Journal of Materials Chemistry C
·
2019
·Vol. 8
·期 6
·2123-2134
·
IF 6.641
Zhen Xiang,Juan Xiong,Baiwen Deng,Erbiao Cui,Lunzhou Yu,Qingwen Zeng,Ke Pei,Renchao Che,Wei Lu
Developing electromagnetic absorption materials with a strong absorption ability and wide absorption bandwidth has attracted widespread attention in the field of electromagnetic shielding, but it still remains a great challenge. Herein, we successfully developed 2D hierarchically laminated Fe3O4@nanoporous carbon (NPC)@rGO magnetic/dielectric nanocomposites as high-performance microwave absorbers through a facile microwave-assisted approach. The rational design of the composition (Fe3O4, NPC and rGO) and the hierarchical microstructure provided the nanocomposite with a micro-scale 3D magnetic coupling network, a hierarchical dielectric carbon network and good impedance matching, which were identified by the off-axis electronic holography and electromagnetic characterization. As expected, the Fe3O4@NPC@rGO composites achieved a strong reflection loss of −72.6 dB, a matching thickness of 2.0 mm and a broad bandwidth of 5.5 GHz. Such excellent achievements encourage the development of hierarchical magnetic EMA absorbers and provide remarkable inspiration for designing high-performance 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
Additive Manufacturing
·
2024
·
IF 10.3
Xinxi Zeng,Pingfan Jia,Desheng Pan,Yunlong Guo,Xiaoqing Xi,Peipei Li,Lingyun Qian,Chaoyang Sun,Ying Li,Bo Li,Ji Zhou
4D printing allows the creation of 3D-printed structures with a variety of new functionalities that respond to external stimuli, including electromagnetic properties, for which research is limited, such as terahertz resonances in ferrite materials; and therefore holding great promise for a wide range of applications. However, the limited physical properties of ferrite materials, including their anisotropic properties and limited material manipulation space, pose significant challenges to the development of ferrite materials designed for progressively increasing terahertz frequencies. Therefore, this paper proposes a platform for overcoming the limitations of terahertz resonance in ferrites through the 4D printing of metamaterials. Both the elastic and viscous moduli of the slurry are sensitive to the applied shear stress; as this stress increases, these moduli sharply decrease by several orders of magnitude, resulting in the transformation of the slurry into a fluid state similar to the liquefaction of ink. Electromagnetic coupling modes between electric dipoles and magnetic dipoles endow these ferrite metamaterials with induction and switching of terahertz resonances due to orientation stimulation. Our work sheds light on the creation of electromagnetic properties and their control by 4D printing.
研究领域:
材料科学
·
电磁学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2023
·
IF 13.1
Fei Wu,Mengyun Ling,Lei Zhang,Qiuyu Zhang,Baoliang Zhang
Herein, we propose a combination strategy to induce robust room-temperature electromagnetic coupling in non-magnetic MoS 2 semiconductor (2H–MoS 2 ). The introduction of ascorbic acid (AA) is intended to introduce sulfur vacancies ( sv ) in the process of 2H–MoS 2 nano-sheet shells coating on the surface of three-dimensional (3D) matrix. It promotes the transformation of local lattice (2H–MoS 2 ) into metal phase (1T-MoS 2 ). The transformed 1T-MoS 2 phase improves the conductivity ( σ ) of the composite by 1.48 times. Due to the Mo 4+ 4 d energy state within the bandgap, the exchange interaction between the sv and the Mo 4+ 4 d bandgap state produces a robust intrinsic electromagnetic response of more than 1.2 emu/g. Density functional theory (DFT) calculations are used to analyze the above results, and a novel electromagnetic-coupling-enhanced microwave absorption mechanism is proposed. The results indicates that microwave absorption performance can be effectively improved by the phase-incorporation effect. The minimum reflection loss (RL min ) reaches −53.1 dB (1.7 mm) and the adjustable effective absorption bandwidth (EAB) covers 14.5 GHz (3.5–18 GHz) at the various matching thicknesses. This work might shed light on a new possibility of manipulating electromagnetic interaction to promote microwave 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
RSC Advances
·
2024
·Vol. 14
·期 38
·27789-27798
·
IF 3.9
Zhipeng Xu,Yongliang Qin,Dongdong Wei,Jie Jin,Long Zheng,Jie Xu,Hui Liu,Ranran Chen,Di Wang
