JOURNAL OF ALLOYS AND COMPOUNDS
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2023
·
IF 6.2
Yun Zhang,Xi Jiang,Xinrui Guo,Shihua Ding,Tianxiu Song
The Mg 1- x Li x ZrTa 2 O 8- x /2 ( x = 0–0.07) ceramics were fabricated to investigate the effects of Li + heterovalent substitution for Mg 2+ . The site occupancy and existence of the Li + were examined based on Vienna Ab-initio Simulation Package (VASP) and X-ray photoelectron spectroscopy (XPS), respectively. Single phase solid solution with wolframite structure was identified in the whole region. Li + substitution reduced the densification temperature from 1475 °C to 1400 °C. Notably, the Q × f exhibited an obvious increase by up to 74 % from 41,844 GHz at x = 0–72,782 GHz at x = 0.05. The Q × f for x < 0.01 was largely dependent on the intrinsic loss originating from packing fraction, while as 0.01 ≤ x ≤ 0.05, it was dominated by extrinsic factors, especially the oxygen vacancy concentration. The corresponding dielectric constant ε r decreased in term of ionic polarizability. The variations of resonant frequency temperature coefficient τ f were explained from the views of [TaO 6 ] oxygen octahedral distortion and bond energy. A near-zero τ f was obtained for x = 0.05 composition, accompanied by ε r = 11.97, Q×f = 72,782 GH at 1450 °C. Li substitution was effective and inexpensive for MgZrTa 2 O 8 ceramic to realize dielectric properties enhancement and densification temperature optimization simultaneously.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2025
·Vol. 36
·期 25
·1-10
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IF 2.8
Yang Jing,Dan Jiaying,Zhang Yun,Ding Shihua
This study proposed a novel glass-phase sintering additive composed of ZnO, Al 2 O 3 , SiO 2 , B 2 O 3 , and Co 2 O 3 (ZASBC). Its effects on the structure and properties of Al 2 O 3 ceramics were investigated. XRD results indicated that the addition of ZASBC preserved the original hexagonal crystal system of Al 2 O 3 ceramics while reducing the optimal densification temperature to 1350 °C, achieving a bulk density of 3.972 g/cm 3 . The dielectric constant ( ε r ) reached 9.79, with its variation primarily attributed to relative density. At 1 wt% ZASBC addition, the quality factor ( Q × f ) of the sample improved to 131,272 GHz. This enhancement was driven by high packing fraction and relative density. Additionally, the temperature coefficient of resonant frequency ( τ f ) was found to correlate mainly with ε r . The Al 2 Oz 3 –1 wt% ZASBC samples sintered at 1400 °C demonstrated outstanding microwave dielectric properties.
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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微波技术
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DOI
高影响因子
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
PHYSICA SCRIPTA
·
2023
·Vol. 98
·期 9
·095923
·
IF 2.9
Sen Peng,Chen Li,Tianyi Yan,Shengxiang Huang,Leilei Qiu,Lianwen Deng
For the MCu2Nb2O8 (M=Ca, Mg, Zn or Ni) composite ceramics, it is still a difficult problem to achieve both high Q×f valule and near-zero temperature coefficient of resonant frequency (τf). In this paper, the (1-x)MgCu2Nb2O8 − xTiO2 (0 ≤ x ≤ 0.28) ceramics were fabricated by the two-step sintering (TSS) technique. Results of x-ray diffraction (XRD) and Raman spectroscopy proved that the ceramic samples were composite phases of MgNb2O6, CuO and TiO2. The chemical compositions and valences of Mg, Cu, Nb, O and Ti were investigated by x-ray photoelectron spectroscopy (XPS). Scanning electron microscopy (SEM) showed that proper TiO2 addition could promote growth of grains and increase the average grain size. Appropriate TiO2 content and enhanced densification contributed to the 0.84MgCu2Nb2O8 − 0.16TiO2 ceramics sintered at 935 °C with εr = 18.75, Q×f = 34,398 GHz (f0 = 7.8 GHz), and τf = −0.56 ppm/°C, exhibiting potential applications in Low Temperature Co-fired Ceramic (LTCC) devices.
