CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Zhengfei Xiang,Zhaoting Zeng,Tengfei Deng
In this study, 0.6Y 2 O 3 -0.4YCr 0.5 Mn 0.5 O 3 negative temperature coefficient (NTC) ceramics doped with different ZrO 2 contents were prepared using a two-step sintering method. The effects of Zr 4+ content on the microstructure and electrical properties of 0.6Y 2 O 3 -0.4YCr 0.5 Mn 0.5 O 3 were mainly investigated. For the microstructure, X-ray diffraction (XRD) reveals the presence of two main crystalline phases in the samples: Y 2 O 3 and YCr 0.5 Mn 0.5 O 3 . Scanning electron microscopy (SEM) reveals a clear two-phase appearance, and the porosity tends to decrease with the addition of ZrO 2 . Combined with energy dispersive spectrometer (EDS) to derive the distribution of the elements, Zr 4+ is mainly present in the Y 2 O 3 phase, with a small amount in the YCr 0.5 Mn 0.5 O 3 phase. In addition, the grain sizes of different groups were counted, and the grain size of Y 2 O 3 decreased from 2.73 ± 1.80 μm to 1.65 ± 0.93 μm with the increase of ZrO 2 content. For the electrical properties, the resistance-temperature curves were measured from 298.15 K to 1073.15 K, and all the samples exhibited NTC characteristics. And with the increase of ZrO 2 content, the resistivity increased from 1.91 × 10 7 Ω cm to 1.96 × 10 8 Ω cm, and the B 25/100 value decreased from 3315 K to 1310 K. In addition, the chemical state forms of the elements on the surface of the samples were analysed by X-ray photoelectron spectroscopy (XPS), and the valence states as well as the occupancy of the transition elements Cr and Mn were analysed in detail according to the principle of multiple splitting. Finally, the mechanism of influence on microstructure and electrical properties is explained by combining the theory of grain boundary migration and thermal ceramic conductivity.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2025
·
IF 5.5
Guobo Wu,Chao Yu,Shuangxi Gu,Hourui Cheng,Xu Cheng,Chengji Deng,Jun Ding,Zhenglong Liu,Zhoufu Wang,Hongxi Zhu
Al 4 O 4 C ceramics were prepared via pressureless sintering, and the effects of Y 2 O 3 content on their densification and mechanical properties were studied. When sintered at 1800 °C for 3 h, Al 4 O 4 C was identified as the major phase, while Y 3 Al 5 O 12 formed as a secondary phase. The in situ YAG effectively enhanced the densification of the ceramics and contributed to the improvement in their mechanical properties. The results indicate that the optimization of Y 2 O 3 content plays a crucial role in achieving favorable mechanical performance. Specifically, the bending strength peaked at 197.3 MPa with 3 wt% Y 2 O 3 , while the highest Vickers hardness and fracture toughness of 14.3 GPa and 2.6 MPa·m 1/2 were obtained with 5 wt% Y 2 O 3 . This study lays a foundation for the future research and application of Al 4 O 4 C ceramics.
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Wanying Wu,Mengmeng Lun,Zhifeng Xing,Hanzhao Song,Aihua Yao,Xunsheng Zhou,Zhong Wan,Kun-ming Gu,Sheng Yu,Qiliang Li,Yinzhen Wang,Wei Li,Guannan He,Benli Chu,Qinyu He
Te doped Yttrium-aluminum (Y 2 O 3 –Al 2 O 3 ) system powders were synthesized by solid-state method. The structure and optical properties were investigated by XRD , SEM, XPS and PL. XRD analysis indicated that the samples transform from YAM, YAP to YAG phase as the sintering temperature rises. The samples sintered below 1200 °C have a broad emission centered at 604 nm with a lifetime up to 13.33 μs under room temperature. While in the mix phase of YAP and YAG, a sharp and intense emission peak centered at 715 nm was monitored with a lifetime up to approximate 2.76 ms. Moreover, the band structure and density of states for Te doped YAGwere investigated by first-principle calculations.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Hao Zhou,Ziyan Zhao,Hui Zhang,Jinjing Yang,Anle Sun,Xuejian Liu,Zhengren Huang,Yan Liu
To expand the application of SiC/SiC joints under extreme conditions, Nano-Infiltration and Transient Eutectic (NITE) joining technology with AlN-Y 2 O 3 as a sintering additive was successfully developed. The rheological properties of the slurry and the microstructure evolution of the joints were systematically characterized by rheometer, SEM, EDS, EBSD , and TEM , respectively. Both room-temperature and high-temperature flexural strength was measured to evaluate the mechanical properties of the joints. An immersion test with concentrated nitric acids was performed to evaluate the corrosion resistance of the joints. The defect-free joining layer was composed of a dense α-SiC phase, a small amount of YAG(Y 3 Al 5 O 12 ) distributed in the triangular grain boundary, and a Y-Al-O glass phase from AlN-Y 2 O 3 . The mechanism of NITE joining could be attributed to the incoherent growth of the newly generated α-SiC in the joining layer along the α-SiC substrate. The maximum room-temperature strength of the joints was 320.5 ± 37.6 MPa. When the test temperatures were 1000 °C, 1200 °C, and 1400 °C, the flexural strength reached 238.7 ± 33.1 MPa, 215.5 ± 52.5 MPa, and 166.9 ± 52.0 MPa, respectively. After immersing the joints in a concentrated HNO 3 for 168 h, the flexural strength was 173.3 ± 12.6 MPa. The joints' excellent mechanical properties and corrosion resistance reveal great application potential under extreme conditions.
