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Rare earth excitation

  • Rare-Earth Free Self-Activated Graphene Quantum Dots and

    Oct 09, 2017· Dai, W., Lei, Y., Xu, M. et al. Rare-Earth Free Self-Activated Graphene Quantum Dots and Copper-Cysteamine Phosphors for Enhanced White Light-Emitting-Diodes under Single Excitation.

  • Sensitive detection of excited energy levels in rare-earth

    Sep 09, 2020· An optical method for the sensitive detection of excited energy levels in rare-earth luminescent materials is developed based on the magnetic field induced photoluminescence (PL) enhancement phenomenon observed in Er 3+:YVO 4 crystals. Since the PL intensity of rare-earth luminescent materials is sensitive to the excitation efficiency, continuous tuning of the excitation

  • Excitation and luminescence of rare earth-doped lead

    Mar 16, 2014· Excitation and luminescence properties of rare earth ions in lead phosphate glasses have been studied. The optically active rare earth ions were limited to Eu 3+ , Tb 3+ and Er 3+ . Several registered excitation and luminescence bands correspond to well-known lines characteristic for 4 f 6 4 f 6 (Eu 3+ ), 4 f 8 4 f 8 (Tb 3+ ) and 4 f 11

  • NIR excitation of rare-earth ions in ceramics for

    Jan 01, 2021· Rare-earth doped ceramics and glasses have been known as fluorescent materials for lasers and optical amplifiers. Also, infrared-to-visible upconversion (UC),, to emit visible light with near-infrared (NIR) excitation is a characteristic phenomenon reported mostly for them.

  • The magnetization dynamics of rare-earth metals and the

    Sep 29, 2020· As a result, ultrafast demagnetization of rare-earth metals involves a distinct process in contrast to other elements of the periodic table. During demagnetization of rare-earth

  • Multiphonon relaxation and excitation transfer in rare

    @article{osti_4196590, title = {Multiphonon relaxation and excitation transfer in rare-earth doped glasses}, author = {Layne, Clyde B.}, abstractNote = {Ion of the rare-earth elements retain their discrete electronic energy levels when incorporated into crystalline or glassy host materials. Nonradiative relaxation of excited states of rare-earth ion in glasses and the transfer of excitation

  • Broad excitation of rare earth dopants in chalcogenide

    Photoluminescence excitation (PLE) bands with a width of ~450 nm have been observed which efficiently excite a number of rare earth emission lines. This effect is attributed to the absorption of excitation light by the host glass with the subsequent transfer of energy to the rare earth dopants, mediated by defect states in the glass.

  • 4f Excitation Energies in Rare-Earth Metals: Relativistic

    Feb 19, 2017· Herbst, J. , Watson, R. and Wilkins, J. (1976), 4f Excitation Energies in Rare-Earth Metals: Relativistic Calculations, Physical Review B (Condensed Matter and Materials Physics) (Accessed May 10, 2021)

  • Neodymium - Wikipedia

    Neodymium is a chemical element with the symbol Nd and atomic number 60. Neodymium belongs to the lanthanide series and is a rare-earth element.It is a hard, slightly malleable silvery metal that quickly tarnishes in air and moisture. When oxidized, neodymium reacts quickly to produce pink, purple/blue and yellow compounds in the +2, +3 and +4 oxidation states.

  • Broad band excitation of rare earth emission in

    May 02, 1997· Recent studies of photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopy in rare earth-doped chalcogenide glasses have discovered a novel broad excitation band for the rare earth emissions. This band is attributed to the absorption of light in the Urbach tail of the band edge absorption of the host glass, with a subsequent

  • Whats So Rare About Rare Earth Elements?

    Jul 08, 2013· In fact, the excitation efficiency of a 50kV tube in measuring rare earth elements versus x-ray tubes with a lower voltage have shown conclusively that the lower kV tubes are generally unsuitable for this application. 50 kV tube -based analyzers can analyze light REEs including La, Ce, Pr and Nd.

  • Analysis of the electron excitation spectra in heavy rare

    398 we could select characteristic metallic spectra to perform the calculation of various dielectric or optical parameters. In fact, because of their external electron confi- guration (5d 1 6s2), the heavy rare earth materials (which are the goal of the present investigation) are expected to exhibit rather similar excitation spectra to those observed in scandium and yttrium.

