JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Fang Zhang,Yuchen Cui,Jingxin Gao,Ziang Li,Yiping Yu,Yuxuan Xia,Wei Lei,Jie Zhang,Nuofu Chen,Jikun Chen
While perovskite cobaltites ( Re CoO 3 , Re : rare-earth) exhibit multiple spin states and complex electromagnetic phase diagram, their intrinsic metastability at heavy rare-earth composition ( Re H CoO 3 ) impedes their synthesis. Herein, we effectively synthesized Re H CoO 3 ( Re H = Ho, Er, and Tm), without the necessity to use the previous high pressures, by descending their reaction temperatures within molten-salts. Owing to the intermediate valence of Co 3 + , their metastable perovskites cannot be stabilized by simply elevating oxygen pressures, in contrast to the synthesis of high-transitional valence metastable perovskites such as Re NiO 3 . Alternatively, the positive formation free energy of the Re H CoO 3 was reduced by introducing KCl that dissolve the precursors at lower temperatures to prevent varying the valence of Co without scarifying the reaction kinetics. The effective synthesis of metastable Re CoO 3 towards heavy rare-earth composition further extends the range for regulating both the electronic and magnetic phases of Re H CoO 3 , paving the way to their potential electromagnetic applications.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Linjing Qiao,Jianqiang Bi,Chengjiao Che,Jiacheng Rong,Shuyong Liang
Herein, a 413-type high-entropy (Mo 0.2 Cr 0.2 Nb 0.2 Ti 0.2 V 0.2 ) 4 AlC 3 MAX phase was successfully prepared. To elucidate the influence of high-energy ball milling on microwave absorption performance, the microstructural evolution and electromagnetic characteristics of materials subjected to varying milling durations were comprehensively investigated. Via the ball-milling process, multiple reflections, polarization loss and conductive loss are largely improved due to particle size refinement, formation of thin flakes and increased shape anisotropy. Comparative analysis revealed substantial performance enhancement in samples milled for 1 h (M1) and 3 h (M3). The unmilled powders (M0) demonstrated a minimum reflection loss (RL min ) of -23.1 dB at 4.5 mm thickness and an effective absorption bandwidth (EAB) of 2.6 GHz at 5.0 mm. In contrast, M1 achieved a RL min low to -51.8 dB at 2.3 mm, while M3 exhibited an optimal EAB of 4.1 GHz at 1.06 mm. However, extending the milling duration to 6 h resulted in diminished absorption performance compared to M1 and M3, primarily due to compromised impedance matching characteristics. Therefore, via a proper ball-milling process, microwave absorption performance of high-entropy MAX phase powders can be remarkably boosted, providing a straightforward and effective approach for performance optimization in electromagnetic wave absorption applications.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
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
MATERIALS CHEMISTRY AND PHYSICS
·
2013
·
IF 2.072
Hongtao Guan,Jianbin Xie,Gang Chen,Yude Wang
One-dimensional α-MnO 2 nanorods were fabricated by using low-temperature water-bathing chemical precipitation method at 80 °C. The crystalline structures, morphological evolution process and microwave absorption properties were systematically investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and measurement of electromagnetic parameters. The results show that the morphological structures and electromagnetic properties have close relationship with the reaction time. With the prolonging of the treatment time, the as-synthesized products turn from microspheres constituted of tiny dendrites to nanorods with diameters of 20–30 nm and lengths up to 1–2 μm. The electromagnetic characterization shows that the dielectric constants and magnetic permeability values show decreasing trends with the increasing frequency, however, the dielectric and magnetic loss tangents all increase with frequency. The electromagnetic absorption properties of the products have close relationship with the morphologies and thicknesses of the samples. With a thickness of 3 mm, an absorbing peak value of −25 dB was achieved for the sample treated for 24 h. The microwave absorption properties of MnO 2 can be attributed mainly to interfacial polarization, space charge polarization and relaxation phenomena.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CARBON
·
2021
·
IF 9.594
Zhouyu Tong,Zijian Liao,Yanyan Liu,Mingliang Ma,Yuxin Bi,Weibo Huang,Yong Ma,Mingtao Qiao,Guanglei Wu
Designing one-dimensional (1D) magnetic-carbon composites microwave absorbers is a promising strategy that can meet the current demand for high-performance microwave absorption (MA) materials. In this work, hierarchical structured Fe 3 O 4 /Fe@C@MoS 2 nanofibers were successfully obtained via a simple three-step method. 1D Fe 3 O 4 /Fe@C nanofibers were fabricated through electrospinning technology and in-situ polymerization followed by carbonization and reduction in H 2 /N 2 atmosphere. MoS 2 nanosheets grew irregularly on the surface of 1D Fe 3 O 4 /Fe@C nanofibers to form the flower-like structure. The morphology, composition and magnetism of samples were systematically investigated. Furthermore, electromagnetic characteristics and MA properties of Fe 3 O 4 /Fe@C nanofibers and Fe 3 O 4 /Fe@C@MoS 2 nanofibers were compared. The minimum reflection loss (RL min ) of Fe 3 O 4 /Fe@C@MoS 2 nanofibers could reach −53.79 dB at 11.12 GHz and the corresponding absorption bandwidth (RL < -10 dB) of 4.4 GHz was achieved at the absorber thickness of 2.24 mm. This work combines electrospinning technology with traditional chemical synthesis to prepare a novel 1D core-shell microwave absorber, which provides some inspiration for preparing MA material in the future.
