Luminescent Properties of Rare Earth Doped AlF3-Based Glasses

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.

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.


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%.


1996 ◽  
Vol 455 ◽  
Author(s):  
A. Matic ◽  
L. Börjesson ◽  
A. Wannberg ◽  
R. L. McGreevy

ABSTRACTWe have performed neutron scattering experiments on rare-earth (La, Pr, Ho) doped phosphate glasses around the metaphosphate composition R(PO3)3. Combining the diffraction experiment with Reverse Monte Carlo simulations we obtain a 3-D model of the structure. Our models propose a rare-earth ion environment primarily consisting of oxygens with the average rare earth-oxygen distances; 2.56, 2.51 and 2.40 Å for the La, Pr and Ho samples respectively. We also observe that the rare earth ions are not uniformly distributed. The first R-R shell is on avergae about 3.3 Å to be compared with a value of 7 Å for a uniform distribution of R ions in the structure. From the models we also conclude that a chain like structure of the phosphate network is in agreement with the experiment.


2006 ◽  
Vol 518 ◽  
pp. 173-180
Author(s):  
Philippe Goldner ◽  
Olivier Guillot-Noël

Quantum information uses special properties of quantum systems to manipulate or transmit data. This results in new processes, which are impossible to obtain with classical devices. For example, quantum computing and quantum storage, which are two important fields in quantum information research, aim respectively at performing very fast calculations and at storing quantum states of photons. These two applications could be obtained in solid-state systems using rare earth doped crystals. In this context, the most important property of these materials is the long coherence lifetimes of rare earth ion optical and hyperfine transitions. This allows one to create long-lived superposition states, which is a fundamental requirement for efficient quantum computing and storage. Promising results have already been demonstrated in rare earth doped crystals but it will be difficult to improve them with current materials. In this paper, we discuss the general and specific requirements for rare earth ions and crystals in order to perform quantum computing with a large number of quantum bits as well as all solid-state quantum storage. We also present the properties of a few recently studied crystals: Ho3+:YVO4, Ho3+:LuVO4 (quantum computing) and Tm3+:Y3Al5O12 (quantum storage).


1994 ◽  
Vol 358 ◽  
Author(s):  
A.J. Kenyon ◽  
P.F. Trwoga ◽  
M. Federighi ◽  
C.W. Pitt

ABSTRACTWe report the fabrication of rare-earth doped silicon-rich silica thin films by PECVD. The films exhibit absorption edges in the visible region of the optical spectrum consistent with the presence of silicon microclusters. Weak visible photoluminescence due to silicon microclusters is observed. In addition, strong luminescence from the rare-earth ion is obtained even when excited away from characteristic absorption bands; indeed, the luminescence intensity is largely independent of excitation wavelength below 514 nm. We ascribe this to excitation of silicon microclusters followed by an efficient transfer of energy to the rare-earth ions.The very broad absorption of this material opens up the possibility for flashlamp-pumped optoelectronic devices. In addition, we report the fabrication of silicon-rich silica films by PECVD. We show that the optical properties of these films are consistent with the presence of silicon microclusters and show absorption spectra similar to those of the rare-earth doped silicon-rich silica samples. This supports the hypothesis that the principal absorbing species in the rare-earth doped films is microclustered silicon


1986 ◽  
Vol 4 (7) ◽  
pp. 870-876 ◽  
Author(s):  
S. Poole ◽  
D. Payne ◽  
R. Mears ◽  
M. Fermann ◽  
R. Laming

2005 ◽  
Vol 866 ◽  
Author(s):  
G.A. Hirata ◽  
J. Tao ◽  
P. Chen ◽  
K.C. Mishra ◽  
J. McKittrick

AbstractWe report on the fabrication and luminescent properties of rare earth-doped gallium nitride (GaN) phosphor powders. Single phase GaN and GaN:RE3+ powders were prepared by using a novel chemical route.In this work a new method for the synthesis of high purity, single phase doped GaN powders is reported. (Ga1-xREx)N powders are obtained by dissolving metal nitrates (Ga(NO3)3, (RE(NO3)3) in deionized water and an organic fuel (hydrazine) in order to form a gallium/RE amorphous/nanocrystalline powder. The RE-oxide powders are then reacted with heated ammonia at different temperatures and processing times producing GaN:RE phosphors. X-ray diffraction analysis showed that single phase GaN powders are formed. Preliminary results show (Ga0.95Eu0.05)N powders are luminescent, with the main emission occurring at 611 nm which is due to the 5Do→7F2 transitions in Eu3+. High-purity GaN powders are obtained according to Xray photoelectron spectroscopy (XPS) chemical analysis. Low-temperature cathodoluminescence and photoluminescence measurements indicate that the emission at λ=611 nm is originated from energy transfer from the host to the rare earth ion and to a direct excitation to the Eu3+ electronic levels.This method can be used to obtain red-luminescence GaN:Eu3+ and other rare earth (e.g. Er, Tb, Tm)-doped GaN powders to produce green and blue luminescence as well.


2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.


2005 ◽  
Vol 5 (9) ◽  
pp. 1519-1531 ◽  
Author(s):  
Hongwei Song ◽  
Lixin Yu ◽  
LinMei Yang ◽  
Shaozhe Lu

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