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Sample records for dy er yb

  1. Magnetic-luminescent YbPO4:Er,Dy microspheres designed for tumor theranostics with synergistic effect of photodynamic therapy and chemotherapy.

    Science.gov (United States)

    Wang, Wei; Xu, Dong; Wei, Xiaojun; Chen, Kezheng

    2014-01-01

    In this paper, magnetic and fluorescent bifunctional YbPO4:Er,Dy microspheres were synthesized via a simple solvothermal method. The prepared microspheres exposed to 980 nm near-infrared (NIR) laser light emitted bright upconversion fluorescence (450-570 nm) after calcination at high temperatures (>800°C). Results of magnetic resonance studies demonstrated that the YbPO4:Er,Dy microspheres are more suitable to be used as a transverse relaxation time (negative) contrast magnetic resonance imaging agent. The microspheres successfully entered the human hepatocellular carcinoma cells and presented low toxicity. A well-selected photodynamic therapy (PDT) drug, merocyanine 540 (MC540) with an ultraviolet-visible spectroscopy absorption maximum of 540 nm, was loaded onto the microspheres to obtain YbPO4:Er,Dy-MC540. Since the upconversion fluorescence emitting from the microspheres could be absorbed by MC540 with a small absorption/emission disparity, YbPO4:Er,Dy-MC540 could kill the hepatocellular carcinoma cells via PDT mechanism effectively. In other words, being upconverting particles, the prepared microspheres acted as light transducers in the NIR light-triggered PDT process. A chemotherapy drug, doxorubicin, was further loaded onto YbPO4:Er,Dy-MC540 to achieve enhanced antitumor effect based on synergistic therapeutic efficacy of PDT and chemotherapy. It is expected that the prepared YbPO4:Er,Dy microspheres have applications in tumor theranostics including magnetic-fluorescent bimodal imaging and NIR light-triggered PDT.

  2. Strong broad green UV-excited photoluminescence in rare earth (RE = Ce, Eu, Dy, Er, Yb) doped barium zirconate

    Energy Technology Data Exchange (ETDEWEB)

    Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro, Qro. 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Ciudad de Mexico, D. F. 07730 (Mexico); Meza, O. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico)

    2011-10-25

    Highlights: > Trivalent rare earth (RE) substitution on Zr{sup 4+} sites in BaZrO{sub 3} lead to band gap narrowing. > RE substitution lead to enhanced blue-green intrinsic emission of nanocrystalline BaZrO{sub 3} > Blue-green hue of BaZrO3:RE depends on RE dopant and excitation UV wavelength > BaZrO3: Dy{sup 3+} PL chromatic coordinates correspond to pure white color coordinates of CIE 1931 model - Abstract: The wet synthesis hydrothermal method at 100 deg. C was used to elaborate barium zirconate (BaZrO{sub 3}) unpurified with 0.5 mol% of different rare earth ions (RE = Yb, Er, Dy, Eu, Ce). Morphological, structural and UV-photoluminescence properties depend on the substituted rare earth ionic radii. While the crystalline structure of RE doped BaZrO{sub 3} remains as a cubic perovskite for all substituted RE ions, its band gap changes between 4.65 and 4.93 eV. Under 267 nm excitation the intrinsic green photoluminescence of the as synthesized BaZrO{sub 3}: RE samples is considerably improved by the substitution on RE ions. For 1000 deg. C annealed samples, under 267 nm, the photoluminescence is dominated by the intrinsic BZO emission. It is interesting to notice that Dy{sup 3+}, Er{sup 3+} and Yb{sup 3+} doped samples present whitish emissions that might be useful for white light generation under 267 nm excitation. CIE color coordinates are reported for all samples.

  3. Structural and magnetic phase transitions of kagome-like compounds REBaCo{sub 4}O{sub 7} (RE=Dy, Ho, Er, Tm, Yb, Lu)

    Energy Technology Data Exchange (ETDEWEB)

    Markina, M., E-mail: markina@lt.phys.msu.r [Low Temperature Physics Department, Moscow State University, Moscow 119992 (Russian Federation); Vasiliev, A.N. [Low Temperature Physics Department, Moscow State University, Moscow 119992 (Russian Federation); Nakayama, N.; Mizota, T. [Department of Advanced Materials Science and Engineering, Faculty of Engineering, Yamaguchi University, Ube 755-8611 (Japan); Yeda, Y. [Materials Design and Characterization Laboratory, Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581 (Japan)

    2010-05-15

    In a temperature range 5-300 K the specific heat C(T) on a new mixed valence cobalt oxides REBaCo{sub 4}O{sub 7} (RE=Dy, Ho, Er, Tm, Yb, Lu) was investigated. The first-order structural phase transitions from hexagonal P6{sub 3}mc to orthorhombic Cmc{sub 2}1 phase was indicated by a peak-like anomaly in C(T) curves at T{sub S}approx160, 178, 224, and 280 K for RE=Lu, Yb, Tm, and Er correspondingly. The magnetic phase transitions was indicated as the changes of slope on the C(T) curves were found at corresponding temperatures: T{sub N}approx50, 74, 98, and 98 K for RE=Lu, Yb, Tm, and Er, correspondingly.

  4. Measurement of formation cross sections of short-lived nuclei by 14 MeV neutron. Nd, Sm, Dy, Er, Yb

    Energy Technology Data Exchange (ETDEWEB)

    Sakane, H.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan). School of Engineering; Iida, T.; Takahashi, A.

    1997-03-01

    Eight neutron activation cross sections producing the nuclei with half-lives between 3 min and 24 min were obtained at the energy range between 13.4 and 14.9 MeV by activation method. The cross sections were {sup 146}Nd(n,p){sup 146}Pr, {sup 154}Sm(n,{alpha}){sup 151}Nd, {sup 162}Dy(n,p){sup 162}Tb, {sup 163}Dy(n,np){sup 162}Tb, {sup 163}Dy(n,p){sup 163}Tb, {sup 164}Dy(n,p){sup 164}Tb, {sup 170}Er(n,{alpha}){sup 167}Dy, {sup 174}Yb(n,p){sup 170}Tm. {sup 163}Dy(n,np){sup 162}Tb (T{sub 1/2}=7.7 min) was obtained for the first time. Present results are compared with previous results and the evaluated data of JENDL-3 and ENDF/B-VI. There are some discrepancies between present results and the JENDL-3 and ENDF/B-VI. (author)

  5. Triple-layered perovskite niobates CaRNb3O10 (R = La, Sm, Eu, Gd, Dy, Er, Yb, or Y): new self-activated oxides.

    Science.gov (United States)

    Qin, Lin; Wei, Donglei; Huang, Yanlin; Kim, Sun Il; Yu, Young Moon; Seo, Hyo Jin

    2013-09-16

    Niobates CaRNb3O10 (R = La, Sm, Eu, Gd, Dy, Er, Yb, or Y) were prepared by conventional high-temperature solid-state reaction. The formation of a single-phase compound with triple-layered perovskite-type structure was verified through X-ray diffraction (XRD) studies. The luminescence characteristics such as photoluminescence excitation and emission spectra, X-ray-excited luminescence (XEL), Stokes shift, decay curves, and color coordinates were investigated. The niobates can be efficiently excited by UV light and present luminescence behaviors with rich luminescence colors. Under excitation by ultraviolet radiation, CaRNb3O10 (R = La, Gd, Yb, or Y) exhibits strong blue luminescence due to the self-activation center of the octahedral NbO6 groups, even at room temperature. For the materials of composition CaRNb3O10 (R = Sm, Eu, Dy, or Er), the excitation at the host band produces a characteristic luminescence of rare earth ions, indicating a host-guest energy transfer process. CaRNb3O10 (R = Eu) has the strongest luminescence intensity, which can be efficiently excitated by near UV wavelength. It could be suggested to be a potential candidate for the application on near-UV excited white LEDs.

  6. Pico- and subpicosecond relaxation processes in lanthanide-porphyrin complexes. [Lanthanoids: Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu

    Energy Technology Data Exchange (ETDEWEB)

    Solov' ev, K.N.; Tsvirko, M.P.; Krasauskas, V.V.; Pyatosin, V.E.; Stel' makh, G.F.

    1984-03-01

    Methods of nano- and picosecond absorption spectroscopy and luminescence are used to determine the deactivation rates of ..pi.., ..pi..*-electron states of S/sub 2/, S/sub 1/ and T/sub 1/ in complexes of organic molecules of meso-tetratolylporphyne and tetrabenzoporphyne with trivalent Sm/sup 3 +/, Eu/sup 3 +/, Gd/sup 3 +/, Tb/sup 3 +/, Dy/sup 3 +/, Ho/sup 3 +/, Er/sup 3 +/, Tm/sup 3 +/, Yb/sup 3 +/, Lu/sup 3 +/. Quantitative data on superfast relaxation processes in lanthanide porphyrines are obtained. The function of the metal entral ion is presented in details as the excitation factor in deactivation processes of photoexcitation energy of the systems in question.

  7. Structural and thermoelectric properties of BaRCo{sub 4}O{sub 7} (R = Dy, Ho, Er, Tm, Yb, and Lu)

    Energy Technology Data Exchange (ETDEWEB)

    Wong-Ng, W.; Yan, Y.; Liu, G. [Ceramics Division, NIST, Gaithersburg, Maryland 20899 (United States); Xie, W.; Tritt, T. [Department of Physics, Clemson University, Greensville, South Carolina 29634 (United States); Kaduk, J. [Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Thomas, E. [Air Force Research Laboratory, Wright Pattersen, Ohio 45433 (United States)

    2011-12-01

    The structure and thermoelectric properties of a series of barium lanthanide cobaltites, BaRCo{sub 4}O{sub 7} (R = Dy, Ho, Er, Tm, Yb, and Lu), which were prepared using the spark plasma synthesis technique, have been investigated. The space group of these compounds was re-determined and confirmed to be P31c instead of the reported P6{sub 3}mc. The lattice parameters a and c range from 6.26279(2) Angst to 6.31181(6) Angst , and from 10.22468(6) Angst to 10.24446(15) Angst for R = Lu to Dy, respectively. The crystal structure of BaRCo{sub 4}O{sub 7} is built up from Kagome sheets of CoO{sub 4} tetrahedra, linked by triangular layers of CoO{sub 4} tetrahedra. The values of figure of merit (ZT) of the BaRCo{sub 4}O{sub 7} samples were determined to be around 0.02 at 800 K. X-ray diffraction patterns of these samples have been determined and submitted to the Powder Diffraction File.

  8. Structural and magnetic properties of two branches of the tripod-kagome-lattice family A2R3Sb3O14 (A = Mg, Zn; R = Pr, Nd, Gd, Tb, Dy, Ho, Er, Yb)

    Science.gov (United States)

    Dun, Z. L.; Trinh, J.; Lee, M.; Choi, E. S.; Li, K.; Hu, Y. F.; Wang, Y. X.; Blanc, N.; Ramirez, A. P.; Zhou, H. D.

    2017-03-01

    We present a systematic study of the structural and magnetic properties of two branches of the rare-earth tripod-kagome-lattice (TKL) family A2R3Sb3O14 (A = Mg, Zn; R = Pr, Nd, Gd, Tb, Dy, Ho, Er, Yb; here, we use abbreviation A-R, as in MgPr for Mg2Pr3Sb3O14 ), which complements our previously reported work on MgDy, MgGd, and MgEr [Z. L. Dun et al., Phys. Rev. Lett. 116, 157201 (2016), 10.1103/PhysRevLett.116.157201]. The present susceptibility (χdc, χac) and specific-heat measurements reveal various magnetic ground states, including the nonmagnetic singlet state for MgPr, ZnPr; long-range orderings (LROs) for MgGd, ZnGd, MgNd, ZnNd, and MgYb; a long-range magnetic charge ordered state for MgDy, ZnDy, and potentially for MgHo; possible spin-glass states for ZnEr, ZnHo; the absence of spin ordering down to 80 mK for MgEr, MgTb, ZnTb, and ZnYb compounds. The ground states observed here bear both similarities as well as striking differences from the states found in the parent pyrochlore systems. In particular, while the TKLs display a greater tendency towards LRO, the lack of LRO in MgHo, MgTb, and ZnTb can be viewed from the standpoint of a balance among spin-spin interactions, anisotropies, and non-Kramers nature of single-ion state. While substituting Zn for Mg changes the chemical pressure, and subtly modifies the interaction energies for compounds with larger R ions, this substitution introduces structural disorder and modifies the ground states for compounds with smaller R ions (Ho, Er, Yb).

  9. Structural Study of a Doubly Ordered Perovskite Family NaLnCoWO6 (Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb): Hybrid Improper Ferroelectricity in Nine New Members.

    Science.gov (United States)

    Zuo, Peng; Colin, Claire V; Klein, Holger; Bordet, Pierre; Suard, Emmanuelle; Elkaim, Erik; Darie, Céline

    2017-07-17

    The compounds of the doubly ordered perovskite family NaLnCoWO6 (Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Yb) were synthesized by solid-state reaction, nine of which (Ln = Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Yb) are new phases prepared under high-temperature and high-pressure conditions. Their structural properties were investigated at room temperature by synchrotron X-ray powder diffraction and neutron powder diffraction. All of them crystallize in monoclinic structures, especially the nine new compounds have the polar space group P21 symmetry, as confirmed by second harmonic generation measurements. The P21 polar structures were decomposed and refined in terms of symmetry modes, demonstrating that the polar mode is induced by two nonpolar modes in a manner of Hybrid Improper Ferroelectricity. The amplitudes of these three major modes all increase with decreasing the Ln cation size. The spontaneous ferroelectric polarization is estimated from the neutron diffraction data of three samples (Ln = Y, Tb, and Ho) and can be as large as ∼20 μC/cm(2).

  10. Correlation between slow magnetic relaxation and the coordination structures of a family of linear trinuclear Zn(II)-Ln(III)-Zn(II) complexes (Ln = Tb, Dy, Ho, Er, Tm and Yb).

    Science.gov (United States)

    Maeda, Moe; Hino, Shiori; Yamashita, Kei; Kataoka, Yumiko; Nakano, Motohiro; Yamamura, Tomoo; Kajiwara, Takashi

    2012-11-28

    Six linear trinuclear [Ln{Zn(L)(AcO)}(2)]BPh(4) complexes (H(2)L denotes the Schiff-base ligand formed by a condensation reaction between ethylenediamine and two equivalents of o-vanillin), including Ln = Tb (1), Dy (2), Ho (3), Er (4), Tm (5) and Yb (6) were synthesized and were confirmed to be isostructural via X-ray crystallographic analyses. The Ln(III) ion in each complex is deca-coordinated by four equatorial oxygen donors from the methoxo groups of the Schiff-base ligands, two oxygen donors from the acetate anions and four axial oxygen donors from the phenoxo groups of the Schiff-base ligands. AC susceptibility measurements, with an oscillating frequency of 10 to 10,000 Hz, revealed that 1, 2, 4 and 6 show slow magnetic relaxation under a 1000 Oe DC bias field, which occurs via a single process, as confirmed by the semi-circular Cole-Cole plots. These complexes are considered to be field-induced single-molecule magnets under these conditions. The presence or absence of the slow magnetic relaxation process is discussed by correlating the characteristic magnetic anisotropy of each Ln(III) ion with the ligand field anisotropy.

  11. Syntheses, structures, and magnetic properties of a family of heterometallic heptanuclear [Cu5Ln2] (Ln = Y(III), Lu(III), Dy(III), Ho(III), Er(III), and Yb(III)) complexes: observation of SMM behavior for the Dy(III) and Ho(III) analogues.

    Science.gov (United States)

    Chandrasekhar, Vadapalli; Dey, Atanu; Das, Sourav; Rouzières, Mathieu; Clérac, Rodolphe

    2013-03-04

    Sequential reaction of the multisite coordination ligand (LH3) with Cu(OAc)2·H2O, followed by the addition of a rare-earth(III) nitrate salt in the presence of triethylamine, afforded a series of heterometallic heptanuclear complexes containing a [Cu5Ln2] core {Ln = Y(1), Lu(2), Dy(3), Ho(4), Er(5), and Yb(6)}. Single-crystal X-ray crystallography reveals that all the complexes are dicationic species that crystallize with two nitrate anions to compensate the charge. The heptanuclear aggregates in 1-6 are centrosymmetrical complexes, with a hexagonal-like arrangement of six peripheral metal ions (two rare-earth and four copper) around a central Cu(II) situated on a crystallographic inversion center. An all-oxygen environment is found to be present around the rare-earth metal ions, which adopt a distorted square-antiprismatic geometry. Three different Cu(II) sites are present in the heptanuclear complexes: two possess a distorted octahedral coordination sphere while the remaining one displays a distorted square-pyramidal geometry. Detailed static and dynamic magnetic properties of all the complexes have been studied and revealed the single-molecule magnet behavior of the Dy(III) and Ho(III) derivatives.

  12. Synthesis and Characterization of Ethylthioethylcyclopentadienyl Organolanthanide Complexes:Cp2Th LnCl (Ln=Gd, Dy), Cp2LnCpTh (Ln=Yb, Sm, Dy, Y) and Cp2ThErCl2·2THF

    Institute of Scientific and Technical Information of China (English)

    ZHU Ming朱铭; ZHANG Li-Bei张丽蓓; CHEN Ying-Hua陈应华; ZHOU Xi-Geng周锡庚; CAI Rui-Fang蔡瑞芳; WENG Lin-Hong翁林红

    2004-01-01

    Six new ethylthioethylcyclopentadienyl-containing organolanthanide complexes Cp2Th LnCl [Ln=Gd (1), Dy (2)]and Cp2LnCpTh [Cp=C5H5, Ln=Yb (3), Sm (4), Dy (5), Y (6)] were synthesized by the reaction of ethylthioethylcyclopentadienyl (CpTh) sodium salt with LnC13 or Cp2LnCl in THF. Complexes 1-6 were characterized by elemental analyses, infrared and mass spectroscopies. The molecular structures of complexes 1-3 were also determined by the X-ray single crystal diffraction. The results show that the side-chain sulfur atom on the ethylthioethylcyclopentadienyl ring can form intramolecular chelating coordination to the central lanthanide ion, improving the stability of organolanthanide complexes and reducing the number of coordinated THF molecules.

  13. Efficient ultraviolet-blue to near-infrared downconversion in Bi-Dy-Yb-doped zeolites

    Science.gov (United States)

    Bai, Zhenhua; Fujii, Minoru; Hasegawa, Takashi; Imakita, Kenji; Mizuhata, Minoru; Hayashi, Shinji

    2011-11-01

    Ultraviolet-blue to near-infrared (NIR) downconversion is investigated for the Dy3+-Yb3+ couple in zeolites by steady-state and time-resolved photoluminescence (PL) spectra, and PL excitation spectra. Upon excitation of the 4F9/2 level of Dy3+, NIR quantum cutting could occur through a two-step energy transfer from one Dy3+ ion to two neighbouring Yb3+ ions via an intermediate level. The energy transfer efficiency from the 4F9/2 level is estimated to be 42%, and the intrinsic PL quantum efficiency of Yb3+ emission reaches 54%. The findings may have potential application in enhancing the energy efficiency of silicon-based solar cells.

  14. Er3+-Yb3+ codoped borosilicate glass for optical thermometry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Infrared to green up-conversion emissions centered at the wavelengths of about 524 and 550 nm of the Er3+-Yb3+ codoped borosilicate glass are recorded,using a 978 nm semiconductor laser diode(LD) as an excitation source.The fluorescence intensity ratio(FIR) of the green up-conversion emissions at about 524 and 550 nm in the Er3+-Yb3+ codoped borosilicate glass has been studied as a function of temperature over the temperature range of 295-873 K.The maximum sensitivity and the temperature resolution derived from the FIR of the green up-conversion emissions are approximately 0.0038 K-1 and 0.2 K,respectively.It is demonstrated that the prototype optical temperature sensor based on the FIR technique from the green up-conversion emissions in the Er3+-Yb3+ codoped borosilicate glass plays a major role in temperature measurement.

  15. Yb3+ Ion Upconversion Luminescence from YbEr:ZBLAN Glass Excited by 966 nm Laser Light

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-Bo; NIE Yu-Xin; WEN Ou

    2001-01-01

    The upconversion lumiuescence of several YbEr co-doped Zr-Ba-La-AI-Na (ZBLAN) glass samples (Er(0.5) Yb(3): ZBLAN, Er(0.5)Yb(1):ZBLAN and Er(0.5):ZBLAN) has been studied. A new kind of upconversion cooperative radiation fluorescence, which comes from coupled cluster states of two Yb3+ ions has been observed. This is significant in that it may lead to a new path to achieve blue upconversion luminescence, which has promising upconversion applications.

  16. [Direct upconversion sensitization luminescence comparison of the ErYb co-doped oxyfluoride fluoride pentaphosphate glass].

    Science.gov (United States)

    Chen, Xiao-bo; Chen, Luan; Zhao, Chen-yi; Sawanobori, N; Ma, Hui; Song, Zeng-fu

    2003-02-01

    This paper investigates the direct upconversion sensitization luminescence of the ErYb co-doped oxyfluoride glass (ErYb: FOG), fluoride glass (ErYb: ZBLAN) and pentaphosphate noncrystalline (ErYb: PP) excited by a 966 nm diode laser. The splendid upconversion luminescence phenomenon is found. It is resulted from that the Yb3+ concentration in rather high, the energy transfer among Er(3+)-Yb3+ and Yb(3+)-Yb3+ ions is rather strong. An important fact is found that the direct upconversion sensitization luminescence of ErYb: FOG is about 100-100,000 times greater than that of ErYb: PP. And meanwhile it is interesting that the upconversion luminescence intensity of ErYb: FOG is near to that of ErYb: ZBLAN. It is significant to enhance the comprehensive level of up-conversion luminescence.

  17. Lattice dynamics of rare-earth titanates with the structure of pyrochlore R 2Ti2O7 ( R = Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu): Ab initio calculation

    Science.gov (United States)

    Chernyshev, V. A.; Petrov, V. P.; Nikiforov, A. E.

    2015-05-01

    The ab initio calculation has been performed for the crystal structure and the phonon spectrum of titanates with the structure of pyrochlore R 2Ti2O7 ( R = Gd-Lu). The frequencies and types of fundamental vibrations have been found. For R = Tb, Tm, and Yb, this calculation has been carried out for the first time; furthermore, there is no available information on experimental studies of the phonon spectrum for Tm and Yb. The influence of hydrostatic pressure to 35 GPa on the structure, dynamics, and elastic properties of the Gd2Ti2O7 lattice has been investigated. The dependence of the phonon frequencies on the pressure has been obtained. The calculations have predicted that the relative change in the pyrochlore structure volume during compression at pressures to 35 GPa is well described by the third-order Birch-Murnaghan equation of states. The results of the calculations agree with the available experimental data. It has been shown that the structural, dynamic, and elastic properties of the R 2Ti2O7 crystal lattice can be adequately described in the case where the inner shells of the RE ion up to 4 f are replaced by the pseudopotential.

  18. Yb~(3+)/Er~(3+)-Codoped Tungsten-Tellurite Glasses for Broadband Optical Amplifier

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Emission spectra and fluorescence lifetime of Er3+ in Yb3+/Er3+-codoped tungsten-tellurite glasses were measured. Effects of Yb3+concentration on 1.5μm emission intensity and bandwidth of Er3+ were investigated and a FWHM of 81 nm was demonstrated.

  19. Structural and optical studies of Yb3+, Er3+ and Er3+/Yb3+ co-doped phosphate glasses

    Institute of Scientific and Technical Information of China (English)

    S.Hraiech; M.Ferid; Y.Guyot; G.Boulon

    2013-01-01

    Phosphate glass samples with various Yb2O3 and Er2O3 contents were synthesized by the conventional melt quenching technique and characterized by X-ray diffraction,IR absorption spectroscopy and Raman scattering spectroscopy.The absorption,emission spectra and fluorescence decay studies were carried out both at low and room temperatures.Results showed the existence of several sites occupied by the rare earth ions in the phosphate glass.Up-conversion and cooperative fluorescence were also discussed.

  20. Antireflective downconversion ZnO:Er3+,Yb3+ thin film for Si solar cell applications

    Science.gov (United States)

    Elleuch, R.; Salhi, R.; Deschanvres, J.-L.; Maalej, R.

    2015-02-01

    Hexagonal wurtzite phased ZnO:Er3+/Yb3+ thin films with various Yb concentrations were deposited on Si(111) substrate by Aerosol Assisted Chemical Vapor Deposition process. Post-annealed films at 1000 °C in air atmosphere showed a crystallinity enhancement. Yb3+ (4F7/2 → 4F5/2) 1000 nm emission increased with the increase of Yb3+ concentration emanating from an Er-Yb energy transfer. The reflectance percentage of 12% was achieved in the [250-1000 nm] range, and the refractive index of 1.97 was obtained for 632 nm wavelength. These results suggest that the (3 mol. % Er, 9 mol. % Yb) codoped film is a highly efficient antireflective downconversion layer for enhancing Si solar cell efficiency.

  1. Beta-Decay Study of ^{150}Er, ^{152}Yb, and ^{156}Yb: Candidates for a Monoenergetic Neutrino Beam Facility

    Energy Technology Data Exchange (ETDEWEB)

    Estevez Aguado, M. E. [CSIC-Universidad de Valencia; Algora, A. [CSIC-Universidad de Valencia; Rubio, B. [CSIC-Universidad de Valencia; Bernabeu, J. [CSIC-Universidad de Valencia; Nacher, E. [CSIC-Universidad de Valencia; Tain, J. L. [CSIC-Universidad de Valencia; Gadea, A. [CSIC-Universidad de Valencia; Agramunt, J. [CSIC-Universidad de Valencia; Burkard, K. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Hueller, W. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Doring, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kirchner, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mukha, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Plettner, C. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Roeckl, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Grawe, H. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Collatz, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Hellstrom, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Cano-Ott, D. [CIEMAT, Madrid; Karny, M. [University of Warsaw; Janas, Z. [University of Warsaw; Gierlik, M. [University of Warsaw; Plochocki, A. [University of Warsaw; Rykaczewski, Krzysztof Piotr [ORNL; Batist, L. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Moroz, F. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Wittman, V. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Blazhev, A. [University of Cologne; Valiente, J. J. [INFN, Laboratori Nazionali di Legnaro, Italy; Espinoza, C. [CFPT-IST, Lisbon

    2011-01-01

    The beta decays of ^{150}Er, ^{152}Yb, and ^{156}Yb nuclei are investigated using the total absorption spectroscopy technique. These nuclei can be considered possible candidates for forming the beam of a monoenergetic neutrino beam facility based on the electron capture (EC) decay of radioactive nuclei. Our measurements confirm that for the cases studied, the EC decay proceeds mainly to a single state in the daughter nucleus.

  2. Up-Conversion Emission of Er3+ Ions in Yb3+ Sensitized Oxide Crystals

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Ruan Yongfeng; Lin Junyi; Liu Jian; Huang Boxian

    2004-01-01

    Most of the up-conversion lasers operated at room temperature are realized with heavy metal fluorides, In this paper the Judd-Ofelt parameters Ωλ ( λ = 2,4,6 ) were calculated for Er3+ ions in Yb3 + sensitized LiNbO3 and YVO4 crystals at room temperature, together with the radiative transition probabilities, non-radiative transition probabilities and resonant transition probabilities of Er3+ ions. Taking into account the energy transfer from Yb3 + to Er3 +, the rate equations are given for Er3 + ions. We obtained from a solution of the rate equations that Yb3 + sensitized YVO4 crystal is more efficient than Yb3 + sensitized LiNbO3 crystal in the up-conversion of 550 nm of Er3+ emission, which is consistent with our observation.

  3. Structural and photoluminescence properties of Ce, Dy, Er-doped ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jayachandraiah, C. [Department of Physics, JNTU, Anantapur-515002 (India); Kumar, K. Siva [Department of Advanced Materials Science and Engineering, Dankook University, Cheonan, Chungnam 330-714 (Korea, Republic of); Krishnaiah, G., E-mail: ginnerik@gmail.com [Govt. Degree College, Puttur, Chittoor-517 583 (India)

    2015-06-24

    Undoped ZnO and rare earth elements (Ce, Dy and Er with 2 at. %) doped nanoparticles were synthesized by wet chemical co-precipitation method at 90°C with Polyvinylpyrrolidone (PVP) as capping agent. The structural, morphological, compositional and photoluminescence studies were performed with X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energy dispersive spectroscopy (EDS), FTIR spectroscopy and Photoluminescence (PL) respectively. XRD results revealed hexagonal wurtzite structure with average particle size around 18 nm - 14 nm and are compatible with TEM results. EDS confirm the incorporation of Ce, Dy and Er elements into the host ZnO matrix and is validated by FTIR analysis. PL studies showed a broad intensive emission peak at 558 nm in all the samples. The intensity for Er- doped ZnO found maximum with additional Er shoulder peaks at 516nm and 538 nm. No Ce, Dy emission centers were found in spectra.

  4. Thermodynamic assessment of the Bi–Er and the Bi–Dy systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jinsan [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Li, Changrong, E-mail: crli@mater.ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Guo, Cuiping; Du, Zhenmin [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Wu, Bo [School of Materials Science and Engineering, Fuzhou University, Fuzhou 350100 (China)

    2013-08-20

    Highlights: • The Bi–Er and Bi–Dy binary systems were optimized. • The first-principles method was used to calculate formation enthalpies of compounds. • A self-consistent set of thermodynamic parameters were obtained. • The experimental and calculated data were well reproduced by the optimized results. - Abstract: Based on the available experimental data, the Bi–Er and the Bi–Dy binary systems have been assessed thermodynamically using the CALPHAD (CALculaton of PHAse Diagram) technique. The formation enthalpies at 0 K of the compounds, Bi{sub 3}Er{sub 5}, BiEr, Bi{sub 3}Dy{sub 5} and BiDy, were calculated by the first-principles method and Birch–Murnaghan equation of state, and the calculated results were used in the present thermodynamic optimization. All these compounds in the Bi–Er and the Bi–Dy systems were treated as stoichiometric compounds. The liquid phase was modeled as a substitutional solution phase based on random mixing of the constituent atoms and the excess Gibbs energy was formulated with the Redlich–Kister polynomial. Good agreements were obtained between the calculated results and the experimental data for both the thermochemical properties and the phase equilibrium relations.

  5. Magnetic remanence in Yb14-xRExMnSb11 (RE=Tb, Dy, Ho) single crystals

    Science.gov (United States)

    Grebenkemper, Jason H.; Hu, Yufei; Abdusalyamova, M. N.; Makhmudov, F. A.; Kauzlarich, Susan M.

    2016-06-01

    Single crystals of Yb14-xRExMnSb11 (x~0.1, 0.4; RE = Tb, Dy, Ho) have been prepared as a solid solution by Sn flux reactions of the elements. They crystallize in the Ca14AlSb11 structure type in the I41/acd space group. The RE3+preferentially substitutes on the Yb(1) site which is the smallest volume Yb containing polyhedron. In the case of Ho3+, a small amount of Ho3+ also substitutes on the Yb(4) site. The ferromagnetic ordering temperature of Yb14MnSb11 is reduced from 53 K to 41 K as x increases and dependent on the identity of the RE. This is attributed to the reduction in carriers and reduced screening of the Mn2+ local moment. The effective moments, μeff, agree well with the calculated moments assuming the RE substitutes as a trivalent cation. The largest coercive field is observed for RE = Dy (1000 Oe). For the maximum x of Yb14-xRExMnSb11 there are enough carriers for the Ruderman-Kittel-Kasuya-Yosida (RKKY) mechanism of magnetic coupling via conduction electrons to still be valid in describing the ferromagnetic ordering.

  6. Green up-converted luminescence in (Er3+-Yb3+) co-doped LiNbO3 crystals

    Science.gov (United States)

    Stoffel, M.; Rinnert, H.; Kokanyan, E.; Demirkhanyan, G.; Demirkhanyan, H.; Aillerie, M.

    2016-07-01

    Er3+ doped and (Er3+-Yb3+) co-doped LiNbO3 (LN) crystals grown by the Czochralski method are investigated by photoluminescence spectroscopy. Green up-converted luminescence is observed in Er3+ doped LN crystals under 980 nm excitation. This is explained by an energy transfer between two neighboring Er3+ ions. In (Er3+, Yb3+) co-doped LN crystals, the intensity of the green up-converted luminescence can be further enhanced suggesting that Yb3+ ions also contribute to the up-conversion process. Time resolved photoluminescence measurements clearly demonstrate that an efficient energy transfer occurs between Yb3+ and Er3+ ions. A theoretical model taking into account the contribution of both Er3+-Er3+ pairs and Yb3+-Er3+ pairs is able to describe correctly the decay of the up-converted luminescence.

  7. Modeling of Yb3+-sensitized Er3+-doped silica waveguide amplifiers

    DEFF Research Database (Denmark)

    Lester, Christian; Bjarklev, Anders Overgaard; Rasmussen, Thomas

    1995-01-01

    A model for Yb3+-sensitized Er3+-doped silica waveguide amplifiers is described and numerically investigated in the small-signal regime. The amplified spontaneous emission in the ytterbium-band and the quenching process between excited erbium ions are included in the model. For pump wavelengths...... between 860 and 995 nm, the amplified spontaneous emission in the ytterbium-band is found to reduce both the gain and the optimum length of the amplifier significantly. The achievable gain of the Yb3+-sensitized amplifier is found to be higher than in an Er3+-doped silica waveguide without Yb 3+ (18 d...

  8. Preparation and up-conversion luminescence properties of LaOBr:Yb3+/Er3+ nanofibers via electrospinning.

    Science.gov (United States)

    Ma, Wenwen; Yu, Wensheng; Dong, Xiangting; Wang, Jinxian; Liu, Guixia

    2014-11-01

    LaOBr:Yb(3+)/Er(3+) nanofibers were synthesized for the first time by calcinating electrospun PVP/[La(NO3)3 + Er(NO3)3 + Yb(NO3)3 + NH4 Br] composites. The morphology and properties of the final products were investigated in detail using scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray diffractometry (XRD) and fluorescence spectroscopy. The results indicate that LaOBr:Yb(3+)/Er(3+) nanofibers are tetragonal in structure with a space group of P4/nmm. The diameter of LaOBr:Yb(3+)/Er(3+) nanofibers is ~ 147 nm. Under the excitation of a 980-nm diode laser, LaOBr:Yb(3+)/Er(3+) nanofibers emit strong green and red up-conversion emission centering at 519, 541 and 667 nm, ascribed to the (2)H11/2, (4)S3/2 → (4) I(15/2) and (4)F9/2 → (4)I(15/2) energy-level transitions of Er(3+) ions, respectively. The up-conversion luminescent mechanism of LaOBr:Yb(3+)/Er(3+) nanofibers is advanced. Moreover, near-infrared emission of LaOBr:Yb(3+)/Er(3+) nanofibers is obtained under the excitation of a 532-nm laser. The formation mechanism of LaOBr:Yb(3+)/Er(3+) nanofibers is proposed. LaOBr:Yb(3+)/Er(3+) nanofibers could be important up-conversion luminescent materials.

  9. Effects of Yb3+ codoping on visible and near infrared emissions of Er3+-Yb3+ codoped AI203 powders by the sol-sol method

    Institute of Scientific and Technical Information of China (English)

    DONG Bin; SUN Min; FENG ZhiOing; SONG ZhaoYuan; LIU XiaoDong

    2008-01-01

    The 0.1 mol% Er3+ and 0-2 mol% Yb3+ codoped AI2O3 powders were prepared by the sol-gel method, and the phase structure, including only two crystalline types of doped AI2O3 phase, γ-(AI,Er, Yb)2O3 andO-(AI,Er, Yb)2O3, was detected at the sintering temperature of 1000. The visible and near infrared emissions properties depended strongly on the Yb3+ codoping, and the corresponding maximal peak intensities centered at about 523, 545, 660 and 1533 nm were obtained respectively for the 0.1 mol% Er3+ and 0.5 mol% Yb3+ codoped AI2O3 powders, which were composed of 0-(AI,Er, Yb)O3 and a smallamount of γ-(AI,Er, Yb)2O3 phases. The two-photon absorption process was responsible for the visible up-conversion emissions, and the one-photon absorption process was involved in the near infrared emissions of the Er3+-Yb3+ codoped AI2O3 powders.

