EPL
·
2016
·Vol. 114
·期 5
·56003
·
IF 1.963
Lidong Dai,Lei Wu,Heping Li,Haiying Hu,Yukai Zhuang,Kaixiang Liu
In this study, the effect of pressure on undoped and 5% yttrium-doped SrZrO3 (SZY0 and SZY5) were conducted from the ambient condition to {\sim}25\ \text{GPa} with a diamond anvil cell. The comparison of the high-pressure Raman spectra of SZY0 and SZY5 indicate that SZY0 displays a rigid structure without any structural modification, whereas for SZY5 a structural transition at {\sim}15\ \text{GPa} is revealed. Some characteristic physical parameters such as bulk conductivities, grain boundary conductivities, Warburg diffusion coefficient, transference number and bulk relaxation frequency were determined by the high-pressure impedance spectroscopy data. An obvious discontinuous inflexion point (at {\sim}13\ \text{GPa}) for SZY5 sample is observable which was also verified the phase-transition of the Raman spectroscopy results. A mixed conduction mechanism for both SZY0 and SZY5 are coexisting for both SZY0 and SZY5 in a wide pressure range. The pressure-induced phase-transition of SZY5 would result in an inversion of conduction mechanism that is characterized by the dominant charge carriers transformation from electron to ion. The Maxwell-Wagner relaxation arising at the interfaces of grain and grain boundary indicates that Y-doping and pressure could make the ions diffusion much easier through the boundaries and finally enhance the dielectric performance of the sample. It is suggested that pressure could be a useful tool to manipulate the microstructure and dielectric performance of polycrystal through altering the grain boundary distribution.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2016
·Vol. 49
·期 34
·345102
·
IF 2.772
Lei Wu,LiDong Dai,HePing Li,YuKai Zhuang,KaiXiang Liu
Yttrium-doped BaZrO3 (BZY) is a promising electrolyte for intermediate-temperature protonic ceramic fuel cells. However, BZY exhibits a high resistance because of the blocking effect of the grain boundaries. In this study, the effect of pressure on undoped and 5% yttrium-doped BaZrO3 (BZY0 and BZY5) were investigated at 0.45–24.01 GPa and 273–673 K with a diamond anvil cell. Their bulk, grain boundary, and total electrical conductivities were determined by impedance spectroscopy and direct-current resistance measurement. Both samples tended to show increasing electrical conductivity with increasing pressure, although each showed a discontinuous inflexion point (at ~14.54 GPa for BZY0 and at ~11.11 GPa for BZY5) indicating a phase transition from a cubic to a tetragonal structure. The samples showed a 3.43 GPa difference in the onset pressure of the structure change. Characteristic parameters, including space charge potential, relaxation frequency, and transport activation energy, were obtained before and after the phase transition. The results suggest that pressure significantly improves oxygen ion conduction in acceptor-doped perovskites oxides.
研究领域:
材料科学
·
能源研究
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Le Fu,Bo Li,Guofu Xu,Jiwu Huang,Håkan Engqvist,Wei Xia
Thermal stability of nanocrystallites plays an important role in the manufacturing and application of nanocrystalline ceramics/glass-ceramics. This study explores the effects of thermal treatments on the microstructures of two ZrO 2 -SiO 2 nanocrystalline glass-ceramics (NCGCs), an undoped one and a yttria-doped one. The two as-sintered NCGCs were composed of tetragonal (t) and monoclinic (m) ZrO 2 nanocrystallites, and SiO 2 component was amorphous. t-ZrO 2 and m-ZrO 2 nanocrystallites were metastable during thermal treatment. The content of m-ZrO 2 in the undoped ZrO 2 -SiO 2 NCGC first increased after thermal treating at 850 °C for 5 h, then decreased after thermal treating at and above 950 °C. After thermal treating at 1250 °C for 5 h, t-ZrO 2 nanocrystallites experienced a rapid phase transformation during cooling, resulting the formation of 88.6 vol% m-ZrO 2 . Size-driven phase transformation was utilized to explain the metastability of t-ZrO 2 and m-ZrO 2 nanocrystallites. In contrast, the content of m-ZrO 2 in the yttria-doped ZrO 2 -SiO 2 NCGC continuously decreased with the increase of thermal treatment temperature. The addition of yttria improved the phase stability of t-ZrO 2 up to at least 1250 °C. Crystallite size of both t-ZrO 2 and m-ZrO 2 nanocrystallites increased with the increase of thermal treatment temperature in the two NCGCs. The presence of residual thermal stress in the as-sintered NCGCs changed the lattice spacing of t-ZrO 2 and m-ZrO 2 nanocrystallites, and the stress can be released after thermal treatment. Thermal treatment exerts significant influences on the microstructure of ZrO 2 -SiO 2 NCGCs.