研究领域:
材料科学
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工程学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 12
·11005-11010
·
IF 2.195
Ma Qilu,Zhao Qing,Jia Xuemei,He Donglin,Chang Aimin
This paper had reported a new conception about the bilayer negative temperature coefficient (NTC) thermistors ceramics. To be specific, the ceramics were constituted by two layers, among which, the perovskite-structured LaMnO 3 was used to maintain the NTC properties of the material, while the LaMnO 3 –Y 2 O 3 composite ceramic was selected due to its resistance. The bilayer NTC thermistors were successfully fabricated according to the classical uniaxial pressing method in this study. After sintering at 1350 °C for 6 h, the two layers could well integrate with each other, without any cracks. Moreover, the values of ρ 500 , B 500/900 constant and activation energy of the NTC thermistors were within the ranges of 2.20 × 10 5 –1.46 × 10 8 Ω cm, 6293–11218 K, 0.543–0.968 eV, respectively. Such ceramics would be suitable for the high temperature application of NTC thermistors.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Chenguang Li,Chenbiao Lai,Yaoyan Wu,Hanxiang Ouyang,Junbin Sun,Weihong Lu
Alumina based rare earth oxides ceramic materials, with the good performance against the CMAS corrosion, were widely used as the thermal/environmental barrier coatings. In this work, three Y 2 O 3 –Al 2 O 3 binary ceramic bulks, which were the Y 3 Al 5 O 12 , YAlO 3 and Y 4 Al 2 O 9 , were prepared by high temperature solid state reaction using the Y 2 O 3 and Al 2 O 3 as the raw materials. The resistances to CMAS corrosion of these materials at 1250 °C and 1350 °C were compared fully. The compositions and structures of the samples before and after corrosion were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results showed that the different chemical compositions of the materials resulted in the different optical basicity (OB) values which can decide the reactivity of the material with the CMAS melts. The Y 3 Al 5 O 12 ceramic material was inert to the CMAS for its low OB value of 0.75 and damaged seriously by the CMAS through physical penetration. The YAlO 3 and Y 4 Al 2 O 9 with the high OB values of 0.80 and 0.87 reacted with the CMAS to form the Ca 4 Y 6 (SiO 4 ) 6 O. The YAlO 3 ceramic bulk exhibited the good performance against the CMAS corrosion benefitting from the formation of the Ca 4 Y 6 (SiO 4 ) 6 O and the CaAl 2 Si 2 O 8 .
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2026
·
IF 5.2
Abu Bakker Md Rahmatullah,Hongyu Zhu,Yi Cao,Baocang Zhou,Zhihua Zhao
Addressing the critical challenge of developing highly sensitive yet energy-efficient gas sensors for hazardous triethylamine (TEA) vapor, this research introduces a novel material design strategy through the strategic doping of yttrium oxide (Y 2 O 3 ) with neodymium (Nd 3+ ). We propose that the ionic radius mismatch of Nd 3+ effectively re-engineer the host lattice, enabling enhanced sensing performance at moderate operating temperatures. The synthesized Nd/Y 2 O 3 nanocomposites were systematically characterized, and the results confirm that Nd incorporation into the Y2O3 lattice promotes crystalline growth and significantly increases the concentration of oxygen vacancies, as evidenced by XRD, XPS, and BET analyses. This combined structural and chemical modification results in a chemiresistive sensor with outstanding performance, including a 17-fold enhancement in response to 100 ppm TEA at 200 °C compared to pristine Y 2 O 3 , along with rapid response-recovery kinetics, excellent selectivity, and reliable long-term stability. The enhanced sensing mechanism is attributed to a synergistic effect in which Nd-induced oxygen vacancies deepen the electron depletion layer, facilitate surface redox reactions, and the optimized nanostructure improves gas diffusion. This work validates Nd/Y 2 O 3 as a promising sensing material and demonstrates the rational rare-earth doping represents an effective strategy for advancing the performance of metal oxide gas sensors.
