POWDER METALLURGY AND METAL CERAMICS
·
2022
·Vol. 60
·期 11
·738-747
·
IF 0.913
Sun W.Z.,Huang Z.K.,Lu Y.J.,Liu L.M.,Xiao Z.
Preliminary experiments revealed solid-state reactions in the SiC–TiO 2 –MgO system that resulted in forming TiC compound, providing, thus, a new reaction system for the formation of TiC–SiC ceramic matrix composites. This system’s high-temperature physicochemical reaction and the phase equilibrium relations of TiC–SiC with salt compounds in the SiC–TiO 2 –MgO system will be examined in this paper. The obtained findings may significantly contribute to the composition of TiC–SiC ceramic composites. Solid-state reactions in the SiC–TiO 2 –MgO system were investigated during experimental procedures employing thermodynamic computing. Chemical kinetics of some reactions were highlighted and discussed, including mutual displacement reaction of SiC + TiO 2 = = TiC + SiO 2 to form TiC, the acid-based reaction of MgO with SiO 2 or TiO 2 to form Mg-silicates (Mg 2 SiO 4 , MgSiO 3 ) or Mg-titanates (Mg 2 TiO 4 , MgTiO 3 , MgTi 2 O 5 ), the reduction reaction of 2TiO 2 + C = Ti 2 O 3 + CO (g) with the involvement of excessive TiO 2 . The appearance of Ti 2 O 3 may also be due to significant surface defects of rutile TiO 2 (110) derived from its bulk Ti 3+ defects. However, Mg-silicates and Mg-titanates were not found in the design of the current SiC–TiO 2 –MgO system but the oxide design of the MgO–TiO 2 –SiO 2 system. As the SiC–TiO 2 –MgO ternary system was extended to the SiC–SiO 2 –TiC–TiO 2 –MgO quinary system, the phase relations form a combination of the TiC–SiC phase relations with all salts of the TiO 2 –MgO–SiO 2 system. Experiments confirmed the formation of TiC and its coexistence with SiC and all binary compounds of the TiO 2 –MgO–SiO 2 system, specifying an interaction in the SiC–SiO 2 –MgO–TiO 2 –TiC system. The phase relations of the quinary system were established, followed by constructing its phase diagram relations at 1400°C, which would be beneficial for the compositional design of TiC–SiC, TiC–ceramic, and SiC–ceramic composites.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ISIJ INTERNATIONAL
·
2017
·Vol. 57
·期 1
·62-67
·
IF 1.11
Zijian Su,Yuanbo Zhang,Yingming Chen,Guanghui Li,Tao Jiang
A considerable amount of works were focused on the formation mechanism of calcium ferrite phases during the iron ore sintering process, especially under various O2 content atmospheres at temperatures higher than 1100°C. But little attention has been paid on reactions between CaO and iron oxides in CO–CO2 atmospheres at lower temperatures. In this study, the solid state reaction mechanisms between CaO and Fe3O4 under CO–CO2 atmospheres at 800°C–1100°C were revealed by using XRD, VSM, etc. The results indicated that Ca2Fe2O5 was easily formed under 5–50 vol% CO/(CO+CO2) atmosphere above 850°C via the reaction of 6CaO + 2Fe3O4 +CO2 = 3Ca2Fe2O5 + CO and the reaction would be promoted with increasing the roasting temperature. In the CO–CO2 atmosphere, Fe3O4 is easily oxidized to Fe2O3 in the presence of CaO because CO2 components act as oxidative medium for the oxidation of Fe2+ to Fe3+.
研究领域:
冶金学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Applied Spectroscopy
·
2020
·Vol. 87
·期 4
·753-757
·
IF 0.71
Sun J.,Li Q.,Zhou Q.
