碳包覆坡莫合金纳米颗粒的爆轰法制备及吸波性能研究

Formation mechanism and Electromagnetic Microwave Absorbing Properties of Carbon-encapsulated Permalloy Nanoparticles Prepared through Detonation

摘要:

采用尿素络合硝酸铁、硝酸镍制成的掺杂铁镍离子的安全性复合炸药,爆轰合成了碳包覆纳米坡莫合金复合粒子。通过TEM、XRD、Raman光谱对纳米粒子进行了形貌、结构和成分分析表明,所合成纳米粒子呈球形核壳结构,粒径为40～60nm,中心为铁镍合金核,外包覆层为石墨层与无定形碳。为检验所合成的碳包覆坡莫合金粒子的电磁波吸收性能,将之与石蜡制成复合涂层,通过矢量网格分析仪,在2-18GHz吸收频段对不同厚度复合涂层进行了电磁损耗能力测定。结果表明,当涂层厚度为2 mm时,铁镍原子比1:4纳米粒子的吸波层出现了双吸收峰,峰值分别为-14.6dB(9.7GHz)和-7.7dB(14.3GHz),-10dB吸收频带范围为8.5～11.8GHz；而铁镍原子比1:1纳米粒子的吸波层吸收波峰在12.88 GHz,峰值为-30dB,-10dB的吸收频带范围为9.7～14.4GHz,具有较宽吸收频带和优良的吸波性能。

Abstract:

Carbon-encapsulated Fe–Ni alloy nanoparticles were synthesized through detonation using safety composite explosive precursors doped with Fe (NO3)3? 9H2O and Ni(NO3)2?6H2O. The morphology, components, and structure of the synthesized carbon-encapsulated alloy nanoparticles were characterized through X-ray diffraction studies, Raman spectroscopy and Transmission electron microscopy attached with energy dispersive X-ray spectroscopy (EDS). Results showed that the carbon-encapsulated Fe–Ni nanoparticles with a core–shell structure. The grains exhibited sizes ranging from 40 nm to 60 nm and were uniformly distributed. The encapsulated metal core was mainly composed of different proportions of Fe and Ni. The outer shell was composed of graphite and amorphous carbon, also there were onion carbon formed by the graphitization of diamond clusters in the vicinity of the nanoparticles. The electromagnetic characteristics of Fe–Ni alloy nanoparticles composites were measured by Agilent microwave network analyzer in the band of 2～ 18 GHz. The experimental results show that, 2 mm in thickness reflection loss R(dB) of the nanoparticles which the atomic ratio of iron and nickel is 1: 4, the absorption layer has double absorption peak, peak values are -14.6dB (9.7GHz) and -7.7dB (14.3GHz), the absorption band ranges of -10dB is from 8.5 to 11.8GHz. The reflection loss R(dB)of the nanoparticles which the atomic ratio of iron and nickel is 1: 1, 2 mm in thickness reaches to 30 dB at 12.88 GHz, the absorption band of -10dB is 9.7 ~ 14.4GHz, which has wide absorption band and excellent absorbing property.