  10. Optical bistability in Er-Yb codoped phosphate glass microspheres at room temperature

    NARCIS (Netherlands)

    Warda, Jonathan M.; O'Shea, Danny G.; Shortt, Brian J.; Chormaic, Sile Nic

    2007-01-01

    We experimentally demonstrate optical bistability in Er(3+)-Yb(3+) phosphate glass microspheres at 295 K. Bistability is associated with both Er(3+) fluorescence and lasing behavior, and chromatic switching. The chromatic switching results from an intrinsic mechanism exploiting the thermal coupling

  11. Ion-exchanged waveguide lasers in Er3+/Yb3+ codoped silicate glass.

    Science.gov (United States)

    Peters, P M; Funk, D S; Peskin, A P; Veasey, D L; Sanford, N A; Houde-Walter, S N; Hayden, J S

    1999-11-20

    We investigated an Er(3+)/Yb(3+) codoped silicate glass as a host material for waveguide lasers operating near 1.5 microm. Spectroscopic properties of the glass are reported. Waveguide lasers were fabricated by K(+)-ion exchange from a nitrate melt. The waveguides support a single transverse mode at 1.5 microm. An investigation of the laser performance as a function of the Yb:Er ratio was performed, indicating an optimal ratio of approximately 5:1. Slope efficiencies of as great as 6.5% and output powers as high as 19.6 mW at 1.54 microm were realized. The experimental results are compared with a waveguide laser model that is used to extract the Er(3+) upconversion coefficients and the Yb(3+)-Er(3+) cross-relaxation coefficients. The results indicate the possibility of obtaining high-performance waveguide lasers from a durable silicate host glass.

  12. Modeling the absorption spectra of Er3+ and Yb3+ in a phosphate glass

    Science.gov (United States)

    Gruber, John B.; Sardar, Dhiraj K.; Zandi, Bahram; Hutchinson, J. Andrew; Trussell, C. Ward

    2003-10-01

    Absorption spectra of Er3+ and Yb3+ ions, codopants in a phosphate glass, are reported at 8 K and at wavelengths between 350 and 1600 nm. Detailed structure appearing in the spectra, associated with individual multiplet states, 2S+1LJ, of Er3+(4f11) and Yb3+(4f13) is interpreted using a ligand-field coordination sphere model to characterize the microscopic environment surrounding the rare earth ions in multiple sites. Inhomogeneous broadening of the spectra is likely due to different configurations of PO4 tetrahedra clustered about a caged rare earth ion in the amorphous host. Similarity between the Er3+ spectrum in the glass and in the spectrum of single-crystal LiErP4O12, where Er3+ occupies sites of C2 symmetry, suggests that an averaged site symmetry of C2 is a reasonable approximation for Er3+ and Yb3+ ions in the phosphate glass. Calculated splitting of multiplet states by the ligand-field cluster model are compared with energy levels derived from the observed absorption peaks and well-defined shoulders. Inhomogeneous broadening of the spectra limit the precision in establishing the energy of the multiplet splittings, but the analysis is useful for modeling studies of the Er:Yb:phosphate glass as an eye-safe laser (1.53 μm). The splitting of the Yb3+(4f13)2FJ states is determined using parameters obtained from the Er3+ set by means of the three-parameter theory. No adjustments were made to the Yb3+ parameters that predict multiplet splittings in reasonable agreement with experimental data.

  13. Crystal fields of dilute Tb, Dy, or Er in Sc obtained by magnetization measurements

    DEFF Research Database (Denmark)

    Høg, J.; Touborg, P.

    1976-01-01

    Crystal-field parameters for dilute Sc-Tb, Sc-Dy, and Sc-Er alloys have been obtained by fitting theoretical expressions to the experimentally measured paramagnetic susceptibility. The initial susceptibility was measured and corrected for the effects of ordering at the lowest temperatures in the ...

  14. Visible upconversion in Er3+/Yb3+ co-doped LaAlO3 phosphors

    Science.gov (United States)

    Singh, Vijay; Rai, V. K.; Singh, N.; Pathak, M. S.; Rathaiah, M.; Venkatramu, V.; Patel, Rahul V.; Singh, Pramod K.; Dhoble, S. J.

    2017-01-01

    The Er3+ doped and Er3+/Yb3+ co-doped LaAlO3 phosphors have been synthesized by the combustion method and characterized their structural, morphological, elemental, vibrational and optical properties. The optical absorption and upconversion properties of the synthesized phosphors have been studied. Upon co-doping Yb3+ ions into Er3+:LaAlO3, the blue, green and red upconversion emissions of Er3+ ions have been enhanced about 20, 54 and 22 times, under 978 nm laser excitation. The observed upconversion emissions could be due to excited state absorption in Er3+:LaAlO3, whereas energy transfer is dominant mechanism in Er3+/Yb3+:LaAlO3 phosphors. The tuning in the color emitted from the synthesized phosphors towards the green region has been found due to incorporation of the Yb3+ ions. With increase in the pump power, the color emitted from the co-doped phosphor is not tuned significantly, showing its applicability in making the green display devices.

  15. Preparation, characterization and optical properties of ZrO2:Er3+, Yb3+ nanomaterials

    Science.gov (United States)

    Thu Huong, Tran; Thanh Huong, Nguyen; Thi Kieu Giang, Lam; Anh, Tran Kim; Lojkowski, Witold; Minh, Le Quoc

    2009-09-01

    Luminescent nanomaterials from lanthanide are one of most promising materials for applications in medical diagnostics. In this paper, we present for the first time the ZrO2 nanomaterials with capsule like nanostructure with the sizes of 150 nm in length and 50 nm in width. These nanocapsule like ZrO2 doped with Er3+, Yb3+ ions were prepared by soft template methods. Morphological characterization of nano - ZrO2:Er3+, Yb3+ was performed by using FESEM, X-ray diffraction, micro Raman. Up conversion luminescence and photoluminescence have been also studied with IR-laser excitation at 940 nm and UV excitation at 365 nm.

  16. Photoluminescence characterization of porous YAG: Yb{sup 3+}–Er{sup 3+} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Desirena, H., E-mail: hagdes@cio.mx [Centro de Investigaciones en Óptica, A. P. 1-948, León 37150, Guanajuato (Mexico); Diaz-Torres, L.A. [Centro de Investigaciones en Óptica, A. P. 1-948, León 37150, Guanajuato (Mexico); Rodríguez, R.A. [Centro Universitario de Los Lagos, Universidad de Guadalajara, Lagos de Moreno, Jalisco (Mexico); Meza, O. [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado Postal J-48, Centro Historico 72570, Puebla (Mexico); Salas, P. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Apartado Postal 1-1010, Querétaro 76000, Querétaro México (Mexico); Angeles-Chávez, C. [Instituto Mexicano del Petróleo, Ciudad México, D.F. 07730, México (Mexico); Tobar, E.H.; Castañeda-Contreras, J. [Centro Universitario de Los Lagos, Universidad de Guadalajara, Lagos de Moreno, Jalisco (Mexico); De la Rosa, E., E-mail: elder@cio.mx [Centro de Investigaciones en Óptica, A. P. 1-948, León 37150, Guanajuato (Mexico)

    2014-09-15

    Yb{sup 3+}/Er{sup 3+} codoped yttrium aluminium garnet (YAG) porous nanocrystals were prepared by glycolate method assisted with poly-vinyl alcohol (PVA) and urea. The typical cubic structure for YAG was confirmed from XRD with crystallite average size of ∼40 nm, calculated from Scherrer formula and corroborated by TEM. Strong green and red upconversion emissions are observed readily with the naked eyes, and the color coordinates were obtained from emission spectra. A theoretical model to calculate CIE coordinate as a function of donor (Yb{sup 3+}) and acceptors (Er{sup 3+}) concentration is proposed. The eye-safe near infrared emitted signal and fluorescence lifetime were also measured and results show lifetime as large as 8.5 ms. The maximum energy transfer efficiency from Yb{sup 3+} to Er{sup 3+} was 72% for 20 mol% of Yb{sub 2}O{sub 3}. The proposed mechanisms for signal emitted are explained in terms of direct and energy back transfer processes, and cross relaxation. - Highlights: • Strong upconversion emission were observed in YAG:Er{sup 3+}–Yb{sup 3+} samples. • Color emission can be tuned from green to red by choosing properly the Yb{sup 3+} concentration. • The experimental colour coordinates match very well with the proposed theoretical model. • Cross relaxation and energy back transfer are mainly responsible for the red emission. • Fluorescence lifetime of {sup 4}I{sub 13/2} level increase with the Yb{sup 3+} concentration.

  17. Measurement of cross sections producing short-lived nuclei by 14 MeV neutron. Br, Te, Dy, Ho, Yb

    Energy Technology Data Exchange (ETDEWEB)

    Sakane, H.; Matsumoto, T.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.

    1997-03-01

    Nine neutron activation cross sections producing the nuclei with half-lives between 2 min and 57 min have been measured at energy range between 13.4 and 14.9 MeV for Br, Te, Dy, Ho, Yb. The cross sections of {sup 81}Br(n,p){sup 81m}Se, {sup 128}Te(n,p){sup 128m}Sb, {sup 128}Te(n,{alpha}){sup 125m}Sn, {sup 164}Dy(n,p){sup 164}Tb, {sup 165}Ho(n,{alpha}){sup 162}Tb, {sup 176}Yb(n,p){sup 176}Tm were newly obtained at the six energy points between 13.4-14.9 MeV, although the previous results have been obtained at one energy point. {sup 79}Br(n,2n){sup 78}Br, {sup 164}Dy(n,p){sup 164}Tb are compared with evaluated data of JENDL-3.2. The evaluations for these reactions agree reasonably well with experimental results. The cross sections of (n,p) reaction are compared with systematics by Kasugai et. al. The systematics agrees with experimental results. (author)

  18. Intense up-conversion luminescence in Er3+/Yb3+ co-doped CeO2 powders.

    Science.gov (United States)

    Singh, Vijay; Rathaiah, M; Venkatramu, V; Haase, Markus; Kim, S H

    2014-03-25

    The Er(3+) and Er(3+)/Yb(3+) co-doped CeO2 powders have been prepared by a urea combustion route. The structural, morphological, compositional and vibrational analysis of the Er(3+):CeO2 and Er(3+)/Yb(3+):CeO2 powders have been studied by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray and Fourier transform infrared spectroscopy. The optical and luminescence properties of Er(3+):CeO2 and Er(3+)/Yb(3+):CeO2 powders have been studied by using laser excited spectroscopy. The effects of Yb(3+) doping on up-conversion luminescence of Er(3+) co-doped CeO2 powders were studied. The ratio of red to green intensity is decreased in Er(3+):CeO2 whereas the ratio is increased in Er(3+)/Yb(3+):CeO2 powders with increase of power. The effect of co-doping with the Yb(3+) ions on the visible luminescence of Er(3+) and the energy transfer mechanism responsible for the variation in the green and red intensity are discussed. The results indicate that these materials may be suitable for display and light emitting devices.

  19. The normal and inverse magnetocaloric effect in RCu2 (R=Tb, Dy, Ho, Er) compounds

    Science.gov (United States)

    Zheng, X. Q.; Xu, Z. Y.; Zhang, B.; Hu, F. X.; Shen, B. G.

    2017-01-01

    Orthorhombic polycrystalline RCu2 (R=Tb, Dy, Ho and Er) compounds were synthesized and the magnetic properties and magnetocaloric effect (MCE) were investigated in detail. All of the RCu2 compounds are antiferromagnetic (AFM) ordered. As temperature increases, RCu2 compounds undergo an AFM to AFM transition at Tt and an AFM to paramagnetic (PM) transition at TN. Besides of the normal MCE around TN, large inverse MCE around Tt was found in TbCu2 compound. Under a field change of 0-7 T, the maximal value of inverse MCE is even larger than the value of normal MCE around TN for TbCu2 compound. Considering of the normal and inverse MCE, TbCu2 shows the largest refrigerant capacity among the RCu2 (R=Tb, Dy, Ho and Er) compounds indicating its potential applications in low temperature multistage refrigeration.

  20. Nanocrystal formation and photoluminescence in the Yb3+/Er3+ codoped phosphosilicate glasses

    DEFF Research Database (Denmark)

    Liu, S.J.; Fu, G.Z.; Shan, Z.T.

    2014-01-01

    In the paper we show that the Yb3+/Er3+ codoped transparent nanocrystal containing phosphosilicate glasses can be obtained by the melt-quenching devitrification approach. We find that the type of alkali oxides has a strong impact on the crystallization in phosphosilicate melts during cooling. The...

  1. Er3+/Yb3+ Codoped Phosphate Glass for Ion-Exchanged Planar Waveguide Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Shilong Zhao; Baoyu Chen; Zhuping Liu; Lili Hu

    2003-01-01

    A novel Er3+/Yb3+ codoped phosphate glass was developed, which exhibited good chemical durability in molten salts and excellent spectroscopic properties. Preliminary results of ion exchange at different time and temperature, and with varying melt concentrations indicated that WM4 glass was suitable for ion-exchange experiments and there was no deterioration of surface quality.

  2. Er~(3+)/Yb~(3+) Codoped Phosphate Glass for Ion-Exchanged Planar Waveguide Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel Er3+/Yb3+ codoped phosphate glass was developed, which exhibited good chemical durability in molten salts and excellent spectroscopic properties. Preliminary results of ion exchange at different time and temperature, and with varying melt concentrations indicated that WM4 glass was suitable for ion-exchange experiments and there was no deterioration of surface quality.

  3. Effect of the concentration of the dopants (Er3 +, Yb3 + and Zn2 +) and temperature on the upconversion emission behavior of Er3 +/Yb3 + co-doped SrAl2O4 phosphor

    Science.gov (United States)

    Choudhary, Ajay Kumar; Dwivedi, A.; Bahadur, A.; Rai, S. B.

    2017-10-01

    Er3 +/Yb3 + co-doped SrAl2O4 (SRA: Er3 +, Yb3 +) phosphor has been synthesized by high temperature solid state reaction technique. The pure phase formation has been confirmed by X-ray diffraction (XRD) measurements. The surface morphology is studied by scanning electron microscopy (SEM) technique. The FTIR measurements give the information of vibrational bands arising due to sample. The intense UC emission from SRA: Er3 +, Yb3 + phosphor has been monitored on excitation with 980 nm diode laser. The SRA: Er3 +, Yb3 + samples prepared at 1473 K show a dominant green emission. On the other hand it shows dominant red emission when the sample is heated to 1623 K. Variation of concentration of Er3 + and Yb3 + ions in SRA: Er3 +, Yb3 + phosphor suggests two possible mechanisms involved in UC emission process viz. cross relaxation (CR) process and energy back transfer (EBT) process, respectively. The cross relaxation mechanism seems to play a major role. The UC emission efficiency is enhanced several times on co-doping of Zn2 + ion replacing Al3 + or Sr2 + in SRA: Er3 +, Yb3 + phosphor sample. The color of the UC emission can be tuned from green to red region by varying the concentration of zinc.

  4. Energy transfer mechanism in Yb{sup 3+}:Er{sup 3+}-ZBLAN: macro- and micro-parameters

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Z. E-mail: zmengjp@yahoo.co.jp; Nagamatsu, K.; Higashihata, M.; Nakata, Y.; Okada, T. E-mail: okada@ees.kyushu-u.ac.jp; Kubota, Y.; Nishimura, N.; Teshima, T.; Buddhudu, S

    2004-04-01

    Dynamics of forward energy transfer and backward energy transfer processes in fluorozirconate glass doubly doped with Yb{sup 3+} and Er{sup 3+} have been explained by 'rate equation' and 'fluorescence transfer function' models. From the rate equation analysis, macroscopic energy transfer parameters, the cross-relaxation coefficients, were determined to be 1.36x10{sup -17} and 3.38x10{sup -17} s{sup -1} cm{sup 3} for the forward energy transfer (Yb{sup 3+}{yields}Er{sup 3+}) and the backward transfer (Er{sup 3+}{yields}Yb{sup 3+}), respectively. Based on the fluorescence 'transfer-function' model, the kinetics of the energy transfer processes between Yb{sup 3+} and Er{sup 3+} ions has been analyzed, and the microscopic energy transfer parameters of the Yb:Er-codoped system, the critical radii, were derived as 13.0 and 18.0 A for the donor-acceptor (Yb{sup 3+}{yields}Er{sup 3+}) and the acceptor-donor (Er{sup 3+}{yields}Yb{sup 3+}), respectively. The 1.55 {mu}m band emission property of the rare-earth-codoped fluoride glass systems has been discussed.

  5. The influence of silver ion exchange on the luminescence properties of Er-Yb silicate glasses

    Science.gov (United States)

    Stanek, S.; Nekvindova, P.; Svecova, B.; Vytykacova, S.; Mika, M.; Oswald, J.; Barkman, O.; Spirkova, J.

    2017-10-01

    A set of zinc-silicate glasses with different ratios of Er-Yb as well amount of Zn was fabricated. The preparation of silver doped glasses was carried out using the Ag-Na ion-exchange method to enhance Er-Yb luminescence properties of the material. The samples were also annealed for 1-5 h to further support the creation of silver nanoparticles. Intensive absorption at 980 nm was observed in absorption spectra after ion exchange and annealing as well. Also luminescence spectra in the near-infrared range were measured and results showed positive effect of ion exchange process on luminescence properties. Luminescence intensity at 1530 nm was increased almost three times. Possible mechanisms responsible for the increase of the luminescence intensity are also discussed in this paper. We suggest that the enhancement of erbium luminescence intensity is caused by the energy transfer from isolated Ag+ ions to Er.

  6. Synthesis and Upconversion Luminescence of LaF3: Yb3+, Er3+/SiO2 Core/Shell Microcrystals

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    LaF3: Yb3+, Er3+ microcrystals were synthesized by a hydrothermal method, and then, the LaF3: Yb3+, Er3+ microcrystals were coated with silica. Phase identification of LaF3: Yb3+, Er3+ and LaF3: Yb3+, Er3+/SiO2 was performed via XRD. The TEM image showed that the size of LaF3: Yb3+, Er3+ was 150 nm and LaF3: Yb3+, Er3+/SiO2 presented clearly a core/shell structure with 20 nm shell thickness. The upconversion spectra of LaF3: Yb3+, Er3+ and LaF3: Yb3+, Er3+/SiO2 in solid state and in ethanol were studied with a 980 nm diode laser as the excitation source. The upconversion spectra showed that the silica shell had little effect on the properties of fluorescence of the LaF3: Yb3+, Er3+ microcrystals. At the same time, the green luminescence photo of LaF3: Yb3+, Er3+/SiO2 in the PBS buffer was obtained, which indicated that the LaF3: Yb3+, Er3+/SiO2 could be used in biological applications.

  7. Broadband Quantum Cutting in ZnO/Yb(Er)F3 Oxy-Fluoride Nanocomposite Prepared by Thermal Oxidation Method

    Science.gov (United States)

    Zhang, Wentao; Xiao, Siguo; Yang, Xiaoliang; Jin, Xiangliang

    2013-02-01

    Yb(Er)F3 nanoparticles absorbed with ZnO sheet were prepared via two-step co-precipitation method followed with thermal oxidation. In the ZnO/Yb(Er)F3 composite phosphor, ZnO can efficiently absorb ultraviolet photons of 250-380 nm and transfer its absorbed photon energy to Er3+ ions in fluoride particles. A followed quantum cutting between Er3+-Yb3+ couples in the fluoride takes place, down-converting an absorbed ultraviolet photon into two photons of 650 nm and 980 nm radiations. The composite phosphor combines the wide wavelength absorption range and high absorption cross-section of ZnO with high quantum cutting efficiency of Er3+-Yb3+ co-doped fluoride, showing potential application in the enhancement of Si solar cell efficiency.

  8. [The upconversion "characteristic saturation phenomenon" of ErYb:ZBLAN glass excited by 966 nm diode laser].

    Science.gov (United States)

    Chen, X; Li, M; Hao, Z; Meng, G; Song, Z

    2001-06-01

    This paper researches the upconversion luminescence of Er:ZBLAN and ErYb:ZBLAN glasses excited by 966 nm diode laser. It is found that there is a new kind of "characteristic saturation phenomenon". It is that the log-log plot's slope of upconversion luminescence intensity upon laser power of ErYb:ZBLAN glass is decreased clearly than that of Er:ZBLAN, and both of their log-log plots are rather good straight line. This upconversion mechanism is a new kind of "diffusion-transfer" mechanism, that is energy diffusion among Yb3+ ions sequential followed by energy transfer between Er(3+)-Yb3+ ions. The "characteristic saturation phenomenon" is just resulted from energy diffusion.

  9. Optical temperature sensing properties of Yb3+/Er3+ codoped LaF3 upconversion phosphor

    Science.gov (United States)

    Cheng, Xuerui; Ma, Xiaochun; Zhang, Huanjun; Ren, Yufen; Zhu, Kunkun

    2017-09-01

    The structural and optical properties of Er3+/Yb3+ codoped LaF3 phosphors are investigated using X-ray diffraction (XRD) and upconversion luminescence spectra. The result shows that the hexagonal phase of LaF3 keep stability at temperature lower than 800 °C in air condition and will be oxidized to be LaOF at higher temperature. Its upconversion emission intensity varies with the doping concentrations of Yb3+ ions and reaches a maximum at around 7 mol% Yb3+. The power-dependent luminescence reveals the possible emission mechanisms and the corresponding upconversion processes. Furthermore, the optical temperature sensing properties of LaF3: Er3+/Yb3+ are studied based on the fluorescence intensity ratio (FIR) technique for two thermally coupled levels (2H11/2 and 4S3/2) of Er3+. The maximum sensitivity is found to be about 0.00157 K-1 at 386 K, revealing this phosphor to be a promising prototype for applications in optical temperature sensing.

  10. Intrinsic single-band upconversion emission in colloidal Yb/Er(Tm):Na3Zr(Hf)F7 nanocrystals.

    Science.gov (United States)

    Chen, Daqin; Lei, Lei; Zhang, Rui; Yang, Anping; Xu, Ju; Wang, Yuansheng

    2012-11-07

    Novel Yb/Er(Tm):Na(3)MF(7) (M = Zr, Hf) nanocrystals with intrinsic single-band upconversion emission, in contrast to the routine lanthanide-doped fluoride nanocrystals which show typical multi-band upconversion emissions, are reported for the first time. Specifically, the red upconversion intensity of the Yb/Er:Na(3)ZrF(7) nanocrystals is about 5 times as high as that of the hexagonal Yb/Er:NaYF(4) ones with a similar crystal size.

  11. Synthesis, Structural Characterization and Up-Conversion Luminescence Properties of NaYF4:Er3+,Yb3+@MOFs Nanocomposites

    Science.gov (United States)

    Giang, Lam Thi Kieu; Marciniak, Lukasz; Huy, Tran Quang; Vu, Nguyen; Le, Ngo Thi Hong; Binh, Nguyen Thanh; Lam, Tran Dai; Minh, Le Quoc

    2017-10-01

    This paper describes a facile synthesis of NaYF4:Er3+,Yb3+ nanoparticles embraced in metal-organic frameworks (MOFs), known as NaYF4:Er3+, Yb3+@MOFs core/shell nanostructures, by using iron(III) carboxylate (MIL-100) and zeolitic imidazolate frameworks (ZIF-8). Morphological, structural and optical characterization of these nanostructures were investigated by field emission-scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, and up-conversion luminescence measurements. Results showed that spherical-shaped NaYF4:Er3+,Yb3+@MIL-100 nanocomposites with diameters of 150-250 nm, and rod-shaped NaYF4:Er3+,Yb3+@ZIF-8 nanocomposites with lengths of 300-550 nm, were successfully synthesized. Under a 980-nm laser excitation at room temperature, the NaYF4:Er3+,Yb3+@MOFs nanocomposites exhibited strong up-conversion luminescence with two emission bands in the green part of spectrum at 520 nm and 540 nm corresponding to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of Er3+ ions, respectively, and a red emission band at 655 nm corresponding to the 4F9/2 → 4I15/2 transition of Er3+ ions. The above properties of NaYF4:Er3+,Yb3+@MOFs make them promising candidates for applications in biotechnology.

  12. Synthesis, Structural Characterization, and Emission Properties of NaYF4:Er3+/Yb3+ Upconversion Nanoluminophores

    Science.gov (United States)

    Giang, Lam Thi Kieu; Marciniak, Lukasz; Hreniak, Dariusz; Anh, Tran Kim; Minh, Le Quoc

    2016-10-01

    We propose a new method to prepare Er3+/Yb3+-codoped β-NaYF4 upconversion nanoluminophores, allowing creation of single-crystalline-phase β-NaYF4: Er3+/Yb3+ with concentrations up to 20 mol.% through a hydrothermal process. Using hexagonal-phase Y(OH)3 precursors with different nanostructures (nanosheets, nanorods, nanotubes, etc.), one can obtain many types of one-dimensional nano-NaYF4:Er3+/Yb3+ materials and significantly improve the multiphase phenomenon, which is a common challenge facing many research groups that use a hydrothermal process for synthesis of NaYF4 compounds. Upon near-infrared laser excitation at 976 nm, the obtained β-NaYF4:Er3+/Yb3+ nanorods emit in green (2H11/2, 4S3/2 → 4I15/2) and red (4F9/2 → 4I15/2) spectral regions with high intensity. Moreover, it is shown that one can change the luminescence integrated intensity ratio between the red and green emissions by varying the concentration and components of Er3+ and Yb3+ in the NaYF4 host material. Comparative studies on the luminescence kinetics of the NaYF4:Er3+/Yb3+ nanoluminophores were also conducted to explain the influence of Yb3+ ion on the upconversion processes.

  13. Síntese de ZnAl2O4: Yb:Er por reação de combustão Synthesis of ZnAl2O4: Yb:Er by combustion reaction

    Directory of Open Access Journals (Sweden)

    J. F. Silva

    2006-09-01

    Full Text Available Aluminato de zinco dopado com os íons terras raras itérbio e érbio nas proporções 2:1, 3:1, 4:1, e 5:1 mol de Yb:Er foi sintetizado por reação de combustão. O efeito da dopagem simultânea Yb:Er na estrutura e na morfologia do aluminato de zinco foi investigado. Os pós foram sintetizados com base nos conceitos da química dos propelentes e então caracterizados por difração de raios X, análise granulométrica, adsorção de nitrogênio (método BET e microscopia eletrônica de varredura. Os resultados mostraram a formação da fase cristalina majoritária de ZnAl2O4:Yb:Er e traços das fases secundárias ZnO e Yb2O3 e que o aumento da relação Yb:Er favoreceu o aumento das fases secundárias. Todas as composições apresentaram morfologia formada por aglomerados moles constituídos por partículas finas. A área superficial aumentou em função da elevação da proporção Yb:Er.Zinc aluminate doped with ytterbium and erbium in the proportions 2:1, 3:1, 4:1, and 5:1 mol of Yb:Er were synthesized by combustion reaction. The effect of the Yb:Er in the structure and morphology of the zinc aluminate was investigated. The powders were synthesized on the basis of the propellants chemistry concepts and characterized by X-ray diffraction, nitrogen adsorption (BET method and scanning electron microscopy. The results show the formation of the ZnAl2O4:Yb:Er as majority crystalline phase and traces of ZnO and Yb2O3 as secondary phases, and that the increase of the Yb:Er proportion favored the increase of the content of secondary phases. All the compositions presented morphology formed by soft agglomerates of fine particles. The surface area increases with increasing Yb:Er proportion.

  14. Er-doped and Er, Yb co-doped oxyfluoride glasses and glass-ceramics, structural and optical properties

    Science.gov (United States)

    Lisiecki, Radosław; Augustyn, Elżbieta; Ryba-Romanowski, Witold; Żelechower, Michał

    2011-09-01

    The selected glasses and glass-ceramics pertinent to following chemical composition in mol%:48%SiO 2-11%Al 2O 3-7%Na 2O-10%CaO-10%PbO-11%PbF 2-3%ErF 3 and 48%SiO 2-11%Al 2O 3-7%Na 2O-10%CaO-10%PbO-10%PbF 2-1%ErF 3-3%YbF 3 have been manufactured from high purity components (Aldrich) at 1450 °C in normal atmosphere. Glass optical fibers were successfully drawn. Subsequently they were subject to the heat-treatment at 700 °C in various time periods. The preceding differential thermal analysis (DTA) studies allowed estimating both the fiber drawing temperature and the controlled crystallization temperature of glass fibers. It has been observed that the controlled heat-treatment of oxyfluoride glass fibers results in the creation of Pb 5Al 3F 19, Er 4F 2O 11Si 3 and Er 3FO 10Si 3 crystalline phases. The identified phases were characterized by X-ray powder diffraction (XRD) and confirmed by selected area electron diffraction (SAED). The fibers consist of mixed amorphous-crystalline microstructure with nano-crystals of size even below 10 nm distributed in the glassy host. Their morphology was investigated applying high-resolution transmission electron microscopy. Optical properties and excited state relaxation dynamics of optically active ions (Er 3+, Yb 3+) in glass and glass-ceramics have been studied. Based on absorption spectra the Judd-Ofelt analysis was carried out. The main attention was directed to NIR luminescence at. 1.6 μm related to 4I 13/2 → 4I 15/2 Er 3+ and less effective emission associated with 4I 11/2 → 4I 15/2 Er 3+ and 2F 5/2 → 2F 7/2 Yb 3+ transitions. The dissimilar spectroscopic properties have been revealed for glasses and glass-ceramic samples, respectively. The reduction of emission linewidth at 1.6 and 1.0 μm combined with substantial increase of 4I 13/2 lifetimes of erbium in glass-ceramics appear to be evidences that Er 3+ ions are accommodated in crystalline phases. The structural and optical characteristics of oxyfluoride glass

  15. Crystal growth, structure, and physical properties of Ln(Cu,Al)12 (Ln = Y, Ce, Pr, Sm, and Yb) and Ln(Cu, Ga)12 (Ln = Y, Gd-Er, and Yb).

    Science.gov (United States)

    Drake, Brenton L; Capan, C; Cho, Jung Young; Nambu, Y; Kuga, K; Xiong, Y M; Karki, A B; Nakatsuji, S; Adams, P W; Young, D P; Chan, Julia Y

    2010-02-17

    Single crystals of Ln(Cu,Al)12 and Ln(Cu,Ga)12 compounds (Ln = Y, Ce-Nd, Sm, Gd-Ho, and Yb for Al and Ln = Y, Gd-Er, Yb for Ga) have been grown by flux-growth methods and characterized by means of single-crystal x-ray diffraction, complemented with microprobe analysis, magnetic susceptibility, resistivity and heat capacity measurements. Ln(Cu,Ga)12 and Ln(Cu,Al)12 of the ThMn12 structure type crystallize in the tetragonal I4/mmm space group with lattice parameters a approximately 8.59 Å and c approximately 5.15 Å and a approximately 8.75 Å and c approximately 5.13 Å for Ga and Al containing compounds, respectively. For aluminium containing compounds, magnetic susceptibility data show Curie-Weiss paramagnetism in the Ce and Pr analogues down to 50 K with no magnetic ordering down to 3 K, whereas the Yb analogue shows a temperature-independent Pauli paramagnetism. Sm(Cu,Al)12 orders antiferromagnetically at T(N)approximately 5 K and interestingly exhibits Curie-Weiss behaviour down to 10 K with no Van Vleck contribution to the susceptibility. Specific heat data show that Ce(Cu,Al)12 is a heavy fermion antiferromagnet with T(N) approximately 2 K and with an electronic specific heat coefficient γ0 as large as 390 mJ K2 mol(-1). In addition, this is the first report of Pr(Cu,Al)12 and Sm(Cu,Al)12 showing an enhanced mass (approximately 80 and 120 mJ K(2) mol(-1)). For Ga containing analogues, magnetic susceptibility data also show the expected Curie-Weiss behaviour from Gd to Er, with the Yb analogue being once again a Pauli paramagnet. The antiferromagnetic transition temperatures range over 12.5, 13.5, 6.7, and 3.4 K for Gd, Tb, Dy, and Er. Metallic behaviour is observed down to 3 K for all Ga and Al analogues. A large positive magnetoresistance up to 150% at 9 T is also observed for Dy(Cu,Ga)12. The structure, magnetic, and transport properties of these compounds will be discussed.

  16. Buffer-gas loaded magneto-optical traps for Yb, Tm, Er and Ho

    CERN Document Server

    Hemmerling, Boerge; Chae, Eunmi; Ravi, Aakash; Doyle, John M

    2013-01-01

    Direct loading of magneto-optical traps from a very slow cryogenic buffer-gas beam of lanthanides is achieved and studied, without the need for laser slowing. A collisionally cooled cryogenic atomic source with average forward velocity of 60-70 m/s and a width of ~70 m/s allows for loading without additional dissipation, unlike oven or supersonic sources. The lanthanides Yb, Tm, Er, and Ho are trapped. Despite the He buffer-gas background, we observe a maximum lifetime of about 80 ms (with Yb). We further show that the addition of a single-frequency slowing laser increases the number of trapped Yb atoms by an order of magnitude, yielding a total of 4.0(2) x 10^8. We study decay to metastable states in all species and report decay rates. Extension of this approach to MOTs of molecules is discussed.

  17. A study of the quantum efficiency of multichannel relaxation in LiNbO3:Yb, Er crystals

    Science.gov (United States)

    Stroganova, E. V.; Nalbantov, N. N.; Galutsky, V. V.; Yakovenko, N. A.

    2016-12-01

    Luminescence spectra of gradient-activated LiNbO3:Yb, Er crystals with predefined concentration profiles of the optical centers are studied in different spectral regions. The process of electronic excitation energy transfer in the Yb3+-Er3+ system inside the LiNbO3 matrix is calculated and dependences of the quantum efficiency of the up-conversion processes for the green and red luminescences of erbium ions on the time of excitation energy deactivation are obtained.

  18. Down conversion luminescence behavior of Er and Yb doped Y2O3 phosphor

    Directory of Open Access Journals (Sweden)

    Sadhana Agrawal

    2014-10-01

    Full Text Available We have studied downconversion luminescence behaviour of Y2O3 phosphor doped with Er 1 mol% and 1 mol% of Yb. The sample was prepared by modified solid state reaction method. Using inorganic material like (Y2O3, Flux Calcium Fluoride (CaF2 and Er2O3 as well as Yb2O3 with molar ratio 1 mol% of dopant. The prepared phosphor sample was characterized using Powder X-Ray Diffraction (PXRD, Field Emission Gun Scanning Electron Microscopy (FEGSEM, High Resolution Transmission Electron Microscopy (HRTEM, Photoluminescence (PL, Thermoluminescence (TL and CIE techniques. The obtained sample shows an intense greenish-white emission (ranging from 350 to 600 nm, centered at 565 nm under a wide range of UV light excitation (220–400 nm.

  19. Sequential growth of sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles for photodynamic therapy

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Huang-Yong; Ding, Bin-Bin; Ma, Yin-Chu [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Sun, Shi-Qi [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Tao, Wei [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Guo, Yan-Chuan [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Guo, Hui-Chen, E-mail: ghch-2004@hotmail.com [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Yang, Xian-Zhu, E-mail: yangxz@hftu.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Qian, Hai-Sheng, E-mail: shqian@hfut.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China)

    2015-12-01

    Graphical abstract: The monodisperse elliptical NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles have been synthesized successfully by a facile sequential growth process, which can be used as transducer for photodynamic therapy of cancer cells. - Highlights: • The NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb nanoparticles have been fabricated successfully. • The as-prepared nanoparticles show strong fluorescence excited at 980 or 808 nm. • The nanoparticles were transferred into the aqueous phase via a facile process. • Photosensitizers were loaded into the composites for photodynamic therapy. - Abstract: Upconversion (UC) nanostructures have attracted much interest for their extensive biological applications. In this work, we describe a sequential synthetic route to prepare sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles. The as-prepared products were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM, JEM 2100F), respectively. The as-prepared core–shell nanoparticles of NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb are composed of elliptical nanoparticles with a length of 80 nm and width of 42 nm, which show efficient upconversion fluorescence excited at 808 nm indicating the formation of core–shell–shell sandwiched nanostructures. In addition, the as-prepared sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles also show strong upconversion fluorescence excited at 980 nm. Amphiphilic mPEG{sub 2k}-b-PEBEP{sub 6K} copolymers (denoted as PPE) were chosen to transfer these hydrophobic UCNPs into the aqueous phase for biological application. In vitro photodynamic therapy of cancer cells show that the viability of cells incubated with the nanoparticles loaded with MC 540 was significantly lower as compared to the nanoparticles without photosensitizers exposed to NIR laser.

