SYNTHETIC METALS
·
2023
·
IF 4.4
Yongli Meng,Yin Liu,Chong Yang,Ling Bing Kong
Nickel ferrite/coal-based carbon (NiFe 2 O 4 /CBC) composites were synthesized by using microwave irradiation and simple hydrothermal method . The effects of reaction conditions on particle size, morphology, magnetic, and microwave absorption properties of the NiFe 2 O 4 /CBC composites were systematically studied. In all NiFe 2 O 4 /CBC composites, NiFe 2 O 4 microspheres with different shapes and sizes were anchored on the surface of CBC. By adjusting size of the NiFe 2 O 4 particles, dielectric and magnetic properties of the NiFe 2 O 4 /CBC composites could be optimized simultaneously. For the NiFe 2 O 4 /CBC sample with the average particle size of NiFe 2 O 4 to be 4.69 nm, when the thickness was 4.42 mm, the minimum reflection loss (RL min ) could reach − 63.15 dB at 9.89 GHz. Meanwhile, the maximum effective absorption bandwidth (EAB max ) was 4.91 GHz (6.31–11.22 GHz) at a thickness of 5 mm, which almost covered the whole X-band. The s-shaped hysteresis loop of the sample revealed that it had typical superparamagnetic characteristics. The possible mechanism of microwave absorption was also discussed. Our NiFe 2 O 4 /CBC composites could be used as a new and efficient microwave absorption material.
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 MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Tianming Jia,Yanling Hao,Xiaosi Qi,Yongchao Rao,Lei Wang,Junfei Ding,Yunpeng Qu,Wei Zhong
It is well recognized that interfacial effect and/or impedance matching play a great impact on microwave absorption. Herein, we proposed a facile strategy to take full advantage of interface engineering and impedance matching for boosting microwave absorption performance (MAPs). Three-dimensional (3D) hierarchical urchin-like core@shell structured NiO/Ni@CNTs multicomponent nanocomposites (MCNCs) were elaborately constructed and produced in high efficiency through a facile continuous chemical bath deposition, thermal treatment, and catalytic chemical vapor decomposition process. By controlling the pyrolysis time, the NiO/Ni@CNTs urchin-like MCNCs with different lengths and aggregation degrees of CNTs could be selectively synthesized. The obtained results revealed that the enhanced CNT contents provided abundant interfaces and effectively aggrandized their interfacial effects, which resulted in improved polarization loss, conductivity loss, and comprehensive MAPs. Impressively, the interfaces and impedance matching in the designed NiO/Ni@CNTs urchin-like MCNCs could be optimized by regulating the pyrolysis temperature, which further improved the comprehensive MAPs. And the designed NiO/Ni@CNTs urchin-like MCNCs could simultaneously display strong absorption capabilities, broad absorption bandwidths, and thin matching thicknesses. Therefore, our findings not only provided a simple and universal approach to produce core@shell structured magnetic carbon-based urchin-like MCNCs but also presented an interface engineering and impedance matching strategy to develop the tunable, strong absorption, broadband, lightweight high-efficiency 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
Optical Materials Express
·
2018
·Vol. 8
·期 11
·3319-3331
·
IF 2.566
Zilong Zhang,Xiqiao Chen,Zilin Wang,Liuyang Heng,Shuai Wang,Zhixiang Tang,Yanhong Zou
Composite microspheres with carbonyl iron cores and graphite shells are prepared by a mechanical ball milling method. The microwave absorption properties of these microspheres are investigated in terms of complex permittivity and permeability, impedance matching property, and reflection loss. The morphology and conductivity of the graphite can be well tuned by controlling the milling time to achieve the improvement in its impedance matching characteristics. In addition, by integration of the composition and unique structure, the carbonyl iron/graphite microspheres possess better absorption properties than milling graphite. The microspheres show highly strong electromagnetic wave (EMW) absorption with a minimum reflection loss (RL) of −55.2 dB, which could be attributed to the good impedance matching and effective complementarities between magnetic and dielectric components. More importantly, the qualified frequency bandwidth of the absorber is up to 9.7GHz (8.3-18GHz) with a matching thickness of 2.1mm. The results indicate that carbonyl iron/graphite microspheres may be excellent candidate materials for EMW absorption applications.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 29
