镀膜法制备高磁导率低介电片状吸收剂

Microwave absorbents with high permeability and low permittivity fabricated by vacuum deposition

提出一种基于磁控溅射镀膜技术制备高性能磁性吸收剂的方法,通过预涂一层可溶性有机薄膜在基底上,继而溅射一层磁性薄膜及SiO2介质层,后在溶剂中超声获得具有大宽厚比的片形吸收剂。该吸收剂由于其高达80的宽厚比而具备大的磁导率;而磁性薄膜之上覆盖一层SiO2介质层则显著降低了介电,提高了阻抗匹配性。在吸收剂体积分数仅10%、厚度1.6 mm时,反射率(RL)<-5 dB及<-10 dB的带宽分别达到了7.8 GHz(4.2~12 GHz)和7 GHz(10~17 GHz)。这说明该工艺可以用于制备高性能片形吸收剂,并在轻质高效吸波材料方面有很大应用潜力。

In this paper,a method for preparing high-performance magnetic absorbers based on magnetron sputtering coating technology was presented.A layer of soluble organic polymer thin film was pre-coated on the substrate,and then a magnetic thin film following an ultra-thin SiO2 coating was sputtered and ultrasonically crushed in a solvent to obtain a flaky absorbents.The flaky absorbents had a high magnetic permeability due to its large aspect ratio of about 80,and the insulative SiO2 layer on the magnetic film significantly reduced the permittivity and improved the impedance match.When the absorbent volume fraction was only 10%and the thickness was 1.6 mm,the bandwidths of reflection loss(RL)<-5 dB and<-10 dB reached 7.8 GHz(4.2 GHz^12 GHz)and 7 GHz(10 GHz^17 GHz)to achieve wide-band electromagnetic wave absorption.This shows that the proposed process could be used to prepare high magnetic permeability flaky absorbents and had great potential in preparation of lightweight and efficient microwave absorbers.