JOURNAL OF MATERIALS CHEMISTRY
·
2012
·Vol. 22
·期 31
·15887-15893
·
IF 5.968
Hongde Luo,Jie Liu,Xiao Zheng,Lixian Han,Kuaixia Ren,Xibin Yu
Trivalent ions B3+, Al3+ and Ga3+ have been introduced into Sr3SiO5:Ce3+ in this study. Among these ions, Al3+ and Ga3+ act as charge compensators and significantly enhance the maximum emission of Ce3+ by about 100% and 90%, respectively. Then, Al3+, Eu2+ co-doped Sr3SiO5:Ce3+ phosphors have been researched, which indicate that the emission spectra can be tuned from 530 to 575 nm by changing the concentration of Eu2+. The CIE chromaticity coordinates of the phosphors were calculated from (0.342, 0.518) to (0.442, 0.479). This indicates a potential for applications in daylight LEDs or warm-white LEDs.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Yue Leng,Shengde Dong,Zhan Chen,Yanxia Sun,Qi Xu,Luxiang Ma,Xin He,Chunxi Hai,Yuan Zhou
In this study, we addressed the poor cycling and rate performance of LiNiO2, a material with ultrahigh nickel content considered a strong contender for high-energy-density lithium-ion battery cathodes. We introduced nano-Al2O3 during the lithiation process to achieve dual modified material through bulk phase element doping and in situ LiAlO2 coating. Comparison revealed notable improvements in the modified materials. In particular, LiNi0.99Al0.01O2 maintained a capacity retention rate of 73.1% after 300 cycles in a long-cycle test at 0.5C current density, outperforming the undoped material. In rate performance tests, the doped samples consistently exhibited higher discharge-specific capacities than that of the undoped counterpart. Notably, at a high current density of 5C, LiNi0.99Al0.01O2 exhibited a discharge-specific capacity of 101.75 mAh g–1. The results indicate that an appropriate amount of Al doping can effectively stabilize the layered structure of the cathode material and delay the irreversible phase transition from H2 to H3. Further, Al doping facilitates the formation of a LiAlO2 coating on the surface of the particles. This coating acts as a fast-ion conductor, enhancing the transport of lithium ions and reducing the erosion of the active material by the electrolyte.
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 MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 24
·22375-22384
·
IF 2.22
Wang Li,He Lin,Li Ji,Yu Yongsheng,Li Haibo
M-type strontium ferrite is a kind of magnetic functional material with wide application prospect. In this work, SrFe 12− x Al x O 19 (0 ≤ x ≤ 1) and Sr 1− y Ca y Fe 8 Al 4 O 19 (0 ≤ y ≤ 0.4) have been prepared by a hydrothermal method, and the effects of Al 3+ doping and Al 3+ and Ca 2+ co-doping on the magnetic properties have been investigated. X-ray diffraction analysis indicates all the samples are a hexagonal structure, and the shift of the diffraction peaks suggests that Al 3+ and Ca 2+ are successfully doped in SrFe 12 O 19 . Field emission scanning electron microscope images show the particles have the hexagonal shape with the size of 1.1–2.9 µm. Vibrating sample magnetometer reveals that the doping of Al 3+ and the co-doping Al 3+ and Ca 2+ can enhance magnetic properties of strontium ferrite. For example, the values of coercivity and the saturation magnetization of SrFe 8 Al 4 O 19 are 914.1 Oe and 44.0 emu/g, which are 3% and 117% enhancement compared with SrFe 12 O 19 , respectively. For Sr 1− y Ca y Fe 8 Al 4 O 19 , coercivity and saturation magnetization increase from 914.1 Oe and 41.8 emu/g to 1047.2 Oe and 50.2 emu/g when the Ca 2+ doping concentration increases from 0 to 0.4. Moreover, the effects of acid washing also on phase composition, morphology and magnetism are researched. The as-synthesized doping strontium ferrite will be useful for the applications in security switching and recording media.