·23196-23211
·
IF 2.779
Xing Honglong,Chen Wenxiong,Liu Chuang,Ji Xiaoli,Yang Ping
In this study, flower sphere alumina was synthesized autonomously by hydrothermal and annealing processes. The in situ polymerization of polypyrrole on the surface of alumina at low temperatures based on the principle of component synergy has enabled the construction of a core–shell structure for Al 2 O 3 @ppy materials, resulting in excellent electromagnetic wave absorption properties. The effect of the addition of alumina and the morphology of the materials on the microwave absorption properties of Al 2 O 3 @ppy composites was also discussed. Various methods are used for the characterization of the material. The Al 2 O 3 @ppy composites were effective in matching thicknesses of 2.5 mm with a minimum reflection loss (RL) of − 65.8 dB at a frequency of 11.52 GHz and a maximum effective absorption bandwidth (EAB) of 5.6 GHz at a matched thickness of 2.0 mm. The results show that Al 2 O 3 @ppy composites can provide a reference for EMW absorber material research.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Peijiang Liu,Vincent Ming Hong Ng,Zhengjun Yao,Jintang Zhou,Yiming Lei,Zhihong Yang,Hualiang Lv,Ling Bing Kong
In this work, two novel flowerlike NiO hierarchical structures, rose-flower (S1) and silk-flower (S2), were synthesized by using a facial hydrothermal method, coupled with subsequent postannealing process. Structures, morphologies, and magnetic and electromagnetic properties of two NiO structures have been systematically investigated. SEM and TEM results suggested that S1 had a hierarchical rose-flower architecture with diameters in the range of 4–7 μm, whereas S2 exhibited a porous silk-flower architecture with diameters of 0.7–1.0 μm. Electromagnetic performances indicated that the NiO hierarchical structures played a crucial role in determining their dielectric behavior and impedance matching characteristic, which further influenced the microwave attenuation property of absorbers based on them. Due to its hierarchical and porous architectures, S2 had higher microwave absorption performances than S1. The maximum RL value for sample S2 can reach −65.1 dB at 13.9 GHz, while an efficient bandwidth of 3 GHz was obtained. In addition, the mechanism of the improved microwave absorption were discussed in detail. It is expected that our NiO hierarchical structures synthesized in this work could be used as a reference to design novel microwave absorption materials.
研究领域:
材料科学
·
电磁学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 32
·期 21
·25725-25734
·
IF 2.22
Wang Ruoming,Bai Pengwei,Zhao Biao,Bai Zhongyi,Guo Xiaoqin,Zhang Rui
In this work, the honeycomb-like SnO 2 with excellent microwave absorbing (MA) capability was successfully prepared by a template method. Furthermore, honeycomb-like SnO 2 configuration with various pore sizes can be prepared by altering the size of polystyrene (PS) nano-sphere. The microstructure, crystallographic structure, elemental chemical state and MA properties of honeycomb-like SnO 2 were measured by Scanning electron microscopy (SEM), X-ray diffraction (XRD), Thermogravimetric-difffferential scanning calorimetry (TG-DSC) and Vector network analyzer (VNA), respectively. Interestingly, the microwave absorption properties were determined by their honeycomb configurations. Furthermore, honeycomb SnO 2 prepared using 148 nm PS spheres as template, presented a minimal RL of −47.4 dB at 11.1 GHz with the layer thickness of 3.2 mm. Meanwhile, the value of RL less than -10 dB was found in the range of 9.8–15.2 GHz. The combination of interfacial polarization, dielectric loss and cellular structure can inhibit the propagation of electromagnetic waves and dissipate microwave energy through heat or other forms. It is believed that the honeycomb-like structures could be expected to be candidates for a new generation of absorbing materials.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2021
·
IF 2.993
Zhigang Xu,Jingheng Du,Jun Wang,Zhihong Chen,Wenjun Li,Chuanbin Wang,Qiang Shen
