JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Sijie Wang,Weishuang Fang,Daofu Wu,Kuiyi Meng,Ying Tang,Junfeng Yang,Mingjian Ding,Huixing Lin,Liang Fang
K20 microwave dielectric ceramics SrLnAlO 4 (Ln = Eu, Gd, and Ho) were prepared at 1440–1520 °C. SrEuAlO 4 and SrGdAlO 4 crystallized into tetragonal K 2 NiF 4 -type structures. While SrHoAlO 4 was a mixture (SrHo 2 Al 2 O 7 , Ho 2 O 3 , and Sr 3 HoAl 2 O 7.5 ) due to the too-small radius of Ho 3+ to bond in [HoO 9 ] dodecahedron . SrEuAlO 4 and SrGdAlO 4 exhibited near-zero τ f values of +1.7 and +4.3 ppm/°C and low ε r (19.37 and 19.14) along with contrasting Q × f values (70,030 and 5560 GHz). Compared with the modified molecular polarizability ( α Corr ) based on the bond valence deviation, the α obs values of SrEuAlO 4 and SrGdAlO 4 are much higher, indicating that their dielectric polarizabilities were underestimated, and this phenomenon was mainly influenced by rattling cations, which also causes their τ f with near-zero values. Due to the magnetic subsystem adversely affecting microwave dielectric losses , the worsened Q × f value of SrGdAlO 4 compared to that of SrEuAlO 4 is due to the high magnetic moment of Gd 3+ (7.94 μ B ).
研究领域:
材料科学
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电子工程
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Bing Liu,Ke Sha,Meng Fei Zhou,Kai Xin Song,Yu Hui Huang,Cheng Chao Hu
Two novel low- ε r gallates MGa 2 O 4 (M = Ca, Sr) have been synthesized via a standard solid-state reaction method. According to the X-ray diffraction results, CaGa 2 O 4 crystallizes in space group Pna2 1 with an orthorhombic symmetry, while SrGa 2 O 4 belongs to the monoclinic P2 1 / c system. Both ceramics show ever-improving microstructures with the increasing sintering temperature . The optimal microwave dielectric properties ( ε r = 9.2, Qf = 66,000 GHz, τ f =–85 ppm/°C for SrGa 2 O 4 and ε r = 10.6, Qf = 15,400 GHz, τ f =–58 ppm/°C for CaGa 2 O 4 ) are obtained when sintered at 1275 °C. A patch antenna is fabricated using SrGa 2 O 4 ceramics as the substrate, which realizes a return loss of –19.94 dB and total efficiency of –1.38 dB (72.8 % in power ratio) at 4.84 GHz. The exceptional performances indicate that SrGa 2 O 4 ceramics are promising candidates for antenna applications at the Sub-6 GHz band.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Weishuang Fang,Kai Cheng,Huicheng Xiang,Ying Tang,Yifan Zhai,Congxue Su,Liang Fang
It has become a focus to develop low-permittivity microwave dielectric materials to meet the needs of high-speed transmission in telecommunication devices. Here, we report two Ge-based microwave dielectric ceramics prepared using the conventional solid-state method, MgGeO 3 and ZnGeO 3 , with low permittivity of 6.8 and 6.6, the high-quality factor of 65,200 GHz and 25,200 GHz, and negative temperature coefficient of −45 ppm/°C and −35 ppm/°C. Orthorhombic ilmenite structure of MgGeO 3 can be obtained in the range of 1160–1240 °C. However, the single-phase ZnGeO 3 is not available in air, and the ceramics sintered at 1040–1120 °C contain two phases of Zn 2 GeO 4 and GeO 2 .
研究领域:
材料科学
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电子工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jia Wang,Le Xin,Mingwei Zhang,Xin Geng,Ruihang Li,Pengchao Shao,Panpan Lyu,Hui Peng,Luchao Ren,Cuncheng Li
Microwave dielectric ceramics of Sr 2 SiO 4 incorporated with different contents of Ba 0.5 Sr 0.5 TiO 3 were prepared using a solid-phase reaction. Their phase composition, micro-structure evolution and dielectric properties were investigated systematically. The results reveal that increasing the x content to 50 wt% leads to greater lattice distortion and defects formation caused by ion substitution within the composite ceramics, resulting in an increase in the dielectric permittivity while a degradation in the Q value. As the x content continues to increase, the enhanced connectivity and ferroelectric properties caused by Ba 0.5 Sr 0.5 TiO 3 within the composite ceramics trigger a sharp increase in the dielectric permittivity. However, the deterioration in Q value is suppressed by the composite effect, and its value gradually increases. At the same time, structural transformations occur within the composites, possessing relaxation properties. Optimal microwave dielectric performance is achieved at x = 25 wt%, indicating balanced properties with ε r = 26.41, Q = 1578 (4.658 GHz), and tanδ = 0.001581.
