CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Ce Li,Xu Zhang,V.C. Onah,Weiling Yang,Zhuang Leng,Xiliang Jiang,Fangming Zhang,Shasha Li,Yong Zhang,Yu Han,Huisheng Liu,Chun Li,Dingfu Zhou,Fanming Zeng
In analyzing the effect of alkali metal and alkaline earth metal oxide on the properties of tellurite glass , a series of tellurite glass samples doped with alkali metals and alkaline earth metals were prepared based on the TeO 2 -WO 3 -GdF 3 glass system by melt quenching method. Through tests and comprehensive analysis, the results show that after the F − ions successfully enter the glass network, the substitution of TeO 2 by alkali and alkaline earth metals could reduce the molar volume , which means the glass becomes more compacted. The influence on the glass network is mainly shown in [TeO 3 ] and [TeO 4 ] units. Alkali metals and alkaline earth metals could increase the asymmetry of the TWG: Eu 3+ glass network, shorten the critical distance, and increase luminescence intensity by 8.6 times and improve color purity to 94%. In addition, alkali metals could prolong the fluorescence lifetime , while alkaline earth metals could shorten it. Te 4+
研究领域:
材料科学
·
光学材料
·
玻璃物理
·
发光光谱学
·
无机化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2013
·
IF 2.108
Yun-fei Zhang,Rui Zhang,Chao-long Yang,Jing Xu,Jian Zheng,Man-geng Lu
Stable acrylate/triethoxyvinylsilane (VTES) core–shell emulsion with different mass ratio of MMA/BA in the core and shell was prepared via a modified micro-emulsion polymerization process. The chemical composition and core–shell structure were investigated by Fourier transform infrared (FTIR) spectrometry, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM), respectively. Effect of MMA/BA mass ratio in the core and shell on the film-forming ability, surface tension of latex was also studied. Finally, water absorption and thermal stability of the latex films were characterized. It was found that the surface tension of emulsion can be reduced to 32.9 N/m when the MMA/BA mass ratio in the shell is 6/4. The water absorption of the latex film could be improved at a proper mass ratio of MMA/BA in core and shell, but adjusting the mass ratio of MMA/BA in the shell has little influence on the thermal stability of latex film. This work provides a method of preparing environment-friendly latex with low surface tension and excellent water resistance for coating applications by regulating the mass ratio of monomers in a modified micro-emulsion polymerization process.
✓ 已验证
产品关联
DOI
高影响因子
Corrosion Communications
·
2021
·
IF 0
Shuaihang Qiu,Huimin Xiang,Fu-Zhi Dai,Hailong Wang,Yanchun Zhou
The protecting materials of reference electrode with good corrosion resistance to molten salts play vital roles in realizing smelting of refractory and rare earth metals through fused salts electrolysis. BaZrO 3 has been considered as a candidate protecting material of reference electrode for its good chemical stability and high-temperature corrosion resistance. However, the unsatisfactory corrosion resistance to molten salts hinders its practical application. In order to enhance the corrosion resistance to molten salts, three perovskite structured high-entropy oxides HE (Ca,Sr,Ba) TM O 3 including (Ca,Sr,Ba)(Zr,Hf)O 3 , (Ca,Sr,Ba)(Zr,Ta)O 3 and (Ca,Sr,Ba)(Zr,Hf,Ta)O 3 , were designed and prepared in this work. The as-prepared HE (Ca,Sr,Ba)(Zr,Hf)O 3 and (Ca,Sr,Ba)(Zr,Hf,Ta)O 3 ceramics are single-phase, while the as-prepared HE (Ca,Sr,Ba)(Zr,Ta)O 3 ceramic contains 11.6 vol.% of (Ca,Sr,Ba) 2 Ta 2 O 7 . These HE (Ca,Sr,Ba) TM O 3 ceramics possess better corrosion resistance to molten NaCl-KCl salts than BaZrO 3 , among which (Ca,Sr,Ba)(Zr,Hf,Ta)O 3 shows the best corrosion resistance to molten NaCl-KCl salts. The mass loss per unite area of HE (Ca,Sr,Ba)(Zr,Hf,Ta)O 3 after corrosion by molten NaCl-KCl salts at 800 °C for 8 h is mere 2.6×10 −6 g/mm 2 which is ca . 1/60 of that of BaZrO 3 (∼1.7×10 −4 g/mm 2 ), and its surface after corrosion is plain and smooth without any new phase detectable after corrosion. It also exhibits better corrosion resistance to molten NaF-KF salts than BaZrO 3 . The mass loss per unite area after corrosion by molten NaF-KF salts at 800 °C for 8 h is only 2.9×10 −5 g/mm 2 which is smaller than that of BaZrO 3 (3.6×10 −5 g/mm 2 ), the corrosion caused by molten NaF-KF salts only occurs on the surface and the thickness of the corrosion layer is mere ∼8 µm, being less than 1/10 of that of BaZrO 3 (∼100 µm). These results indicate that the three HE (Ca,Sr,Ba) TM O 3 , especially (Ca,Sr,Ba)(Zr,Hf,Ta)O 3 , are promising as protecting materials of reference electrode for the smelting of refractory and rare earth metals through fused salts electrolysis.