In this work, CIP@SiO 2 , CIP@SiO 2 @ZrO 2 and CIP@void@ZrO 2 microspheres were fabricated as model samples of the core-single-shell, core-double-shell and yolk-shell absorbents to systematically compare the role of different coating structures for microwave absorption properties and offer a comprehensive reference to the rational structural design for microwave absorbents. Microstructures, magnetic properties, electromagnetic parameters and microwave absorption of different absorbents were studied. The electromagnetic absorption performance of the as-prepared multicomponent hierarchical microspheres was superior to the sole CIP, owing to the combination of strong magnetic loss of CIP core and excellent dielectric loss of SiO 2 and ZrO 2 shell. For core-double-shell CIP@SiO 2 @ZrO 2 microspheres, the minimum RL was −20.69 dB at 17.44 GHz with a thickness of 1.7 mm and the effective absorption bandwidth can reach 6.48 GHz at the coating thickness of 2 mm. It is noted that the initial oxidation temperature of CIP increased by ∼200 ℃ owing to the presence of dense SiO 2 intermediate layer. Inspiringly, the minimum RL of yolk-shell CIP@void@ZrO 2 microspheres was up to −28.38 dB at the absorber thickness of 2.2 mm and the effective absorption bandwidth reach 7.44 GHz from 10.24 to 17.68 GHz at 2.1 mm thickness. The yolk-shell structure had better absorbing performance than the core-shell structure because the cavity as the intermediate layer improved impedance matching. We believed that this work would provide a valuable reference for structural design and optimization of the high-performance absorbing materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Kun Qian,Zhengjun Yao,Haiyan Lin,Jintang Zhou,Azhar Ali Haidry,Tongbaihui Qi,Wenjing Chen,Xinlu Guo
Nanocrystalline Ni–Zn ferrites with different neodymium contents (Ni 0.5 Zn 0.5 Nd x Fe 2-x O 4 ) were synthesized by sol-gel route combined with self-propagating combustion (SPC) method. The presence of surface functional groups, crystal structure and morphology of the samples were studied by FT-IR, XRD and SEM. The results show that the prepared samples are composed of spinel phase under the condition of low neodymium content, like the pure Ni–Zn ferrite. While neodymium oxide appears after the content of Nd 3+ exceeds a certain limit (x > 0.04) and there exist two phases in the ferrite. The results of vibrating sample magnetometer (VSM) and vector network analyzer (VNA) show that adjusting the content of Nd is significant in improving the dielectric properties and microwave absorption capacity of the materials, specifically at low frequencies. When x < 0.04, the enhancement of dielectric loss ability of spinel ferrites by doping Nd 3+ is the dominant factor affecting microwave absorption ability of samples. The secondary phase Nd 2 O 3 hardly appears under this condition, thus the weakening effect of Nd 3+ addition on magnetic loss ability is not obvious. When x = 0.04, the optimal absorption peak of the material reaches −20.8 dB at 4.4 GHz with a thickness of 8.5 mm and the effective absorption bandwidth (R L < −10 dB) was 3.2 GHz. On the contrary, when x > 0.04, the magnetic loss ability decreases rapidly (e.g., Ms decreases from 82.47 emu/g to 59.77 emu/g). Meanwhile, the dielectric loss increases slowly and the microwave absorption capacity decreases.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Tongbaihui Qi,Zhengjun Yao,Jintang Zhou,Haiyan Lin,Peijiang Liu,Yiming Lei,Yuxin Zuo
In this work, a polyaniline (PANI) fibers/Co 0.2 Ni 0.4 Zn 0.4 Fe 2 O 4 (CNZF) composite (mass ratio of PANI to CNZF is 1:1) with a novel urchin-like structure was successfully fabricated through interfacial polymerization. The CNZF was synthesized by the sol-gel method, and whereafter, the PANI fibers were grafted onto the CNZF surface through in-situ polymerization. Structural and morphological properties were systematically investigated by using field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectra (FTIR). In the frequency range of 2–18 GHz, the microwave absorption properties of samples were investigated by using vector network analyzer (VNA). The results demonstrated that the microwave absorbing capability of the PANI/CNZF composite was superior to the pure CNZF or PANI. For the PANI/CNZF composite, its optimal absorption peak reached −41.9 dB at 10.48 GHz with a 2.8 mm thickness and the effective absorption bandwidth (R L < −10 dB) was 3.76 GHz. Moreover, the maximum effective bandwidth of PANI/CNZF reached 5.24 GHz (12.66–17.90 GHz) with a thinner thickness of 1.9 mm. On account of advanced impedance matching and increased interfacial effects, the PANI/CNZF composite possessed excellent microwave absorption properties and can be used as absorbers with strong absorption, extended absorbing bandwidth, and thin thickness.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Fengxin Ye,Xiaojian Guo,Yucheng Chen,Lichun Cheng,Qingrong Yao,Zhao Lu,Huaiying Zhou