研究领域:
材料科学
·
电磁学
·
化学合成
✓ 已验证
DOI
高影响因子
CARBON
·
2022
·
IF 11.307
Dawei Liu,Lei Yang,Fengyuan Wang,Hao Zhang,Jia Liu,Tong Lv,Hongjie Zhao,Yunchen Du
The construction of special three-dimensional microstructure is becoming an extremely fascinating approach to upgrade the electromagnetic properties of carbon-based microwave absorption materials (MAMs) recently. Herein, we have demonstrated the successful fabrication of a series of carbon nanotubes (CNTs)@Ni/C foams (CNCFs) through two-step pyrolysis processes . It is found that the loading amount of CNTs has an obvious influence on modulating the electromagnetic diameters of CNCFs, and thus effectively tuning their microwave absorption properties . With the relative carbon content of 66.3 wt%, CNCFs-2 exhibits admirable microwave absorption performance , including the effective absorption bandwidth of 5.8 GHz with the absorber thickness of 1.8 mm and the maximum reflection loss intensity of −47.0 dB therein. Electromagnetic analysis reveals that the intrinsic attenuation ability, well-matched characteristic impedance , and multiple reflection effect synergistically work for the excellent reflection loss characteristics of CNCFs-2, which indicates rational microstructure design and appropriate chemical composition regulation are vitally important for the enhancement of microwave absorption performance. We believe these desirable microwave absorption properties can make CNCFs-2 eligible to be a very promising candidate for high-performance MAMs, and this research will provide some inspirations more or less for the development of more advanced carbon-based MAMs in the future.
研究领域:
材料科学
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电磁学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Lei Wu,Zixuan Hu,Yuan Gao,Changsheng Yue,Changbo Liu,Rock Keey Liew,Tiantian Liu,Jun Zhou
Microwave (MW) remediation of organics-contaminated soil technology offers the advantages of high efficiency and minimal damage, representing a new approach of soil thermal remediation. However, soil, being a weak MW-absorbing medium, struggles to convert MW energy into thermal energy, thus failing to attain the necessary temperature for thermal remediation. This paper prepared two new bluecoke (BC)-based modifiers (KHCO 3 @BC and KHCO 3 /MnO 2 @BC) to address temperature problem of MW remediation, as well as enhance soil quality. Their composition, structure and electromagnetic properties were analyzed to investigate their role in assisting with the MW remediation of an artificially crude oil-contaminated soil were investigated. Additionally, the industrial feasibility of MW remediation was addressed for the first time. The results showed that the KHCO 3 and MnO 2 particles in the two modifiers were covered on the BC surface and exhibited local agglomeration. Their carbon crystalline grain size increased, and the electromagnetic properties were weaker than those of the BC. Following 10 min of MW remediation assisted by KBC or KMnBC, the remediation temperatures exceeded 300 °C, with the removal rates of PHs reaching 76.16% and 88.31%, respectively. The organic matter content, soil potassium and mechanical fraction of the remediated soil were improved, but soil acidification still needed to be further addressed. The industrial application analysis indicated that the technical process and techno-economics of MW remediation of crude oil-contaminated soil were feasible, suggesting significant potential for the large-scale industrial application.