研究领域:
材料科学
·
陶瓷学
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产品关联
DOI
高影响因子
JOURNAL OF PHYSICS-CONDENSED MATTER
·
2016
·Vol. 28
·期 47
·475501
·
IF 2.209
LiDong Dai,Lei Wu,HePing Li,HaiYing Hu,YuKai Zhuang,KaiXiang Liu
The electrical transport properties of undoped and yttrium-doped strontium titanate (Sr(Ti1 – xYx)O3 – δ, x = 0, 0.02) under high pressure were investigated with in situ impedance spectroscopy measurements. A pressure-induced conductivity switching for undoped and 2 mole% Y-doped strontium titanate is observed at around ~10.0 and 7.0 GPa respectively, which are caused by a cubic to tetragonal I4/mcm phase transition. The decrease of the phase transition point of 2 mole% Y-doped strontium titanate can be attributed to larger Y3+ atoms occupying the B-site and the creation of more oxygen vacancies, which lead to octahedra tilting and symmetry breaking. The results of the voltage-bias dependence of grain-boundary impedance of undoped and 2 mole% Y-doped strontium titanate at different pressures revealed that Schottky-type potential barriers formed at grain boundaries are the key factor for the accumulation of oxygen vacancy at the interface under pressure.
研究领域:
材料科学
·
凝聚态物理
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Erqing Zhao,Yudi Guo,Guangri Xu,Long Yuan,Jingcheng Liu,Xiaobo Li,Li Yang,Jingjing Ma,Yuanchao Li,Shumin Fan
Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 is regarded as one of the most promising solid electrolytes for all solid state lithium ion batteries (ASSLIBS). However, its grain boundary conductivity is still low, which reduces the total conductivity of electrolyte. In this work, in order to further improve the electrical conductivity of Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , a series of Y doped Li 1.3 Al 0.3-x Y x Ti 1.7 (PO 4 ) 3 (x = 0, 0.025, 0.05, 0.075 and 0.15) solid electrolytes were synthesized using a modified solid state method. Effects of Y doping content on morphology, phase and electrical conductivity of Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 electrolyte materials were systematically investigated. All synthetic electrolyte powders show Nasicon-like structure, well-shaped polyhedral morphology as well as good crystallinity. Y dopant content has a great influence on electrochemical properties of electrolytes. The high total conductivity of 7.8 × 10 −4 S/cm at room temperature and a low activation energy of 0.17 eV is obtained for the electrolyte with the Y doping content of 0.075 due to the increasing of grain boundary conductivity, and its electrical conductivity is about 2 times larger than that of the undoped electrolyte. The excellent electrochemical performance is mainly attributed to high electrolyte density which results from the good sintering property of electrolyte materials as well as the existence of YPO 4 phase at grain boundaries. Additionally, this electrolyte has a negligible electronic conductivity. These results suggest that Y doped Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 can be used as an alternative solid electrolyte for all solid state lithium ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2022
·
IF 4.865
Peng Liu,Xi Tan,Hao Ren,Wei Liu,Linwen Jiang,Xiaofeng Zhang
To improve the long-term oxidation resistance of SiC fibers, a novel yttrium-doped lanthanum monazite (Y-LaPO 4 ) coating was deposited onto the surface of SiC fibers (Y-LaPO 4 /SiC f ) by a simple hydrothermal method . The static oxidation behavior of Y-LaPO 4 /SiC f , SiC fibers coated with lanthanum monazite (LaPO 4 /SiC f ), and SiC fibers without coatings (SiC f ) was studied at 1350 °C for 50 h. The results indicated that yttrium diffused into the oxide scale during oxidation process. The thicknesses of the oxide scales for the oxidized fibers in Y-LaPO 4 /SiC f and LaPO 4 /SiC f were about 4.56 and 11.31 μm. SiC fibers without coatings were completely oxidized to silica . Furthermore, the oxidation kinetic curves of SiC f , LaPO 4 /SiC f , and Y-LaPO 4 /SiC f exhibited a parabolic trend during oxidation for 15, 20, and 50 h. Calculated the oxidation rate constants of SiC f , LaPO 4 /SiC f , and Y-LaPO 4 /SiC f were found to be 1.37, 1.08, and 0.40 μm 2 /h, respectively. The system of Y-LaPO 4 coatings not only retains LaPO 4 as a framework of the interface, but also incorporates yttrium to improve the oxidation resistance of fibers. Therefore, doping yttrium in lanthanum monazite can enhance the adherence between coatings and oxide scales and improve the oxidation resistance of SiC fibers.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 14
