JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·
IF 3.8
Wen-Bo Li,Li-Xia Pang,Xiao-Long Wang,Wei-Guo Liu,Xiaogang Yao,Huixing Lin,Jin-Chao Miao,Di Zhou
This study examines the microwave dielectric properties of the Na 2 O–Bi 2 O 3 –Ln 2 O 3 –MoO 3 (Ln = Sm and Y) system, synthesized via a solid-state process at ultra-low sintering temperatures ranging from 600°C to 660°C. The X-ray diffraction and Rietveld refinement results suggested that a tetragonal sheelite phase was found in the x Na 5 Bi(MoO 4 ) 4 –(1− x )Na 5 Ln(MoO 4 ) 4 (0.05 ≤ x ≤ 0.20) ceramics. Scanning electron microscopy (SEM), backscattered electron image (BSE) and energy dispersive spectrometer (EDS) results indicated that the complex substitution of Bi 3+ produced a significant effect on the microstructural morphology. Besides, the substitution of Bi 3+ for (Sm 0.3 Y 0.7 ) 3+ effectively reduced the sintering temperature to 630°C. The variation of theoretical dielectric polarizabilities (α theo. ), the polarizability density (α theo. / V m ), the observed dielectric constant (ε r ), theoretical dielectric constant (ε theo. ), packing fraction (PF) values, and bond valence ( V i ) as a function of x value were investigated, which was helpful for understanding microwave dielectric properties. The ceramic composition 0.1Na 5 Bi(MoO 4 ) 4 –0.9Na 5 Ln(MoO 4 ) 4 sintered at 630°C for 2 h demonstrated the best microwave dielectric properties, exhibiting a ε r ∼ 9.3, Q × f value of about 31,200 GHz (at 11 GHz) and a temperature coefficient (τ f ) of −41.3 ppm/°C. Both XRD and EDS results indicated that the 0.1Na 5 Bi(MoO 4 ) 4 –0.9Na 5 Ln(MoO 4 ) 4 ceramic was chemically compatible with Ag at its sintering temperature (630°C). The x Na 5 Bi(MoO 4 ) 4 –(1− x )Na 5 Sm 0.3 Y 0.7 (MoO 4 ) 4 (0.05 ≤ x ≤ 0.20) ceramics in the Na 2 O–Bi 2 O 3 –Ln 2 O 3 –MoO 3 (Ln = Sm and Y) system are promising candidates for 5G and its successor 6G mobile communication technology.
研究领域:
材料科学
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电子陶瓷
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微波通信
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Zihang Zhang,Zixuan Wang,Yanjun Zhang,Peiyuan Zou,Mingyang Zhu,Shuangshuang Li,Xinwei Tang,Yezi Lu,Wei Li,Kaixin Lai,Wei Hong,Yufei Li,Xu Zhang,Zicheng Wang,Tianxi Liu
With the rapid development of 5G technology, the types and numbers of 5G base stations are becoming increasingly large. The precision electronic devices in base stations are at risk of electromagnetic interference and infrared detection. Therefore, it is of great significance to design lightweight and high-strength protective materials with electromagnetic dissipation and infrared stealth performance. In this paper, a rigid polymethacrylimide (PMI) composite foam is fabricated by in-situ copolymerization and free-foaming process. Stable polymerization of PMI and uniform dispersion of CNT are steady controlled. The appropriate pore size and density effectively enhance mechanical properties of PMI/CNT composite foam (PCF). More importantly, the hierarchical impedance matching can be constructed by systematically assembling PCF and silver coating (Ag), endowing it with a low-reflection electromagnetic dissipation performance. Thickness of the composite material can be effectively reduced. In addition, thermal insulation of PCF and low infrared-emissivity of Ag coating bring an excellent infrared stealth performance for PCF/Ag. Such excellent comprehensive performance makes it desirable to be applied as protection material for 5G base stations.
