Dependence of the composition, morphology and magnetic properties with the water and air exposure during the Fe1-yO/Fe3O4 core–shell nanoparticles synthesis

LOHR, J.; VASQUEZ MANSILLA, M.; GERBALDO, M. V.; MORENO, M. S.; TOBIA, D.; GOYA, G. F.; WINKLER, E. L.; ZYSLER, R. D.; LIMA, E.

JOURNAL OF NANOPARTICLE RESEARCH

SPRINGER

Lugar: Berlin; Año: 2021 vol. 23 p. 140 - 140

1388-0764

The thermal decomposition of organometallic precursorsin the presence of surfactants and a long-chain alcohol is a valuable method tosynthesize magnetic nanoparticles (MNPs) because it provides good control ofthe final morphology and crystallinity of the magnetic material. Theseparameters, and consequently the magnetic properties, depend on several details of theexperimental procedure of chemicalsynthesis. We have studied the role of thepredecomposition step, heating the system to 373?393 K in inert gas flux, onthe final composition and morphology of the system. By adding this intermediatestep, we were able to produce MNPs with a Fe1-yO/Fe3O4 core?shell structure andsizes of 20?25 nm. When the same synthesis protocol was used skipping thepre-decomposition stage, monophasic MNPs of 11 nm with ferrite structure wereobtained. These differences in the composition have a major effect on theresulting magnetic properties of MNPs, and are related to some by-reactions inthe synthesis solution during the preparation procedure.