CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Zhenjun Qing,An Liu,Shumin Duan,Haiyan Li,Yan Xue
Li 5 Mg 3 Ti 2 O 9 F (LMTOF) ceramic was successfully synthesized using the solid-state reaction method at a temperature of 925 °C. XRD analysis revealed the presence of a unique cubic structure, resulting in the formation of a solid solution of Li 5 Mg 3 Ti 2 O 9 F. Notably, a significant correlation was observed between the ions polarization and the ε r of the LMTOF ceramic. Furthermore, the impact of sintering temperature on the ε r and Q × f value of the ceramic was primarily evidenced by changes in the sintered density. Applying the P–V-L theory, computational results highlighted the crucial role played by the ionicity of Mg–O/F and Ti–O/F in determining the behavior of the LMTOF ceramic. Particularly, the lattice energy associated with the Ti–O/F bond exerted a predominant influence on the Q × f value, while the bond energy of Li–O/F exhibited a greater impact on the τ f . Additionally, insightful details regarding the lattice vibrations of the ceramic were obtained through Raman spectroscopy. Impressively, the ceramic sintered at 925 °C exhibited exceptional microwave dielectric performance, demonstrating an ε r of 14.8, a Q × f value of 98,500 GHz, and a τ f of −15.6 ppm/°C. These outcomes underscore the significant potential of LMTOF ceramic for advancements in the LTCC field.
研究领域:
材料科学
·
化学
✓ 已验证
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
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Jin Fang,Tao Ni,Minmin Mao,Yu Liu,Huan Liu,Lei Cao,Xueqing Yu,Bing Liu,Hadi Barzegar Bafrooei,Liang He,Yingjie Ren,Fayaz Hussain,Dawei Wang,Kaixin Song
MgSiO 3 ceramics with a low dielectric constant are highly promising for application in 5G communication due to their excellent performance and cost-effectiveness. However, the application remains constrained by phase transitions. This study aims to unlock their full potential by introducing Cu ions to mitigate phase transitions, thereby achieving stable and superior performance. Mg 1- x Cu x SiO 3 (0 ≤ x ≤ 0.25) ceramics were synthesized by solid-state method, and the effects of Cu introduction on the crystal structure, phase constitution, microstructure and microwave dielectric properties were systematically investigated. Through XRD patterns and Rietveld refinement , it was found that when x = 0, both protoenstatite (PEN) and low-temperature clinoenstatite (CEN) phases coexist due to a phase transition from PEN to CEN. As x increases, the PEN phase dominance rises while the CEN phase diminishes, indicating that the addition of Cu ions inhibits the occurrence of phase transition. At x ≥ 0.2, only the orthoenstatite (OEN) phase was observed. SEM and EDS analyses revealed the beneficial impact of Cu introduction on sintering, yet excessive amounts can lead to abnormal grain growth , local segregation, and uneven distribution of Cu elements, thereby deteriorating microwave dielectric properties . The optimal microwave dielectric performance was achieved at x = 0.05: ε r = 6.2, Qf = 93,600 GHz, τ f = −33.7 ppm/°C. A one-year long-term comparative study revealed the stabilizing effect of Cu incorporation for obtaining stable excellent performance. These findings underscore the potential of introducing an appropriate amount of Cu to achieve stable and superior microwave dielectric properties in MgSiO 3 ceramics, paving the way for practical applications in 5G communication.
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
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xi Wang,Fangyi Huang,Jiaqing Du,Hua Su,Yuanxun Li,Mingshan Qu,Xiaoli Tang
For matching formulation of Ba 0.8−x Ca x Sr 0.2 CuSi 2 O 6 (BSCS-Ca x ) (x = 0–0.1) ceramics with low-temperature co-fired ceramic materials, in this study, BSCS-Ca x ceramics were synthesized by a solid-state reaction method, Further, the sintering temperature was reduced to 925 °C by adding a small amount of LBSCA glass (0.4 wt.%) and BSCS-Ca x +0.4wt.% LBSCA (BSCS-Ca x -L) ceramics were obtained. X-ray diffraction analysis revealed that the BSCS-Ca x -L ceramics consisted of three phases. The incorporation of Ca 2+ ions did not introduce any new phases. Scanning electron microscopy images showed that the doping of Ca 2+ promoted the grain growth of BSCS-Ca x -L ceramics. Raman spectra were used to investigate the lattice vibrations and crystal structure properties. Energy-dispersive spectroscopy point scans of ceramic samples co-fired with Ag showed that the BSCS-Ca x -L ceramics did not react with Ag, and thus ceramics were chemically compatible with Ag. The best microwave dielectric properties of BSCS-Ca x -L ceramics, including ε r = 7.84, Q×f = 42,500 GHz, and τ f = −16 ppm⋅°C −1 , were obtained at an optimized value of x = 0.02.
