MATERIALS & DESIGN
·
2022
·
IF 9.417
Wenqi Dong,Xueai Li,Huimin Tang,Kai Shi,Chunsheng Wang,Wanchun Guo,Kesong Tian,Haiyan Wang
The dielectric-magnetic synergistic effect can be achieved by dielectric relaxation and magnetic resonances in composites of carbon materials and magnetic particles. However, there is no direct evidence demonstrating the distribution of electromagnetic energy attenuation in the microstructure of composites. Herein, an amorphous carbon matrix with dispersed Fe/Fe 3 C@graphite-C was fabricated via a facile route. The distribution of the magnetic vector loss and electric vector loss in the hierarchical structures was revealed by numerical simulation. The content and dispersion of magnetic particles as well as the morphology of the amorphous carbon can be tuned. The 3D amorphous carbon matrix with highly dispersed Fe/Fe 3 C@graphite-C nanoparticles provided the strongest absorption of −69.0 dB and an effective response bandwidth (RL ≤ −10 dB) of 7.06 GHz. The numerical simulation revealed that the magnetic vector loss originated only from the core of Fe/Fe 3 C, and the electric vector loss was distributed throughout the structure, especially in the graphite-C shell, the interface between graphite-C and carbon nanoflakes, and the junction of different carbon nanoflakes. This work not only reveals the distribution of electromagnetic loss but also supports the theoretical analysis of the electromagnetic wave attenuation mechanism in composites, which provides direction for the future design of composites.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Zhen Xiang,Baiwen Deng,Chuang Huang,Zhicheng Liu,Yiming Song,Wei Lu
High-performance electromagnetic wave (EMW) absorbing materials have been widely used in the wireless communication and electronic devices due to their important potentials in electromagnetic attenuation. However, it is difficult to develop carbon-based absorbers with thin thickness, lightweight, and low filler loading. In this work, rationally designed hollow nanosphere γ -Fe 2 O 3 /MWCNTs composites were successfully realized for ultrathin, lightweight, and high-efficiency EMW absorbers. It showed that the composition, microstructure, and morphology of composites were tailored, which gave rise to the tunable magnetic behavior, porosity, and electromagnetic parameters. The rational design of composition and novel structure contributed to the optimization of the impedance match. The EMW attenuation was enhanced by the synergistic effects of the dielectric loss originated from the interfacial and dipole polarization, conductive loss stemmed from the 3D conductive network, and the magnetic loss derived from the eddy-current loss and ferromagnetic resonance. Accordingly, the hollow nanosphere γ -Fe 2 O 3 /MWCNTs composites with a low filling ratio of 20 wt% achieved an ultrathin matching thickness of 1.4 mm and a strong reflection loss of −63.6 dB. The substantially enhanced EMW absorbing performances were owing to the optimized impedance matching and enhanced attenuation capability. Therefore, this work can provide a paradigm for the design and synthesis of hollow nanosphere γ -Fe 2 O 3 /MWCNTs composites with an enhanced EMW absorption.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Guangjun Gou,Yu Liu,Qi Wan,Wanlu Hua,Xiaoli Xie,Bin Zhu,Zhen Tao
Three-dimensional (3D) porous carbon-based materials are commonly considered to be a hopeful microwave absorbing materials owing to their lightweight and broadband absorption. However, the structure between dissipation mechanism is still not clear. Therefore, in this work, the nitrogen-doped porous Fe 3 C@C nanocomposites derived from Fe(NO 3 ) 3 ·9 H 2 O and polyvinyl pyrrolidone (PVP) were fabricated through pre-blowing followed by in situ carbonization method with various temperatures. The obtained material treated at 600 °C, which the content of N was 4.07 %, exhibits the most excellent microwave absorption (MA) property with the minimal reflection loss of − 63.1 dB at 5.0 GHz while the matching thickness is 4.6 mm. The MA performance of the composite is originated from the synergy of magnetic-dielectric loss and improved interfacial polarization. This research provides a way to prepare high-property MA absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Linyun Zhang,Shanxin Li,Lihong Duan,Xuzhou Jiang,Yijing Sun,Hongying Yu
Core-shell structural design is an attractive strategy to achieve high-performance microwave absorbers. Nevertheless, it still remains a problem to simultaneously obtain superior microwave dissipation and impedance matching for microwave absorption (MA) materials. In this work, ZnO-NiCo 2 O 4 -NiCo 2 O 4 (ZNN) core–shell microstructure is designed and fabricated by covering NiCo 2 O 4 nanosheets on the surface of ZnO nanorod and next growth of NiCo 2 O 4 nanoparticles. With the synergies from the NiCo 2 O 4 nanosheets improving the microwave attenuation capability and the NiCo 2 O 4 nanoparticles increasing the impedance matching, ZNN possesses efficient MA performance: the strongest reflection loss is −59.93 dB at the corresponding thickness of 2.6 mm, and the maximum absorption bandwidth is 7.04 GHz at 2.4 mm, which covers the entire Ku-band. RCS simulation also indicates that ZNN has outstanding MA performance. Moreover, this study proposes a point for the utilization of nickel–cobalt oxides in MA materials, and offers a reference for the design of core–shell structural absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Hui Zheng,Runqiu Li,Shijun Dong,Wei Chen,Lining Fan,Weijia Li,Peng Zheng,Liang Zheng,Yang Zhang,Longjiang Deng
