Significant enhancement of cathode-ray scintillation for a conductive Bi-SMOF via in situ partial rare earth ion replacement

2019 ◽  
Vol 7 (36) ◽  
pp. 11099-11103 ◽  
Author(s):  
Jian Lu ◽  
Xiu-Hui Zhao ◽  
Bing Bai ◽  
Fa-Kun Zheng ◽  
Guo-Cong Guo

Through in situ partial replacement of Bi3+ ions with rare earth ions like Eu3+ in a conductive Bi(iii)–MOF matrix, the cathode-ray luminescence performance gets significantly enhanced.

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3717
Author(s):  
Jae-Young Jung ◽  
Soung-Soo Yi ◽  
Dong-Hyun Hwang ◽  
Chang-Sik Son

The precursor prepared by co-precipitation method was sintered at various temperatures to synthesize crystalline manganese tungstate (MnWO4). Sintered MnWO4 showed the best crystallinity at a sintering temperature of 800 °C. Rare earth ion (Dysprosium; Dy3+) was added when preparing the precursor to enhance the magnetic and luminescent properties of crystalline MnWO4 based on these sintering temperature conditions. As the amount of rare earth ions was changed, the magnetic and luminescent characteristics were enhanced; however, after 0.1 mol.%, the luminescent characteristics decreased due to the concentration quenching phenomenon. In addition, a composite was prepared by mixing MnWO4 powder, with enhanced magnetism and luminescence properties due to the addition of dysprosium, with epoxy. To one of the two prepared composites a magnetic field was applied to induce alignment of the MnWO4 particles. Aligned particles showed stronger luminescence than the composite sample prepared with unsorted particles. As a result of this, it was suggested that it can be used as phosphor and a photosensitizer by utilizing the magnetic and luminescent properties of the synthesized MnWO4 powder with the addition of rare earth ions.


The theory that has been developed for rare-earth ions in crystals is here applied to the double nitrates. The paramagnetic resonance data and certain spectroscopic properties of the different rare-earth double nitrates, depending as they do on the crystalline electric field at a rare-earth ion, are related to the six parameters through which the field is defined. It is found that most of the experimental results can be fitted to values of the parameters that vary in a systematic fashion along the rare-earth series.


2016 ◽  
Vol 16 (4) ◽  
pp. 4029-4034 ◽  
Author(s):  
Chunxia Liu ◽  
Lixia Yang ◽  
Dan Yue ◽  
Mengnan Wang ◽  
Lin Jin ◽  
...  

Rare earth ions (Tb3+, Eu3+) doped CaWO4 microstructures were synthesized by a facile hydrothermal route without using any templates and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectrum. The results indicate that the asprepared samples are well crystallized with scheelite structure of CaWO4, and the average diameter of the microstructures is 2∼4 μm. The morphology of CaWO4:Eu3+ microstructures can be controllably changed from microspheres to microflowers through altering the doping concentration of Eu3+ from 3% to 35%, and the microflowers are constructed by a number of CaWO4:Eu3+ nanoflakes. Under the excitation of UV light, the emission spectrum of CaWO4:Eu3+ is composed of the characteristics emission of Eu3+ 5D0-7FJ (J = 1, 2, 3, 4) transitions, and that of CaWO4:Tb3+ is composed of Tb3+ 5D4-7FJ (J = 6, 5, 4, 3) transitions. Both of the optimal doping concentrations of Tb3+ and Eu3+ in CaWO4 microstructures are about 5%.


RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86219-86236 ◽  
Author(s):  
Xiangfu Wang ◽  
Qing Liu ◽  
Yanyan Bu ◽  
Chun-Sheng Liu ◽  
Tao Liu ◽  
...  

Optical temperature sensing is a promising method to achieve the contactless temperature measurement and large-scale imaging. The current status of optical thermometry of rare-earth ions doped phosphors is reviewed in detail.


1991 ◽  
Vol 244 ◽  
Author(s):  
L. R. Copeland ◽  
W. A. Reed ◽  
M. R. Shahriari ◽  
T. Iqbal ◽  
P. Hajcak ◽  
...  

ABSTRACTRare earth ions can easily be incorporated into fluoride glasses in moderate to large concentrations and, due to their low phonon energy, these glasses appear to have many advantages over oxide glasses as hosts for rare earth ions used in optical amplifiers and lasers. We have therefore investigated the optical properties of Pr3+, Pr3+/Yb3+ and Pr3+/Yb3+/Lu3+ doped bulk AIF3-based glass samples as a function of rare earth ion concentration. We find that the addition of 2 wt% of Yb increases the fluorescence of Pr3+ at 1.32 μm by a factor of 35 when excited with 488 nm radiation. The fluorescence intensity and excited state lifetimes are found to be comparable to those measured for Pr in a ZBLAN host. Since it has also been demonstrated that optical fibers drawn from AIF3-based glasses exhibit relatively low loss (< 0.05 dB/m) and posses superior chemical durability compared to other fluotide glasses, it is possible that AIF3 glasses may become the fluoride glass of choice for practical fiber laser and amplifier applications.


