JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 20
·1-15
·
IF 2.8
Xie Zhuojia,Jiang Xinyu,Zhang Weijian,Zou Zhengguang
With the development of the current times, the demand for refrigeration is in every aspect. Nevertheless, the necessity for new refrigeration materials is immediate because of the greenhouse effect and the destruction of the atmosphere. Therefore, perovskite materials have been investigated. La 0.8− x Eu x Ca 0.1 Sr 0.1 MnO 3 (LECSMO) ( x = 0.05, 0.10, 0.15) powder samples were prepared using the sol–gel method (S–G). The structure, magnetocaloric effect, and magnetic of LECSMO have been explored. X-ray diffraction (XRD) indicates that all samples belong to the rhombohedral perovskite structure of the Pbnm space group. The magnetic research of LECSMO revealed that the samples doped with Eu 3+ exhibited a ferromagnetic (FM) to paramagnetic (PM) transition around the Curie temperature (Tc). As the amount of Eu 3+ doping is added, Tc decreased from 264 to 194 K. Normalization and Banerjee’s criterion confirmed the second-order phase transition of the LECSMO near Tc. The maximum magnetic entropy change ( \(-\varDelta {S}_{M}^{max}\) ) for LECSMO ( x = 0.05, 0.10, 0.15) is 5.39, 4.52, and 4.35 J/(kg·K) when the applied magnetic field (H) = 5 T, respectively. Further, the relative cooling power (RCP) of LECSMO is 282.20 J·kg − 1 , 305.20 J·kg − 1 , and 323.15 J·kg − 1 , respectively.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Chemosensors
·
2022
·Vol. 10
·期 12
·527
·
IF 4.229
Anheng Gu,Guo-Hui Pan,Huajun Wu,Liangliang Zhang,Ligong Zhang,Hao Wu,Jiahua Zhang
Orthorhombic ZrTiO4is an attractive dielectric material; its optical properties are, however, less known. In this paper, we reported on the microstructure and luminescence studies of pristine ZrTiO4and Eu3+-doped ZrTiO4phosphors. The results indicated that two types of TiO6octahedra, the isolated/ localized and coupled/delocalized, coexisted in host matrix. Eu3+doping could induce oxygen vacancy defect states located below the bottom of the conduction band. Pristine ZrTiO4showed bright yellow luminescence via STEs recombination at defects sites at low temperatures, but significant thermal quenching occurred due to STEs migration to quenching centers at elevated temperatures. Effective host sensitized energy transfer to Eu3+was observed in ZrTiO4:Eu3+phosphors and yielded the red characteristic emissions of Eu3+. Anomalous STEs luminescence enhancement and spectral blue-shift in the excitation spectra with higher Eu3 +concentration appeared and were explained by considering three factors: competitive absorption between electron transitions from the top of the valence band to the defect states and host conduction band, Eu3+doping driving the production of more isolated TiO6octahedra, and energy back-transfer from Eu3+activators to other titanate groups. On the basis of the dual-emitting combination strategy involving host STEs and Eu3+luminescence, ZrTiO4:Eu3+phosphors were demonstrated to be ratiometric self-referencing optical thermometric materials, with a working range of 153–313 K and a maxima of relative sensitivity to ~1.1% K−1at 243 K.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
OPTIK
·
2020
·
IF 2.187
Mingjing Bian,Hongyan Zhang,Jun Zhang,Zhijun Li
