CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Shuqun Wang,Hua Su,Fangyi Huang
In this work, two low-temperature co-fired silicate ceramics (CaMg 0.9- x Li 0.2 Co x Si 2 O 6 , x = 0.15–0.75, CMLCS; CaMg 0.9-y Li 0.2 Sr y Si 2 O 6 , y = 0, 0.05, 0.1–0.5, CMLSS) were synthesized via solid-state reaction method with 0.5 wt%LBSCA glass addition. CMLCS and CMLSS were densely sintered at 925 °C, and had good chemical compatibility with silver. Optimal microwave dielectric properties ( ε r = 6.71, Q×f = 30124 GHz, and τ f = −79.06 ppm/°C) and ( ε r = 6.78, Q×f = 32530 GHz, and τ f = −52.99 ppm/°C) were obtained for CMLC 0.15 S and CMLS 0.05 S respectively. With increase in Co and Sr substitution, XRD and Raman spectra showed that second phases were produced, and densification process of CaMgSi 2 O 6 -based ceramics was promoted. Dielectric constant was influenced by relative density, Raman shift and second phase. The parameter Q×f was affected by the FWHM of Raman peaks as well as extrinsic factors that affected the temperature coefficient of resonant frequency. Therefore, the results suggested the potential of these two ceramics as candidates for LTCC application.
研究领域:
材料科学
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电气工程
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陶瓷
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Tao Que,Yang Lu,Yiting Shan,Kai Huang,Fei Liu,Xiang Ding,Hongqing Zhou
The effects of CaO additive on the phase composition, sintering behaviour, microstructure, and properties of CaO–B 2 O 3 –SiO 2 (CBS) glass-ceramics were investigated. The results revealed that a small amount of added CaO (0.5 wt%, 1 wt%) facilitated the transformation of α-CaSiO 3 to β-CaSiO 3 and improved the crystallinity. When the amount was greater than 1 wt%, it weakened this transformation and also decreased the crystallinity. The pure CBS sample needed a sintering temperature of 850 °C for maximum densification, whereas the CaO-added samples achieved densification at a sintering temperature of 750–770 °C. The addition of an appropriate amount of CaO significantly enhanced the densification, dielectric properties , and flexural strength of CBS glass-ceramics. However, the addition of CaO had minimal impact on the coefficient of thermal expansion (CTE), which varied from 7.69 to 8.51 ppm/°C. The sample doped with 1 wt% CaO was sintered at 770 °C for 15 min, and it exhibited fairly ideal performance with a bulk density of 2.64 g/cm 3 , ε r of 6.43, tanδ of 0.9 × 10 −3 (15 GHz), and a CTE value of 7.69 ppm/°C.
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高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Fangyi Huang,Jiaqing Du,Xiaoli Tang,Qin Zhang,Xingyu Huo,Yuanxun Li,Xian Jian,Hua Su
Ba 0.8 Sr 0.2 CuSi 2 O 6 ceramics have a low dielectric constant, which is useful for low-latency 5G communication. To enable the preparation of Ba 0.8 Sr 0.2 CuSi 2 O 6 low-temperature co-fired ceramic (LTCC) materials, LBSCA and LBBS were used in this paper to reduce the sintering temperature of Ba 0.8 Sr 0.2 CuSi 2 O 6 . The effects of LBSCA and LBBS on the phase composition, densification, microscopic morphology, and vibrational characteristics of the ceramics were investigated by X-ray diffraction, scanning electron microscopy, density measurements, and Raman spectroscopy , and the causal factors influencing the microwave dielectric properties with the addition of glass were analyzed. It was found that 0.4 wt% LBSCA glass and 1 wt% LBBS glass reduced the sintering temperature to 925 °C, and these prepared ceramics had excellent microwave dielectric properties. The ceramic prepared with 0.4 wt% LBSCA glass had an ε r value of 7.672, Q × f value of 37193 GHz, and τ f value of −14.93 ppm/°C, while the ceramic prepared with 1 wt% LBBS glass had an ε r value of 7.512, Q × f value of 32136 GHz, and τ f value of −13.92 ppm/°C. The phase composition of the ceramics did not significantly change, indicating that neither glass reacted with the ceramics. The ε r value was affected by both density and Raman shift, the trend in the Q × f values was consistent with the density, and the τ f value decreased with increasing glass content, which was attributed to the liquid phase generated by the glass in the ceramic. In addition, co-firing these glass-doped ceramics with Ag at a low temperature resulted in good chemical compatibility. Combined with the near-zero τ f , these results demonstrate the excellent promise of these two ceramics as alternative materials for LTCC microwave devices and their application in 5G communication.
