采用NaBH4溶液还原FeCI3的方法制备Fe-B颗粒,并在Ar/O2气氛下干燥,使其表面不完全氧化,得到了Fe-B/Fe3O4纳米复合粒子.该粒子具有清晰的核壳结构,内核Fe-B尺寸约为20～50 nm,外壳Fe3O4厚度约为3 nm.将样品与石蜡按质量比1:1制成同轴样品,测试其2～18 GHz下的电磁参数并进行分析计算,研究发现,由于偶极子极化、自然共振和涡流损耗,该纳米复合粒子粉末具有优良的吸波性能,其反射损耗RL在频率为12.0GHz的时候达到最小值-31 dB,RL值低于-20 dB(即吸收率高于99%)的频率范围为10.1～14.2 GHz.
Fe-B/Fe3O4 nanoparticles were prepared by chemical reduction with borohydride and dried in Ar/O2 at-mosphere. The nanoparticles have clear core/shell structure with the Fe-B core of 20-50 nm and the Fe3O4 shell of 3 nm. The nanoparticles were mixed with paraffin (1:1 in mass ratio) to form a ring sample for measuring the complex electromagnetic parameters in the frequency range of 2-18 GHz. Jt is found that the composite exhibits ex-cellent microwave absorption properties (reflection loss<-20 dB) in the range 10.1-14.2 GHz due to the orient-ational polarization, natural resonance and eddy current loss.
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