Enhanced high-frequency absorption of anisotropic Fe3O4/graphene nanocomposites

Abstract

Anisotropic Fe3O4 nanoparticle and a series of its graphene composites have been successfully prepared as high-frequency absorbers. The crystal structure, morphology and magnetic property of the samples were detailed characterized through X-ray diffractometer (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The high-frequency absorbing performance of the composites is evaluated within 2.0–18.0 GHz. Combining reduced graphene oxide (RGO) to Fe3O4 helps to adjust the permittivity and permeability of the composite, balance the dielectric loss and magnetic loss, consequently improve the absorbing performance in view of the impedance matching characteristic. The optimal reflection loss of the pure Fe3O4 sample reaches −38.1 dB with a thickness of 1.7 mm, and it increases to −65.1 dB for the sample grafted with 3 wt.% RGO. The addition of proper content of RGO both improves the reflection loss and expands the absorbing bandwidth. This work not only opens a new method and an idea for tuning the electromagnetic properties and enhancing the capacity of high-efficient absorbers, but also broadens the application of such kinds of lightweight absorbing materials frameworks.

MWCNTs as Conductive Network for Monodispersed Fe3O4 Nanoparticles to Enhance the Wave Absorption Performances

“…As mentioned above, a high‐efficient EM wave absorbing material requires good impedance matching and absorption properties, which are associated with complex permittivity, complex permeability, thickness and bandwidth . The real part of permittivity ( ϵ′ ) and permeability ( µ′ ) represent the storage ability of EM energy, whereas the imaginary part of permittivity ( ϵ″ ) and permeability ( µ″ ) connect with the energy dissipation or loss . Dielectric loss and magnetic loss are the two mainly possible contributors, so excellent EM wave absorbing materials need the synergy of dielectric loss and magnetic loss.…”

“…Dielectric loss and magnetic loss are the two mainly possible contributors, so excellent EM wave absorbing materials need the synergy of dielectric loss and magnetic loss. In view of the impedance matching characteristic for an absorber, proper balance between the dielectric loss and magnetic loss helps to improve the absorbing performance . The Fe 3 O 4 /MWCNTs nanocomposites can effectively balance the magnetic and dielectric losses of the composites, contributing to a high absorption.…”

Manganese and Zinc Spinel Ferrites Blended with Multi-Walled Carbon Nanotubes as Microwave Absorbing Materials

“…In addition, relaxation may occur at the MZF NPs/MWCNTs interfaces, which contributes to the dielectric loss [42]. The space-charge polarization can contribute an extra relaxation, resulting in an increase of the dielectric loss to some degree [43]. For ferrite materials, it should be noted the value of ε′ is considerably bigger than that of µ′, which is related to loss tangent factors [44].…”

“…The eddy current loss is related to the electrical conductivity and the thickness of the samples. It can be expressed by X eddy [43]:…”

Polymer matrix composites as broadband radar absorbing structures for stealth aircrafts

“…studied microwave absorbing properties and magnetic properties of nano composites of thermoplastic natural rubber magnetite. Yin et al . reveled absorption properties of nano composites of Fe 3 O 4 /graphene in broad band 2–18 GHz.…”