FeCoNi合金超细粉体的制备及其微波性能研究

Fabrication and Absorption of FeCoNi Alloy Fine Powders

采用硝酸盐柠檬酸溶胶凝胶法结合氢还原法制备FeCoNi合金超细粉体。用扫描电镜观察粉体的形貌,用激光粒度分析仪测试粉体的粒度,结果显示：合金粉体呈现片状和针状,粒度分布很宽。将制备的合金粉与石蜡按质量比80∶20混合制成样品,在0.5～8 GHz内,采用矢量网络分析仪测试样品的电磁参数。研究结果显示：合金粉体μ′≥2的频率至少高于3 GHz,有的达到6 GHz;样品的磁导率虚部曲线呈现多模共振的形式。材料反射率计算显示,合金粉的5 dB吸波频宽可达5.91 GHz（2.09～8 GHz）。

Fine powders of FeCoNi with different nominal Co,Ni content were prepared by citric nitrate sol-gel method and thermal treatment in hydrogen atmosphere.The morphology and particle sizes of samples were characterized by SEM and laser particle size analyzer.The results show that FeCoNi powders have a needle-like（or flake-like）shape with a wide particle size disturbution.And the obtained powders were randomly dispersed in paraffin at a mass ratio of 80∶20 for microwave electromagnetic parameters test in the frequency range of 0.5~8 GHz.The frequencies of samples whose μ′≥2 are at least 3 GHz,for certain samples even as high as 6 GHz.The imaginary parts of complex permeability of the samples exhibit several slightly damped ferromagnetic resonances.The calculation reflection losses of paraffin composites with alloy powders achieve a microwave Absorption of 5 dB with a band width of 5.91 GHz（2.09～8 GHz）.