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

采用金属有机化学气相沉积(MOCVD)工艺在微米级Ni0.4Zn0.2Mn0.4Ce0.06Fe1.94O4(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1.8mm时,反射率最小值为–39.9dB,小于–10dB的吸波带宽为14.2GHz(3.818GHz)。涂层厚度为0.82.6 mm时,在3.218 GHz均能实现最小反射率低于–20 dB,在2.518 GHz均能实现最小反射率低于–10dB,仅需要调整厚度,即可以实现218 GHz内良好的吸波效果。

By analyzing the complementary relationship among ferrite and carbonyl iron power, a carbonyl iron coated core-shell nano composite absorbent system was 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 was obtained. The nano carbonyl iron(CI) shell in situ grown on Ni0.4Zn0.2Mn0.4Ce0.06Fe1.94O4(NZMCF) surface by metal organic chemical vapor deposition(MOCVD) was used as electromagnetic wave(EMW) absorbing materials. X-ray diffraction, scanning electron microscope and energy dispersive spectrometer analyses show that NZMCF-CI composites were successfully prepared with a core-shell structure. Optimizing the mass ratio of CI would likely cause the composites to attain the EM parameters necessary in EMW absorbing materials. A minimum reflection loss(RL) is –39.9 dB when the corresponding thickness is 1.8 mm, and the RL exceeds –10 dB from 3.8 to 18.0 GHz. The minimum RL exceeds –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.