  20. Superconducting Dy1-x(Gd,Yb)xBa2Cu3O7-δ thin films made by Chemical Solution Deposition

    DEFF Research Database (Denmark)

    Opata, Yuri Aparecido; Wulff, Anders Christian; Hansen, Jørn Otto Bindslev

    2016-01-01

    Dy1-x(Gd or Yb)xBa2Cu3O7-δ samples were prepared using chemical solution deposition (CSD), based on trifluoroacetate metal-organic decomposition (MOD) methods. X-ray diffraction results demonstrated the formation of the RE123 superconducting phase with a strong in-plane and out-of-plane texture. c...

  1. Syntheses, Structure, Magnetism, and Optical Properties of the Partial Ordered Quaternary Interlanthanide Sulfides PrLnYb2S6 (Ln = Tb, Dy)

    Energy Technology Data Exchange (ETDEWEB)

    Booth, Corwin H; Jin, Geng Bang; Choi, Eun Sang; Guertin, Robert P.; Brooks, James S.; Bray, Travis H.; Booth, Corwin H.; Albrecht-Schmitt, Thomas E.

    2008-01-11

    Dark red single crystals of PrLnYb{sub 2}S{sub 6} (Ln = Pr/Yb, Tb, Dy) have been synthesized through the reaction of elemental rare earth metals and S using a Sb{sub 2}S{sub 3} flux at 1000 C. These isotypic compounds adopt the F-Ln{sub 2}S3 three-dimensional open channel structure type. Eight-coordinate Pr{sup 3+} ions sit in the channels, which are constructed from three different edge-shared double chains running down the b axis, which contain Yb(1)S{sub 6} octahedra, Yb(2)S{sub 6}, octahedra and LnS{sub 7} monocapped trigonal prisms, respectively. Each double chain connects to four other neighbors by sharing vertices and edges. Considerable disordering in Ln positions was observed in single X-ray diffraction experiments only in the case of Pr/Yb. Least square refinements gave rise to the formulas of Pr{sub 1.34}Yb{sub 2.66}S{sub 6}, of PrTbYb{sub 2}S{sub 6}, and PrDyYb{sub 2}S{sub 6}, which are confirmed by the elemental analysis and magnetic susceptibility measurements. Pr1.34Yb2.66S{sub 6}, PrTbYb{sub 2}S{sub 6} and PrDyYb{sub 2}S{sub 6} are paramagnetic down to 2 K without any indications of long range magnetic ordering. The optical transitions for Pr{sub 1.34}Yb{sub 2.66}S{sub 6}, PrTbYb{sub 2}S{sub 6}, and PrDyYb{sub 2}S{sub 6} are at approximately 1.6 eV. Crystallographic data: Pr{sub 1.34}Yb{sub 2.66}S{sub 6}, monoclinic, space group P2{sub 1}/m, a = 10.960(2), b = 3.9501(8), c = 11.220(2) {angstrom}, {beta} = 108.545(3), V = 460.54(16), Z = 2; PrTbYb{sub 2}S{sub 6}, monoclinic, space group P2{sub 1}/m, a = 10.9496(10), b = 3.9429(4), c = 11.2206(10) {angstrom}, {beta} = 108.525(2), V = 459.33(7), Z = 2; PrDyYb{sub 2}S{sub 6}, monoclinic, space group P2{sub 1}/m, a = 10.9384(10), b = 3.9398(4), c = 11.2037(10) {angstrom}, {beta} = 108.612(2), V = 457.57(7), Z = 2.

  2. Analysis of structure origin and luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glass.

    Science.gov (United States)

    Chen, Fangze; Jing, Xufeng; Wei, Tao; Wang, Fengchao; Tian, Ying; Xu, Shiqing

    2014-08-14

    The near infrared luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glasses have been investigated. The various effects on structure and 1.53 μm emission were analyzed as a function of Yb(3+) concentration. The energy transfer mechanism was proposed. High measured lifetime (10.75 ms), large effective full widths at half maximum (73.71 nm) and large gain per unit length (62.8 × 10(-)(24)cm(2)s) have been achieved in prepared glass. The present glass co-doped with 6mol% YbF3 and 2 mol% ErF3 showed magnificent luminescence properties for telecommunication application.

  3. Neutron diffraction studies of R{sub 2}RhSi{sub 3} (R=Dy, Ho, Er) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Bazela, W.; Penc, B.; Stuesser, N.; Szytula, A.; Wawrzynska, E.; Zygmunt, A

    2004-07-15

    Powder neutron diffraction and magnetic measurements have been carried out on R{sub 2}RhSi{sub 3} (R=Dy, Ho and Er) compounds at low temperatures. These compounds crystallize in a derivative of the hexagonal AlB{sub 2}-type structure and are antiferromagnets with the Neel temperatures equal to: 6.3 K for R=Dy, 5.2 K for R=Ho and 5 K for R=Er. Below these temperatures the magnetic order is described by the propagation vector: k=(0,0,((1)/(2))) for R=Dy, k=(((1)/(2)),0,0) for R=Ho and k=(0,0,0) for R=Er. This magnetic order is stable in the temperature range between 1.5 K and the Neel temperature.

  4. Magnetism in RRhGe (R = Tb, Dy, Er, Tm): An experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Sachin [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Suresh, K.G., E-mail: suresh@phy.iitb.ac.in [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Nigam, A.K. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Lukoyanov, A.V. [Institute of Metal Physics, Russian Academy of Sciences, Ural Branch, Yekaterinburg 620137 (Russian Federation); Ural Federal University, Yekaterinburg 620002 (Russian Federation)

    2015-08-15

    Highlights: • RRhGe (R = Tb, Dy, Er, Tm) compounds show low temperature antiferromagnetic ordering. • All compounds show field induced metamagnetic transitions. • Some of these compounds show large magnetocaloric effect and magnetoresistance. • Change of sign in MR take place on temperature variation. - Abstract: RRhGe (R = Tb, Dy, Er, Tm) compounds have been studied by different experimental probes and theoretical ab initio calculations. These compounds show very interesting magnetic and transport properties. All the compounds are antiferromagnetic with some of them showing spin-reorientation transition at low temperatures. The magnetocaloric effect estimated from magnetization data shows high values in all these compounds. Magnetoresistance is negative near the ordering temperatures and positive at low temperatures. The electronic structure calculations accounting for electronic correlations in the 4f rare-earth shell reveal the closeness of the antiferromagnetic ground state and other types of magnetic orderings in the rare-earth sublattice. These calculations are also in agreement with the experimental results.

  5. Buffer gas loaded magneto-optical traps for Yb, Tm, Er and Ho

    Science.gov (United States)

    Hemmerling, Boerge; Drayna, Garrett K.; Chae, Eunmi; Ravi, Aakash; Doyle, John M.

    2014-06-01

    Direct loading of lanthanide atoms into magneto-optical traps (MOTs) from a very slow cryogenic buffer gas beam source is achieved, without the need for laser slowing. The beam source has an average forward velocity of 60-70\\;m\\;{{s}^{-1}} and a velocity half-width of \\sim 35\\;m\\;{{s}^{-1}}, which allows for direct MOT loading of Yb, Tm, Er and Ho. Residual helium background gas originating from the beam results in a maximum trap lifetime of about 80 ms (with Yb). The addition of a single-frequency slowing laser applied to the Yb in the buffer gas beam increases the number of trapped Yb atoms to 1.3\\left( 0.7 \\right)\\times {{10}^{8}} with a loading rate of 2.0\\left( 1.0 \\right)\\times {{10}^{10}}\\;atoms\\;{{s}^{-1}}. Decay to metastable states is observed for all trapped species and decay rates are measured. Extension of this approach to the loading of molecules into a MOT is discussed.

  6. Carbon implanted waveguides in soda lime glass doped with Yb3+ and Er3+ for visible light emission

    Science.gov (United States)

    Vázquez, G. V.; Valiente, R.; Gómez-Salces, S.; Flores-Romero, E.; Rickards, J.; Trejo-Luna, R.

    2016-05-01

    Channel waveguides were fabricated by carbon implantation in soda lime glass samples doped with Er3+ and Yb3+, exhibiting good confinement and both monomode and multimode behaviour at 633 nm. Excitation at near infrared (NIR) and ultraviolet (UV) spectral ranges were used in order to obtain anti-Stokes (upconversion) and Stokes (downshift) emission in the visible range, respectively. The characteristic green and red bands of Er3+ transitions were observed, showing the potential of Yb3+ and Er3+ co-doping for the generation of visible guided emission under NIR excitation.

  7. Direct Sensitization Up-conversion Mechanism in Er3+∶Yb3+ Co-doped Fluoride Materials

    Institute of Scientific and Technical Information of China (English)

    肖思国; 阳效良; 刘政威; 佘仲明; 陈春先

    2002-01-01

    Up-conversion luminescence have been studied on Yb3+-Er3+ co-doped fluoride samples. Two infrared lasers with wavelength of 930 nm and 858 nm are carefully chosen as excitation sources. The experimental results suggest direct cooperation sensitization up-conversion rather than two-step sensitization up-conversion is responsible for the increased population of 2H11/2 (Er3+) and thus the increased green emission in the region 514~574 nm in Yb3+-Er3+ co-doped system.

  8. Study on the structure and morphology of Er/Yb/Al-doped ZnO thin film%Er/Yb/Al掺杂ZnO薄膜的结构与形貌研究

    Institute of Scientific and Technical Information of China (English)

    韩利新; 张宁玉; 霍庆松; 宋红莲

    2011-01-01

    ZnO thin films and Er/Yb/Al-doped ZnO thin films on Si substrate were fabricated by using RF magnetron sputtering method at room temperature. The XRD structure analysis shows that undoped ZnO thin film grows along the C orientation, but doped ZnO thin films deviate from the normal growth orientation and become nano-multi-crystal structure which is along (102) orientation and the crystal-lite size of ZnO thin film doped the Er/Yb /Al decreases with the increase of the content of the Er ele-ment. The morphology by AFM analysis shows that Er3 + 、Yb3 +、Al3+ that is doped in the ZnO thin films cause a change of crystal field and make the surface roughness larger.%采用射频磁控溅射技术在室温下Si衬底上制备了ZnO薄膜和Er/Yb/Al掺杂的ZnO薄膜.通过对XRD的结构分析表明:未掺杂ZnO薄膜沿c取向性生长,掺杂ZnO薄膜偏离了正常生长,变为(102)取向性生长的纳米多晶结构;Er/Yb/Al掺杂的ZnO薄膜的晶粒尺寸随着Er元素含量的增多而减小.经AFM对其形貌分析表明:Er3+、yb3+、Al3+的掺入引起了ZnO薄膜晶格场变化,使薄膜表面粗糙度变大.

  9. Luminescence properties of Yb:Er:KY3F10 nanophosphor and thermal treatment effects

    Science.gov (United States)

    Gomes, Laércio; Linhares, Horácio Marconi da Silva M. D.; Ichikawa, Rodrigo Uchida; Martinez, Luis Gallego; Baldochi, Sonia Licia

    2016-04-01

    In this work, we present the spectroscopic properties of KY3F10 nanocrystals activated with erbium and codoped with ytterbium ions. The most important processes that lead to the erbium upconversion of green and red emissions of Er3+ were identified. A time-resolved luminescence spectroscopy technique was employed to measure the luminescence decays of 4S3/2 and 4F9/2 excited levels of Er3+ and to determine the upconversion processes and the luminescence efficiencies of erbium in the visible. Analysis of the luminescence kinetics in Yb:Er:KY3F10 shows a rapid upconversion (Up1) for the green emission with a time constant of 0.31 μs after pulsed laser excitation at 972 nm for as synthesized nanocrystals, which is faster than the time constant measured for the bulk crystal (23 μs). In addition, it is observed a second upconversion process (non-resonant) (Up2) responsible for the red emission (Er3+), which competes with Up1 process. However, the luminescence efficiency of the green emission (4S3/2) is observed to be very low (1.6%) for the as synthesized nanocrystal (25 °C). Nevertheless, it increases with the nanopowder heat treatment reaching an efficiency of 99% (T = 550 °C) relative to the bulk crystal. Similar luminescence behavior was observed for the 4F9/2 level (Er3+) that emits red emission. X-ray diffraction analysis of nanopowder by Rietveld method reveled that the mean crystallite size remains unchanged (8.3-12.3 nm) after thermal treatments with T ∼ 400 °C, while the 4S3/2 luminescence efficiency strongly increases to 20%. The luminescence dynamics indicates that Er3+ ions distribution plays a determinant role in the luminescence efficiency of green and red emissions of Er3+ besides also the strong influence on the upconversions processes. The observed luminescence effect is caused by the non-uniform Er3+ (and Yb3+) ions distribution due to the nanocrystal grown, which introduces a concentration gradient that increases towards the nanoparticle

  10. The effects of energy transfer on the Er3+ 1.54 μm luminescence in nanostructured Y2O3 thin films with heterogeneously distributed Yb3+ and Er3+ codopants

    Science.gov (United States)

    Hoang, J.; Schwartz, Robert N.; Wang, Kang L.; Chang, J. P.

    2012-09-01

    We report the effects of heterogeneous Yb3+ and Er3+ codoping in Y2O3 thin films on the 1535 nm luminescence. Yb3+:Er3+:Y2O3 thin films were deposited using sequential radical enhanced atomic layer deposition. The Yb3+ energy transfer was investigated for indirect and direct excitation of the Yb 2F7/2 state using 488 nm and 976 nm sources, respectively, and the trends were described in terms of Forster and Dexter's resonant energy transfer theory and a macroscopic rate equation formalism. The addition of 11 at. % Yb resulted in an increase in the effective Er3+ photoluminescence (PL) yield at 1535 nm by a factor of 14 and 42 under 488 nm and 976 nm excitations, respectively. As the Er2O3 local thickness was increased to greater than 1.1 Å, PL quenching occurred due to strong local Er3+ ↔ Er3+ excitation migration leading to impurity quenching centers. In contrast, an increase in the local Yb2O3 thickness generally resulted in an increase in the effective Er3+ PL yield, except when the Er2O3 and Yb2O3 layers were separated by more than 2.3 Å or were adjacent, where weak Yb3+ ↔ Er3+ coupling or strong Yb3+ ↔ Yb3+ interlayer migration occurred, respectively. Finally, it is suggested that enhanced luminescence at steady state was observed under 488 nm excitation as a result of Er3+ → Yb3+ energy back transfer coupled with strong Yb3+ ↔ Yb3+ energy migration.

  11. Preparation and Upconversion Luminescence of Nanocrystalline Gd2O3:Er3+,Yb3+

    Institute of Scientific and Technical Information of China (English)

    LI Yanhong; HONG Guangyan; ZHANG Yongming; DAI Caiyun; DAI shuping

    2008-01-01

    Nanocrystalline Gd1.77 Yb0.2Er0.03O3 samples were prepared by combustion and precipitation methods.Structures and upconversion luminescence properties of samples were studied.The results of XRD show that all samples are cubic structure,the average crystallite size could be calculated as 23 nm and 39 nm.respectively.The lattice constants were obtained.The FT-IR spectra were measured to investigate the vibrational feature of the samples.Upconversion luminescence spectra of samples under 980 nm laser excitation were investigated.The strong red emission of samples were observed,and attributed to 4F9/2→4I15/2 transitions of Er3+ ions,the emission intensity for sample synthesized by precipitation method is stronger compared to that of combustion method. The possible upconversion luminescence mechanisms in nanocrystalline Gd1.77Yb0.2Er0.03O3were discussed.

  12. Optical absorption and fluorescence properties of Er3+/Yb3+ codoped lead bismuth alumina borate glasses

    Science.gov (United States)

    Goud, K. Krishna Murthy; Reddy, M. Chandra Shekhar; Rao, B. Appa

    2014-04-01

    Lead bismuth alumina borate glasses codoped with Er3+/Yb3+ were prepared by melt quenching technique. Optical absorption, FTIR and photoluminescence spectra of these glasses have been studied. Judd-Ofelt theory has been applied to to the f ↔ f transitions for evaluating Ω2, Ω4 and Ω6 parameters. Radiative properties like branching ratio βr and the radiative life time τR have been determined on the basis of Judd-Ofelt theory. Upconversion emissions have been observed under 980nm laser excitation at room temperature. Green and red up-conversion emissions are centered at 530, 550 and 656 nm corresponding to 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+ respectively. The results obtained are discussed quantitatively based on the energy transfer between Yb3+ and Er3+.

  13. Determination of magnetic anisotropy in the LnTRENSAL complexes (Ln = Tb, Dy, Er) by torque magnetometry.

    Science.gov (United States)

    Perfetti, Mauro; Lucaccini, Eva; Sorace, Lorenzo; Costes, Jean Pierre; Sessoli, Roberta

    2015-04-06

    We report here a study about the magnetic anisotropy of the LnTRENSAL complexes (Ln = Tb, Dy, Er) performed by using cantilever torque magnetometry and electron paramagnetic resonance. For all of the compounds, we extracted a set of crystal-field parameters to obtain the energy-level splitting of the ground-state multiplet.

  14. HIGH REPETITION RATE MICROCHIP ER3+,YB3+:YAL3(BO34 DIODE-PUMPED LASER

    Directory of Open Access Journals (Sweden)

    K. N. Gorbachenya

    2012-01-01

    Full Text Available Diode-pumped passively Q-switched microchip Er,Yb:YAl3(BO34 laser for range-finding has been demonstrated. By using a Co2+:MgAl2O4 as a saturable absorber TEM00–mode Q-switched average output power of 315 mW was demonstrated at 1522 nm with pulse duration of 5 ns and pulse energy of 5,25 μJ at a repetition rate of 60 kHz.

  15. Experimental investigation of photoluminescence spectra of Yb3+ sensitized Er3+-doped glass samples in series

    Institute of Scientific and Technical Information of China (English)

    Chengren Li (李成仁); Changlie Song (宋昌烈); Shufeng Li (李淑凤); Jingsheng Gao (高景生)

    2003-01-01

    Fabrication technology of the Yb3+:Er3+ co-doped glass samples is introduced. Photoluminescence (PL)characteristics of a single sample were experimentally investigated. The PL peak intensities of two samples in series were measured and discussed. The results show that the PL peak intensities of two samples in series depend on pump manners and arrangement of the samples. The better amplification ability can be obtained by two samples in series doped with low-concentration ytterbium instead of a single sample doped with high-concentration ytterbium.

  16. Phosphate-core silica-clad Er/Yb-doped optical fiber and cladding pumped laser.

    Science.gov (United States)

    Egorova, O N; Semjonov, S L; Velmiskin, V V; Yatsenko, Yu P; Sverchkov, S E; Galagan, B I; Denker, B I; Dianov, E M

    2014-04-07

    We present a composite optical fiber with a Er/Yb co-doped phosphate-glass core in a silica glass cladding as well as cladding pumped laser. The fabrication process, optical properties, and lasing parameters are described. The slope efficiency under 980 nm cladding pumping reached 39% with respect to the absorbed pump power and 28% with respect to the coupled pump power. Due to high doping level of the phosphate core optimal length was several times shorter than that of silica core fibers.

  17. Lead fluorosilicate glass ceramics doped with Nd3+, Er3+, and Yb3+

    Science.gov (United States)

    Petrova, O. B.; Khomyakov, A. V.

    2013-06-01

    Glasses in the PbF2-PbO-SiO2 system doped with 1 mol % of rare-earth elements (Nd3+, Er3+, or Yb3+) are synthesized and studied. The glasses were heat-treated in order to obtain glass ceramics with a fluoride crystalline phase. The changes in the structure and spectral optical properties of glass ceramics with respect to initial glasses were determined by using X-ray diffraction analysis and by studying the luminescent characteristics of dopant ions.

  18. Electrical transport and magnetic ordering in 2Ti3Ge4 (=Dy, Ho and Er) compounds

    Indian Academy of Sciences (India)

    R Nirmala; V Sankaranarayanan; K Sethupathi; A V Morozkin; T Geethakumary; Y Hariharan

    2002-05-01

    New 2Ti3Ge4 ( = Dy, Ho and Er) intermetallic compounds have been synthesized and characterized by X-ray diffraction and low temperature ac magnetic susceptibility, electrical resistivity and thermoelectric power measurements were carried out. The compounds crystallize in the parent, Sm5Ge4-type orthorhombic structure (space group Pnma) and lanthanide contraction is observed as one moves along the rare-earth series. The changeover from paramagnetic to antiferromagnetic phase happens at low temperatures and the ordering temperature scales with the de Gennes factor. The electrical resistivity is metallic with a negative curvature above 100 K. Thermopower displays a weak maximum at temperatures less than 50 K signifying the possible phonon and magnon drag effects.

  19. Determination of the Er{sup 3+} to Yb{sup 3+} energy transfer efficiency in Er{sup 3+}/Yb{sup 3+}-codoped YVO{sub 4} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Di Paolo, R.E. [Departamento de Fisica de Materiales, C-IV, Universidad Autonoma de Madrid, Madrid (Spain); Centro de Investigaciones Opticas (CIOp), CC 124, La Plata (Argentina); Cantelar, E.; Cusso, F. [Departamento de Fisica de Materiales, C-IV, Universidad Autonoma de Madrid, Madrid (Spain)]. E-mail: fernando.cusso@uam.es; Wang, X.M. [Institute of Physics, Chinese Academy of Sciences, Beijing (China); Tsuboi, T. [Faculty of Engineering, Kyoto Sangyo University, Kamigamo, Kita-ku, Kyoto (Japan)

    2001-09-03

    The energy transfer efficiency from Er{sup 3+} to Yb{sup 3+} ions in yttrium orthovanadate single crystals (YVO{sub 4}) is experimentally obtained, by using a method based on the simultaneous and multiwavelength measurement of photoacoustic and luminescent signals after pulsed laser excitation. The result is reached by comparing with the predictions from Judd-Ofelt analysis and the lifetime measurements. The energy transfer between the ions, from Er{sup 3+} to Yb{sup 3+}, must be considered in order to fit the experimental results. A value of energy transfer efficiency ({psi}=0.16) is obtained. (author)

  20. Fabrication and photoelectric properties of Er3+ and Yb3+ co-doped ZnO films

    Science.gov (United States)

    Feng, Wei; Wang, Xiangfu; Meng, Lan; Yan, Xiaohong

    2016-01-01

    In this paper, the Er3+ and Yb3+ co-doped ZnO films deposited by a novel thermal decomposition method under different annealing temperature process have been reported. The effects of annealing temperature on the morphology and properties of the films are systematically studied. The resulting spectra demonstrate that the Er3+ and Yb3+ co-doped ZnO films possessed the property of up-conversion, converting IR light into visible light that can be absorbed by amorphous silicon solar cell. After all, inner photoelectric effect of the Er3+ and Yb3+ co-doped ZnO films in the amorphous as a light scattering layer are also found with an infrared 980 nm laser as excitation source.

  1. MW peak power Er/Yb-doped fiber femtosecond laser amplifier at 1.5 µm center wavelength

    Science.gov (United States)

    Han, Seongheum; Jang, Heesuk; Kim, Seungman; Kim, Young-Jin; Kim, Seung-Woo

    2017-08-01

    An erbium (Er)/ytterbium (Yb) co-doped double-clad fiber is configured to amplify single-mode pulses with a high average power of 10 W at a 1.5 µm center wavelength. The pulse duration at the exit of the Er/Yb fiber amplifier is measured to be ~440 fs after grating-based compression. The whole single-mode operation of the amplifier system permits the M 2-value of the output beam quality to be evaluated better than 1.05. By tuning the repetition rate from 100 MHz down to 600 kHz, the pulse peak power is scaled up to 19.1 MW to be the highest ever reported using an Er/Yb single-mode fiber. The proposed amplifier system is well suited for strong-power applications such as free-space LIDAR, non-thermal machining and medical surgery.

  2. Spectral Properties and Upconversion Luminescence of Er3+, Yb3+: BaWO4 Crystal

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The optical quality of Er3+, Yb3+: BaWO4 crystal was grown by Czochralski method. Absorption spectra were measured and energy levels were assigned. According to Judd-Ofelt theory, the spectral strength parameters of Er3+ ion were fitted to be Ω2=0.3926×10-20 cm2, Ω4=0.0721×10-20 cm2, Ω6=0.0028×10-20 cm2. Emission peaks centered at around 523, 544 and 670 nm were observed under 334 nm He-Cd laser excitation and emission peaks centered at 1001 and 1534 nm were detected under 976 nm laser excitation. Strong green emission was also observed when the crystal was pumped with 808 nm and 976 nm laser. The mechanisms of frequency upconversion and sensitization were analyzed.

  3. Spectroscopic properties and thermal stability of Er3+/Yb3+-codoped fluorophosphate glasses

    Institute of Scientific and Technical Information of China (English)

    Li Tao; Zhang Qin-Yuan; Zhao Chun; Feng Zhou-Ming; Shi Dong-Mei; Deng Zai-De; Jiang Zhong-Hong

    2005-01-01

    A comprehensive study on the thermal stability and spectroscopic properties of Er3+/Yb3+-codoped Al(PO3)3-based fluorophosphate glasses is reported of the 1.5μm fibre amplifiers in this paper. From optical absorption spectra, the Judd-Ofelt parameters of Er3+ in the glasses and several important optical properties, such as the radiative transition probability, the branching ratio and the spontaneous emission probability, have been calculated by using Judd-Ofelt theory. The fluorophosphate glass exhibits broadband near-infrared emission at 1.53 μm with a full width at halfmaximum over 63nm, and a large calculated stimulated-emission cross-section of 6.85 × 10-21cm2.

  4. Temporal dynamics of upconversion luminescence in $Er^{3+}$, $Yb^{3+}$ co-doped crystalline $KY(WO_4)_2$ thin films

    NARCIS (Netherlands)

    Garcia-Revilla, S.; Valiente, R.; Romanyuk, Y.E.; Pollnau, M.

    2008-01-01

    Crystalline $Er^{3+}$ and $Yb^{3+}$ singly and doubly doped $KY(WO_4)_2$ thin films were grown by low-temperature liquid-phase epitaxy. Absorption, luminescence, excitation and temporal evolution measurements were carried out for both $Er^{3+}$ and $Yb^{3+}$ transitions from 10K to room temperature.

  5. Experimental study on a nonlinear photonics process of Er(0.5)Yb(3):FOV oxyfluoride nanophase vitroceramics

    Science.gov (United States)

    Chen, Xiaobo; Song, Zengfu; Hu, Lili; Zhang, Junjie; Wen, Lei

    2007-07-01

    We study the nonlinear photonics of rare-earth-doped oxyfluoride nanophase vitroceramics (FOV), oxyfluoride glass (FOG), and ZBLAN fluoride glass. We found that an interesting fluorescence intensity inversion phenomenon between red and green fluorescence occurs from Er(0.5)Yb(3):FOV. The dynamic range ∑ of the intensity inversion between red and green fluorescence of Er(0.5)Yb(3):FOV is about 5.753×102, which is 100 to 1000 times larger than those of other materials. One of the applications of this phenomenon is double-wavelength fluorescence falsification-preventing technology, which is proved to possess the novel antifriction loss and antiscribble properties.

  6. Dualistic temperature sensing in Er3 +/Yb3 + doped CaMoO4 upconversion phosphor

    Science.gov (United States)

    Sinha, Shriya; Mahata, Manoj Kumar; Kumar, Kaushal; Tiwari, S. P.; Rai, V. K.

    2017-02-01

    Temperature sensing performance of Er3 +/Yb3 + doped CaMoO4 phosphor prepared via polyol method is reported herein. The X-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy are done to confirm the phase, structure and purity of the synthesized phosphor. The infrared to green upconversion emission is investigated using 980 nm diode laser excitation along with its dependence on input pump power and external temperature. The temperature dependent fluorescence intensity ratio of two upconversion emission bands assigned to 2H11/2 → 4I15/2 (530 nm) and 4S3/2 → 4I15/2 (552 nm) transitions has shown two distinct slopes in the studied temperature range - 300 to 760 K and therefore, dual nature of temperature sensitivity is observed in this phosphor. This phenomenon in rare earth doped materials is either scarcely reported or overlooked. The material has shown higher sensitivity in the high temperature region (535 K < T < 760 K) with a maximum of 7.21 × 10- 3 K- 1 at 535 K. The results indicate potential of CaMoO4: Er3 +/Yb3 + phosphor in high temperature thermometry.

  7. Spectral-converting behaviors of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} doped YOCl phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

    2014-01-25

    Highlights: • Luminescent materials of YOCl:Er,Yb were prepared using NH{sub 4}Cl flux. • Interesting spectral-converting behaviors were observed in the phosphors. • 980 or 1550 nm diode laser was irradiated for up-converting study. • A multi-photon process in the phosphors was calculated. -- Abstract: Luminescent materials composed of Y{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m = 0.001–0.1, n = 0.005–0.1) were prepared via a solid-state reaction using NH{sub 4}Cl flux. Photoluminescence spectra, the dependence of the luminescent intensity as a function of Er{sup 3+} content, and their CIE coordinates of the Er{sup 3+}-doped layered YOCl compounds were also investigated under near-ultraviolet (NUV) and visible lights. The spectral up-converting properties of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} in YOCl phosphors were elucidated under 980 and 1550 nm diode laser irradiations. This up-conversion emission spectra and the pump power dependence versus emission intensity observed in the Y{sub 0.9}Er{sub 0.1}OCl up-conversion phosphors gave rise to one- and two-photon processes. The up-conversion mechanism of Er{sup 3+} and Yb{sup 3+} ions in YOCl was described by a schematic energy-level diagram. Through the use of these up-conversion luminescent materials, the desired emitting lights throughout the orange and red regions of the spectra were achieved.

  8. Influence of Er3+/Yb3+ concentration ratio on the down-conversion and up-conversion luminescence and lifetime in GdVO4:Er3+/Yb3+ microcrystals

    Directory of Open Access Journals (Sweden)

    Gavrilović T.V.

    2015-01-01

    Full Text Available In this paper, we studied the effects of Er3+/Yb3+ concentration ratio on structural, morphological and luminescence properties of GdVO4:Er3+/Yb3+ green phosphors prepared by a high-temperature solid state method. The samples with different concentrations (between 0.5 to 2 mol% of dopant Er3+ emitting ions and different concentrations (between 5 to 20 mol% of sensitizer ions (Yb3+ were studied. The phosphors were characterized by the X-ray diffraction (XRD, scanning electron microscopy (SEM and photoluminescence spectroscopy. For all samples, XRD diffraction patterns confirmed a formation of a pure GdVO4 phase, while the SEM showed that the materials are comprised of chunks of deformed particles with an average diameter ranging from approximately 2 μm to 8 μm. Both, down-conversion and up-conversion emission spectra of GdVO4:Er3+/Yb3+ samples, under near UV and IR excitations, exhibit two strong emission bands in the green spectral region at 525 nm and 552 nm wavelengths corresponding to 2H11/2 →4I15/2 and 4S3/2 → 4I15/2 electronic transitions of Er3+ ions. The intensity of the green emission was changed by changing the Er3+/Yb3+ concentration ratio. This dual-mode luminescence makes these materials ideal as green phosphors for a wide variety of applications in the fields of bioanalysis and biomedical. [Projekat Ministarstva nauke Republike Srbije, br. 45020 i br. 172056

  9. Molten solvent extraction behavior of trivalent La, Sm, Dy, and Yb withtri-n-butyl phosphate into molten paraffin wax at 60 ℃

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The extraction behavior of La3+, Sm3+, Dy3+, and Yb3+ in sodium acetate-acetic acid medium was studied with tri-n-butyl phosphate (TBP) at 60 ℃ using paraffin wax as a diluent. The extraction percentage is greater than 85% in the pH range of 6 to 8. The result of slope analysis method indicates that the compositions of the extracted species are different between the light and heavy rare earths. The formula of the extracted species is found to be La(TBP)(OH)(Ac)2for La3+ and Yb(TBP)(OH)3 for Yb3+. The effects of extracting time, the concentration of TBP in the organic phase and salts on the extraction efficiency were also discussed.

  10. Low temperature sensing behavior of upconversion luminescence in Er3+/Yb3+ codoped PLZT transparent ceramic

    Science.gov (United States)

    Feng, Zhuohong; Lin, Lin; Wang, ZheZhe; Zheng, Zhiqiang

    2017-09-01

    In this paper, low temperature sensing characteristic of upconversion luminescence in Er3+/Yb3+ codoped lead-lanthanum zirconate-titanate ferroelectric ceramics (PLZT) was investigated by fluorescence intensity ratios (FIRs). The upconversion emissions at 539 nm, 564 nm and 666 nm were observed from 10 K to 320 K by exciting at 980 nm. These emissions were assigned to the transitions 2H11/2→4I15/2, 4S3/2→4I15/2, and 4F9/2→4I15/2, respectively. The temperature dependent emission intensities of upconversion luminescence were analyzed, from which the thermal excitation processes among the three levels system of 2H11/2, 4S3/2 and 4F9/2 were discovered. Based on this, the FIRs of 539 nm to 666 nm, 539 nm to 564 nm are studied, and the variation trends of them agree with the Boltzmann distribution of thermal coupled in the temperature range of 140-320 K. The temperature sensitivity of intensity ratio of 539 nm to 666 nm is 21.84×10-4 K-1 at 320 K, which is about 4 times than that of 539 nm to 564 nm. The temperature sensing performance can be improved by high valued ΔE of thermal coupled levels (TCLs). This paper shows that 2H11/2 and 4F9/2 of Er3+ are TCLs in PLZT, and the upconversion luminescence of Er3+/Yb3+ codoped PLZT transparent ceramic have a potential application in low temperature sensing above 140 K.

  11. Green Upconversion Luminescence in Er3+/Yb3+ Codoped CaWO4 Polycrystals

    Institute of Scientific and Technical Information of China (English)

    XU Yan-Ling; ZHAO Hong; WANG Rui; ZHANG Chun-Yu

    2011-01-01

    CaWO4 polycrystals with fixed Yb3+ and various Ei2* concentrations are synthesized via the high temperature solid state method. The crystal structure of the polycrystals is characterized by means of x-ray diffraction. The upconversion properties of the polycrystals under the 980 nm excitation are investigated. Intense emission bands centered at 530nm and 552nm correspond to the transitions 2H11/2 → 4hs/2 and 4S3/2→ 4hs/2 of Er3+, respectively. The dependence of intensity of the green emission on the pump power and possible upconversion mechanism are discussed. Quantitative analysis of dependence of upconversion emission intensity on the pump power of a laser diode indicates that two-photon processes are responsible for both 530 nm and 552 nm green upconversion emissions.%@@ CAWO polycrystals with fixed Yb and various Er concentrations are synthesized via the high temperature solid state method.The crystal structure of the polycrystals is characterized by means of x-ray diffraction.The upconversion properties of the polycrystals under the 980 nm excitation are investigated.Intense emission bands centered at 530hm and 552nm correspond to the transitions H → I and S → I of Er, respectively.The dependence of intensity of the green emission on the pump power and possible upconversion mechanism are discussed.Quantitative analysis of dependence of upconversion emission intensity on the pump power of a laser diode indicates that two-photon processes are responsible for both 530hm and 552nm green upconversion emissions.

  12. Effect of concentration quenching on the spectroscopic properties of Er3+/Yb3+ co-doped AlF3-based glasses

    Institute of Scientific and Technical Information of China (English)

    Junjie Zhang(张军杰); Shixun Dai(戴世勋); Shiqing Xu(徐时清); Guonian Wang(汪国年); Liyan Zhang(张丽艳); Lili Hu(胡丽丽)

    2004-01-01

    A series of highly Er3+/Yb3+ co-doped fluoroaluminate glasses have been investigated in order to develop a microchip laser at 1.54 μm under 980 nm excitation. Measurements of absorption, emission and upconversion spectra have been performed to examine the effect of Er3+/Yb3+ concentration quenching on spectroscopic properties. In the glasses with Er3+ concentrations below 10 mol%, concentration quenching is very low and the Er3+/Yb3+ co-doped fluoroaluminate glasses have stronger fluorescence of 1.54 μm due to the 4I13/2 → 4I15/2 transition than that of Er3+ singly-doped glasses. As Er3+ concentrations above 10 mol% in the Er3+/Yb3+ co-doped samples, concentration quenching of 1.54 μm does obviously occur as a result of the back energy transfer from Er3+ to Yb3+. To obtain the highest emission efficiency at 1.54 μm, the optimum doping-concentration ratio of Er3+/Yb3+ was found to be approximately 1:1 in mol fraction when the Er3+ concentration is less than 10 mol%.