  • The excitation mechanism of rare-earth ions in silicon

    A detailed investigation on the excitation mechanisms of rare-earth (RE) ions introduced in Si nanocrystals (nc) is reported. Silicon nanocrystals were produced by high-dose 80-keV Si implantation in thermally grown SiO 2 followed by 1100 °C annealing for 1 h. Subsequently some of the samples were implanted by 300-keV Er, Yb, Nd, or Tm at doses in the range 2×10<SUP>12</SUP>-3×10<SUP>15

  • Energy Transfer between Gd3+ and Other Rare-earth Ions in

    Jun 09, 2004· Under 172 nm light excitation, energy transfer from Pr 3+, Nd 3+, Tb 3+ or Tm 3+ to Gd 3+ resulting in strong Gd 3+ emission at 312 nm was observed in GdPO 4 doped with one of these ions. Among them, Pr 3+ provides the strongest Gd 3+ emission and Tm 3+ is the second best. A wide energy gap between the 5d state and 4f levels of Pr 3+ resulting from a simple electron configuration of 4f 2

  • NIR excitation of rare-earth ions in ceramics for

    Jan 01, 2021· 1. Introduction. Rare-earth doped ceramics and glasses have been known as fluorescent materials for lasers and optical amplifiers .Also, infrared-to-visible upconversion (UC) , , to emit visible light with near-infrared (NIR) excitation is a characteristic phenomenon reported mostly for them. As for biological use, by making the materials into nanoparticles, UC bioimaging was reported by a

  • Linkage of oxygen deficiency defects and rare earth

    Jun 18, 2012· For both Yb and Er-doped fibers, the dependence of Type II ODC absorption on the rare earth number density is approximately linear, but the magnitude of the effect is greater for Yb-doped fibers. Furthermore, laser excitation spectra demonstrate unambiguously the existence of an energy transfer mechanism coupling an ODC with Yb(3+).

  • Magnetoelastic excitation spectrum in the rare-earth

    in rare-earth pyrochlores is typically attributed to very small levels of off stoichiometry [26], and detailed experimental work on samples in which the exact stoichiometry is varied according to Tb 2+xTi 2xO 7+y [35,2733] suggests that for a small range of 0.05 x 0.04, a phase transition that is

  • The excitation mechanism of rare-earth ions in silicon

    Jul 01, 1999· Rare-earth excitation can quantitatively be described by an effective cross section σ eff taking into account all the intermediate steps leading to excitation. We have directly measured σ eff for Er in Si nc obtaining a value of 2×10 17 cm 2.

  • Study of oblate nuclear shapes and shape coexistence in

    coexistence in the neutron-deficient rare earth region at the ISOLDE facility by employing Coulomb excitation of rare earth beams from the REX accelerator. The isotopes in the region of interest can be produced e.g. by fragmentation of a Ta target by high-energy protons.

  • Rare-earth-doped biological composites as in vivo

    Jul 22, 2013· Recent evidence suggests that rare-earth nanomaterials (REs) are also capable of generating SWIR emissions with large Stokes shifts following excitation with low power, continuous wave sources in

  • Rare-earth-doped nanocrystalline silicon: excitation and

    Excitation and de-excitation mechanisms of rare earth doped nanocrystalline silicon and its implications for waveguide amplifier applications are investigated. Er, Nd, and Pr doped silicon rich silicon oxide (SRSO) thin films were prepared by electron cyclotron resonance enhanced chemical vapor deposition with co-sputtering of target and subsequent anneal at 950 degrees C. Temperature and

  • Developing electric motors less dependable on rare earth

    Jan 22, 2020· The global rare-earth reserves consist of approximately 85 percent LRE and 15 percent HRE. The latter are the ones providing magnets rated at high temperature that are suitable in many automotive applications, as expressed by electronicdesign. And the reality is that, in 2018, 93 percent of all the EVs produced in the world had a

  • Near infrared excitation and emission in rare earth MOFs

    An isoreticular series of anionic rare earth MOFs with fcu topology was synthesized using 10 different rare earth elements (Y 3+, Eu 3+, Gd 3+, Tb 3+, Dy 3+, Ho 3+, Er 3+, Tm 3+, Yb 3+, Lu 3+) and common linear ditopic ligands. Five different cationic dye

  • Photoluminescence studies of rare earth (Er, Eu, Tm) in

    Photoluminescence studies of rare earth (Er, Eu, Tm) in situ doped GaN band-gap excitation the Er3+ PL emission reached its max-imum under slightly N-rich growth conditions. On the con-trary, the band-edge emission from the GaN host reached its maximum

  • Excitation Path of Rare Earth Ions in Nitride Semiconductors

    excitation the exact nature of the excitation path leading to the excitation of rare-earth ions in GaN leads to think that Eu takes the substitutional site of the Gallium. The most commonly assumed mechanism involves Eu-defect complexes where the defect captures an electron-hole pair before Eu excitation.