研究领域:
材料科学
·
无机非金属材料
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DOI
高影响因子
Crystals
·
2025
·Vol. 15
·期 7
·623
·
IF 2.4
Xuekai Lan,Bairui Chen,Huatao Tang,Changzhi Yin,Bin Tian,Wen Lei
Microwave dielectric ceramics are indispensable in modern communication technologies, playing a pivotal role in components such as filters, oscillators, and antennas. Among these materials, ZnAl2O4ceramics have garnered attention for their excellent quality factor (Q × f) and low dielectric constant (εr). However, their high sintering temperature (~1650 °C) limits practical applications. This study investigates ZnAl2-x(Zn0.5Si0.5)xO4(ZAZS) (x= 0.1–0.9) ceramics, where [Zn0.5Si0.5]3+substitutes Al3+, to reduce sintering temperature while maintaining high-performance microwave dielectric properties. ZAZS ceramics were synthesized via the solid-state reaction method and characterized for their structural, morphological, and dielectric properties. X-ray diffraction analysis confirmed the formation of a single-phase solid solution up tox= 0.8, with minor secondary phases appearing atx= 0.9. The substitution increased lattice parameters and enhanced material densification, as observed through SEM and relative density calculations. Microwave dielectric measurements showed that ZAZS ceramics achieved a maximumQ × fof 20,200 GHz and aτfvalue reduced to −62 ppm/°C atx= 0.8, whileεrdecreased from 7.90 to 6.98. Bond-valence calculations reveal that the reduction of the average Al/Zn/Si–O bond valence weakens octahedral rigidity, systematically tuningτftoward zero. These results demonstrate that ZAZS ceramics, with a reduced sintering temperature of 1400 °C, exhibit excellent potential for application in low-loss microwave devices.
研究领域:
材料科学
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电子工程
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无机非金属材料
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 17
·14879-14885
·
IF 2.22
Niu Shuting,Jiang Juan,Wang Jinzhao,Gan Lin,Zhang Tianjin
0.67CaTiO 3 –0.33LaAlO 3 (CTLA) microwave dielectric ceramic materials with the additives of H 3 BO 3 , Li 2 CO 3 or H 3 BO 3 –Li 2 CO 3 were prepared by a conventional solid-state reaction method. The effects of the sintering additives on the densification behavior, phase compositions, microstructures, and microwave dielectric properties of the CTLA ceramic samples were investigated. It was found that the binary additive of H 3 BO 3 –Li 2 CO 3 effectively promoted the densification and lowered the sintering temperature of the CTLA ceramic samples without a significant decrease in their Q × f values. For example, with an addition of 0.2 wt% H 3 BO 3 –0.1 wt% Li 2 CO 3 , the optimal microwave dielectric properties of ε r = 45.5, Q × f = 31,771 GHz and a near-zero τ f of 2.43 ppm/℃ were obtained in the CTLA ceramic sample sintered at only 1175 ℃, which is significantly lower (~ 225 ℃) compared to the sintering temperatures of conventionally sintered CTLA ceramics.