研究领域:
材料科学
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电磁学
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隐身技术
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Shuai Zhu,Xin Wang,Yuhui Li,Xiaochi Lu,Liang Cao,Lei Yu,Zhefei Wang
Novel barium feldspar-based microwave dielectric ceramics derived from graphite tailings (BAS-GT) were prepared via the solid-state reaction method. The effects of Sr 2 + substitution on the phase composition, microstructure and microwave dielectric properties of sintered ceramics were investigated. Results demonstrated that the barium feldspar solid solution co-existed with Ca 2 Al 2 SiO 7 when excess Sr 2+ was introduced. The Sr 2+ substitution effectively improved the densification and microwave dielectric properties of the BAS-GT ceramics, especially the quality factor ( Q × f ) and temperature coefficient of resonant frequency ( τ f ), attributed to the optimised phase composition and good sintering behaviour. A component standard for utilising graphite tailings in microwave dielectric ceramics was established. The 10 mol% Sr 2+ substituted BAS-GT ceramic samples sintered at 1150 °C exhibited optimised microwave dielectric properties, with εᵣ = 7.13, Q × f = 28,452 GHz, and τ f = –27.12 ppm/°C, indicating significant potential of these ceramics for applications in 5 G wireless communication technology.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Huan Liu,Yu Liu,Xueqing Yu,Minmin Mao,Bing Liu,Hadi Barzegar Bafrooei,Aihua Li,Yuanyuan Zhang,Ehsan Taheri-Nassaj,Kaixin Song,Wenjun Li,Ian.M. Reaney
New ultra-low loss, temperature-stable composite ceramics, (1- x ) Mg 1.99 Ga 0.01 Si 0.99 Al 0.01 O 4 - x CaTiO 3 , have been developed with a view to expanding the portfolio of low-cost, MW dielectrics available for 5 G/6 G telecommunications, currently dominated by 95 wt%MgTiO 3 -5 wt%CaTiO 3 , (Mg,Ca)TiO 3 (relative permittivity, ε r ∼ 21, quality factor, Q × f ∼ 56,000 GHz and temperature coefficient of resonant frequency, τ f ∼ 0 ppm/°C). Compared with (Mg,Ca)TiO 3 , 89 wt%Mg 1.99 Ga 0.01 Si 0.99 Al 0.01 O 4 -11 wt%CaTiO 3 ceramics are also temperature stable ( τ f = −2.72 ppm/°C) but have lower ε r (∼8.55) and a higher Q × f (∼ 72,900 GHz @ 12 GHz and 80,900 GHz @ 26 GHz), better suited to the higher frequencies earmarked for 6 G millimeter-wave (mm-wave) applications. To demonstrate its potential for 5 G/6 G telecommunications, a waveguide filter with novel negative coupling structure was fabricated based on simulated results. The filter had low insertion loss (0.43 dB) at the center frequency (4.8 GHz) and high selectivity with a roll-off rate of 576/375 dB/GHz. The S-parameters matched well at 25 °C and 85 °C, demonstrating that the filter had excellent temperature stability and was therefore suitable for future 5 G/6 G microwave and mm-wave communication devices.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 28
·9527-9538
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IF 6.4
Shuaizhen Li,Zhibo Zheng,Siwei Liu,Zhenguo Chi,Yi Zhang,Jiarui Xu
Graphite films are widely used in microelectronic devices as heat-dissipation materials due to their high thermal conductivity, low thermal expansion coefficient and lightweight. In the 5G era, the miniaturization and integration of microelectronic devices are continuously improving, so there are higher requirements for heat-dissipation materials. Therefore, flexible graphite films with high thermal conductivity are urgently needed. In this work, nickel-coated CNTs (Ni@CNTs) were prepared first as additives to be incorporated into the PI matrix via in situ polymerization, and then the Ni@CNTs/PI composite films were carbonized and graphitized at high temperature to form graphite films. In this composite system, nickel particles can effectively improve the graphitization degree of the obtained graphite films, which is beneficial to the improvement of their thermal conductivity, as well as the CNTs can effectively enhance the cross-plane thermal conductivity and mechanical strength of the graphite films. The graphite films obtained from the graphitization of PI/Ni@CNTs (0.4 wt%) have a perfect graphene structure and optimal properties. The optimal layer thickness of graphene is 0.3354 nm, while the d-spacing of the graphite layers is around 0.3358 nm. The in-plane thermal conductivity is 1.13 times greater than that of the graphite film made from the pure PI film (G0 film), which has a value of 1198.5 W m−1 K−1. The cross-plane thermal conductivity is 6.26 W m−1 K−1, which is 2.96 times that of the G0 film (2.11 W m−1 K−1). The bending strength is 72.3 Mpa, which is 2.28 times that of the G0 film (31.7 Mpa). The introduction of Ni@CNTs greatly improves the comprehensive properties of graphite films, and the preparation technology has an important guiding significance for the preparation of high thermal conductivity flexible graphite films and important industrial application value.