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
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2022
·
IF 5.532
Zhuo Xing,Chi Ma,Juhai Weng
Dense LiCuVO 4 ceramics with a relative density of 95% were facilely fabricated using a conventional solid-state method at low temperatures (∼660 °C). Promising microwave dielectric properties were obtained with a moderate relative permittivity ( ε r ) of 16.9 ± 0.3 and a quality factor ( Q × f ) of 15,200 ± 300 GHz, but poor temperature stability of the resonance frequency (τ f ∼ −61.5 ± 3 ppm/°C). To compensate for the negative τ f value, rutile TiO 2 with a positive τ f value was added to form a series of composite ceramics (1- x )LiCuVO 4 - x TiO 2 . As regards, a zero-close τ f value (∼−1.4 ppm/°C) was achieved at x = 0.6 compositions with an ε r of 18.6 ± 0.3 and a Q × f of 18,000 ± 400 GHz. Additionally, the LiCuVO 4 ceramic has good chemical compatibility with silver electrodes. All results support the prospective applications of LiCuVO 4 in low-temperature cofired ceramics (LTCC) as substrates.
研究领域:
材料科学
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电气工程
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陶瓷
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DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 5
·1953
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IF 3.748
Yujun Gao,Jingjing Feng,Feng Liu,Zhifu Liu
Silver paste is widely used for low-temperature co-fired ceramic (LTCC) electrodes. In this work, a kind of LTCC silver paste for fine-line screen-printing was developed by considering the effect of the organic vehicle on rheological behavior and screen-printing properties. A step-by-step volatilization mode was applied to screen the mixed organic solvent ofα-terpineol, 2-(2-butoxyethoxy) ethyl acetate (BCA) and dibutyl phthalate (DBP). Theα-terpineol:BCA:DBP ratio of 5:2:3 is selected by considering the volatility, viscosity, and pseudoplasticity of the organic vehicle. Both viscosity and pseudoplasticity of shear-thinning increase with the increase of ethyl cellulose (EC) organic binder content. Three interval thixotropy test (3ITT) was conducted to discuss the thixotropy of silver paste. The minimum printing line width of 13.27 µm is obtained using silver paste with 10 wt% EC, confirming that the homemade paste has good printability.
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
·
2024
·
IF 5.1
Mo Wei,Juan Liu,Bing Liu,Kai Xin Song,Cheng Chao Hu,Yu Hui Huang
Alkaline earth metal fluorides, BaF 2 and SrF 2 , are promising low-permittivity ceramics with excellent microwave dielectric properties. However, achieving ideal densifications in BaF 2 and SrF 2 ceramics remains challenging due to their low surface-free energy. In this study, the sintering characteristics of BaF 2 and SrF 2 ceramics are optimized via forming (1– x )BaF 2 - x SrF 2 ( x = 0.2, 0.4, 0.5, 0.6, and 0.8) solid solution ceramics. X-ray diffraction (XRD) patterns and Raman spectra provide compelling evidence for successfully forming (1– x )BaF 2 - x SrF 2 solid solutions across the entire composition range. The solid-solution effect significantly enhances densification at a much lower sintering temperature of around 825 °C. Notably, 0.6BaF 2 -0.4SrF 2 ceramics exhibit the optimal microwave dielectric properties with a permittivity ( ε r ) of 7.26, quality factors ( Qf ) of 61,006 GHz at 10 GHz and 106,000 GHz at 25 GHz, and a temperature coefficient of resonant frequency ( τ f ) of −97.46 ppm/ ° C. Additionally, the advancement of low-temperature co-fired ceramic (LTCC) technology for high-density electronic packaging presents a significant challenge in achieving compatibility between the coefficient of thermal expansion (CTE) of the packaged components. The 0.6BaF 2 -0.4SrF 2 ceramics exhibit a significantly higher CTE of 21.67 ppm/ ° C compared to most low- ε r ceramics (usually below 10 ppm/ ° C), resulting in better CTE matching with organic laminates and metal electrodes. Therefore, BaF 2 -SrF 2 solid solution ceramics, addressing the need for low- ε r , high- Qf , and high CTE, offer a potential solution for high-reliability LTCC electronics.