研究领域:
材料科学
·
冶金工程
·
电化学
✓ 已验证
DOI
DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 29
·10206-10213
·
IF 4.39
Wenyao Zhang,Wenqi Jin,Meng Cheng,Ruonan Zhang,Zhihua Yang,Shilie Pan
Fluorine-containing compounds significantly enrich the diversity of inorganic chemical structures. Here, four alkaline-earth metal difluorophosphates with different space groups, namely NH4Mg(PO2F2)3 (Cmcm) (1), NH4Sr(PO2F2)3 (P) (2), (NH4)2Ba(PO2F2)4 (P2/n) (3) and Ba(PO2F2)2 (I2d) (4), were synthesized and their structures were determined for the first time. 4 is not only the first alkaline-earth-metal difluorophosphate, but also the first difluorophosphate reported to crystallize in the non-centrosymmetric space group I2d of the tetragonal crystal system. All of the three-dimensional (3D) structures of the title compounds consist of isolated (PO2F2)−, AE–O and NH4+ units, while the differences of the cation radius result in various arrangements of the (PO2F2)− units, which leads to diverse crystal structures and the disparate optical anisotropy of the crystals. According to the deep-ultraviolet (DUV) transmittance spectrum, 3 exhibits a short DUV cut off edge (<180 nm). Solid state 19F and 31P magic-angle spinning NMR spectroscopy was used to verify the presence of covalent P–F bonds in 3. The different size effects, as well as the coordination environments of the Mg2+, Sr2+, and Ba2+ cations, on the structures as a whole have been discussed in detail. In addition, the calculated birefringence values were observed to differ from 0.011 to 0.033 for the four compounds.
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产品关联
DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2026
·
IF 6.2
Chenyang Zhan,Zihao Wang,Sisi Liang,Zhi-Ying Zhao,Hanru Chen,Jiahe Yu,Haomiao Zhu
Alkaline earth lithoaluminates with the UCr4C4-type structure have demonstrated considerable potential in achieving narrow-band emissions from Eu 2+ . However, obtaining single-phase powder samples with green-emitting remains challenging. In this study, we address this issue by co-doping Ba 2+ into the novel UCr4C4-type system Sr5/6-xBaxLi17/6Al7/6O4:Eu 2+ , which significantly enhances phase purity and structural homogeneity. This approach not only reduces the emission bandwidth from 66 nm (2241 cm -1 ) to 51 nm (1830 cm -1 ) but also induces a blue shift to 529 nm, fine-tuning the emission into the desired deep green region. Through detailed mechanistic studies-including low-temperature spectroscopy and luminescence decay analysis-we identify the presence of multiple Eu 2+ emission centers associated with distinct Sr 2+ sites. Ba 2+ doping is shown to promote dominant Eu 2+ emission in the green spectral region, thereby facilitating spectral narrowing.The optimized phosphor achieves a high absorption efficiency of 64.6% and an external quantum yield of 22.2%. When integrated into a white LED prototype, it enables a color gamut covering 97.6% of the NTSC (National Television System Committee) standard, outperforming a commercial β-SiAlON:Eu 2+ -based device. This study provides an effective cationic codoping strategy for designing high-performance narrow-band oxide phosphors and highlights a promising candidate for nextgeneration display technologies.
