High-temperature annealing of an iron microplate with excellent microwave absorption performance and its direct micromagnetic analysis by electron holography and Lorentz microscopy

2017 ◽  
Vol 5 (24) ◽  
pp. 6047-6053 ◽  
Author(s):  
Wenbin You ◽  
Wen She ◽  
Zhengwang Liu ◽  
Han Bi ◽  
Renchao Che
Keyword(s):  
Magnetic Property ◽  
High Temperature ◽  
Microwave Absorption ◽  
Electron Holography ◽  
High Temperature Annealing ◽  
Lorentz Microscopy ◽  
Special Morphology ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Microplate iron exhibits excellent microwave absorption performance because of its special morphology and optimization of its magnetic property.

scholarly journals High-Temperature Dielectric and Microwave Absorption Property of Atmospheric Plasma Sprayed Al2O3-MoSi2-Cu Composite Coating

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1029
Author(s):  
Cheng Gao ◽  
Yangsheng Jiang ◽  
Dayong Cai ◽  
Jinyong Xu ◽  
Jia Ding
Keyword(s):  
High Temperature ◽  
Microwave Absorption ◽  
Temperature Stability ◽  
Atmospheric Plasma ◽  
High Temperature Stability ◽  
Atom Diffusion ◽  
In Situ Xrd ◽  
Air Atmosphere ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Al2O3-MoSi2 coating has excellent high-temperature stability. On this basis, Al2O3-MoSi2-Cu composite high-temperature absorbing coating was prepared by atmospheric plasma spraying method. The phase transition characteristics of Al2O3-MoSi2-Cu spraying feedstock under high temperatures were analyzed by thermogravimetric test, the phase analysis of coating was performed by an in situ XRD test at different temperatures, and the microstructure of the coating was characterized by SEM. The test results of high-temperature microwave absorption performance show that, in high-temperature air atmosphere, the Cu in the coating is gradually transformed into Cu2O by oxygen atom diffusion, and the microwave absorption performance of the coating gradually increases with the increase in temperature. The 1.7 mm-thick coating at 500 °C has the best absorbing performance with a reflection loss (RL) value of −17.96 dB and an effective absorbing bandwidth (RL < −10 dB) in X-band of 2.42 GHz. The prepared Al2O3-MoSi2-Cu composite high-temperature absorbing coating takes into account the dual advantages of high-temperature stability and high-temperature absorbing properties.

Ni-decorated SiC powders: Enhanced high-temperature dielectric properties and microwave absorption performance

2013 ◽  
Vol 237 ◽  
pp. 309-313 ◽  
Author(s):  
Jie Yuan ◽  
Hui-Jing Yang ◽  
Zhi-Ling Hou ◽  
Wei-Li Song ◽  
Hui Xu ◽  
...  
Keyword(s):  
High Temperature ◽  
Dielectric Properties ◽  
Microwave Absorption ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Negative imaginary parts of complex permeability and microwave absorption performance of core double-shelled FeCo/C/Fe2.5Cr0.5Se4 nanocomposites

RSC Advances ◽  
2016 ◽  
Vol 6 (77) ◽  
pp. 73020-73027 ◽  
Author(s):  
D. Li ◽  
Y. Feng ◽  
D. S. Pan ◽  
L. W. Jiang ◽  
Z. M. Dai ◽  
...  
Keyword(s):  
High Temperature ◽  
Microwave Absorption ◽  
Chemical Method ◽  
Arc Discharge ◽  
Complex Permeability ◽  
Discharge Process ◽  
High Temperature Solution ◽  
Temperature Solution ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Cactus-shaped core double-shelled FeCo/C/Fe2.5Cr0.5Se4 nanostructures with a spiky surface were prepared by combining an arc-discharge process with a high-temperature solution chemical method.

scholarly journals Flexible Fe3Si/SiC ultrathin hybrid fiber mats with designable microwave absorption performance

RSC Advances ◽  
2018 ◽  
Vol 8 (59) ◽  
pp. 33574-33582 ◽  
Author(s):  
Yi Hou ◽  
Yani Zhang ◽  
Xiaoqing Du ◽  
Yong Yang ◽  
Chaoran Deng ◽  
...  
Keyword(s):  
High Temperature ◽  
Microwave Absorption ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Hybrid Fiber ◽  
Fiber Mats ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Flexible Fe3Si/SiC ultrathin fiber mats have been fabricated by electrospinning and high temperature treatment (1400 °C) using polycarbosilane (PCS) and ferric acetylacetonate (Fe(acac)3) as precursors.