2021 ◽  
Vol 129 (4) ◽  
pp. 527
Author(s):  
Afrash Ejigu A ◽  
K.P. Ramesh ◽  
Gajanan Honnavar

In this communication, we report physical and thermal properties along with Raman spectroscopic investigations on Zinc Niobo Tellurite glass systems doped with Eu2O3 and Dy2O3 at the expense of TeO2. The glasses have been synthesized by the melt quenching technique. Physical parameters like density, molar volume, packing density were estimated. The density of the un-doped glasses increases with increasing mol&#37; of the modifier (ZnO) whereas the glass transition temperature (Tg) decreases. We have observed an increase in the density of the base glass systems which are doped with rare earth (RE) dopants. The packing density of the un-doped glasses remains almost constant with increasing modifier content suggesting that there is not much change in the local environment. Raman spectra were recorded at room temperature and assigned to TeO4 and TeO3 structural units in these glasses. The peak shift, full width at half maximum (FWHM) of the de-convoluted Raman peaks were analyzed to get information about the local environment. It is observed that these compositions of tellurite glasses are good host materials for rare earth ions as they offer voids in the network. Further, it was observed that the rare earth ion doping has not affected the local environment of the glasses; Dy3+ ions have a slightly higher tendency to polarize Te-O bonds than the Eu3+ ions. Keywords: Niobium-based tellurite glasses, XRD, DSC, FTIR.


2021 ◽  
Vol 13 (2) ◽  
pp. 331-341
Author(s):  
Jinqi Wang ◽  
Guopeng Li ◽  
Wei Wang ◽  
Fuxia Li ◽  
Chuankai Yang ◽  
...  

Photocatalytic degradation of pollutants has attracted much attention because it can effectively solve the problem of environmental pollution. SiO2@Eu(TTA)3phen@TiO2 core-shell structures were successfully synthesized for the first time by a solvothermal method involving ultrasound assistance which can optimize the rare earth complex dispersibility and achieve strong emission intensity. SiO2@Eu3+@TiO2 core-shell structures were also successfully synthesized by a similar method. Photocatalytic activity analysis showed that the photocatalytic activity factor not only depended on the rare earth ion content, but also related to the structure and size of the TiO2 nanoparticles. Photocatalytic activity increased first and then decreased with the quantity of rare earth ions. Photocatalytic activity was also superior for hollow structures compared to solid structure. Photocatalytic activity of SiO2@TiO2 particles increased with the particle size, until the size increased to 450 nm. Rare earth ions content as well as particle structures and sizes affected efficiency for the photocatalytic degradation of methyl orange. Outstanding photocatalytic activity provides the composite particles with improved potential to purify aquatic contaminants and to meet the demands of future environmental remediation applications.


2008 ◽  
Vol 8 (3) ◽  
pp. 1126-1137 ◽  
Author(s):  
Xueyuan Chen ◽  
Liqin Liu ◽  
Guokui Liu

Research and development of nanoscale luminescent and laser materials are part of the rapidly advancing nanoscience and nanotechnology. Because of unique spectroscopic properties and luminescent dynamics of f-electron states, doping luminescent rare earth ions into nano-hosts has been demonstrated as an optimistic approach to developing highly efficient and stable nanophosphors for various applications. In this article, we review the most recent progress in spectroscopic measurements of rare earth ion-activated low-dimensional nanostructures including nanolayers, core–shells, nanowires, nanotubes, and nanodisks. Among a large volume of work reported in the literature on many members of the rare earth series including Ce3+, Pr3+, Nd3+, Eu3+, and Er3+, we focus on recent findings in the spectroscopic and luminescence properties of Eu3+ doped nanolayers, core–shells, and nanotubes, because Eu3+ ions have been extensively studied and widely used as an ideal probe for fundamental understanding of nano-phenomena. Specifically, the dependence of the optical properties of rare earth ions on nanostructures is discussed in detail.


Cerâmica ◽  
2007 ◽  
Vol 53 (325) ◽  
pp. 79-82 ◽  
Author(s):  
D. M. A. Melo ◽  
M. A .F. Melo ◽  
A. E. Martinelli ◽  
Z. R. Silva ◽  
J. D. Cunha ◽  
...  

Iron oxide has been doped with rare earth ions (yttrium or lanthanum) aiming at producing ceramic pigments with hues that vary from orange to brown. The powders were synthesized from polymeric precursors using the Pechini method and subsequently calcined between 900 and 1100 ºC. The resulting pigments were characterized by BET, X ray diffraction, colorimetric analysis, UV-visible, infrared (FTIR), particle size distribution and thermal analysis. The color depicted by La/Fe powders changed as the calcination temperature increased from 900 ºC to 1100 ºC, as established by the corresponding changes in the values of the colorimetric coordinates from L* a* b* = 49.003, 10.541, 12.609 to L* a* b* = 31.279, 6.096, 6.877. On the other hand, Y/Fe powders were little affected by similar changes in the calcination temperature, revealing the effect of yttrium on the color stability of the powder. The values of the colorimetric coordinates in this case varied from L* a* b* = 45.230, 17.315, 28.750 to L* a* b* =51.631, 15.726, 25.825. Structural changes were also noticed as a function of the size of the rare earth ion added to the structure. Upon calcination at 900°C, lanthanum stabilized the ABO3-type perovskite structure whereas the presence of yttrium resulted in a mixture of oxides.


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