JOURNAL OF ALLOYS AND COMPOUNDS
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2015
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IF 2.999
Renping Cao,Wenjie Luo,Qingqiang Xiong,Aihui Liang,Shenhua Jiang,Yongchun Xu
LiRGe 2 O 6 :xMn 4+ (R = Al or Ga) (0 ≤ x ≤ 1.0 mol%) phosphors are synthesized by solid-state reaction method in air, and their crystal structures, luminescence properties, and fluorescence lifetimes are investigated. Their photoluminescence (PL) bands peaking at ∼ 670 nm owing to the 2 E → 4 A 2 transition of Mn 4+ ion cover the region from 620 to 750 nm (λex = 289 nm), and photoluminescence excitation (PLE) bands (λem ≈ 670 nm) are observed in the range of 200–550 nm. With excitation 289 nm, PL intensity of LiAlGe 2 O 6 :0.6%Mn 4+ phosphor is far stronger than that of LiGaGe 2 O 6 :0.6%Mn 4+ phosphor owing to the influence of crystal field. The optimal Mn 4+ ions concentration is ∼0.6 mol%. The fluorescence lifetime and quantum efficiency of LiAlGe 2 O 6 :0.6%Mn 4+ and LiGaGe 2 O 6 :0.6%Mn 4+ phosphors are ∼1.55 ms, 68.5 μs, 32%, and 15%, respectively. Luminous mechanism, the temperature quenching mechanism, and the influence of crystal field to luminous properties are analyzed and discussed, respectively. The experiment results are helpful to develop other novel Mn 4+ -doped phosphors.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2020
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IF 2.463
Xingbang Dong,Huanjun Zhang,Yang Yang,Shiquan Feng,Zheng Wang,Chaosheng Yuan,Kun Yang,Xuerui Cheng
InNbO 4 and InNbO 4 :Eu 3+ phosphors were synthesized by solid-state reaction method. The structural stability and crystal field under high pressure are investigated up to 34.5 GPa using in-situ Raman and luminescence spectra . The evolution of Raman and luminescence spectra with pressure of InNbO 4 revealed one reversible phase transition at around 12 GPa. A progressive red shift and luminescence quenching were observed for InNbO 4 :Eu 3+ phosphors during compression. The pressure-induced variation of local environment and crystal field around Eu 3+ ions was analyzed using Judd–Ofelt (J-O) intensity parameter Ω 2. Both the parameter Ω 2 and luminescence property were indicative of a pressure-induced lower asymmetry around Eu 3+ sites in InNbO 4 . These results suggest that the pressure has a great influence on fluorescence intensity and energy levels of Eu 3+ ions.
研究领域:
材料科学
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物理学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2019
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IF 4.309
Xiaolei Lu,Shuxian Wang,Shuxin Liu,Peng Du,Zhengmao Ye,Xuefei Geng,Xin Cheng
Ca2SiO4 is a phase-change material, and γ- and β-Ca2SiO4 usually coexist in the sintered product. The overlap of the diffraction data between the two polymorphs makes the relevant phase identification difficult. In this work, the Eu3+ rear-earth fluorescence probe is introduced in the preparation of Ca2SiO4, and the obtained result indicates that the introduction of Eu3+ ions facilitates the increase in the content of β-Ca2SiO4 in the final product. In addition, the differences of the local coordination environments between the two Ca2SiO4 phases obviously influence the crystal-field splittings of Eu3+ ions, especially in the 5D0 → 7F0 nondegenerate and 5D0 → 7F1 magnetic dipole transition regions. On the basis of the excitation from the Eu3+–O2– charge-transfer band, the low-temperature spectral changes are systematically discussed. The transition area ratios of 5D0 → 7F0/5D0 → 7F2 and 5D0 → 7F1/5D0 → 7F2 present a positive and negative correlation with the increase of the excitation wavelength, respectively. The four nonequivalent 5D0 → 7F0 emission peaks with low to high wavelengths are identified as Eu3+ ion-occupied Ca(β-2) (571.8 nm), Ca(β-1) (573.8 nm), Ca(γ-2) (577.6 nm), and Ca(γ-1) (578.9 nm) sites. Besides, the relationship between the phase content of γ-Ca2SiO4 and the spectral change for the 5D0 → 7F0 emissions of the Eu3+ ions is also built. It is fitted by an exponential correlation function and is quite suitable for the prediction of the phase content of γ-Ca2SiO4 based on the measured spectra. The findings in this study manifest the promising application of the Eu3+ fluorescent probe in phase identification and enrich the analysis method in inorganic phase-change materials.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
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IF 3.6
Lin Xiang,Xianju Zhou,Li Li,Faling Ling,Yanhong Li,Jingfang Li,Hongmei Yang
