TY - JOUR
T1 - Surface oxidation, size and shape of nano-sized magnetite obtained by co-precipitation
AU - Nedkov, I.
AU - Merodiiska, T.
AU - Slavov, L.
AU - Vandenberghe, R. E.
AU - Kusano, Y.
AU - Takada, J.
N1 - Funding Information:
The work was supported in part by Bulgarian National Council for Scientific Research under contract TH-1/01 and by FWO – Flanders, Belgium.
PY - 2006/5
Y1 - 2006/5
N2 - The aim of the work was to investigate the influence of the co-precipitation processes on the magnetic properties, the shape and the surface oxidation of nano-sized magnetite particles. The literature data on the process chemistry are inconsistent. Our task was to clarify the impact of the oxidation on the particles' characteristics when two of the most widely quoted soft-chemistry approaches for preparation of such particles are applied. To this end, we investigated the influence of the Fe2+ oxidizing agent ratio and the Oswalt ripening on the magnetite particle shape and size. The process of oxidation takes place to a depth of approximately 3 nm, following the formula (Fe3+)A[Fe5x3+Fe2-6x2.5+ □x] BO4 with x up to 0.33. SQUID and Moessbauer measurements were carried out to characterize selected samples. The strongly defective surface of the spherical particle can be considered as being a superstructure, or a second magnetic phase, since it affects the particle's magnetic properties.
AB - The aim of the work was to investigate the influence of the co-precipitation processes on the magnetic properties, the shape and the surface oxidation of nano-sized magnetite particles. The literature data on the process chemistry are inconsistent. Our task was to clarify the impact of the oxidation on the particles' characteristics when two of the most widely quoted soft-chemistry approaches for preparation of such particles are applied. To this end, we investigated the influence of the Fe2+ oxidizing agent ratio and the Oswalt ripening on the magnetite particle shape and size. The process of oxidation takes place to a depth of approximately 3 nm, following the formula (Fe3+)A[Fe5x3+Fe2-6x2.5+ □x] BO4 with x up to 0.33. SQUID and Moessbauer measurements were carried out to characterize selected samples. The strongly defective surface of the spherical particle can be considered as being a superstructure, or a second magnetic phase, since it affects the particle's magnetic properties.
KW - Magnetic nanoparticles
KW - Magnetite
KW - Shape control
KW - Surface oxidation
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U2 - 10.1016/j.jmmm.2005.05.020
DO - 10.1016/j.jmmm.2005.05.020
M3 - Article
AN - SCOPUS:33644863540
SN - 0304-8853
VL - 300
SP - 358
EP - 367
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
IS - 2
ER -