研究领域:
材料科学
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电子材料
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陶瓷材料
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Kang Du,Changzhi Yin,Wei Zhu,Cai Zhou,Bohan Zhang,Tingting Wang,Shengxiang Wang,Wen Lei
The phase compositions and microwave dielectric properties of Sn-deficient Ca 2 Sn 2 Al 2 O 9 ceramics in this study were explored. The CaSnO 3 and SnO 2 second phases existed at Ca 2 Sn 2- x Al 2 O 9-2 x ( x = 0) ceramic. Single-phase Ca 2 Sn 2 Al 2 O 9 ceramics were obtained at 0.08 ≤ x ≤ 0.1, and the orthorhombic structure with the Pbcn space group of Ca 2 Sn 2 Al 2 O 9 was verified. For multi-phase Ca 2 Sn 2- x Al 2 O 9-2 x (0 ≤ x ≤ 0.06) ceramics, their microwave dielectric properties were mainly affected by second phase contents, and their Q × f values increased gradually with the rise in x . High Q × f (105,700 GHz at 12.99 GHz) was obtained by the Ca 2 Sn 2- x Al 2 O 9-2 x ( x = 0.08) ceramic with high intrinsic Q × f (175,000 GHz). The large deviation between measured Q × f values and fitted intrinsic Q × f values could be ascribed to the Sn 4+ vacancies of the Sn-deficient Ca 2 Sn 2 Al 2 O 9 ceramics. The Ca 2 Sn 2- x Al 2 O 9-2 x (0 ≤ x ≤ 0.1) ceramics presented large negative τ f values, and this τ f was mainly affected by τ ε . Meanwhile, the Ca 2 Sn 2- x Al 2 O 9-2 x ( x = 0.08) ceramic achieved optimal microwave dielectric properties ( ε r = 8.3, Q × f = 105,700 GHz at 12.99 GHz and τ f = −63.7 ppm/°C), indicating the good feature of this material for millimetre-wave applications.
研究领域:
材料科学
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电子材料
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2022
·
IF 6.364
Shuai Li,Chen Li,Minmin Mao,Kaixin Song,Yaseen Iqbal,Amir Khesro,Sinan S. Faouri,Zhilun Lu,Bing Liu,Shikuan Sun,Dawei Wang
In this work, Zn-Ni co-modified LiMg 0.9 Zn 0.1- x Ni x PO 4 ( x = 0–0.1) microwave dielectric ceramics were fabricated using a solid state synthesis route. Rietveld refinement of the XRD data revealed that all ceramic samples have formed a single phase with olivine structure. SEM images showed that the samples have a dense microstructure, that agrees with the measured relative density of 97.73 %. Based on the complex chemical bond theory, Raman and infrared reflectance spectra, we postulate that ε r is mainly affected by the ionic polarizability, lattice and bond energy, while P-O bond plays a decisive role in Q×f and τ f value. Optimum properties of Q×f ~ 153,500 GHz, ε r ~ 7.13 and τ f ~ −59 ppm/°C were achieved for the composition LiMg 0.9 Zn 0.06 Ni 0.04 PO 4 sintered at 875 ℃ for 2 h. This set of properties makes these ceramics an excellent candidate for LTCC , wave-guide filters and antennas for 5 G/6 G communication 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 SOLID STATE CHEMISTRY
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2025
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IF 3.5
Shengming Liu,Yun Zhang,Shihua Ding,Tianxiu Song
V cation was introduced at Nb-site in CoTiNb 2 O 8 for the purpose of tuning the defects concentration. XRD analysis indicated that no secondary phase developed over the whole composition range. The sintering temperature decreased to 1150 °C in current work, compared with pure CoTiNb 2 O 8 ceramic (∼1250 °C). V-introduction inhibited grain growth and benefited grain homogenization. The decreased molecular dielectric polarizability and blue shift of Raman A 1g mode both made lower ε r from 59.2 to 41.8. Based on the X-ray photoelectron spectroscopy (XPS), V doping decreased the oxygen vacancy concentration and tuned the Co valence state. The defects compensation by oxygen and Co vacancies significantly improved Q × f up to 38,012 GHz, accompanied with a 50% rise. The slight increase in τ f was attributed to the Nb-O bond energy reduction. The CoTi(Nb 0.97 V 0.03 ) 2 O 8 had a high ε r of 54.6 with good Q × f of about 38,012 GHz and τ f =96.47 ppm/°C. Enhanced Q × f and low sintering temperature were achieved simultaneously.
研究领域:
材料科学
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物理学
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2022
·
IF 6.364
Xinglong Liu,Zexing Wang,Xinyao She,Quanliang Jia,Jiamao Li
In this study, LiF was utilized to decrease sintering temperature , improve microstructure, enhance Q × f , and regulate τ f of Li 2 Ti 0.9 (Zn 1/3 Ta 2/3 ) 0.1 O 3 (abbreviated as LTZT) ceramics. A complete solid solution together with a phase transition from monoclinic to cubic rock salt structure occurred. The cell volume of LTZT ceramics decreased as the LiF content increased. Relatively dense and uniform microstructures were observed for the ceramics as the LiF content was not less than 2 wt%. The dielectric constant of LTZT ceramics initially increased and then decreased with the increasing LiF content. The FWHM of the Raman band at about 808 cm −1 was closely related to the Q × f value. Notably, the samples with 3 wt% LiF exhibited the highest relative density of 97.4 % and satisfactory microwave dielectric properties of ε r = 23.14 ± 0.16, Q × f = 110,090 ± 1100 GHz, and τ f = +3.25 ± 1.45 ppm/°C when sintered at 950 °C. Good chemical compatibility with silver indicated the ceramic is a promising candidate in LTCC applications.