Eu 3+ ions are extensively employed as spectroscopic probes because of the particular emissions due to the unique 4f 6 electronic configuration. Herein, we have developed a series of interesting fluorescent powders of Eu 3+ activated Sr 2 MNbO 6 (M = Ga, In, Gd). When Sr 2 GaNbO 6 :Eu 3+ is excited by the photons in the range of charge transfer band (CTB), the dark red 5 D 0 → 7 F 4 transition predominates the emission, exhibiting an anomalous intensity even higher than that of 5 D 0 → 7 F 1 or 5 D 0 → 7 F 2 . Whilst, if the sample is pumped by f-f characteristic transitions, the hypersensitive 5 D 0 → 7 F 2 transition emerges as the strongest. However, Eu 3+ doped Sr 2 InNbO 6 and Sr 2 GdNbO 6 never demonstrate such results, 5 D 0 → 7 F 1 acts as the most intense one regardless of the excitation wavelength. It is found that Eu 3+ substitutes Sr 2+ site, and cuboctaherdron [SrO 12 ] with O h symmetry is likely to deform to triangular orthobicupola D 3h symmetry, leading to two non-equivalent crystal sites in Sr 2 GaNbO 6 host. But Eu 3+ replaces In 3+ and Gd 3+ position with O h symmetry and has only one site in Sr 2 InNbO 6 and Sr 2 GdNbO 6 . Based on the comparative study on the intensity of 5 D 0 → 7 F 0 transition, as well as the influence factors of temperature, the doping concentration on the relative intensity among 5 D 0 → 7 F J transitions, and the band gaps of these three hosts, the origin of the abnormal intense 5 D 0 → 7 F 4 is ascribed to the mixing of CTB and low-lying 4f 6 configuration as well as two non-equivalent Eu 3+ sites.
研究领域:
材料科学
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光物理学
✓ 已验证
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
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2019
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IF 4.153
Ziqing Li,Pengfei Zhu,Jimin Ding,Nianjing Ji,Yang Chen,Zhenyan Wang,Xiulan Duan,Huaidong Jiang
Yb-doped inorganic crystals have attracted great attention in both basic and applied research, and the quest for suitable crystal hosts and understanding the corresponding crystal field environments are still worth studying in laser application. In this context, inclusion-free RbTiOPO4:Ta:Yb (RTP:Ta:Yb) single crystals with dimensions up to 3 × 30 × 15 mm3 were grown by top-seeded solution growth method under optimized growth conditions. The good crystalline quality of the as-grown RTP:Ta:Yb crystals were confirmed by X-ray diffraction rocking curve. The chemical compositions of the crystals were determined through electron probe microanalysis (EPMA). The results showed that the Ta distribution coefficient is 0.90–1.28, and the Yb distribution coefficient is 0.13–0.37. Double doping of Ta5+ ions can effectively increase the concentration of Yb3+ ions in the RTP crystal, and the concentration of Yb3+ ion in RTP crystal can reach 1.26 × 1020 atom/cm3. The influence of Ta and Yb dopants on the electronic structures of RTP crystals was studied using high-resolution X-ray photoelectron spectroscopy (XPS), and the chemical strengths of Ti–O and P–O bonds are related to the binding energy difference. RTP:Ta:Yb crystals exhibit excellent transparent performance in the wavelength range of 0.35–4.5 μm, and the transmittance is about 83%. Photoluminescence spectra show five emission peaks of Yb3+ in crystals, and the main emission peak is located at 972 nm. Two different coordination sites for Yb3+ were observed, and their energy levels were determined in the crystal field of the RTP:Ta structure. Furthermore, the crystal field strengths of Yb3+ in different host crystals associated with their distorted coordination environments were evaluated and discussed in detail. The results demonstrate that the RTP:Ta:Yb single crystal endowed with high crystal field strength and good luminescence property is suitable for laser application.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
You Zhang,Kun Zhao,Haoyu Zhu,Qiong Xi,Nian Fu,Dawei Wang,Jinxing Zhao,Li Guan,Yunfei Zhuang,Xu Li
White light-emitting diodes (WLEDs) have emerged as a leading technology for healthy lighting and advanced displays. Nevertheless, the poor thermal stability of blue-emitting components remains a significant bottleneck, hindering their broader adoption in demanding environments. Here, we have prepared a series of Ca 3 Al 2 O 6 :Ce 3+ phosphors by high temperature solid-state method. Substituting the [Al 3+ –O 2- ] ionic pair with [Si 4+ –N 3- ] in the Ca 3 Al 2 O 6 host lattice via a charge-compensated strategy achieves a 1.75 times enhancement in thermal stability compared to the pristine material, while simultaneously inducing a blue-shifted emission spectrum (Δλ = 30 nm). The enhanced thermal stability originates from increased lattice rigidity, while the blue spectral shift arises from modulated crystal field splitting decrease. These mechanistic insights provide a foundational strategy for designing ultra-stable blue phosphors compatible with high-power WLED applications.