研究领域:
材料科学
·
电子材料
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Huang Ming,Zhang Jinxian,Tang Yu,Mao Haijun,Liu Zhuofeng,Li Wei,Wang Fenglin,Zhang Weijun,Chen Xingyu
A novel MnTiNb 2 O 8 -based microwave dielectric ceramic was synthesized by solid-state route and its microwave dielectric properties were investigated. The effects of excess Mn 2+ on the microstructure and microwave dielectric properties of Mn x TiNb 2 O 8 ( x = 1.00–1.20) were investigated. The X-ray diffraction and scanning electron microscopy results showed that MnTiNb 2 O 8 was the dominant crystalline phase in all samples, but TiO 2 , as a second phase, was consistently present. The complex impedance spectroscopy and X-ray photoelectron spectroscopy analysis suggested that the addition of a small amount of Mn could inhibit the formation of oxygen vacancies and hinder the reduction of Ti 4+ . The study found that by adding a small amount of Mn, the quality factor ( Q × f ) of ceramics can be significantly improved without affecting the dielectric constant ( ε r ), thereby greatly optimizing the dielectric properties of ceramics. Subsequently, the temperature coefficient of resonant frequency ( τ f ) of the ceramic was successfully adjusted to near zero by adding a small amount of Zr 4+ instead of Ti 4+ . Among all Mn x Ti 1- y Zr y Nb 2 O 8 ( x = 1.00–1.20, 0 ≤ y ≤ 0.28) ceramics, samples with x = 1.05 and y = 0.1 sintered at 1200 °C showed the best microwave dielectric properties: ε r = 32.9, Q × f = 11,427 GHz, and τ f = 0 ppm/°C.
研究领域:
材料科学
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电子工程
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高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Xiaohui Wu,Xixi Wang,Yulan Jing,Yuanxun Li,Hua Su
With the emergence of 5G–6G communication technology, the miniaturization and integration of electronic components are crucial. Ba 3 Ti 4 Nb 4 O 21 (BTN) ceramics with hexagonal structures have attracted special attention due to their high dielectric constant, which shows greater application potential in communication base stations and dielectric resonators. However, its high sintering temperature and low-quality factors also greatly limit the application field. In this paper, boric acid (H 3 BO 3 ) as a dopant, was used to investigate the influence on the structure, microstructure, Raman spectrum, and microwave properties for Ba 2.92 Cu 0.08 (Zn 1/3 Nb 2/3 ) 2 Ti 2 Nb 4 O 21 (BCZTN)- x HB (0.25≤ x ≤1.25 wt%) ceramics. The results reflected that H 3 BO 3 was an effective additive, which could promote ceramic densification, accelerate grain growth and uniform distribution, and enhance its microwave performance. Among them, high densification was 93.92 ± 0.35%, and the Q × f value ∼16981 ± 340 GHz at x = 0.75, was more than 2∼3 times higher than other BTN-based ceramics. Superior microwave dielectric properties were achieved for 0.75 wt% H 3 BO 3 -doped BCZTN ceramic sintered at 900°C: ε r ∼42.35 ± 0.48, Q× f ∼16981 ± 340 GHz, and τ f ∼40.02 ± 1.43 ppm/°C. More encouragingly, BCZTN-0.75HB ceramic did not chemically react with Ag, which suggested that it had the potential to be a candidate material for low-temperature co-fired ceramics base station communication devices.
研究领域:
材料科学
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电子工程
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高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 106
·期 7
·4284-4293
·
IF 3.9
Changzhi Yin,Kang Du,Xiaoqiang Song,Ying Xiong,Jiaqing Yang,Mingfei Cheng,Yiyang Cai,Wei Luo,Huanhuan Guo,Wenzhong Lu,Chunchun Li,Wen Lei
The dielectric properties of a Ga-based melilite type ceramic Sr 2 Ga 2 SiO 7 via theoretical prediction based on far-infrared spectroscopy and experimental measurement by the Hakki–Coleman method were studied in this work. Dense and single-phase ceramics were fabricated via solid-state reaction at 1330°C and exhibited comprehensive microwave dielectric properties ( ε r ∼ 7.6, Q × f ∼ 23 600 GHz, and τ f ∼ −35.2 ppm/°C) at 14.3 GHz. Chemical modifications were proposed to adjust the thermal stability and reduce the densification temperature. By adding 10 mol% CaTiO 3 , the negative τ f can be compensated to a near-zero value of −3.8 ppm/°C. The densification temperature was reduced to 940°C by adding 3 wt.% LiF. A patch antenna was designed using Sr 2 Ga 2 SiO 7 ceramic with a high radiation efficiency of 99.1% and a gain of 2.788 dBi at the center frequency of 4.371 GHz. All results indicate that the Sr 2 Ga 2 SiO 7 ceramic has promising application potential for 5G wireless communication technology.
