Ni0.4Zn0.2Mn0.4Ce0.06Fe1.94O4表面原位构筑纳米羰基铁的可控制备及吸波性能研究

Fabrication and microwave absorbing properties of Nano-carbonyl iron in situ grown on Ni0.4Zn0.2Mn0.4Ce0.06Fe1.94O4 surface

摘要:

采用MOCVD工艺在微米级Ni_0.4Zn_0.2Mn_0.4Ce_0.06Fe_1.94O₄(NZMCF)表面原位生长了纳米级羰基铁(CI)壳层,通过控制沉积温度,调控核壳形貌和吸波性能,得到了具有核壳结构的NZMCF -CI复合吸波剂,利用XRD、SEM、EDS及VNA等分析手段,重点研究了沉积温度对NZMCF -CI核壳粉体微观形貌、晶体结构、电磁参数及吸波性能的影响。结果表明：通过调节沉积温度,可以有效调控核壳粉体的形貌,进而调控吸波性能。沉积温度为220 ℃,NZMCF-CI核壳粉体具有最佳的形貌及吸波性能。利用测得的同轴环样品的电磁参数,计算出NZMCF -CI涂层在厚度为1.8 mm时,反射率最小值为-39.9 dB,小于-10 dB的吸波带宽为14.2 GHz(3.8~18 GHz)。涂层厚度为0.8~2.6mm时,在3.2~ 18 GHz均能实现最小反射率低于-20 dB,在2.5~18 GHz均能实现最小反射率低于-10 dB。仅需要调整厚度,即可以实现2~18 GHz内良好的吸波效果。

Abstract:

Ferrite and carbonyl iron power are the major absorbing components of conventional radar absorbing materials (RAM). However, conventional RAM made of the aforementioned single-absorbing components cannot meet the comprehensive requirements of “thin, wide, light, and strong.” By analyzing the complementary relationship among ferrite and carbonyl iron power, a carbonyl iron coated core-shell nano composite absorbent system is established. In addition, by changing the deposition temperature to adjust the morphologies and absorbing properties of powders, excellent performance of the new core-shell structure absorbent is obtained. The nano carbonyl iron (CI) shell in situ grown on Ni_0.4Zn_0.2Mn_0.4Ce_0.06Fe_1.94O₄ (NZMCF) surface by metal organic chemical vapor deposition (MOCVD) for using as electromagnetic wave (EMW) absorbing materials. X-ray diffraction, scanning electron microscope and energy dispersive spectrometer analyses show that NZMCF-CI composites successfully prepared with a core-shell structure. Optimizing the weight ratio of CI would likely cause the composites to attain the EM parameters necessary in EMW absorbing materials, a minimum reflection loss (RL) was -39.9 dB to the corresponding thickness was 1.8mm, and the RL exceeds -10 dB from 3.8 to 18.0 GHz. The RL exceeds -20 dB from 3.2 to 18 GHz and -10 dB from 2.5 to 18 GHz for the absorber thickness from 0.8 to 2.6 mm, which covers almost the whole 2 to 18.0 GHz.