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
Chemical Physics Impact
·
2025
·
IF 4.3
Zixuan Jiang,Bing Liu,Zehua Zhang,Lili Wang,Zhixu Jia,Dan Zhao
The co-doping effect of Zr 4+ ions on upconversion (UC) luminescent properties in visible region of Y 2 O 3 : Er 3+ and Y 2 O 3 : Er 3+ , Yb 3+ sub-microcrystals prepared by urea precipitation method has been investigated under 980 nm excitation. Compared with the original Y 2 O 3 : Er 3+ and Y 2 O 3 : Er 3+ , Yb 3+ sub-microcrystals, the UC luminescence of sub-microcrystals with similar size was enhanced after Zr 4+ ions co-doping. The UC luminescent properties have been discussed in detail via luminescence spectra, decay curve analysis and a suitable energy level diagram. The enhancement mechanism of UC luminescence in the two series of Zr 4+ ions doped sub-microcrystals was attributed to the complex crystal field around Er 3+ ions caused by Zr 4+ ions co-doping. After Zr 4+ ions substituted Y 3+ ions and entered the crystal lattice, the charge mismatch and lattice distortion made the crystal field more complex. This research contributes to the understanding of UC luminescent properties of lanthanide (Ln 3+ ) ions doped UC materials and their technological applications in fields such as bioimaging, drug delivery, and optical temperature sensors.
研究领域:
材料科学
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光学
·
生物成像
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药物递送
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光学温度传感器
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Renping Cao,Wudi Wang,Jinlong Zhang,Shenhua Jiang,Zhiquan Chen,Wensheng Li,Xiaoguang Yu
Novel Li 2 SnO 3 :Mn 4+ red-emitting phosphor is synthesized by high-temperature solid-state reaction method in air. Emission band of Li 2 SnO 3 :Mn 4+ phosphor within the range 620–760 nm is attributed to the 2 E → 4 A 2 electron transition of Mn 4+ ion. Excitation bands peaking at 330, 395, and 480 nm are attributed to O 2- → Mn 4+ charge transfer and 4 A 2 → ( 4 T 1 , 2 T 1 , and 4 T 2 ) transitions of Mn 4+ ion, respectively. The optimal Mn 4+ concentration is ∼0.4 mol% and the corresponding quantum efficiency and lifetime are ∼42.3% and 16.3 μs. The influences of temperature and Mn 4+ concentration to emission intensity are discussed and analysized. Lifetime data and time resolved spectra confirm that there is only a single type of Mn 4+ ion luminescent center in Li 2 SnO 3 :Mn 4+ phosphor. The influences of the crystal field and the “Mn 4+ -ligand” bonding to luminescence properties of Mn 4+ ion are summaried and analysized. The luminous mechanism is explained via Tanabe-Sugano energy level diagram and the configuration coordinate diagram of Mn 4+ in the octahedron. The results indicate that Li 2 SnO 3 :Mn 4+ phosphor has a hope to be used as red phosphor candidate for solid-state lighting.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2025
·
IF 7.2
Dilare Halmurat,Xinyu Zhang,Litipu Aihaiti,Rong-Jun Xie
Eu 2+ -doped phosphors show broadband absorption, tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions, allowing them to be used in solid-state lighting. To expand their applications in other fields such as detection and sensing technologies, the Eu 2+ emission needs to be tuned into the near-infrared region, but it is a big challenge to obtain Eu 2+ near-infrared region emitters due to the absence of host compounds with extremely large crystal-field splitting. In this work, we chose M 4 Li(BN 2 ) 3 (M = Ca, Sr, Ba) as a host and realize the near-infrared region emission of Eu 2+ in it. Among these phosphors, Ba 4 Li(BN 2 ) 3 :Eu 2+ exhibits the longest emission of 880 nm and the largest full-width at half maximum of 276 nm under 450 nm excitation, while Ca 4 Li(BN 2 ) 3 :Eu 2+ and Sr 4 Li(BN 2 ) 3 :Eu 2+ emit at 740 and 680 nm, respectively. We observe an interesting phenomenon that the energy shift of emission is linearly related to the radius difference between the alkaline earth cation and the activator Eu 2+ in this system.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2024
·
IF 6.1
Zhijiao Zhao,Mengmeng Dai,Kejie Li,Guiying Liang,Yanling Wei,Zuoling Fu