研究领域:
环境科学
·
土壤修复
✓ 已验证
DOI
PubMed
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2024
·Vol. 26
·期 14
·2400527
·
IF 3.4
Rongjuan Zhang,Qi Hu,Shaobo Yang,Song Yan,Yaxin Gu,Jiawei Ji,Zheng Zhou,Chaoze Liu,Xinran Li,Zihao Wang,Chengchun Tang
The arrival of the 5 G era has brought great benefits to our lives, but it has also brought problems such as electromagnetic radiation. Therefore, the demand for lightweight, high-performance microwave absorbing materials with wide effective bandwidth is increasing. Herein, MIL-53/g-C 3 N 4 is first synthesized from precursors of ferric chloride, terephthalic acid, and g-C 3 N 4 , and then thermally annealed at different temperatures to generate MOF-Fe@C nanocomposites. Heat treatment can effectively carbonize g-C 3 N 4 to amorphous carbon and reduce iron in MIL-53 to magnetic Fe and Fe 3 O 4 nanoparticles through carbon-thermal reduction reaction. The synergistic effect of dielectric loss of amorphous carbon and magnetic losses of magnetic particles enhances attenuation and improves impedance matching, enhancing microwave absorption. The RL min of MOF-Fe@C(4)-700 is as low as -72.78 dB at 9.44 GHz at a thickness of 3.18 mm and its effective absorption bandwidth is as broad as 4.88 GHz, covering most of X-band frequency range. The research introduces a novel technique for synthesizing absorbers with controllable electromagnetic characteristics by incorporating g-C 3 N 4 as carbon sources into MOF 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 SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 19
·1-12
·
IF 2.8
Qin Longlong,Zeng Biao,Qin Ting,Li Chen,Tang Chao,Huang Shengxiang,Deng Lianwen
Magnetic nanoparticles combined with semiconductive metal oxides are considered to be ideal candidates for electromagnetic wave absorption materials, benefiting from suitable conductivity, matched magnetism and strong polarization. In this work, Co–ZnO binary MOF (ZIF-67, ZIF-8)-based carbon composites were fabricated via a facile synthesis route. After optimization of composition and technological parameters, the synthesized nanocomposites acquired optimal electromagnetic characteristics and exhibited superb microwave absorption ability. The lowest reflection loss of the Co–ZnO–C-800 sample reached − 44.8 dB at 9.2 GHz with a thickness of 2.9 mm, and the effective absorption bandwidth (EAB) was 6.95 GHz (6.59–13.54 GHz). The microwave loss mechanism of the nanocomposite material mainly involved dielectric loss and magnetic resonance absorption. This work provides an ingenious design and synthesis strategy for novel lightweight electromagnetic wave absorbers with broadband EAB and strong 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
ACS Applied Nano Materials
·
2019
·
IF 0
Fu Chen,Hui Luo,Yongzhi Cheng,Jieling Liu,Xian Wang,Rongzhou Gong
Electromagnetic (EM) interference and radiation affecting human health and the operation of precision electronic devices have drawn considerable attention in recent years. Herein, a promising microwave-absorbing material, Ag nanoparticles (AgNPs)-decorated Fe/Fe3O4@N-doped carbon (NC) composite, was designed and fabricated with the Fe2O3@polydopamine@Ag hexagonal plates as the precursor. Crystalline structure, phase conversion, micromorphology, static magnetic properties, and EM characteristics of the samples were studied by various analytical techniques. The EM parameters of the obtained samples could be manipulated by increasing the pyrolysis temperature, exhibiting gradually enhanced dielectric and magnetic loss. Optimizing the coating thickness turns out to be a critical factor for regulating microwave absorption. The product obtained at 600 °C performs a maximum reflection loss (RL) value of −37.5 dB (10.64 GHz, 1.6 mm) and an effective absorption bandwidth (RL < −10 dB) up to 7.36 GHz (10.64–18 GHz) with a thickness of only 1.4 mm. In addition, the possible EM wave absorption mechanisms were further investigated in detail. In sum, it has been confirmed that the as-obtained AgNPs-decorated Fe/Fe3O4@NC composite with ultrabroad absorption bandwidths and strong absorption capacity would be an attractive candidate material for effective EM absorption materials in the future.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
MATERIALS LETTERS
·
2013
·
IF 2.224
Baoping Zhang,Chunxiang Lu,Hai Li
ZnO/graphene nanocomposite has been prepared by aqueous-solution and calcinations route. The electromagnetic (EM) characteristics of ZnO/graphene nanocomposite were studied by Agilent E8362B PNA vector network analyzer at 2–18 GHz. The reflection loss (RL) of ZnO/graphene nanocomposite was calculated from the EM characteristics. A RL exceeding −10 dB was obtained in the frequency range of 3.2–17 GHz with an absorber thickness of 1.5–5 mm. An optimal RL of −52 dB was found at 5.2 GHz with an absorber thickness of 3.5 mm. The excellent microwave absorption properties were a consequence of proper EM match in the microstructure as well as multi-interface polarization mechanisms.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 8
·5086-5096
·
IF 12.732
Dawei Liu,Yunchen Du,Ping Xu,Fengyuan Wang,Yahui Wang,Liru Cui,Honghong Zhao,Xijiang Han
Hierarchical microstructures are playing important roles in the design and fabrication of high-performance microwave absorbing materials (MAMs) owing to their unique advantages. In this work, a series of special “double-hierarchical” N-doped carbon nanotubes wrapping waxberry-like Ni@C microspheres (NC@NCNTs) have been rationally designed and successfully fabricated by two-step pyrolysis processes, where the loading amount of NCNTs on the waxberry-like Ni@C microspheres can be easily modulated by changing the dosage of melamine. Benefiting from sufficient attenuation ability and good impedance matching, NC@NCNTs-2, whose relative carbon content is 51.1 wt%, exhibits the best reflection loss (RL) characteristics among this series of composites, including the minimum RL intensity of −41.5 dB and an effective absorption bandwidth of 5.2 GHz with an absorber thickness of only 1.7 mm. This performance is superior to that of many homologous Ni/C composites reported previously. The investigation on EM properties indicates that the unique “double-hierarchical” architecture of NC@NCNTs can not only create stronger dipole orientation and interfacial polarization relaxation, but can also result in higher conductive loss as well as extra multiple reflection effects for incident electromagnetic waves. We believe that these results will provide some inspirations and pathways for the production of high-performance MAMs with senior microstructures in the future.
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）