The influence of post-annealing on optical properties of Eu-doped ZnO (ZnO:Eu 3+ ) microsphere synthesized by hydrothermal method has been studied. The intrinsic deep defect emission of ZnO and the transition emission of both 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 related to Eu 3+ have been observed under excitation at 325 nm. The photoluminescence (PL) spectra reveal that ZnO annealed in N 2 is more favorable for Eu 3+ being doped into ZnO, which is helpful to greatly enhance the red light emission of ZnO:Eu 3+ . Alkaline conditions are more conducive to the formation of intrinsic deep defects in ZnO lattice, but they are not so conducive to the doping of Eu 3+ ions into ZnO lattice. From Gaussian deconvolution analysis of PL spectrum for ZnO:Eu 3+ , it can be seen that intrinsic defects of ZnO in N 2 atmosphere may efficiently assist energy transfer from ZnO host to Eu 3+ ions to enhance Eu 3+ intrinsic red light emission. There are blue light (446 nm), green light (525 nm) and stronger red light (618 nm) which are simultaneously obtained. This work could pave a way for high performance of white light emission application.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Corrosion Communications
·
2023
·
IF 0
Xiaoping Lai,Jie Wang,Xin Wang,Kuo Jiang,Weizhi Tian,Baowen Xu
YSZ:Eu powder was prepared by sol spray pyrolysis method. Thermal barrier coatings (TBCs) composed of Eu 3+ -doped pure tetragonal yttrium-stabilized zirconia (namely, YSZ:Eu) were fabricated by air-plasma spraying technique. Crystal structure and fluorescence intensity of YSZ:Eu coating were investigated after aging at 1200 °C for 5 − 100 h. X-ray diffraction (XRD) indicates that tetragonal phase in YSZ:Eu coating had high resistance to degradation over a wide range of time periods and temperatures. Luminescence results indicate that asymmetry ratios of the fluorescence emission spectra were stable in a range of 1.2 ± 0.2. Relationships between phase structure and lattice distortion were further studied by fluorescence spectroscopy measurement using I 606 / I 590 intensity ratio. The fluorescence results were consistent with those drawn by XRD, where the high stability of YSZ:Eu coating was confirmed. Excellent thermal stability, in terms of both the phase structure and luminescence intensity, of YSZ:Eu coating indicates that the present preparation method is suitable for phosphor powder applications.
研究领域:
材料科学
·
无机化学
·
光学
✓ 已验证
DOI
SOLID STATE SCIENCES
·
2016
·
IF 2.041
Yinyan Li,Shiqing Xu
Uniform and well-defined Lu 2 O 3 and Lu 2 O 3 :Eu 3+ microarchitectures have been successfully synthesized via a green and facile ionic liquid-based hydrothermal method followed by a subsequent calcination process. Novel 3D micro-rodbundles and 1D microrods of Lu 2 O 3 and Lu 2 O 3 :Eu 3+ were controllably obtained through this method. X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and photoluminescence spectra were used to characterize the micromaterials. The proposed formation mechanisms have been investigated on the basis of a series of SEM studies of the products obtained at different hydrothermal durations. The results indicated that hydrothermal temperature and the ionic liquid-tetrabutylammonium hydroxide were two key factors for the formation as well as the morphology control of the Lu 2 O 3 and Lu 2 O 3 :Eu 3+ microarchitectures.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Ying Ji,Xiaoyang Liu,Benxian Li,Jingchao Zhang,Xiaofeng Wang
Mild molten salt synthesis (MSS) method was utilized to synthesize rare earth fluorides nanocrystals with favorable fluorescence efficiency. LaF 3 nanocrystals were achieved through this modified MSS method by only using La(NO 3 ) 3 ·6H 2 O and NH 4 HF 2 as starting materials. NH 4 HF 2 is difunctionality as both fluorine source and the flux. The effects of reaction time and temperature to the synthesis of LaF 3 nanocrystals were discussed in detail. The fluorescence of LaF 3 nanocrystals was detected with excitation wavelength of 360 nm, the results showed a broad band emission centered at 475 nm. The photoluminescence properties of pure LaF 3 nanocrystals and Eu 3+ doped samples were also investigated. In our work, white light emission was achieved in single element (Eu 3+ ) doped LaF 3 nanocrystals by adjusting the concentration of Eu 3+ ions. This would be the combination of broad emission of LaF 3 nanocrystals and sharp line emission of Eu 3+ in the LaF 3 :Eu 3+ nanocrystals.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
