Study of phase transformations, structural, corrosion properties and cytotoxicity of magnetite-based nanoparticles

This paper presents the results of the structural, corrosion, magnetic properties and cytotoxicity of magnetite nanoparticles, phase transformations was studied by thermal annealing. It was established that thermal annealing of Fe3O4 nanoparticles led to three stages of phase transformations from magnetite to maghemite, with the subsequent formation of the hematite structure. Increasing annealing temperature lead to a change in the magnitudes of the hyperfine magnetic field, quadrupole displacement and isomeric shift that indicates a change in the crystal structure and annealing of defects, which eventually leads to the ordering of magnetic nanoparticles. Studying the degradation of nanoparticles in PBS solution shows us that a change in the crystal structure as a result of a decrease in the degree of perfection and the formation of amorphous inclusions leads to magnetic disordering and a subsequent change in the magnitude of the hyperfine magnetic field. Cytotoxicity results indicate that nanoparticles do not show cytotoxic activity against tested L929, PC-3 and HeLa cell lines, because in all experimental series metabolic activity of studies cells was not below 70% of control.