BaZn_2Fe_(16)O_(27)/石墨复合吸收剂的制备及其电磁吸波性能

Preparation of BaZn_2 Fe_(16)O_(27) ferrite /graphite composite absorbent and its electromagnetic absorbing performance

采用固相法制备W型铁氧体BaZn2Fe16O27，将其与石墨按不同配比机械混合，制备出电磁性能优异的复合吸收剂。通过x线衍射仪（XRD）、扫描电子显微镜（SEM）对固相法制得的铁氧体粉末进行晶体结构和微现形貌的分析，结果表明，实验制得的粉体为纯相的BaZn2Fe16O27-W型铁氧体，微观形貌为六角片状。同时，使用网络分析仪在2。12GHz的频率范围内对复合粉体微波电磁特性进行测试分析，并使用软件YRCompute模拟计算复合粉体的反射损耗，结果表明：铁氧体的磁损耗与石墨的介电损耗发生协同作用，复合粉体的电磁性能得到很大提高；随着石墨含量的增加，复合粉体的介电常数与介电损耗明显增加，介电损耗最大值从0．02升高到0，2，而磁导率与磁损耗则是先增大后减小；当石墨质量分数为4％时，复合粉体的反射损耗在5GHz左右达到最大值-40．6dB，并且小于一10dB的带宽达到4GHz，吸波性能优异。

Abstract：W-type ferrite BaZn2Fe16O27 prepared by the solid-state method was mechanically mixed with different content graphites to obtain compounded absorbent. The samples by a solid-state method were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results showed that the main phase of the powders was magnetoplumbite ferrite with a hexagonal shape. The microwave absorptive performance of the composite powders was studied from 2 to 12 GHz, and the reflection loss was simulated by the YRcompute software. The coordinate function of magnetic loss type ferrite and dielectric loss type graphite obviously improved the magnetic loss and dielectric loss of the composite powder, and optimized its absorbing properties. With the increase of the graphite content, the dielectric constant and the dielectric loss were increased. The maximum of the dielectric loss increased from 0. 02 to 0. 2, but the magnetic permeability and the magnetic loss firstly increased, then decreased. When the weight percentage content of graphite was 4% , the maximum reflection loss （RL） of the composite absorbent was about-40. 6 dB at 5 GHz. Moreover, the absorption bandwidth reached 4 GHz when RL was less than - 10 dB at Ku-band.