The magnetic and oxidation behavior of bare and silica-coated iron oxide nanoparticles synthesized by reverse co-precipitation of ferrous ion (Fe.sup.2+./sup.) in ambient atmosphere

0422566 - FZÚ 2015 RIV NL eng J - Journal Article
Mahmed, N. - Heczko, Oleg - Lančok, Adriana - Hannula, S.-P.
The magnetic and oxidation behavior of bare and silica-coated iron oxide nanoparticles synthesized by reverse co-precipitation of ferrous ion (Fe²⁺) in ambient atmosphere.
Journal of Magnetism and Magnetic Materials. Roč. 353, MAR (2014), s. 15-22. ISSN 0304-8853. E-ISSN 1873-4766
R&D Projects: GA ČR(CZ) GAP107/11/0391
Institutional support: RVO:68378271
Keywords : reverseco-precipitation * ferrousion * magnetite * Mössbauer * silica
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.970, year: 2014
http://www.sciencedirect.com/science/article/pii/S0304885313007336

The synthesis of iron oxide nanoparticles, i.e., magnetite was attempted by using only ferrous ion (Fe2+) as a magnetite precursor, under an ambient atmosphere. The room temperature reverse co-precipitation method was used, by applying two synthesis protocols. The freshly prepared iron oxide was also immediately coated with Stöber silica (SiO2) layer, forming the coreshell structure. The phase, stoichiometry, crystallite and the particle size of the synthesized powders were determined by using X-ray diffraction (XRD) and transmission electron microscope (TEM), while the magnetic and oxidation behaviors were studied by using the vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. Based on the results, the bare iron oxide nanoparticles are in the stoichiometry between the magnetite and the maghemite stoichiometry, i.e., oxidation occurs. This oxidation is depending on the synthesis protocols used.
Permanent Link: http://hdl.handle.net/11104/0228707