Eu 3+ -doped NaLaMo 2 O 8 phosphors were synthesized by a conventional solid-state reaction. The phase and luminescent properties of the synthesized phosphors were investigated in the current work. In NaLaMo 2 O 8 , Eu 3+ ions replace La 3+ ions and form solid compound. This substitution induces the 2θ angles of diffraction peaks to shift to larger values. Under excitation at 395 nm, NaLaMo 2 O 8 :Eu 3+ phosphors exhibit emission bands in the range of 550–725 nm originating from 5 D 0 → 7 F J transitions (J = 0, 1, 2, 3, 4) of Eu 3+ . The strongest emission band corresponds to the 5 D 0 → 7 F 2 transition, which indicates a site of Eu 3+ without inversion symmetry in NaLaMo 2 O 8 . The Eu 3+ concentration has obvious influence on the luminescent properties of NaLaMo 2 O 8 :Eu 3+ phosphors. NaLaMo 2 O 8 :6 mol%Eu 3+ has the strongest excitation and emission intensities.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Chong Ni,Zhen Li,Kai Wang,Yongchao Liu,Yuanyun Dou,Wentao Wu,Hongyu Wang,Yu Yao,Hongfa Xiang,Xuyong Feng
Surface modification is a highly effective strategy to suppress side reactions between electrode materials and electrolytes. The preparation of coated electrode materials generally involves two steps: the synthesis of electrode materials and subsequent surface coating, which is a long and costly process. Here, we report a novel solid-state reaction method to prepare Li 2 ZrO 3 -coated LiCoO 2 in a single step. By controlling the cooling rate, the solid solubility of Zr in LiCoO 2 decreases, resulting in the precipitation of Zr 4+ on the surface and the formation of a Li 2 ZrO 3 coating layer. X-ray photoelectron spectroscopy, combined with a focused ion beam and high-resolution transmission electron microscopy, confirms the uniform Li 2 ZrO 3 coating on the surface of LiCoO 2 . Electrochemical performance testing shows that Li 2 ZrO 3 -coated LiCoO 2 exhibits enhanced cycle stability, even when charged to 4.5 V. After cycling at 1C for 200 cycles, Li 2 ZrO 3 -coated LiCoO 2 maintains a capacity of about 180 mAh g −1 , which is 94 % of the initial 193 mAh g −1 .
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
OPTIK
·
2017
·
IF 0.835
Renping Cao,Kailei Bai,Xing Liu,Wudi Wang,Ting Chen,Siling Guo,Zhiyang Luo,Wensheng Li
A series of CaZn 2 P 2 O 8 :Sm 3+ , Mn 2+ phosphors are synthesized by a solid-state reaction method in air. The crystal structures and luminescence properties are investigated. CaZn 2 P 2 O 8 :Sm 3+ phosphor with excitation 402 nm emits red light in the range of 550–750 nm owing to the 4 G 5/2 → ( 6 H 5/2 , 6 H 7/2 , 6 H 9/2 , and 6 H 11/2 ) transitions of Sm 3+ ion. CaZn 2 P 2 O 8 :Mn 2+ phosphor with excitation 400 nm emits yellow-green light in the range of 500–650 nm due to the 4 T 1 (G) → 6 A 1 transition of the Mn 2+ ion. CaZn 2 P 2 O 8 :Sm 3+ , Mn 2+ phosphor with excitation 400 nm shows a tunable emission in the range of 500–750 nm with changing Sm 3+ or Mn 2+ ion content. The optimal Sm 3+ and Mn 2+ ion concentrations are ∼4 mol% and 3 mol%, respectively.
研究领域:
材料科学
·
光学
·
磷光技术
✓ 已验证
产品关联
DOI
高影响因子
STEEL RESEARCH INTERNATIONAL
·
2022
·Vol. 93
·期 7
·2100788
·
IF 2.126
Hongrui Yue,Gongjin Cheng,Jianxing Liu,Xiangxin Xue,Weijun Zhang
This study proposes a clean and effective routine and aims to solve the problems of material accumulation and hypoxia during roasting vanadium slag. The vanadium slag and CaO 2 powders are mixed, briquetted, and roasted at different parameters. The generated phases are Fe 2 O 3 , Fe–Mg oxides, Fe–Ti oxides, Ca 3 (VO 4 ) 2 , silicate, and SiO 2 after roasting. The solid reaction between V 2 O 5 and CaO is described using the vacancy diffusion mechanism. Ca 2+ (or V 5+ ) jumps and diffuses through the Ca 2+ (or V 5+ ) vacancies in the Ca 3 (VO 4 ) 2 layer and subsequently to the Ca 3 (VO 4 ) 2 /V 2 O 5 (or Ca 3 (VO 4 ) 2 /CaO) interface and reacts with V 2 O 5 (or CaO) and O 2 (decomposed from CaO 2 or transported from the air) to generate Ca 3 (VO 4 ) 2 . The vanadium leaching rate is very sensitive to the roasting parameters of CaO/V 2 O 5 molar ratio, temperature, time, and briquetting pressure. A maximum vanadium leaching rate of 98.31% is achieved with a CaO/V 2 O 5 molar ratio of 3/1, with temperature, time, and briquetting pressure being maintained at 900 °C, 50 min, and 10 MPa, respectively. The present routine, which greatly shortens the roasting time, can be realized through a rotary hearth furnace, and is likely to be accepted by both iron works and the environment due to its effective and clean characteristics.
