JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 8
·7582-7589
·
IF 2.195
Xu Yuan,Zhang Kaituo,Fu Lei,Tong Ting,Cao Le,Zhang Qifeng,Chen Ligui
MgO addition Ba(Zr 0.15 Ti 0.85 )O 3 (BZT) ceramics was prepared using conventional solid state reaction method and effect the MgO content in BZT ceramics on their sintering temperature, microscopic appearance, dielectric properties and ferroelectric properties was investigated. The result is that the addition of MgO can greatly reduce the sintering temperature of BZT ceramics. The average grain size can be gradually reduced as the concentration of MgO increases. The lattice constant is reduced by Mg 2+ entering the crystal structure instead of Ti 4+ or Zr 4+ . BZT ceramics exhibit excellent dielectric properties when a small amount of MgO was added. The maximum dielectric constant moves to the low temperature region when MgO content was increases. The hysteresis loop becomes thinner and the coercive field was significantly reduced.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·Vol. 12
·期 25
·9236-9246
·
IF 5.7
Bo You,Bin Lu,Dazhen Wu,Ruijie Pei
MgO was found to be a good sintering aid for densification of several types of ceramics; however, the previous reports seldom provided persuasive evidence to support their proposed functional mechanism. In the present work, we successfully fabricated polycrystalline transparent In2O3 semiconductor ceramics using MgO as an additive and offered vital insight into the additive roles in sintering behavior and optical properties, which are conducive to mastering the microstructure evolution principle and interaction function mechanism. The oxygen defect and solute drag mechanisms have combined effects on the sintering of MgO-doped In2O3 ceramics. Additionally, MgO also helps to improve the thermal stability. At the optimized MgO content of 0.5 at%, the In2O3 ceramic sintered at 1600 °C under an oxygen atmosphere achieves an in-line transmittance of 63.0% at 633 nm (∼83% of the theoretical transmittance of a perfect In2O3 single crystal) with a fine average grain size of ∼9.7 μm. Upon deep UV excitation, the transparent In2O3 semiconductors exhibit broad spectral bands covering from the near-UV to the entire visible region, where the dominant ∼493 nm cyan light derives from the deep-level defect emission. The MgO dopants enhance the photoluminescence intensity and prolong the deep-level fluorescence lifetime. The cathodoluminescence spectra show broad orange emission, with the emission centers located at 626 and 613 nm for the intra-grain and grain-boundary regions, respectively. The integral intensity of cathodoluminescence increases as the acceleration voltage increases, while the intensity in the grain interior is much higher than that on the grain boundary at each voltage.
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
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Zitao Shi,Zixuan Fang,Shuren Zhang,Bin Tang
Monoclinic Sm 2 O 3 ceramics were prepared using the conventional solid-state sintering method. The influences of sintering temperature on structure, morphology, and performance of Sm 2 O 3 ceramics were studied systematically. The excellent microwave dielectric properties ( ε r = 21.95, Q × f = 47,000 GHz, and τ f = +30.15 ppm/°C) were achieved in Sm 2 O 3 ceramic sintered at 1550 °C for 4 h. Interestingly, varying degrees of cracking were observed after the sintered samples were placed for a short time, with the extent depending on the sintering temperatures. The reasons for cracking were analyzed through chemical bond characteristics and microstructure. The analysis of bond valence and microstructure revealed that Sm 2 O 3 ceramics sintered at higher temperatures exhibited larger bond strain index, global instability index, and interplanar spacings. These results suggest that the cracking of Sm 2 O 3 ceramics originates from inner stress resulting from structural variations caused by variations in sintering temperatures. The effect of MgO addition on microwave dielectric properties and stability of Sm 2 O 3 ceramics was also investigated. Phase identification and elemental distribution indicated that MgO existed as a secondary phase. The Sm 2 O 3 ceramic with 20 wt% MgO addition exhibited optimal microwave dielectric properties: ε r = 17.72, Q × f = 61,100 GHz, and τ f = +2.4 ppm/°C. Importantly, cracking was not observed when MgO addition amounts were 5 wt% or higher. The attractive microwave dielectric properties and favorable stability confirm the possibility of the 5G applications for Sm 2 O 3 /MgO composite ceramics.
