Influence of silica coating process on fine structure and magnetic properties of iron oxide nanoparticles

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• 作者：Liu Jia ^{liu.j.af@m.titech.ac.jp" class="auth_mail" title="E-mail the corresponding author} ; Yoshitaka Kitamoto ; ^{kitamoto.y.aa@m.titech.ac.jp" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Superparamegnetic iron-oxide (SPIO) ; Core-shell ; Nanoparticle ; Magnetic property
• 刊名：Electrochimica Acta
• 出版年：2015
• 出版时间：20 November 2015
• 年：2015
• 卷：183
• 期：Complete
• 页码：148-152
• 全文大小：2344 K

文摘

We present influences of silica coating process on the nanostructure and magnetic properties of superparamagnetic iron-oxide (SPIO) nanoparticles (NPs). The silica coating on SPIO NPs is done to render the composite particles suitable for biomedical applications. SPIO NPs synthesized using iron oleate in the present study are composed of an antiferromagnetic FeO core and a ferromagnetic Fe₃O₄ shell except NPs of 7 nm in diameter, which are a single crystal of Fe₃O₄. The conversion of FeO phase to Fe₃O₄ phase at their interface resulting from silica coating is confirmed using X-ray diffraction and magnetic measurements. The magnetic properties of SPIO NPs change with the increase in volume fraction of Fe₃O₄ due to the conversion from FeO by the silica coating. In addition, a temperature-dependent magnetization reveals that the magnetic interaction between the antiferromagnetic FeO and the ferromagnetic Fe₃O₄ influences the magnetic properties. These results suggest the strategy to obtain optimum magnetic properties of iron oxide/silica composite particles for biomedical applications.