氧化锌晶须电磁波吸收性能研究

Study on the microwave absorption of Zinc oxide whiskers

用四针状氧化锌晶须作为电磁波吸收材料．研究了氧化锌晶须结构对算电磁波吸收性能的影响：用SEM表征了其形貌．分析了氧化锌晶须针状体长径比、截面形貌和晶体结构等结构因素对其在8～12GHz电磁波频段吸收性能的影响，并初步分析了结构导致其电磁波吸收性能差异的原因。

In this paper,the microwave absorption behaviors of zinc oxide whiskers were studied. The morphological structure of zinc oxide whiskers was observed through scanning electron microscope. The effect of the structure of zinc oxide whiskers on the microwave absorption, such as length-diameter ratio, cross-section appearance and doping et al, was discussed. It shows that the more irregular the cross section of the needle of zinc oxide whiskers is, the more prominent the microwave absorption appears. The less the length-dlameter ratio of the needle of zinc oxide whiskers is,the more obvious the microwave absorption of zinc oxide whiskers is. The zinc oxide whiskers which had inlet ion, such as Al^3＋ , Fe^3＋ etal, in its crystal lattice have a better microwave absorption efficiency than the pure zinc oxide whiskers. The further analysis found that electric conductive network can be formed easily because of the zinc oxide whiskers and the coating had the honeycomb structure. When microwave reach the coating of zinc oxide whiskers,the polarization of zinc oxide whiskers was resulted and the electromagnetic energy lost. Firstly, electric current was transmitted through the electric conductive network and the energy transformed to heat. Secondly,tips＇ discharge phenomenon has been observed,which lead to the energy lost. Finally,the microwave energy lost because of the tunnel effect, which will bring about leakage current. Based on the above three reasons, microwave energy was absorbed by the coating containing zinc oxide whiskers.