The Synthesis and Electromagnetic Properties of Wave-Like Ni

2012 ◽  
Vol 184-185 ◽  
pp. 1348-1351 ◽  
Author(s):  
Chao Wang ◽  
Su Rong Hu ◽  
Xi Jiang Han ◽  
Tao Zhang ◽  
Guang Ping Tang ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Microwave Absorption ◽  
Magnetic Loss ◽  
Electromagnetic Properties ◽  
Maximum Absorption

The wave-like Ni is synthesized without any impurity via varying the addition of surfactant PVP, its microwave absorption can be attributed to dielectric loss and magnetic loss, and exhibits an maximum absorption value of -14.19 dB at 14.2 GHz.

3D Fe3O4 nanocrystals decorating carbon nanotubes to tune electromagnetic properties and enhance microwave absorption capacity

2015 ◽  
Vol 3 (24) ◽  
pp. 12621-12625 ◽  
Author(s):  
Yi-Hua Chen ◽  
Zi-Han Huang ◽  
Ming-Ming Lu ◽  
Wen-Qiang Cao ◽  
Jie Yuan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Loss ◽  
Microwave Absorption ◽  
Magnetic Loss ◽  
Absorption Capacity ◽  
Electromagnetic Properties ◽  
Enhancement Effect ◽  
Multiple Interfaces

3D Fe3O4-MWCNTs, a novel nanostructure, exhibited excellent microwave absorption due to the synergy of dielectric loss and magnetic loss and the enhancement effect of multiple interfaces.

Synergetic dielectric loss and magnetic loss towards superior microwave absorption through hybridization of few-layer WS2 nanosheets with NiO nanoparticles

2020 ◽  
Vol 65 (2) ◽  
pp. 138-146 ◽  
Author(s):  
Deqing Zhang ◽  
Yingfei Xiong ◽  
Junye Cheng ◽  
Jixing Chai ◽  
Tingting Liu ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Microwave Absorption ◽  
Magnetic Loss ◽  
Nio Nanoparticles ◽  
Ws2 Nanosheets

Microwave Absorbing Properties of Fe-Filled Carbon Nanotubes/Epoxy Composite in 2-18GHz

2008 ◽  
Author(s):  
Xuchun Gui ◽  
Kunlin Wang ◽  
Jinquan Wei ◽  
Ruitao Lv ◽  
Dehai Wu
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Loss ◽  
Microwave Absorption ◽  
Electromagnetic Interference ◽  
Magnetic Loss ◽  
Magnetic Contribution ◽  
High Permittivity ◽  
Ferromagnetic Metals ◽  
Potential Applications ◽  
Iron Nanowires

Carbon nanotubes (CNTs) filled with ferromagnetic metals have potential applications of microwave absorption and electromagnetic interference shielding due to their high aspect-ratio of nanostructures that promises low percolation threshold and their inner cavities which could incorporate magnetic materials to improve the permeability and magnetic loss of composites. It has been reported that CNTs have high permittivity [1, 2]. And it could be used as dielectric microwave absorbers due to their high permittivity [3, 4]. Excellent microwave absorption should have better electromagnetic match of magnetic loss and dielectric loss. The microwave absorption could be significantly improved by matching the dielectric and magnetic contribution from respective components (e.g. CNTs and Fe) [5]. For CNTs, only dielectric loss contributes to the energy loss of microwave, while for ferromagnetic nanowires, the effect of magnetic loss becomes dominant over the dielectric loss. Either only the dielectric loss or magnetic loss may induce weak microwave absorption due to the imbalance of the electromagnetic match. Here we directly fabricated the microwave absorber by as-grown Fe-filled CNTs, which have the dielectric properties of CNTs and magnetic properties of the filled iron nanowires.