Interface modulation of graphene and magnetic particles for synergistic dielectric loss and magnetic loss is a feasible approach to realize ideal absorbing materials with a light weight, low thickness, wide bandwidth and strong absorption. In this work, an interface of iron carbide (FeC) was formed between 3D-graphene-like and Fe-coated Fe 3 O 4 particles by a vacuum heating treatment method using ferric nitrate and glucose as precursors. It is concluded that the FeC interface was formed at limited temperatures, not only producing high interface polarization but also maximizing the synergistic effect of dielectric loss in 3D-graphene-like and magnetic loss in Fe 3 O 4 . The obtained 3D-graphene/FeC/Fe/Fe 3 O 4 hybrids exhibit comprehensively optimal microwave absorption performance with a reflection loss of − 53.52 dB and a broad effective absorption bandwidth of 5.28 GHz@ <10 dB at a thickness of only 1.75 mm, showing great potential for practical applications in the field of electromagnetic absorption.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Xixi Ji,Yao Wan,Dan Xu,Xiaotong Pang,Yonggang Tong,Jingzhong Fang,Wei Xie,Yuanqiang Luo,Yaqi Ren,Yongle Hu
According to the escalating concern regarding the health hazards associated with electromagnetic radiation , the significance of absorbing materials underscores which could mitigate the healthy risks. While magnetic materials offer excellent absorption performance, their high density poses challenges to achieving optimal absorption efficiency. Conversely, carbon-based materials are known for their lightweight and versatile but face impedance matching issues. To address these obstacles, carbon/magnetic composite materials have been explored. However, their absorption performance has not fully met requirements due to weaker magnetic properties and increased density. Herein, we synthesized a porous carbon material embedded with magnetic FeNi/NiFe 2 O 4 and dielectric SiO 2 nanoparticles (FeNi-NiFe 2 O 4 -SiO 2 @PC) using carbonthermal method. By adjusting the ratio of polyvinylpyrrolidone to nitrates, the electromagnetic wave (EMW) absorption performance is adjusted. The FeNi-NiFe 2 O 4 -SiO 2 @PC composites display remarkable EMW absorption properties, achieving a minimum reflection loss of −69.9 dB at a thin thickness of 1.495 mm and a maximum effective absorption bandwidth of 5.68 GHz, covering the range from 12.32 to 18.0 GHz at a thickness of 1.92 mm. This outstanding performance can be attributed to the favorable impedance matching and the three-dimensional porous structure, which facilitates a 3D transmission network for multiple reflections. Additionally, the presence of FeNi, NiFe 2 O 4 , and SiO 2 nanoparticles enhances magnetic loss, conductive loss, interface polarization, and dipolar polarization, leading to excellent ab. Hence, this work offers insights into the composition design of high-performance absorbing materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Shijiang Feng,Rong Qiang,Yulong Shao,Lei Rong,Fangjie Ren,Na Xiao,Siyuan Zhang,Zheng Guo,Caihong Chen,Qing Miao
The construction of hollow structures and the incorporation of metal nanoparticles have been shown to be two potential approaches to achieving high-performance microwave absorption. In this study, a hollow polyhedron material featuring an FeN/Fe-doped carbon matrix was synthesized by an acidification corrosion and pyrolysis strategy. The formation of heterojunctions, coupled with the design of hollow structures, significantly improved the dielectric loss capacity of the material. Furthermore, the incorporation of magnetic metal nanoparticles not only increased the magnetic loss but also enriched the loss mechanisms of the material, leading to an overall improvement in the magnetic loss. Under the synergistic effects of these factors, the material exhibited exceptional microwave absorption properties. In particular, at a material thickness of only 2.3 mm, the minimum reflection loss value of the FeN/Fe@HC nanocomposite reached −64.5 dB with an effective absorption bandwidth of 5.1 GHz. These results further highlight the importance of a hollow structure design and metal atom doping in improving microwave absorption performance.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Chunhui Chen,Ziyang Jiang,Yu Bai,Menglin Zhai,Fengde Jia,Wenqing Hai,Minghao Li,Jinhua Jiang,Huiqi Shao,Guangwei Shao,Nanliang Chen,Siyi Bi
Developing various 3D graphene microwave absorbers is a hotspot strategy to address the issue of continuous electromagnetic pollution, but remains great challenges in realizing high-performance microwave absorption capability at thin thickness. Herein, a series of flexible metamaterial absorbers (MAs) composed of periodical laser-induced graphene (LIG) surface, dielectric substrate and metallic ground fabric from top to bottom are fabricated. The LIG meta -surface is customized by means of regulating parameters including laser power density (LPD), laser engraving rate (LER) and input patterns to well balance impedance matching and electromagnetic loss. LIG MAs exhibit minimum reflection loss (RL) of −39.7 dB (with effective absorption bandwidth (EAB) of 5.5 GHz) and maximum EBA of 12.1 GHz (with RL of −18.9 dB) at thickness less than 1.1 mm, and the simulated and experimental results are highly consistent. In addition, radar cross section (RCS) simulation of LIG MA with multi-angles endows its potential for prospective applications in in-orbit satellites electromagnetic protection.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2022