研究领域:
冶金学
·
环境工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Chenhao Li,Yi Niu,Linlin Yi,Yaoqiang Li,Jia Fu,Fang Tang,Kaiyuan Li,Yanyan Zou
This paper explores the application of zeolitic imidazolate framework-8 (ZIF-8) in pyrolytic disposal of poly(vinyl chloride) (PVC), with the goal of assessing the in situ catalytic removal and capture effect of ZIF-8 on Cl, elucidating the migration pattern of Cl, revealing the mechanism of in situ Cl capture by ZIF-8. The results demonstrate that excellent catalytic and Cl trapping properties are exhibited by ZIF-8, and an additional 311.1 mg/g of organic Cl from PVC is facilitated to be removed at 250 ºC. The catalytic effect enhances Cl trapping at low temperatures. The solid-solid reaction between PVC and ZIF-8 during in situ pyrolysis significantly improves Cl capture compared to ex situ pyrolysis. During in situ pyrolysis, ZIF-8 shows excellent Cl capture between 250 and 350 ºC, where Cl is primarily captured in the solid phase as inorganic Cl. ZIF-8 achieves optimal Cl capture at 300 ºC, reaching a peak HCl removal rate of 89.5 %. At this temperature, the content of solid-phase inorganic Cl reaches a maximum of 442.0 mg/g, accounting for 78.7 wt% of the total Cl content. The key to Cl capture lies in the chemical adsorption sites of Zn²⁺ and organic ligands in the ZIF-8 structure, which can react with Cl in both solid-solid and gas-solid reactions. Additionally, crystals formed during pyrolysis create an adsorption barrier, ultimately enabling efficient Cl capture.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 12
·10487-10493
·
IF 2.324
He Qinjiang,Fu Renli,Zhu Haitao,He Hong,Song Xiufeng,Liu Xuhai
Eu 2+ doped strontium aluminate phosphors Ca y Sr 4−x−y Al 2 O 7 :xEu 2+ (0 ≤ x ≤ 0.1, 0 ≤ y ≤ 0.1) were synthesized via a novel halide-assisted solid-state reaction method. The phase structure and photoluminescence properties of Ca y Sr 4−x−y Al 2 O 7 :xEu 2+ were characterized via X-ray diffraction (XRD) and fluorescence spectrophotometer. The XRD patterns indicate that the α-Sr 4 Al 2 O 7 phase structure with negligible impurities were produced in the samples of Ca y Sr 4−x−y Al 2 O 7 :xEu 2+ (x ≤ 0.1 and y ≤ 0.1) at 1450 °C. Photoluminescence results show that the Ca y Sr 4−x−y Al 2 O 7 :xEu phosphor with NH 4 I as reductant presents typical intense Eu 2+ red emission bands centered at 610 nm while excited by 450 nm. Accordingly, samples without NH 4 I only exhibit two weak Eu 3+ emission peaks located at 598 and 619 nm, respectively. It can be ascribed to the reduction characteristic of I − ion. Furthermore, by partial replacement of Sr 2+ with Ca 2+ in Sr 4 Al 2 O 7 host, the emission intensity is enhanced up to 260% with emission peak red shifted by 5–10 nm. These results indicate that partial substitution of Sr 2+ by Ca 2+ is an efficient way to increase the proportion of longer wavelength emission and luminescence intensity for Sr 4 Al 2 O 7 :Eu phosphors.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2018
·
IF 2.32
Shuai Zhang,Hengwei Wei,Yang Zhou,Xiaoming Wang,Ling Xu,Huan Jiao
In this work, an airtight solid-state strategy was developed for the synthesis of K 2 TiF 6 :Mn 4+ phosphor without the usage of high concentration HF solution. By heating K 2 TiF 6 , K 2 MnF 6 and KHF 2 in a sealed container at 474 K for hours and then washing the as-synthesized samples several times, K 2 TiF 6 :Mn 4+ phosphor was obtained. The microstructure, luminescent properties of the phosphor were investigated systemically. The reaction mechanism were investigated and discussed in detail. KHF 2 is the key role to obtain the red phosphor, which provides additional pressure and HF gas atmosphere, works as reaction intermediate and contributes to Mn 4+ doping into K 2 TiF 6 host. By using as-prepared K 2 TiF 6 :Mn 4+ phosphor as a red componet for warm W-LEDs, the high color rendering index (Ra = 84) and low color temperature (CCT = 3621 K) device performance proved that this environmental friendly synthesis method would be an efficient way to produce red fluoride phosphor for W-LEDs.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2017