  13. Upconversion and tribological properties of β-NaYF{sub 4}:Yb,Er film synthesized on silicon substrate

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chuanying [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Cheng, Xianhua, E-mail: xhcheng@sjtu.edu.cn [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-05-15

    Highlights: • β-NaYF{sub 4}:Yb,Er upconversion (UC) film was synthesized on silicon substrate. • Tribological test was used to qualitatively evaluate the adhesion of the UC film. • The UC film was combined with Si substrate by covalent chemical bonds. • The method used in this work can be applicable for other UC films. - Abstract: In this work, β-NaYF{sub 4}:Yb,Er upconversion (UC) film was successfully prepared on silicon (Si) substrate via self-assemble method for the first time. The chemical composition and surface morphology of the UC film were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), water contact angle (WCA), X-ray power diffraction (XRD), and scanning electron microscopy (SEM) measurements. To investigate the effects of KH-560 primer film and chemical reactions on the UC luminescence properties of β-NaYF{sub 4}:Yb,Er UC film, decay profiles of the 540 nm and 655 nm radiations were measured. Furthermore, tribological test was applied to qualitatively evaluate the adhesion of the UC film. The results indicate that the UC film has been successfully prepared on Si substrate by covalent chemical bonds. This work provides a facile way to synthesize β-NaYF{sub 4}:Yb,Er UC film with robust adhesion to the substrate, which can be applicable for other UC films.

  14. Utilization of IR laser pumped anti-Stokes emission of Er-Yb doped systems for identification of securities

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmin, A.N.; Ryabtsev, G.I.; Ketko, G.A. [Institute of Physics, Belarussian Academy of Sciences, Minsk (Belarus); Gorelenko, A.Yu.; Demidovich, A.A. [Science Center `Gosznak` of Belarus, Minsk (Belarus); Strek, W.; Maruszewicz, K.; Deren, P. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wroclaw (Poland)

    1996-12-31

    In this paper we present a utilization of anti-Stokes luminescence of Er-Yb systems for identification of securities. A simple method of detection of an up-conversion phenomenon in such system by means of IR laser operating in the region 960-1010 nm is proposed. (author) 3 refs, 3 figs

  15. Linearly polarized, single-frequency, widely tunable Er:Yb bulk laser at around 1550 nm wavelength

    Energy Technology Data Exchange (ETDEWEB)

    Taccheo, S.; Laporta, P.; Svelto, O. [Centro di Elettronica Quantistica e Strumentazione Elettronica del CNR, Dipartimento di Fisica del Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano (Italy)

    1996-11-01

    We report on a 36 nm tunable, single-frequency, linearly polarized Er:Yb:glass laser. A tuning range from 1528 to 1564 nm, with output power ranging from 1 to 8 mW, is achieved. Wavelength tuning and linearly polarized output are simultaneously obtained by using a special polarizing etalon with anisotropic absorption losses. {copyright} {ital 1996 American Institute of Physics.}

  16. Sensitized near-infrared luminescence from polydentate triphenylene-functionalized Nd3+, Yb3+, and Er3+ complexes

    NARCIS (Netherlands)

    Klink, S.I.; Hebbink, G.A.; Grave, L.; Veggel, van F.C.J.M.; Reinhoudt, D.N.; Slooff, L.H.; Polman, A.; Hofstraat, J.W.

    1999-01-01

    Hexa-deutero dimethylsulfoxide (DMSO-d6) solutions of terphenyl-based Nd3+ , Yb3+, and Er3+ complexes functionalized with a triphenylene antenna chromophore exhibit room temperature near-infrared luminescence at wavelengths of interest for the optical telecommunication network (~ 1330 and ~ 1550 nm)

  17. Luminescence resonance energy transfer based on β-NaYF_4:Yb,Er nanoparticles and TRITC dye

    Institute of Scientific and Technical Information of China (English)

    SUN LingDong; GU JianQin; ZHANG ShuZhuo; ZHANG YaWen; YAN ChunHua

    2009-01-01

    β-NaYF_4:Yb,Er nanoparticles (NPs) are one of the most efficient upconversion materials, which can convert near-infrared light to higher-energy light through multiple photon absorptions or energy transfer. In addition, they may be attractive alternative donors for luminescence resonance energy transfer (LRET) studies, because of their sharp absorption and emission profiles, high quantum yields, large anti-stokes shifts, long lifetime, low toxicity, and superior photo-stability. In principle, many problems of fluorescence resonance energy transfer (FRET), such as excitation of acceptors, emission overlaps between donors and acceptors, high background noise, potential toxicity, and instability, can be overcome using β-NaYF_4:Yb,Er NPs as energy donors. Because the organic coating induced separation can significantly reduce the energy transfer efficiency and aqueous FRET system is difficult to be applied in devices, we demonstrate a novel NP-dye LRET system in solid state. The emission of the β-NaYF_4:Yb,Er NPs at 539 nm overlaps with the absorption of the tetrametrylrhodarnine isothiocyante (TRITC), satisfying the requirement of LRET process. Since TRITC molecules are adsorbed on the β-NaYF_4:Yb,Er NPs by an electrostatic interaction, the interaction distance is suitable for LRET without any further modulation. The resultant solid LRET system is ready for the further applications for devices.

  18. Monolithic thermally bonded Er3+, Yb3+:glass/Co2+:MgAl2O4 microchip lasers

    Science.gov (United States)

    Mlynczak, Jaroslaw; Belghachem, Nabil

    2015-12-01

    The highest ever reported 10 kW peak power in monolithic thermally bonded Er3+, Yb3+:glass/Co2+:MgAl2O4 microchip laser was achieved. To show the superiority of monolithic microchip lasers over those with external mirrors the laser generation characteristics of the same samples in both cases were compared.

  19. Effect of Yb3+ concentration on Er3+ luminescence properties of sol-gelderived silica-alumina xerogels

    Institute of Scientific and Technical Information of China (English)

    K.Tran Ngoc; S.Pelli; G.C.Righini; H.Pham Thanh; C.Nguyen Duc; C.Armellini; A.Chiasera; M.Ferrari; Y.Jestin; M.Montagna; E.Moser

    2006-01-01

    @@ Er3+/Yb3+ co-doped silica-alumina monolithic xerogels were prepared with the same concentration on 2 000 Er/Si ppm and 6 000 Al/Si ppm.The Yb/Si content was varied from 0 to 4 000 ppm.Densification of the samples was achieved by thermal treatment in air at 950 ℃ for 120 hours with a heating rate 0.1 ℃/min.Photoluminescence spectroscopy was used to obtain information about the effective excitation efficiency of Er3+ ions by co-doping with Yb3+ ions.The infrared-to-visible up-conversion luminescence has been investigated upon continuous wave excitation at 980 nm.The samples exhibit red,green and blue up-conversion emission.It is found that the intensity of up-conversion luminescence increases with increasing Yb3+ doping concentration.An opposite behavior is observed for the 4I13/2 luminescence of the Er3+ ions.

  20. Luminescence resonance energy transfer based on β-NaYF4:Yb,Er nanoparticles and TRITC dye

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    β-NaYF4:Yb,Er nanoparticles (NPs) are one of the most efficient upconversion materials, which can convert near-infrared light to higher-energy light through multiple photon absorptions or energy transfer. In addition, they may be attractive alternative donors for luminescence resonance energy transfer (LRET) studies, because of their sharp absorption and emission profiles, high quantum yields, large anti-stokes shifts, long lifetime, low toxicity, and superior photo-stability. In principle, many problems of fluorescence resonance energy transfer (FRET), such as excitation of acceptors, emission overlaps between donors and acceptors, high background noise, potential toxicity, and instability, can be overcome using β-NaYF4:Yb,Er NPs as energy donors. Because the organic coating induced separation can significantly reduce the energy transfer efficiency and aqueous FRET system is difficult to be applied in devices, we demonstrate a novel NP-dye LRET system in solid state. The emission of the β-NaYF4:Yb,Er NPs at 539 nm overlaps with the absorption of the tetrametrylrhodarnine isothiocyante (TRITC), satisfying the requirement of LRET process. Since TRITC molecules are adsorbed on the β-NaYF4:Yb,Er NPs by an electrostatic interaction, the interaction distance is suitable for LRET without any further modulation. The resultant solid LRET system is ready for the further applications for devices.

  1. Synthesis of Er3+ and Er3+ : Yb3+ doped sol–gel derived silica glass and studies on their optical properties

    Indian Academy of Sciences (India)

    Dipankar Mandal; H D Banerjee; M L N Goswami; H N Acharya

    2004-08-01

    Er3+ and Er3+ : Yb3+ doped optical quality, crack and bubble free glasses for possible use in making laser material have been prepared successfully through sol–gel route. The thermal and optical, including UV-visible absorption, FTIR etc characterizations were undertaken on the samples. The absorption characteristics of Er3+ doped samples clearly revealed the absorption due to Er3+ ions. On the other hand Yb3+ : Er3+ doped samples showed enhanced absorption due to ${}^{2}F_{7/2} \\rightarrow {}^{2}F_{5/2}$ transition. The absorption and emission crosssection for ${}^{2}F_{7/2} \\leftrightarrow {}^{2}F_{5/2}$ of Yb3+ were estimated. FTIR absorption spectra have clearly shown the reduction of the absorption peak intensity with heat treatment in the range 3700–2900 cm-1. The 960 cm-1 band also showed progressive decrease in the absorption band peak intensity with heat treatment. The result of the investigations with essential discussions and conclusions have been reported in this paper.

  2. Study of the magnetocaloric properties of the antiferromagnetic compounds RGa2 (R = Ce, Pr, Nd, Dy, Ho and Er).

    Science.gov (United States)

    dos Reis, R D; da Silva, L M; dos Santos, A O; Medina, A M N; Cardoso, L P; Gandra, F G

    2010-12-08

    Magnetocaloric properties of antiferromagnetic RGa(2) (R = Ce, Pr, Nd, Dy, Ho and Er) compounds have been reported. These systems present an antiferromagnetic transition below 15 K and a field induced metamagnetic transition from the antiferromagnetic to ferromagnetic state. Our results show that the character of the magnetic field induced transition along the series affects the magnetocaloric properties. For the compounds with R = Ho, Dy and Er both negative and positive magnetocaloric effect (MCE) were observed above μ(0)ΔH = 2 T where the rate between negative and positive MCE contributions depends on how the magnetic transitions occur in these compounds. The evaluated values of maximum magnetocaloric properties of RGa(2) compounds are similar to other potential magnetic refrigerant materials reported in the literature.

  3. Ion-redistribution induced efficient upconversion in β-NaYFsub>4sub>:20%Yb3+,2%Er3+ microcrystals with well controlled morphology and size.

    Science.gov (United States)

    Fan, Shaohua; Wang, Shikai; Yu, Lu; Sun, Hongtao; Gao, Guojun; Hu, Lili

    2017-01-09

    We develop an efficient green upconversion (UC) β-NaYFsub>4sub>:20%Yb3+,2%Er3+ microcrystal with well controlled morphology and size by hydrothermal method using two different chelating agents of CIT and EDTA-2Na via a simple ion-exchange reaction. Importantly, the UC emission efficiency of newly developed CIT and EDTA-2Na β-NaYFsub>4sub>:20%Yb3+,2%Er3+ microcrystals is almost as strong as that of commercial counterpart by solid-state method. A proof-of-concept β-NaYFsub>4sub>:20%Yb3+,2%Er3+ microcrystal waveguide is demonstrated to extend their applications in modern micro-optoelectronics. The local ion-redistribution process during the ion-exchange reaction, which effectively disperses the locally clustered Yb3+, accounts for the enormously enhanced UC emission in β-NaYFsub>4sub>:20%Yb3+,2%Er3+ microcrystals.

  4. Evaluation of spectroscopic properties of Er3+/Yb3+/Pr3+: SrGdGa3O7 crystal for use in mid-infrared lasers

    Science.gov (United States)

    Xia, Houping; Feng, Jianghe; Wang, Yan; Li, Jianfu; Jia, Zhitai; Tu, Chaoyang

    2015-01-01

    Er3+/Yb3+/Pr3+: SrGdGa3O7 crystal was firstly grown by Czochralski method. Detailed spectroscopic analyses of Er3+/Yb3+/Pr3+: SrGdGa3O7 were carried out. Besides better absorption characteristic, the spectra of Er3+/Yb3+/Pr3+: SrGdGa3O7 show weaker up-conversion and near-infrared emissions as well as superior mid-infrared emission in comparison to Er3+: SrGdGa3O7 and Er3+/Yb3+: SrGdGa3O7 crystals. Furthermore, the self-termination effect for Er3+ 2.7 μm laser is suppressed successfully because the fluorescence lifetime of the 4I13/2 lower level of Er3+ decreases markedly while that of the upper 4I11/2 level changes slightly in Er3+/Yb3+/Pr3+: SrGdGa3O7 crystal. The sensitization effect of Yb3+ and deactivation effect of Pr3+ ions as well as the energy transfer mechanism in Er3+/Yb3+/Pr3+: SrGdGa3O7 crystal were also studied in this work. The introduction of Yb3+ and Pr3+ is favorable for achieving an enhanced 2.7 μm emission in Er3+/Yb3+/Pr3+: SrGdGa3O7 crystal which can act as a promising candidate for mid-infrared lasers. PMID:26369289

  5. Evaluation of spectroscopic properties of Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal for use in mid-infrared lasers.

    Science.gov (United States)

    Xia, Houping; Feng, Jianghe; Wang, Yan; Li, Jianfu; Jia, Zhitai; Tu, Chaoyang

    2015-09-15

    Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal was firstly grown by Czochralski method. Detailed spectroscopic analyses of Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 were carried out. Besides better absorption characteristic, the spectra of Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 show weaker up-conversion and near-infrared emissions as well as superior mid-infrared emission in comparison to Er(3+): SrGdGa3O7 and Er(3+)/Yb(3+): SrGdGa3O7 crystals. Furthermore, the self-termination effect for Er(3+) 2.7 μm laser is suppressed successfully because the fluorescence lifetime of the (4)I(13/2) lower level of Er(3+) decreases markedly while that of the upper (4)I(11/2) level changes slightly in Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal. The sensitization effect of Yb(3+) and deactivation effect of Pr(3+) ions as well as the energy transfer mechanism in Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal were also studied in this work. The introduction of Yb(3+) and Pr(3+) is favorable for achieving an enhanced 2.7 μm emission in Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal which can act as a promising candidate for mid-infrared lasers.

  6. Subsolidus Phase Relations of the CaO-REOx-CuO Systems (RE = Eu, Tb, Dy, Ho, Er, Lu and Sc) at 900 °C in Air

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude

    2016-01-01

    The subsolidus phase relations of the CaO-REOx-CuO systems (RE = Eu, Tb, Dy, Ho, Er, Lu and Sc) were investigated in air at 900 °C. The pseudo-ternary sections with RE = Tb, Dy, Ho, Er and Lu have a similar structure. They have in common with the RE = Eu system a solid solution of Ca0.833−xRExCuO2...... in the other systems at 900 °C in air....

  7. Magnetic phase diagrams of R2RhIn8 (R = Tb, Dy, Ho, Er and Tm) compounds.

    Science.gov (United States)

    Cermák, P; Kratochvílová, M; Pajskr, K; Javorský, P

    2012-05-23

    We have grown and characterized single crystals of R(2)RhIn(8) (R=Tb, Dy, Ho, Er and Tm) compounds crystallizing in the tetragonal Ho(2)CoGa(8)-type crystal structure. Their magnetic properties were studied by specific heat and magnetization measurements. All the investigated compounds order antiferromagnetically with Néel temperatures of 43.6, 25.1, 10.9, 3.8 and 4.1 K, respectively. Magnetic phase diagrams were constructed.

  8. Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

    Energy Technology Data Exchange (ETDEWEB)

    Lluscà, M., E-mail: marta.llusca@ub.edu [Department of Applied Physics and Optics, Universitat de Barcelona, Barcelona 08028 (Spain); López-Vidrier, J. [Department of Electronics, Universitat de Barcelona, Barcelona 08028 (Spain); Lauzurica, S.; Sánchez-Aniorte, M.I. [Centro Laser, Universidad Politécnica de Madrid, Madrid 28031 (Spain); Antony, A. [Department of Applied Physics and Optics, Universitat de Barcelona, Barcelona 08028 (Spain); Indian Institute of Technology Bombay, Mumbai 400076 (India); Molpeceres, C. [Centro Laser, Universidad Politécnica de Madrid, Madrid 28031 (Spain); Hernández, S.; Garrido, B. [Department of Electronics, Universitat de Barcelona, Barcelona 08028 (Spain); Bertomeu, J. [Department of Applied Physics and Optics, Universitat de Barcelona, Barcelona 08028 (Spain)

    2015-11-15

    Transparent and conducting ZnO:Er:Yb thin films with visible up-conversion (660-nm emission under 980-nm excitation) were fabricated by RF magnetron sputtering. The as-deposited films were found to be transparent and conducting and the activation of the Er ions in these films to produce up-conversion luminescence was achieved by different post-deposition annealing treatments in air, vacuum or by laser annealing using a Nd:YVO{sub 4} laser. The structural, electrical and optical properties and the up-conversion efficiency of these films were found to be strongly influenced by the annealing method, and a detailed study is reported in this paper. It has been demonstrated that, although the air annealing was the most efficient in terms of up-conversion, laser annealing was the only method capable of activating Er ions while preserving the electrical conductivity of the doped films. It has been shown that a minimum energy was needed in laser annealing to optically activate the rare earth ions in the ZnO host material to produce up-conversion. Up-converting and transparent conducting ZnO:Er:Yb films with an electrical resistivity of 5×10{sup −2} Ω cm and transparency ~80% in the visible wavelength range has been achieved by laser annealing. - Highlights: • Transparent and conducting ZnO:Er:Yb films were grown via magnetron sputtering. • Post-annealing ZnO:Er:Yb is needed to optically activate Er ions. • Visible up-conversion emission at 660 nm is observed under 980 nm excitation. • A transparent and conducting up-converter is achieved by laser annealing.

  9. Size and shape effects in β-NaGdF4: Yb3+, Er3+ nanocrystals

    Science.gov (United States)

    Noculak, Agnieszka; Podhorodecki, Artur

    2017-04-01

    Three sets of β-NaGdF4:Yb3+, Er3+ nanocrystals (NCs) with different shapes (spherical and more complex flower shapes), different sizes (6-17 nm) and Yb3+ concentrations (2%-15%) were synthesized by a co-precipitation method using oleic acid as a stabilizing agent. The uncommon, single-crystalline flower-shaped NCs were obtained by simply adjusting the fluorine-to-lanthanides molar ratio. Additionally, some of the NCs with different sizes have been covered by the un-doped shell. The crystal phase, shapes and sizes of all NCs were examined using transmission electron microscopy and x-ray diffraction methods. Simultaneously, upconversion luminescence and lifetimes, under 980 nm excitation, were measured and the changes in green to red (G/R) emission ratios as well as emission decay times were correlated with the evolution of nanocrystal sizes and surface to volume ratios. Three different mechanisms responsible for the changes in G/R ratios were presented and discussed.

  10. Synthesis of NaYF4:Yb3+, Er3+ upconversion nanoparticles in normal microemulsions

    Directory of Open Access Journals (Sweden)

    Shan Shu-Nan

    2011-01-01

    Full Text Available Abstract An interface-controlled reaction in normal microemulsions (water/ethanol/sodium oleate/oleic acid/n-hexane was designed to prepare NaYF4:Yb3+, Er3+ upconversion nanoparticles. The phase diagram of the system was first studied to obtain the appropriate oil-in-water microemulsions. Transmission electron microscopy and X-ray powder diffractometer measurements revealed that the as-prepared nanoparticles were spherical, monodisperse with a uniform size of 20 nm, and of cubic phase with good crystallinity. Furthermore, these nanoparticles have good dispersibility in nonpolar organic solvents and exhibit visible upconversion luminescence of orange color under continuous excitation at 980 nm. Then, a thermal treatment for the products was found to enhance the luminescence intensity. In addition, because of its inherent merit in high yielding and being economical, this synthetic method could be utilized for preparation of the UCNPs on a large scale.

  11. Influence of Input Pulse Durations on Properties of Er3+/Yb3+ Co-doped DCFA

    Institute of Scientific and Technical Information of China (English)

    ZHAN Sheng-bao; ZHAO Shang-hong; SHI Lei; XU Jie; ZHAO Xiao-ming

    2006-01-01

    Based on propagation-rate equations,the influence of different input pulse durations on the properties of Er3+/Yb3+ co-doped double-clad fiber amplifier at dynamic equilibrium was analyzed. The change characteristic of output power sag with pulse duration and repetition rate was shown. Whether single or multi-channel input pulses are amplified,the shorter the input pulse duration is,the smaller the power sags of output pulse will be. At low repetition rate,upper gain values(Gupper) of gain swing are almost the same for different input pulse durations,which tend to the small signal gain,but lower gain value(Glower) of short input pulse is larger than that of long input pulse. At high repetition rate,lower gain value(Glower) approaches to upper gain value(Gupper).

  12. Geometry modulated upconversion photoluminescence of individual NaYF4: Yb3+, Er3+ microcrystals

    Science.gov (United States)

    Wang, Bing; Wang, Jiao; Mei, Yongfeng

    2017-02-01

    Upconversion (UC) photoluminescence (PL) properties of individual β-NaYF4: Yb3+, Er3+ microcrystals are investigated on their crystal orientation and size by a confocal micro-photoluminescence (μ-PL) system. The UC PL intensities including red and green bands of individual microcrystals change nearly lineally with their diameter but in different slopes. The ratio of integrated PL intensities between red and green bands (R/G) of individual microcrystals can be modulated by the crystal geometry, which is attributed to the optical propagation path and optical loss coefficient α. PL emission mapping along the crystal surface reveals a typical characteristic of optical waveguide in our UC microcrystals. Importantly, the variation of anisotropy in (100) and (001) crystal plane influences the UC PL spectra in the single microcrystals. Our finding could help the basic understanding of UC luminescence in micro/nanocrystals and hint their optimized fabrication for enhanced light emission.

  13. High performance ErYb:Glass for eye-safe lasers

    Science.gov (United States)

    George, Simi

    2016-03-01

    Phosphate glasses are known to produce high gain for the Er3+ emission into 1540nm, especially when sensitized with Yb. Unfortunately, the phosphate glass matrix tends to be weaker than other available amorphous materials. Unlike crystalline materials, glass chemical structure around the active ion can be optimized for both material strength and laser output. Reported here is the result from a design of experiment that was completed in order to strengthen the glass structure of a commercially available phosphate laser glass without impacting its laser output efficiencies. Laser output performance results for the glass that met the targeted thermal and mechanical limits are presented. This effort concludes with a scalable material that is ultimately released to the commercial market.

  14. Enhanced upconversion luminescence of NaYF4:Yb, Er microprisms via La3+ doping

    Science.gov (United States)

    Fu, Junxiang; Zhang, Xiaozeng; Chao, Zhicong; Li, Zibo; Liao, Jinsheng; Hou, Dejian; Wen, Herui; Lu, Xiaoneng; Xie, Xinrong

    2017-02-01

    A series of β-NaYF4: Yb, Er micro-prisms codoped with La3+(0-30 at%) were synthesized via hydrothermal process. Upon 980 nm excitation at room temperature, 20 mol% La3+ codoped sample shows a maximum upconversion emission intensity. Excitation power density dependencies of UC luminescence and the decay curves were investigated. The UCPL decay is evidently monoexponential for all samples and La3+ doping did not significantly change the decay time. In this particular case, we found the napierian logarithm of the UC emission intensity (lnI) had a good linear relationship with the cell lattice parameters. This correlation may be helpful for design and fabrication of high performance upconversion materials.

  15. Bioconjugation of poly(acrylic acid)-capped BaYF5:Yb3+/Er3+ up-conversion nanoparticles to bovine serum albumin: synthesis and photoluminescent properties.

    Science.gov (United States)

    Shao, Wanyue; Sun, Zhengang; Hua, Ruinian; Zhang, Wei; Zhao, Jun; Na, Liyan

    2014-05-01

    Water-soluble BaYF5:Yb3+/Er3+ nanoparticles with the surface functionalized by a layer of poly(acrylic acid) (PAA) were synthesized via a facile one-step PAA-assisted hydrothermal method. Bovine serum albumin (BSA) protein was conjugated with BaYF5:Yb3+/Er3+ upconversion nanoparticles via free carboxylic acid groups on the surface of nanoparticles. The final products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), infrared (IR) spectrophotometry, ultraviolet (UV) spectrophotometry and photoluminescence spectroscopy (PL). The XRD results showed that PAA-capped BaYF5:Yb3+/Er3+ upconversion nanoparticles could be obtained via a PAA assisted hydrothermal process with the pH value of 8 at 200 degrees C for 24 h. The TEM results showed that the morphology of BaYF5:Yb3+/Er3+ nanoparticles was spherical particles with an average diameter of about 4 nm. The IR and UV spectra showed that BSA has been conjugated with BaYF5:Yb3+/Er3+ up-conversion nanoparticles. The luminescence properties of BaYF5:Yb3+/Er3+ up-conversion nanoparticles were also studied. The luminescence properties of the products suggest that BaYF5:Yb3+/Er3+ upconversion nanoparticles have promising applications for labels in biological assays.

  16. Rare Earth Dopant (Nd, Gd, Dy, and Er Hybridization in Lithium Tetraborate

    Directory of Open Access Journals (Sweden)

    Tony D. Kelly

    2014-05-01

    Full Text Available The four dopants (Nd, Gd, Dy, and Er substitutionally occupy the Li+ sites in lithium tetraborate (Li2B4O7: RE glasses as determined by analysis of the extended X-ray absorption fine structure. The dopants are coordinated by 6-8 oxygen at a distance of 2.3 to 2.5 Å, depending on the rare earth. The inverse relationship between the RE¬ O coordination distance and rare earth (RE atomic number is consistent with the expected lanthanide atomic radial contraction with increased atomic number. Through analysis of the X-ray absorption near edge structure, the rare earth dopants adopt the RE3+ valence state. There are indications of strong rare earth 5d hybridization with the trigonal and tetrahedral formations of BO3 and BO4 based on the determination of the rare earth substitutional Li+ site occupancy from the X-ray absorption near edge structure data. The local oxygen disorder around the RE3+ luminescence centers evident in the structural determination of the various glasses, and the hybridization of the RE3+ dopants with the host may contribute to the asymmetry evident in the luminescence emission spectral lines. The luminescence emission spectra are indeed characteristic of the expected f-to-f transitions; however, there is an observed asymmetry in some emission lines.

  17. 信息动态%Spectral Analysis of Ho3+ -doped and Ho3+, Yb3+, Er3+ Co-doped Up-conversion Luminescence Borosilicate Glass

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A series of holmium ions doped borosilicate glass, including Ho3+ -doped, Ho3+/ Er3+ -doped, Ho3+/ Y Yb3+-doped and Ho3 Yb3 YEr3+ -doped galss, have been prepared by high-temperature melting. The up-conversion excitation spectra and emission spectra of the samples decrease. The analysis result reveals that both the intensities of excitation spectra and emission spectra were weaken with the Ho3+ concentration. The spectral intensities of Ho3+/Yb3+ -doped borosilicate glass increase with the increase of Ho3+ concentration because of the sensitization of Yb3+. The excitation and emission spectra intensities of Ho3+/Yb3 +/Er3+-doped borosilicate glass are weak, and the reason is the energy transfers from Ho3+ ions to Er3+ ions through energy resonant transfer process. Meanwhile the luminescence mechanism of broadband emission peaked at 550 nm is analyzed.

  18. Er3+ and Yb3+ Codoped Phosphate Laser Glass for High Power Flashlamp Pumping

    Institute of Scientific and Technical Information of China (English)

    FANG Yong-Zheng; JIN Ming-Lin; WEN Lei; LI Shun-Guang; HU Li-Li

    2007-01-01

    A novel Yb3+-Er3+ codoped phosphate glass for high power flashlamp pumping and high repetition rate laser at 1.54 μm, designated EAT5-2, is developed. The weight-loss rate of is 1.3×10-5 gcm-2h-l in boiling water, which is comparable to Kigre's QX-Er glass. Some spectroscopic parameters are analysed by Judd-Ofelt theory and McCumber theory. The emission cross section is calculated to be 0.73×10-20 cm2. The thermo-mechanical properties of EAT5-2 are modified after an ion-exchange chemical strengthening process in a KNO3/NaNO3 molten salt bath. The thresholds for optical damage from the nashlamp pumping are tested on glass rods. A repetition rate of 15 Hz is achieved for chemically strengthened glass. The laser experimental results at 1.54 μm from nashlamp pumping are also reported.

  19. Spectroscopic investigation of zinc tellurite glasses doped with Yb3 + and Er3 + ions

    Science.gov (United States)

    Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

    2016-08-01

    This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80 - x - y) TeO2 + (0.20) ZnO + xEr2O3 + yYb2O3 (x = 0, y = 0; x = 0.004, y = 0; x = 0, y = 0.05 and x = 0.004, y = 0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er3 + glasses as erbium doped fiber amplifiers at 1.55 μm in infrared emission region.

  20. Wettability of silicon carbide ceramic by Al2O3/Dy2O3 and Al2O3/Yb2O3 systems

    Institute of Scientific and Technical Information of China (English)

    J.A.da Silva; B.M.Moreschi; G.C.R.Garcia; S.Ribeiro

    2013-01-01

    Wettability is an important phenomenon in the liquid phase sintering of silicon carbide (SiC) ceramics.This work involved a study of the wetting of SiC ceramics by two oxide systems,Al2O3/Dy2O3 and Al2O3/Yb2O3,which have so far not been studied for application in the sintering of SiC ceramics.Five mixtures of each system were prepared,with different compositions close to their respective eutectic ones.Samples of the mixtures were pressed into cylindrical specimens,which were placed on a SiC plate and subjected to temperatures above their melting points using a graphite resistance furnace.The behavior of the melted mixtures on the SiC plate was observed by means of an imaging system using a CCD camera and the sessile drop method was employed to determine the contact angle,the parameter that measures the degree of wettability.The results of variation in the contact angle as a function of temperature were plotted in graphic form which showed that the curves displayed a fast decline and good spreading.All the samples of the two systems presented final contact angles of 40° to 10° indicating their good wetting on SiC in the argon atmosphere.The melted/solidified area and interface between SiC and melted/solidified phase were evaluated by scanning electron microscopy (SEM) and their crystalline phases were identified by X-ray diffraction (DRX).The DRX analysis showed that Al2O3 and RE2O3 reacted and formed the Dy3Al5O12 (DyAg) and Yb3Al5O12 (YbAg) phases.The results indicated that the two systems had a promising potential as additives for the sintering of SiC ceramics.

  1. Effect of cryogenic temperature on spectroscopic and laser properties of Er, Yb-doped potassium-lanthanum phosphate glass

    Science.gov (United States)

    Švejkar, Richard; Šulc, Jan; Němec, Michal; Jelínková, Helena; Nitsch, Karel; Cihlář, Antonín.; Král, Robert; Nejezchleb, Karel; Nikl, Martin

    2017-05-01

    Glass matrix doped with rare-earth ions is a promising laser active medium for high power laser systems. Due to amorphous structure of glasses the absorption and emission spectra lines are broader in comparison with crystalline materials thus pumping radiation can be absorbed efficiently, moreover much broader gain bandwidth is suitable for generation of ultra-short pulses. Another advantage of the glass matrix is the possibility to fabricate large volume ingots and simultaneously preservation of sufficient optical quality. The lower thermal conductivity of glasses can be compensated by geometry of the active medium for instance shaped into fibres or discs. We present temperature dependence of spectroscopic and laser properties of newly developed Er, Yb - doped potassium-lanthanum phosphate glass, which is appropriate for generation of radiation at 1.53 μm. The sample of Er,Yb:KLaP glassy mixture was cut into disc shape with dimensions of 2.5 mm (thickness) and 5 mm (diameter) and its faces were polished plan-parallelly without being anti-reflection coated. The temperature dependence of the transmission and emission spectra Er,Yb:KLaP together with the fluorescence decay time were measured the temperature range from 80 to 400 K. The fluorescence lifetime of manifold 4I13/2 (upper laser level) prolonged and the intensity of up-conversion radiation decreased with decreasing temperature. The longitudinal excitation of Er,Yb:KLaP was carried out by a fibre-coupled laser diode (pulse duration 2 ms, repetition rate 10 Hz, pump wavelength 969 nm). Laser resonator was hemispherical, with flat pumping mirror (HR @ 1.5 μm) and spherical output coupler (R = 98 % @ 1.5 - 1.6 μm). The Er,Yb:KLaP glass laser properties were investigated in the temperature range 80 - 300 K. The highest slope efficiency with respect to absorbed pumped power was 6.1 % at 80 K. The maximum output of peak amplitude power was 0.71 W at 80 K, i.e. 1.2 times higher than at 300 K. Tunability of laser

  2. PHYSICAL VAPOR DEPOSITION OF Er3+:Yb3Al5O12 THIN FILMS FROM SOL-GEL DERIVED TARGETS

    Directory of Open Access Journals (Sweden)

    T. Hlasek

    2016-10-01

    Full Text Available Although ytterbium aluminum garnets (YbAG belong to a group of promising optical materials, no physical method of thin films deposition has been described so far. In this work we present the comparison of two valuable physical deposition techniques: pulsed laser deposition and electron beam evaporation. Erbium (Er3+ doped ytterbium garnet (Er0.005Yb0.995₃Al₅O12 (Er:YbAG thin films were prepared using own sol-gel derived ceramic targets. The phase composition of the films and crystallite size were determined using X-ray diffraction. Microstructure and surface morphology were studied by scanning electron microscopy and atomic force microscopy. Deposition parameters of used methods were optimized; however, both techniques produced amorphous films with insufficient microstructure. The effect of additional annealing on the crystallinity and luminescent properties of erbium ions was studied. A pure infrared emission of Er3+ ions was observed only in samples prepared by pulsed laser deposition with subsequent annealing.

  3. Spatially selective Er/Yb-doped CaF{sub 2} crystal formation by CO{sub 2} laser exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo, E-mail: kslim@chungbuk.ac.kr

    2014-10-30

    Highlights: • Oxyfluoride glass–ceramics containing CaF{sub 2} nanocrystals doped with Er{sup 3+} and Yb{sup 3+} ions were formed on the glass surface by CO{sub 2} laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF{sub 2} nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO{sub 2} laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF{sub 2} and miner Ca{sub 2}SiO{sub 4} nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment.

  4. Spatially selective Er/Yb-doped CaF{sub 2} crystal formation by CO{sub 2} laser exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo, E-mail: kslim@chungbuk.ac.kr

    2015-04-15

    Highlights: • Oxyfluoride glass–ceramics containing CaF{sub 2} nanocrystals doped with Er{sup 3+} and Yb{sup 3+} ions were formed on the glass surface by CO{sub 2} laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF{sub 2} nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO{sub 2} laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF{sub 2} and miner Ca{sub 2}SiO{sub 4} nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment.

  5. Chromaticity modulation of upconversion luminescence in CaSnO{sub 3}:Yb{sup 3+}, Er{sup 3+}, Li{sup +} phosphors through Yb{sup 3+} concentration, pumping power and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Tao, E-mail: tpang@126.com; Lu, Wenhui; Shen, Wujian

    2016-12-01

    CaSnO{sub 3}:Yb{sup 3+}, Er{sup 3+}, Li{sup +} upconverting phosphors are synthesized by a simple solid state method. The doping concentration of Li{sup +} ions is optimized by comparatively studying upconversion luminescence of samples with various Li{sup +} content. The effects of Yb{sup 3+} concentration, pumping power and temperature on chromaticity of upconversion luminescence in CaSnO{sub 3}:Yb{sup 3+}, Er{sup 3+}, Li{sup +} phosphors are investigated, the related mechanisms are discussed and the abilities to modulate chromaticity are evaluated.

  6. 用于波导放大器的Er3+/Yb3+共掺磷酸盐玻璃的性能研究%Properties of Er3+/Yb3+ Codoped Phosphate Glass for Waveguide Amplifiers

    Institute of Scientific and Technical Information of China (English)

    赵士龙; 陈宝玉; 胡俊江; 胡丽丽

    2005-01-01

    通过优化熔融条件和玻璃组份,成功开发出一种新的Er3+/Yb3+共掺磷酸盐玻璃,其在沸水和熔盐中均表现出很好的化学稳定性.通过分析室温下Er3+/Yb3+共掺磷酸盐玻璃的吸收光谱,计算得到了Er3+离子在波长1533 nm处的峰值发射截面和杜得-奥菲而特强度参数;其中Er3+离子在波长1533 nm处的峰值发射截面为0.72×10-20cm2,大于Schott的IOG1玻璃中Er3+离子的峰值发射截面0.67×10-20cm2.通过改变离子交换的条件,获得了1.55μm单模光波导的制作条件;制作的波导传输损耗均小于1 dB/cm.初步的离子交换实验表明,Er3+/Yb3+共掺磷酸盐玻璃WM4完全适合波导放大器的制作.

