Application of manganese dioxide to electromagnetic wave absorber: effective permittivity and absorbing property

2006 ◽  
Vol 36 (3) ◽  
pp. 235-239 ◽  
Author(s):  
H. Guan ◽  
Y. Zhao ◽  
S. Liu ◽  
S. Lv
Keyword(s):  
Electromagnetic Wave ◽  
Manganese Dioxide ◽  
Effective Permittivity ◽  
Absorbing Property

Graphene–carbonyl iron cross-linked composites with excellent electromagnetic wave absorption properties

2014 ◽  
Vol 2 (32) ◽  
pp. 6582-6591 ◽  
Author(s):  
Zetao Zhu ◽  
Xin Sun ◽  
Hairong Xue ◽  
Hu Guo ◽  
Xiaoli Fan ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Carbonyl Iron ◽  
Framework Structure ◽  
Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
The Cross ◽  
Absorbing Property

A carbon-bridge effect was adopted to explain the electromagnetic wave absorbing property related to the cross-linked framework structure of RGO–SCI composites.

Facial Synthesis of Zn-Doped Fe3O4 with Enhanced Electromagnetic Wave Absorption Performance in S and C Bands

NANO ◽  
2016 ◽  
Vol 11 (08) ◽  
pp. 1650091 ◽  
Author(s):  
Zhenfeng Liu ◽  
Honglong Xing ◽  
Lei Wang ◽  
Dexin Tan ◽  
Ying Gan ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Doping Concentration ◽  
Magnetic Loss ◽  
Sodium Dodecyl ◽  
Peak Frequency ◽  
Quarter Wave ◽  
Absorbing Material ◽  
Absorption Performance ◽  
Absorbing Property ◽  
Coating Layer Thickness

In this study, Zn-doped Fe3O4 nanoparticles were successfully synthesized by a facile solvothermal method in the presence of sodium dodecyl sulfate (SDS). The morphology, magnetic properties and electromagnetic wave absorbing properties of these materials were characterized. Results showed that Zn[Formula: see text] played a significant role in the formation of Zn-doped Fe3O4. With the protection of SDS, highly dispersed Fe3O4 nanoparticles were obtained. The nanoparticle size decreased after Zn[Formula: see text] doping, and the dispersity deteriorated with increasing Zn[Formula: see text] doping concentration. Zn-doped Fe3O4 exhibited excellent electromagnetic wave absorbing property, which resulted in magnetic loss and dielectric loss at an appropriate doping concentration. The minimum reflection loss (RL) was approximately [Formula: see text][Formula: see text]dB at 16.9[Formula: see text]GHz. As the coating layer thickness increased to 4.0[Formula: see text]mm, the bandwidth was approximately 5.0[Formula: see text]GHz corresponding to RL below [Formula: see text][Formula: see text]dB, which nearly covered the entire S band (2–4[Formula: see text]GHz) and C band (4–8[Formula: see text]GHz). The peak frequency of RL and the number of peaks matched the quarter-wave thickness criteria. It was believed that the Zn-doped Fe3O4 could be a potential electromagnetic wave absorbing material in S and C bands.

Synthesis and Electromagnetic Wave Absorbing Property of BaTiO3@Fe Nanofibers with Core-Shell Structure

2016 ◽  
Vol 23 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Young-In Lee ◽  
◽  
Dae-Hwan Jang ◽  
Ki-Hoon Sung ◽  
Kyuman Lee ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Shell Structure ◽  
Core Shell ◽  
Core Shell Structure ◽  
Absorbing Property

Tunable Pearl Necklace Structured TiO2 Spheres on Carbon Nanotubes with Enhanced Electromagnetic Wave Absorption Performance

2020 ◽  
Vol 12 (10) ◽  
pp. 1433-1440
Author(s):  
Shengnan Li ◽  
Mu Zhang
Keyword(s):  
Electromagnetic Wave ◽  
Coating Thickness ◽  
Impedance Matching ◽  
Interfacial Polarization ◽  
Absorption Frequency ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
Conduction Loss ◽  
Loading Ratio ◽  
Absorbing Property

Due to the low density and high conduction loss of carbonaceous materials, they have been considered as candidates for compositing electromagnetic wave absorbing materials. In this study, the well-designed CNT@TiO2 composites with pearl necklace structure were successfully synthesized via a facile hydrolyzation method. The absorption performances of CNT@TiO2 under different loading ratio were characterized and showed significantly different performance on the electromagnetic wave absorption. The reflection loss value reaches to –47.5 dB in the pearl necklace structured CNT@TiO2 composites obtained with a thickness of 1.6 mm at 11.2 GHz. An effective absorption bandwidth was found to reach to 4.2 GHz with a coating thickness of 1.4 mm. More, the absorption frequency range can be diverse by adjusting coating thickness. We deduce that promising electromagnetic wave absorbing property of the composites is related to the interfacial polarization induced by pearl necklace structure, improved impedance matching, conduction loss and scattering within the materials.

Simulation and Analysis of Electromagnetic Wave Manipulation by Material with Permittivity and Permeability Very near Zero

2013 ◽  
Vol 538 ◽  
pp. 101-104
Author(s):  
Lin Zhao ◽  
Zhi Gang Zhang ◽  
Lei Ding ◽  
Fneg Nie
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electromagnetic Wave ◽  
Effective Permittivity ◽  
Propagation Direction ◽  
Electromagnetic Properties ◽  
Phase Front ◽  
The Finite Element Method ◽  
Permittivity And Permeability ◽  
Element Method

Electromagnetic properties of the material with effective permittivity and permeability very near zero (double-near-zero, DNZ) have been simulated based on the finite element method and analyzed all-around. The results of simulation show that DNZ can be used to reshape the phase front of a wave perfectly. It can be used as an angular filter as well. Furthermore, The propagation direction and the shape of phase front of EM wave can be controlled by the device which is constructed by DNZ.

A double H-shaped resonator and its use as an isotropic ENG metamaterial

2009 ◽  
Vol 1 (4) ◽  
pp. 315-321 ◽  
Author(s):  
Michal Blaha ◽  
Jan Machac ◽  
Martin Rytir
Keyword(s):  
Electromagnetic Wave ◽  
Electric Field ◽  
Periodic System ◽  
Rectangular Waveguide ◽  
Mutual Coupling ◽  
Effective Permittivity ◽  
Unit Cell ◽  
Spherical Shells ◽  
2D System ◽  
Material Forming

This paper presents a new planar particle that shows negative effective permittivity under irradiation by an electromagnetic wave. The mutual coupling between the couples of these particles is studied in particular. The response of this particle sensitive to an electric field is strongly anisotropic. The particle is aimed to be used to compose an isotropic epsilon-negative metamaterial in two forms. First, a unit cell of the metamaterial consists of a cube bearing six particles on its faces, located with specific orientations. The experiments showed that this unit cell is suitable for manufacturing an isotropic epsilon-negative metamaterial obtained by arranging these cells in a 3D cubic periodic system. The second form of an epsilon-negative metamaterial with an isotropic response consists of the planar particles themselves, distributed quasi-randomly, composing a 2D system and/or of particles placed in spherical shells and distributed fully randomly in a hosting material forming a 3D system. The isotropy of these systems was verified by measurements in a rectangular waveguide.

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