The study of the magnetism of tightly arranged nitronyl nitroxide (NN) radicals via Au–S self-assembly is interesting. In this study, a series of radicals (S-NN, D-NN, BS-NN, BD-NN) along with two types of nanomaterials (S-NPs, D-NPs) were synthesized. NN was chosen for the magnetic units. Their structures have been successfully synthesized and analyzed. The spin magnetic properties were characterized by electron paramagnetic resonance (EPR) and superconducting quantum interference device (SQUID) measurement. The analysis revealed that the self-assembled NN formed via Au–S bonds exhibits high packing density. Furthermore, it was gratifying to observe that the AuNPs exhibit ferromagnetism after the surface modification by NN. This results in strong ferromagnetic exchange interactions of S-NPs and D-NPs : JS-NPs = +279.715 K and JD-NPs = +254.913 K, respectively.
研究领域:
材料科学
·
磁学
·
化学合成
✓ 已验证
DOI
PubMed
高影响因子
AIP Advances
·
2024
·Vol. 14
·期 5
·
IF 1.4
Liu Peng,Ren Weijun,Guo Qing,Zhang Zhao,Zhao Xueting,Zhang Zhidong,Dai Wei,Li Bing
Cryogenic refrigeration technology based on magnetocaloric effects plays a critical role in a variety of technological applications. In this paper, we report the cryogenic magnetocaloric effects of a series of sodium-rare earth fluoride samples (Ln = Gd, Tb, Dy, Ho, Er, Tm, Yb) synthesized by the solid-state reaction method. These compounds all crystallize in a hexagonal crystal structure. Down to 2 K, no magnetic ordering was detected, while all compounds show negative Curie–Weiss temperatures indicative of strong antiferromagnetic coupling. Magnetic fields effectively suppress the magnetic fluctuations, leading to a maximum magnetic entropy change of −56 J kg −1 K −1 in NaGdF 4 at the magnetic field change from 0 to 50 kOe. These series of compounds are potentially excellent magnetic refrigerants at low temperatures.
研究领域:
物理学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Xiaoxuan He,Jintang Zhou,Jiaqi Tao,Yijie Liu,Bo Wei,Zhengjun Yao,Xuewei Tao
Magnetoelectric coupling is a key strategy to obtain high-performance microwave absorption materials. Especially for carbon matrix composites , the absorbing capacity can be optimized via the tuning of the graphitization degree and the content ratio of the magnetic and dielectric components. Based on this theory, a simple strategy, consisting of the solvothermal method and annealing in an inert atmosphere , is adopted in this study to combine CoNi magnetic alloys with graphitized carbon into micron-scale composite spherical particles. Additionally, special attention is paid to the correlation among the graphitization degree of carbon matrix, component proportion, and dielectric response ability, so as to achieve a flexible micromorphology design and a tunable microwave absorption performance. When the pyrolysis temperature is offset to the best of 700 ℃, a broadband absorption of 6.61 GHz (reflection loss < − 10 dB) is achieved at an ultrathin matching thickness of 1.9 mm. Adjusting the carbon content can further optimize the impedance matching and realize a high-intensity absorption with a reflection loss of − 72.7 dB. Our work proposes a useful strategy to realize the effective combination of the magnetic and dielectric loss mechanisms and boost the microwave absorption capacity toward achieving the desired broadband and a high-efficiency 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
Nature Synthesis
·
2025
·
IF 20
Sheng Weiming,Xie Fei,Rajeshkumar Thayalan,Zhao Yue,Jiang Yufei,Chen Wang,Ye Shengfa,Maron Laurent,Zhu Congqing
Theoretical studies predict that homoatomic metal–metal bonds of f -block actinide elements should be ubiquitous. Surprisingly, however, the isolation and characterization of compounds featuring an actinide–actinide bond has proven challenging and the field remains undeveloped. Here we report a well-defined thorium dimer featuring a Th–Th two-centre one-electron (2c-1e) σ bond and a 2c-1e π bond. This thorium dimer was synthesized by reducing a Th(IV) chloride complex with potassium metal in tetrahydrofuran. Magnetic measurements indicate that this thorium dimer features exceedingly strong antiferromagnetic coupling between the two formal Th(III) centres with a coupling constant J ≤ −1,200 cm −1 such that the Th–Th interaction has covalent bond character. Detailed computational investigations further support the existence of the Th–Th bond in this molecule. These results demonstrate that diactinide complexes with actinide–actinide bonds are accessible but require an appropriate ligand framework to stabilize low-valent actinide centres.