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 MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 16
·13496-13502
·
IF 2.22
Fang Weishuang,Ao Laiyuan,Tang Ying,Li Jie,Xiang Huaicheng,Zhang Zhiwei,Du Qianbiao,Fang Liang
Recently, there have been considerable interests in the Li-containing spinel oxides as promising microwave dielectric materials. Li loss at elevated temperatures, however, is known to be inevitable, resulting in deterioration on dielectric performances. Here the influence of Li nonstoichiometry on the microwave dielectric properties of Li 2 ZnGe 3 O 8 , a spinel oxide, was reported. An appropriate level of Li excess enhanced the densification of Li 2 ZnGe 3 O 8 and increased dielectric performances. In contrast, high level of Li excess induced the formation of the secondary phase of Li 2 ZnGeO 4 confirmed by XRD and Raman spectra, which in turn lowered the dielectric properties. Typically, a composition with x = 0.075, in the Li 2(1+ x ) ZnGe 3 O 8 ceramics exhibited the enhanced microwave dielectric properties with ε r = 10.68, Q × f = 77,300 GHz (at 13.3 GHz), and τ f = − 70.35 ppm/°C when sintered at 940 °C for 4 h. Moreover, these compounds have well chemical compatibility with the silver electrodes.
研究领域:
材料科学
·
陶瓷学
·
电子材料
✓ 已验证
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
·
电子材料
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Ying Tang,Huan Li,Jie Li,Weishuang Fang,Yang Yang,Zhiyuan Zhang,Liang Fang
Ca 3- x Mg 1+ x LiV 3 O 12 (0 ≤ x ≤ 1) ceramics with cubic-garnet-structure were synthesized by the solid-phase reaction. The replacement of Ca 2+ with the smaller Mg 2+ exerted an increasingly strong “rattling” effect at the A-site of Ca 3- x Mg 1+ x LiV 3 O 12 . With increased Mg 2+ , ε r increased from 10.5 ± 0.1 to 15.4 ± 0.1 and ε corr increased from 11.0 ± 0.1 to 16.0 ± 0.1, whereas the theoretical ε th decreased from 12.0 ± 0.1 to 10.5 ± 0.1. ε corr was higher than ε th due to the “rattling” effect. The enhanced “rattling” effect caused τ f to increase rapidly from –64.1 ± 1.0 ppm/°C to +267.2 ± 1.0 ppm/°C. With increased x , Q × f decreased from 74,700 ± 500 GHz to 15,370 ± 500 GHz, due to the decreased packing fraction, increased FWHM of the A 1g modes, and enhanced “rattling” effect. Additionally, the chemical compatibility between Ca 2.75 Mg 1.25 LiV 3 O 12 and Ag electrodes was confirmed, indicating this material’s potential for LTCC .
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Qi Yuan,Sen Wang,Gaobin Liu,Shuai Yan
Microwave dielectric ceramics (MWDCs) are prone to mechanical failure, and improving the mechanical properties of MWDCs is of significance for their application under extreme conditions. Novel high-entropy R(Nb 1- x Ta x ) 2 O 6 (R = Mg 0.2 Mn 0.2 Co 0.2 Ni 0.2 Zn 0.2 ) ceramics were prepared by the solid-phase reaction method. The single-phase and composite solid solutions of the R(Nb 1- x Ta x ) 2 O 6 series were successfully prepared, as evidenced by XRD, Raman spectra, and combined with EDS energy spectrum analysis. The average grain size was found to increase with the Ta 5+ content, while the grain dispersion exhibited a trend of increasing and then decreasing, resulting in a trend of increasing and then decreasing Q× f . The replacement of Nb 5+ by Ta 5+ has been demonstrated to improve τ f and enhance the mechanical properties. An increase in Ta 5+ content from 0.5 to 0.75 results in a significant enhancement in ε r and mechanical properties, which is primarily attributed to the generation of the RTa 2 O 6 phase. When x = 1, the R(Nb 1- x Ta x ) 2 O 6 ceramics exhibit excellent microwave dielectric properties (ε r = 31.28, Q× f = 20,722, τ f = 48.36) and the most favorable mechanical properties ( H v = 7.99 GPa, σ = 882 MPa, TRS = 237.7 MPa). This study provides a new idea to improve the mechanical properties of MWDCs.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Journal of Advanced Ceramics
·
2020
·Vol. 9
·期 4
·471-480
·
IF 2.889
Huang Fangyi,Su Hua,Li Yuanxun,Zhang Huaiwu,Tang Xiaoli
In this study, low-temperature fired CaMg 1− x Li 2 x Si 2 O 6 microwave dielectric ceramics were prepared via the traditional solid-state reaction method. In this process, 0.4 wt% Li 2 CO 3 -B 2 O 3 -SiO 2 -CaCO 3 -Al 2 O 3 (LBSCA) glass was added as a sintering aid. The results showed that ceramics consisted of CaMgSi 2 O 6 as the main phase. The second phases were CaSiO 3 always existing and Li 2 SiO 3 occurring at substitution content x > 0.05. Li + substitution effectively lowered sintering temperature due to 0.4 wt% LBSCA and contributed to grain densification, and the most homogeneous morphology could be observed at x = 0.05. The effects of relative density, the second phase, and ionic polarizability on dielectric constant (ε r ) were investigated. The quality factor ( Q × f ) varied with packing fraction that concerned the second phase. Moreover, the temperature coefficient of the resonant frequency (τ f ) was influenced by MgO 6 octahedral distortion and bond valence. Excellent dielectric properties of the CaMg 1− x Li 2 x Si 2 O 6 ceramic was exhibited at x = 0.05 with ε r = 7.44, Q × f = 41,017 GHz ( f = 15.1638 GHz), and τ f = −59.3 ppm/°C when sintered at 900 °C. It had a good application prospect in the field of low-temperature co-fired ceramic (LTCC) substrate and devices.