研究领域:
材料科学
·
电子材料
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·
IF 3.8
Shuo Yan,Yuhong Chen,Ziqiang Yin,Binwei Huang,Quanxing Ren,Tihao Cao,Xuxin Ping,Ruibin Liu,Zhengren Huang,Qing Huang,Yinsheng Li
SiC ceramics were fabricated by spark plasma sintering of β-SiC powder with various rare-earth (RE = La, Gd, Yb, Sc) oxides and magnesia additives. The phase compositions, microstructures, lattice oxygen contents, and thermal conductivities were systematically investigated. A decrease in the cationic radius of rare-earth element resulted in an increased cationic field strength. This enhanced attraction to oxygen anion led to higher viscosity and improved high-temperature stability of the intergranular RE-Mg-Si-O liquid phase. After sintering at 1850°C, influenced by liquid-phase viscosity, the degree of β→α phase transformation in SiC and the grain size decreased with decreasing cationic radius of rare-earth element. After sintering at 2050°C, the liquid-phase viscosity significantly decreased, but volatilization became pronounced. The extent of β→α phase transformation and the grain size were affected by both liquid-phase viscosity and volatility. Larger grain size and higher affinity of rare-earth cations for oxygen anions contributed to reduce lattice oxygen content. The thermal conductivities of the SiC ceramics ranged from 192 to 229 W/mK. Notably, the SiC ceramic with Yb 2 O 3 -MgO additives exhibited the largest grain size, the lowest lattice oxygen content, and the elimination of β/α heterophase boundaries, thereby achieving the highest thermal conductivity of 229 W/mK.
研究领域:
材料科学
·
热传导工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Yongzhi Luo,Bin Wang,Xi Zhang,Bin Kang,Jianguo Deng,Shengquan Yu
Nd:Y 2 O 3 transparent ceramics were fabricated by vacuum pre-sintering and post-hot isostatic pressing with ZrO 2 and MgO as sintering additives. It was found that binary additives not only promoted the densification of Y 2 O 3 ceramics, but also decreased the pre-sintering temperature by at least 150 °C compared with the single addition of ZrO 2 . The best quality sample with 1 at.% ZrO 2 and 0.06 at.% MgO was pre-sintered at 1550 °C and post-HIPed at 1500 °C. The average grain size was approximately 0.96 μm, and the in-line transmittance reached 75.9 % at 400 nm and 81.4 % at 1000 nm. The ceramic also exhibits good optical homogeneity, which is evaluated by the interference stripes with the PV and RMS values of 385.8 nm and 21.3 nm, respectively. Continuous wave laser operation of the sample was demonstrated, and a maximum output power of 1.73 W at 1080.4 nm was achieved with a slope efficiency of 11.3 %.
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
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Hongyu Liang,Shijing Zou,Manqiang Liu,Tianqiang Yin,Xiaojie Xia,Xijun Hua,Yonghong Fu,Yongfeng Bu
The low concentration of water-based lubricants and the high chemical inertness of the additives involved are often regarded as basic norms in the design of liquid lubricants. Herein, a novel liquid superlubricant of an aqueous solution containing a relatively high concentration of salt, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), is reported for the first time, and the superlubricity stability and load-bearing capacity of the optimized system (MgO0.10/LiTFSI10) are effectively strengthened by the addition of only trace (0.10 wt %) water–chemically active MgO additives. It demonstrates higher applicable loads, lower COF (∼0.004), and stability relative to the base solution. Only a trace amount of MgO additive is needed for the superlubricity, which makes up for the cost and environmental deficiencies of LiTFSI10. The weak interaction region between free water and the outer-layer water of Li+ hydration shells becomes a possible ultralow shear resistance sliding interface; the Mg(OH)2 layer, generated by the reaction of MgO with water, further creates additional weakly interacting interfaces, leading to the formation of an asymmetric contact between the clusters/particles within the hydrodynamic film by moderating the competition between interfacial water and free water, thus achieving high load-bearing macroscopic superlubricity. This study deepens the contribution of electrolyte concentration to ionic hydration and superlubricity due to the low shear slip layer formed by interfacial water competition with water-activated solid additives, providing new insights into the next generation of high load-bearing water-based liquid superlubricity systems.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Canglong Wang,Zhaocang Meng,Jianke Tian,Yiwen Liu,Yafeng Shu,Haibo Wu,Lei Yang
Given the wide prospects for SiC ceramic with high thermal conductivity, high-throughput screening of SiC containing BeO-Y 2 O 3 -Al 2 O 3 -MgO additives has been implemented by the experimental and multiscale simulation investigation. About 16 groups of SiC prepared by SPS are composed of 4H-SiC, 6H-SiC, 3C-SiC, BeO and yttrium aluminum garnet phases, and exhibit equiaxed and columnar microstructures. It was verified by the density functional theory simulation that these dopants (Be, O, Mg, Al and Y) can migrate spontaneously towards the Σ13 (150) [001] GB. The ceramics with thermal conductivity higher than 120 W/(m·K) were screened out. Especially, the annealed SiC with 5%BeO-10 % additive exhibits the maximum thermal conductivity of 206.5 W/(m·K). The Vickers hardness about 16.89 GPa can be predicted by the macro finite element model simulation, which is accorded with the experimental result. This work provides an economically feasible project for the large-scale production of SiC ceramics with high thermal conductivity.