研究领域:
材料科学
·
磁学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2021
·Vol. 4
·期 3
·733-742
·
IF 5.693
Huang Jinping,Chen Qing,Chen Shuaifeng,Luo Lijie,Li Jianbao,Lin Chunfu,Chen Yongjun
FeNb 11 O 29 has a high theoretical capacity as a potential anode material for lithium-ion batteries; however, the practical capacity of FeNb 11 O 29 reported was unsatisfactory. In this study, a simple and efficient Al 3+ -doping technique was demonstrated to improve the electrochemical performance of FeNb 11 O 29 successfully. The influences of the Al 3+ doping amount were investigated. It was found that the crystal structure of FeNb 11 O 29 could be preserved when a suitable amount of Al 3+ was added, and that Al 0.2 Fe 0.8 Nb 11 O 29 demonstrated better electrochemical performance than FeNb 11 O 29 because the structure of Al 0.2 Fe 0.8 Nb 11 O 29 is more stable. At 0.1C, Al 0.2 Fe 0.8 Nb 11 O 29 possessed a high reversible capacity of 318 mAh g −1 with an initial-cycle Coulombic efficiency of 95.0%. Al 0.2 Fe 0.8 Nb 11 O 29 exhibited outstanding cycling stability with capacity retention of 92.9% at 10C over after 1000 cycles. Moreover, A LiFePO 4 /Al 0.2 Fe 0.8 Nb 11 O 29 full cell was prepared successfully with a discharge capacity of 206 mAh g −1 . The full cell exhibited good cycling stability showing the capacity retention of 84.2% over after 200 cycles at 1C and 89.8% over after 1000 cycles at 5C, respectively. This work suggests that Al 0.2 Fe 0.8 Nb 11 O 29 has great application prospects in lithium-ion batteries. Graphical abstract A suitable amount of Al 3+ doping in FeNb 11 O 29 significantly improves the electrochemical performance (especially the reversible capacity) of FeNb 11 O 29 .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Cheng Liu,Huiling Chen,Qi Chen,Jinhong Bi,Jimmy C. Yu,Ling Wu
A series of Al 3+ -doped UiO-66(Ce) MOFs (U(Ce x Al 1−x )) was developed to reveal the roles of metal doping on active site formation and substrate activation in photocatalytic selective transformation of amines to imines. Al 3+ doping induced crystal structure distortion to form coordinately unsaturated metal (Al, Ce) sites as Lewis acid sites to chemisorb and activate benzylamine (BA). In situ FTIR revealed that the Al site with stronger acid strength facilitated BA activation. The activation degree of N–H bonds in BA was evaluated by changes of calculated force constant. The intermediate products were confirmed through time-dependent in situ FTIR. The Al 3+ -doped sample U(Ce 0.90 Al 0.10 ), the optimal catalyst, showed a significantly increased BA conversion (97.6 %) than that (47.5 %) of undoped sample, which was attributed to enough active sites and the optimal charge mobility. Finally, the present study proposes a synergistic photocatalytic mechanism associated with molecular activation to demonstrate selective oxidation pathways at the molecular level.
研究领域:
材料科学
·
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Jing Yang,Yun Zhang,Xiaoning Li,Xinghua Zhu,Shihua Ding,Wenjie Zhou,Tianxiu Song
BaSi 2- x Al x O 5- x /2 ( x = 0-0.05) low-dielectric ceramics were prepared by the solid-phase method. The effects of heterovalent ion substitution on the crystal structure and microwave dielectric properties were studied. X-ray (XRD) diffraction revealed that they formed single-phase solid solution with orthorhombic structure. Appropriate amount of Al 3+ doping decreased the sintering temperature from 1225 °C to 1150 °C. The change in dielectric constant ( ε r ) resulted from the combined effects of the ionic nature of chemical bonds ( f i ave ) (internal factor) and the relative density (external factor). Si-O bonds contributed more significantly to the ceramic dielectric polarization. The increase in packing density and lattice energy ( U Total ) enhanced the quality factor ( Q×f ), which nearly tripled compared with the undoped case. The resonant frequency temperature coefficient ( τ ƒ ) was dominated by oxygen bond valence ( V o ). When sintered at 1150 °C for 4 h, BaSi 1.98 Al 0.02 O 4.99 exhibited optimal performance: ε r = 7.56, Q×f = 41,878 GHz, τ f = -17.65 ppm/°C. This study offered a new approach to modifying BaSi 2 O 5 ceramics.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ACTA MATERIALIA
·
2021
·
IF 8.203
