VACUUM
·
2025
·
IF 3.9
Penggen Chen,Jianhao Wang,Xingyue Lu,Li-An Ma,Qiong Liu,Lizhen Liu,Xiaoyun Ye,Qianting Wang
To address the growing need for high-performance microwave absorbing materials in modern communication and radar technologies, this study proposes a hierarchical heterostructured engineering strategy to integrate multiple loss mechanisms and optimize electromagnetic wave absorption. The hierarchical heterostructured C/TiO 2 /Ni@C composites were constructed via in situ hydrothermal synthesis combined with high-temperature calcination. The microwave absorption properties of the composite can be tuned by adjusting the MXene doping level and pyrolysis temperature. The TiO 2 /C framework derived from MXene and porous Ni@C microspheres derived from Ni-MOF enhance dielectric losses (interfacial polarization and dipole relaxation). The precipitated Ni magnetic nanoparticles improve magnetic losses. Compared with traditional microwave absorbing materials such as single-phase carbon or metal oxides, the C/TiO 2 /Ni@C-2 composite thermally decomposed at 600 °C exhibits excellent microwave absorption properties with an optimal reflection loss of −57 dB at a thickness of 4.26 mm and a frequency of 7.1 GHz. Upon optimization to a thickness of 2.16 mm, its effective absorption bandwidth (EAB) extends to 5.34 GHz (12.43–17.77 GHz), thereby fully encompassing the Ku band. The exceptional microwave absorption performance is attributed to its distinctive magnetic-dielectric layered architecture, heterointerface synergy, and optimized impedance matching, offering critical insights for designing next-generation broadband 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
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2021
·
IF 8.067
Fan Wang,Weihua Gu,Jiabin Chen,Qianqian Huang,Mingyang Han,Gehuan Wang,Guangbin Ji
Perovskite LaCoO 3 is of great potential in electromagnetic wave absorption considering its outstanding dielectric loss as well as the existing magnetic response with the magnetic doping. However, the dissipation mechanism of the magnetic doping on the microwave absorption is lack of sufficient investigated. In this paper, LaCo 1- x Fe x O 3 ( x =0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, LCFOs) perovskites with different Fe doping amounts were prepared successfully by the sol-gel method and subsequent heat treatment in the air atmosphere. The structure characterization carried out by the first-principles calculations shows the effect of Fe doping on the dielectric and magnetic properties of LCFOs and the strong hybridization of Co/Fe-3d with O-2p in the LCFOs system was successfully demonstrated. Particularly, when x =0.1 and the thickness is only 1.95 mm, the LaCo 0.9 Fe 0.1 O 3 exhibits the best microwave absorption performance with the minimum reflection loss (RL) value of about -41 dB. The typical samples achieve a broad effective absorption bandwidth (EAB) of 5.16 GHz (7.92-13.08 GHz), which covers the total X band (8-12 GHz). Considering that, the especial Fe doping perovskite is promising to be a candidate as efficient 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
·
2023
·
IF 11
Fei Liu,Hanwei He,Lijin Cheng,Hao Li,Mohsen Abdel-Naeim Hassan Mohamed,Ning Hu,Shaojun Liu
Temperature-field-assisted vat photopolymerization has been applied to prepare Mg 2 TiO 4 ceramics with few defects and remarkably reduced dielectric loss . These excellent properties could be attributed to the significantly reduced viscosity and increased curing depth of the prepared ceramic slurry with a high solid loading when the photopolymerization temperature reaches 65 °С. Increasing the temperature helped to increase the kinetic energy of the resin molecules and reduce the viscosity of the ceramic slurry. This ensured a smooth spreading of the slurry and suppressed the formation of intra-layer defects during the printing process. Additionally, increasing the curing temperature