scholarly journals Conductive, Superhydrophobic, and Microwave-Absorbing Cotton Fabric by Dip-Coating of Aqueous Silk Nanofibers Stabilized MWCNTs and Octadecanoyl Chain Bonding

2021 ◽  
Author(s):  
Ling Liu ◽  
Mingyuan Wu ◽  
Qingyun Wu ◽  
Jiuyi Liu ◽  
Jianjun Yang ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Microwave Absorption ◽  
Cotton Fabric ◽  
Active Sites ◽  
Dip Coating ◽  
Transmission Electron Microscopy Micrographs ◽  
Coating Adhesion ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Abstract A facile dip-coating method to endow cotton fabric (CF) with satisfactory conductivity, superhydrophobicity and microwave absorption performance was proposed based on the combination of multi-walled carbon nanotubes (MWCNTs) incorporation and hydrophobic octadecanoyl chain bonding. The entanglement and bundling of MWCNTs induced by the particularly high aspect ratio and high interaction energy renders homogeneous dispersion of MWCNTs a challenging. The durable coating adhesion of MWCNTs on hydrophilic CF remains the other challenge due to the absence of strong interactions with intrinsic hydrophobic MWCNTs. In this work, silk nanofibers (SNFs) were synthesized by degrading silk at high temperature, which was adopted as dispersant to prepare individually dispersed MWCNTs via ultrasonication and homogenization processes. The coating adhesion of MWCNTs to CF (MWCNTs-CF) was enhanced via dipping coating and thermal treatment induced chemical immobilization cycles. Octadecanoyl chain-tethered MWCNTs-CF (C18-MWCNTs-CF) was manufactured by further treatment with stearoyl chloride to achieve superhydrophobicity. The scanning and transmission electron microscopy micrographs demonstrated that the aggregates of MWCNTs were successfully de-bundled into individually dispersed nanotubes by taking advantages of the high π-π interaction and electrostatic repulsive interactions between MWCNTs and SNFs. SNFs has the superiority of chemical bonding with CF at high temperature and providing active sites for subsequent hydrophobic treatment. The electrical conductivity, surface properties, thermal stability, mechanical properties, and microwave absorption performance of the CF samples were evaluated systematically. Compared with pristine CF (1.04🞩1010 Ω), the C18-MWCNTs-CF exhibited excellent conductive property with surface resistance reaching 55 Ω when the loaded MWCNTs on CF were 247.5 mg/g in the case of 3 dipping-drying cycles and possessed a relatively greater microwave absorption performance of -36.08 dB at 9.28 GHz with merely 2.7 mm thickness. Compared with pristine CF, C18-MWCNTs-CF exhibited superhydrophobicity with the WCA increasing from 26° to 150° even after 20 scratching cycles due to the combination of facile octadecanoyl group tethering and the increased surface roughness. The biodegradable and recyclable C18-MWCNTs-CF exhibited reasonable electrical conductivity, superhydrophobicity and microwave absorption that promises an ideal application prospect in the field of smart textile and wearable electronic devices.

scholarly journals Effect of Reaction Time on Microwave Absorption Properties of Fe3O4 Hollow Spheres Synthesized via Ostwald Ripening

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2921 ◽  
Author(s):  
Wei Huang ◽  
Yujiang Wang ◽  
Shicheng Wei ◽  
Bo Wang ◽  
Yi Liang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Microwave Absorption ◽  
Ostwald Ripening ◽  
Impedance Matching ◽  
Hollow Spheres ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Magnetic Structures ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Hollow magnetic structures have great potential to be used in the microwave absorbing field. Herein, Fe3O4 hollow spheres with different levels of hollowness were synthesized by the hydrothermal method under Ostwald ripening effect. In addition to their microstructures, the microwave absorption properties of such spheres were investigated. The results show that the grain size and hollowness of Fe3O4 hollow spheres both increase as the reaction time increases. With increasing hollowness, the attenuation ability of electromagnetic wave of Fe3O4 spheres increases first and then decreases, finally increases sharply after the spheres break down. Samples with strong attenuation ability can achieve good impedance matching, which it does preferentially as the absorber thickness increases. Fe3O4 hollow spheres show the best microwave absorption performance when the reaction time is 24 h. The minimum reflection loss (RL (min)) can reach −40 dB, while the thickness is only 3.2 mm.

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