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 MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2023
·Vol. 34
·期 5
·1-10
·
IF 2.8
Lu Yang,Shan Yiting,Guo Xiang,Zhang Yajuan,Feng Jingmin,Zhou Hongqing
CaO-B 2 O 3 -SiO 2 /Al 2 O 3 /SiO 2 composites were developed for low-temperature co-fired ceramic (LTCC) applications, and the sintering behavior, phase compositions, microstructure, dielectric properties, and mechanical properties were investigated in the present work. The results showed that an appropriate amount of silica could reduce the dielectric constant and improve the dielectric properties of the composite material, which is of great significance for improving the signal transmission rate, and reducing the signal transmission loss and delay. The CBS/Al 2 O 3 /SiO 2 glass ceramics with 32 wt% Al 2 O 3 and 16 wt% SiO 2 sintered at 850 °C for 30 min achieved excellent comprehensive performance with buck density of 2.88 g/cm 3 , ε r of 6.76, tanδ of 1.12 × 10 −3 (7 GHz), CTE value of 7.42 ppm/ °C, and flexural strength of 207.8 MPa. Moreover, the composites matched well with the silver electrode, establishing an extremely promising material for LTCC applications.
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 ALLOYS AND COMPOUNDS
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2022
·
IF 6.371
Mao Zeng,Xiaohui Wu,Hua Su,Jingkang Xu,Xiaoli Tang
Herein, Li 1.0 Nb 0.6 Ti 0.5 O 3 + x wt% BaCu(B 2 O 5 ) (0 ≤ x ≤ 0.8) ceramics were synthesized via the traditional solid-state reaction method. The sintering behavior, phase, Raman spectra, microwave dielectric characteristics, and chemical compatibility with Ag of the Li 1.0 Nb 0.6 Ti 0.5 O 3 + x wt% BaCu(B 2 O 5 ) samples were comprehensively analyzed. The results show that doping the Li 1.0 Nb 0.6 Ti 0.5 O 3 ceramics with BaCu(B 2 O 5 ) can not only reduce the sintering temperature from 1100 °C to 950 °C but also effectively improve the density and quality factor ( Q × f ) of the Li 1.0 Nb 0.6 Ti 0.5 O 3 samples. Additionally, Li 1.0 Nb 0.6 Ti 0.5 O 3 + 0.4 wt% BaCu(B 2 O 5 ) samples, which were sintered at 950 °C for 4 h, exhibit excellent microwave dielectric properties ( ε r = 61.4, Q × f = 6423 GHz, and τ f = 27.5 ppm/°C) and excellent chemical compatibility with Ag, which makes these ceramics potential candidate materials in the low-temperature co-fired ceramic technology.
研究领域:
材料科学
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电子材料
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2018
·Vol. 29
·期 24
·20546-20553
·
IF 2.324
Xin Miao,Zhang Liming,Chang Yi,Ren Luchao,Luo Xianfu,Zhou Hongqing
This present work aimed to attain a high-performance tape for LTCC application by using butyl benzyl phthalate as plasticizer in tape casting slurry of CaO–SiO 2 –B 2 O 3 glass–ceramics. The plasticizing mechanism of butyl benzyl phthalate in suspensions was demonstrated in depth. Dried droplets of binder were prepared to preliminarily judge the compatibility of binder and plasticizer, and the optimal additive amount was determined by rheological characteristic. In addition, a series of qualitative and quantitative methods were carried out to assess the tensile strength and elongation of green tapes, microwave properties and densification of sintered bodies. The experimental results revealed that when the addition of BBP was up to 45 wt%, tape casting slurries had the optimal fluidity and green tapes obtained the excellent performance with density at 1.65 g/cm 3 , tensile strength at 1.43 MPa and elongation at 13.4%. Meanwhile, sintered bodies fired at 850 °C achieved the highest density at 2.42 g/cm 3 with ε r = 5.94 and tanδ = 10 × 10 −4 at 10 GHz.