enhanced the activation energy of the free radicals and accelerated the transfer of molecular chains , thereby increasing the polymerization rate and curing depth of the slurry. This reduced the interlayer pores of the Mg 2 TiO 4 green bodies. Thus, Mg 2 TiO 4 ceramic slurry with a high solid loading could be successfully printed by applying a temperature field. Significantly fewer defects were found in Mg 2 TiO 4 ceramics printed with 57.5 vol% solid loading than those in the samples printed with 50 vol% solid loading. The quality factor of Mg 2 TiO 4 ceramics sintered at 1550 °С for 4 h using ceramic slurries with 57.5 vol% solid loading could reach 150,000 GHz when printed at a curing temperature of 65 °С, this value is equivalent to that of dry-pressed ceramics.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2025
·Vol. 15
·期 13
·10298-10309
·
IF 4.6
Wenjuan Zhang,Xiangyue Yang,Youliang Wang,Yaxian Wang,Xuyang Wu,Yongqian Shen
As wireless communication technologies and electronic devices continue to advance quickly, electromagnetic waves (EMWs) have a serious impact on equipment interference and human health. The development of new materials for EMW absorption and shielding is crucial to mitigate electromagnetic (EM) interference. In this study, a unique strategy was implemented for developing a mesoporous polypyrrole/MXene (mPM) composite. The mPM composite was prepared by a molecular synergistic self-assembly method using spherical block copolymer micelles as templating agents to regulate mesopores. The effects of the polypyrrole/MXene ratio and pore size on the EMWs absorption performance of composites were systematically investigated. The mPM composite formed by MXene and polypyrrole exhibits a well-developed porous structure and conductive network, significantly enhancing dielectric loss. The rich mesoporous structures and the multi-layer heterogeneous interfaces can improve the interface polarization, realize multiple reflections, and enhance the EMWs absorption performance of the mPM. The mPM-1 composite, prepared using the PS100-b-PEO114 template, achieved a reflection loss (RL) of −67.82 dB at an MXene to polypyrrole ratio of 1 with a matching thickness of 1.37 mm. Its effective absorption bandwidth (EBW) was 3.68 GHz (ranging from 14.16 to 17.84 GHz) with a matching thickness of 1.25 mm. It is a reliable way to develop absorbing materials with light, thin, large EBW and high-quality EMWs absorption performance.
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
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Guangqing Zou,Heming Xu,Zhen Qi Liu,Xin Yu Qu,Guo Qiu Hou,Xue Lian Wang,Xiaolei Wang,Guimei Shi
In this work, distinct-morphological Co 3 O 4 /Nickel foams were prepared through a simple hydrothermal method and a subsequent heat treatment process. The morphology of Co 3 O 4 can be efficiently modulated from hexagonal nanosheets to nanobunches and urchin-like microspheres by manipulating the NH 4 F concentration. For the urchin-like Co 3 O 4 /Nickel foam composites, the minimum reflection loss (RL min ) value can reach −42.53 dB at a matching thickness of 2.7 mm. Theoretical analysis shows that the enhanced microwave absorption intensity is mainly originated from dielectric losses including significant interfacial polarization of the abundant interfaces, intrinsic dipoles of Co 3 O 4 and magnetic losses containing natural resonance and eddy current loss are favorable for the impedance matching. Simultaneously, multiple scattering occurring within the 3D Ni network skeleton are considered to promote the microwave absorption performance. Furthermore, a quadrilateral cone array of the resultant urchin-like Co 3 O 4 /Nickel foam composites has a RL min of −56.7 dB and an effective absorption bandwidth can achieve 9.44 GHz. This work could be beneficial for exploiting high-efficient magnetic-dielectric microwave absorption materials via the microstructural design.