·
IF 9.463
Sinan Zheng,Zhihui Zeng,Jing Qiao,Yue Liu,Jiurong Liu
The C/MnO/Co nanocomposite fibers were prepared via a facile electrospinning and subsequent carbonization process. Co acting as the magnetic nanoparticles and MnO nanoparticles serving as impedance modulator were introduced, effectively inhibiting the agglomeration of carbon fibers during annealing. This optimizes the microstructure and significantly improves the microwave absorption performance of the nanocomposites with diameters of 250–350 nm and rough surface morphologies . The nanocomposite fibers with equal MnO and Co molar contents exhibited the minimum reflection loss of − 71.7 dB at a frequency of 14.1 GHz and an absorber thickness of 2.3 mm, and the effective absorption bandwidth reached at 6.3 GHz at a thickness of 2.6 mm. The high microwave absorption performance can be attributed to the synergistic coactions of conduction loss, magnetic loss, interfacial polarization, and multiple scatterings derived from the rational design of the constituents and microstructure of the nanocomposites.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Yanran Su,Liang Li,Dao Wang,Yang Xu,Lingling Ma,Gengping Wan,Changlong Du,Jun Liu,Ying Zhang,Qiyi Wei,Guizhen Wang
The development of electronic information technology has placed higher demands on microwave absorption materials (MAMs), especially the exploration of novel MAMs to broaden their application. At present, little attention has been given the wave absorption properties of transition metal borides (TMBs). In this work, a simple and economical method is developed to prepare Ni 3 B/Ni heterostructure nanosheets and their possible applications for microwave absorption (MA) and supercapacitor are evaluated. It is worth noting that Ni 3 B/Ni nanosheets exhibit excellent MA properties due to the aggregated nanosheet-like morphology of Ni 3 B/Ni with enhancing interfacial polarization, as well as the synergistic effect of dielectric and magnetic losses. It is observed in experiments that the minimum reflection loss value of Ni 3 B/Ni is −41.60 dB at 16.8 GHz. Moreover, the maximum effective absorption bandwidth can reach 3.28 GHz. Furthermore, Ni 3 B/Ni has good energy storage characteristics and is able to provide a specific capacity of 1150.6 F g −1 at a current density of 1 A g −1 . Meanwhile, it has the ability to maintain an initial capacity of 74.4 % after 1000 cycles at a current density of 10 A g −1 . Therefore, this study provides an idea to explore TMBs as high-performance MA and supercapacitor materials.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Physics
·
2023
·
IF 11.5
Lin Long,Xiaosi Qi,Lei Wang,Shaohong Cai,Mingsen Deng
Magnetic-dielectric nanocomposites with excellent synergetic effect were deemed as the ideal candidates for high-performance microwave absorbers (MAs). Herein, we adopted a simple hydrothermal route and hydrogenous reduction to synthesize magnetic-dielectric CoFe@MoO 2 /MoS 2 flower-like multicomponent nanocomposites (MCNCs). By controlling the different reduction temperature and time, the content of component (i.e., CoFe, MoO 2 and MoS 2 ) can be easily tuned, which is conducive to adjust electromagnetic parameter and optimize magnetic loss. Results demonstrated that the CoFe@MoO 2 /MoS 2 flower-like MCNCs could be easily regulated by simply changing the content of CoFe in favor of improved magnetic loss and optimized impedance matching. So, the prepared magnetic-dielectric CoFe@MoO 2 /MoS 2 flower-like MCNCs presented the minimum reflection loss of −55.91 dB and the widest effective bandwidth of 7.24 GHz. The strategies for adjusting rich interfaces and optimized magnetic loss are very instructive for the development of high-performance MAs and devices.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·
IF 19
Guohao Dai,Xiao You,Ruixiang Deng,Tao Zhang,Huiying Ouyang,Lixin Song
Herein, magnetic and conductive heterogeneous nickel-matrix alloy is in situ constructed in the high-entropy transition metal oxide matrix using a reductive circumstance, to form the high-temperature resistant microwave absorbers. The ohmic, dielectric polarization and magnetic loss are enhanced synergistically, prompting the improvement of loss capacity and optimization of the impedance matching feature. The composites achieve over 90% absorption in the whole Ku band with a thickness of just 1.55 mm at room temperature. Moreover, the in situ high temperature measured microwave absorption keeps stable till 500 °C. In situ characterizations are employed to investigate the evolution processes and failure mechanisms. As the temperature elevates, there are three distinct stages. The absorber goes through minor chemical reactions, consequent elimination of magnetic loss, and a rapid increase in electroconductivity. These behaviors culminate in impedance mismatch, finally worsening its absorption performance at elevated temperatures. The proposed evaluation process reveals how the above irreversible and reversible behaviors affect high-temperature microwave absorption, providing an effective theoretical basis for the design of high-temperature microwave absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）