·
2023
·Vol. 220
·期 13
·2300087
·
IF 2
Zhou Zou,Dengwei Zhang,Arun Murali,Chaoyi Chen,Li Liu,Yuanpei Lan,Junshan Zhang,Fengyuan Liu,Zhiyao Chu,Deyang Ning,Junqi Li
Herein, size-controllable spherical yttrium carbonate powders with D 50 in range from 225 to 743 nm are synthesized from Y(NO 3 ) 3 ·6H 2 O and urea. With the rise of the concentration ratio of urea/Y 3+ , temperature, and extension of aging time, diameter of yttrium carbonate spheres increases. When the urea/Y 3+ is 40: 1 and ages for 4 h at 90 °C, the D 50 of synthesized powder, which has been determined as Y(OH)CO 3 ·1.3H 2 O, has the largest D 50 of 743 nm with (D 90 –D 10 )/2D 50 of 0.22. After decomposition, the D 50 of formed Y 2 O 3 decreases to 632 nm, the (D 90 –D 10 )/2D 50 is 0.24, and the D 50 of Y 2 O 3 is in the range of 126–632 nm. Then, 6 mol. % Eu 3+ is homogeneously doped into Y(OH)CO 3 ·1.3H 2 O and Y 2 O 3 : Eu 3+ spherical powder is obtained after roasting, which exhibits a strong emission peak at 613 nm. The developed synthetic method and the obtained size-controllable spherical Y(OH)CO 3 ·1.3H 2 O, Y 2 O 3 , and Y 2 O 3 : Eu 3+ with a uniform size distribution own various potential applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2019
·Vol. 19
·期 12
·7840-7845
·
IF 1.093
Cheng Zi-Qiang,Yu Ping,Shi Hai-Quan,Liu Zhi-Min,Cheng Guang-Ling,Cheng Hong-Bo,Liang Shan
In this study, In(OH)3 nanocrystals with three morphologies including rods, cubes and spheres were synthesized through a hydrothermal method. The morphology and crystalline were manipulated by controlling the growth speed and the addition of ascorbic acid. The InVO4
nanocrystals were obtained by a process sacrificing In(OH)3 templates. The phase transformation of rods and cubes generated size-controllable products, whereas that of nanospheres formed hollow micro-spheres. InVO4 nanocrystals display a brilliant yellow emission band
with the peak at 517 nm. Intriguingly, luminescent rare-earth Eu ions with red emission could be doped into InVO4 nanocrystals during the phase transformation. Excitation and the emission spectra indicated an excitation energy transfer from the vanadate to the rare-earth ions.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xinzhe Zhou,Li Guan,Huanrong Li
The white LEDs with high performance and excellent luminous quality is of high importance for developing the current lighting industry, and high thermally stable blue phosphors play a critical role in the preparation of white LEDs. Herein, we reported a facile way to obtain highly efficient blue Eu 2+ -doped celsian phosphor with excellent thermal stability by a phase transformation of Ba 2+ -exchanged SOD Zeolite strategy. The structure of phosphors changed from nepheline to celsian with the doping of Ba 2+ , and the maximum emission intensity blue-shifts from 550 nm to 450 nm under the excitation of 370 nm. The PLQY is determined to be 56 %, 96 % and 82 % for the phosphor with Ba 2+ doping concentration being 0, 1.49 and 1.86, respectively, and the luminescence intensity at 423 K is can be 80 %, 102 % and 93 % of its intensity at room temperature. Finally, the package of the LED device based on our yellow and blue phosphors together with the commercial red CaAlSiN 3 :Eu 2+ phosphor is constructed to show warm white light with the CCT of 3705 K and a high CRI of 97.7. This study provides a facile way for obtaining satisfactory phosphors for high-quality lighting.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Yuexin Wang,Yanhua Song,Xiuqing Zhou,Keyan Zheng,Ye Sheng,Pingchuan Ma,Bowen Zhang,Meiqi Chang,Haifeng Zou