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 ELECTRONIC MATERIALS
·
2021
·Vol. 50
·期 4
·2182-2189
·
IF 1.938
Feng Yefeng,Zhao Xiaomiao,Chen Peiyao,Bo Maolin,Deng Qihuang,Zhao Anning,Fu Junjie
High-dielectric-constant (high- k ) polymer–ceramic composites with low-level dielectric loss are expected to enable excellent energy storage. However, high conductivity and high dielectric loss often occur simultaneously with high dielectric constant. To obtain a high dielectric constant but with low conductivity and low dielectric loss, in this work, we studied the ternary polyvinylidene fluoride (PVDF)/La 2 TiO 5 /V 2 C dielectric composite system, which takes advantage of the synergistic effect between the high content (0 wt.% to 40 wt.%) of pseudo-perovskite filler La 2 TiO 5 and the low content (2 wt.%) of highly conductive two-dimensional filler V 2 C. Comparisons with the binary PVDF/La 2 TiO 5 composite system revealed that the ternary PVDF/La 2 TiO 5 /V 2 C composite dielectric system enabled balance and optimization of the comprehensive electrical properties of the composite material. Significantly elevated permittivity as well as depressed low-level dielectric loss were obtained in the ternary composites. The optimized ternary composite with 40 wt.% La 2 TiO 5 and 2 wt.% V 2 C exhibited high dielectric constant of 47 and low dielectric loss of 0.17 at 1 kHz. This work might enable facile fabrication of promising composite dielectric materials based on this excellent synergetic filler strategy.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 93
·90002-90009
·
IF 3.289
Zhifan Zhang,Wenhui Dang,Chengjun Dong,Gang Chen,Yude Wang,Hongtao Guan
Carbon nanotubes (CNTs)@MnOOH core–shell nanocomposites, in which the CNTs core is uniformly coated with a shell of MnOOH nanoflakes, were successfully synthesized using a facile hydrothermal method. The appearance of sodium dodecyl benzene sulfonate (SDBS) plays a key role in forming the unique CNTs@MnOOH core–shell. A high dielectric loss tangent value was observed for the samples with/without SDBS. Significantly, the CNTs@MnOOH core–shell nanocomposites exhibit an electromagnetic shielding effectiveness of 13–15 dB in the frequency range of 8–18 GHz, which can be attributed to the improved absorption loss, resulting from the increased electrical conductivity, and the improved impedance matching of the core–shell structure. Moreover, the increasing interfaces between the MnOOH and CNTs favor the electromagnetic attenuation performance. Our findings strongly confirm that the CNTs@MnOOH core–shell nanocomposites can be considered as a potential candidate for electromagnetic 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
RSC Advances
·
2016
·Vol. 6
·期 86
·83163-83174
·
IF 3.289
Hailin Mo,Genlin Wang,Fei Liu,Pingkai Jiang
Achieving a better interface between epoxy and mica particles is the key issue to realize desirable thermal conductivity and low dielectric loss in epoxy-based dielectric materials. In this paper, we report two strategies to improve the interface between synthetic mica and epoxy resin. Polymer coated mica and organically modified mica were prepared by coating polydopamine (PDA) films and grafting a silane coupling agent (KH 560) and fluoro-chemicals via self-polymerization and in situ grafting. The thermal conductivity, dielectric loss and mechanical properties of the epoxy/functionalized mica dielectric materials were markedly improved in comparison with that of the epoxy/mica dielectric materials. The results suggests that the mechanical and dielectric properties of the epoxy/functionalized mica dielectric materials both depended on a good interface and good adhesion between mica and the epoxy matrix. The thermal conductivity of the epoxy/functionalized mica dielectric materials results from a balance of interfacial thermal resistance and quality of the interface. The better overall performance of the epoxy/mica@PDA and mica@PDA@F dielectric materials is attributed to the better interface between mica and epoxy matrix, and provided a new route for preparing epoxy-based dielectric materials with high thermal conductivity and low dielectric loss for use in electronics and the electrical industry.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 22
·4006
·
IF 4.329
Qinlong Wang,Hao Wang,Caixia Zhang,Qilong Zhang,Hui Yang
