SiO2包覆羰基铁粉电磁特性及吸波性能研究

Study on Electromagnetic and Microwave Absorption Properties of Carbonyl Iron Powder Coated by SiO2

通过正硅酸乙酯(TEOS)水解,在羰基铁表面包覆SiO2,对其进行表面改性,研究表面包覆时间对电磁特性和吸波性能的影响。采用XRF、FT-IR对样品的元素及化学键进行表征,使用TEM分析样品表面形貌,确定包覆层厚度。利用矢量网络分析仪对样品的电磁参数进行测量,研究其吸波性能。结果表明:羰基铁表面包覆层厚度约为40~60nm,随包覆时间延长,包覆层厚度逐渐增加并致密;经模拟,包覆后同等厚度样品对电磁波的吸收峰向高频移动,频带宽度(RL≤-10dB)明显增加;包覆2h样品,反射损耗最小,最佳反射损耗值为-45.18dB,展现出了良好的吸波性能。

In order to study the effect of surface coating time on electromagnetic properties and microwave absorbing properties, carbonyl iron was coated with SiO2 by hydrolysis of tetraethyl orthosilicate(TEOS). The elements and chemical bonds of the samples were characterized by XRF and FT-IR, and the surface morphology of the samples was analyzed by TEM to determine the thickness of the coating. The electromagnetic parameters were measured by a vector network analyzer to study its absorbing properties. The results show that the surface coating thickness is about 40-60 nm. With the coating time prolonged, the thickness of the coating layer gradually increases. After simulation, the absorption peak of the electromagnetic wave after coating is moved to a high frequency, band width(RL≤ -10 dB) increases significantly. The sample coated for 2 h has the smallest reflection loss, the lowest peak value is-45.18 dB, which shows good absorbing performance.