SiO_2包覆片状羰基铁粉的制备及电磁性能

采用机械球磨法使羰基铁粉片状化,以正硅酸乙脂(TEOS)为硅源,通过St?ber法制备二氧化硅(Si O_2)包覆的片状羰基铁粉。通过扫描电子显微镜、能谱、红外光谱、X射线衍射等手段研究了Si O_2包覆的羰基铁粉的结构特性,并讨论了Si O_2包覆对其热性能、电磁和微波吸收性能的影响。结果表明,Si O_2包覆羰基铁粉的抗氧化性能显著提高。与未包覆羰基铁相比,包覆后羰基铁粉的介电常数急剧下降,在1~6GHz波段内具有较好的吸波效果。当厚度为3.4 mm时,在2 GHz处的最小反射损耗可以达到-25.6 d B。

Preparation and electromagnetic properties of SiO2 coated carbonyl iron particles with flake-shape

Carbonyl iron flakes were prepared by ball-milling technique, and then were coated with SiO2 by St?ber method.The structure characterization of the SiO2 coated carbonyl iron flakes were investigated by means of SEM, EDS, FT-IR and XRD. The influence of SiO2 coating on thermal, electromagnetic and microwave absorbing properties of carbonyl iron flakes were discussed. The results show that the oxidation resistance was enhanced for flake-shaped carbonyl iron particles with SiO2 coating. The permittivity of carbonyl iron particles decrease dramatically after coating with SiO2, and a good microwave absorption was obtained in 1-6GHz. For the sample with absorber thickness of 3.4mm, a minimum reflection loss of-25.6dB can be achieved in 2GHz.