Journal of Materiomics
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2022
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IF 8.589
Li Wang,Zhang Chen,Xue Wang,Liying Zhang,Zongtao Zhang,Qi Zhao,Yanfeng Gao
Low-frequency microwave absorbing materials have been challenging for many years. Three-dimensional dielectric/magnetic porous materials are beneficial for improving the low-frequency microwave absorbing performance because of natural resonance and improved impedance matching. In this study, Fe 3 O 4 @C 3D foam was prepared by carbothermal reduction method and the microwave attenuation performances and mechanisms were studied. By adjusting the content of Fe 3 O 4 @C 3D foam in paraffin composites, the low-frequency microwave attenuation capacity could be effectively optimized. The minimum reflection loss (RL min ) of paraffin composite with 40% (in mass fraction) loading exhibits −54.7 dB at 4.1 GHz for a thickness of 4.0 mm. Surprisingly, the paraffin composite with 50% (in mass fraction) loading could almost cover 2–4 GHz (S-band) in the thickness range of 3.5–5.5 mm. The strong low-frequency microwave attenuation property of Fe 3 O 4 @C 3D foam is mainly attributed to excellent low-frequency impedance matching, natural resonance, interfacial/dipole polarization, multiple reflection and scattering. This method provides a new perspective for preparing lightweight and high performance low-frequency microwave 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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
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IF 5.316
Haifeng Li,Lu Zheng,Dongdong Deng,Xialin Yi,Xiaohong Zhang,Xiang Luo,Yubo Wu,Wenjun Luo,Meijie Zhang
BaFe 12–2 x (Mn 0.5 Co 0.5 Ti) x O 19 ( x = 0, 0.5, 1.0, 2.0) powders were synthesized by a solid-state reaction (SSR) technique and its microwave absorption bandwidth was broadened by multiple magnetic resonances. The crystalline phases, microstructure, magnetic properties , and microwave (MW) absorption properties of substituted M-type barium hexaferrites (BaM, BaFe 12 O 19 ) were investigated. The refined X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images showed that all prepared samples consisted of single-phase flake shaped particles. With an increase of substitution x , the saturation magnetization ( M s ) and coercivity ( H c ) changed, resulting in a transition from hard magnetic to soft magnetic samples. The dielectric spectra and magnetic spectra of the substituted samples presented resonance at almost the same position, and multiple resonances of magnetic spectra were observed with an increase in the doping amount x , which enhanced the MW absorption and broadened the effective absorption bandwidth ( EAB ). For the x = 0.5 sample, the minimum reflection loss ( RL min ) arrived −40.2 dB, and the EABs of RL <−10 dB and RL <−20 dB widened to 7.0 GHz and 4.2 GHz respectively, with a corresponding coating thickness of 2.3 mm. The energy dissipation mechanism of all substituted samples was dominated by a dielectric resonance and natural resonance, including the contribution of exchange resonance. The BaFe 11 (Mn 0.5 Co 0.5 Ti) 0.5 O 19 is therefore a desirable candidate for electromagnetic wave (EMW) absorber applications.
研究领域:
材料科学
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电磁学
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物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
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IF 5.2
Jihui Sun,Haifeng Li,Yijian Liu,Xutao Yan,Jiabao Zang,Xiang Luo,Li Sun,Meijie Zhang
To create a spinel ferrite with excellent performance for electromagnetic (EM) wave absorption in the low frequency range of 4–6 GHz, compositions based on Co 0.75 Zn 0.125 Fe 0.125 Fe 2 O 4 (CZF–1) and Co 0.5 Zn 0.25 Fe 0.25 Fe 2 O 4 (CZF–2) with multiple elements substituted for A sites were synthesized by using solvothermal method. Hollow porous magnetic/magnetic heterostructure microspheres (HHMs) of CZF–A1 and CZF–A2 with multiple interfaces were prepared by hydrogen–thermal reduction of CZF–1 and CZF–2, and their unique structure and EM absorption properties were investigated in detail. The widest effective absorption bandwidth ( EAB ) of CZF–A1 and CZF–A2 was 4.1 GHz (13.6–17.7 GHz) and 3.7 GHz (8.0–11.7 GHz) for a corresponding thickness of 1.4 mm and 2.0 mm, respectively. In addition, the minimum reflection loss ( R.L min ) of CZF–A1 and CZF–A2 reached –49.1 dB (at f m = 13.4 GHz) and –45.0 dB (at f m = 4.2 GHz) at a thicknesses of 1.6 mm and 3.7 mm, respectively. More specifically, in the low frequency region of 4–6 GHz, CZF–A1 and CZF–A2 exhibited excellent EM wave absorption due to the effective regulation of their natural resonance frequency. The EM wave absorption frequency band of CZF–A1 and CZF–A2 samples was able to completely cover the 4–6 GHz frequency region for at coating thickness of CZF–A1 and CZF–A2 was only 3.5 mm and 3.3 mm respectively, and their R.L min reached –36.5 dB and –22.6 dB. Moreover, the absorption mechanisms of CZF–A1 and CZF–A2 including magnetic resonance, eddy current loss, interfacial polarization and dipole polarization were also investigated in detail. This research provides new insights and guidance for the development of spinel ferrite-based EM absorbers for high efficiency EM wave absorption in the low frequency (4–6 GHz) region.