研究领域:
无机化学
·
理论化学
·
配位化学
✓ 已验证
DOI
高影响因子
Nano-Micro Letters
·
2024
·Vol. 16
·期 1
·1-18
·
IF 31.6
Shan Bo,Wang Yang,Ji Xinyi,Huang Yi
Two-dimensional carbon-based materials have shown promising electromagnetic wave absorption capabilities in mid- and high-frequency ranges, but face challenges in low-frequency absorption due to limited control over polarization response mechanisms and ambiguous resonance behavior. In this study, we propose a novel approach to enhance absorption efficiency in aligned three-dimensional (3D) MXene/CNF (cellulose nanofibers) cavities by modifying polarization properties and manipulating resonance response in the 3D MXene architecture. This controlled polarization mechanism results in a significant shift of the main absorption region from the X-band to the S-band, leading to a remarkable reflection loss value of − 47.9 dB in the low-frequency range. Furthermore, our findings revealed the importance of the oriented electromagnetic coupling in influencing electromagnetic response and microwave absorption properties. The present study inspired us to develop a generic strategy for low-frequency tuned absorption in the absence of magnetic element participation, while orientation-induced polarization and the derived magnetic resonance coupling are the key controlling factors of the method.
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
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2024
·Vol. 25
·期 4
·2018
·
IF 4.9
Wei Zhou,Yanhua Yao,Hailing Qin,Xiaobo Xing,Zongbao Li,Min Ouyang,Haihua Fan
In recent years, gold nanomaterials have become a hot topic in photothermal tumor therapy due to their unique surface plasmon resonance characteristics. The effectiveness of photothermal therapy is highly dependent on the shape and size of gold nanoparticles. In this work, we investigate the photothermal therapeutic effects of four different sizes of gold nanorods (GNRs). The results show that the uptake of short GNRs with aspect ratios 3.3–3.5 by cells is higher than that of GNRs with aspect ratios 4–5.5. Using a laser with single pulse energy as low as 28 pJ laser for 20 s can induce the death of liver cancer cells co-cultured with short GNRs. Long GNRs required twice the energy to achieve the same therapeutic effect. The dual-temperature model is used to simulate the photothermal response of intracellular clusters irradiated by a laser. It is found that small GNRs are easier to compact because of their morphological characteristics, and the electromagnetic coupling between GNRs is better, which increases the internal field enhancement, resulting in higher local temperature. Compared with a single GNR, GNR clusters are less dependent on polarization and wavelength, which is more conducive to the flexible selection of excitation laser sources.