Enbo Li,Wen Ma,Peng Zhang,Chennan Zhang,Yu Bai,Hongxia Liu,Shufang Yan,Hongying Dong,Xiangfeng Meng
A series of Al 3+ -doped SrZrO 3 perovskite powders with low infrared emissivity were prepared. The doping-effect of Al 3+ on infrared radiation ability and thermophysical properties was investigated in detail by theoretical and experimental methods. As a result, Al 3+ -doped SrZrO 3 perovskite's infrared emissivity is related to its electronic structure and particle morphology . It can be adjusted by the Al 3+ -doped concentration. The SrZr 0.86 Al 0.14 O 2.935 powder with stronger electronic conductivity and flake particles has the lowest infrared emissivity with 0.256 in 3-5 μm waveband at 590 °C and 0.383 in 8-14 μm waveband at 550 °C. Al 3+ -doped SrZrO 3 perovskites still maintain ideal thermal stability and low thermal conductivity above 800 °C. Base on both low infrared emissivity and thermal conductivity, Al 3+ -doped SrZrO 3 tablets exhibited weaker thermal radiation intensity in the high-temperature condition and might be the potential low thermal infrared materials servicing under extreme temperature in the future.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2024
·
IF 2.5
Xiaogang Yu,Md Mostafezur Rahman,Renpeng Yang,Chengwei Wu,Abdelhakim Bouyahya,Wei Zhang
Magnetic induction hyperthermia with self-regulated temperature is an advanced technology capable of automatically regulating hyperthermia temperature through a magnetic phase transition, which has a promising application prospect. This paper investigated the effects of Al 3+ doping on the magnetic properties and Curie temperature of Zn-Mn ferrite. The specific saturation magnetization and Curie temperatures of Zn 0.5 Mn 0.5 Al x Fe 2-x O 4 (0 ≤ x ≤ 0.6) nanoparticles decrease linearly with increment of Al 3+ content. The magnetic heating experiments exhibit that the synthesized nanoparticles can raise the temperature of agar phantom to above 42 °C and self-regulate the temperature below their Curie temperatures, demonstrating their potential for self-regulated temperature hyperthermia. Additionally, in vitro cell experiments confirm the nanoparticles’ good biocompatibility.
研究领域:
材料科学
·
生物医学工程
·
纳米医学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Advanced Ceramics
·
2022
·Vol. 11
·期 5
·742-753
·
IF 11.534
Guo Meng,Liu Yufeng,Zhang Fengnian,Cheng Fuhao,Cheng Chufei,Miao Yang,Gao Feng,Yu Jun
A series of high-entropy perovskite oxides (HEPOs) La(CoCrFeMnNiAl x ) 1/(5+ x ) O 3− δ ( x = 0.4, 0.5, 0.6, and 0.7) have been synthesized by coprecipitation method combined with calcination process and explored as electrodes for supercapacitors. The crystal structure, microstructure, and elemental composition of HEPOs were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS) in detail. The electrochemical properties of HEPOs as supercapacitor electrodes were elucidated. The specific capacitances of HEPOs ( x = 0.4, 0.5, 0.6, and 0.7) are 281.84, 353.65, 325.60, and 259.30 F/g at the current density of 1 A/g, respectively. After 2000 cycles, the specific capacitances of HEPOs ( x = 0.4, 0.5, 0.6, and 0.7) remain 85.01%, 88.61%, 86.37%, and 91.25%, respectively. Such outstanding electrochemical properties can be attributed to the entropy-stabilized structure caused by mixed six cations in B-site and the Al 3+ -doping suppressing active ion aggregation during charge—discharge process. This research highlights the potential of HEPOs as electrodes for supercapacitors.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
INTEGRATED FERROELECTRICS
·
2023
·
IF 0.7
Kang-Qiang Liu,Chuan-Bao Wu,Si-Yu Zhou
ABSRACTFor achieving a uniform and stable suspension of CeO2 nanoparticles in aqueous medium, Al3+ was doped into the lattice of CeO2 by hydrothermal treatment. Although the doping will increase the probability of adhesion of primary particles with the size of 7 nm, it can effectively prevent the agglomeration between CeO2 particles, greatly improve the dispersion uniformity and suspension stability of particles, greatly narrow the particle size distribution of secondary particles, and make the degree of particle agglomeration controllable. Meantime, the UV absorption property of the product was improved and the absorption peak was red shifted after Al3+ doping.