In this paper, BaFe 12 O 19 (BFO) and Ce x Ba 1- x Fe 12 O 19 (CBFO- x , x = 0.1, 0.15, 0.2) were successfully synthesized using the sol-gel method. The study comprehensively explored the impact of incorporating elemental Ce on the structure and properties of barium ferrite. The results revealed that the introduction of Ce induced alterations in the microstructure of barium ferrite, enhancing its interfacial polarization and defect polarization. The interaction among ions increased the charge polarization and dipole polarization within the material. Additionally, the influence of Ce doping on the complex dielectric constant of BFO materials was investigated in this paper. The results demonstrate that Ce doping significantly enhances the dielectric performance of the material. The Cole-Cole Circle vividly illustrates the presence of multiple loss mechanisms that contribute to the dissipation of electromagnetic waves. Remarkably, the material exhibited a minimum reflection loss (RL) of −46.56 dB at x = 0.2 with a thickness of only 2.4 mm. Furthermore, at x = 0.15, the effective absorption bandwidth of the sample reached 4.16 GHz, highlighting its versatile applications. In comparison with other modifications of barium ferrite, this material offers a simple preparation process and excellent workability. The exceptional reflection loss and broad effective absorption bandwidth make it applicable across diverse fields.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2025
·Vol. 12
·期 2
·025305
·
IF 2.2
Guangyuan Yang,Jing Che,Xiaokang Zhao,Congxin Chen,Sanwen Peng,Heng Yang,Bin Zhang
The increasing complexity of electromagnetic environments demands the development of advanced absorbers with superior performance. In this study, a novel magnetic Fe3O4-modified graphene-based absorber (FARGO) is synthesized via an in situ reduction process using polyether amine. The resulting FARGO composite exhibits excellent microwave absorption properties. When the filling content of FARGO is 5 wt% in epoxy resin, the optimal reflection loss is −23.12 dB with a thickness of 4 mm and a broad absorption bandwidth of 5.6 GHz can be achieved as the thickness changes to 2 mm. Polyether amine efficiently reduces GO to rGO, significantly improving electrical conductivity. Simultaneously, it grafts amine groups onto the graphene surface, enhancing dispersion and reactivity within the epoxy resin matrix. These synergistic effects make it a promising candidate for high-performance 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 Materials Chemistry C
·
2024
·Vol. 12
·期 9
·3132-3140
·
IF 5.7
Yan Cheng,Yongzhen Ma,Zhener Dang,Luyao Han,Kai Zhou,Jiaying Zhang,Qiwei Liu,Huanqin Zhao,Ying Lin,Haibo Yang
Carbon microspheres have been widely applied in the microwave absorption (MA) field, but consecutively regulating the microstructure still remains a great challenge. In this paper, we developed a facile templated method to fabricate unique core–shell carbon@mesoporous carbon microspheres with an adjustable core and shell. By tuning the nucleation time of the carbon core, the morphology configuration can evolve from a hollow to a core–shell structure. As the nucleation time increases, the size of core carbon is gradually improved with a simultaneous reduction in the thickness of the mesoporous shell. It is confirmed that the morphology evolution of core–shell microspheres greatly affects the complex permittivity and MA performance. When the nucleation time is set as 8 h, microspheres with a moderate carbon core and mesoporous shell present efficient MA properties with a strong reflection loss intensity of −46.9 dB and wide absorption bandwidth of 7.28 GHz at a thickness of 2.4 mm. The relationship between the microstructure evolution and complex permittivity and the microwave dissipation mechanism are also investigated. This work may shed light on the microstructure regulation to optimize the dielectric ability and MA properties.
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）