·4398-4406
·
IF 4
Hongyuan Song,Bin Liu,Jinhua Zeng,Guangpeng Huo,Liangwei Chen,Jianlu Wang,Lan Yu
The transition metal oxide (TMO) SrCoO3−δ family with rich structural diversity has been widely studied in the phase transition and energy application fields. We report the multiple-phase structure evolution, phase transitions during sintering, and electrical transport of A-site doped Sr4−xYxCo4O12−δ (x = 0–1.0) ceramics. Sr6Co5O15 (x = 0) adopts a hexagonal structure (H), Sr4−xYxCo4O12−δ (x = 0.2–0.4) ceramics adopts a cubic perovskite (CP) structure, and Sr4−xYxCo4O10.5+δ′ (x = 0.8–1.0) ceramics adopts an ordered-tetragonal (OT) structure; moreover, their phase transitions during the sintering processing of samples are systematically investigated. Combining the thermal analysis and X-ray diffraction results, the exothermic peak and weight gain of Sr3YCo4O10.5 (x = 1.0, T) at 1042 °C are considered to correspond to an ordered phase transition (T → OT) occurring. Finally, a systematic phase schema of the Sr4−xYxCo4O12−δ (x = 0–1.0) state dependence on the Y content and sintering temperature is obtained. The high-energy Y–O bond stabilizes the high-temperature CP structure (x = 0.2–0.4) and induces a structural evolution from the CP to OT structure (x = 0.8–1.0). In addition, all Sr4−xYxCo4O12−δ (x = 0–1.0) ceramics show semiconductive electrical transport behavior. Sr6Co5O15 (H) with a one-dimensional chain structure has the highest resistivity, while Sr3.8Y0.2Co4O12−δ (CP) with a three-dimensional corner-sharing structure exhibits the lowest resistivity, and Sr4−xYxCo4O12−δ (x = 0.2–1.0) ceramics show an increasing tendency in resistivity due to the hole carrier Co4+ converting to Co3+. We studied multiple-phase evolution and ordered phase transition in Sr4−xYxCo4O12−δ (x = 0–1.0) ceramics through Y–O bonding.
研究领域:
材料科学
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物理化学
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产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Shuang Gao,Zhenxing Wang,Yan Chen,Yimu Wang,Qiyuan Fu,Changhao Feng
The efficient and rapid detection of triethylamine (TEA) is crucial in the field of gas sensors. Sensors fabricated using doped ternary metal oxides demonstrate high response, good stability, excellent gas selectivity, and reproducibility. In this study, NiFe 2 O 4 nanofibers doped with different concentrations of Yttrium (Y/Ni = 0 at%, 1.5 at%, 2.5 at%, 3.5 at% and 4.5 at%) were synthesized via electrospinning, and gas sensors fabricated from these materials were systematically analyzed for their gas-sensing performances. The results indicated that the gas-sensing properties of Y-doped NiFe 2 O 4 nanofibers were improved. Gas sensors based on Yttrium-doped NiFe 2 O 4 nanofibers with a Y/Ni ratio of 2.5 % (referred to as 2.5 % Y-NFO) exhibited the best performance, exhibiting a gas response of 39.3 for the detection of triethylamine at a concentration of 100 ppm at 125 °C. This response was about 3.1 times higher than pure NiFe 2 O 4 nanofibers. Additionally, the response time of 2.5 % Y-NFO is only 2 s, which is much faster than other reported TEA sensors. In addition, these gas sensors exhibit excellent repeatability, selectivity, and humidity resistance. Finally, the underlying mechanism responsible for the enhanced gas-sensing properties is comprehensively discussed. This study presents a simple, stable, and effective route for synthesizing Y-NiFe 2 O 4 nanofibers, thereby achieving excellent sensing performance for TEA detection.
