JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2023
·
IF 3.5
Mingjun Zhao,Yiting Tao,Panting Wang,Ting Wu,Danping Chen,Wei Chen
This study discovered that a transparent BaF 2 -B 2 O 3 glass system without rare-earth ions prepared under CO-reducing atmosphere exhibited orange-red self-luminescence under near-UV light, generating broadband luminescence from 550∼850 nm centered at 650 nm under broadband light excitation at about 397 nm. Based on the results of spectra, electron spin resonance, Raman, and X-ray photoelectron spectroscopy, it is proposed that the luminescence phenomenon is due to the s→p transition of B 2+ generated inside the glass under the reducing atmosphere. This new luminescent glass has the potential to be an orange-red luminescent material excited by a light-emitting diode.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Xinwen Liu,Guolong Tan,Zhiwei Zhou,Weiwei Li,Yu Yang,Zaichun Sun,Bingchu Mei
As one of the quickest inorganic scintillators, BaF 2 crystal is projected to be used in medical treatment, high energy physics, geological research, and other sectors. A series of Pr:BaF 2 polycrystalline transparent ceramics with nominal Pr 3+ concentrations (0.1–5 at%) were synthesized via HP sintering in this research. XRD , FE-SEM, and TEM measurements were used to analyze the phase composition and microstructure of BaF 2 precursor powders with varying Pr-doping levels, and the results demonstrated that as concentration increases, the size of the nanopowders decreases. Furthermore, the morphology shifted from uniform square to uneven sheet. Cross-sectional SEM pictures of all samples revealed a clean grain boundary with no remaining pores or contaminants. The absorption spectra , emission spectra, and fluorescence lifetime of a group of Pr:BaF 2 transparent ceramics with excellent optical transmittance were measured and discussed after hot-pressing the precursor powders synthesized via co-precipitation method at 900 °C under an axial pressure of 50 MPa for 4 h.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 8
·3862-3872
·
IF 3.784
Xinwen Liu,Zhiwei Zhou,Weiwei Li,Yu Yang,Bingchu Mei
Barium fluoride (BaF 2 ) crystals are attracting much attention as efficient inorganic scintillator promising for high-energy physics, industrial inspection, and other fields because of the fast component of the decay time (0.6 ns) and high radiation resistance. However, two major drawbacks limit its practical application: (i) a slow decay time of ~600 ns is derived from self-trapping excitons; (ii) the absolute light yield from the fast luminescence component is not competitive. The introducing of rare earth ions and preparation of BaF 2 polycrystalline ceramics is considered to be effective measures to solve these bottlenecks. Pr 3+ is extremely suitable as the activated ion of scintillation materials, which possess emission peaks located in visible band and the faster 5 d –4 f transition. In this work, highly sinterable Pr 3+ :BaF 2 precursor powder was synthesized via the coprecipitation method by adjusting the reactant concentration and temperature. The morphology and microstructure of as-synthesized powders were characterized using scanning electron microscopy (SEM) and transmittance electron microscopy analysis. The 5 at.% Pr 3+ :BaF 2 transparent ceramic with a transmittance of 50.7% at the wavelength of 500 nm was fabricated by hot pressing the as-prepared powders at 900°C for 4 h under the axial pressure of 50 MPa. The SEM images of ceramic cross-section show that the residual pore is the main light scattering source. The absorption and emission spectrum of ceramic samples were discussed.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
Frontiers in Chemistry
·
2021
·
IF 5.221
Yuan Jian,Wang Weichao,Ye Yichen,Deng Tingting,Ou Deqian,Cheng Junyang,Yuan Shengjin,Xiao Peng