研究领域:
材料科学
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2018
·Vol. 101
·期 9
·4038-4043
·
IF 2.956
Wen Bin Hong,Lei Li,Meng Cao,Xiang Ming Chen
NaCl ceramics were prepared by room-temperature cold sintering using moistened NaCl powder with 4 wt% water and dry pressing using dehydrated powder. When the applied uniaxial pressure is low, the relative density of dry-pressed NaCl ceramic is significantly lower than that of cold-sintered ceramic, while the former is 98.5%-99.3% and much higher than the latter (94.3%-94.6%) for high applied pressure of 200-300 MPa. The uniaxial pressure-induced plastic deformation dominates the densification of dry-pressed NaCl ceramic, and also plays a role during cold sintering as well as the dissolution-precipitation process. The lower density of cold-sintered NaCl ceramic under high applied pressure is attributed to the trapped water in ceramic body during cold sintering. Besides, the presence of water always promotes the microstructural homogeneity, which is responsible for the much higher Qf value of cold-sintered NaCl ceramic. The optimal microwave dielectric properties with ε r = 5.55, Qf = 49 600 GHz, and τ f = −173 ppm/°C are obtained in cold-sintered NaCl ceramic under the applied pressure of 300 MPa, indicating that it is a promising candidate as a microwave dielectric material.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Fangyi Huang,Hua Su,Yulan Jing,Yuanxun Li,Qihai Lu,Xiaoli Tang
Herein, glass-free microwave dielectric ceramics CaMg 0.9-x Li 0.2 Zn x Si 2 O 6 (x = 0–0.36) with excellent microwave dielectric properties were prepared via traditional solid-state reaction method. Phase composition and crystalline structure were identified using X-ray diffraction (XRD), which confirmed that the ceramics contained more than one phase. Rietveld refinement method was utilized to analyze XRD data and obtain structural information, such as lattice parameters. SEM photographs showed that Zn 2+ substitution could effectively promote densification of the ceramics. Microwave dielectric properties were obviously influenced by the combination of multiple phases. Combined with Raman spectra, influences of Raman shift and FWHM of vibration peaks on microwave dielectric properties were determined. The CaMg 0.9-x Li 0.2 Zn x Si 2 O 6 ceramic exhibited high performance at x = 0.28 with: Q × f = 68,190 GHz, ε r = 7.51 and τ f = −68 ppm/°C, when sintered at 900 °C. The studied ceramics are promising candidates for LTCC application.
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
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Jinxin Bi,Yunjuan Niu,Haitao Wu
Low-loss novel Li 4 Mg 3 Ti 2 O 9 dielectric ceramics with rock-salt structure were prepared by a conventional solid-state route. The crystalline structure, chemical bond properties, infrared spectroscopy and microwave dielectric properties of the abovementioned system were initially investigated. It could be concluded from this work that the extrinsic factors such as sintering temperatures and grain sizes significantly affected the dielectric properties of Li 4 Mg 3 Ti 2 O 9 at lower sintering temperatures, while the intrinsic factors like bond ionicity and lattice energy played a dominant role when the ceramics were densified at 1450 °C. In order to explore the origin of intrinsic characteristics, complex dielectric constants ( ε ’ and ε ’’ ) were calculated by the infrared spectra, which indicated that the absorptions of phonon oscillation predominantly effected the polarization of the ceramics. The Li 4 Mg 3 Ti 2 O 9 ceramics sintered at 1450 °C exhibited excellent properties of ε r =15.97, Q· f =135,800 GHz and τ f =−7.06 ppm/°C. In addition, certain amounts of lithium fluoride (LiF) were added to lower the sintering temperatures of matrix. The Li 4 Mg 3 Ti 2 O 9 −3 wt% LiF ceramics sintered at 900 °C possessed suitable dielectric properties of ε r =15.17, Q· f =42,800 GHz and τ f =−11.30 ppm/°C, which made such materials promising for low temperature co-fired ceramic applications (LTCC).
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
危险品化学品经营许可证（带存储）