  7. Laser ablation production of Ba, Ca, Dy, Er, La, Lu, and Yb ions

    CERN Document Server

    Olmschenk, S

    2016-01-01

    We use a pulsed nitrogen laser to produce atomic ions by laser ablation, measuring the relative ion yield for several elements, including some that have only recently been proposed for use in cold trapped ion experiments. For barium, we monitor the ion yield as a function of the number of applied ablation pulses for different substrates. We also investigate the ion production as a function of the pulse energy, and the efficiency of loading an ion trap as a function of radiofrequency voltage.

  8. Photoluminescence properties of rare-earth-doped (Er³⁺,Yb³⁺) Y₂O₃ nanophosphors by a combustion synthesis method.

    Science.gov (United States)

    Kaur, Manmeet; Bisen, D P; Brahme, N; Singh, Prabhjot; Sahu, I P

    2016-05-01

    In this work, we report the synthesis of Y2O3:Er(3+), Y2O3:Yb(3+) and Y2O3:Er(3+),Yb(3+) nanophosphors by the combustion synthesis method using urea as fuel. The doping agents were incorporated in the form of erbium nitrate and ytterbium nitrate. X-Ray diffraction (XRD) patterns revealed that the synthesized particles have a body-centered cubic structure with space group Ia-3. The photoluminescence (PL) properties were investigated after UV and infrared irradiation at room temperature. A strong characteristic emission of Er(3+) and Yb(3+) ions was identified, and the influence of doping concentration on the PL properties was systematically studied. Energy transfer from Yb(3+) to Er(3+) ions was observed in Y2O3 nanophosphors. The obtained result may be useful in potential applications such as bioimaging.

  9. Synthesis and characterization of α-NaYF{sub 4}: Yb, Er nanoparticles by reverse microemulsion method

    Energy Technology Data Exchange (ETDEWEB)

    Gunaseelan, M.; Senthilselvan, J., E-mail: jsselvan@hotmail.com [Department of Nuclear Physics, University of Madras, Chennai, Tamil Nadu (India)

    2016-05-06

    A simple and cost effective reverse microemulsion system was newly designed to synthesis NaYF{sub 4}:20%Yb,2%Er upconverting luminescent nanoparticles. XRD results confirms the cubic structure of NaYF{sub 4} nanophosphor in the as prepared condition without any other impurity phases. The as-prepared sample itself having highly crystalline nanoparticle with well dispersed uniform morphology is the advantage of this reverse microemulsion process. HRTEM images of as prepared and calcined samples revealed spherical nanoclusters morphology with size of ~210 nm and ~245 nm respectively. The characteristic absorption wavelength that occurs at 980 nm due to transition of energy levels {sup 2}F{sub 5/2} to {sup 2}F{sub 7/2} for Yb{sup 3+} rare earth ion in as prepared and calcined upconversion nanoparticle confirms the presence of Yb{sup 3+} by UV-Visible spectroscopy which can act as a sensitizer for photonic upconversion. Therefore the absorption at NIR region and emission spectrum at visible region suggests that NaYF{sub 4}:20%Yb,2%Er is suitable for upcoversion process, due to its optical property and chemical stability this material also be useful for bio imaging applications.

  10. Upconversion photoluminescence properties of SrY2O4:Er3+,Yb3+ under 1550 and 980 nm excitation

    Institute of Scientific and Technical Information of China (English)

    沈显良; 邢明铭; 田莹; 付姚; 彭勇; 罗昔贤

    2016-01-01

    Er3+/Yb3+co-doped SrY2O4 phosphors with high color purity and brightness were successfully synthesized via a solid-state reaction method. Luminescence spectrum studies showed that the main red peaks and the minor green peaks of upconversion emis-sions were located at approximately 634–681 nm and 543–570 nm, respectively, corresponding to the transitions of4F9/2→4I15/2and 4S3/2→4I15/2of Er3+ions. Under the excitation of 980 and 1550 nm lasers, the spectra of all of the samples exhibited similar peak posi-tions but different intensities. When excited by the 980 nm laser, the intensity ratio of red to green emission increased with increasing Yb3+ doping concentration and decreased with increasing excitation power. In the case of 1550 nm excitation, the intensity ratio of red to green emission increased with increasing Yb3+ doping concentration and excitation power, thereby, improving the color purity of the red emission. The intensity of red emission was considerably stronger under 1550 nm excitation than that under 980 nm excitation. Therefore, the color of the proposed phosphors could be efficiently tuned by tailoring both the Yb3+doping concentration and excita-tion power.

  11. Dually functioned core-shell NaYF4:Er(3+)/Yb(3+)@NaYF4:Tm(3+)/Yb(3+) nanoparticles as nano-calorifiers and nano-thermometers for advanced photothermal therapy.

    Science.gov (United States)

    Zhang, Yanqiu; Chen, Baojiu; Xu, Sai; Li, Xiangping; Zhang, Jinsu; Sun, Jiashi; Zheng, Hui; Tong, Lili; Sui, Guozhu; Zhong, Hua; Xia, Haiping; Hua, Ruinian

    2017-09-19

    To realize photothermal therapy (PTT) of cancer/tumor both the photothermal conversion and temperature detection are required. Usually, the temperature detection in PTT needs complicated instruments, and the therapy process is out of temperature control in the present investigations. In this work, we attempt to develop a novel material for achieving both the photothermal conversion and temperature sensing and control at the same time. To this end, a core-shell structure with NaYF4:Er(3+)/Yb(3+) core for temperature detection and NaYF4:Tm(3+)/Yb(3+) shell for photothermal conversion was designed and prepared. The crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, the temperature sensing properties for the NaYF4:Er(3+)/Yb(3+) and core-shell NaYF4:Er(3+)/Yb(3+)@NaYF4:Tm(3+)/Yb(3+) nanoparticles were studied. It was found that the temperature sensing performance of the core-shell nanoparticles did not become worse due to coating of NaYF4:Tm(3+)/Yb(3+) shell. The photothermal conversion behaviors were examined in cyclohexane solution based on the temperature response, the NaYF4:Er(3+)/Yb(3+)@NaYF4:Tm(3+)/Yb(3+) core-shell nanoparticles exhibited more effective photothermal conversion than that of NaYF4:Er(3+)/Yb(3+) nanoparticles, and a net temperature increment of about 7 °C was achieved by using the core-shell nanoparticles.

  12. Impact of codopant ions on 2.5-3.0 μm emission of Er3+:4I11/2→4I13/2 transition in Yb,Er,Eu:LaYSGG crystal

    Science.gov (United States)

    Wang, Yan; Li, Jianfu; Zhu, Zhaojie; You, Zhenyu; Xu, Jinlong; Tu, Chaoyang

    2015-12-01

    The crystal of 1 at% Yb3+, 10 at% Er3+ and 0.1 at% Eu3+ triply doped La0.3Y2.7Sc2Ga3O12 (abbr. as Yb,Er,Eu:LaYSGG) was grown for the first time by using a Czochralski technique. Its absorption, near-infrared and mid-infrared fluorescence spectra, as well as the fluorescence decay curves of Er:4I13/2 and 4I11/2 levels were measured at room temperature. The spectroscopic properties including the absorption and emission cross-sections as well as the fluorescence lifetimes of the title crystal were revealed and compared with 10 at% Er3+:Y3Sc2Ga3O12 crystal. Spectral analyses show that the sensitization of Yb3+ ion leads to an enhanced 2.5-3.0 μm emission corresponding to Er3+:4I11/2→4I13/2 transition in the grown crystal, meanwhile, the depopulation of Eu3+ ion from Er3+ inhibits the self-termination effect successfully. The energy transfer mechanism was discussed; the energy transfer efficiencies of Yb3+→Er3+ (ET1) and Er3+→Eu3+ (ET2) were estimated to be 94.8% and 93.9%, respectively. The results indicates that Yb,Er,Eu:LaYSGG crystal is a good candidate for LD pumped mid-infrared laser.

  13. Ion-exchanged Er3+/Yb3+ co-doped waveguide amplifiers longitudinally pumped by broad area lasers.

    Science.gov (United States)

    Donzella, V; Toccafondo, V; Faralli, S; Di Pasquale, F; Cassagnettes, C; Barbier, D; Figueroa, H Hernandez

    2010-06-07

    A multimode pumping scheme for Er(3+)/Yb(3+) co-doped waveguide amplifiers based on broad area lasers at around 980 nm is presented. The proposed amplifier is fabricated by ion-exchange (IE) technique on silicate and phosphate glasses. The highly efficient energy transfer from Yb(3+) to Er(3+) ions, combined with the use of low cost and high power broad area laser, allows the realization of high performance and cost-effective integrated amplifiers. The structure has been designed and numerically studied using a 3D finite element modelling tool, and over 3 dB/cm small signal gain has been predicted for an optimized amplifier. Preliminary characterization of an amplifier structure provides a first experimental evidence of the novel multimode longitudinal pumping.

  14. Infrared to near-infrared and visible upconversion photoluminescence of LiYbF4∶Er3+ nanorods

    Institute of Scientific and Technical Information of China (English)

    LIU Wangdong; LI Wenbin; TANG Haibo; ZHAO Mingzhuo

    2013-01-01

    Colloidal LiYbF4∶Er3+ nanorods were synthesized in an aqueous system which had the ratio of length to diameter of~2.These LiYbF4∶Er3+ nanorods emitted intense upconversion light under excitation of infrared at 1488 nm.Importantly,the intensities of two-and three-photon anti-Stokes upconversion PL bands were observed which were comparable to that of the Stokes emission under excitation with low power density.The plots of excitation power density versus emission intensity indicated that all the emissions centered at 549,668,and 978 nm took a two-photon upconversion process.However,it could be simply deduced that the energy of two photons of 1488 nm were inadequate to produce a photon of 668 or 549 nm.For this conflict,the shape and saturation effects in the intermediate energy states were introduced to demonstrate the corresponding upconversion processes.

  15. Laser Diode Pumped 1.54μm Er:Yb:Phosphate Glass Continuous Wave Compact Laser

    Institute of Scientific and Technical Information of China (English)

    孟凡臻; 宋峰; 张潮波; 丁欣; 商美茹; 张光寅

    2003-01-01

    We report a cw Er3+ :Yb3+ co-doped phosphate glass laser pumped by a laser diode. The maximum output power of 78.3mW and a slope efficiency of 15.25% were achieved. The laser spectral region was from 1532nm to 1535nm, with the peak laser wavelength at 1534nm. The laser modes and time stability were also measured.The thermal effect had little influence on the output in our experiment.

  16. Upconverting PAAm/PNIPAM/NaYF{sub 4}:Yb:Er hydrogel with enhanced luminescence temperature sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jiachang; He, Benzhao; Cheng, Zehong; Zhou, Li, E-mail: zhouli@glut.edu.cn

    2015-04-15

    We present a one-step approach to combine the functional features of upconverting NaYF{sub 4}:Yb:Er nanoparticles and thermosensitive poly(N-isopropylacrylamide) (PNIPAM) for luminescence thermometry. Dual-functional hydrogel that simultaneously possesses strong upconversion luminescence (UL) and temperature responsibility was fabricated based on the crosslinking of poly(acrylamide) in the presence of PNIPAM and NaYF{sub 4}:Yb:Er nanoparticles. The obtained hydrogel exhibited reversibly temperature-dependent UL and highly enhanced sensibility. The luminescence temperature sensitivity reached 1.9% per °C and 0.7% per °C in the range of 27–33 °C and 35–45 °C, respectively. The maximum sensitivity could even reach 26.5% per °C in the range of 33–35 °C. Considering the facile fabrication process and fine luminescence thermometry performance, this study thus opens up new opportunities for preparing highly sensitive temperature sensors. - Highlights: • One-step fabrication of upconverting and thermosensitve PAAm/PNIPAM/NaYF{sub 4}:Yb:Er hydrogel is reported. • The combination of functional features of NaYF{sub 4}:Yb:Er upconversion nanoparticles (UCNPs) and thermosensitve PNIPAM can efficiently enhance the luminescence temperature sensitivity of UCNPs. • The luminescence temperature sensitivity of hydrogel can respectively reach 1.9% per °C and 0.7% per °C in the range of 27–33 °C and 35–45 °C. • The maximum sensitivity can even reach 26.5% per °C in range of 33–35 °C.

  17. Fabrication of NaYF4:Yb,Er Nanoprobes for Cell Imaging Directly by Using the Method of Hydrion Rivalry Aided by Ultrasonic

    Science.gov (United States)

    Li, Zhihua; Miao, Haixia; Fu, Ying; Liu, Yuxiang; Zhang, Ran; Tang, Bo

    2016-10-01

    A novel method of fabricating water-soluble bio-probes with ultra-small size such as NaYF4:Yb,Er (18 nm), NaGdF4:Yb,Er (8 nm), CaF2:Yb,Er (10 nm), PbS (7 nm), and ZnS (12 nm) has been developed to provide for the solubility switch of nanoparticles from oil-soluble to water-soluble in terms of hydrion rivalry aided by ultrasonic. Using NaYF4:Yb,Er (18 nm) as an example, we evaluate the properties of as-prepared water-soluble nanoparticles (NPs) by using thermogravimetric analyses (TGA), Fourier transform infrared spectroscopy (FTIR), zeta potential ( ζ) testing, and 1H nuclear magnetic resonance (1HNMR). The measured ζ value shows that the newly prepared hydrophilic NaYF4:Yb,Er NPs are the positively charged particles. Acting as reactive electrophilic moiety, the freshly prepared hydrophilic NaYF4:Yb,Er NPs have carried out the coupling with amino acids and fluorescence labeling and imaging of HeLa cells directly. Experiments indicate that the method of hydrion rivalry aided by ultrasonic provides a simple and novel opportunity to transform hydrophobic NPs into hydrophilic NPs with good reactivity, which can be imaging some specific biological targets directly.

  18. Yb,Er-doped CeO2 nanotubes as an assistant layer for photoconversion-enhanced dye-sensitized solar cells

    Science.gov (United States)

    Zhao, Rongfang; Huan, Long; Gu, Peng; Guo, Rong; Chen, Ming; Diao, Guowang

    2016-11-01

    Yb,Er-doped CeO2 nanotubes were successfully synthesized using Ag nanowires as a hard template via a facile hydrothermal reaction and subsequent calcination and leaching processes. Yb,Er-doped CeO2 nanotubes as a promising assistant layer were investigated to determine theirs photovoltaic properties in an effort to enhance the power conversion efficiency of dye-sensitized solar cells (DSSCs). The influence factors of photoelectric properties of CeO2:Yb,Er NTs, including diameter of nanotubes, hydrothermal time, calcination temperature, and elements doping, have been studied. Compared with pristine P25 photoanode, the DSSCs fabricated by CeO2:Yb,Er nanotubes and P25 exhibited a power conversion efficiency (η) of 8.67%, an increase of 34%, and incident photo-to-electric conversion efficiency (IPCE) of 92.96%, an increase of 48.83%, which evidence that CeO2:Yb,Er NTs are a promising assistant photoanode material for DSSCs. The enhance mechanism of CeO2:Yb,Er nanotubes has been further revealed according to experimental results.

  19. Crystal field effects in the intermetallic R Ni3Ga9 (R =Tb , Dy, Ho, and Er) compounds

    Science.gov (United States)

    Silva, L. S.; Mercena, S. G.; Garcia, D. J.; Bittar, E. M.; Jesus, C. B. R.; Pagliuso, P. G.; Lora-Serrano, R.; Meneses, C. T.; Duque, J. G. S.

    2017-04-01

    In this paper, we report temperature-dependent magnetic susceptibility, electrical resistivity, and heat-capacity experiments in the family of intermetallic compounds R Ni3Ga9 (R = Tb, Dy, Ho, and Er). Single-crystalline samples were grown using Ga self-flux method. These materials crystallize in a trigonal ErNi3Al9 -type structure with space group R 32 . They all order antiferromagnetically with TNK . The anisotropic magnetic susceptibility presents large values of the ratio χeasy/χhard indicating strong crystalline electric-field (CEF) effects. The evolution of the crystal-field scheme for each R was analyzed in detail by using a spin model including anisotropic nearest-neighbor Ruderman-Kittel-Kasuya-Yosida interaction and the trigonal CEF Hamiltonian. Our analysis allows one to understand the distinct direction of the ordered moments along the series—the Tb-, Dy-, and Ho-based compounds have the ordered magnetic moments in the easy ab plane and the Er sample magnetization easy axis is along the c ̂ direction.

  20. Photoluminescence of rare earth ions (Er{sup 3+}, Yb{sup 3+}) in a porous silicon matrix

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, Sergey A. [Moscow State Lomonosov University, Faculty of Physics, Leninskie Gory 1, 119991 Moscow (Russian Federation); Rösslhuber, Roland [Technische Universität München, Arcisstrasse 21, D-85748 München (Germany); Zhigunov, Denis M., E-mail: dmzhigunov@physics.msu.ru [Moscow State Lomonosov University, Faculty of Physics, Leninskie Gory 1, 119991 Moscow (Russian Federation); Latukhina, Natalia V. [Samara State University, Department of Physics, Akad. Pavlova Str. 1, 443011 Samara (Russian Federation); Timoshenko, Victor Yu. [Moscow State Lomonosov University, Faculty of Physics, Leninskie Gory 1, 119991 Moscow (Russian Federation)

    2014-07-01

    Layers of porous silicon (por-Si) with incorporated rare earth (RE) ions of erbium (Er) and ytterbium (Yb) were prepared by using electrochemical etching of crystalline silicon (c-Si) wafers followed by infiltration with RE ions from solution and subsequent high temperature annealing in air. The prepared samples exhibited room temperature photoluminescence (PL) of both Si nanocrystals and RE ions in the spectral regions of 0.6–0.9 μm and 0.98–1.5 μm, respectively. The PL intensities of RE ions in por-Si layers grown on c-Si substrates with textured surface were stronger than those for the polished ones. The observed pump power dependencies of the PL intensity were non-linear and were explained by a phenomenological model, which accounted for (i) the energy transfer from excitons confined in Si nanocrystals to Er{sup 3+} ions located in the surrounding silicon oxide (Förster transfer) and (ii) a cooperative process of the simultaneous excitation of two Yb{sup 3+} ions (quantum-cutting like process). The obtained results are promising in view of possible applications of por-Si:(Er,Yb) in light-emitting devices for near-infrared spectral region. - Highlights: • A simple method to produce rare earth doped materials is represented. • Photoluminescence properties are investigated. • Photoluminescence pump power dependencies were simulated using a phenomenological model.

  1. Intense frequency upconversion fluorescence of Er3+/Yb3+ co-doped lithium-strontium-lead-bismuth glasses

    Institute of Scientific and Technical Information of China (English)

    Hongtao Sun; Shiqing Xu; Baoyu Chen; Shixun Dai; Shilong Zhao; Lili Hu; Zhonghong Jiang

    2005-01-01

    @@ Infrared-to-visible upconversion fluorescence of Er3+/Yb3+ co-doped lithium-strontium-lead-bismuth (LSPB) glasses for developing potential upconversion lasers has been studied under 975-nm excitation.Based on the results of energy transfer efficiency and upconversion spectra, the optimal Yb3+-Er3+ concentration ratio is found to be 5∶1. Intense green and red emissions centered at 525, 546, and 657 nm,corresponding to the transitions 2H11/2→4I15/2, 4S3/2→4I15/2, and 4F9/2 → 4I15/2, respectively, were observed. The quadratic dependence of the 525-, 546-, and 657-nm emissions on excitation power indicates that a two-photon absorption process occurs under 975-nm excitation. The high-populated 4I11/2 level is supposed to serve as the intermediate state responsible for the upconversion processes. The intense upconversion luminescence of Er3+/Yb3+ co-doped LSPB glasses may be a potentially useful material for developing upconversion optical devices.

  2. Magnetic properties of R/sub 3/Rh/sub 2/ compounds with R = Gd, Tb, Dy, Ho and Er

    Energy Technology Data Exchange (ETDEWEB)

    Gignoux, D. (Centre National de la Recherche Scientifique, 38 - Grenoble (France). Lab. Louis Neel); Gomez-Sal, J.C.; Aramburu-Zabala, J.A. (Santander Univ. (Spain). Facultad de Ciencias); Paccard, D. (Universite de Savoie, 74 - Annecy-le-Vieux (France). Lab. Structure de la Matiere)

    1984-04-01

    Bulk magnetic measurements performed on polycrystalline samples of the tetragonal compounds R/sub 3/Rh/sub 2/ with R = Gd, Tb, Dy, Ho and Er are presented. All the compounds are ferromagnetic at low temperature. However in Tb/sub 3/Rh/sub 2/ an antiferromagnetic behaviour is observed between 14 and 24 K. In Gd/sub 3/Rh/sub 2/, where the magnetocrystalline anisotropy must be negligible, it seems that the magnetic structure is not collinear. In the other compounds the observed properties essentially result from indirect exchange interactions and crystal field effects acting on the rare earth ions which lie in low symmetry sites.

  3. Anisotropy in the paramagnetic phase of RAl/sub 2/ cubic intermetallic compounds (R = Tb, Dy, and Er)

    Energy Technology Data Exchange (ETDEWEB)

    del Moral, A.; Ibarra, M.R.; Abell, J.S.; Montenegro, J.F.D.

    1987-05-01

    In this paper it is shown that the anisotropy in the paramagnetic phase is a useful characteristic when used to single out high-rank susceptibility tensor components in the paramagnetic regime of cubic crystals. Application of this technique to RAl/sub 2/ compounds (R = Tb,Dy,Er) allows the determination of longitudinal and transverse (in the form of linear combinations) fourth- and sixth-rank paramagnetic susceptibilities. The use of the fourth-rank longitudinal susceptibility allows quadrupolar pair interactions in these compounds to be probed.

  4. SrMoO4:Er3+-Yb3+ upconverting phosphor for photonic and forensic applications

    Science.gov (United States)

    Soni, Abhishek Kumar; Rai, Vineet Kumar

    2016-08-01

    The Er3+-Yb3+ codoped strontium molybdate (SrMoO4) phosphors have been synthesized via chemical co-precipitation method by adding ammonium hydroxide as a base reagent. The phase, crystal structure and formation of spindle-like particles present in the prepared phosphors have been recognized by using the X-ray powder diffraction (XRPD) and Field emission scanning electron microscopy (FE-SEM) techniques. The Fourier transform infrared (FTIR) spectroscopy of the developed phosphors has been analyzed to mark the different functional groups present in synthesized phosphors. The multicolour upconversion emissions observed upon excitation with 980 nm and 808 nm laser diode have been explained on the basis of dopants ions concentration, pump power dependence, energy level structure and decay curve analysis. The colour co-ordinate study confirmed that the codoped phosphor emits non-tunable green colour when excited with the 980 nm laser diode, whereas it shows the colour tunability from yellow to green region upon excitation with the 808 nm laser diode. The applicability of non-tunable green colour emission has been demonstrated in the security ink and latent finger print detection. This shows the utility of the developed phosphors in the photonic and forensic applications.

  5. Controlled synthesis of β-NaYF{sub 4}:Yb, Er microphosphors and upconversion luminescence property

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ruisen; Ma, Tingting; Qiu, Baotian; Li, Xia, E-mail: Lix@qust.edu.cn

    2017-06-15

    NaYF{sub 4}:Yb{sup 3+}/Er{sup 3+} with different phases, morphologies, and luminescent properties were synthesized using a facial hydrothermal method. The as-obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) pattern, and photoluminescence (PL). The XRD results indicated that ethylene diamine tetraacetic acid (EDTA) and citrate play an important role in phase transition at low reaction temperatures. SEM images revealed that samples morphologies can be changed from irregular shapes to regular microprisms by EDTA and citrate. TEM images showed that the diameter of samples synthesized at 120 °C without any chelating agents is ∼50 nm. HRTEM indicated that the crystal grows along the [111] plane. The selected area electron diffraction (SAED) pattern showed that the nanoparticles have a good single-crystalline structure. FL spectra revealed that citrate can reduce the luminescence intensity at any reaction temperature. However, EDTA can improve optical properties at low reaction temperatures. - Highlights: • Effect of EDTA and citrate on upconversion luminescence was investigated. • EDTA & citrate can promote phase transition from cubic to hexagonal. • EDTA can improve the emission intensity at low reaction temperatures. • EDTA & citrate play a role in changing crystals’ growth direction.

  6. White light upconversion emissions in Er3+/Tm3+/Yb3+ tridoped oxyfluoride glass

    Science.gov (United States)

    Guan, Xiaoping; Xu, Wei; Zhu, Shuang; Song, Qiutong; Wu, Xijun; Liu, Hailong

    2015-10-01

    Rare earth ions doped glasses producing visible upconversion emissions are of great interest due to their potential applications in the photonics filed. In fact, practical application of upconversion emissions has been used to obtain color image displays and white light sources. However, there are few reports on the thermal effect on tuning the emission color of the RE doped materials. In this work, the Er3+/Tm3+/Yb3+ tridoped oxyfluoride glasses were prepared through high temperature solid-state method. Under a 980 nm diode laser excitation, the upconversion emissions from the samples were studied. At room-temperature, bright white luminescence, whose CIE chromaticity coordinate was about (0.28, 0.31), can be obtained when the excitation power was 120 mW. The emission color was changed by varying the intensity ratios between RGB bands, which are strongly dependent on the rare earth ions concentration. The temperature dependent color emissions were also investigated. As temperature increased, the intensities for the emission bands presented different decay rates, finally resulting in the changing of the CIE coordinate. When the temperature was 573 K, white light with color coordinate of (0.31, 0.33) was achieved, which matches well with the white reference (0.33, 0.33). The color tunability, high quality of white light and intense emission intensity make the transparent oxyfluoride glasses excellent candidates for applications in solid-state lighting.

  7. RESEARCH OF THERMO-OPTICAL INHOMOGENEITIES IN Yb-Er GLASS AT DIODE PUMPING

    Directory of Open Access Journals (Sweden)

    V. Khramov

    2016-03-01

    Full Text Available Subject of Research. Investigation method of thermo-optical distortions in solid-state lasers was developed and presented. The method can be easily used for research of small diameter (approximately 2 mm active elements. Method. The experimental method described in this paper is based on the registration of deviation of the energy center of the probe beam passing through the thermally stressed active element. Main Results. We have presented experimental results of the thermal lens optical power research in the active element made of Yb-Er glass pumped transversely by a laser diode in the following modes: without generating, free-running and Q-switching. We have submitted obtained dependences of the optical power on the pumping energy. The measurements have been performed for the two polarization components at two wavelengths (632.8 nm and 1550 nm showing the absence of explicit astigmatism of the thermal lens. Practical Relevance. Knowledge of the thermal regime of such lasers gives the possibility for more precise calculation of the resonator parameters in terms of the thermal lens occurrence.

  8. Fabrication and gain performance of Er3+/Yb3+-codoped tellurite glass fiber

    Institute of Scientific and Technical Information of China (English)

    DAI Shixun; XU Tiefeng; NIE Qiuhua; SHEN Xiang; WANG Xunsi

    2008-01-01

    Er3+/Yb3+-codoped TeO2-ZnO-BaO-La2O3 tellurite glass fiber was fabricated by rotation and rod-in-tube technologies. The ther-mal stability and optical refractive index of the core and cladding glasses were determined by DTA and optical coupler, respectively. The av-erage background loss of tellurite glass fiber was 1.8 dB/m at 1310 nm. Optical microscopy and field emission scanning electron microscope (FESEM) were used to study structural characteristics of preforms and optical fibers. The main loss of tellurite glass fiber could be attributed to scatter centre due to core-cladding interface defects. The amplifier performance of tellurite glass fiber was investigated by pumping with 980 nm laser diode (LD). The gain coefficient and maximum signal gain were 0.21 dB/mW and 10 dB, respectively, for a pumping power of 120 mW. Gains exceeding 5 dB were obtained over 30 um bandwidth from 1535 to 1565 nm. The minimum noise figure was 4.8 dB at 1557 um.

  9. Modification on upconversion luminescence of Er3 +-Yb3 + co-doped BiOCl semiconductor nanosheets through interaction between nanohost and doping lanthanide

    Science.gov (United States)

    Xu, Zuyuan; Li, Yongjin; Song, Yapai; Zhang, Xiangzhou; Hu, Rui; Qiu, Jianbei; Yang, Zhengwen; Song, Zhiguo

    2017-04-01

    We reported the upconversion luminescence (UCL) properties of Er3 +-Yb3 + co-doped BiOCl semiconductor nanosheets synthesized by hydrothermal method. Under 980 nm excitation, the red and green UCL of Er3 + ions were observed to be populated by a four and three-photon process in the case of absent or low concentration Yb3 + dopant. However, an increase of Yb3 + dopants show a completely opposite effect on the emission intensity of red and green one, accompanying with the change of upconverting process. It indicates that the red-shifting absorption edge of semiconductor and the super saturation UC processes involved with Yb3 + and Er3 + doping in BiOCl semiconductor nanosheets, respectively, are mainly responsible for the above UC phenomena.

  10. Enhancement of 1.5 μm emission under 980 nm resonant excitation in Er and Yb co-doped GaN epilayers

    Science.gov (United States)

    Wang, Q. W.; Li, J.; Lin, J. Y.; Jiang, H. X.

    2016-10-01

    The Erbium (Er) doped GaN is a promising gain medium for optical amplifiers and solid-state high energy lasers due to its high thermal conductivity, wide bandgap, mechanical hardness, and ability to emit in the highly useful 1.5 μm window. Finding the mechanisms to enhance the optical absorption efficiency at a resonant pump wavelength and emission efficiency at 1.5 μm is highly desirable. We report here the in-situ synthesis of the Er and Yb co-doped GaN epilayers (Er + Yb:GaN) by metal-organic chemical vapor deposition (MOCVD). It was observed that the 1.5 μm emission intensity of the Er doped GaN (Er:GaN) under 980 nm resonant pump can be boosted by a factor of 7 by co-doping the sample with Yb. The temperature dependent PL emission at 1.5 μm in the Er + Yb:GaN epilayers under an above bandgap excitation revealed a small thermal quenching of 12% from 10 to 300 K. From these results, it can be inferred that the process of energy transfer from Yb3+ to Er3+ ions is highly efficient, and non-radiative recombination channels are limited in the Er + Yb:GaN epilayers synthesized in-situ by MOCVD. Our results point to an effective way to improve the emission efficiency of the Er doped GaN for optical amplification and lasing applications.

  11. Up-conversion emissions of Er3+-Yb3+ codoped Al2O3 nanoparticles by the arc discharge synthesis method

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Er3+-Yb3+ codoped Al2O3 nanoparticles with an average particle size of about 50 nm have been synthesized by an arc discharge synthesis method. The green and red up-conversion emissions centered at about 526, 547 and 677 nm, corresponding respectively to the 2H11/2→4I15/2, 4S3/2→4I15/2 and 4 F9/2→4I15/2 transitions of Er3+, were detected by a 978-nm semiconductor laser diode excitation. The Annealing has evident effect on the up-conversion emissions of the samples: The red up-conversion emission is noticeable before annealing; however, the green up-conversion emission becomes predominant after annealing. The mixture of (Er,Yb)3Al5O12 and α-(Al,Er,Yb)2O3 phases is more favorable for green up-conversion emissions due to an enhancement of the ESA (I) of 4I11/2+a photon→4F7/2 and ET (III) of 2F5/2(Yb3+)+4I11/2(Er3+)→2F7/2(Yb3+)+4F7/2(Er3+) processes. The two-photon absorption up-conversion process is involved in the green and red up-conversion emissions. The results have proved that arc discharge synthesis is a new promising preparation technology for optical materials.

  12. Microwave sol-gel derived NaCaGd(MoO4)3:Er3+/Yb3+ phosphors and their upconversion photoluminescence properties

    Science.gov (United States)

    Lim, Chang Sung

    2016-05-01

    Ternary molybdate NaCaGd1-x(MoO4)3:Er3+/Yb3+ phosphors with the proper doping concentrations of Er3+ and Yb3+ (x = Er3+ + Yb3+, Er3+ = 0, 0.05, 0.1, 0.2 and Yb3+ = 0, 0.2, 0.45) were successfully synthesized by microwave sol-gel method for the first time. Well-crystallized particles formed after heat-treatment at 900 °C for 16 h showed a fine and homogeneous morphology with particle sizes of 3-5 μm. The optical properties were examined comparatively using photoluminescence emission and Raman spectroscopy. Under excitation at 980 nm, the doped particles exhibited a strong 525-nm emission band, a weak 550-nm emission band in the green region, which correspond to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions, and a very weak 655-nm emission band in the red region, which corresponds to the 4F9/2 → 4I15/2 transition. The optimal Yb3+:Er3+ ratio was obtained to be 9:1, as indicated by the composition-dependent quenching effect of Er3+ ions. The pump power dependence of upconversion emission intensity and Commission Internationale de L'Eclairage chromaticity coordinates of the phosphors were evaluated in detail.

  13. The effect of pressure on the magnetic susceptibility of RInCu4 (R = Gd, Er and Yb)

    Science.gov (United States)

    Svechkarev, I. V.; Panfilov, A. S.; Dolja, S. N.; Nakamura, H.; Shiga, M.

    1999-06-01

    The magnetic susceptibility of the intermetallic compounds RInCu4 (R = Gd, Er and Yb) was measured under helium gas pressure up to 2 kbar at the fixed temperatures 78, 150 and 300 K. For YbInCu4, which exhibits a first-order valence phase transition at TVicons/Journals/Common/simeq" ALT="simeq" ALIGN="TOP"/>40 K, the Grüneisen parameter for the Kondo energy, icons/Journals/Common/Omega" ALT="Omega" ALIGN="TOP"/>Kicons/Journals/Common/equiv" ALT="equiv" ALIGN="TOP"/>-dlnTK/dlnV = -32, is large and typical for Ce-based heavy-fermion systems in magnitude but opposite in sign. The effect of atomic disorder is discussed on the basis of the data for a chemically disordered sample; the pressure effect at T = 78 K is strongly enhanced due to the spatial dispersion of pressure-sensitive TV, and hence dTV/dP = -2.0 K kbar-1 is obtained by assuming a Gaussian distribution of TV. On the basis of an extrapolation of the experimental pressure dependence, a (P,T) phase diagram is proposed for YbInCu4. Reference compounds with stable f moments, GdInCu4 and ErInCu4, show negligible pressure dependences of the susceptibility.

  14. Importance of suppression of Yb(3+) de-excitation to upconversion enhancement in β-NaYF4: Yb(3+)/Er(3+)@β-NaYF4 sandwiched structure nanocrystals.

    Science.gov (United States)

    Xiang, Guotao; Zhang, Jiahua; Hao, Zhendong; Zhang, Xia; Pan, Guo-Hui; Luo, Yongshi; Lü, Wei; Zhao, Haifeng

    2015-04-20

    Nanosized Yb(3+) and Er(3+) co-doped β-NaYF4 cores coated with multiple β-NaYF4 shell layers were synthesized by a solvothermal process. X-ray diffraction and scanning electron microscopy were used to characterize the crystal structure and morphology of the materials. The visible and near-infrared spectra as well as the decay curves were also measured. A 40-fold intensity increase for the green upconversion and a 34-fold intensity increase for the red upconversion were observed as the cores are coated with three shell layers. The origin of the upconversion enhancement was studied on the basis of photoluminescence spectra and decay times. Our results indicate that the upconversion enhancement in the sandwiched structure mainly originates from the suppression of de-excitation of Yb(3+) ions. We also explored the population of the Er(3+4)F9/2 level. The results reveal that energy transfer from the lower intermediate Er(3+4)I13/2 level is dominant for populating the Er(3+4)F9/2 level when the nanocrystal size is relatively small; however, with increasing nanocrystal size, the contribution of the green emitting Er(3+4)S3/2 level for populating the Er(3+4)F9/2 level, which mainly comes from the cross relaxation energy transfer from Er(3+) ions to Yb(3+) ions followed by energy back transfer within the same Er(3+)-Yb(3+) pair, becomes more and more important. Moreover, this mechanism takes place only in the nearest Er(3+)-Yb(3+) pairs. This population route is in good agreement with that in nanomaterials and bulk materials.

