Preparation And Absorption Properties Of Magnetic Modified Graphene

With the development and popularization of radio equipment,the threat of electromagnetic waves produced by it to people’s production and life is becoming more and more serious.Absorbing materials have become a hot material to be researched and developed urgently.Graphene has entered the field of vision of researchers because of its special twodimensional structure and excellent physical and chemical properties.However,as it is a single dielectric loss absorbing material,magnetic loss is introduced in this paper to improve its absorbing performance.In this paper,the absorbing mechanism of magnetic materials/reduced graphene oxide is studied by component design and control variable method.The absorbing properties of the material in the 2-18 GHz band were studied,and the in-situ deposited absorbing material was prepared by a simple hydrothermal method,which effectively enriched the single loss mechanism of graphene and improved the absorbing properties of the absorbing material.In this paper,using the modified GO prepared by Hummers method as the substrate,the reduction GO wideband absorbing material with in-situ growth of nickel was designed by using the characteristics of nickel oxalate deposition.Based on the reduced GO material grown by nickel in situ,the composition of magnetic particles was enriched,and the magnetic nanoparticles x Ni/y Ni O were introduced to prepare the low-frequency absorbing material of reduced GO deposited by magnetic particles in situ.Then,their properties were studied in depth using analytical tests.The effect of in-situ growth of nickel on the absorption performance of r GO and its variation rule were analyzed,and its loss mechanism was discussed in depth.The results show that the dielectric loss is mainly electric conductivity loss,and the magnetic loss is mainly eddied current loss.The dielectric loss and magnetic loss match well in the range of 12-16 GHz.At the frequency of 16.3 GHz,the optimal absorbing performance is achieved at the thickness of 2.2mm by the formula of the quarter-wavelength attenuation model,and the minimum reflection loss is calculated as-42.9d B by transmission line theory.When the reflection loss is lower than-10 d B,the effective absorption bandwidth is 10.1-18 GHz,up to 7.9 GHz.When the sample thickness is 2.4 mm,the corresponding reflection loss is lower than-10 d B,which is 8.7 GHz.The x Ni/ y Ni O-r GO low-frequency absorbing material prepared by in-situ deposition of magnetic nanoparticles x Ni/y Ni O has the corresponding dielectric loss which is parallel to the conductivity loss and relaxation polarization,and the magnetic loss is mainly eddied current loss supplemented by natural resonance.The dielectric loss and magnetic loss match well in the low frequency band.By changing the ratio of graphene oxide and magnetic particles,the corresponding low frequency band of the absorption peak can be adjusted.The maximum absorption intensity can reach-46.5 d B at the thickness of3.6 mm and frequency of 3.57 GHz.This paper has 47 figures,6 tables and 101 references.