研究领域:
材料科学
·
传感器技术
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产品关联
DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-12
·
IF 15.7
Wang Shijie,Liang Kang,Zhao Hongshun,Wu Min,He Junfeng,Wei Peng,Ding Zhengping,Li Jianbin,Huang Xiaobing,Ren Yurong
High-capacity power battery can be attained through the elevation of the cut-off voltage for LiNi 0.83 Co 0.12 Mn 0.05 O 2 high-nickel material. Nevertheless, unstable lattice oxygen would be released during the lithium deep extraction. To solve the above issues, the electronic structure is reconstructed by substituting Li + ions with Y 3+ ions. The dopant within the Li layer could transfer electrons to the adjacent lattice oxygen. Subsequently, the accumulated electrons in the oxygen site are transferred to nickel of highly valence state under the action of the reduction coupling mechanism. The modified strategy suppresses the generation of oxygen defects by regulating the local electronic structure, but more importantly, it reduces the concentration of highly reactive Ni 4+ species during the charging state, thus avoiding the evolution of an unexpected phase transition. Strengthening the coupling strength between the lithium layers and transition metal layers finally realizes the fast-charging performance improvement and the cycling stability enhancement under high voltage.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2020
·Vol. 49
·期 8
·4945-4951
·
IF 1.774
Li Yan,Zhang Lin-Bin,Song Shuang,Lian Xiao-Xue
Au/Y-ZnO composite with excellent acetone sensing was successfully prepared by a facile wet chemical method. X-ray diffraction analysis, field-emission scanning microscopy, and transmission electron microscopy investigation revealed that the obtained Au/Y-ZnO was mainly composed of ZnO wurtzite phase and Au nanoparticles with a face-centered structure in diameter of 10 nm, and Y atom replaced Zn lattice sites to form yttria phase. Compared with the pure ZnO and Y-doped ZnO, the Au/Y-ZnO-based sensor shows significantly enhanced acetone gas sensing. Its response to 100 ppm acetone is 27.6, which is about 2.3 and 5.5 times that of the Y-ZnO and the pure ZnO, respectively. The Au/Y-ZnO-based sensor has a low detection limit (1 ppm), and fast response (3 s) and recovery (9 s). Au modification can obviously decrease the operating temperature (275°C). The enhanced gas-sensing of Au/Y-ZnO towards acetone can be ascribed to Y Zn and V
− Zn
defects, the Schottky barrier between Au nanoparticles and Y-doped ZnO, and the catalytic activity of the Au nanoparticles.
研究领域:
材料科学
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化学工程
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2024
·
IF 3.4
Renzhong Xue,Xiaosong Liu,Kun Yang,Tao Li,Haiyang Dai,Jing Chen
In this study, Na 1/3 Cd 1/3 (Bi 1-x Y x ) 1/3 Cu 3 Ti 4 O 12 (NCBYCTO, x = 0−0.20) ceramics were successfully prepared via solid state method. Their microstructure along with the optical, dielectric, and non-Ohmic properties were investigated systemically. It was shown that Y 3+ doping caused the decrease in cation vacancy concentration and the increase in optical energy band. With the increase of Y 3+ content, ceramics exhibited a more stable structure, while their average grain size increased from 6.80 μm to 9.12 μm and then decreased to 2.17 μm with the dopant amount. The relative density increased from 94.7 % for the undoped specimen to 95.6 % for the specimen with x = 0.20. The giant dielectric constant (ɛ′ = 44200) at a relatively low dielectric loss (tanδ = 0.048) at 10 kHz was obtained in the specimen with x = 0.08, being more than three times that of undoped sample and demonstrating the outstanding frequency stability in the range of 40−10 6 Hz. The giant dielectric constant below 10 6 Hz originated from Maxwell–Wagner relaxation related to the insulating grain boundaries (GBs) and followed the internal barrier layer capacitor model. Besides that, Y 3+ doping improved the nonlinearity properties of NCBYCTO ceramics. The specimen with x = 0.20 had the largest nonlinearity coefficient α (∼9.60) and breakdown field strength E b (∼7.15 kV/cm). At last, the nonlinear J-E characteristics were closely related to the GB conductivity activation energy.
研究领域:
材料科学
·
物理学
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产品关联
DOI
高影响因子
SENSORS
·
2025
·Vol. 25
·期 3
·901
·
IF 3.5
Jian Wang,Caicai Sun,Jusheng Bao,Zhiwei Yang,Jian Zhang,Xiao Huang
Simple SummaryIn this work, Y-doped LTO nanosheets were synthesized for NO2gas sensing under different humidity conditions. These materials showed increased responses at higher humidity levels due to enhanced proton conduction and NO2-assisted proton generation. Notably, Y-doped LTO nanosheets exhibited higher responses than pure LTO, as Y-doping created more oxygen vacancies, improving water adsorption and proton dissociation.Water molecules from the environment or human breath are one of the main factors affecting the accuracy, efficiency, and long-term stability of electronic gas sensors. In this contribution, yttrium (Y)-doped La2Ti2O7(LTO) nanosheets were synthesized by a hydrothermal reaction, demonstrating improved proton conductivity compared to their non-doped counterparts. The response of Y-doped LTO with the optimal doping concentration to 100 ppm NO2at 43% relative humidity (RH) was −21%, which is four times higher than that of bare La2Ti2O7. As the humidity level increased to 75%, the response of Y-doped LTO further increased to −64%. Unlike the gas doping effect observed in previous studies of semiconducting metal oxides, the sensing mechanism of Y-doped LTO nanosheets is based on the enhanced dissociation of H2O in the presence of target NO2molecules, leading to the generation of more protons for ion conduction. This also resulted in a greater resistance drop and thus a larger sensing response at elevated humidity levels. Our work demonstrates that proton-conductive oxide materials are promising gas-sensing materials under humid conditions.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
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