Optimizing Cobalt Ferrite Nanocrystal Synthesis Using a Magneto-optical Probe

A modified approach toward synthesizing colloidal CoFe 2 O 4 nanocrystals, using mixed types of organometallic precursors, is presented and compared to CoFe 2 O 4 nanocrystals that have been produced according to previously reported synthetic techniques. Although the standard characterization techniques, such as electron microscopy, energy-dispersive X-ray spectroscopy, magnetometry, Fourier transform infrared spectroscopy, and X-ray diffraction, provided similar results for nanocrystals from three different syntheses, magneto-optical (MO) spectroscopy is the only technique that has revealed significant differences between these preparation techniques. The MO spectra displayed substantial differences in the incorporation of Co 2+ ions within the ferrite crystal structure, making it a unique probe for optimizing the synthesis of stoichiometrically and structurally precise cobalt-ferrite nanoparticles.