structural, and thermal transfer characteristics were analyzed and compared to maghemite (gamma-Fe₂O₃) and magnetite (Fe₃O₄) MNPs. In addition, for cobalt ferrite nanoparticles to be used within the body they must be rendered bio-compatible through surface ligand exchange processes in order to avoid being targeted by the body’s auto-defense system. Therefore, different ligands were experimented with to determine an optimal coating for usage in the body.