CERAMICS INTERNATIONAL
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2024
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IF 5.1
Guo Tian,Zhicong Chen,Linzhao Ma,Qianbiao Du,Longxiang Jiang,Hongzhi Xiao,Hao Li
Li 5 Mg 4 NbTiO 11 - x wt% LiF microwave dielectric ceramics were successfully developed using the solid state way. The phase structure, microstructure, Raman vibration, and microwave dielectric properties of LiF doped Li 5 Mg 4 NbTiO 11 ceramics were studied. The researches show that LiF doping can effectively decrease the sintering temperature of Li 5 Mg 4 NbTiO 11 ceramic. At x = 6, the ceramic sintered at 860 °C show the best performance ( ε r = 15.56, Q × f = 89,713 GHz, and τ f = −40.48 ppm/°C) and is chemically compatible with Ag electrodes. In addition, a dual-frequency dielectric resonant antenna based on 6 wt% LiF-doped ceramics was designed, which has high gain (2.94 and 6.90 dBi) and efficiency (75.5 and 95.6 %) around the resonant frequency (2.4 and 6 GHz). The comprehensive results show that this material is not only a promising LTCC material, but also a viable candidate material for 5/6G applications.
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2021
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IF 5.302
Bing Liu,Ke Sha,Ying Qiang Jia,Yu Hui Huang,Cheng Chao Hu,Lei Li,Da Wei Wang,Di Zhou,Kai Xin Song
Cold sintering is adopted to pre-densify LiF ceramics, where the relative density increases significantly from 72.1 % at 125 MPa to 88.9 % at 500 MPa. The following post-annealings at 800 °C lead to further optimizations of densification, and near-full densifications with relative densities of 95.6 % and 97.6 % are achieved at 375 and 500 MPa, respectively. Qf value increased with increasing uniaxial pressure until it reaches the maximum value of 134,050 GHz at 375 MPa, which is 1.82 times higher than that via conventional sintering (73,800 GHz). ε r and τ f are mainly determined by the relative density, and the optimum microwave dielectric properties are obtained as follows: ε r = 8.45, Qf = 134,050 GHz, τ f =–135 ppm/°C. A microstrip patch antenna is designed and fabricated using the LiF ceramic as the substrate, which gives an S11 of –20.3 dB, a simulated high efficiency of 90.5 %, and a gain of 4.25 dB at the resonant frequency of 6.81 GHz.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2023
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IF 5.7
Juan Liu,Bing Liu,Cheng Chao Hu,Qing Wei Zhou,Kai Xin Song
(1– x )BaV 2 O 6 - x LiF ( x = 0.025, 0.05, 0.10, 0.15) ceramics with an ultra-low sintering temperature of 475 °C were synthesized using the standard solid-state reaction method. The ceramics demonstrated a remarkable enhancement in the quality factor ( Qf ), reaching a maximum value of 16,800 GHz at x = 0.10, which is 5.6 times higher than that of pure BaV 2 O 6 ceramics obtained in this work. A near-zero temperature coefficient of resonant frequency ( τ f = 1.44 ppm/°C) was simultaneously achieved, together with a dielectric constant ε r of 11.54. Additionally, the chemical compatibility between the present ceramics and the Al electrode was confirmed. Moreover, a millimeter-wave antenna with an excellent S 11 value of −50.3 dB, and a large bandwidth of 3.44 GHz was fabricated using the 0.9BaV 2 O 6 -0.1LiF ceramic as the dielectric resonator . These results highlight the potential application prospects of (1– x )BaV 2 O 6 - x LiF ceramics in the ultra-low temperature co-fired ceramic technology and 5 G millimeter-wave antennas.
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
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2020
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IF 4.495
Bing Liu,Lei Li,Kai Xin Song,Min Min Mao,Zhilun Lu,Ge Wang,Linhao Li,Dawei Wang,Di Zhou,Antonio Feteira,Ian M. Reaney
LiF is a low-firing fluoride with excellent microwave dielectric properties , however densification of LiF ceramics is challenging owing to their low surface free energy. In this study, a cold sintering process (150 °C, 250 MPa, 60 min) was employed to pre-densify LiF ceramics to 78 % relative density. Post-annealing treatments between 650 °C and 800 °C led to significant grain growth which was accompanied by an increase in relative density to 92 %. The microwave quality factor ( Qf ) increased with increasing annealing temperature to a maximum of 110,800 GHz at 800 °C, 1.5 times higher than the value obtained via conventional sintering (78,800 GHz), with relative permittivity ε r = 8.2 and temperature coefficient of resonant frequency, τ f =–135 ppm/°C. Such high values of Qf and its compatibility with Ag electrode suggest that cold sintered LiF has great potential as a component or additive in low temperature co-fired ceramic formulations.
研究领域:
材料科学
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陶瓷工程
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微波工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2024
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IF 5.8
Mo Wei,Meng Fei Zhou,Bing Liu,Cheng Chao Hu,Yu Hua Cheng,Kai Xin Song
In this work, MgF 2 – x wt%LiF ( x = 0.5, 1.0, 2.5, 4.0, 5.0) ceramics have been prepared through the standard solid-state reaction method. X-ray diffraction patterns and scanning electron micrographs revealed the successful preparation of dense MgF 2 –LiF composite ceramics at an exceptionally low sintering temperature range of 525–600°C. The optimal microwave dielectric properties ( ε r = 5.09 ± 0.03, Qf = 100,733 ± 1646 GHz, τ f = −67.4 ± 3.3 ppm/°C) were achieved in MgF 2 –0.5 wt%LiF ceramics after sintering at 550 °C for 3 h. The present ceramics exhibited an outstanding combination of low- ε r , high Qf , and an ultra-low sintering temperature, surpassing the performance of most low-temperature-fired dielectric materials. Moreover, the theoretical Qf value, extrapolated from the fitting of infrared reflectivity spectra, was calculated to be 326,583 GHz, indicating significant potential for further Qf improvement. Additionally, the chemical compatibility with Al electrodes was confirmed, suggesting promising potential for ultra-low temperature co-fired ceramic (ULTCC) applications.
研究领域:
材料科学
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陶瓷
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介电材料
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微波工程
✓ 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）