科研之友
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摘要
Fe3O4 nanocrystallines were successfully prepared by using the mixed surfactants of SDS and PEG as the protective reagents. The sizes of the nanoparticles can be varied from 10 to 200 nm by adjusting the experimental conditions. The microstructure, size and morphology of the products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results indicate that uniform spinel Fe3O4 nanospheres were achieved. Magnetic studies on the samples with different sizes reveal that when the size of product is below 80 nm, the saturation magnetization (M-s) increases as the particle size increases, where the coercive force (H-c) decreases as the particle size decreases. Both of electromagnetic performance and microwave adsorption property. of Fe3O4 nanocrystallines with different sizes were measured by a vector network analyzer(VNA) technique in the frequency region of 2-18 GHz. The results indicate that when the sizes of the samples are below 100 nm, Fe3O4 nanocrystallines exhibit a better microwave adsorption property. For example, the reflection loss is up to 32 dB for the sample with the nanopartiele size of 20 nm.
- 出版日期2008-1-10
- 单位中南大学