The effects of substitution of BaF2 for BaO on physical properties and 1. 8 μm emission have been systematically investigated to improve spectroscopic properties in Tm3+ doped gallium tellurite glasses for efficient 2.0 μm fiber laser. It is found that refractive index and density gradually decrease with increasing BaF2 content from 0 to 9 mol.%, due to the generation of more non-bridging oxygens. Furthermore, OH− absorption coefficient (αOH) reduces monotonically from 3.4 to 2.2 cm−1 and thus emission intensity near 1.8 μm in gallium tellurite glass with 9 mol.% BaF2 is 1.6 times as large as that without BaF2 while the lifetime becomes 1.7 times as long as the one without BaF2. Relative energy transfer mechanism is proposed. The maximum emission cross section and gain coefficient at around 1.8 μm of gallium tellurite glass containing 9 mol.% BaF2 are 8.8 × 10−21 cm2 and 3.3 cm−1, respectively. These results indicate that Tm3+ doped gallium tellurite glasses containing BaF2 appear to be an excellent host material for efficient 2.0 μm fiber laser development.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the American Chemical Society
·
2022
·
IF 16.383
Qian Zhang,Yong-Hui Song,Jing-Ming Hao,Yi-Feng Lan,Li-Zhe Feng,Xue-Chen Ru,Jing-Jing Wang,Kuang-Hui Song,Jun-Nan Yang,Tian Chen,Hong-Bin Yao
All-inorganic CsPbI3 perovskite is attractive for deep-red light-emitting diodes (LEDs) because of its excellent carrier mobility, high color purity, and solution processability. However, the high phase transition energy barrier of optically active CsPbI3 black phase hinders the fabrication of efficient and bright LEDs. Here, we report a novel α-BaF2 nanoparticle substrate-promoted solution-processable heteroepitaxial growth to overcome this hindrance and obtain high-quality optically active γ-CsPbI3 thin films, achieving efficient and bright deep-red LEDs. We unravel that the highly exposed planes on the α-BaF2 nanoparticle-based heteroepitaxial growth substrate have a 99.5% lattice matching degree with the (110) planes of γ-CsPbI3. This ultrahigh lattice matching degree initiates solution-processed interfacial strain-free epitaxial growth of low-defect and highly oriented γ-CsPbI3 thin films on the substrate. The obtained γ-CsPbI3 thin films are uniform, smooth, and highly luminescent, based on which we fabricate efficient and bright deep-red LEDs with a high peak external quantum efficiency of 14.1% and a record luminance of 1325 cd m–2.
研究领域:
材料科学
·
光电技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Royal Society Open Science
·
2019
·Vol. 6
·期 10
·
IF 2.515
Yongsheng Ling,Guang Wang,Ting Chen,Xionghui Fei,Song Hu,Qing Shan,Daqian Hei,Huajun Feng,Wenbao Jia
BaF2–TiO2 nanocomposite material (hereinafter called the composite) was prepared by a sol–gel method. The composite surface area, morphology and structure were characterized by Brunauer–Emmett–Teller method, X-ray diffraction analysis and a scanning electron microscopy. The results showed that BaF2 and TiO2 form a PN-like structure on the surface of the composite. Composites were used to catalyse the degradation of methyl orange by irradiation with ultraviolet light, γ-rays and an electron beam (EB). It was demonstrated that the composite is found to be more efficient than the prepared TiO2 and commercial P25 in the degradation of methyl orange under γ-irradiation. Increasing the composite catalyst concentration within a certain range can effectively improve the decolorization rate of the methyl orange solution. However, when the composite material is used to catalyse the degradation of organic matter in the presence of ultraviolet light or 10 MeV EB irradiation, the catalytic effect is poor or substantially ineffective. In addition, a hybrid mechanism is proposed; BaF2 absorbs γ-rays to generate radioluminescence and further excites TiO2 to generate photo-charges. Due to the heterojunction effect, the resulting photo-charge will produce more active particles. This seems to be a possible mechanism to explain γ-irradiation's catalytic behaviour.