研究领域:
材料科学
·
计算材料学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Ge Yang,Xi Yan,Yan Chen,Xiao-Jing Guo,Wan-Zhong Lang,Ya-Jun Guo
In recent years, Ga-based catalysts attract much attention in propane dehydrogenation (PDH) reaction due to environmental friendliness and low cost. Nevertheless, it is still challenging to obtain high selectivity of propylene under harsh reaction conditions. In this work, the supported catalysts (Ga- x Mg/ZSM-5) were prepared with the sequential impregnation method and applied in the PDH reaction. The results show that MgO as an additive reduces the acidity of the catalysts, promotes the dispersion of Ga 2 O 3 and improves the selectivity of propylene. As a result, the average particle size of the Ga/ZSM-5 catalyst is larger (4.5 nm), and the initial propylene selectivity is only 71.0 %. In contrast, the optimal Ga-0.7Mg/ZSM-5 catalyst shows the smallest particle size (2.4 nm) and the highest propylene selectivity of 90.8 %. In comparison with the previous GaO x catalysts in literatures, the Ga-0.7Mg/ZSM-5 catalyst exhibits a superior production rate of propylene ( r C 3 H 6 ) based on either catalyst weight or Ga 2 O 3 weight.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yilin Zhao,Shenghua Liu,Xiaoqian Feng,Jiaxin Wang,Lijiao Chen,Yonghua Zhao,Huan Wang,Qijian Zhang
Dry reforming of methane (DRM) is a promising pathway to convert greenhouse gas into syngas. However, the commonly used Ni based catalysts suffer deactivation due to severe sintering and coking. In this paper, a series of porous Ni/MgO-ZrO 2 catalysts (5Ni/xM(1-x)Z, x = 0, 20, 40, 60, 80 wt%, respectively) with high specific surface area were synthesized by a facile combustion method followed by incipient impregnation. It is found that the appropriate amount of MgO (40 %) addition in ZrO 2 favors high porosity and high specific area. More MgO enhances the basicity of the catalyst as well as the metal-support interaction (MSI) by the formation of NiO-MgO solid solution, thus improving DRM activity and coking resistance. However, excessive MgO addition leads to over-strong MSI and lower porosity, resulting in lower DRM activity. The catalyst with 40 % MgO addition (5Ni/40M60Z) exhibits the best activity (conversions of CH 4 ∼ 76 %, CO 2 ∼ 83 %) and stability (>50 h) at high GHSV = 96000 ml/g cat ·h and 750 °C. in situ DRIFTS reveals the mechanism that MgO addition improves DRM activity and stability. Compared with ZrO 2 where CO 2 adsorbs as monodentate carbonate, CO 2 tends to adsorb on 40 %MgO-60 %ZrO 2 as bidentate carbonate and then easily transfer to more stable intermediate bidentate formate, thus improving DRM activity and coking resistance. This study provides new insights on the role of Mg addition in Ni/MgO-ZrO 2 DRM catalysts.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Yi-Ning He,Ren-Zhong Zhang,Jia-Min Wu,Ze-Yu Deng,Ze-Yuan Li,Jia-Xin Zheng,Lin Guo,Zhi-Xiang Cai,Yu-sheng Shi
SiO 2 -based ceramics are an ideal material for manufacturing radomes due to their thermal stability, high dielectric properties, and simple processing techniques. However, traditional manufacturing methods heavily rely on molds, making it difficult to form complex SiO 2 -based ceramic structures. Digital Light Processing (DLP) technology was applied to fabricate SiO 2 -based ceramics doped with Al 2 O 3 -MgO in this work. The influence of the Al 2 O 3 -MgO content on the SiO 2 -based ceramics was systematically investigated. Increasing Al 2 O 3 -MgO content causes a shrinkage to first decrease then increase, contrasting with the flexural strength's initial increase and subsequent decrease. The main reason is magnesium-aluminum spinel (MgAl 2 O 4 ) generated during the sintering process and thus retards crack propagation, promoting a transition in fracture mode. During the fracture stage, the fracture mode of samples with 10.0 wt% Al 2 O 3 -MgO is mainly transgranular fracture, instead of intergranular. This transition in fracture mode enhanced the flexural strength. Meanwhile, as the Al 2 O 3 -MgO content continues to increase, excessive spinel causes agglomeration within the ceramic microstructure. When the Al 2 O 3 -MgO content reached 10.0 wt%, the shrinkage decreases to a minimum of 3.32 %, and the flexural strength increases to a maximum of 15.94 MPa, making it suitable for manufacturing ceramic radomes. The research results provide a new solution for manufacturing SiO 2 -based ceramic radomes by DLP.
研究领域:
陶瓷材料
·
增材制造
·
材料科学
·
材料电学性能
·
微观结构调控
✓ 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）