Preparation and Electromagnetic Properties of CIP/SiO2/PANI Composites

2013 ◽  
Vol 834-836 ◽  
pp. 187-190
Author(s):  
Ming Ming Wang ◽  
Zhong Lun Zhang ◽  
Wan Jun Hao ◽  
Guo Yan Hou ◽  
Zhi Jun Xin ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
In Situ Polymerization ◽  
Magnetic Loss ◽  
Electromagnetic Properties ◽  
Complex Permeability ◽  
Core Shell ◽  
Network Analyzer ◽  
Frequency Range ◽  
Xrd Patterns

CIP particles first were coated with SiO2 shell by the Stober process , then grafted the polyaniline by in-situ polymerization to prepare CIP/SiO2/PANI core-shell composites. The CIP/SiO2/PANI composites are composed the dielectric loss properties with the the magnetic loss properties, the morphologystructure and electromagnetic properties are characterized by SEMXRD and vector network analyzer, respectively. It is observed that SiO2 and PANI are on the surface of CIP particles, XRD patterns further confirm that the CIP/SiO2/PANI composites are synthesized successfully, and that interaction between components exist in the polymerization. In comparison with CIP, the complex permittivity of CIP/SiO2/PANI composites have certain enhancement in 2-18GHz frequency range, but it has a very small impact on the complex permeability.

Electromagnetic Properties and Microwave Absorption of Electrospun Fe2O3-Carbon Composite Nanofibers with Particle–Nanorod Structure

NANO ◽  
2021 ◽  
Author(s):  
Guixu Xie ◽  
Guoting Cheng ◽  
Tianyang Lv ◽  
Junqing Ma ◽  
Tingting Zhang ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Composite Nanofibers ◽  
Magnetic Loss ◽  
Carbon Composite ◽  
Absorption Efficiency ◽  
Electromagnetic Properties ◽  
Additional Absorption ◽  
Preparation Conditions ◽  
Multi Stage ◽  
Electrical Loss

Multifunctional composite nanostructure prepared via electrospinning has attracted wide attention. In this study, Fe2O3-carbon composite nanofiber with particle–nanorod structure was successfully prepared via electrospinning and followed calcination. Then, the electromagnetic properties of this material have been fully characterized, and the influence of different preparation conditions on these properties has been studied. In addition, compared to pure [Formula: see text]-Fe2O3 nanoparticles and hollow Fe2O3 nanofibers, the composite nanofibers with a thickness of 2.64[Formula: see text]mm exhibited an additional absorption peak at a frequency of 13.92[Formula: see text]GHz and an enhancement in absorption at a frequency of 15.45[Formula: see text]GHz, which may be attributed to the increase in electrical loss introduced by amorphous carbon and the enhanced magnetic loss resulting from the multi-stage reflection introduced by the particle–nanorod structure. This study shows that the composite of Fe2O3 and carbon, and the introduction of the particle–nanorod structure can improve the microwave absorption efficiency of materials, and more nanocomposites can be designed like this to further improve their electromagnetic properties and absorption efficiency in the future.

Optimum Design of Flexible Microwave Absorption Fabrics

2014 ◽  
Vol 960-961 ◽  
pp. 39-42
Author(s):  
Sai Nan Wei ◽  
Qian Li ◽  
Ji Ming Yao ◽  
Rui Fang Cui ◽  
Tian Sun
Keyword(s):  
Stainless Steel ◽  
Dielectric Loss ◽  
Microwave Absorption ◽  
Free Space ◽  
Magnetic Loss ◽  
Impedance Matching ◽  
Absorption Properties ◽  
Testing Method ◽  
Steel Core ◽  
Spun Yarn

In order to develop flexible absorption fabric and study the effects of specifications on absorption properties, two-layer laminated fabrics were designed according to thickness matching and impedance matching. Stainless steel core-spun yarn fabrics were used as first layer which easily realized matching to the free space, Ni-Fe fiber consisted of second layer because its strong dielectric loss and magnetic loss. The reflectivity of fabrics were measured by the means of "arch testing method" in the range from 2~18 GHz. The results showed that the reflectivities of laminated fabrics can below-20 dB and the bandwidth <-10dB can reach 3.88 GHz with the change of fabric specifications.