研究领域:
材料科学
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热管理技术
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.7
Jian Li,Peilin Qing,Weishuang Fang,Yang Yang,Yuandong Qin,Huaicheng Xiang,Ying Tang,Liang Fang
Two tetragonal scheelite Ag 0.5 RE 0.5 MoO 4 (RE = Nd, Y) ceramics with space group I 4 1 / a were synthesized via the solid-state reaction method. Ag + and RE 3+ co-occupy the dodecahedral A-site, while Mo 6+ occupies the tetrahedral B-site. Ag 0.5 Nd 0.5 MoO 4 sintered at 825 ℃ shows a higher Q × f of 92,000 GHz, with ε r = 12.14 and τ f = -62.85 ppm/℃. Ag 0.5 Y 0.5 MoO 4 sintered at 850 °C exhibits ε r = 12.96, Q × f = 56,000 GHz, and τ f = -46.22 ppm/℃. The structure-property relationship was systematically investigated using bond valence, ionic polarizability, Raman spectroscopy, and P-V-L chemical bond theory. The larger deviation Δ ε r in Ag 0.5 Y 0.5 MoO 4 originates from the stronger overall cation rattling effect and the insufficient average ionic bonding caused by its more negative weighted average deviation factor < d > . Q × f is strongly dependent on lattice vibration damping, conductive activation energy, lattice energy, and stability of rare-earth ions. Positive τ αm values mainly govern the sign and magnitude of τ f , and the intense rattling effect of Y 3+ drives τ f closer to zero. Finally, a cylindrical dielectric resonator antenna (CDRA) was designed and simulated using Ag 0.5 Nd 0.5 MoO 4 ceramic, demonstrating its potential for high-frequency communication applications.
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高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Yilong Zhao,Dianbing Zhou,Xiaogang Yao,Minmin Mao,Yingjie Ren,Bing Liu,Hadi Barzegar Bafrooei,Mahdi Feizpour,Peilin Qin,Huixing Lin,Shuqing Song,Kaixin Song
The demand for high-performance dielectric substrates for miniaturized radio-frequency (RF) devices and high-power electronic systems has accelerated the development of polymer–ceramic composites that simultaneously deliver high permittivity, low dielectric loss, and improved thermal conductivity. In this work, γ-aminopropyltriethoxysilane (KH550)-modified Ca 0.60 Sr 0.40 TiO 3 (CST)/polytetrafluoroethylene (PTFE) composite substrates were fabricated through a water-based tape-casting route followed by hot-press lamination, enabling uniform dispersion of CST ceramic fillers within the PTFE matrix. The incorporation of KH550 effectively enhanced interfacial compatibility between the ceramic fillers and the polymer matrix, while systematically increasing CST content improved both dielectric and thermal transport properties. At an optimal CST loading of 60 wt%, the composites exhibited a high relative permittivity ( ε r ) of 11.69 while maintaining a dielectric loss tangent (tan δ ) of 2.16 × 10 −3 at 10 GHz, together with a thermal conductivity ( λ ) of 0.714 W m −1 K −1 , a coefficient of thermal expansion (CTE) of 45.53 ppm K −1 , and an ultimate tensile strength of 15.01 MPa. Finite-element simulations reproduced the experimental trends, indicating that KH550-induced interfacial modification reduces interfacial thermal resistance and facilitates interfacial polarization within the composite system. The resulting CST/PTFE composites therefore exhibit a well-balanced combination of dielectric, thermal, and mechanical properties, highlighting their promising potential as dielectric substrates for high-frequency RF and microwave components in advanced communication technologies such as 5G systems.
