Ni-Coated Carbon Nanotubes/Mn-Zn Ferrite Composite as Viable Microwave Absorbing Materials

Abstract

This paper presents the design, development and characterization of the spinel ferrite [Mn0.2Zn0.8Fe2O4] powders and Nickel (Ni)-coated multiwall carbon nanotubes (MWNTs). A combination of Mn0.2Zn0.8Fe2O4 spinel ferrites particles and Nickel (Ni)-coated multiwall carbon nanotubes (MWNTs) were introduced into epoxy resin to be a microwave absorber. The structural characterizations and surface morphology of Mn0.2Zn0.8Fe2O4 and MWNTs were investigated by X-ray diffraction (XRD) and scanning electron microscopy respectively. The electromagnetic wave absorption characteristics of the composites have been studied in the frequency interval of 12-15GHz.The results for Mn0.2Zn0.8Fe2O4/EP, Mn0.2Zn0.8Fe2O4/MWNTs/EP and Mn0.2Zn0.8Fe2O4/Ni-coated MWNTs/EP microwave absorbers for the same thickness have been reported. It has been found that the Mn0.2Zn0.8Fe2O4/Ni-coated MWNTs/EP composites show the broadband characteristics with minimum absorption of 5 dB about 2.6 GHz and the maximum absorption of 37.05 dB at 14 GHz for a coating thickness of 2 mm. Therefore, Mn0.2Zn0.8Fe2O4/Ni-coated MWNTs/EP composites will be a suitable microwave absorptive material for 12-15GHz.

Functionalized-CNT Polymer Composite for Microwave and Electromagnetic Shielding

“…According to the theory of the transmission line, the reflection loss of electromagnetic radiation RL (dB) by normal incident wave at the surface of single-layer material backed by a perfect conductor [25] can be described as Equation (1).…”

“…Where μ is the relative complex permeability, ε is the relative complex permittivity, (ω) as the frequency of the incident wave, d is the thickness of the absorbing material, and c is the speed of light in the free space. For an ideal According to the theory of the transmission line, the reflection loss of electromagnetic radiation RL (dB) by normal incident wave at the surface of single-layer material backed by a perfect conductor [25] can be described as Equation (1).…”

Fabrication and performance optimization of Mn—Zn ferrite/EP composites as microwave absorbing materials

“…The spinel ferrite, such as Mn-Zn ferrite, exhibits magneto-optical property and well matched magnetic and dielectric properties. [3,4] It can be synthesized by the traditional co-precipitation method, ceramic method, combustion method, and hydrothermal processing. [5][6][7][8] However, these methods can result in poor compositional control, size inhomogeneity, and phase impurity.…”