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
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2020
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IF 6.444
Xueai Li,Wenqi Dong,Can Zhang,Wanchun Guo,Chunsheng Wang,Yingmei Li,Haiyan Wang
Two-dimensional microwave-absorbing materials (MAMs) with abundant preferable interfaces are highly desirable for high-performance microwave absorption. Herein, a leaf-like Fe/C structure, consisting of iron veins interpenetrated in amorphous carbon lamina, was fabricated by reducing a petal-like iron alkoxide in an H 2 /Ar atmosphere. The synthesized leaf-like Fe/C composites dissipate microwaves in an effectively similar process green to leaves absorbing sunlight. First, the unique leaf-like structure enables microwaves to pass into the composites because the 2D amorphous carbon, with its high BET surface area, provide adequate access for microwaves. Then, the incident microwave is attenuated by the distinctly improved dielectric loss caused by enhanced interface polarization and an effective magnetic loss from the natural resonance of iron. Therefore, the leaf- like Fe/C composite shows microwave absorption with a maximum reflection loss of − 59.7 dB, whose effective bandwidth (reflection loss ≤ − 10 dB) covers the whole Ku band and X band with thicknesses of only 1.5 mm and 2.0 mm, respectively.
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
·
2022
·
IF 9.965
Tianhao Liu,Kaixuan Shang,Chao Miao,Jing Ouyang
Here in this article, a halloysite nanotube/reduced graphene oxide/cobalt nickel composite (HNT/rGO/CoNi) was synthesized by co-precipitation and subsequent calcination processes. The microstructure, morphology, and chemical composition of the as-synthesized samples were characterized by X-ray diffractometer, Raman spectra, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The electromagnetic absorption performances of the composites/paraffin wax hybrids were tested in the frequency range 2–18 GHz. It was found that the synergistic attenuation of electricity and magnetism, as well as the fairly good impedance matching properties together have led to the impressive electromagnetic absorption performance of the optimized product. The maximum reflection loss can reach − 69.77 dB with the thickness of 2.38 mm at 14.72 GHz, and an effective absorption bandwidth of about 7.12 GHz (10.88 GHz–18.00 GHz) can be achieved in the HNT/rGO/CoNi (30) composite. The excellent microwave absorption performance was estimated to originate from the combination of multiple electromagnetic loss mechanisms, including interfacial polarization between graphene and magnetic nanoparticles, dipole orientation polarization caused by the defects of graphene, the natural ferromagnetic resonance, and eddy current of the magnetic nanoparticles. Furthermore, the halloysite plays the roles of improving dispersion of the magnetic nanoparticles as well as adjusting the complex permittivity of the composite. This work provides a new strategy for the design and fabrication of high performance microwave absorbing materials with natural and readily available components.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
PubMed
高影响因子
Materials Today Physics
·
2024
·
IF 10
Shanxin Li,Yijing Sun,Linyun Zhang,Xuzhou Jiang,Hongying Yu
Achieving strong low-frequency microwave absorption is an important research direction, and heterogeneous interface engineering is emerging as a promising strategy. In this work, drawing inspiration from corn, bionic corn-structured ternary nanocomposites were designed and prepared. The obtained Co 2 NiO 4 /Fe 2 O 3 /Fe 3 O 4 ternary nanocomposites mimic corn kernel structures, and create abundant heterogeneous interfaces, large specific surface area (SSA), and pores. These features effectively enhance interface polarization, optimize impedance matching, and also induce low-frequency natural resonance and high-frequency eddy current loss. The internal defects in the material can promote dipole polarization. The heterogeneous interface engineering of the corn-structured ternary nanocomposites enhances the synergistic effect of dielectric and magnetic loss in the low-frequency region. This optimization achieves an excellent microwave absorption capability of −55.16 dB at a low frequency of 4.40 GHz. Furthermore, radar cross section (RCS) simulations also verified its immense potential for practical applications. This work fabricates an original bionic nanostructure and proposes a performance optimization strategy that will provide useful guidance for the design and fabrication of low-frequency microwave absorbers.
研究领域:
材料科学
·
纳米技术
·
电磁工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Yongpeng Wang,Yingyuan Zhang,Jianan Tao,Wei Sun,Mengzhu Liu,Xuejun Cui,Haibo Zhang,Zhenhua Jiang
High-performance electromagnetic (EM) wave absorption property could be achieved by architecture design of nanomaterials . Herein, two layer hybrid Co 0.2 Fe 2.8 O 4 /carbon nanofibers with porous three-dimensional (3D) hierarchical structure were synthesized successfully through facile electrospinning, carbonization and mild chemical treatment. The Co 0.2 Fe 2.8 O 4 particles grew along the carbon nanofibers , forming the enhanced heterogeneous interfaces and high specific areas. As expected, the EM wave absorbent showed an excellent absorbing capability. The composites achieved a maximum reflection loss (RL) of −43.45 dB at 11.1 GHz with thickness of 3.0 mm. More importantly, the effective bandwidth (RL ≤ −10dB) was 5.85 GHz, covering 30% of the entire measured bandwidth. The absorption intensity and bandwidth were superior to other typical CoFe-based composites. The intrinsic mechanism of the absorption revealed that the polarization losses, magnetic losses, magnetic natural resonance and exchanged resonance losses contributed to the high-performance microwave absorption. Moreover, good impedance matching and complex transmission paths that generated from unique porous network also played an important role. This study is expected to guide future exploration on designing and synthesizing high performance EM wave absorbents.
研究领域:
材料科学
·
电磁学
·
纳米技术
·
复合材料
✓ 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）