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
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Shucheng Liu,Xiaoqing Chen,Pengcheng Zhang,Quanzhang Wen,Linzhao Ma,Hao Li
A novel low-loss La 5 Sn 4 O 15 ceramic is fabricated via traditional solid-state route. The investigation mainly focused on phase composition, dielectric characteristics and crystalline from 1300 to 1400 °C. The XRD analyses confirmed the La 5 Sn 4 O 15 ceramic is consisted of cubic and hexagonal structure. The effects of relative density on the Q × f and permittivity are also investigated. The satisfactory properties (ε r of 17.4, Q × f of 84,760 GHz and τ f of −19.08 ppm/°C) are obtained at optimum sintering condition (sintered at 1350 °C for 4 h), indicating La 5 Sn 4 O 15 ceramic is a promising ceramic for using in wireless applications region.
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
ADVANCED ENGINEERING MATERIALS
·
2024
·
IF 3.4
Lan Gao,Yun Zhang,Shihua Ding
Herein, Mg 1− x Ni x ZrTa 2 O 8 ( x = 0, 0.1, 0.3, 0.5, 0.8, 1) ceramics are synthesized using a solid-phase reaction method. Ni 2+ replacing Mg 2+ improves the drawback of high sintering temperature and poor temperature stability. The samples have a relative density above 95% at the optimal sintering temperature. The sintering temperature of Mg 1− x Ni x ZrTa 2 O 8 reduces from 1475 to 1400 °C. And single-phase Mg 1− x Ni x ZrTa 2 O 8 ceramics with monoclinic wolframite structures are analyzed. According to the Rietveld refinement results, with the doping of Ni 2+ , the transformation of unit cell volume leads to the shift of the main peak in the X-Ray diffraction pattern to a higher angle in 0 ≤ x ≤ 0.3 and a lower angle in 0.5 ≤ x ≤ 1. The ε r of Mg 1− x Ni x ZrTa 2 O 8 is comparable to MgZrTa 2 O 8 . At 1400 °C, the Q × f is increased from 10 598 GHz in the undoped sample to 43 041 GHz in Mg 0.9 Ni 0.1 ZrTa 2 O 8 ceramic. The absolute values of τ f of ceramic samples decrease with the excessive Ni 2+ . The desirable dielectric properties ( ε r = 20.79, Q × f = 43 041 GHz, τ f = −33.04 ppm °C −1 ) are obtained at 1400 °C. Ni substitution is effective for MgZrTa 2 O 8 ceramic to optimize densification temperature and retain the high Q × f value.
研究领域:
材料科学
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电子材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2022
·Vol. 51
·期 7
·3896-3902
·
IF 2.047
Cheng Jiawen,Qing Zhenjun,Wang Jin,Zhao Yun,Zhou Xin,Zou Huapeng,Li Haiyan,Li Yingxiang
In this paper, the traditional solid-phase reaction sintering process was used to synthesize Ca 1-x Mg x V 2 O 6 (x = 0.03, 0.06, 0.09, 0.12) ceramics under low-temperature conditions. The effects of partial replacement of Ca 2+ by Mg 2+ on the A-site on the crystalline type, sintering temperature, microstructure, densification, and microwave dielectric performances of Ca 1-x Mg x V 2 O 6 ceramic were studied. The only crystalline phase of CaV 2 O 6 was observed in the ceramics. The sintering densification and dielectric performances of the Ca 1-x Mg x V 2 O 6 ceramic show a trend of first increasing and then decreasing with the increase of Mg 2+ content. The addition of Mg ions can effectively increase the Q × f value of the Ca 1-x Mg x V 2 O 6 ceramics but cannot improve the τ f value. The Ca 0.91 Mg 0.09 V 2 O 6 ceramic sintered at 725°C displayed good microwave dielectric performances: ε r = 10.41, Q × f = 68524 GHz, and τ f = − 36.8 ppm/°C. The good dielectric properties of this ceramic can meet the development needs of 5G communication technologies.
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
·
2024
·
IF 5.8
Sen Peng,Lei Xiao,Yingxiang Li,Lianwen Deng,Jiahui Zhu,Zhenjun Qing,Yecheng Xi
A novel Ba 3 (ZnB 5 O 10 )PO 4 (BZBPO) phosphate ceramic was synthesised using a conventional solid-state technology. The BZBPO ceramic sintered at 850 °C demonstrated exceptional microwave dielectric properties : ε r = 5.88 ± 0.08, Q×f = 52,896 ± 1200 GHz ( f 0 = 16.5 GHz) and τ f = 0.34 ± 0.25 ppm/°C. Raman spectroscopy revealed that ε r and Q×f were negatively correlated with the Raman shift and full width at half maximum of the BZBPO ceramic, respectively. Meanwhile, Phillips–Vechten–Levine theory revealed that Q×f was highly correlated with the lattice energy ( U b ), and τ f was closely related to the bond energy ( E b ) and the thermal expansion coefficient. Among contribution ratios of individual chemical bonds, the B–O bond mainly contributed to U b , E b and ionicity, proving that the bond dominantly affected the dielectric properties of the BZBPO ceramic. Finally, the BZBPO ceramic was co-fired with silver, demonstrating its potential applicability towards low temperature co-fired ceramic 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
危险品化学品经营许可证（带存储）