JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Xingjie Su,Hongzhi Xiao,Linzhao Ma,Qianbiao Du,Guo Tian,Hao Li
With the advancement of modern microwave technology, there is an increasing demand for high-performance dielectric materials. To meet this requirement, a novel ceramic LiMg 8 AlO 10 was synthesized via a conventional solid-state method. XRD and Rietveld refinement results confirmed that LiMg 8 AlO 10 ceramics possessed a rock salt structure. The dielectric temperature spectrum analysis indicated that LiMg 8 AlO 10 ceramics exhibited stable dielectric behavior across a broad frequency range. The P-V-L theory was utilized to calculate both the bond energy and lattice energy of LiMg 8 AlO 10 ceramics. The results revealed that the Mg−O bond exerted the greatest impact on ε r with a contribution of 51.61 %. The LiMg 8 AlO 10 ceramics sintered at 1480°C exhibited excellent microwave dielectric properties: ε r = 9.97, Q×f = 123,711 GHz and τ f = −26.4 ppm/°C. Furthermore, a novel dielectric resonator antenna was designed based on the LiMg 8 AlO 10 ceramics, which has achieved outstanding performance.
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
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Chao Du,Di Zhou,Shu-Zhao Hao,He-Tuo Chen,Jian Zhang,Shi-Kuan Sun,Tao Zhou,Ming-Zhao Dang,Shao-Fei Wang,Hai-Wen Liu,Long Li,Zhuo Xu
Transparent material has been widely used in product design and has seen a large increase in its use. In this paper, a kind of aesthetically decorative 5 GHz Wi-Fi dielectric resonator antenna (DRA) of aluminum oxynitride (AlON) transparent ceramic has been designed. High-quality-factor AlON transparent dielectric ceramics were fabricated by presintering at 1780 °C and further cold isostatic pressing (CIP) under a 200 MPa argon atmosphere. For a 9.0 mm thick specimen, the in-line light transmittance reached 83%. Optimum dielectric constant (εr = 9.32), quality factor (Qf = 47 960) and temperature coefficient (TCF = −51.7 ppm/°C) was achieved in the AlON transparent ceramic by cold isostatic pressing. As a result, the proposed aesthetically decorative DRA can achieve an impedance bandwidth of 32% (4.48–6.19 GHz), a high radiation efficiency of 85%, and a low cross-polarization discrimination (XPD) of −30 dB. To achieve a broad bandwidth, the proposed antenna was excited in its dominant TE111x mode and higher-order TE113x mode. The proposed antenna is thus an excellent candidate for an indoor decoration Wi-Fi antenna.
研究领域:
材料科学
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无线通信
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陶瓷工程
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS LETTERS
·
2024
·Vol. 124
·期 9
·
IF 3.5
Zhou Pengfei,Zhang Pengcheng
The Li 2 Mg 3 Ti 1 − x Al 4 x /3 O 6 (0 ≤ x ≤ 0.1) ceramics are synthesized using the solid phase method, showing excellent microwave dielectric properties with ε r = 14.05, Q × f = 144 500 GHz, and τ f = −43 ppm/°C at x = 0.04. Rietveld refinements, based on the XRD data, reveal that the Li 2 Mg 3 Ti 1 − x Al 4 x /3 O 6 ceramics crystallize in the rock salt structure with Fm-3m space group. The relationship between the crystal structure and intrinsic microwave dielectric properties is studied in detail. The variation in the dielectric constant is related to ionic polarization and relative density. The quality factor (Q × f) demonstrates a strong correlation with lattice energy, relative density, and concentration of Ti 3+ . The variation of τ f is influenced by the bond thermal expansion coefficient and bond valence. The dielectric resonant antenna, manufactured from Li 2 Mg 3 Ti 0.96 Al 0.0533 O 6 -0.09TiO 2 ceramic with near-zero τ f , shows a bandwidth of 230 MHz at 7.40 GHz and a high radiant efficiency, which indicates that high-quality factor Li 2 Mg 3 Ti 0.96 Al 0.0533 O 6 ceramic has significant potential in relevant fields such as 5G and smart driving.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 30
·63013-63021
·
IF 5.6
Ning Zhang,Junqi Chen,Ning Guan,Huaicheng Xiang,Ying Tang,Yuandong Qin,Liang Fang
Two novel ceramics, Li 2 Mg 2 Ga 2 Ti 3 O 12 (LMGT) and Li 2 Zn 2 Ga 2 Ti 3 O 12 (LZGT), featuring a spinel structure, were synthesized utilizing the solid-state method. Comprehensive characterization confirms that LZGT ( P 4 3 32) forms a B-site 1:3 ordered spinel, while LMGT ( Fd -3 m ) adopts a disordered spinel structure. The ceramics exhibit outstanding microwave dielectric properties, characterized by low ε r of 14.92 and 19.11, high Q×f of 120,000 and 93,800 GHz, and negative τ f of −40.21 and −32.83 ppm/°C for LMGT and LZGT, respectively. The observed ε r values significantly exceed theoretical values due to underestimated Ti 4+ polarizability along with the rattling effect of Ti 4+ and Ga 3+ . Q×f values correlate with packing fraction, lattice energy, and electrical properties. The negative τ f values stem from dominant positive τ ε and τ αm contributions. Utilizing LMGT with ultra-low loss, a dielectric resonator antenna was designed, achieving a radiation efficiency of 93.01 % and a gain of 6.12 dBi at 6.60 GHz, highlighting significant potential for C-band communication satellite applications.
研究领域:
材料科学
·
无机非金属材料
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电子功能材料
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微波技术
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天线工程
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固态化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jie Li,Ziyi Zhang,Hongji Zou,Ying Tang,Weiping Gong,Liang Fang
Dense ALaGa 3 O 7 (A = Ba, Sr, Ca) ceramics with tetragonal melilite structure were prepared by the solid-phase method. The optimal microwave dielectric properties were obtained with ε r = 11.1 ± 0.1, 11.3 ± 0.1, 13.3 ± 0.1; Q × f = 49,400 ± 300, 31,100 ± 300, 17,100 ± 300 GHz; and τ f = −41.5 ± 1.0, −36.6 ± 1.0, −28.8 ± 1.0 ppm/°C for BaLaGa 3 O 7 , SrLaGa 3 O 7 , and CaLaGa 3 O 7 , respectively. The increased ε r and τ f while reduced Q × f in the order of BaLaGa 3 O 7 , SrLaGa 3 O 7 , and CaLaGa 3 O 7 were mainly due to the enhanced rattling effect of A-site, which resulted in large positive discrepancy Δ ε r between ε r ( Corr ) and ε r (C-M) increasing from +31.8 % to +74.7 %. The vibration modes, chemical bond characteristic and intrinsic dielectric properties were analysed by Raman, P-V-L theory, and far-infrared reflectance spectroscopy. Additionally, a dielectric resonator antenna based on BaLaGa 3 O 7 ceramic was designed with a bandwidth of 270 MHz at 6.8–7.1 GHz and a gain of 5.6 dBi at 6.9 GHz, indicating the potential candidate for dielectric resonator antennas.
研究领域:
材料科学
·
电子功能材料
·
微波技术
·
无机非金属材料
·
介电材料
✓ 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）