Magnetic MoS2: a promising microwave absorption material with both dielectric loss and magnetic loss properties

2020 ◽  
Vol 31 (13) ◽  
pp. 135602 ◽  
Author(s):  
Jing Wang ◽  
Xiaoyu Lin ◽  
Zengyong Chu ◽  
Zhenyu Huang ◽  
Taotao Guo ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Microwave Absorption ◽  
Magnetic Loss

Preparation and Electromagnetic Properties of Poly(o-Toluidine)-BaAl2Fe10O19 Composites

2011 ◽  
Vol 295-297 ◽  
pp. 249-255
Author(s):  
Ke Yu Chen ◽  
Meng Xi Sun ◽  
Liang Chao Li ◽  
Feng Xu ◽  
Qiu Shi Xiao
Keyword(s):  
Electromagnetic Wave ◽  
Dielectric Loss ◽  
In Situ Polymerization ◽  
Magnetic Loss ◽  
Electromagnetic Property ◽  
Electromagnetic Properties ◽  
Intrinsic Properties ◽  
Electromagnetic Wave Absorption ◽  
Testing Techniques

The poly(o-toluidine)/BaFe10Al2O19 (POT/BFA) composites were synthesized by in-situ polymerization of o-toluidine in the presence of BaFe10Al2O19 particles. The structure, composition and morphology and electromagnetic property of the obtained samples were characterized by means of modern testing techniques. The results indicated that BFA particles were coated effectively by POT polymer chain and some interactions between POT and BFA particles were existed in the composites. The conductivity and saturation magnetization of POT/BFA composites were smaller than those of pure polymers and pure BFA respectively. The POT/BFA composites had excellent magnetic loss (μ′′) and dielectric loss (ε′′) in the range of 1 MHz~3 GHz because of their intrinsic properties and synergistic effect between components. Hence, they could be recommended as candidates for electromagnetic wave absorption and shielding materials.

Microwave Absorption Properties of Fe3O4-Graphene Nanohybrids

2017 ◽  
Vol 268 ◽  
pp. 297-301 ◽  
Author(s):  
Yau Thim Ng ◽  
Wei Kong ◽  
Sivanesan Appadu ◽  
Ing Kong
Keyword(s):  
Microwave Absorption ◽  
Magnetic Loss ◽  
Impedance Matching ◽  
Low Frequency ◽  
Electromagnetic Properties ◽  
Frequency Range ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
In Situ Deposition

Magnetite (Fe3O4)-graphene nanohybrids having three different weight ratios of magnetite to graphene were synthesized by a facile in-situ deposition method. The combination of dielectric properties of graphene and magnetic properties of magnetite makes the nanohybrids an ideal choice of material for microwave absorption applications. In regards to that, the electromagnetic properties and microwave absorbing characteristics were investigated in a frequency range of 1-18 GHz. The reflection loss (RL) reaches a minimum of-40.44 dB at 6.84 GHz with a thickness of 7 mm for the sample containing 73 wt·% of Fe3O4. The bandwidth corresponding to the RL below-10 dB is 7.05 GHz. The as-prepared Fe3O4-graphene nanohybrids showed good microwave absorption ability in the low frequency band (C-band) which can be ascribed to improved impedance matching characteristics, enhanced interfacial polarizations as well as the magnetic loss contributions. Moreover, the frequency related to minimum RL could be tuned by varying the weight ratios of magnetite to graphene.

Core–Shell Structural Barium Ferrite/Polypyrrole Nanocomposites with Enhanced Microwave Absorption Properties

2020 ◽  
Vol 15 (11) ◽  
pp. 1312-1320
Author(s):  
Kai Sun ◽  
Gang Li ◽  
Yan-Hua Lei ◽  
Xin-Feng Wu ◽  
Wei-Guo Zhang ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Microwave Absorption ◽  
Barium Ferrite ◽  
Wave Attenuation ◽  
Magnetic Loss ◽  
Impedance Matching ◽  
Oxidative Polymerization ◽  
Electromagnetic Properties ◽  
Core Shell ◽  
Absorption Performance

In this paper, core–shell structural barium ferrite/polypyrrole (BF/PPy) nanocomposites were prepared by a facile in-situ chemical oxidative polymerization method, and their electromagnetic properties were systematically studied. It was demonstrated that the nanocomposites with 15 mol% BF possessed the best electromagnetic wave absorption performance, and a reflection loss of -57.13 dB was achieved at 3.98 mm. Further study revealed that the optimized impedance matching and large attenuation constant were conducive to a good absorption performance. Meanwhile, the combined action of dielectric loss and magnetic loss was responsible for the electromagnetic wave attenuation. This study provides a supplementary approach to microwave absorption materials with a desirable absorption performance.

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