  15. Spectroscopic properties of tellurite glasses co-doped with Er{sup 3+} and Yb{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Leal, J.J. [Instituto Politécnico Nacional CICATA-Unidad Altamira, Tamaulipas 89600 (Mexico); Narro-García, R., E-mail: roberto.narro@gmail.com [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, A.P. 1-1010, Querétaro 76000, Querétaro México (Mexico); Desirena, H. [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37150 (Mexico); Marconi, J.D. [Universidade Federal do ABC, SP (Brazil); Rodríguez, E. [Instituto Politécnico Nacional CICATA-Unidad Altamira, Tamaulipas 89600 (Mexico); Linganna, K. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); De la Rosa, E. [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37150 (Mexico)

    2015-06-15

    Spectroscopic characterization of Er{sup 3+}/Yb{sup 3+} co-doped tellurite glasses 70.8TeO{sub 2}–5Al{sub 2}O{sub 3}–13K{sub 2}O–(11−x)–BaO–0.2Er{sub 2}O{sub 3}–xYb{sub 2}O{sub 3}, where x=0, 0.4, 0.8, 1.2 and 2 mol% has been carried out through X-ray diffraction, Raman, absorption and luminescence spectra. The Judd–Ofelt intensity parameters were calculated for 0.2 mol% Er{sup 3+}-doped glass and are used to evaluate radiative properties such as transition probabilities, branching ratios and radiative lifetime. The emission cross-section of the {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition has been calculated from the absorption data using McCumber's theory. The emission intensity of both, visible and infrared signals as a function of Yb{sub 2}O{sub 3}, have been studied under 980 nm and 375 nm laser excitation. The physical mechanisms responsible for both, visible and infrared signals in the tellurite samples have been explained in terms of the energy transfer and excited state absorption process. The FWHM of the {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition as a function of Yb{sub 2}O{sub 3} mol% and distance (δ) between the laser focusing point and the end-face of the glass has been reported. It was observed both, experimentally and numerically, a change in the FWHM with variations of δ less than 8 mm. The latter was attributed to the radiation trapping effect. - Highlights: • Er{sup 3+}/Yb{sup 3+} co-doped tellurite glasses were fabricated by the melt-quenching technique. • The structural, thermal and optical properties of the tellurite glasses were studied. • The radiation trapping effect has been observed in small tellurite glass samples. • Tellurite glasses could be a potential material for fiber fabrication.

  16. Raman spectra and structural properties of hexagonal Yb{sub 1-x}Dy{sub x}MnO{sub 3} (x = 0, 0.05 and 0.1)

    Energy Technology Data Exchange (ETDEWEB)

    Sattibabu, Bhumireddi; Das, D. [School of engineering Sciences and Technology, University of Hyderabad, Hyderabad-500 046 (India); Bhatnagar, Anil K., E-mail: anilb42@gmail.com [School of engineering Sciences and Technology, University of Hyderabad, Hyderabad-500 046 (India); School of Physics, University of Hyderabad, Hyderabd-500 046 (India)

    2016-05-23

    Single phase Yb{sub 1-x}Dy{sub x}MnO{sub 3} (x= 0, 0.05 and 0.1) samples are prepared by a solid state reaction method. X-ray powder diffraction shows that all samples crystallize in the hexagonal phase with P6{sub 3}cm space group. The structural analysis shows there is increase in lattice parameter c and cell volume of the hexagonal unit cell with Dy substitution and the average bond length between Mn-O increases. Raman spectra show that the phonon peaks of Yb{sub 1-x}Dy{sub x}MnO{sub 3} slightly shift to lower frequencies with doping.

  17. Growth of Er3+/Yb3+ co-doped CaMoO4 thin film by a spray coating and its upconverting luminescence.

    Science.gov (United States)

    Chung, Jun Ho; Kang, Suk Hyun; Shim, Kwang Bo; Cho, Hyun; Hwang, Seok Min; Lee, Jae Bin; Ka, Dong Hyun; Kim, Tae Wan; Lee, Jung-Il; Ryu, Jeong Ho

    2014-10-01

    Polycrystalline Er3+/Yb3+ co-doped CaMoO4 (CaMoO4:Er3+/Yb3+) film was successfully fabricated by a spray coating method. Crystal structure, surface morphology and upconversion (UC) luminescent properties were investigated. Under 980-nm excitation, CaMoO4:Er3+/Yb3+ film exhibited strong green UC emissions at 530 and 550 nm (2H,11/2 --> 4S3/2 - 4I15/2) visible to the naked eye with a weak red emission near 660 nm (4F9/2 --> 4I15/2) corresponding to the intra 4f transitions of Er3+. A possible UC mechanism related to the pump-power dependence is discussed in detail.

  18. Effects of trisodium citrate on morphology of β-NaGd{sub 1-x}Yb{sub x}F{sub 4}:Er{sup 3+} nanocrystals: role of Yb{sup 3+} concentration

    Energy Technology Data Exchange (ETDEWEB)

    Lue, Mengyun; Guan, Tengpeng; Li, Ai-Hua; Sun, Zhijun [Xiamen University, Department of Physics, Xiamen, Fujian (China)

    2015-10-15

    In solvothermal synthesis of Er{sup 3+}-doped NaGd{sub 1-x}Yb{sub x}F{sub 4} nanocrystals, morphology of the nanoparticles is dependent on the molar ratio of the chelating agent (e.g., trisodium citrate) to the lanthanide ions. Usually, addition of chelating agent is reported to be effective only when the molar ratio is below a critical value usually around 1 for the preparation of Er{sup 3+}- and Yb{sup 3+}-doped NaYF{sub 4} nanocrystals. In this work, we found that, by increasing the Yb{sup 3+} concentration, the critical molar ratio can be up to more than 4 in the preparation of Er{sup 3+}-doped NaGd{sub 1-x}Yb{sub x}F{sub 4} nanocrystals, which provides a new route to control the nanoparticles' size. The result is particularly useful for the synthesis of small Er{sup 3+}-doped NaGd{sub 1-x}Yb{sub x}F{sub 4} nanocrystals with high concentration of the Yb{sup 3+} dopant. We also investigated mechanisms on the formation of such particles (β-NaGd{sub 0.3}Yb{sub 0.7}F{sub 4}:Er{sup 3+}) with large size in a sub-micrometer scale, i.e., the aggregation-induced crystal growth. In addition, upconversion luminescence properties of the powdery samples were studied, which is shown to be dependent both on size of the nanoparticles and on dosage of the trisodium citrate. (orig.)

  19. Observation of upconversion white light and ultrabroad infrared emission in YbAG:Ln3+ (Ln = Nd, Sm, Tb, Er)

    Science.gov (United States)

    Zhu, Yongsheng; Cui, Shaobo; Liu, Mao; Liu, Xuyan; Lu, Cheng; Xu, Xiumei; Xu, Wen

    2015-07-01

    We report on the intense white-light upconversion and ultrabroad infrared (IR) emission for the sol-gel synthesis of Yb3Al5O12 (YbAG):Ln3+ (Ln = Nd, Sm, Tb, Er) following excitation with low-energy near-infrared light (λex = 980 nm). Sufficient cross relaxations and photon avalanches play important roles in the formation of efficient visible and IR broad bands. The brightness of white-light upconversion was 6.2 × 104 cd/m2 at a laser power of 1.47 W, and the IR broad bands (1200-1700 nm) covered all the bands in optical communication media, which indicates that the material might be promising for the development of devices such as white lasers, LEDs, and integrated waveguides.

  20. Up-conversion luminescence and optical temperature sensing behaviour of Yb3+/Er3+ codoped CaWO4 material

    Science.gov (United States)

    Cheng, Xuerui; Yang, Kun; Wang, Jiankun; Yang, Linfu; Cheng, Xiaoshuai

    2016-08-01

    Present article report on structural and optical properties of Er3+/Yb3+ codoped CaWO4 phosphors. Structural properties are explored using XRD and Raman technologies. The upconversion emission has been investigated with 980 nm excitation. The upconversion emission intensity is dependent on the concentrations of Yb3+ ions and reaches a maximum at 7%. Logarithmic plots of power dependencies reveal that the green and red emissions originate from a two-photon upconversion process. Based on the photon energy and the emission spectra, the possible upconversion processes and emission mechanisms are discussed. Finally, the optical temperature sensing properties has been performed using the fluorescence intensity ratio technique based on green upconversion emissions. Its temperature sensitivity is found to be above 0.0025 K-1 in the whole temperature range of 300-540 K, revealing this phosphor to be a promising optical temperature sensing material.

  1. Effects of Nd, Sm, Gd, Dy, Er Dopant on Electrical Properties of BaTiO3 Ceramics

    Institute of Scientific and Technical Information of China (English)

    Hao Sue; Wei Yongde; Xing Xiaoxu

    2004-01-01

    BaTiO3 ceramics doped with various quantities of Nd2O3, Sm2O3, Gd2O3, Dy2O3 and Er2O3 were prepared respectively ( the adulterate concentrations were 0. 001,0. 002, 0. 003, 0.005, 0. 007 mol fraction) through a sol-gel method and their electrical properties were researched. It is found that each adulteration of Nd2O3, Sm2O3 Gd2O3,Dy2O3 and Er2O3 all can make the resistivity of BaTiO3 ceramics decline , especially Sm2O3 and Gd2O3. When the addition of Sm2O3 is 0. 001 mol, the resistivity is the smallest, declining from 4.0 × 1012 to 6.5 × 103 Ω different kind of rare earth exhibits different regularity. The grain resistance of BaTiO3 ceramics doped with Sm2O3 or Gd2O3 exhibits a NTC effect, at the same time the grain boundary resistance has a PTC effect, and the grain boundary resistance is much larger than the grain resistance, so the PTC effects of BaTiO3 ceramics doped with Sm2O3 or Gd2O3 originate from the grain boundary. The additions of Nd2O3 , Gd2O3 or Er2O3 make the dielectric constant and the dielectric loss of BaTiO3 ceramics change evidently, especially Nd2O3. The dielectric constant is larger than that of pure BaTiO3 ceramics, on the other hand, the dielectric loss is much lower, which is useful in capacitor fields.

  2. Upconversion photoluminescence of epitaxial Yb{sup 3+}/Er{sup 3+} codoped ferroelectric Pb(Zr,Ti)O{sub 3} films on silicon substrates

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yang, E-mail: zhangy_acd@hotmail.com [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Kämpfe, Thomas [Institut für Angewandte Physik, TU Dresden, 01062 Dresden (Germany); Bai, Gongxun [Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong (China); Mietschke, Michael; Yuan, Feifei; Zopf, Michael [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Abel, Stefan [IBM Research GmbH, Saümerstrasse 4, 8803 Rüschlikon (Switzerland); Eng, Lukas M. [Institut für Angewandte Physik, TU Dresden, 01062 Dresden (Germany); Hühne, Ruben [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Fompeyrine, Jean [IBM Research GmbH, Saümerstrasse 4, 8803 Rüschlikon (Switzerland); Ding, Fei, E-mail: f.ding@ifw-dresden.de [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Schmidt, Oliver G. [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, Reichenhainer strasse 70, 09107 Chemnitz (Germany)

    2016-05-31

    Thin films of Yb{sup 3+}/Er{sup 3+} codoped Pb(Zr,Ti)O{sub 3} (PZT:Yb/Er) have been epitaxially grown on the SrTiO{sub 3} buffered Si wafer by pulsed laser deposition. Strong upconversion photoluminescence was observed in the PZT:Yb/Er thin film. Using piezoresponse force microscopy, polar domains in the PZT:Yb/Er film can be reversibly switched with a phase change of 180°. Ferroelectric hysteresis loop shape with a well-saturated response was observed. The epitaxially grown lanthanide-doped PZT on silicon opens up a promising route to the integration of luminescent functional oxides on the silicon platform. - Highlights: • Epitaxial growth of Yb{sup 3+}/Er{sup 3+} codoped Pb(Zr,Ti)O{sub 3} films on SrTiO{sub 3} buffered silicon • Upconversion emissions were obtained from the lanthanide ion doped thin films. • Saturated ferroelectric hysteresis loops were observed. • Polar domains were switched by PFM with a phase change of 180°.

  3. Preparation and Upconversion Luminescence of Y3Al5O12∶Yb3+, Er3+ Transparent Ceramics

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    YAG:1% (atom fraction) Yb3+, 0.5% (atom fraction) Er3+ transparent ceramics were fabricated by the solid state reaction method using high-purity Y2O3, Al2O3, Yb2O3, and Er2O3 powders as starting materials. The mixed powder compact was sintered at 1760 ℃ for 6 h in vacuum and annealed at 1500 ℃ for 10 h in an air atmosphere. The ceramics consisted of about 10 μm grains and exhibited a pore-free structure. The optical transmittance of the ceramics at 1064 nm was nearly 80%. Upconversion emissions were investigated on the ceramics pumped by a 980 nm continuous wave diode laser, and strong green emission centered at 523 and 559 nm and red emission centered at 669 nm were observed, which originated from the radiative transitions of 2H11/2→4I15/2, 4S3/2→4I15/2, and 4F9/2→4I15/2 of Er3+ ions, respectively.

  4. Upconversion Luminescence Properties of Y2Mo4O15: Yb3+, Er3+ by Solid State Combustion Method.

    Science.gov (United States)

    Jiang, Tao; Xing, Mingming; Fu, Yao; Tian, Ying; Luo, Xixian

    2016-04-01

    The Yb3+ and Er3+ co-doped yttrium molybdenum oxide upconversion phosphors were prepared by the solid state combustion method using urea as fuel at ignition temperature of 550 °C. The upconversion phosphors were characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), and photoluminescence spectra XRD results revealed the samples were pure monoclinic Y2Mo4O15 phases when the sintering temperature was 700 °C. SEM micrographs illustrated particle size distribution was almost uniform with an average particle diameter of about 0.5-1.0 µm. The obtained Y2MO4O15: Yb3+, Er3+ presents bright and pure green upconversion luminescence during daylight pumping under 980 nm LD. According to the analysis of upconversion luminescent mechanism, the cross relaxation processes of Er3+ ions restrained the electron population of red emission energy level, which not only increased the green light upconversion emissions fluorescent branching ratio (IGIR = 153:1) but also enhanced the efficiency and purity of green light emissions.

  5. Optical absorption and fluorescence properties of Er{sup 3+}/Yb{sup 3+} codoped lead bismuth alumina borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Goud, K. Krishna Murthy, E-mail: krishnamurthy.phy@gmail.com; Reddy, M. Chandra Shekhar, E-mail: krishnamurthy.phy@gmail.com; Rao, B. Appa, E-mail: krishnamurthy.phy@gmail.com [Dept. of Physics, Osmania University, Hyderabad-500007, Andhra Pradesh (India)

    2014-04-24

    Lead bismuth alumina borate glasses codoped with Er{sup 3+}/Yb{sup 3+} were prepared by melt quenching technique. Optical absorption, FTIR and photoluminescence spectra of these glasses have been studied. Judd-Ofelt theory has been applied to to the f ↔ f transitions for evaluating Ω{sub 2}, Ω{sub 4} and Ω{sub 6} parameters. Radiative properties like branching ratio β{sub r} and the radiative life time τ{sub R} have been determined on the basis of Judd-Ofelt theory. Upconversion emissions have been observed under 980nm laser excitation at room temperature. Green and red up-conversion emissions are centered at 530, 550 and 656 nm corresponding to {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} transitions of Er{sup 3+} respectively. The results obtained are discussed quantitatively based on the energy transfer between Yb{sup 3+} and Er{sup 3+}.

  6. Y{sub 2}O{sub 3}:Yb/Er nanotubes: Layer-by-layer assembly on carbon-nanotube templates and their upconversion luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Weishi; Shen, Jianfeng; Wan, Lei; Chang, Yu [Department of Materials Science, Fudan University, Shanghai 200433 (China); Ye, Mingxin, E-mail: mxye@fudan.edu.cn [Department of Materials Science, Fudan University, Shanghai 200433 (China); Center of Special Materials and Technology, Fudan University, Shanghai 200433 (China)

    2012-11-15

    Graphical abstract: Well-shaped Y{sub 2}O{sub 3}:Yb/Er nanotubes have been successfully synthesized on a large scale via layer-by-layer assembly on carbon nanotubes templates followed by a subsequent heat treatment process. The as-prepared Y{sub 2}O{sub 3}:Yb/Er nanotubes show a strong red emission corresponding to the {sup 4}F{sub 9/2}–{sup 4}I{sub 15/2} transition of the Er{sup 3+} ions under excitation at 980 nm. Display Omitted Highlights: ► Well-shaped Y{sub 2}O{sub 3}:Yb/Er nanotubes have been successfully synthesized. ► CNTs were used as templates for Y{sub 2}O{sub 3}:Yb/Er nanotubes. ► LBL assembly and calcination were used for preparation of Y{sub 2}O{sub 3}:Yb/Er nanotubes. ► The as-prepared Y{sub 2}O{sub 3}:Yb/Er nanotubes show a strong red emission. -- Abstract: Well-shaped Y{sub 2}O{sub 3}:Yb/Er nanotubes have been successfully synthesized on a large scale via layer-by-layer (LBL) assembly on carbon nanotubes (CNTs) templates followed by a subsequent heat treatment process. The crystal structure, element analysis, morphology and upconversion luminescence properties were characterized. XRD results demonstrate that the diffraction peaks of the samples calcinated at 800 °C or above can be indexed to the pure cubic phase of Y{sub 2}O{sub 3}. SEM images indicate that a large quantity of uniform and rough nanotubes with diameters of about 30–60 nm can be observed. The as-prepared Y{sub 2}O{sub 3}:Yb/Er nanotubes show a strong red emission corresponding to the {sup 4}F{sub 9/2}–{sup 4}I{sub 15/2} transition of the Er{sup 3+} ions under excitation at 980 nm, which have potential applications in such fields as nanoscale devices, molecular catalysts, nanobiotechnology, photonics and optoelectronics.

  7. Spectrophotometric and pH-Metric Studies of Ce(III, Dy(III, Gd(III,Yb(III and Pr(III Metal Complexes with Rifampicin

    Directory of Open Access Journals (Sweden)

    A. N. Sonar

    2011-01-01

    Full Text Available The metal-ligand and proton-ligand stability constant of Ce(III, Dy(III, Gd(III,Yb(III and Pr(III metals with substituted heterocyclic drug (Rifampicin were determined at various ionic strength by pH metric titration. NaClO4 was used to maintain ionic strength of solution. The results obtained were extrapolated to the zero ionic strength using an equation with one individual parameter. The thermodynamic stability constant of the complexes were also calculated. The formation of complexes has been studied by Job’s method. The results obtained were of stability constants by pH metric method is confirmed by Job’s method.

  8. Frequency stabilization to a molecular line of a diode-pumped Er{endash}Yb laser at 1533-nm wavelength

    Energy Technology Data Exchange (ETDEWEB)

    Taccheo, S.; Longhi, S.; Pallaro, L.; Laporta, P. [Centro di Elettronica Quantistica e Strumentazione Elettronica del Consiglio Nazionale delle Ricerche, Dipartimento di Fisica del Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Svelto, C.; Bava, E. [Dipartimento di Elettronica e Informazione del Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano (Italy)

    1995-12-01

    Two identical diode-pumped bulk Er:Yb:glass lasers, operating at 1533-nm wavelength, have been locked independently to the {ital P}(13) vibrational{endash}rotational line of an acetylene molecule. A long-term frequency stability over a 4-h period of better than 1.5 MHz and a short-term laser linewidth narrower than 50 kHz have been obtained by measurement of the beat note between the two lasers. {copyright} {ital 1995 Optical Society of America.}

  9. Planar waveguides formed in a new chemically stable Er3+/Yb3+ co-doped phosphate glass

    Institute of Scientific and Technical Information of China (English)

    Shilong Zhao; Baoyu Chen; Junjiang Hu; Lili Hu

    2005-01-01

    @@ A new Er3+/Yb3+ co-doped phosphate glass has been prepared, which exhibits good chemical durability and spectral properties. Planar graded index waveguides have been fabricated in the glass by Ag+-Na+ ion exchange in a mixed melt of silver nitrate and potassium nitrate. Ion exchange is carried out by varying the process parameters such as temperature, diffusion time, and molten salt compositions. The diffusion parameters, diffusion coefficients, and activation energy are determined by the guidelines of fabricated waveguides, which are determined by the input prism coupling technique.

  10. Dynamics of the Green and Red Upconversion Emissions in Yb3+-Er3+-Codoped Y2O3 Nanorods

    Directory of Open Access Journals (Sweden)

    O. Meza

    2010-01-01

    Full Text Available Efficient green and red upconversion emission in Y2O3:Yb3+, Er3+ nanorods under 978 nm radiation excitation is achieved. Experimental effective lifetimes, luminescent emissions, and nanorod sizes depend strongly on the solvent ratios used during the synthesis. A microscopic nonradiative energy transfer model is used to approach the dynamics of the green, red, and infrared emissions. The excellent agreement between simulated and experimental decay suggests that the energy transfer mechanisms responsible of the visible emission depend on the solvent ratio.

  11. Amplification Properties of Femtosecond Laser-Written Er3+/Yb3+ Doped Waveguides in a Tellurium-Zinc Glass

    Directory of Open Access Journals (Sweden)

    Massimo Olivero

    2013-01-01

    Full Text Available We report on the fabrication and characterization of active waveguides in a TeO2-ZnO glass sample doped with Er3+/Yb3+ fabricated by direct laser writing with a femtosecond laser delivering 150 fs pulses at 1 kHz repetition rate. The waveguides exhibit an internal gain of 0.6 dB/cm at 1535 nm, thus demonstrating the feasibility of active photonics lightwave circuits and lossless components in such a glass composition.

  12. Correlative near-infrared light and cathodoluminescence microscopy using Y2O3:Ln, Yb (Ln = Tm, Er) nanophosphors for multiscale, multicolour bioimaging

    Science.gov (United States)

    Fukushima, S.; Furukawa, T.; Niioka, H.; Ichimiya, M.; Sannomiya, T.; Tanaka, N.; Onoshima, D.; Yukawa, H.; Baba, Y.; Ashida, M.; Miyake, J.; Araki, T.; Hashimoto, M.

    2016-05-01

    This paper presents a new correlative bioimaging technique using Y2O3:Tm, Yb and Y2O3:Er, Yb nanophosphors (NPs) as imaging probes that emit luminescence excited by both near-infrared (NIR) light and an electron beam. Under 980 nm NIR light irradiation, the Y2O3:Tm, Yb and Y2O3:Er, Yb NPs emitted NIR luminescence (NIRL) around 810 nm and 1530 nm, respectively, and cathodoluminescence at 455 nm and 660 nm under excitation of accelerated electrons, respectively. Multimodalities of the NPs were confirmed in correlative NIRL/CL imaging and their locations were visualized at the same observation area in both NIRL and CL images. Using CL microscopy, the NPs were visualized at the single-particle level and with multicolour. Multiscale NIRL/CL bioimaging was demonstrated through in vivo and in vitro NIRL deep-tissue observations, cellular NIRL imaging, and high-spatial resolution CL imaging of the NPs inside cells. The location of a cell sheet transplanted onto the back muscle fascia of a hairy rat was visualized through NIRL imaging of the Y2O3:Er, Yb NPs. Accurate positions of cells through the thickness (1.5 mm) of a tissue phantom were detected by NIRL from the Y2O3:Tm, Yb NPs. Further, locations of the two types of NPs inside cells were observed using CL microscopy.

  13. High efficient 1.56 microm laser operation of Czochralski grown Er:Yb:Sr3Y2(BO3)4 crystal.

    Science.gov (United States)

    Huang, Jianhua; Chen, Yujin; Lin, Yanfu; Gong, Xinghong; Luo, Zundu; Huang, Yidong

    2008-10-27

    An Er:Yb:Sr(3)Y(2)(BO(3))(4) crystal doped with 0.9 at.% Er(3+) and 18.6 at.% Yb(3+) ions was grown by the Czochralski method. End-pumped by diode laser at 970 nm in a hemispherical cavity, 1.3 W quasi-cw laser output around 1.56 microm was achieved in a 1.1-mm-thick Z-cut Er:Yb:Sr(3)Y(2)(BO(3))(4) crystal when the transmission of output coupler is 1.5%. The absorbed pump threshold and slop efficiency of the laser are 4.26 W and 20%, respectively. This crystal has flat and broad gain curve peaked around 1.56 microm, which shows that it is also a potential gain medium for tunable and short pulse lasers.

  14. Effect of biaxial strain induced by piezoelectric PMN-PT on the upconversion photoluminescence of BaTiO₃:Yb/Er thin films.

    Science.gov (United States)

    Wu, Zhenping; Zhang, Yang; Bai, Gongxun; Tang, Weihua; Gao, Ju; Hao, Jianhua

    2014-11-17

    Thin films of Yb3+/Er3+ co-doped BaTiO3 (BTO:Yb/Er) have been epitaxially grown on piezoelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrates. Biaxial strain can be effectively controlled by applying electric field on PMN-PT substrate. A reversible, in situ and dynamic modification of upconversion photoluminescence in BTO:Yb/Er film was observed via converse piezoelectric effect. Detailed analysis and in situ X-ray diffraction indicate that such modulations are possibly due to the change in the lattice deformation of the thin films. This result suggests an alternative method to rationally tune the upconversion emissions via strain engineering.

  15. Large dielectric permittivity in the paraelectric RMn2O5 with R=Tb, Dy, and Er

    Science.gov (United States)

    Han, T. C.; Lin, J. G.; Kuo, K. M.; Chern, G.

    2008-04-01

    The complex dielectric permittivities (ɛ',ɛ″) of RMn2O5 (R =Tb, Dy, and Er) are measured in the temperature range of 78-328 K with frequencies ranging from 100 Hz to 1 MHz. A large real part of the dielectric constant ɛ' (40-140) is observed at room temperature in all three samples studied. These values are higher than the peak value found at the ferroelectric transition of RMn2O5 single crystals. Our results reveal that high dielectric permittivities are related to thermally activated dipolar motions with activation energies of ˜300 meV and a relaxation frequency of ˜3×1012 Hz. The possible relation between the high dielectric permittivity and the size effect of R ions based on the spin-phonon interaction is suggested.

  16. Magnetic structures of Er{sub 6}Mn{sub 23} and Dy{sub 6}Mn{sub 23}

    Energy Technology Data Exchange (ETDEWEB)

    Ouladdiaf, B. [Institut Max von Laue - Paul Langevin, 38 - Grenoble (France); Deportes, J. [Laboratoire de Magnetisme L. Neel, C.N.R.S., BP 166, 38042 Grenoble Cedex 9 (France); Rodriguez-Carvajal, J. [Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)]|[Laboratoire Leon Brillouin (CEA-CNRS), Centre d`Etudes de Saclay, Gif sur Yvette (France)

    1995-08-01

    The R{sub 6}Mn{sub 23} (R=rare earth) compounds crystallize in the cubic Th{sub 6}Mn{sub 23}-type structure with space group Fm3m. Powder neutron-diffraction experiments were performed on Dy{sub 6}Mn{sub 23} and Er{sub 6}Mn{sub 23}. The magnetic unit cell coincides with the chemical one. The R moments have a ferromagnetic non-collinear arrangement, whereas the Mn moments are parallel to the [1 1 1] direction. The magnetic structures belong to the three-dimensional {Gamma}{sub 5g} irreducible representation of Fm3m associated with the wave vector K=[0 0 0]. The spin configurations in both compounds result from the competition between the R-R, R-Mn magnetic interactions and the crystal electric field on the R ions. (orig.).

  17. Multifunctional BaYbF5: Gd/Er upconversion nanoparticles for in vivo tri-modal upconversion optical, X-ray computed tomography and magnetic resonance imaging.

    Science.gov (United States)

    Li, Xiaolong; Yi, Zhigao; Xue, Zhenluan; Zeng, Songjun; Liu, Hongrong

    2017-06-01

    Development of high-quality upconversion nanoparticles (UCNPs) with combination of the merits of multiple molecular imaging techniques, such as, upconversion luminescence (UCL) imaging, X-ray computed tomography (CT), and magnetic resonance (MR) imaging, could significantly improve the accuracy of biological diagnosis. In this work, multifunctional BaYbF5: Gd/Er (50:2mol%) UCNPs were synthesized via a solvothermal method using oleic acid (OA) as surface ligands (denoted as OA-UCNPs). The OA-UCNPs were further treated by diluted HCl to form ligand-free UCNPs (LF-UCNPs) for later bioimaging applications. The cytotoxicity assay in HeLa cells shows low cell toxicity of these LF-UCNPs. Owing to the efficient UCL of BaYbF5: Gd/Er, the LF-UCNPs were successfully used as luminescent bioprobe in UCL bioimaging. And, X-ray CT imaging reveals that BaYbF5: Gd/Er UCNPs can act as potential contrast agents for detection of the liver and spleen in the live mice owing to the high-Z elements (e.g., Ba, Yb, and Gd) in host matrix. Moreover, with the addition of Gd, the as-designed UCNPs exhibit additional positive contrast enhancement in T1-weighted MR imaging. These findings demonstrate that BaYbF5: Gd/Er UCNPs are potential candidates for tri-modal imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Novel Chemically Stable Er3+-Yb3+ Codopded Phosphate Glass for Ion-Exchanged Active Waveguide Devices

    Institute of Scientific and Technical Information of China (English)

    陈宝玉; 赵士龙; 胡丽丽

    2003-01-01

    A novel Er3+-Yb3+ codoped phosphate glass,which combines good chemical durability with good spectroscopic properties,is developed for the ion-exchange process.The relevant properties of this glass are presented for reference in the design and modelling of ion-exchanged active waveguide devices.The weight-loss rate of this glass is 1.45 × 10-5 g.cm-2.h-1 in boiling water,which is comparable to that of Kigre's Q-246 silicate glass.The emission cross section of Er3+ in this glass is calculated to be 0.72 × 10-20 cm2 using the McCumber theory.It is found that a planar waveguide with three modes at 632.8 nm is readily realized in this glass from our primary ion-exchange experiments.

  19. Surfactant effect on the upconversion emission and decay time of ZrO{sub 2}:Yb-Er nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Solis, D. [Centro de Investigaciones en Optica, A.P. 1-948, Leon, Gto. 37160 (Mexico); Lopez-Luke, T. [Centro de Investigaciones en Optica, A.P. 1-948, Leon, Gto. 37160 (Mexico); IIM, UMSNH, C.U., Morelia, Mich. 58060 (Mexico); De la Rosa, E. [Centro de Investigaciones en Optica, A.P. 1-948, Leon, Gto. 37160 (Mexico)], E-mail: elder@cio.mx; Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro, Qro. 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Cd. Mexico, D.F. 07730 (Mexico)

    2009-05-15

    Luminescent properties of doped ZrO{sub 2}:Er{sup 3+} and codoped ZrO{sub 2}:Yb{sup 3+}-Er{sup 3+} nanocrystals with average size {approx}54 nm were analyzed as a function of non-ionic surfactant (Pluronic F-127) concentration. Surfactant and non-surfactant samples were prepared by the sol-gel micelle process with hydrothermal aging and annealed at 1000 deg. C for 5 h. The introduction of the surfactant reduces the presence of impurities such as OH and CO{sub 2} on both samples, and increments the tetragonal phase for codoped nanocrystals. It induces an increment larger than 90% and 70% for doped and codoped, respectively, for an optimum molar ratio of 0.0082. The observed enlargement of fluorescence decay time is partly the result of the nanosize effect but is dominated by the reduction of impurities attached on the nanocrystalline surface.

  20. Semiconductor plasmon induced upconversion enhancement in mCu2-xS@SiO2@Y2O3:Yb(3+),Er(3+) core-shell nanocomposites.

    Science.gov (United States)

    Zhou, Donglei; Li, Dongyu; Zhou, Xiangyu; Xu, Wen; Chen, Xu; Liu, Dali; Zhu, Yongsheng; Song, Hongwei

    2017-09-18

    The ability to modulate the intensity of electromagnetic field by semiconductor plasmon nanoparticles is becoming attractive owing to its unique doping induced local surface plasmon resonance (LSPR) effect different from metals. Herein, we synthesized the mCu2-xS@SiO2@Y2O3:Yb(3+),Er(3+) core-shell composites and experimentally and theoretically studied the semiconductor plasmon induced upconversion (UC) enhancement, and obtained 30 folds UC enhancement compared to that of SiO2@Y2O3:Yb(3+),Er(3+) composites. The UC enhancement was induced by the synthetic effect: amplification of excitation field and the increase of resonance energy transfer (ET) rate from Yb(3+) ions to Er(3+) ions. The experimental results were analyzed in the light of FDTD calculations confirming the effect of amplification of excitation field. In addition, UCL spectra, UC enhancement and dynamics dependent on concentration (Yb(3+)/Er(3+) ions) were investigated and found that the resonance energy transfer (ET) rate from Yb(3+) ions to Er(3+) ions increased ~25% in the effect of LSPR waves. Finally, power dependence of fingerprint identification was successfully performed based on the mCu2-xS@SiO2@Y2O3:Yb(3+),Er(3+) core-shell composites, the color of which can change from green to orange with excitation power increasing. Our work opens up a new concept to design and fabricate the upconversion core-shell structure based on semiconductor plasmon nanoparticles (NPs) and provides applications for upconversion nanocrystals (UCNPs) and semiconductor plasmon NPs in photonics.

  1. Fabrication of a novel nanocomposite Ag/graphene@SiO2-NaLuF4:Yb,Gd,Er for large enhancement upconversion luminescence.

    Science.gov (United States)

    Yin, Dongguang; Cao, Xianzhang; Zhang, Lu; Tang, Jingxiu; Huang, Wenfeng; Han, Yanlin; Wu, Minghong

    2015-06-28

    Upconversion nanocrystals have a lot of advantages over other fluorescent materials. However, their applications are still limited due to their comparatively low upconversion luminescence (UCL). In the present study, a novel nanocomposite of Ag/graphene@SiO2-NaLuF4:Yb,Gd,Er for enhancing UCL was fabricated successfully, and its morphology, crystalline phase, composition, and fluorescent property were investigated. It is interesting to find that the Ag/graphene@SiO2-NaLuF4:Yb,Gd,Er and Ag@SiO2-NaLuF4:Yb,Gd,Er nanocomposites showed high UCL enhancements of 52- and 10-fold compared to the control of Ag-free nanocomposite SiO2-NaLuF4:Yb,Gd,Er, respectively. The enhancement of 52-fold is greater than those reported in our previous studies and some papers. Moreover, the measured life times of the Ag-presented nanocrystals were longer than that of Ag-absent counterparts. These enhancements of UCL can be ascribed to the effect of metal-enhanced fluorescence, which is caused by the enhancement of the local electric field. The UCL intensity of Ag/graphene@SiO2-NaLuF4:Yb,Gd,Er was 5.2-fold higher than that of Ag@SiO2-NaLuF4:Yb,Gd,Er, indicating that graphene presented in the fabricated nanocomposite structure favors metal-enhanced UCL. The small-sized Ag nanoparticles anchored on the graphene sheet mutually enhanced each other's polarizability and surface plasmon resonance, resulting in a big metal-enhanced UCL. This study provides a new strategy for effectively enhancing the UCL of upconversion nanocrystals. The enhancement potentially increases the overall upconversion nanocrystal detectability for highly sensitive biological, medical, and optical detections.

  2. Effect of rare-earth (Er and Gd) substitution on the magnetic and multiferroic properties of DyFe0.5Cr0.5O3

    Science.gov (United States)

    Sharma, Mohit K.; Basu, Tathamay; Mukherjee, K.; Sampathkumaran, E. V.

    2016-10-01

    We report the results of our investigations on the influence of partial substitution of Er and Gd for Dy on the magnetic and magnetoelectric properties of DyFe0.5Cr0.5O3, which is known to be a multiferroic system. Magnetic susceptibility and heat capacity data, apart from confirming the occurrence of magnetic transitions at ~121 and 13 K in DyFe0.5Cr0.5O3, bring out that the lower transition temperature only is suppressed by rare-earth substitution. Multiferroic behavior is found to persist in Dy0.4Ln0.6Fe0.5Cr0.5O3 (Ln  =  Er and Gd). There is an evidence for magnetoelectric coupling in all these materials with qualitative differences in its behavior as the temperature is changed across these two transitions. Remnant electric polarization is observed for all the compounds. The most notable observation is that electric polarization is seen to get enhanced as a result of rare-earth substitution with respect to that in DyFe0.5Cr0.5O3. Interestingly, a similar trend is seen in the magnetocaloric effect, consistent with the existence of magnetoelectric coupling. The results thus provide evidence for the tuning of magnetoelectric coupling by rare-earth substitution in this family of oxides.