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DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Kun Peng,Xinyan Yang,MD Zahidul Islam,Xiangyu Mei,Yuhao Jiang,Xiaoming Qi,Yaqin Fu
As 5G technology rapidly progresses, the demand for insulating dielectric materials with low dielectric constants, minimal dielectric loss, and enhanced thermal and mechanical properties has become increasingly critical. In order to combine the advantages of both fluoropolyimide (FPI) and polytetrafluoroethylene (PTFE), this study successfully developed an FPI/PTFE/FPI composite film with a sandwich structure that seamlessly integrated a commercial hydrophilic PTFE porous fibrous film and FPI. This structure capitalizes on the permeation effect of the FPI wet film to significantly improve interfacial interactions compared to traditional sandwich-structured composites. Consequently, the composite films have an excellent combination of properties. When the proportion of PTFE reaches 50%, the composite film remains stable across high-frequency bands (8.2 to 12.4 GHz), with an impressively low value of 1.5 at 9 GHz. The composite film also exhibits exceptional electrical breakdown strength (385.2 kV mm–1), tensile mechanical robustness (σb = 64 MPa, E = 2.1 GPa), thermal stability (Td5% = 496.1 °C, Tg = 306.2 °C), and a low coefficient of thermal expansion (51.7 ppm/K). Notably, the composite film still maintains good hydrophobic properties, with a water contact angle of 81.2° and a water absorption rate of 3.1%. This research also details an efficient coating method to fabricate flexible dielectric films, proposing a strategy for the development of advanced insulating materials suitable for high-frequency and high-speed communication applications.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2024
·
IF 8.3
Xiangyu Mei,Azim Abdullaev,Qingbiao Yang,Kun Peng,Shuaida Shi,Fujian Liu,Yinsong Si,Yaqin Fu
Polyimide (PI) has been extensively used in 5G microelectronics however the relatively high dielectric constant (∼3.5) and moisture adsorption have greatly limit its practical applications in high-frequency region. Here hydrophobic PI/SiO 2 composite films with low dielectric constant and excellent thermal stability were synthesized by dispersing methyl modified hollow silica nanospheres (MHS) into polyamic acid solution prior to imidization treatment. Comparing with unmodified hollow silica nanospheres (HS), the MHS obtained through methyl modification can disperse uniformly in the PI matrix. Thus, the relaxation and orientation polarization of the PI chains as well as their electron migration are suppressed, resulting in a significant decrease in dielectric constant. The PI/MHS-10% film exhibits a stable low dielectric constant (1.9–2.3) in the high-frequency range (8.2 GHz–12.4 GHz), meanwhile maintains a high breakdown voltage (192 kV/mm), mechanical properties (64 MPa) and an excellent thermal stability ( T d5% = 546.5 °C; T max = 589.0 °C). Moreover. PI/MHS demonstrates much lower linear expansion coefficient of 25.0 ppm/K that better matches the substrate. The surface contact angle of PI/MHS increases from 73° to 110° and the water absorption rate decreases from 3.1% to 1.6%, effectively avoiding the moisture adsorption. This work provides a simple method to prepare high-performance composite films for 5G practical applications.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Qun Diao,Yong Zeng,Jimin Chen
With the rapid advancement of 5G communication technology, higher communication frequencies have pushed the development of the Luneburg lens (LL) towards greater integration and miniaturization. In this paper, a novel Zn 2 SiO 4 -TiO 2 (ZST) ceramic Flat Luneburg Lens (FLL) for the K-band is designed and successfully fabricated using vat-photopolymerization (VPP) 3D printing technology. By optimizing the rheological properties of the slurry alongside the photopolymerization and thermal treatment processes, the resulting ZST ceramic exhibits excellent microwave dielectric properties after sintering at 1250 °C: a dielectric constant ( εᵣ ) of 9.6933, a quality factor ( Q×f) reaching 85294 GHz, a frequency temperature coefficient ( τ f ) close to zero (-0.78 ppm/°C), and an extremely low dielectric loss (1.29×10 -4 ). Building upon this high-performance ZST ceramic, a miniaturized FLL with a diameter of 30 mm and a thickness of 4 mm was successfully fabricated via metamaterial structural design. The measured results indicate that the FLL achieved a maximum gain enhancement of 5.5 dBi. This work offers useful insights into the 3D printing manufacturing of high-performance microwave dielectric ceramics and their application in miniaturized and integrated radio frequency devices.