研究领域:
环境科学
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材料科学
·
辐射化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Mo Wei,Juan Liu,Bing Liu,Kai Xin Song,Cheng Chao Hu,Yu Hui Huang
Alkaline earth metal fluorides, BaF 2 and SrF 2 , are promising low-permittivity ceramics with excellent microwave dielectric properties. However, achieving ideal densifications in BaF 2 and SrF 2 ceramics remains challenging due to their low surface-free energy. In this study, the sintering characteristics of BaF 2 and SrF 2 ceramics are optimized via forming (1– x )BaF 2 - x SrF 2 ( x = 0.2, 0.4, 0.5, 0.6, and 0.8) solid solution ceramics. X-ray diffraction (XRD) patterns and Raman spectra provide compelling evidence for successfully forming (1– x )BaF 2 - x SrF 2 solid solutions across the entire composition range. The solid-solution effect significantly enhances densification at a much lower sintering temperature of around 825 °C. Notably, 0.6BaF 2 -0.4SrF 2 ceramics exhibit the optimal microwave dielectric properties with a permittivity ( ε r ) of 7.26, quality factors ( Qf ) of 61,006 GHz at 10 GHz and 106,000 GHz at 25 GHz, and a temperature coefficient of resonant frequency ( τ f ) of −97.46 ppm/ ° C. Additionally, the advancement of low-temperature co-fired ceramic (LTCC) technology for high-density electronic packaging presents a significant challenge in achieving compatibility between the coefficient of thermal expansion (CTE) of the packaged components. The 0.6BaF 2 -0.4SrF 2 ceramics exhibit a significantly higher CTE of 21.67 ppm/ ° C compared to most low- ε r ceramics (usually below 10 ppm/ ° C), resulting in better CTE matching with organic laminates and metal electrodes. Therefore, BaF 2 -SrF 2 solid solution ceramics, addressing the need for low- ε r , high- Qf , and high CTE, offer a potential solution for high-reliability LTCC electronics.
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
JOURNAL OF RARE EARTHS
·
2017
·
IF 2.429
Jiansheng Huang,Ronghui Liu,Yuanhong Liu,Yunshen Hu,Guantong Chen,Chunpei Yan,Junhang Tian,Bin Hu
Eu 2+ activated BaSi 2 O 2 N 2 oxynitride bluish-green phosphor was synthesized adopting conventional high-temperature solid-state reaction method, in which BaF 2 , Na 2 CO 3 and NH 4 Cl were used as the fluxes. The phase formation, size distribution and microscopic morphology were characterized to investigate the influence of adding fluxes on photoluminescence properties. The results indicate that with the addition of BaF 2 flux, the particle morphology becomes regular and size distribution narrows and the phase purity of BaSi 2 O 2 N 2 :Eu 2+ phosphor can be improved effectively. The photoluminescence intensity of BaSi 2 O 2 N 2 :Eu 2+ phosphor with BaF 2 as flux gets enhanced obviously, which is much higher than that of Na 2 CO 3 , NH 4 Cl and without flux. The optimum content of BaF 2 flux is 4 wt%, and the maximum photoluminescence intensity of the BaSi 2 O 2 N 2 :Eu 2+ phosphor prepared with BaF 2 flux rises to 141%, meanwhile, the phosphors with BaF 2 flux exhibits low thermal quenching. The results indicate that the BaSi 2 O 2 N 2 :Eu 2+ is sort of promising bluish-green phosphor for application in full-spectra LED.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Crystals
·
2023
·Vol. 13
·期 9
·1334
·
IF 2.7
Xiang Li,Mingxue Deng,Yun Shi,Xuejun Qi,Shaohan Wang,Yugui Lu,Yong Du,Junfeng Chen
Organic–inorganic composite scintillators, demonstrating advantages of easy large-area preparation and a high detection efficiency, have shown enormous potential application prospects in radiation detection and imaging. In this study, bulk polystyrene (PS) composite scintillators were successfully prepared by embedding inorganic BaF2particles with a loading amount of up to 80 wt% during the polymerization process of the plastic scintillator. The inorganic BaF2particles were uniformly dispersed in the organic matrix. With the increase of the loading amounts of BaF2particles, the X-ray-excited luminescence intensity of the PS-BaF2composite scintillators was about eight times higher than that of the commercial pure plastic scintillator. The scintillation counts under the gamma ray (59.5 KeV) irradiation also showed that the detection efficiency was obviously enhanced by BaF2particle loading. More importantly, their scintillation pulse retains the decay kinetics of the organic matrix without loading the slow-decay component of BaF2. This work provides a promising solution for the application of the PS-BaF2composite scintillator in high-efficiency radiation detection and large-area imaging.
