Preparation Of FeNiMo-based Magnetic Nanomaterials And Microwave Absorption Properties

With the rapid development of electronics and science and technology,mobile phones,computers and other electronic products are widely used in human life.The wide application of electronic products has brought great convenience to people's life.At the same time,electromagnetic pollution also comes along,which has caused harm to human life and health.Therefore,in order to solve the safety problems brought by electromagnetic pollution to human health,it is urgent to find a microwave absorption material with good microwave absorption performance.Based on this,in order to further improve the microwave absorption performance of FeNiMo magnetic nano particle composites and prepare high performance FeNiMo magnetic nano particle composites Wave material,this paper takes the FeNiMo superconducting magnetic alloy with high permeability as the research object.And a series of FeNiMo magnetic nano particle composites are obtained by composition design and structure control of high permeability fenimo superconducting magnetic alloy.Firstly,this article added Mo element to FeNi magnetic nanoparticles,successfully prepared FeNiMo magnetic nanoparticles,and adjusted the dielectric constant by adjusting the ratio of powder and paraffin in FeNiMo absorber in order to obtain the best impedance match.The experimental results show that the addition of Mo element greatly improves the microwave absorption performance of FeNi magnetic nanoparticles;when powder: paraffin = 60: 40(wt.%),both the impedance matching of FeNiMo magnetic nanoparticles and the microwave absorption performance are optimal.Its minimum reflection loss value reaches-43.5 dB at 14.7 GHz,and the effective absorption width is from 12.58-16.58 GHz.Secondly,FeNiMo@NiO magnetic nanoparticle composites with different shell thicknesses and the same core are prepared by oxidative heat treatment.Under the experimental conditions of sintering temperature of 523 K for 1 h,the FeNiMo@NiO magnetic nanoparticle composite has an obvious core-shell structure,and the thickness of the shell is 5 nm,and the minimum reflection loss value reaches-54.0 dB at 12.8 GHz(d = 1.5 mm).Finally,a multiple transmission-absorption theoretical mechanism,and successfully modified the surface of FeNiMo magnetic nanoparticles by sol-gel method and solvothermal method to prepare FeNiMO@LAS,FeNiMo/RGO,FeNiMo@LAS/RGO nano-composite particles.The experimental results show that: FeNiMo nanoparticles coated with LAS are dispersed on the surface of RGO to form a dual-core-shell structure;FeNiMo@Las/RGO magnetic nanoparticles are protected from corrosion in the air by adding Las glass ceramic shell on their surface.Meanwhile,it does not significantly reduce the microwave absorption performance.When the thickness is in the range of 1-5 mm,its effective absorption(RL <-10 dB)width covers the entire band of 2-18 GHz.And the minimum reflection loss is similar to the original FeNiMo,but the absorption peak-to-peak frequency of the minimum reflection loss shifts to high frequencies.In summary,the addition of Mo element can effectively improve the microwave absorption performance of FeNi magnetic nanoparticles.In addition,the special structures such as core-shell and dual-core-shell have a great influence on the microwave absorption performance of FeNiMo magnetic nanoparticles,which can effectively improve the microwave absorption performance.