Uniform Lu 2 (C 4 H 4 O 6 ) 3 ·6H 2 O cauliflower-like microspheres have been synthesized via a direct precipitation method at room temperature, without any templates and catalysts. The solvent-dependent morphological evolution and the formation mechanism of the Lu 2 (C 4 H 4 O 6 ) 3 ·6H 2 O cauliflower-like microspheres were investigated in detail. Furthermore, Eu 3+ /Tb 3+ -doped Lu 2 O 3 inherited their parents' morphology were obtained through a direct annealing process. The Lu 2 (C 4 H 4 O 6 ) 3 ·6H 2 O:Eu 3+ , Lu 2 O 3 :Eu 3+ exhibit strong red emission corresponding to the 5 D 0 - 7 F j transition of the Eu 3+ ions. The Lu 2 (C 4 H 4 O 6 ) 3 ·6H 2 O:Tb 3+ , Lu 2 O 3 :Tb 3+ exhibit strong green emission corresponding to the 5 D 4 - 7 F j transition of the Tb 3+ ions under UV light excitation. The samples may have potential applications in the fields, such as light-emitting phosphors, advanced flat panel displays, or biological labeling.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Science Letters
·
2012
·Vol. 10
·期 1
·274-278
·
IF 0
Liu Chenglu,Wang Fang,Zhou Zhiqiang,Jia Peiyun
YNbO4:Eu nano-phosphors were successfully prepared in NaNO3 molten salt. X-ray diffraction was used to characterize the structure of the samples. The results indicate that a suitable amount of NaOH in NaNO3 molten salt can effectively improve the crystallinity
of the samples annealed at same temperature; meanwhile, the elevation of annealing temperature increases the crystallinity, and transfers the crystalline phase from scheelite to fergusonite. The micrographs of transmission electron microscopy reveal that the grain size increases with the elevation
of annealing temperature. Upon excitation into the niobate groups at 260 nm, YNbO4:Eu nano-phosphors exhibit weak emission at 405 nm, originated from Nb–O charge transfer transition and the characteristic emission of Eu3+, which indicates there is an energy transfer
from niobate group to Eu3+. Monitored by emission of 615 nm, the excitation spectrum shows that the f-f transition of 7F0–5L6 at 396 nm is more intense than the Nb–O charge transfer band at 260 nm. This intense absorption at
396 nm make YNbO4:Eu nano-phosphors an excellent candidate of white light emitting diode.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Shuang Cao,Zhuoyi Zhang,Yunshuo Wu,Yuxin Sun,Zhe Li,Yanxia Gao,Haiqiang Wang,Xuanhao Wu,Zhongbiao Wu
Nitrous oxide (N 2 O) is a potent greenhouse gas with high global warming potential. It is urgent to develop active and stabile catalysts for N 2 O direct catalytic decomposition (deN 2 O) in industrial exhaust gas. In this study, a series of Eu-doped NiO catalysts were synthesized by co-precipitation method. The catalyst with an Eu to Ni molar ratio of 0.04 showed the highest deN 2 O ability, reaching 100 % conversion at 400 °C without generating NO x by-products. The catalyst also displayed resilience against O 2 and NO impurity gases, maintaining structural stability and achieving complete transformation of N 2 O at 440 °C. Eu was uniformly dispersed in NiO in the form of Eu 2 O 3 , which not only regulated the particle size and specific surface area of NiO, but also changed the surface chemistry of NiO by inducing more Ni 2+ active sites and more mobile O β species. Eu-doping altered the decomposition mechanism of N 2 O from L-H to E-R mechanism, reducing the energy barrier of O 2 desorption, which was the rate-determining step. During the reaction, Eu 0.04 Ni showed an activation behavior after cyclic use and long-term reaction and reduced T 100 to 320 °C after 14-hr experiment. These findings demonstrate the potential of the catalyst for practical application and provide new routes for the direct decomposition of N 2 O in industrial exhaust gas.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）