✓ 已验证
DOI
高影响因子
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
·
2020
·
IF 1.265
Junjie Li,Jinghong Song,Weiwei Li,Bingchu Mei,Zuodong Liu,Yongqiang Zhang
In this study, high concentration (5 mol%) of cerium doped barium fluoride transparent ceramic was fabricated by hot pressing method t a temperature of 1200 °C under 30 MPa. XRD (X-ray Diffraction), SEM (Scanning Electron Microscope), PLE (Photoluminescence Emission) measurements was used to investigate the phase composition, microstructure as well as photoluminescence properties of Ce 3 + : BaF 2 . XEL (X-ray Excited Luminescence) and pulse height spectrum were used to investigate the scintillation properties of this ceramic. The phase composition and microstructure analyses showed that the Ce 3 + : BaF 2 precursor nanoparticles prepared by the co-precipitation method were uniform and have a average size of 25 nm. The highest transmittance of the ceramic was 77% at the wavelength of 2300 nm. The PL (photoluminescence) spectrum showed that the 5d–4f transition of Ce 3 + : BaF 2 transparent ceramic is located at 340 nm. X-ray excited luminescence exhibited only one violet peak at 392 nm. Scintillation decay time measurements showed only a slow component of 437 ns under 662 keV gamma excitation.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 25
·7905-7909
·
IF 7.393
Heng Yang,Huihui Li,Rui Yuan,Junfeng Chen,Jingtai Zhao,Sheng Wang,Yufeng Liu,Qianli Li,Zhijun Zhang
Traditional inorganic scintillation crystals have a high stopping power to high-energy particles or rays; however, their wide applications are limited due to the fixed emission band. CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (CsPbX3 NCs) have been proved to achieve full-color emission and effective X-ray detection, but failed to detect γ-rays effectively due to their weak absorption ability. Therefore, based on the advantages of the tunable spectra for CsPbX3 NCs and the high stopping ability of a BaF2 single crystal, a novel CsPbX3 NCs@BaF2 scintillation screen is developed ingeniously for realizing fast and full-color emission under high-energy ray excitation. The CsPbX3 NCs@BaF2 scintillation screen exhibits a tunable emission ranging from 435 to 648 nm under hard X-ray excitation. It is of note that the light yield of the CsPbBr3 NCs@BaF2 scintillation screen can reach up to 6300 photons per MeV and it shows a fast decay time component (∼11 ns) under γ-ray excitation. The purpose of this contribution is to provide a new solution for guiding the perovskite materials as potential scintillators for fast and full-color emission expanding the application of high-energy radiation detection.
研究领域:
材料科学
·
物理学
·
辐射检测
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2015
·
IF 2.259
Xiaowen Zhang,Zhi Chen,Jianrong Qiu
Near infrared to visible up-conversion luminescence in Er 3+ single doped BaCl 2 , BaF 2 and NaYF 4 phosphors were compared. Intense blue emission at 410 nm due to 2 H 9/2 → 4 I 15/2 transition and greenish-blue emission at 496 nm due to 4 F 7/2 → 4 I 15/2 transition were only observed in BaCl 2 :Er 3+ when excited by 808 nm and 976 nm laser diodes , respectively. The phenomena can be ascribed to the direct two-step excitation processes which occur in the chlorides where multiphonon relaxation is rapidly suppressed. In addition, the intensity of upconversion emission in BaCl 2 :Er 3+ is greatly enhanced upon broadband near-infrared excitation.
研究领域:
材料科学
·
光学材料
·
无机化学
·
发光物理
·
纳米生物技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）