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DOI
高影响因子
CRYSTENGCOMM
·
2022
·Vol. 24
·期 43
·7669-7676
·
IF 3.756
Shengdi Ta,Huiting Zhang,Wenxia Wu,Yazhao Wang,Peng Zhang,Zeyu Cheng,Shoulei Xu,Bernard Albert Goodman,Wen Deng
The synthesis, structure, and optical properties are reported for a series of yttria-stabilized zirconia crystals in which some Y3+ was replaced by Eu3+. These crystals were grown by the optical floating zone (OFZ) method and were transparent without inclusions, cracks, or bubbles. They were all exclusively in the cubic phase, whereas the corresponding ceramic samples had a mixture of monoclinic and cubic phases. Absorption spectra showed a charge transfer band at 268 nm and a series of narrow peaks in the range 308–540 nm from Eu3+ f–f transitions. The crystals were efficiently excited at 393 nm, and exhibited excellent orange-red photoluminescence (PL) centred at 610 nm, from the 5D0 → 7F1 transition. The maximum PL intensity was observed with crystals prepared with 2.00 mol% Eu2O3, and compared with other rare earth ions; Eu3+-doped ZrO2–Y2O3 single crystals have a high concentration quenching threshold. The critical distance for Eu3+ ions was calculated as 11.8 Å, which indicates that multipole–multipole interactions dominate the non-radiative energy transfer between Eu3+ ions. Finally, the chromaticity coordinates (CIE) for all the samples were similar, and those for the (ZrO2)92(Y2O3)6(Eu2O3)2 crystal were (x = 0.6339, y = 0.3657) with a colour purity >98%.
研究领域:
材料科学
·
光学
·
晶体生长
·
发光材料
·
固体物理
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Wei-Ming Guo,Zhi-Lin Zhang,Jing-Xi Li,Yang You,Shang-hua Wu,Hua-Tay Lin
Al 2 O 3 –B 4 C ceramics had poor densification, due to the formation of Al 18 B 4 O 33 phase by reaction between Al 2 O 3 and B 2 O 3 on the surface of B 4 C. In the present work, Y 2 O 3 or Ti additive together with ZrO 2 from milling media were introduced into Al 2 O 3 –B 4 C ceramics. Results showed that Y 2 O 3 reacted with B 2 O 3 to produce YBO 3 phase, and removed Al 18 B 4 O 33 phase, resulting in the improved densification and the coarse microstructure. However, Ti and ZrO 2 reacted with B 2 O 3 to produce hard TiB 2 and ZrB 2 phases, removed the most of Al 18 B 4 O 33 phase, refined microstructure by pinning effect of hard particles, and improved densification and mechanical properties .
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 32
·11264-11271
·
IF 4.099
Mengxiao Li,Yu Feng,Qingyong Tian,Weijing Yao,Li Liu,Xuan Li,Huanjun Wang,Wei Wu
Advanced fluorescent materials have demonstrated great value in the anti-counterfeiting field for information storage and hiding. In this work, a novel strategy for producing UV light-switchable fluorescent patterns to hide and store information is proposed based on carbon dots (CDs) and Y2O3:Eu composites with exceptional optical properties. CDs can present blue emission under both 254 nm and 365 nm UV light excitation, but Y2O3:Eu can only arouse a red color under 254 nm light excitation. Under conventional 365 nm excitation, a single blue color and partial information are shown, however, the whole information in patterns can be displayed under specific 254 nm excitation. The functional anti-counterfeiting patterns are made by screen printing using as-prepared polyvinyl alcohol (PVA)-medium fluorescent inks. Moreover, the hidden information retained its integrity after printed patterns were exposed to an ambient environment for 90 days. Such invisible, tunable and ultra-stable fluorescent patterns utilizing 254 nm UV light well achieve information hiding and storage and increase information security for anti-counterfeiting applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Xingzhan Yuan,Shi Hong,Jing Wang,Bing Ma,Yifan Zhang,Man Niu,Laima Luo,Yucheng Wu
In this study, we propose a model to evaluate the ductile-to-brittle transition (DBT) of W based alloy using small tensile test and dislocation density measurement. The new model is built upon the high correlation between the DBT and the dislocation multiplication. Compared the measured results from the typical testing methods such as small tensile test, three-point bending test, it reveals that the new model is close to the bending test results. Interestingly, the equivalent transition temperature (ETT) of W-Y 2 O 3 alloy measured by three-point bending test and the new model is lower than that of pure W. The effect of grain boundary and Y 2 O 3 particles on DBT were discussed, and the lower transition temperature of W-Y 2 O 3 alloy is attributed to the easier dislocation multiplication near grain boundary as well as the increase of small angle grain boundary.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2016
·
IF 2.125
Qie Li,Zhihong Li,Dandan Feng,Tao Yang,Ying Li
The role of rare earth oxides (CeO 2 and Y 2 O 3 ) in the microstructures and properties of vitrified diamond composites was comprehensively investigated. The results revealed that the incorporation of appropriate amounts of CeO 2 or Y 2 O 3 could not only decrease the refractoriness but also increase the fluidity of vitrified bonds. In comparison with composites containing Y 2 O 3 , composites doped with CeO 2 possessed lower porosity and coefficient of thermal expansion . When adding 4 wt.% rare earth oxides, the flexural strength and thermal conductivity of composites containing CeO 2 simultaneously achieved the maximums, 102.5 MPa and 4.37 W·m − 1 ·k − 1 , respectively, which highly surpassed the values of composites without additives and composites containing Y 2 O 3 . In general, the difference of CeO 2 and Y 2 O 3 on properties of composites was mainly attributed to the different accumulation effects of corresponding cations. CeO 2 played greater impact than Y 2 O 3 on the properties of vitrified diamond composites.
研究领域:
材料科学
·
无机化学
✓ 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）