研究领域:
材料科学
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通信工程
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电子器件
·
增材制造
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产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Jian Li,Xiaohan Zhang,Jia Liu,Qingxuan Zhou,Haitao Wu,Yuanyuan Zhou,Yang Wang,Wei Sun,Yanxiang Jiang,Yongning Han,Zhuoqun Han,Zhicheng Zhao,Futian Liu,Walther Glaubitt,Yongcui Zhang,Yingying Wang,Ling Li
(1- x )MgAl 2 O 4 - x MgTa 2 O 6 composite ceramics based on the MgO-Al 2 O 3 -Ta 2 O 5 pseudoternary phase diagram were prepared by the solid-state reaction. MgAl 2 O 4 and MgTa 2 O 6 could coexist due to their different crystal structures. MgAl 2 O 4 inhibited the rapid growth of MgTa 2 O 6 grains, and dense microstructures ( ρ > 95%) with a uniform grain size distribution was obtained, with an optimal densification temperature of 1550 - 1575 °C. The temperature coefficient of resonant frequency ( τ f ) and quality factor ( Q × f ) were optimized by introducing MgTa 2 O 6 phases with low dielectric loss and positive τ f . In addition, the partial solid solutions of Al 3+ into Ta 5+ sites resulted in loosening bonds within [Al/TaO 6 ] octahedra and abnormally large polarizabilities, which was confirmed by the decrease in V Ta-O and the redshift of A 1 g (Ta-O) mode. Consequently, the relative permittivity ( ε r ) and τ f values o f MgAl 2 O 4 -MgTa 2 O 6 composite ceramics were further enhanced, exceeding the predicted ones. The 0.6MgAl 2 O 4 -0.4MgTa 2 O 6 composition sintered at 1550 °C achieved excellent performance, with a near-zero τ f value of 3.3 ± 1.7 ppm/°C, a low ε r of 16.4 ± 0.3 and an ultra-high Q × f of 179,000 ± 6700 GHz @ 8.94 ± 0.04 GHz. These findings hold promising applications in the field of 5 G/6 G high-frequency communication.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Yang Yao,Yuanyuan Wang,Hadi Barzegar Bafrooei,Minmin Mao,Bing Liu,Zhilun Lu,Huixing Lin,Matjaz Spreitzer,Dawei Wang,Xinghua Zheng,Kaixin Song
In this work, phase-pure Mg1.8(Ni1–xCox)0.2Al4Si5O18 (0 ≤ x ≤ 1) ceramics were synthesized by a high-temperature solid-state method. On the basis of Rietveld refinement data of X-ray powder diffraction and Phillips–Vechten–Levine theory, the atomic ionicity, lattice energy, and bond energy of the compound were calculated to explore their influence on the microwave dielectric properties of ceramics. The Mg1.8Ni0.1Co0.1Al4Si5O18 (x = 0.5) ceramic exhibited the best microwave dielectric properties: εr = 4.44, Qf = 73 539 GHz@13 GHz, and τf = −23.9 ppm/°C. (Ni1–xCox)2+ complex ionic doping, compared with only Ni2+ or Co2+, is beneficial for improving the symmetry of [Si4Al2O18] hexagonal rings and reducing distortion. Subsequently, 8 wt % TiO2 was added to Mg1.8Ni0.1Co0.1Al4Si5O18, resulting in a near-zero τf and high Qf values for the composite ceramic, with εr = 5.22, Qf = 58 449 GHz@13 GHz, and τf = −2.06 ppm/°C. Finally, a 5G millimeter-wave antenna with a central operating frequency of 25.52 GHz was designed and fabricated using the Mg1.8Ni0.1Co0.1Al4Si5O18-8 wt % TiO2 ceramics. Operating in the 24.7–26.0 GHz range, it demonstrated favorable radiation characteristics with a simulated efficiency of 85.2% and a gain of 4.58 dBi. The antenna’s performance confirms the high potential of the cordierite composite for application in 5G communication systems.
研究领域:
材料科学
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微波工程
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陶瓷与复合材料
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5G通信技术
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天线设计
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DOI
高影响因子
危险品化学品经营许可证（带存储）