Excellent microwave absorption performances of high length-diameter ratio iron nanowires with low filling ratio

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.

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Numerical study of the impact of different cooling arrangements on a high length/diameter ratio motor for electric commercial vehicle

2019 International Conference on Electrotechnical Complexes and Systems (ICOECS) ◽

10.1109/icoecs46375.2019.8949929 ◽

2019 ◽

Author(s):

Salvatore La Rocca ◽

Antonino La Rocca ◽

Adam Walker ◽

Gaurang Vakil ◽

David Gerada ◽

...

Keyword(s):

Commercial Vehicle ◽

Numerical Study ◽

Diameter Ratio ◽

The Impact ◽

High Length

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Analysis of Aerodynamics Characteristic of High Length-to-Diameter Ratio Missile

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.327.153 ◽

2011 ◽

Vol 327 ◽

pp. 153-158

Author(s):

Zhi Ling Peng

Keyword(s):

Elastic Vibration ◽

Diameter Ratio ◽

The Stability ◽

High Length ◽

Length To Diameter Ratio

On the basis of analysis of aerodynamics characteristic of high length-to-diameter ratio missile on the fly, Study the stability of elastic vibration.

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Numerical Modeling of High Length-to-Diameter Ratio Riser Subjected to VIV

10.4043/28635-ms ◽

2018 ◽

Author(s):

M. C. Kara ◽

V. Jaiswal ◽

P. P. Sharma ◽

B. Tulimilli ◽

S. Cosgrove

Keyword(s):

Numerical Modeling ◽

Diameter Ratio ◽

High Length ◽

Length To Diameter Ratio

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Study on Al-Doped ZnO Nanofibers Prepared by Electro-Spinning Technique

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.301-303.55 ◽

2011 ◽

Vol 301-303 ◽

pp. 55-59

Author(s):

Qin Li ◽

Hai Ming Zhang

Keyword(s):

Zinc Acetate ◽

Sol Gel ◽

Hexagonal Structure ◽

Diameter Ratio ◽

Electrospinning Technique ◽

Emission Properties ◽

Uv Emission ◽

Zno Nanofibers ◽

Doped Zno ◽

High Length

PVA/ zinc acetate sol–gel were fabricated into thin PVA/ zinc acetate composited fibers films by using electrospinning technique. After annealing of the above precursor fibers, ZnO:Al nanofibers with a diameter of 100-700 nm and high length-diameter ratio were obtained successfully. The ZnO:Al nanofibers were characterized by XRD, SEM, and PL, respectively. The XRD results show that Al-doped ZnO nanofibers present ZnO hexagonal structure. PL spectra display that the ZnO: Al nano-fibers have a strong UV emission properties.

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Study on the Properties of Microwave Absorption of Zinc Oxide Whisker

Materials Science Forum ◽

10.4028/www.scientific.net/msf.510-511.982 ◽

2006 ◽

Vol 510-511 ◽

pp. 982-985 ◽

Cited By ~ 1

Author(s):

Long Sheng Chu ◽

Zuo Wan Zhou ◽

Yong Zhao

Keyword(s):

Zinc Oxide ◽

Microwave Absorption ◽

Cross Section ◽

Absorption Efficiency ◽

Microwave Energy ◽

Diameter Ratio ◽

Tunnel Effect ◽

Conductive Network ◽

Pure Zinc ◽

Oxide Whisker

In this paper, the microwave absorption behaviors of zinc oxide whisker were studied. The morphological structure of zinc oxide whisker was observed through scanning electron microscope. The effect of the structure of zinc oxide whisker on the microwave absorption, such as length-diameter ratio, cross-section appearance, and doping was analyzed. The result shows that the more irregular the cross section of the needle of zinc oxide whisker is, the more prominent the microwave absorption appears. The less the length-diameter ratio of the needle of zinc oxide whisker is, the more obvious the microwave absorption of zinc oxide whisker becomes. The zinc oxide whisker, which had inlet ion, such as Al3+, Fe3+ , etc., in its crystal lattice has a better microwave absorption efficiency than the pure zinc oxide whisker. The further analysis found that electric conductive network can be formed easily because of the zinc oxide whisker, and the coating had the porous structure. When microwave reaches the coating of zinc oxide whisker, the polarization of zinc oxide whisker was resulted and the electromagnetic energy lost. Firstly, electric current was transmitted through the electric conductive network and the energy transformed to heat. Secondly, tips’ phenomenon has been observed, which lead to the energy lost. Finally, the microwave energy was lost because of the tunnel effect, which will bring about leakage current. Based on the three reasons above, microwave energy was absorbed by the coating containing the zinc oxide whisker.

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Preparation of Acicular-Like ZnO Nanostructured Powder Using Ball Mill Zinc Powder by Hydrothermal Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.833.80 ◽

2013 ◽

Vol 833 ◽

pp. 80-83

Author(s):

Wei Xiao Peng ◽

Kai Jun Wang ◽

Jin Hu ◽

Yu Tian Wang

Keyword(s):

Hydrothermal Method ◽

Ball Mill ◽

High Energy ◽

Zinc Powder ◽

Diameter Ratio ◽

High Dispersion ◽

Hydrothermal Temperature ◽

Zno Nanostructure ◽

High Length ◽

Length To Diameter Ratio

In this paper, we demonstrated the acicular-like ZnO nanostructure powder were prepared by hydrothermal method. We used the industrial aerosol elemental zinc powders through high energy ball mill, and then took ball mill zinc powder into autoclave reactor direct synthesis high length to diameter ratio of acicular-like ZnO nanostructure powder. The samples phase were studied by XRD, the morphology of the sample were observed by SEM, the samples of luminous performance were studied by Fluorescence spectrophotometer. When the hydrothermal temperature is 200°C, hydrothermal time is 24 h, mineralizer of NaOH concentration is 1 mol/L, the samples were washed by alcohol and then dried at 80°C for 3 hours. We had synthesized the high dispersion, high length to diameter ratio up to 50 acicular-like ZnO nanostructure powder.

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Melamine-induced formation of carbon nanotubes assembly on metal-organic framework-derived Co/C composites for lightweight and broadband microwave absorption

Dalton Transactions ◽

10.1039/d1dt00655j ◽

2021 ◽

Author(s):

Wei Liu ◽

Pengtao Duan ◽

Chao Mei ◽

Kun Wan ◽

Bowei Zhang ◽

...

Keyword(s):

Carbon Nanotubes ◽

Microwave Absorption ◽

Metal Organic Framework ◽

Filling Ratio ◽

Complex Structures ◽

Absorption Bandwidth ◽

Microwave Absorbing Materials ◽

Absorbing Materials ◽

Metal Organic ◽

Organic Framework

To extend effective absorption bandwidth at low filling ratio is still a challenge for metal-organic framework-derived microwave absorbing materials. Herein, varied complex structures based on CNTs have been built on...

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