The exploration of acquiring excellent thermal performance of luminescence thermometers has become a key focus, owing to their non-contact measurement, high spatial resolution and rapid response. However, many luminescence thermometers still suffer from unsatisfactory relative sensitivity and a single temperature sensing mode. Herein, we report a Lu2CaMg2Ge3O12 garnet structure oxide with a stronger crystal field for ultra-sensitive and multimodal luminescence intensity ratio (LIR) optical thermometry based on the thermally coupled levels (TCLs) of Nd3+ (4F7/2 and 4F3/2) and Er3+ (2H11/2 and 4S3/2), where the relative sensitivity (Sr) can be up to 2.62% K−1 and 1.15% K−1, respectively. Furthermore, the energy level splitting factor Ke, which is used to quantify the energy level splitting extent of the doped ions, is estimated with the help of the dielectric chemical bond theory of complex crystals. As a result of the strong crystal field, the near-infrared (NIR) light-responsive temperature sensing performance of Er3+ (4I13/2) is enabled by the Stark sublevels with the relative sensitivity value of 0.46% K−1. This work not only provides a fresh perspective for developing optical thermometers with outstanding temperature performance, but also provides inspiration for pursuing a multimodal luminescence thermometer.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Weishun Jian,Xinyu Hu,Jinqiang Gao,Jingyao Zeng,Yu Mei,Haoji Wang,Ningyun Hong,Jiangnan Huang,Kai Wang,Wentao Deng,Guoqiang Zou,Hongshuai Hou,Hongyi Chen,Xiaobo Ji
Na4Fe3(PO4)2(P2O7) (NFPP) is a promising cathode material for sodium-ion batteries with cost-effectiveness and structural stability. However, its electrochemical behaviors are seriously hindered by its [P2O7] distortion at high voltage. To address this challenge, we introduce a distortion criterion and optimize the local crystal field environment by incorporating Cr3+ into Fe3 sites adjacent to [P2O7]. This substitution elongates Fe1–O bonds, enhances Fe1 activity, and suppresses [P2O7] distortion, facilitating fast Na+ diffusion and structural reversibility, as validated by X-ray absorption fine structure (XAFS) and density functional theory (DFT) calculations. Based on c-axis changes during high-voltage operation, a quantitative method for assessing [P2O7] distortion is proposed and confirmed by operando X-ray diffraction (XRD). The optimized NFPP-0.15Cr exhibits exceptional rate performance (91.74 mAh g–1 at 50C), long-term cycling stability (88.81% capacity retention after 10,000 cycles at 50C), and wide temperature tolerance (−40 to 60 °C). This study provides a strategic approach for designing high-performance iron-based mixed phosphate cathodes, advancing their practical application in sodium-ion batteries.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Feng Hong,Long Li,Maoyu Xu,Haiqing Su,Yunkai Dong,Jingjing Zhang,Dechuan Yu,Hai Lin
Mn 4+ -doped fluoride phosphors have important application value in the background light and WLED lighting fields. Therefore, the synthesis of efficient and stable Mn 4+ -doped red phosphor is of great application value. In this study, a series of red-emitting K 2 NaAl 1- y Ga y F 6 : x Mn 4+ ( y = 0, 0.2, 0.4, 0.6, 0.8 and 1) ( x = 0.01, 0.03, 0.05, 0.07 and 0.09) solid solution phosphors are successfully synthesized by simple coprecipitation method. The synthesis strategy of simple crystal structure optimization is proposed to realize simultaneously the crystal field optimization, luminescence enhancement and thermal stability of red phosphor. The calculation and theoretical analysis of crystal field strength are used to prove that solid solution matrix K 2 NaAl 0.4 Ga 0.6 F 6 is the most ideal matrix material. X-ray powder diffraction, energy-dispersive X-ray spectrometer and scanning electron microscope are employed to determine the crystal structure, composition and morphology of all samples. Optical properties are characterized using excitation spectra, emission spectra and fluorescence lifetime curves. Moreover, the CIE coordinates of red-light show that the phosphor has low correlated color temperature and excellent color purity. Intriguingly, the as-prepared K 2 NaAl 0.4 Ga 0.6 F 6 :Mn 4+ phosphor possesses admirable thermal quenching behavior and color stability at high temperature. At a temperature of 423 K, the photoluminescence intensity can be maintained at 52 % of the original intensity (298 K). The activation energy, the chromaticity shift and chromaticity coordinate variation are also systematically calculated. More importantly, A high-performance warm WLED with low correlated color temperature (CCT = 3982 K) and high color rendering index (R a = 93.7) is achieved by using K 2 NaAl 0.4 Ga 0.6 F 6 :Mn 4+ as a red-emitting material. These results demonstrate that K 2 NaAl 0.4 Ga 0.6 F 6 :Mn 4+ red phosphor provides a novel choice for the warm WLED required for indoor 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
危险品化学品经营许可证（带存储）