  • COULOMB EXCITATION IN ODD-A RARE-EARTH NUCLEI by

    the process of E2 Coulomb excitation with heavy ions, in order to ascertain the presence or absence of the specific anticipated perturbations of the rotational motion among the odd-A rare- earth nuclei, and to identify and study experimentally such other features, especially the vibrational states, as

  • The excitation mechanisms of rare earth emissions in the

    Apr 08, 2020· Rare earth excitation mechanisms 87 2.2. Stokes excited emission magnetic dipole transition. This is a direct consequence of the nature of the site that the ion occupies in the thioindate lattice. This means, therefore, that the only emission that can

  • Europium - Wikipedia

    Only 0.2% of the rare-earth element content is europium. The second large source for rare-earth elements between 1965 and its closure in the late 1990s was the Mountain Pass rare earth mine in California. The bastnäsite mined there is especially rich in the light rare-earth elements (La-Gd, Sc, and Y) and contains only 0.1% of europium.

  • Rare earth luminescence: A way to overcome concentration

    Oct 11, 2012· A model is developed to simulate the rare earth luminescence intensity in dependence of both the excitation rate and the dopant concentration. For low excitation rates, as in the case of photoluminescence investigations, concentration quenching is expected. In contrast for high excitation rates (as generally realized in cathodoluminescence experiments) concentration quenching can be

  • Luminescence excitation mechanisms of rare earth doped

    Feb 10, 1999· New technologies are now emerging where rare earth activators are applied in the VUV and XUV excitation energy range and concern the lighting with the development of new Hg-free fluorescent lamps and colour plasma display panels where VUV light from a Penning mixture of xenon and neon excites phosphors deposited on special glass screens.

  • The magnetization dynamics of rare-earth metals and the

    Sep 29, 2020· Rare-earth magnetism is dominated by localized 4f electrons, relative to inner transition metals (that are mostly comprised of lanthanides) and cannot be

  • The excitation mechanism of rare-earth ions in silicon

    A detailed investigation on the excitation mechanisms of rare-earth (RE) ions introduced in Si nanocrystals (nc) is reported. Silicon nanocrystals were produced by high-dose 80-keV Si implantation in thermally grown SiO 2 followed by 1100 °C annealing for 1 h. Subsequently some of the samples were implanted by 300-keV Er, Yb, Nd, or Tm at doses in the range 2×10<SUP>12</SUP>-3×10<SUP>15

  • THE VISIBLE REGION ABSORPTION SPECTRA OF RARE

    Certain rare-earth elements, notably neodymium, praseodymium, erbium, and holm-ium, produce absorption bands in the visible region of the spectrum when present as trivalent ions in solutions or compounds In crystalline minerals these bands may be almost linelike and have a distribution pattern that is influenced by structure, composition, and

  • Spectroscopy of Rare Earth Doped Glasses.

    I.1 RARE EARTH than the excitation frequency. ELEMENTS. I.1 RARE EARTH ELEMENTS REE can be found as divalent, trivalent or tetravalent. For optics, the trivalent lanthanides are the revelant ions, whose electronics distribution is as follows: La and Lu closed outer shell (N= 0 and 14)

  • Excitation and De-Excitation Mechanisms of Rare-Earth Ions

    Excitation and De-Excitation Mechanisms of Rare-Earth Ions in III-V Compounds: Optically Detected Microwave-Induced Impact Ionization of Yb Dopant in Inp - Volume 301

  • Ultraviolet absorption and excitation spectroscopy of rare

    Ultraviolet absorption and laser excitation spectroscopy (LES) measurements are presented for rare-earth-doped optical fibers produced from both glassy and crystalline preforms. Absorption spectra are obtained via broad-spectrum UV LEDs emitting in the 250nm region.