  3. Luminescence and vibrational characteristics of the submicro crystals of lanthanum orthophosphates and metaphosphates codoped with Er{sup 3+} and Yb{sup 3+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Jungowska-Hornowska, W. [Department of Inorganic Chemistry, Faculty of Engineering and Economics, Wroclaw University of Economics, 118/120 Komandorska str., 53-345 Wroclaw (Poland); Macalik, L., E-mail: L.Macalik@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland); Lisiecki, R. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland); Godlewska, P. [Department of Bioorganic Chemistry, Faculty of Engineering and Economics, Wroclaw, University of Economics, 118/120 Komandorska str., 53-345 Wroclaw (Poland); Matraszek, A.; Szczygiel, I. [Department of Inorganic Chemistry, Faculty of Engineering and Economics, Wroclaw University of Economics, 118/120 Komandorska str., 53-345 Wroclaw (Poland); Hanuza, J. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland); Department of Bioorganic Chemistry, Faculty of Engineering and Economics, Wroclaw, University of Economics, 118/120 Komandorska str., 53-345 Wroclaw (Poland)

    2009-09-15

    Er{sup 3+} and Yb{sup 3+} doped K{sub 3}La(PO{sub 4}){sub 2} ortho- and KLa(PO{sub 3}){sub 4} metaphosphates were synthesised by the solid state reaction method. The obtained powders were characterised by XRD method, IR and Raman spectroscopy as well as optical absorption spectroscopy. The emission spectra were measured and fluorescence decay studies were carried out at room temperature. The energy transfer from Yb{sup 3+} to Er{sup 3+} and two-photon up-conversion processes were observed and discussed. The influence of the ortho- and metaphosphate host on efficiency of the luminescence was discussed.

  4. A new method of discriminating different types of post-Archean ophiolitic basalts and their tectonic significance using Th-Nb and Ce-Dy-Yb systematics

    Institute of Scientific and Technical Information of China (English)

    Emilio Saccani

    2015-01-01

    -derived components (nascent forearc sub-settings) characterized by MTBs and depleted-MORBs. Two additional discrimination diagrams are proposed: (1) a Dy-Yb diagram is used for discriminating boninite and IAT basalts; (2) a Ce/Yb-Dy/Yb diagram is used for discriminating G-MORBs and normal MORBs. The proposed method may effec-tively assist in recovering the tectonic affinity of ancient ophiolites, which is fundamental for establishing the geodynamic evolution of ancient oceanic and continental domains, as well as orogenic belts.

  5. A new method of discriminating different types of post-Archean ophiolitic basalts and their tectonic significance using Th-Nb and Ce-Dy-Yb systematics

    Directory of Open Access Journals (Sweden)

    Emilio Saccani

    2015-07-01

    -derived components (nascent forearc sub-settings characterized by MTBs and depleted-MORBs. Two additional discrimination diagrams are proposed: (1 a Dy-Yb diagram is used for discriminating boninite and IAT basalts; (2 a Ce/Yb-Dy/Yb diagram is used for discriminating G-MORBs and normal MORBs. The proposed method may effectively assist in recovering the tectonic affinity of ancient ophiolites, which is fundamental for establishing the geodynamic evolution of ancient oceanic and continental domains, as well as orogenic belts.

  6. Template-free synthesis and luminescent properties of hollow Ln:YOF (Ln = Eu or Er + Yb) microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Castro, E. [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, Isla de La Cartuja, 41092 Sevilla (Spain); García-Sevillano, J.; Cussó, F. [Dpto. Física de Materiales, C-04, Universidad Autónoma de Madrid, Avda. Francisco Tomás y Valiente, 7, 28049 Madrid (Spain); Ocaña, M., E-mail: mjurado@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, Isla de La Cartuja, 41092 Sevilla (Spain)

    2015-01-15

    Highlights: • Hollow lanthanide doped YOF spheres have been synthesised through a template-free procedure. • Strong red emissions are observed for Eu-doped spheres under UV illumination. • Concentration quenching of luminescence takes place in the spheres at very high Eu doping levels. • Bright red emission is observed for Er, Yb codoped spheres, making this matrix advantageous for biomedical imaging. - Abstract: A method for the synthesis of hollow lanthanide doped yttrium oxyfluoride (YOF) spheres in the micrometer size range with cubic structure based on the pyrolysis at 600 °C of liquid aerosols generated from aqueous solutions containing the corresponding rare earth chlorides and trifluoroacetic acid has been developed. This procedure, which has been used for the first time for the synthesis of YFO based materials, is simpler and advantageous when compared with other methods usually employed for the production of hollow spheres since it does not require the use of sacrificial templates. In addition, it is continuous, which is desirable because of practical reasons. The procedure is also suitable for doping the YOF spheres with europium cations resulting in down converting red phosphors when activated with UV light, or for co-doping with both Er{sup 3+} and Yb{sup 3+} giving rise to up-converting phosphors, which emit intense red light under near infrared (NIR) irradiation. Because of their optical properties and hollow architecture, the developed materials may find applications in optoelectronic devices and biotechnology.

  7. Analysis of nanostructure and nanochemistry by ASAXS: Accessing phase composition of oxyfluoride glass ceramics doped with Er3+/Yb3+

    Science.gov (United States)

    Haas, Sylvio; Hoell, Armin; Wurth, Roman; Rüssel, Christian; Boesecke, Peter; Vainio, Ulla

    2010-05-01

    Here, we describe the analysis of the nanostructure and average chemical compositions of each phase present in an oxyfluoride glass ceramic, which is composed of fluoride nanocrystals and an oxide glass matrix. The overall composition of the oxyfluoride glass ceramic as prepared is 21.1%SiO26.5%B2O37.0%Al2O321.0%PbF214.3%CdF211.0%YbF30.5%ErF311.0%PbO7.6%CdO(mole%) . Nanocrystals begin to grow at temperatures above the glass transformation temperature at 678 K as observed by x-ray diffraction. We report results from anomalous small-angle x-ray scattering taken at energies of x-ray absorption edges of Er, Yb, Pb, and Cd. By nonlinear regression of the scattering curves obtained from different edges simultaneously, the nanocrystals were found to be describable as polydisperse spheroids. The length of the smaller axis was found to be 6.4±1.4nm while the larger axis was found to be 17.7±3.9nm . By analyzing the scattering contrast as a function of the x-ray energy we found cadmium only in the glass matrix.

  8. Study on relaxation oscillation of Er~(3+)/Yb~(3+) co-doped phosphate glass optical waveguide laser

    Institute of Scientific and Technical Information of China (English)

    LIU HuaDong; ZHANG XiaoXia; WU XianLi; ZHANG Qin; LIU YongZhi

    2009-01-01

    Based on the principle and fabrication of the optical waveguide laser, and through the configuration of the energy level of Er~(3+)/Yb~(3+) co-doped system, the time-dependent rate equations are formed and then solved by Runge-Kutta algorithm. The dynamic characteristic of the waveguide laser pumped unidirec-tionally by 980 nm LD is analyzed. The curves of the relaxation oscillation are drawn, showing that the photon number and inverted population vary alternately. The attenuation characteristic of the peak power is studied. It is gained that time constant changes with pump power, length of waveguide and the reflectivity of output mirror. Furthermore, the impact of the above three parameters on the frequency and end-time of relaxation oscillation is discussed. The frequency of relaxation oscillation is propor-tional to the pump power. Under high reflectivity conditions, the length of waveguide has a weak impact on the frequency. The end-time decreases as the three parameters increase. These features and results provide a theoretical basis for designing the Er~(3+)/Yb~(3+) co-doped phosphate optical waveguide laser.

  9. Infrared-to-green upconversion properties of Er3+/Yb3+ co-doped TeO2-TiO2-K2O glasses upon excitation with 976 nm lasers diode

    Institute of Scientific and Technical Information of China (English)

    SU Fang-ning; DENG Zai-de

    2006-01-01

    The energy transfer and upconversion of Er3+/Yb3+ co-doped TeO2-TiO2-K2O glasses upon excitation with 976 nm lasers diode were studied. The tellurite glasses were prepared by conventional melting methods. Their optical properties and sensitization upconversion spectra were performed. The dependence of green upconversion luminescence intensity on the mole ratio of Yb3+ to Er3+ and Er3+ concentration were discussed in detail. When the mole ratio of Yb3+ to Er3+ is 25/1 and Er3+ concentration is 0.1% (mole fraction), or when the mole ratio of Yb3+ to Er3+ is 10/1 and Er3+ concentration is 0.15%, the optimal upconversion luminescence intensity is obtained. The obtained glasses can be one of the potential candidates for lasers-diode pumping microchip solid-state lasers.

  10. Raman and optical absorption spectroscopic investigation of Yb-Er codoped phosphate glasses containing SiO2

    Institute of Scientific and Technical Information of China (English)

    Youkuo Chen; Lei Wen; Lili Hu; Wei Chen; Y. Guyot; G. Boulon

    2009-01-01

    Yb-Er codoped Na2O-Al2O3-P2Os-xSiO2 glasses containing 0 鈥? 20 mol% SiO2 were prepared successfully. The addition of SiO2 to the phosphate glass not only lengthens the bond between P5+ and non-bridging oxygen but also reduces the number of P=O bond. In contrast with silicate glass in which there is only four-fold coordinated Si4+, most probably there coexist [SiO4] tetrahedron and [SiO6] octahedron in our glasses. Within the range of 0 鈥? 20 mol% SiO2 addition, the stimulated emission cross-section of Er3+ ion only decreases no more than 10%. The Judd-Ofelt intensity parameters of Er3+, 惟.2 does not change greatly, but 惟74 and 惟6 decrease obviously with increasing SiO2 addition, because the bond between Er + and O2- is more strongly covalently bonded.

  11. The Upconversion ″Characteristic Saturation Phenomenon″ of ErYb:ZBLAN Glass Excited by 966 nm Diode Laser%966 nm半导体激光激发下ErYb:ZBLAN玻璃的上转换特征饱和现象C

    Institute of Scientific and Technical Information of China (English)

    陈晓波; 李美仙; 郝昭; 孟广政; 宋增福

    2001-01-01

    本文研究了单掺Er和ErYb共掺的ZBLAN玻璃的上转换发光现象,发现了一种新颖的“Er(0.3)Yb(0.5):ZBLAN样品上转换发光强度随激光功率变化的双对数曲线的斜率相对于Er(0.3):ZBLAN样品有明显的降低、但都保持着很好的直线”的这种“特征”饱和现象,它的上转换机制是一种新颖的“扩散-传递”机制:即Yb3+-Yb3+间能量扩散和随后的Yb3+-Er3+间能量传递。其“特征”饱和现象就是由“Yb3+-Yb3+”间能量扩散导致的。

  12. The 1.53 μm spectroscopic properties of Er3+/Ce3+/Yb3+ tri-doped tellurite glasses containing silver nanoparticles

    Science.gov (United States)

    Huang, Bo; Zhou, Yaxun; Yang, Fengjing; Wu, Libo; Qi, Yawei; Li, Jun

    2016-01-01

    The metallic silver nanoparticles (NPs) was introduced into the Er3+/Ce3+/Yb3+ tri-doped tellurite glasses with composition TeO2-ZnO-La2O3 to improve the 1.53 μm band fluorescence. The UV/Vis/NIR absorption spectra, 1.53 μm band fluorescence spectra, fluorescence lifetimes, X-ray diffraction (XRD) curves, differential scanning calorimeter (DSC) curves and transmission electron microscopy (TEM) image of tri-doped tellurite glasses were measured, together with the Judd-Ofelt intensity parameters, emission cross-sections, absorption cross-sections and radiative quantum efficiencies were calculated to investigate the effects of silver NPs on the 1.53 μm band spectroscopic properties of Er3+ ions, structural nature and thermal stability of glass hosts. It is shown that Er3+/Ce3+/Yb3+ tri-doped tellurite glasses can emit intense 1.53 μm band fluorescence through the combined energy transfer (ET) processes from Yb3+ to Er3+ ions and Er3+ to Ce3+ ions under the 980 nm excitation. At the same time, the introduction of an appropriate amount of silver NPs can further improve the 1.53 μm band fluorescence owing to the enhanced local electric field effect induced by localized surface Plasmon resonance (LSPR) of silver NPs and the possible energy transfer from silver NPs to Er3+ ions, and an improvement by about 120% of fluorescence intensity is found in the studied Er3+/Ce3+/Yb3+ tri-doped tellurite glass containing 0.5 mol% amount of silver NPs with average diameter of ∼15 nm. The energy transfer mechanisms from Yb3+ to Er3+ ions and Er3+ to Ce3+ ions were also quantitatively investigated by calculating energy transfer microparameters and phonon contribution ratios. Furthermore, the thermal stability of glass host increases slightly with the introduction of silver NPs while the glass structure maintains the amorphous nature. The results indicate that the prepared Er3+/Ce3+/Yb3+ tri-doped tellurite glass with an appropriate amount of silver NPs is an excellent gain

  13. Fabrication of and drug delivery by an upconversion emission nanocomposite with monodisperse LaF3:Yb,Er core / mesoporous silica shell structure

    NARCIS (Netherlands)

    Yang, Y.; Qu, Y.; Zhao, J.; Zeng, Q.; Ran, Y.; Zhang, Q.; Kong, X.; Zhang, H.

    2010-01-01

    Monodisperse, uniform, encapsulated mesoporous silicananocomposites with a LaF3:Yb,Er core and a mesoporous silica shell structure, which still exhibit green upconversion photoluminescence (PL) under 980 nm irradiation, have been successfully synthesized and investigated as potential drug delivery s

  14. An upconversion NaYF4:Yb3+,Er3+/TiO2 core-shell nanoparticle photoelectrode for improved efficiencies of dye-sensitized solar cells

    Science.gov (United States)

    Zhang, Jun; Shen, Haiou; Guo, Wei; Wang, Shunhao; Zhu, Chuntao; Xue, Fang; Hou, Jinfeng; Su, Haiquan; Yuan, Zhuobin

    2013-03-01

    Novel upconversion NaYF4:Yb3+,Er3+/TiO2 core-shell nanoparticles (NPs) are synthesized and used to prepare the photoelectrode (PE) of dye-sensitized solar cells (DSSCs). The morphology, structure, photoluminescence characterization of the NaYF4:Yb3+,Er3+/TiO2 core-shell NPs and the photoelectric performance, alternating current impedance spectroscopy of DSSCs are characterized using transmission electron microscopy, X-ray diffraction, upconversion luminescence (UCL) spectrofluorimetry and electrochemistry. Compared with the pure TiO2 PE or the NaYF4:Yb3+,Er3+ upconversion NPs and TiO2 simply mixed prepared PE as the volume ratio of the core-shell structure, the DSSCs with the upconversion core-shell PE show a greater photovoltaic efficiency. The energy conversion efficiency of the DSSCs with a NaYF4:Yb3+,Er3+/TiO2 PE is 23.1% higher than with a pure TiO2 PE and 99.1% higher than with a mixed PE using the same conditions. This enhancement is due to the UCL core extending the spectral response range of DSSCs to the infrared region and their particular shell structure, retaining its semiconductor character. This method represents a novel approach to increase the efficiencies of DSSCs.

  15. Enhanced near-infrared response of a Si:H solar cells with β-NaYF4:Yb3+(18%), Er3+(2%) upconversion phosphors

    NARCIS (Netherlands)

    de Wild, J.|info:eu-repo/dai/nl/314641378; Meijerink, A.|info:eu-repo/dai/nl/075044986; Rath, J.K.|info:eu-repo/dai/nl/304830585; van Sark, W.G.J.H.M.|info:eu-repo/dai/nl/074628526; Schropp, R.E.I.|info:eu-repo/dai/nl/072502584

    2010-01-01

    A near-infrared to visible upconversion phosphor (β-NaYF4:Yb3+ (18%), Er3+ (2%)) has been applied at the back of a thin film hydrogenated amorphous silicon (a-Si:H) solar cell in combination with a white back reflector to investigate its response to sub-bandgap infrared irradiation. Current–voltage

  16. Up-conversion of Er3+/Yb3+co-doped transparent glass-ceramics containing Ba2LaF7 nanocrystals

    Institute of Scientific and Technical Information of China (English)

    胡金民; 周大成; 王荣飞; 陈明厚; 焦清; 余雪; 邱建备

    2013-01-01

    The up-conversion of Er3+/Yb3+co-doped transparent glass-ceramics 50SiO2-10AlF3-5TiO2-30BaF2-4LaF3-0.5ErF3-0.5YbF3 containing Ba2LaF7 nanocrystals under the changing of heat treatment temperature and time were investigated. The Ba2LaF7 nanocrystals precipitated from the glass matrix was confirmed by X-ray diffraction (XRD). The structural investigation carried out by XRD and trans-mission electron microscopy (TEM) evidenced the formation of cubic Ba2LaF7 nanocrystals with crystal size of about 14 nm. Comparing with the samples before heat treatment, the high efficiency up-conversion emission of Er3+/Yb3+co-doped samples was observed in the glass-ceramics under 980 nm laser diode excitation. The increase in red emission intensity bands was stronger than the green bands when the crystal size increased. The mechanism for the up-conversion process in the glass-ceramics and the reasons for the increase of Er3+/Yb3+co-doped up-conversion intensity after heat treatment were discussed.

  17. The risk assessment of Gd2O3:Yb3+/Er3+ nanocomposites as dual-modal nanoprobes for magnetic and fluorescence imaging

    Science.gov (United States)

    Huang, Long; Tian, Xiumei; Liu, Jun; Zheng, Cunjing; Xie, Fukang; Li, Li

    2017-02-01

    Our group has synthesized Gd2O3:Yb3+/Er3+ nanocomposites as magnetic/fluorescence imaging successfully in the previous study, which exhibit good uniformity and monodispersibility with a mean size of 7.4 nm. However, their systematic risk assessment remains unknown. In this article, the in vitro biocompatibility of the Gd2O3:Yb3+/Er3+ was assessed on the basis of cell viability and apoptosis. In vivo immunotoxicity was evaluated by monitoring the product of reactive oxygen species (ROS), clusters of differentiation (CD) markers, and superoxide dismutase (SOD) in Balb/c mice. No significant differences were found in cell viability, apoptosis, and immunotoxicity between our Gd2O3:Yb3+/Er3+ and gadodiamide which are used commonly in clinical. Few nanoprobes were localized in the phagosomes of the liver, heart, lung, spleen, kidney, brain, and tumor under the transmission electron microscopy (TEM) images. In addition, our products reveal good T1-weighted contrast enhancement of xenografted murine tumor. Therefore, the above results may contribute to the effective application of Gd2O3:Yb3+/Er3+ as molecular imaging contrast agents and dual-modal nanoprobes for cancer detection.

  18. Tuning the morphology, luminescence and magnetic properties of hexagonal-phase NaGdF4: Yb, Er nanocrystals via altering the addition sequence of the precursors

    Science.gov (United States)

    Zhao, Shuwen; Xia, Donglin; Zhao, Ruimin; Zhu, Hao; Zhu, Yiru; Xiong, Yuda; Wang, Youfa

    2017-01-01

    Hexagonal-phase NaGdF4: Yb, Er upconversion nanocrystals (UCNCs) with tunable morphology and properties were successfully prepared via a thermal decomposition method. The influences of the adding sequence of the precursors on the morphology, chemical composition, luminescence and magnetic properties were investigated by transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectrometry (ICP-AES), upconversion (UC) spectroscopy, and a vibrating sample magnetometer (VSM). It was found that the resulting nanocrystals, with different sizes ranging from 24 to 224 nm, are in the shape of spheres, hexagonal plates and flakes; moreover, the composition percentage of Yb3+-Er3+ and Gd3+ ions was found to vary in a regular pattern with the adding sequence. Furthermore, the intensity ratios of emission colors (f g/r, f g/p), and the magnetic mass susceptibility of hexagonal-phase NaGdF4: Yb, Er nanocrystals change along with the composition of the nanocrystals. A positive correlation between the susceptibility and f g/r of NaGdF4: Yb, Er was proposed. The decomposition processes of the precursors were investigated by a thermogravimetric (TG) analyzer. The result indicated that the decomposition of the resolved lanthanide trifluoroacetate is greatly different from lanthanide trifluoroacetate powder. It is of tremendous help to recognize the decomposition process of the precursors and to understand the related reaction mechanism.

  19. Enhanced photovoltaic performance of dye-sensitized solar cells based on NaYF4:Yb(3+), Er(3+)-incorporated nanocrystalline TiO2 electrodes.

    Science.gov (United States)

    Zhu, Guang; Wang, Hongyan; Zhang, Quanxin; Zhang, Li

    2015-08-01

    Near infrared to visible up-conversion of light by rare earth ion-doped phosphors (NaYF4:Yb(3+), Er(3+)) that convert multiple photons of lower energy to higher energy photons offer new possibilities for improved performance of photovoltaic devices. Here, up-conversion phosphor NaYF4:Yb(3+), Er(3+) doped nanocrystalline TiO2 films are designed and used as a electrode for dye-sensitized solar cells, and the photovoltaic performance of DSSCs based on composite electrodes are investigated. The results show the cell with NaYF4:Yb(3+), Er(3+) achieves a power conversion efficiency of 7.65% under one sun illumination (AM 1.5G, 100mWcm(-2)), which is an increase of 14% compared to the cell without NaYF4:Yb(3+), Er(3+) (6.71%). The performance improvement is attributed to the dual effects of enhanced light harvesting from extended light absorption range and increased light scattering, and lower electron transfer resistance.

  20. Controlled synthesis and upconversion luminescence properties of LiYF4:Yb0.2Er0.02 nanoparticles

    Science.gov (United States)

    Zhang, Dan; De, Gejihu; Zi, Lu; Xu, Yueshan; Liu, Songtao

    2016-07-01

    A series of high quality tetragonal LiYF4:Yb0.2Er0.02 nanoparticles were synthesized via thermal decomposition method. The influence of reaction conditions on final products has been investigated in detail. The TEM and XRD data show that the size, shape and crystallization of the samples depend on the reaction time and concentration. The upconversion luminescence (UCL) intensity gradually enhanced along with the sizes of the samples increasing. And when the reaction solvent system is oleic acid/1-octadecence (OA/ODE), the samples show smaller size and stronger emission compared with oleic acid/oleylamine/1-octadecence (OA/OM/ODE). Under 980 nm NIR laser diode excitation, all the samples show intense green emission between 510 and 570 nm wavelength from 4S3/2 → 4I15/2 and 2H11/2 → 4I15/2 transitions of Er3+ and intense red emission between 640 and 690 nm attributed to 2F11/2 → 4I15/2 transition of Er3+, both of the processes belong to two-photon energy absorption.

  1. Er3+/Yb3+共掺Gd3Sc2Ga3O12晶体的上转换发光%Up-conversion luminescence in Er3+/Yb3+-codoped Gd3Sc2Ga3O12 laser crystals

    Institute of Scientific and Technical Information of China (English)

    罗建乔; 孙敦陆; 张庆礼; 刘文鹏; 谷长江; 吴路生; 殷绍唐

    2008-01-01

    研究了提拉法生长的Er3+/Yb3+:Gd3Sc2Ga3O12和Er3+:Gd3Sc2Ga3O12晶体在室温下320-1700 nm范围的吸收光谱和500-750 nm范围内的上转换荧光谱,同时对其上转换荧光的可能发生机制、途径以及上转换过程可能对Er3+的2.8 μm波段激光振荡产生的影响进行了分析和讨论.结果表明:Yb3+的敏化显著地增强了晶体在966 nm附近的吸收能力,大幅度加宽了晶体在该处的吸收带宽.在940 nm激光的激发下,Er3+/Yb3+:Gd3Sc2Ga3O12中的上转换荧光强度明显强于Er3+:Gd3Sc2Ga3O12中的上转换荧光强度,表明Yb3+与Er3+之间存在高效率的能量传递,其主要上转换机制可能为Yb3+-Er3+,Er3+-Er3+能量传递.

  2. Magnetic Ground States of the Rare-Earth Tripod Kagome Lattice Mg2 RE3 Sb3 O14 (RE =Gd ,Dy ,Er )

    Science.gov (United States)

    Dun, Z. L.; Trinh, J.; Li, K.; Lee, M.; Chen, K. W.; Baumbach, R.; Hu, Y. F.; Wang, Y. X.; Choi, E. S.; Shastry, B. S.; Ramirez, A. P.; Zhou, H. D.

    2016-04-01

    We present the structural and magnetic properties of a new compound family, Mg2 RE3 Sb3 O14 (RE =Gd ,Dy ,Er ), with a hitherto unstudied frustrating lattice, the "tripod kagome" structure. Susceptibility (ac, dc) and specific heat exhibit features that are understood within a simple Luttinger-Tisza-type theory. For RE =Gd , we found long-ranged order (LRO) at 1.65 K, which is consistent with a 120° structure, demonstrating the importance of diople interactions for this 2D Heisenberg system. For RE =Dy , LRO at 0.37 K is related to the "kagome spin ice" physics for a 2D system. This result shows that the tripod kagome structure accelerates the transition to LRO predicted for the related pyrochlore systems. For RE =Er , two transitions, at 80 mK and 2.1 K are observed, suggesting the importance of quantum fluctuations for this putative X Y system.

  3. Slow light enhanced near infrared luminescence in CeO{sub 2}: Er{sup 3+}, Yb{sup 3+} inverse opal photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhengwen, E-mail: yangzw@kmust.edu.cn; Wu, Hangjun; Li, Jun; Shao, Bo; Qiu, Jianbei; Song, Zhiguo

    2015-08-25

    Highlights: • CeO{sub 2}: Er{sup 3+}, Yb{sup 3+} photonic crystals was prepared. • Near infrared emission in the CeO{sub 2}: Er{sup 3+}, Yb{sup 3+} inverse opal was obtained. • Near infrared emission was enhanced by slow light effect of photonic crystals. - Abstract: The surface plasmon resonances of metal nanoparticles and energy transfer between rare earth ions were used widely to enhance the near infrared emission of rare earth ions. In this paper, a new method for near infrared emission enhancement of rare-earth is reported. The CeO{sub 2}: Er{sup 3+}, Yb{sup 3+} inverse opals with the photonic band gaps at the 500 and 450 nm were prepared by using polystyrene colloidal crystal as templates, and their near infrared emission properties were investigated. The results show that the near infrared emission property of the CeO{sub 2}: Er{sup 3+}, Yb{sup 3+} inverse opals depends on the overlapped extend between the excited light and photonic band gap. The near infrared emission located at the 1540 nm of the CeO{sub 2}: Er{sup 3+}, Yb{sup 3+} inverse opals have been enhanced obviously when the wavelength of the excitation light overlapped with photonic band gaps edge, which is attributed to the slow light effect of photonic crystals. The enhancement of near infrared emission may be important for the development of infrared laser and amplifiers for optical communication.

  4. Preparation and up-conversion luminescence of SrAlF{sub 5}:Yb{sup 3+}/Er{sup 3+} nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jun [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China); Hua, Ruinian, E-mail: rnhua@dlnu.edu.cn [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Zhang, Wei; Feng, Zhiqing; Tang, Dongxin; Na, Liyan [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Chen, Baojiu, E-mail: chenmbj@sohu.com [Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China)

    2014-03-05

    Graphical abstract: The SrAlF{sub 5} nanorods co-doped with various Yb{sup 3+}/Er{sup 3+} concentrations was synthetized via a microemulsion-hydrothermal process for the first time. It was found that the optimum doping concentration of Yb{sup 3+} and Er{sup 3+} in SrAlF{sub 5} matrix was about 4 mol%. Furthermore, the temperature effect of upconversion luminescence was investigated. It was also found that the post heat-treatment could greatly improve upconversion luminescence. Highlights: • SrAlF{sub 5}:Yb{sup 3+}/Er{sup 3+} nanorods were synthesized via a microemulsion-hydrothermal process. • Crystal structure and morphology were characterized by using XRD and FESEM. • The upconversion luminescence intensity depend on LD working current was studied. • The post heat-treatment could greatly improve upconversion luminescence. -- Abstract: Yb{sup 3+} and Er{sup 3+} co-doped SrAlF{sub 5} nanorods with average diameter of 35 nm and average length of 400 nm were synthesized via a microemulsion-hydrothermal process, and their crystal structure and morphology were characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. The optimum doping concentration of Yb{sup 3+}/Er{sup 3+} in SrAlF{sub 5} matrix was about 4 mol%. The upconversion luminescence intensity dependence on the laser diode (LD) working current was studied and the possible upconversion mechanism was analyzed. Furthermore, the temperature effect of upconversion luminescence was investigated. It was also found that the post heat-treatment could greatly improve upconversion luminescence.

  5. White light luminophores based on Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+}-coactivated strontium fluoride powders

    Energy Technology Data Exchange (ETDEWEB)

    Rozhnova, Yu.A., E-mail: julia.r89@mail.ru [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation); Luginina, A.A., E-mail: annaluginina@mail.ru [All-Russian Institute for Scientific and Technical Information (VINITI), Russian Academy of Sciences, Moscow (Russian Federation); Voronov, V.V., E-mail: voronov@lst.gpi.ru [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Ermakov, R.P., E-mail: x-ray_diffraction@mail.ru [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Kuznetsov, S.V., E-mail: kouznetzovsv@gmail.com [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Ryabova, A.V., E-mail: nastya.ryabova@gmail.com [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Pominova, D.V., E-mail: pominovadv@rambler.ru [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Arbenina, V.V., E-mail: arbenina@mitht.org [M.V. Lomonosov Moscow State University of Fine Chemical Technologies, Moscow (Russian Federation); Osiko, V.V., E-mail: osiko@lst.gpi.ru [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Fedorov, P.P., E-mail: ppfedorov@yandex.ru [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2014-11-14

    We have developed a synthetic protocol for the preparation of SrF{sub 2}-based Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+}-coactivated nano-crystalline white light luminophores by co-precipitation from aqueous solutions and have achieved a good level of sample homogeneity in the course of their preparation. We established that the particle size and morphology of the precipitated nanopowders were essentially independent from the fluorinating reagent used, the starting materials' ratio and the conditions of thermal treatment. We achieved the target white light luminescence for Sr{sub 1−x}(Yb/Er/Tm){sub x}F{sub 2+x} specimens with the best results obtained for the Sr{sub 0.785}Yb{sub 0.200}Er{sub 0.010}Tm{sub 0.005}F{sub 2.215} sample at 400 mW pumping power (λ = 974 nm). - Highlights: • Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+}-coactivated SrF{sub 2} nanopowders precipitated from aqueous solutions. • Particle size and morphology of luminophores are essentially independent on used fluorinating agent. • The best result observed for Sr{sub 0.785}Yb{sub 0.200}Er{sub 0.010}Tm{sub 0.005}F{sub 2.215} (400 mW; 974 nm). • Precipitation of NH{sub 4}F–SrF{sub 2} solid solution has been detected and proved.

  6. Thermo-Optical Tuning of Whispering Gallery Modes in Er:Yb Doped Glass Microspheres to Arbitrary Probe Wavelengths

    CERN Document Server

    Watkins, Amy; Chormaic, Síle Nic

    2012-01-01

    We present experimental results on an all-optical, thermally-assisted technique for broad range tuning of microsphere cavity resonance modes to arbitrary probe wavelengths. An Er:Yb co-doped phosphate glass (Schott IOG-2) microsphere is pumped at 978 nm via the supporting stem and the heat generated by absorption of the pump light expands the cavity and changes the refractive index. This is a robust tuning method that decouples the pump from the probe and allows fine tuning of the microsphere's whispering gallery modes. Pump/probe experiments were performed to demonstrate thermo-optical tuning to specific probe wavelengths, including the 5S1/2 F = 3 to 5P3/2 F' = 4 laser cooling transition of 85Rb. This is of particular interest for cavity QED-type experiments, while the broad tuning range achievable is useful for integrated photonic devices, including sensors and modulators.

  7. Optimized flat supercontinuum generation in high nonlinear fibers pumped by a nanosecond Er/Yb Co-doped fiber amplifier

    Science.gov (United States)

    Ouyang, D. Q.; Guo, C. Y.; Ruan, S. C.; Yan, P. G.; Wei, H. F.; Luo, J.

    2014-04-01

    Flat supercontinuum generation has been demonstrated in high nonlinear fibers with zero dispersion wavelengths at 1480 and 1500 nm, which were pumped by a MOPA structured Er/Yb co-doped fiber amplifier based on a modulated nanosecond seed laser with the wavelength of 1552 nm. The spectra and output powers affected by the zero dispersion wavelengths, fiber lengths and pump pulse widths were investigated experimentally. A flat spectrum with 5 dB bandwidth from 1220 nm to beyond 1700 nm (assuming the pump peak was filtered) in the optical spectrum analyzer detectable range was finally obtained by optimizing the fiber length and pump pulse width. The maximum output power was 1.02 W, including the peaks near 1550 nm.

  8. Gain and Noise Figure of a Double-Pass Waveguide Amplifier Based on Er/Yb-Doped Phosphate Glass

    Institute of Scientific and Technical Information of China (English)

    JIN Guo-Liang; SHAO Gong-Wang; Mu Huan; HU Li-Li; LI Qu

    2005-01-01

    @@ A waveguide amplifier is fabricated by Ag+-Na+ two-step ion exchange on Er/Yb-doped phosphate glass. Thespectroscopic performance of glass and the properties of channel waveguide are characterized. A double-passconfiguration is adopted to measure the gain and noise figure (NF) of the waveguide amplifier, and the comparisonof gain and NF for the single and double-pass configuration of the waveguide amplifier is presented. The resultsshow that the double-pass configuration can make the gain increase from 8.8dB (net gain 2.2dB/cm) of thesingle-pass one to 14.6dB (net gain 3.65dB/cm) for small input power at 1534nm, and the NF are all lower than5.5dB for both the configurations.

  9. K(+)-Na+ ion-exchanged waveguides in Er(3+)-Yb3+ codoped phosphate glasses using field-assisted annealing.

    Science.gov (United States)

    Liu, Ke; Pun, Edwin Y

    2004-05-20

    Buried channel waveguides were fabricated in Er(3+)-Yb3+ codoped phosphate glasses with use of the thermal two-step ion-exhange method. The K(+)-Na+ ion-exchange process was first carried out in pure KNO3 molten bath, and then field-assisted annealing (FAA) was used to make the buried waveguides. The fluorescence properties of bulk glasses and channel waveguides were characterized, and the waveguide properties were studied. The formation mechanism of buried waveguides was analyzed, and the improved gain characteristics of the waveguide amplifiers with use of different FAA temperatures were measured. The maximum net gain of the waveguide amplifiers at 1.534-microns wavelength was measured to be approximately 3.4 +/- 0.1 dB/cm with 120-mW pump power at 975-nm wavelength.

  10. Yb3+ and Er3+ co-doped Y2Ce2O7 nanoparticles: synthesis and spectroscopic properties

    Indian Academy of Sciences (India)

    Honghui Jiang; Weixiong You; Xiaolin Liu; Jinsheng Liao; Ping Wang; Bin Yang

    2013-12-01

    Yb3+ and Er3+ co-doped Y2Ce2O7 nanoparticles sintered at different temperatures were prepared by homogeneous co-precipitation method. The products were characterized by X-ray powder diffraction (XRD), energy-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The results indicated that the particle sizes and morphologies of the samples were heavily influenced by the sintering temperature. As temperature increased, the particle sizes became gradually larger and more agglomerate. The emissions including green and red upconversion emissions were investigated under 980 nm excitation. The emission intensities of the samples also depended on the sintering temperature. Two photon processes were mainly responsible for green and red upconversion emissions.

  11. Laser Characteristics of Cladding-Pumped Short Er3+/yb3+ Codoped Single Mode Phosphate Glass Fibre

    Institute of Scientific and Technical Information of China (English)

    XU Shan-Hui; YANG Zhong-Min; XU Wen-Cheng; QIU Dong-Lai; ZHANG Qin-Yuan; JIANG Zhong-Hong

    2009-01-01

    We experimentally investigate the laser characteristics of a ser/es of short pieces of newly-developed Er3+/Yb3+ codoped single mode phosphate glass fibres via the cladding pump of a 976nm multimode laser diode. A stable continuous-wave single transverse mode laser with over 85 m W at 1553 nm is generated from a 5.5-cm-long active fibre. Single mode laser output power per unit length is up to 15 m W/cm. Moreover, the slope efficiency is 11.8% when the pump power is below 940mW and the 3dB linewidth is 0.06nm at the maximum pump power. The numerical simulation results show that the laser emission slope efficiency can exceed 20% by means of increasing the coupling efficiency of the pump to the fibre core further.

