淀粉基碳包覆铁纳米胶囊的合成及其磁学性能

淀粉基碳包覆铁纳米胶囊的合成及其磁学性能

  • 摘要: 以淀粉为碳源,通过热解炭化铁/淀粉复合物,成功制备出碳包覆铁(Fe@C)纳米胶囊。在这一过程中淀粉有双重作用,既是碳源又是铁纳米颗粒的稳定剂。采用透射电镜、X射线衍射及振动样品磁强计研究了(Fe@C)纳米胶囊的结构和磁学性能。发现Fe@C纳米胶囊具有完美的铁核(bcc-Fe)/碳壳(石墨层片)包覆结构,其尺寸介于30nm~40nm之间;Fe@C纳米胶囊在室温下有低的剩磁比(Mr/Ms = 0.11),表明它在室温下具有超顺磁性。

     

    Abstract: Carbon encapsulated iron (Fe@C) nanocapsules were successfully prepared by pyrolyzing iron/starch composites under mild conditions, in which starch functioned as carbon precursor and stabilizer for iron nanoparticles. The asobtained Fe@C nanocapsules were examined by TEM, XRD and a vibrating sample magnetometer. Results show that the Fe@C nanocapsules with diameters in a narrow range of 3040nm feature wellconstructed core/shell structures, consisting of a bccFe core and a graphitic shell. The Fe@C nanocapsules have a low ratio of remanence to saturation magnetization (Mr/Ms = 0.11), implying that they are superparamagnetic at room temperature.

     

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