研究领域:
生物医学工程
·
肿瘤学
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Yang Li,Yuchang Qing,Biao Zhao,Pengwei Bai,Rui Zhang,Haoyang Yao,Fa Luo
There are few reports on the application of Magnéli Ti 4 O 7 in the field of electromagnetic wave absorption. Herein, we designed and prepared a Ti 4 O 7 /magnetic metal composite via an electrostatic assembly with in-situ reduction reaction. This system utilized distinct magnetic coupling deriving from the subtle designed structures and magnetic-dielectric synergy. The core-shell magnetic metallic nanoparticles/oxygen deficient Ti 4 O 7 are useful microwave absorbers in terms of wide broadband, strong absorption and ultra-low filler amount. The optimal reflection loss of Ti 4 O 7 @CoNi composite was −43.6 dB at 2.5 mm, meanwhile the effective absorbing band could reach over 5.12 GHz at only a 2.7 mm thickness. The results confirm that the dependence of the electromagnetic characteristics of the absorber on the filler ratio, frequency, and absorber thickness. Therefore, this work may be beneficial in constructing core-shell structured magnetic metal/Magnéli Ti 4 O 7 composites to tune electromagnetic parameters and strengthen electromagnetic absorption.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2023
·
IF 13.1
Baojun Wang,Zijie Xu,Hao Wu,Fangzhi Huang,Fenghua Liu,Shikuo Li,Hui Zhang
Multilayered Ti 3 C 2 T x MXene , due to its tunable dielectric constants and structural designability, has been identified as rising star for exploring high-efficiency electromagnetic wave absorbers. However, it is still a huge challenge to address insufficient external contact of multilayered MXene at lower filler loading. Herein, inspired by the layer-pillar-layer architecture, a controllable catalytic-assisted nitrogen-doped carbon nanotubes bridging strategy is rationally proposed on the interlaminations of multilayered MXene units (MXene/TiO 2 /NCNTs, denoted as MTNC) to enhance dielectric dissipation ability. Through chemical vapor deposition , the NCNTs bridges as pillars not only break the confinement effect of multilayered MXene architecture like the process of seed germination but also effectively optimize impedance matching and increase dielectric constants. Simultaneously, the unique NCNTs-encapsulated magnetic components successfully prevents the agglomerations of CoNi nanoparticles and local mismatching problems, which facilitates the construction of three-dimensional magnetic coupling network. Specifically, the N heteroatoms and formed TiO 2 species induce dielectric polarization and corresponding relaxation processes. Driven by unique layer-pillar-layer architecture, optimized impedance matching, and synergistic dielectric-magnetic dissipation capabilities, the resultant absorber delivers outstanding reflection loss value of −55.8 dB and broad absorption bandwidth of 5.88 GHz. This work provides a novel structural design strategy and enlightenment for developing high-performance multilayered MXene-based absorbers.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-9
·
IF 16.6
Feng Sihua,Duan Hengli,Tan Hao,Hu Fengchun,Liu Chaocheng,Wang Yao,Li Zhi,Cai Liang,Cao Yuyang,Wang Chao,Qi Zeming,Song Li,Liu Xuguang,Sun Zhihu,Yan Wensheng
The development of two-dimensional (2D) magnetic semiconductors with room-temperature ferromagnetism is a significant challenge in materials science and is important for the development of next-generation spintronic devices. Herein, we demonstrate that a 2D semiconducting antiferromagnetic Cu-MOF can be endowed with intrinsic room-temperature ferromagnetic coupling using a ligand cleavage strategy to regulate the inner magnetic interaction within the Cu dimers. Using the element-selective X-ray magnetic circular dichroism (XMCD) technique, we provide unambiguous evidence for intrinsic ferromagnetism. Exhaustive structural characterizations confirm that the change of magnetic coupling is caused by the increased distance between Cu atoms within a Cu dimer. Theoretical calculations reveal that the ferromagnetic coupling is enhanced with the increased Cu-Cu distance, which depresses the hybridization between 3 d orbitals of nearest Cu atoms. Our work provides an effective avenue to design and fabricate MOF-based semiconducting room-temperature ferromagnetic materials and promotes their practical applications in next-generation spintronic devices.
研究领域:
材料科学
·
凝聚态物理
·
自旋电子学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）