研究领域:
材料科学
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陶瓷工程
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电子材料
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 1
·1-14
·
IF 2.8
Zhang Yajuan,Lu Yang,Shan Yiting,Wang Jie,Feng Jingmin,Zhou Hongqing
Herein, (1 − x )CaO–Al 2 O 3 –B 2 O 3 –SiO 2 (CABS)/ x Ba(Mg 1/3 Nb 2/3 )O 3 (BMN; x = 0.4, 0.45, 0.5, 0.55, and 0.6) composites were prepared, and the impact of the BMN and low-softening-point glass content in CABS/BMN composites on the sintering, dielectric, thermal, and mechanical properties of the prepared composites was investigated. The main crystal phases of the CABS/BMN composites are BMN and Ba 2 NaNb 5 O 15 (BNN). The crystallization temperature of the composite was reduced by an appropriate amount of BMN. BMN ceramics (40–60 wt%) was added to the CABS glass, and the composites were sintered at 800 °C, 825 °C, 850 °C, 875 °C, and 900 °C. To elucidate the influence mechanism of different glass contents and sintering temperatures on the properties of the composites, different qualitative and quantitative instruments were used to study the composite properties. The CABS/BMN composite containing 50 wt% CABS glass sintered at 875 °C exhibits the following ideal properties: volumetric density of 3.57 g/cm 3 , dielectric constant of 17.97, dielectric loss of 6 × 10 −4 , \(Q \times f\) value of 10,947 at 9.5 GHz, bending strength of 157.7 MPa, and coefficient of thermal expansion of 5.9 ppm/K. Microstructure analysis reveals that the microstructure of the composite is dense, the pores are few, the surface morphology is uniform and flat, and the composite does not react with silver electrodes, making it suitable for applications utilizing medium dielectric constant low-temperature co-fired ceramic materials at low sintering temperatures.
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
·
2023
·
IF 6.2
Xiaohui Wu,Yulan Jing,Yuanxun Li,Hua Su
The comprehensive properties and sintering temperature of microwave dielectric ceramics are the key factors limiting their practical application. In this work, a novel strategy of complex (Co 1/3 Nb 2/3 ) 4+ ions substituted and adding glass (Li 2 O-B 2 O 3 - SiO 2 -CaO-Al 2 O 3 : LBSCA) was proposed to greatly enhance the microwave dielectric properties of Ba 3 Ti 4- x (Co 1/3 Nb 2/3 ) x Nb 4 O 21 (0 ≤ x ≤ 12 mol%, x CN-BTN) ceramics. A new ceramic of (Co 1/3 Nb 2/3 ) 4+ substitution improved hexagonal phase BTN was successfully fabricated and systematically investigated. As the increased of (Co 1/3 Nb 2/3 ) 4+ ions concentration, the Q× f was greatly increased because of higher packing fraction, and the reduction in the [Nb1/Ti1O 6 ] octahedral distortion caused great changes of τ f . Besides, the P-V-L theory revealed that the Ti/Nb ratio greatly contributed in permittivity ε r , and the Nb-O bonds mainly affected dielectric loss, especially in Nb(1)-O2(1) bond. As a result, the superior microwave dielectric properties were obtained in 6CN-BTN ceramic sintered at 950 °C: ε r ∼40.99 ± 0.48, Q× f ∼17,310 ± 565 GHz, and τ f ∼8.62 ± 4.34 ppm/°C. More encouragingly, 6CN-BTN showed good compatibility with silver, making it a promising K 40 LTCC material for filter and dielectric resonators . This study presented a new strategy to improve the properties of BTN-based materials by complex ions substitution, which was expected to provide a general approach for the design of advanced microwave dielectric ceramics for other material systems.
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
ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Dongxu Wang,Kai Yin,Yue Zhang,Hongmin Lu,Lulu Hou,Hongjing Zhao,Mingwei Xing
Endemic fluorosis (EF) has been listed as one of the serious public health problems in many countries. Long-term exposure to high fluoride can lead to severe neuropathological damage to the brain. Although long-term research has revealed the mechanism of some brain inflammation caused by excessive fluoride, the role of intercellular interactions, especially immune cells, in brain damage is still unclear. Fluoride can induce ferroptosis and inflammation in the brain in our study. A co-culture system of neutrophil extranets and primary neuronal cells showed that fluoride can aggravate neuronal cell inflammation by causing neutrophil extranets (NETs). In terms of the mechanism of action, we found that fluoride leads to the opening of calcium ion channels by causing neutrophil calcium imbalance, which in turn leads to the opening of L-type calcium ion channels (LTCC). Extracellular free iron enters the cell from the open LTCC, leading to neutrophil ferroptosis, which releases NETs. Blocking LTCC (nifedipine) rescued neutrophil ferroptosis and reduced the generation of NETs. Inhibition of ferroptosis (Fer-1) did not block cellular calcium imbalance. In summary, our study explores the role of NETs in fluoride-induced brain inflammation and suggests that blocking calcium channels may be one of the possibilities to rescue fluoride-induced ferroptosis.
研究领域:
神经科学
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免疫学
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毒理学
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细胞生物学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）