✓ 已验证
产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2020
·
IF 4.089
Chang-Yu Meng,Feng Feng Huang,Qin Yao Li,Lei Geng
Introduction of divalent metal oxides into the TeO2 matrix can produce the chemical formula Mn[TemO2m+n] ≡ (MO)n(TeO2)m, compounds in which divalent metal oxides provide oxygen ions to the parent compound TeO2, to cleave neutral Te–O net to form various tellurium(IV) oxide anion [TemO2m+n]2n− and divalent metal cations as balanced charges. [TemO2m+n]2n− can form isolated anion, discrete polyanion, one-dimensional chain and ribbon polyanion, two-dimensional (2D) layered polyanion, and 3D tunnel polyanion depending on the ratio of MO/TeO2. In this work, a new type of inorganic compound AE2[Ni(Te4O10)Cl2] ≡ [(AEO)2(TeO2)4](NiCl2) (AE = Ca, Sr, Ba, Pb) can be obtained by introducing NiCl2 into the compound AE2[Te4O10] ≡ (AEO)2(TeO2)4 (AE = Ca, Sr, Ba, Pb). In AE2[Ni(Te4O10)Cl2] ≡ [(AEO)2(TeO2)4](NiCl2), AEO acts as a structural shearing agent to cleave the neutral Te–O layered structures of parent TeO2 into [Te4O10]4– anionic fragments, and the introduced NiCl2 acts as an “adhesive” to recombine [TemO2m+n]2n− anionic fragments to form new [Ni(Te4O10)Cl2] anionic framework and does not provide additional oxygen ions to cleave the parent compound TeO2. AE2[Ni(Te4O10)Cl2] compounds feature 2D 2∞[Ni(Te4O10)Cl2] anionic layers composed by TeO4E, TeO3+1E (where E is the lone pair of electrons of TeIV) distorted trigonal bipyramid, and NiO4Cl2 octahedra, and the spaces between 2∞[Ni(Te4O10)Cl2] layers are filled with AE2+ cations (acting as charge balance) as well as E (protruding from sides of the layers). The optical band gaps of AE2[Ni(Te4O10)Cl2] (AE = Ca, Sr, Ba, Pb) were evaluated to be ∼3.69 eV through extrapolating the UV–vis–near-infrared optical absorption spectra. Thermogravimetric and differential scanning calorimetry measurements indicate that Ca-, Sr-, Ba-, and Pb-compounds are stable below 787, 716, 648, and 517 °C, respectively, under flowing N2 atmosphere. The effective moments estimated by Curie–Weiss equation show that the Ni2+ cations of AE2[Ni(Te4O10)Cl2] (AE = Ca, Sr, Ba, Pb) are all in high-spin ground states.
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产品关联
DOI
高影响因子
IEEE TRANSACTIONS ON ELECTRON DEVICES
·
2024
·
IF 2.9
Chenning Wang,Xiaoyu Zhou,Tianqi Jiang,Zhenrui Xu,Esmond A. Balfour,Hao Fu
The high content of Ba and Sc in Ba
$_{\text{3}}$
ScGa
$_{\text{2}}$
O
$_{\text{7.5}}$
and its suitable melting point suggest that it is a candidate for thermionic emission in vacuum electron devices. To study its electron emission capacity, this compound was synthesized at 1300
$^{\circ}$
C by a high-temperature solid-phase method with the stoichiometric mole ratio of BaCO
$_{\text{3}}$
:Sc
$_{\text{2}}$
O
$_{\text{3}}$
:Ga
$_{\text{2}}$
O
$_{\text{3}}$
$=$
6:1:2. The test cathode impregnated with this material had a high emission capacity with the full-space charge current density of 10.2 A/cm
$^{\text{2}}$
at 850
$^{\circ}$
C in the dc mode. The sintered mixture of the compound and tungsten powder reveals that the formation of Ba
$_{\text{3}}$
Sc
$_{\text{2}}$
WO
$_{\text{9}}$
on the cathode surface leads to reduced work function and thus enhanced emission performance. The titled compound is environmentally stable with a low weight gain percentage (4.51%) and a steady phase in the air for 288 h. Coupled with the high emission current density at low temperatures, the cathode impregnated with Ba
$_{\text{3}}$
ScGa
$_{\text{2}}$
O
$_{\text{7.5}}$
compound has superior thermionic cathode properties and promising applications in vacuum electron devices.
研究领域:
材料科学
·
真空电子学
✓ 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）