High-frequency communication equipment urgently needs substrate materials with lower dielectric loss, better heat dissipation, and higher stability, to ensure real-time low-loss and high-speed signal transmission. The core-shell structure of Sr2CeO4@SiO2was prepared by the sol-gel method, and the modified powders with different volume contents were introduced into the cyclic olefin copolymer (COC) to prepare hydrocarbon resin-based composites. Due to the protective effect of the SiO2shell, the stability of the powders is significantly improved, and the moisture barrier and corrosion resistance of the composites are enhanced, which is conducive to the normal operation of electronic equipment in harsh and complex environments. When the filler content is 20vol%, the composite has a dielectric loss of 0.0023 at 10 GHz, a dielectric constant of 3.5, a thermal conductivity of 0.9 W·m−1·K−1, a water absorption of 0.32% and a coefficient of thermal expansion of 37.7 ppm/°C. The COC/Sr2CeO4@SiO2composites exhibit excellent dielectric properties and thermal conductivity, while maintaining good moisture resistance and dimensional stability, which shows potential application prospects in the field of high-frequency substrates.Keywords:polymer composite;dielectric loss;thermal conductivity;stability
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
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Aming Xie,Jiajia Wang,Cheng Zhang,Siyao Cheng
In this work, the dielectric loss behavior and electromagnetic wave absorption (EMA) property of MoO 2 ceramic from single crystal to polycrystal have been in-depth investigated. It is found that polycrystal MoO 2 shows better dielectric loss ability than single crystal MoO 2 , leading to greatly enhanced EMA performance. It is determined that polarization loss occupies the dominant position in the dielectric loss of MoO 2 ceramic. This research provides new insights in understanding of dielectric loss behavior and EMA mechanism for dielectric MoO 2 crystals.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2025
·
IF 11
Wen Lan-Chao,Guan Li,Zhang Jia-Xin,Zhu Yu-Jie,Chen Peng,Suo Jia-Lu,Zhao Biao,Zhang Rui
The solid solution formed by the combination of multiple cations has been extensively investigated due to its distinctive lattice distortion effect, which imparts unique electromagnetic properties. In particular, the regulation of dielectric and magnetic properties can be achieved through element selection. Herein, the stability of Ta x Nb 1- x C was predicted through geometric optimization of crystal structure, and Ta x Nb 1- x C nanowires were successfully synthesized through F-ion-assisted carbothermal reduction method. The introduction of bimetallic ions forms significant carbon defects and lattice distortion, which undoubtedly induces the formation of strong interface polarization and defect polarization, resulting in high dielectric loss. Furthermore, the significant presence of imperfections leads to a decrease in both the dielectric constant and conductivity, thereby achieving impedance balance. The design of a one-dimensional structure also facilitates the formation of conductive pathways, promoting carrier transitions. Benefiting from a variety of loss mechanisms and appropriate impedance matching, solid solution Ta x Nb 1- x C shows excellent electromagnetic wave absorption (EWA) performance. This research presents a promising strategy for developing single-phase materials with excellent EWA performance. Graphical abstract
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
·
2021
·Vol. 9
·期 24
·7697-7705
·
IF 7.393
Wei Luo,Yi Liu,Chuangye Wang,Dan Zhao,Xiaoyan Yuan,Lei Wang,Jianfeng Zhu,Shouwu Guo,Xingang Kong
MAX phase solid solutions have attracted considerable attention owing to their unique structure and properties. However, the synthesis of MAX phase solid solutions doped with multi-elements at M-sites still remains a challenge. Herein, a series of (V1−x−yTixCry)2AlC solid solution powders are prepared through the reactions of V, Ti, Cr, and Al metals and graphite in molten NaCl/KCl salts, and their electromagnetic (EM) wave absorption properties are systematically investigated. In comparison with Ti2AlC, V2AlC and Cr2AlC, (V1−x−yTixCry)2AlC solid solutions exhibit prominent EM absorption performance. Specifically, the minimum reflection loss (RL) value of (V0.6Ti0.2Cr0.2)2AlC is −56.2 dB at 12.07 GHz with a sample thickness of 1.75 mm, and the optimized effective absorption bandwidth (EAB, RL < −10 dB) covers the whole X band with 4.16 GHz at 2.00 mm. Furthermore, the strong dielectric resonance is presented in the range of 7–13 GHz for all (V1−x−yTixCry)2AlC, indicating that both dipole polarization and conduction loss contribute to the excellent dielectric loss of doped MAX phases. Theoretical analysis demonstrates that the polarization loss is attributed to the anisotropic conductivity of MAX phases and M-site doping, which further weakens the electric conductivity. As a result, plenty of dipoles are involved and polarization relaxation occurred when the (V1−x−yTixCry)2AlC solutions are radiated by EM. Considering the numerous kinds of MAX phase solid solutions, this work paves the way to study the EM absorption performance of high-entropy or other MAX phase solid solutions.
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）