CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 30
·65060-65066
·
IF 5.6
Hui Yan,Yue Ma,Yong Shang,Yun Wang,Kaixin Song,Guoda Xie,Bo Wu,Xingang Ren,Xianliang Wu,Gang Wang
A series of novel low-permittivity microwave dielectric ceramics with the compositions of (1- x ) BaY 2 Si 3 O 10 - x Ba 5 Si 8 O 21 (0.3 ≤ x ≤ 0.7) and 0.4 BaY 2 Si 3 O 10 -0.6 Ba 5 Si 8 O 21 - y wt% LiF (1 ≤ y ≤ 3) were successfully synthesized using solid-state reaction sintering. The phase evolution and microwave dielectric properties of these ceramics were systematically studied. X-ray diffraction analysis indicated the coexistence of BaY 2 Si 3 O 10 and Ba 5 Si 8 O 21 phases in the (1- x ) BaY 2 Si 3 O 10 - x Ba 5 Si 8 O 21 system, with no secondary phases detected. In contrast, an additional Ba 2 Si 3 O 8 phase was identified in the LiF-modified composition (0.4 BaY 2 Si 3 O 10 -0.6 Ba 5 Si 8 O 21 - y wt% LiF (1 ≤ y ≤ 3)). Moreover, the Ba 5 Si 8 O 21 phase was found to effectively tune the temperature coefficient of resonant frequency (τ f ) to near-zero values in both systems. Excellent microwave dielectric properties were obtained for the 0.4 BaY 2 Si 3 O 10 -0.6 Ba 5 Si 8 O 21 - 2 wt% LiF ceramic, exhibiting a permittivity ( ε r ) of 7.45, a quality factor ( Q × f ) of 13,152 GHz, and a τ f value of −3.17 ppm/°C. This composition also showed good chemical compatibility with silver electrodes, suggesting its potential for use in low-temperature co-fired ceramic (LTCC) applications.
研究领域:
材料科学
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陶瓷
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微波介质材料
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电子材料
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低温共烧陶瓷（LTCC）技术
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产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2015
·
IF 4.762
Pengjiu Wang,Xuhui Xu,Dacheng Zhou,Xue Yu,Jianbei Qiu
Visible-light persistent phosphors are commonly used as self-sustained night vision and fluorescence labeling materials. From the inspiration of the structure of six-membered rings plane in Ba4(Si3O8)2, a similar structure of Ba5Si8O21 is expected that could exhibit more excellent phosphorescence property. In this Article, we report a novel visible long-lasting luminescence phosphor of Eu2+/Dy3+ codoped Ba5Si8O21 for the first time. Ba5Si8O21:Eu2+,Dy3+ phosphor could be activated effectively by sunlight or even in severe weather conditions, which is mainly attributed to the broad excitation spectrum (200–455 nm) and highly responds to UV-A and violet-light in the solar spectrum. After activation, Ba5Si8O21:Eu2+,Dy3+ emits intense emission at 380–680 nm with persistent phosphorescence beyond 16 h. Moreover, it exhibits excellent and stable phosphorescence even in water, indicating that Ba5Si8O21:Eu2+,Dy3+ will be a all-weather material that can be effectively and repeatedly charged by natural daylight in all kinds of open-air environments. Furthermore, the quantum tunneling behavior was illustrated in the afterglow mechanism.
研究领域:
材料科学
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发光材料
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光学性质
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荧光粉
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固态化学
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DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2016
·Vol. 34
·期 5
·453-457
·
IF 2.188
Zhiliang DONG,Yi QIN,Yong YANG,Dacheng ZHOU,Xuhui XU,Jianbei QIU
A series of Ba 5 Si 8 O 21 :0.02Eu 2+ ,0.09RE 3+ persistent phosphors were synthesized by the solid-state reaction method. The measurement results of photoluminescence (PL), phosphorescence and thermoluminescence (TL) were analysed and discussed. The XRD results showed that samples codoped with different RE 3+ were Ba 5 Si 8 O 21 single pure phase. Under the excitation, all samples exhibited a broad Eu 2+ characteristic emission, and the La 3+ co-doped sample emitted the brightest photoluminescence even though its persistent luminescence property was the worst because of the weakest electronegativity. However, Nd 3+ electronegativity was suitable, thus after activation, the Ba 5 Si 8 O 21 :Eu 2+ ,Nd 3+ sample had the best persistent luminescence performance with the highest phosphorescence intensity and the persistent luminescence decay time beyond 8 h. The Nd 3+ co-doped sample also had the largest thermoluminescence integral area which proved effectively it had longer persistent luminescence time. The luminescence mechanism was also proposed to study the photoluminescence and persistent luminescence process. These results showed that RE 3+ electronegativities were distinctly important for persistent phosphors and choosing suitable electronegativity codopant was conducive to enhancing the phosphorescent performance.
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Hui Yan,Weiwei Wang,Yue Ma,Yong Shang,Lingxiu Shu,Yun Wang,Yue Xu,Bo Wu,Xingang Ren,Xianliang Wu,Gang Wang
Thermally stable x Ba 5 Si 8 O 21 - (1- x ) Ba 2 Si 3 O 8 and x Ba 5 Si 8 O 21 - (1- x ) Ba 2 Si 3 O 8 - z wt% LiF ceramics were successfully synthesized via a conventional solid-state reaction method. In the x Ba 5 Si 8 O 21 - (1- x ) Ba 2 Si 3 O 8 (0.1 ≤ x ≤ 0.8) ceramics, only Ba 5 Si 8 O 21 and Ba 2 Si 3 O 8 phases coexisted, with their phase contents confirmed by the Rietveld refinements. The 0.4Ba 5 Si 8 O 21 -0.6Ba 2 Si 3 O 8 ceramic, composed of 40.98 wt% Ba 5 Si 8 O 21 and 59.02 wt% Ba 2 Si 3 O 8 phases, exhibited near-zero τ f and moderate Q × f values. The phase composition controlled the τ f and Q × f values of x Ba 5 Si 8 O 21 - (1- x ) Ba 2 Si 3 O 8 (0.1 ≤ x ≤ 0.8) ceramics. Moreover, the addition of 3 wt% LiF as a sintering aid reduced the sintering temperature of the 0.4Ba 5 Si 8 O 21 -0.6Ba 2 Si 3 O 8 ceramic to 875 °C, while no other secondary phases were detected in the 0.4Ba 5 Si 8 O 21 -0.6Ba 2 Si 3 O 8 - z wt% LiF ceramics. The 0.4Ba 5 Si 8 O 21 -0.6Ba 2 Si 3 O 8 -3 wt% LiF ceramic demonstrated a dense microstructure and favorable microwave dielectric properties ( ε r = 7.44, Q × f = 8293 GHz and τ f = 2.37 ppm/°C), highlighting its potential for low-temperature co-fired ceramic (LTCC) applications.
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产品关联
DOI
高影响因子
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