研究领域:
材料科学
·
纳米技术
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2021
·Vol. 97
·期 3
·663-671
·
IF 2.326
Wang Yongqiang,Zhou Jin,Shi Chenfei,Gong Gaoshang,Hu Huiyun,Su Yuling
Previous reports depict that the nonstoichiometric Co/Mn ratio greatly affects the physical properties of Ca 3 CoMnO 6 , but few papers focus on the Co/Mn site doping effect. In order to investigate the influence of the substitution on the magnetization, partial Mn 4+ ions were replaced with Al 3+ ions and polycrystalline Ca 3 CoMn 1- x Al x O 6 ( x = 0, 0.05, 0.1, 0.15, 0.2) samples were prepared. All the samples crystallized into rhombohedral structure without existence of impurities. SEM patterns showed that the mean particle size decreased with the introduction of Al element. Due to the dilution effect of nonmagnetic Al 3+ ions to the spin chains, the competing short-range antiferromagnetic/ferromagnetic order caused by the “order by disorder” phenomenon was suppressed. The high-temperature spin freezing peak disappeared gradually and the doped samples presented a faster dynamic behavior, indicating a more robust long-range antiferromagnetic order. The time-dependent magnetization showed a nonmonotonic relaxation in a field of 5T, implying the possible existence of quantum tunneling of magnetization.
Ca 3 CoMn 1- x Al x O 6 ( x = 0, 0.05, 0.1, 0.15, 0.2) samples were synthesized and all of them crystallized into single-phase rhombohedral structure. Due to the dilution effect of the nonmagnetic Al 3+ ions to the …Co 2+ -Mn 4+ -Co 2+ -Mn 4+ …spin chains, the high-temperature spin freezing peak disappears gradually and a faster dynamic behavior in the doped samples is observed. Our investigation confirms that the substitution of the nonmagnetic Al 3+ ions has a similar effect with the Co/Mn defection. This is to say that the nonmagnetic doping could also suppress the formation of short-range magnetic correlation and help in building a more robust long-range antiferromagnetic order. For the nonmonotonic relaxation of the time-dependent magnetization, it implies the possible existence of quantum tunneling of magnetization. The normalized time-dependent M/M 0 curves for Ca 3 CoMn 1- x Al x O 6 ( x = 0, 0.05, 0.1, 0.15, 0.2) measured at 5 K. (1) The magnetization was measured by cooling the samples down to 5K, a field of 5T was applied and kept for 10 min, switching off the field and the remanent magnetization was recorded. (2) The magnetization was measured by cooling the samples down to 5 K firstly and the magnetic field was switched on, as well as field reaches 5T the magnetization was recorded immediately.
研究领域:
凝聚态物理
·
磁性材料
·
强关联电子系统
·
低温物理
·
自旋链
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Weijia Guo,Peiyao Zhao,Zhenxing Yue
Passive electronic components made from dielectric ceramics can hardly operate at extremely high temperatures, which is attributed to the sharply increasing dielectric loss and leakage conductance. In this work, the widely applicated CaTiO 3 ceramics are used as the matrix, and the high-temperature electrical properties are modified by doping Sm 3+ and Al 3+ . The Sm-doping in CaTiO 3 ceramics can significantly suppress the dielectric relaxation at low frequencies and reduce the high-temperature leakage conductance. Continued doping of Al in Ca 0.6 Sm 0.27 TiO 3 ceramics can further reduce the high-temperature dielectric loss and conductivity. These changes are associated with tighter crystal structures and fewer defects in the ceramics. With Sm and Al doping, the high-temperature dc conductivity of the ceramics is reduced by about 4 orders of magnitude, and a dielectric loss of less than 0.02 and a low temperature cofficient of capacitance (TCC) of − 25 ppm/℃ are obtained over a wide temperature range of room temperature to 530 ℃. Outstanding temperature stabilities are exhibited over a temperature range of 25 ∼ 200 ℃ in energy storage performance and charge-discharge property. Extremely fast discharge speed ( t 0.9 = 16 ns) makes it suitable for pulsed power electronic systems. Such linear dielectric materials are expected to be used in harsh environment of high temperatures.
研究领域:
材料科学
·
电气工程
·
陶瓷
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）