Synthesis and Characterization of Superparamagnetic Fe₃O₄@SiO₂ Core-Shell Composite Nanoparticles

Meizhen Gao, Wen Li, Jingwei Dong, Zhirong Zhang, Bingjun Yang

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DOI: 10.4236/wjcmp.2011.12008                

Abstract

The Fe₃O₄@SiO₂ composite nanoparticles were obtained from as-synthesized magnetite (Fe₃O₄) nanoparticles through the modified Stöber method. Then, the Fe3O4 nanoparticles and Fe₃O₄@SiO₂ composite nanoparticles were characterized by means of X-ray diffraction (XRD), Raman spectra, scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). Recently, the studies focus on how to improve the dispersion of composite particle and achieve good magnetic performance. Hence effects of the volume ratio of tetraethyl orthosilicate (TEOS) and magnetite colloid on the structural, morphological and magnetic properties of the composite nanoparticles were systematically investi-gated. The results revealed that the Fe3O4@SiO2 had better thermal stability and dispersion than the magnetite nanoparticles. Furthermore, the particle size and magnetic property of the Fe₃O₄@SiO₂ composite nanoparticles can be adjusted by changing the volume ratio of TEOS and magnetite colloid.

Keywords

Magnetite Nanoparticles, Fe₃O₄@SiO₂ Composite Nanoparticles, Dispersion, Thermal Stability, Particle Size, Magnetic Property

Conflicts of Interest

The authors declare no conflicts of interest.

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