·
IF 3.833
Dingkun Zhang,Yongzan Zheng,Xiangnan Dou,Haifeng Lin,Syed Niaz Ali Shah,Jin-Ming Lin
Gas–solid phase reactions between ozone (O3) and three representative solids (alcohols, phenols, and saccharides) were investigated through a heterogeneous chemiluminescence (CL) strategy. When interactions between these two species occurred at the surface of the solid powder, an obvious CL effect was obtained. This performance could be attributed to the evolution of a ROOOH intermediate, which subsequently released emissive 1O2 species. This is the first report analyzing the gas–solid phase CL performance of O3 with alcohols, phenols, and saccharides. It is believed that this strategy can be extended to applications in other gas–solid phase CL analyses utilizing the O3 system. This has also created a novel area of gas–solid CL performance; thus, relevant processes and mechanisms can be deduced and identified.
研究领域:
化学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2015
·
IF 6.217
Jugong Zheng,Liang Ni,Yanwen Lu,Cancan Qin,Panxing Liu,Tongfu Wu,Yuefeng Tang,Yanfeng Chen
LiMnPO 4 is proposed as more promising cathode material as LiFePO 4 , while poor electronic conductivity and Jahn-Teller effects during charge/discharge processes hinder the electrochemical performance. To overcome these problems, one-step solid state reaction method is developed to synthesize LiMnPO 4 /C composites, which is with nanostructure , high crystallinity and good carbon coating. Manganese oxide sources and calcination temperature are investigated as factors for preparing high-performance LiMnPO 4 /C for Li-ion batteries. The results show that the LiMnPO 4 /C composites prepared with mixed manganese oxide deliver a superior initial capacity of 153 mAh g −1 at 0.05 C and high rate performance with discharge capacities of 123 mAh g −1 at 1 C and 103 mAh g −1 at 2 C. And the LiMnPO 4 /C composites synthesized at 600 °C can retain 94% of the initial capacity after 200 cycles at 1 C, revealing a stable cycling stability. Therefore, one-step solid state reaction brings to light the synthesis of high performance LiMnPO 4 /C cathode materials and is suitable for large scale production.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Optical Materials Express
·
2016
·Vol. 6
·期 2
·610-619
·
IF 2.657
Xianqiang Chen,Haiming Qin,Ye Zhang,Yongfu Liu,Jun Jiang,Haochuan Jiang
Transparent polycrystalline NdxGd3-xAl3Ga2O12 (Nd:GAGG) ceramics were prepared via solid-state reactive sintering from a mixture of commercial Gd2O3, Al2O3, Ga2O3, Nd2O3 and 0.05wt.% ZrO2 powders at 1650 °C. Fully dense ceramics were obtained for all samples with different Nd2O3 doping level. Uniform microstructures with average grain size of about 20 μm were observed in the ceramics, while no secondary phase was detected. Optimum transmittance of as high as 77% in near-infrared bands, which is close to its theoretical value of 81.1%, was achieved in the 0.8 at.% Nd:GAGG ceramics. The spectroscopic properties of the Nd:GAGG transparent ceramics were also investigated. Absorption cross-section of the 0.8 at.% Nd:GAGG ceramic at 808 nm is about 4.1 × 10−20 cm2. The emission cross-section at 1063 nm is about 1.8 × 10−19 cm2.
研究领域:
材料科学
·
光学工程
✓ 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）