研究领域:
材料科学
·
电子工程
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Linzhao Ma,Guo Tian,Hongzhi Xiao,Longxiang Jiang,Qianbiao Du,Hao Li,Bin Yang
This research used the co-substitution strategy to prepare novel spinel-type Mg 3 Ga 2 SnO 8 ceramics sintered at 1430–1510 °C. Rietveld refinement and SEM showed that the Mg 3 Ga 2 SnO 8 ceramic had a cubic spinel structure with a space group of F d 3 ¯ m ( 227 ) , where Mg1 and Mg2/Ga1/Sn1 occupy the tetrahedron and octahedron, respectively. The relative density exhibited a considerable influence on the ε r of Mg 3 Ga 2 SnO 8 ceramics. In addition, the Q × f of the ceramics was closely related to the packing fraction and FWHM. Infrared reflection spectra were used to investigate the intrinsic dielectric characteristics of the ceramics. The P−V−L theory indicated that Sn−O and Ga−O bonds contribute substantially to the ε r and Q × f , respectively. The Mg 3 Ga 2 SnO 8 ceramics had the optimum microwave dielectric properties of ε r = 9.3, Q × f = 189,052 GHz, and τ f = −34.25 ppm/°C when sintered at 1470 °C. Therefore, Mg 3 Ga 2 SnO 8 ceramics exhibit a wide range of possible applications in the field of microwave media.
研究领域:
材料科学
·
电子材料
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Kui Liu,Dainan Zhang,Yuran Yang,Qisheng Yin,Yida Lei,Cheng Liu,Jie Li,Lichuan Jin,Yulong Liao,Huaiwu Zhang
Herein, the sintering behavior, structural evolution, microstructure, and dielectric properties of Li 2+ x MgTiO 4 F x (0 ≤ x ≤ 5) ceramics were investigated. At x ≤ 0.75, Li 2+ x MgTiO 4 F x ceramics formed a continuous solid solution with a cubic rock salt structure. Subsequently, a composite ceramic of Li 2+ x MgTiO 4 F x and LiF was formed. It was found that the maximum mass percentage of LiF required to fully form a solid solution was between 11% and 13%. The Li 2.75 MgTiO 4 F 0.75 exhibited the best dielectric properties: ε r = 16.52, Q × f = 123,574 GHz, and τ f = −18.11 ppm/°C. The substitution of F - for O 2- resulted in a lower sintering temperature of 875 °C, which slightly suppressed the volatilization of Li, and thus optimized the dielectric properties. The decrease in lattice vibration damping behavior and the increase in electron cloud density resulted in lower dielectric losses. The reduction in molecular polarization rate led to a reduction in ε r , and the increase in bond energy optimized τ f . Good chemical compatibility with Ag electrode was demonstrated, indicating that Li 2+ x MgTiO 4 F x ceramics have unlimited potential for LTCC applications.
研究领域:
材料科学
·
电子工程
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Zitao Shi,Xiao Zhang,Xiaodong Feng,Zeyu Zheng,Feng Si,Bin Tang
The development of high-frequency communication technology urgently requires new types of microwave dielectric ceramics with excellent performance. New melilite-structured SrSmGa3O7 ceramics were prepared by using the conventional solid-state method. The impedance analysis demonstrates that SrSmGa3O7 ceramics have good insulation characteristics, with the conducting activation energies of 0.51 and 1.01 eV for the grain and grain boundary, respectively. The bond valence theory suggests that the stretched Sm–O and Ga–O bonds have a major influence on εr, leading to a higher measured value than the theoretical one (7.6). The calculation by P–V–L chemical bond theory shows that the Sr/Sm–O bond significantly affects the bond ionicity (fi), and the Ga–O bonds have a crucial influence on the lattice energy (Ub) and bond energy (Eb). This result provides guidance for SrSmGa3O7 ceramic modification to enhance its performance. The 1425 °C sintered SrSmGa3O7 ceramic exhibited the optimal microwave dielectric properties (εr = 12.1 ± 0.1, Q × f = 27,740 ± 613 GHz (at 11.4 GHz), and τf = −37.5 ± 0.4 ppm/°C), indicating that the SrSmGa3O7 ceramics are a favorable dielectric material for high-frequency applications.
研究领域:
材料科学
·
无机非金属材料
·
微波电子学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）