  12. Investigation on luminescence properties of Er3+-Yb3+-Tm3+ co-doped Gd2O3 hollow microspheres

    Science.gov (United States)

    Xu, Fang; Han, Wan-lei; Liu, Xiao-bo; Song, Ying-lin

    2011-06-01

    The Gd2O3 hollow microspheres have been successfully fabricated via carbonaceous polysaccharide microspheres as templates and urea as a precipitating agent, which involved the deposition of an inorganic coating on the surface of carbon microsphere, followed by heat treated 800°C for 4h. The obtained high uniform Gd2O3 microspheres with a spherical shape and hollow structure are uniform in size and distribution. The possible mechanism of evolution from glucose to carbonaceous polysaccharide microspheres and the chemical reaction of each step to form the final hollow spheres are proposed. The rare earth ion Ln3+ doped Gd2O3 (Ln = Er, Yb and Tm) hollow microspheres show bright up-conversion luminescence with different colors coming from different activator ions under ultraviolet or 980 nm light excitation, which may open new possibilities to synthesize other hollow spherical materials and extend their applications.

  13. Arrays of distributed-Bragg-reflector waveguide lasers at 1536 nm in Yb/Er codoped phosphate glass

    Science.gov (United States)

    Veasey, David L.; Funk, David S.; Sanford, Norman A.; Hayden, Joseph S.

    1999-02-01

    We have demonstrated an array of monolithic, single-frequency-distributed-Bragg-reflector (DBR), waveguide lasers operating near 1536 nm wavelengths. The lasers were fabricated by forming waveguides in Yb/Er-codoped phosphate glass by ion exchange. The slope efficiency for each laser as a function of launched pump power is 26% and the thresholds occur at 50 mW of launched pump power. An output power of 80 mW was achieved with 350 mW of coupled pump power. Each laser exhibits stable operation on a single longitudinal mode and all have linewidths less than 500 kHz. A comb of waveguides with varying effective indices allows the selection of wavelength using a single-period grating.

  14. High Power Er/Yb Codoped Double Clad Fiber Pulsed Amplifier Based on an All-Fiber Configuration

    Institute of Scientific and Technical Information of China (English)

    ZHOU Lei; NING Ji-Ping; CHEN Cheng; HAN Qun; ZHANG Wei-Yi; WANG Jun-Tao

    2009-01-01

    We report an all-fiber two-stage high power pulsed amplifier,seeded with a 1550nm,1 kHz repetition rate rectangular pulse,and based on Er/Yb co-doped double clad fiber.All the characteristics are measured in the experiment.The maxima/slope efficiency is 22.56%,which is the highest we know of at such a low repetition rate,and the maximal output signal power is 1W.The various factors that affect the pulsed amplifier performance are analyzed.A high output power while keeping high power conversion efficiency can be obtained with careful selection of the input power,pump power and repetition rate.The experimental results show that the crucial parameters should be optimized when designing all-fiber pulsed amplifiers.

  15. High-Power Er3+/Yb3+ Codoped Double-Cladding Fibre Amplifier with More Than 2 W Output Power

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-Ge; FENG Xin-Huan; LI Li-Jun; LI Yao; YUAN Shu-Zhong; KAI Gui-Yun; LI Yi-Gang; DONG Xiao-Yi

    2005-01-01

    @@ A high-power Er3+/Yb3+-codoped double-cladding all-fibre amplifier was successfully demonstrated and experimentally investigated. The amplifier could be operated with a maximum output power of 2.18 W and 2.11 W at 1541nm and 1550nm wavelengths, respectively, when the maximum pump power was 6.07W. The power conversion efficiency was up to 35.6% and 34.4% at the two wavelengths, respectively. The output power and the gain were greater than 2.00 W and 20.0dB, respectively, in the wavelength range from 1539nm to 1565nm for 20.0mW input signal power. The gain fluctuation and the noise figure around 1550nm wavelength were less than 0.3 dB and 6.0 dB, respectively.

  16. Characterization of conjugates of NaYF4:Yb,Er,Gd upconversion nanoparticle with aluminium phthalocyanines

    Science.gov (United States)

    Watkins, Zane; Uddin, Imran; Britton, Jonathan; Nyokong, Tebello

    2017-02-01

    NaYF4:Er/Yb/Gd upconversion nanoparticles (UCNP) capped with amino groups were covalently attached to chloro aluminium tetrasulphonated phthalocyanine (ClAlTSPc) and chloro aluminium tetracarboxy phthalocyanine (ClAlTCPc). The conjugates were characterized using different techniques such as infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). There was a decrease in the intensity of fluorescence emission spectra of the UCNPs at 658 nm in the presence of the phthalocyanines. This decrease indicates an energy transfer between the donor UCNP and conjugated accepting phthalocyanine (Pc), due to Förster resonance energy transfer (FRET). FRET efficiencies of 18% and 21% for ClAlTSPc and ClAlTCPc, respectively, were obtained. Oxygen generation by ClAlTSPc following FRET was proved.

  17. Down- and up-conversion emissions in Er{sup 3+}–Yb{sup 3+} codoped TeO{sub 2}–ZnO–ZnF{sub 2} glasses

    Energy Technology Data Exchange (ETDEWEB)

    Miguel, A. [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alda. Urquijo s/n, 48013 Bilbao (Spain); Arriandiaga, M.A. [Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU, Apartado 644, Bilbao (Spain); Morea, R. [Instituto de Optica, Consejo Superior de Investigaciones Científicas CSIC, Serrano 121, 28006 Madrid (Spain); Fernandez, J. [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alda. Urquijo s/n, 48013 Bilbao (Spain); Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 San Sebastian (Spain); Gonzalo, J. [Instituto de Optica, Consejo Superior de Investigaciones Científicas CSIC, Serrano 121, 28006 Madrid (Spain); Balda, R., E-mail: wupbacrr@bi.ehu.es [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alda. Urquijo s/n, 48013 Bilbao (Spain); Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 San Sebastian (Spain)

    2015-02-15

    In this work, we report the near infrared and upconversion emissions of Er{sup 3+}–Yb{sup 3+} codoped fluorotellurite TeO{sub 2}–ZnO–ZnF{sub 2} glasses for different YbF{sub 3} concentrations ranging between 0.5 and 2 wt%. The study includes absorption and emission spectra and lifetime measurements for the infrared and visible fluorescence. The energy transfer between Yb{sup 3+} and Er{sup 3+} ions is confirmed by the temporal behavior of the near-infrared luminescence of Yb{sup 3+} ions as well as by the enhancement of the 1532 nm emission of Er{sup 3+} ions in the codoped samples. The Yb{sup 3+}→Er{sup 3+} energy transfer efficiency is calculated from the Yb{sup 3+} lifetimes in single and codoped samples. Back transfer from Er{sup 3+} to Yb{sup 3+} ions is present under near infrared and visible excitation of Er{sup 3+} ions at 798 and 488 nm respectively. An enhancement of the visible upconversion fluorescence is also observed in the codoped samples due to energy transfer from Yb{sup 3+} to Er{sup 3+} ions. The standardized value for the efficiency of the green upconversion emission is 1.06×10{sup −4} for the codoped sample with 2 wt% of YbF{sub 3} which is comparable to that reported in lead–zinc–tellurite glasses. The possible upconversion processes and mechanisms leading to the population of several excited levels are discussed. - Highlights: • The effect of Yb{sup 3+} concentration on the NIR and VIS emissions of Er{sup 3+}ions is studied. • TheYb{sup 3+}↔Er{sup 3+} energy transfer in fluorotellurite glasses is demonstrated. • Increase of the green upconversion emission with Yb{sup 3+} concentration due to Yb{sup 3+}→Er{sup 3+} energy transfer. • The ratio of red to green upconversion emissions depends on the concentration of Yb{sup 3+} ions.

  18. Full potential calculations and atom in molecule analysis of the bonding properties of perovskites Borides XRh3B (X=Dy, Ho, Er)

    OpenAIRE

    Ouahrani T.; Merad Boudia I.; Lasri B.

    2013-01-01

    ab initio calculations were performed for the cubic perovskites Borides XRh3B, (X=Dy, Ho, Er). In this work, we have used the augmented plane-wave plus local orbital method to compute the equilibrium structural parameters and electronic structure of densities of states, as well as for the first time, prediction of the thermo-elastic properties of these crystals are presented. The chemical bonding of these compounds has been investigated by using of topological analyses grounded in the theory ...

  19. Upconversion luminescence of KGd(MoO4)2∶Er3+,yb3+ powder prepared by Pechini method

    Institute of Scientific and Technical Information of China (English)

    CHEN Qijing; QIN Lianjie; FENG Zhiqiang; GE Ru; ZHAO Xiangjin; XU Huizhong

    2011-01-01

    Er3+ doped potassium gadolinium molybdate (KGM) phosphor with sensitizer Yb3+ ion was synthesized by the Pechini method using citric acid and ethylene glycol.The crystallization processes of the phosphor precursors were characterized by X-ray diffraction (XRD) and thermogravimetry-differential scanning calorimetry (TG-DSC),which indicated that ultrafine uniform crystallites of KGM∶Er,Yb were obtained by sintering the precursors at above 650 ℃ for 5 h.Upconversion luminescence (UL) spectra of the samples were studied by a 976 nm semiconductor laser diode (LD) excitation.The UL spectra exhibited the green and red emission bands that were attributed to the 2H11/2,4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+,respectively.The possible UL mechanisms of Er3+ were explained by means of an energy level diagram.The maximum luminescent intensity was achieved when the concentration of Er3+,Yb3+ arriVed at 1 mol.% and 20 mol.%,respectively.

  20. Tunable Upconversion Luminescence and Energy Transfer Process in BaLa2ZnO5:Er3+/Yb3+ Phosphors

    Directory of Open Access Journals (Sweden)

    Lefu Mei

    2015-01-01

    Full Text Available BaLa2ZnO5:Er3+/Yb3+ has been synthesized via a high temperature solid-state method, and the tunable upconversion luminescence and energy transfer process between Yb3+ and Er3+ in this system have been demonstrated. Upon 980 nm laser excitation, the intense green and red emission around 527, 553, and 664 nm were observed for BaLa2ZnO5:Er3+/Yb3+, which can be assigned to the characteristic energy level transitions of 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, and 4F9/2 → 4I15/2 of Er3+, respectively. The critical Er3+ quenching concentration (QC was determined to be about 5 mol%, and the power studies indicated that mixture of 2- and 3-photon process was responsible for the green and red upconversion luminescence.

  1. Strong paramagnetic crystalline LnVO{sub 4} (Ln: Gd, Tb, Dy, Ho, Er) nanoparticles synthesized by a fabricating method

    Energy Technology Data Exchange (ETDEWEB)

    Bulbul, Berna; Beyaz, Seda, E-mail: sedacan@balikesir.edu.tr

    2016-04-15

    Strong paramagnetic lanthanide orthovanadate (LnVO{sub 4}, Ln: Gd, Tb, Dy, Ho, Er) nanoparticles were synthesized under ambient conditions by a novel precipitation method that is economical and fabricating. To the X-ray diffraction patterns, all samples are well-crystallized zircon type orthovanadate and have pure tetragonal phase. Their crystal sizes increased from 12.58 to 15.12 nm with increasing the ionic radii of lanthanide. As confirmed with the surface observation by a transmission electron microscope, it was identified that their two-dimensional projection is an ellipse with the two major axes. It was seen that the sizes of nanoparticles (14.40nm-70.69 nm) were bigger than the crystal sizes because of their polycrystalline structures. Besides, the particle sizes increased with reduction of ionic radii of lanthanide. The magnetic properties obtained from a vibrating sample magnetometer revealed that all nanoparticles are strong paramagnetic at room temperature showing an increase in molar susceptibility up to 4.79 × 10{sup −1} cm{sup 3} mol{sup −1}. Such highly crystalline, small and paramagnetic nanoparticles could be thought to be convenient for biomedical applications. - Highlights: • A general fabricating method for lanthanide orthovanadate nanoparticles is proposed. • The method generates highly small and crystalline nanoparticles. • The reduction in ionic radius of lanthanide (Ln{sup 3+}) causes to increase particle size.

  2. Synthesis and characterization of Yb and Er based monosilicate powders and durability of plasma sprayed Yb{sub 2}SiO{sub 5} coatings on C/C-SiC composites

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Zuhair S.; Zou Binglin; Huang Wenzhi; Fan Xizhi; Gu Lijian; Chen Xiaolong; Zeng Shuibing; Wang Chunjie [State Key Laboratory of Rare Earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin (China); Cao Xueqiang, E-mail: xcao@ciac.jl.cn [State Key Laboratory of Rare Earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin (China)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Ultra-pure rare-earth monosilicate powders based on Er and Yb have been fabricated by solid-state reaction. Black-Right-Pointing-Pointer Spray-drying treatment results in powders with free flowing characteristics and rounded surface morphologies. Black-Right-Pointing-Pointer CTEs are found to be 7.1 ppm/ Degree-Sign C for Yb{sub 2}SiO{sub 5} and 7.5 ppm/ Degree-Sign C for Er{sub 2}SiO{sub 5}. Black-Right-Pointing-Pointer Plasma spraying has been used to deposit Yb{sub 2}SiO{sub 5} coatings on C/C-SiC substrate. Black-Right-Pointing-Pointer Coatings remain strongly intact with the substrate on thermal cycling between {approx}400 Degree-Sign C and 1500 Degree-Sign C in gas burner rig experiment. - Abstract: Rare-earth silicates such as Yb{sub 2}SiO{sub 5} and Er{sub 2}SiO{sub 5} are promising environmental barrier coating materials for ceramic matrix composites. In this work, Yb{sub 2}SiO{sub 5} and Er{sub 2}SiO{sub 5} ceramic powders have been synthesized by solid-state reaction using Yb{sub 2}O{sub 3}, Er{sub 2}O{sub 3} and SiO{sub 2} as starting materials. The fabricated powders were subjected to spray drying treatment for subsequent synthesis of coatings by plasma spraying. The spray drying resulted in well-dispersed and spherical powder particles with good flowability. Analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry and differential scanning calorimetry (TGA/DSC) and dilatometry were applied to study the microstructural and thermal characteristics of the powders. Ultra-high purity monosilicate powders formed as a result of heating treatments at 1400 Degree-Sign C in a box furnace for 20 h. TG/DSC revealed the genesis temperatures of the silicate formation (low temperature polymorphs) and also showed that the solid-state reactions to form Yb and Er based monosilicates proceeded without any weight-loss in the tested temperature range. The values of coefficients of

  3. Synthesis and spectroscopy of color tunable Y{sub 2}O{sub 2}S:Yb{sup 3+},Er{sup 3+} phosphors with intense emission

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, G.A., E-mail: akgsh@yahoo.com [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249-0697 (United States); Pokhrel, M. [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249-0697 (United States); Martinez, A. [Centro de Investigaciones en Optica A.C., Leon, Gto., 37150 Mexico (Mexico); Dennis, R.C. [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249-0697 (United States); Villegas, I.L. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A.C., Leon, Gto., 37150 Mexico (Mexico); Sardar, D.K. [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249-0697 (United States)

    2012-02-05

    Highlights: Black-Right-Pointing-Pointer Brightest upconversion phosphor composition based on YbEr doped Y{sub 2}O{sub 2}S explored. Black-Right-Pointing-Pointer Emission cross sections obtained are 4-8 times larger than single crystal and amorphous material. Black-Right-Pointing-Pointer Internal quantum yield of nearly 62% was obtained for the green emission. Black-Right-Pointing-Pointer All the three oxysulfide phosphor compositions show color tunable upconversion. - Abstract: Trivalent ytterbium and erbium doped in yttrium oxysulfide (Y{sub 2}O{sub 2}S:Yb{sup 3+},Er{sup 3+}) phosphors were synthesized by solid state flux fusion method and their upconversion spectral properties were studied as a function of different Yb{sup 3+} concentrations. The solid state flux fusion results in well crystallized hexagonal shaped phosphor particles with an average size of 3.8 {mu}m. The detailed optical characterizations such as absorption, emission, and fluorescence decay were performed to explore the emission processes in the UV-VIS-NIR as well as to quantitatively estimate the fluorescence quantum yield. Upconversion spectral studies show that for all the compositions, green emissions are stronger; in particular the green emission intensity is 1.7 times stronger than the red intensity with composition of 9 mol% Yb{sup 3+} and 1 mol% Er{sup 3+}. Mechanisms of upconversion by two-photon and energy transfer processes are interpreted and explained. The color coordinates are measured and the color tunability was analyzed as a function of the 980 nm excitation power. Results show that the Y{sub 2}O{sub 2}S:Yb{sup 3+},Er{sup 3+} phosphor offers power dependent color tuning properties where the emission color can be tuned from 490 to 550 nm by simply changing the 980 nm excitation power from 10 to 50 mW.

  4. NIR luminescence studies on Er{sup 3+}:Yb{sup 3+} co-doped sodium telluroborate glasses for lasers and optical amplifer applications

    Energy Technology Data Exchange (ETDEWEB)

    Annapoorani, K.; Marimuthu, K., E-mail: mari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural Institute - Deemed University, Gandhigram – 624 302 (India); Murthy, N. Suriya [Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam–603 102 (India)

    2016-05-23

    Er{sup 3+}:Yb{sup 3+} co-doped Sodium telluroborate glasses were prepared with the chemical composition (49.5–x)B{sub 2}O{sub 3}+25TeO{sub 2}+5Li{sub 2}CO{sub 3}+10ZnO+10NaF+0.5Er{sub 2}O{sub 3}+xYb{sub 2}O{sub 3} (where x= 0.1, 0.5, 1.0 and 2.0 in mol %) following the melt quenching technique. With the addition of Yb{sup 3+} ions into Er{sup 3+} ions in the prepared glasses, the absorption cross-section values were found to increase due to the effective energy transfer from {sup 2}F{sub 5/2} level of Yb{sup 3+} ions to the {sup 4}I{sub 11/2} level of Er{sup 3+} ions. The fluorescence around 1550 nm correspond to the {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition was observed under 980 nm pumping. Among the present glasses, integrated intensity was found to be higher for 1.0 mol% Yb{sup 3+} ion glass. The parameters such as stimulated emission cross- section, Gain bandwidth and quantum efficiency of the {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition was found to be higher for the NTBE1.0Y glass and the same is suggested for potential NIR lasers and optical amplifier applications.

  5. Comparative study of spectroscopic properties of Er3+/yb3+-codoped tellurite glass and fibres under 980nm excitation

    Institute of Scientific and Technical Information of China (English)

    Dai Shi-Xun; Zhang Jun-Jie; Li Shun-Guang; Xu Shi-Qing; Wang Guo-Nian; Yang Jian-Hu; Hu Li-Li

    2004-01-01

    A tellurite fibre of TeO2-ZnO-La2Os-Li2O glass codoped with 20000 ppm ytterbium and 5000 ppm erbium was fabricated by the suction casting and rod-in-tube technologies. The absorption spectrum of Er3+/Yb3+ -codoped bulk glass has been measured. From the Judd-Ofelt intensity parameters, the spontaneous emission probability and radiative lifetime τrad of Er3+:4I13/2 →4I15/2 transition for the bulk glass have been calculated. The emission fluorescence spectra and lifetimes around 1.5μm, and subsequent upconversion fluorescence in the range of 500-700nm were measured in fibres and compared with those in bulk glass. The changes in amplified spontaneous emission with fibre length and pumping power was also measured. It was found that the emission spectrum from erbium in fibres is almost twice as broad as the corresponding spectrum in bulk glass when pumped at 980nm.

  6. In-vitro and in-vivo imaging of prostate tumor using NaYF4: Yb, Er up-converting nanoparticles.

    Science.gov (United States)

    Yu, Yongjiang; Huang, Tao; Wu, Yu; Ma, Xiaorong; Yu, Guopeng; Qi, Jun

    2014-04-01

    The aim of this study was to investigate the feasibility of prostate tumor bioimaging both in vitro and in vivo using an upconversion fluorophore, NaYF4: Yb, Er nanoparticles. Luminescent signals of human prostate cancer cells (CWR22R and LNCaP) labeled with NaYF4: Yb, Er nanoparticles were detected by laser scanning confocal microscope, while Cy3 or FITC was used as control probe. Mouse-human prostate cancer model was developed by subcutaneously injecting the CWR22R cells into BALB/c nude mice to investigate the in-vivo imaging properties of NaYF4:Yb, Er nanoparticles. Both CWR22R and LNCaP cells could phagocytose NaYF4:Yb, Er nanoparticles in vitro, and the cellular uptake of CWR22R cells was much higher than that of LNCaP cells (95.42 ± 3.47 % vs. 51.63 ± 6.43 %), which made us choose the former for the further study. CWR22R cells pre-labeled with NaYF4:Yb, Er nanoparticles showed no obvious decrease of fluorescence intensity (P > 0.05) after light exposure, while the fluorescence intensity of Cy3 or FITC labeled cells decreased rapidly with prolonged bleaching (P nanoparticles formed tumors 4 weeks after injection, and the tumor length-diameter of the nanoparticle group and the control group was (10.3 ± 2.0) mm and (9.8 ± 2.5) mm, respectively. Significant upconversion fluorescence signals were observed in the tumors of the nanoparticle group when being excited at 980 nm by a NIR laser. In summary, the results suggest that as an intensive fluorescence imaging label agent, NaYF4:Yb, Er nanoparticles possess unique features and can be used for imaging prostate tumor cells both in vitro and in vivo by phagocytosis.

  7. A fruitful demonstration in sensors based on upconversion luminescence of Yb3+/Er3+codoped Sb2O3-WO3-Li2O (SWL) glass-ceramic

    Science.gov (United States)

    Prasad Sukul, Prasenjit; Kumar, Kaushal

    2016-07-01

    In this article, erbium and ytterbium doped lithium tungsten antimonate (Yb3+/Er3+:Sb2O3-WO3-Li2O) glass-ceramics (GC) is synthesized and its novel applications in temperature sensing and detection of latent fingerprints is studied. It is also estimated that this material could be useful as a solar cell concentrator. The upconversion emission studies on Yb3+/Er3+:SWL glass-ceramics have shown intense green emission at 525 nm (2H11/2 → 4I15/2) & 545 nm (4s3/2 → 4I15/2). The variation of UC intensities with external temperature have shown a well-fashioned pattern, which suggests that the 2H11/2 and 4S3/2 levels of Er3+ ion are thermally coupled and can act as a temperature sensor in the 300-500 K temperature range. Dry powder of Yb3+/Er3+:SWL glass-ceramic is used to develop latent fingerprint with high contrast in green color on glass slide.

  8. Spectroscopic properties and mechanism of Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals

    Science.gov (United States)

    Hu, Yue-Bo; Qiu, Jian-Bei; Zhou, Da-Cheng; Song, Zhi-Guo; Yang, Zheng-Wen; Wang, Rong-Fei; Jiao, Qing; Zhou, Da-Li

    2014-02-01

    Transparent Tm3+/Er3+/Yb3+ co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals are prepared. Under excitation of a 980-nm laser diode (LD), compared with the glass before heat treatment, the Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics can emit intense blue, green and red up-conversion luminescence and Stark-split peaks; X-ray diffraction (XRD) and transmission electron microscope (TEM) results show that BaF2 nanocrystals with an average diameter of 20 nm are precipitated from the glass matrix. Stark splitting of the up-conversion luminescence peaks in the glass ceramics indicates that Tm3+, Er3+ and (or) Yb3+ ions are incorporated into the BaF2 nanocrystals. The up-conversion luminescence intensities of Tm3+, Er3+ and the splitting degree of luminescence peaks in the glass ceramics increase significantly with the increase of heat treat temperature and heat treat time extension. In addition, the possible energy transfer process between rare earth ions and the up-conversion luminescence mechanism are also proposed.

  9. Emission properties of hydrothermal Yb{sup 3+}, Er{sup 3+} and Yb{sup 3+}, Tm{sup 3+}-codoped Lu{sub 2}O{sub 3} nanorods: upconversion, cathodoluminescence and assessment of waveguide behavior

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, Elixir William; Pujol, MarIa Cinta; DIaz, Francesc [Fisica i Cristal.lografia de Materials, Universitat Rovira i Virgili, Campus Sescelades c/ Marcel.lI Domingo s/n, E-43007 Tarragona (Spain); Choi, Soo Bong; Rotermund, Fabian [Division of Energy Systems Research, Ajou University, 443-749 Suwon (Korea, Republic of); Park, Kyung Ho [Korea Advanced Nano Fab Center, 443-270 Suwon (Korea, Republic of); Jeong, Mun Seok [Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, 500-712 Gwangju (Korea, Republic of); Cascales, Concepcion, E-mail: ccascales@icmm.csic.es [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones CientIficas, c/Sor Juana Ines de la Cruz, 3 Cantoblanco, E-28049 Madrid (Spain)

    2011-02-18

    Yb{sup 3+} and Ln{sup 3+} (Ln{sup 3+} = Er{sup 3+} or Tm{sup 3+}) codoped Lu{sub 2}O{sub 3} nanorods with cubic Ia3-bar symmetry have been prepared by low temperature hydrothermal procedures, and their luminescence properties and waveguide behavior analyzed by means of scanning near-field optical microscopy (SNOM). Room temperature upconversion (UC) under excitation at 980 nm and cathodoluminescence (CL) spectra were studied as a function of the Yb{sup +} concentration in the prepared nanorods. UC spectra revealed the strong development of Er{sup 3+4}F{sub 9/2} {yields} 4I{sub 15/2} (red) and Tm{sup 3+1}G{sub 4} {yields} {sup 3}H{sub 6} (blue) bands, which became the pre-eminent and even unique emissions for corresponding nanorods with the higher Yb{sup 3+} concentration. Favored by the presence of large phonons in current nanorods, UC mechanisms that privilege the population of {sup 4}F{sub 9/2} and {sup 1}G{sub 4} emitting levels through phonon-assisted energy transfer and non-radiative relaxations account for these observed UC luminescence features. CL spectra show much more moderate development of the intensity ratio between the Er{sup 3+4}F{sub 9/2} {yields}{sup 4}I{sub 15/2} (red) and {sup 2}H{sub 11/2}, {sup 4}S{sub 3/2} {yields} {sup 4}I{sub 15/2} (green) emissions with the increase in the Yb{sup 3+} content, while for Yb{sup 3+}, Tm{sup 3+}-codoped Lu{sub 2}O{sub 3} nanorods the dominant CL emission is Tm{sup 3+1}D{sub 2} {yields} {sup 3}F{sub 4} (deep-blue). Uniform light emission along Yb{sup 3+}, Er{sup 3+}-codoped Lu{sub 2}O{sub 3} rods has been observed by using SNOM photoluminescence images; however, the rods seem to be too thin for propagation of light.

  10. Up-conversion luminescence in Yb(3+)-Er(3+)/Tm(3+) co-doped Al2O3-TiO2 nano-composites.

    Science.gov (United States)

    Mokoena, Teboho Patrick; Linganiso, Ella Cebisa; Kumar, Vinod; Swart, Hendrik C; Cho, So-Hye; Ntwaeaborwa, Odireleng Martin

    2017-06-15

    The sol gel method was used to prepare rare-earths (Yb(3+)-Er(3+) and Yb(3+)-Tm(3+)) co-doped Al2O3-TiO2 nano-composite powder phosphors and their up-conversion luminescence properties were investigated. Mixed oxides of titania (TiO2) rutile phase and an early stage crystallization of alumina (Al2O3) phase were confirmed from the X-ray diffraction data with the average crystallite size of ∼36nm. The rutile phase TiO2 was further confirmed by selected area diffraction analysis of the composites. Microscopy analysis showed interesting rod-like morphologies with rough surfaces indicating that a spherulitic growth process took place during the crystal growth. Photoluminescence characterization of the phosphors was carried out under near infra-red excitation at 980nm and the prominent emission bands were observed in the visible region at 523, 548 and 658nm for the Yb(3+)-Er(3+) co-doped systems. Emission in bands extending from the visible to near infra-red regions were observed at 480, 650, 693 and 800nm for the Yb(3+)-Tm(3+) co-doped systems. These upconverted emissions and energy transfer mechanisms taking place are discussed in detail.

  11. Flat supercontinuum generation covering C-band to U-band in two-stage Er/Yb co-doped double-clad fiber amplifier

    Science.gov (United States)

    Zhang, B.; Hou, J.; Liu, P. Z.; Jin, A. J.; Jiang, Z. F.

    2011-11-01

    Supercontinuum generation in the gain fiber in two-stage nanosecond pulse Er/Yb co-doped double-clad fiber amplifier had been demonstrated for the first time to our knowledge instead of the conventional method in which nonlinear fiber was pumped by lasers. The Er/Yb co-doped double-clad fiber acts as the gain media and nonlinear media. This route reduces the splice between fiber laser and nonlinear fiber. The supercontinuum was achieved with spectrum range from 1530 nm to beyond 1700 nm at 6 W output power covering the total C-band to U-band. From the analyzing of the spectra at different stages in the amplifiers, it can be found that it is the modulation instability in the anomalous dispersion regime that initiates the supercontinuum gereration.

  12. Clean synthesis of YOF:Er3+, Yb3+ upconversion colloidal nanoparticles in water through liquid phase pulsed laser ablation for imaging applications

    Science.gov (United States)

    Anjana, R.; Kurias, K. M.; Jayaraj, M. K.

    2017-10-01

    Upconversion luminescent nanomaterials have great outlook towards imaging applications. These materials have high chemical and thermal stability, low auto fluorescence, high photo stability and IR excitation does not cause photo damage to living cells and penetrate deeply into tissue. Most of the reported nanoparticles are synthesized through chemical methods in which surface modification is needed for dispersing nanoparticles in water. In this paper we report clean and simple synthesis of upconversion luminescent yttrium oxyfluoride (YOF) nanoparticles through laser ablation in deionized water. YOF:Er3+, Yb3+ pellets were used for ablation. Er3+ is the emission centre Yb3+ is the sensitizer. Obtained colloidal solution is transparent to day light and showing red emission on exciting with 980 nm IR laser. By controlling ablation parameters particles of size less than 10 nm dispersed uniformly in water can be obtained through this surfactant free method. The synthesized nanoparticles can be used for cell imaging.

  13. Visible up-conversion and near-infrared luminescence of Er3+/Yb3+ co-doped SbPO4-GeO2 glasses

    Science.gov (United States)

    Manzani, D.; Montesso, M.; Mathias, C. F.; Krishanaiah, K. Venkata; Ribeiro, S. J. L.; Nalin, M.

    2016-07-01

    Recent advances in glass chemistry have led to new multifunctional optical glasses of great technological importance. Glasses containing high amounts of antimony have been studied for use in nonlinear optics, near-infrared transmission, and as hosts for rare-earth ions in photonic devices. This work describes a luminescence study of Er3+ and Er3+/Yb3+ co-doping in a new SbPO4-GeO2 binary glass system. Near-infrared and visible up-conversion emissions were observed in the green and red regions, which are enhanced when the samples are co-doped with Yb3+. Near-infrared emissions have good quantum efficiency and full width half maximum of 61 nm. Visible up-conversion emissions are governed by two photons and described by excited state absorption, energy transfer and cross-relaxation processes.

  14. [Crystal structure and upconversion emission of Yb3+/Er(3+) -co-doped NaYF4 nanocrystals].

    Science.gov (United States)

    Yao, Li-Li; Luo, Li; Dong, Guo-Shuai; Wang, Yin-Hai

    2013-11-01

    Yb3+/EP(3+) -co-doped cubic NaYF4 and Yb3+/Er3+/Gd(3+) -tri-doped hexagonal NaYF4 nanocrystals were synthesized by a modified coprecipitation method with ethylenediamine tetraacetic acid (EDTA) as chelating agent. The samples' morphology, crystal phase and upconversion emission were measured with transmission electron microscope (TEM), X-ray diffraction patterns (XRD) and upconversion luminescence spectrum. TEM and XRD results showed that the phase transition from cubic to hexagonal was promoted through Gd3+ doping. It has been reported that the upconversion efficiency of hexagonal NaYF4 is higher than that of cubic NaYF4, however, the effect of crystal phase on upconversion luminescence has not been well understood. This work focuses analysis of measurement results to compare the effect of, crystal phase on the crystal field energy splitting and upconversion emission intensity as well as emission color, and a mechanism of luminescence enhancement and color tunability are revealed. Strong visible upconversion luminescence can be seen clearly by the naked eyes in both cubic phase and hexagonal phase samples upon excitation by a 980 nm laser diode with power of 10 mW, consisting of green emissions centered at around 525/550 nm originating from the transitions of 2H11/2/4 S3/2 --> 4 I15/2 and red emission at about 657 nm from 4F9/2 to 4 I15/2 of Er3+ ions respectively. In comparison to cubic sample, the hexagonal phase sample presented much stronger and sharper upconversion luminescence, whose emission efficiency was enhanced 10 times with an additional transition of 2 H9/2 --> 4I13/2 at 557 nm, furthermore, the intensity ratio of red to green emission increased from 2 :1 to 3 : 1. Doping NaYF4 nanocrystals with Gd3+ ions induced the hexagonal-to-cubic phase transition and thus decreased the crystal symmetry, consequently increased absorption cross-section and 4f-4f transition probabilities by relaxing forbidden selection rules, resulting in stronger emission. In the

  15. Low-temperature synthesis, luminescence and phonon properties of Er and/or Dy doped LaAlO{sub 3} nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Maczka, MirosLaw, E-mail: m.maczka@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 WrocLaw 2 (Poland); Mendoza-Mendoza, Esmeralda; Fuentes, Antonio F. [Cinvestav Unidad Saltillo, Apartado Postal 663, Saltillo, 25000 Coahuila (Mexico); Lemanski, Karol; Deren, PrzemysLaw [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 WrocLaw 2 (Poland)

    2012-03-15

    LaAlO{sub 3}, La{sub 0.9}Dy{sub 0.1}AlO{sub 3}, La{sub 0.9}Er{sub 0.1}AlO{sub 3} and La{sub 0.8}Dy{sub 0.1}Er{sub 0.1}AlO{sub 3} nanocrystalline powders were synthesized in a two-step process by combining a mechanically induced metathesis reaction and molten salt synthesis. The proposed two-step methodology easily allows obtaining pure and/or doped perovskite-type LaAlO{sub 3} nanopowders at remarkably low temperatures, i.e., already at 350 Degree-Sign C although firing at 500 Degree-Sign C is needed in order to get pure phases. The obtained samples were characterized by XRD, TEM, Raman, IR and luminescence methods. These methods showed that the mean crystallite size is near 50-60 nm and the LaAlO{sub 3} nanocrystallites have R3{sup Macron }c structure, the same as bulk LaAlO{sub 3}. Raman spectrum of nanocrystalline LaAlO{sub 3} is very similar to that of bulk. In contrast to this behavior, IR spectra of the synthesized compounds are significantly different from the IR spectrum of bulk LaAlO{sub 3}. Origin of this behavior is discussed. Luminescence study showed that the cross-relaxation processes quench emission intensity of the samples doped with Dy{sup 3+} and Er{sup 3+}. - Graphical abstract: TEM image of La{sub 0.9}Er{sub 0.1}AlO{sub 3} (left panel) and histogram showing the particle size distribution (right panel). Highlights: Black-Right-Pointing-Pointer Pure and Er or Dy doped LaAlO3 samples were synthesized at remarkably low temperatures. Black-Right-Pointing-Pointer The mean crystallite size of the obtained samples is 40-60 nm. Black-Right-Pointing-Pointer Nanocrystallites have R3{sup Macron }c structure, the same as bulk LaAlO3. Black-Right-Pointing-Pointer IR spectra are significantly different from the IR spectrum of bulk. Black-Right-Pointing-Pointer We discuss origin of this behavior.

  16. Design of LD Pumped Er~(3+):Yb~(3+) Codoped All-solid-state Laser%LD泵浦Er^3+:Yb^3+共掺全固态激光器设计

    Institute of Scientific and Technical Information of China (English)

    徐翠莲; 王斌科; 王雯洁

    2012-01-01

    By using the method of matrix optics,the formula was deduced for computing the beamwidth and image distance of the Gauss beam after focusing by coupling system.Considering the thermal-lens effect,numerical simulations were performed on the active plano-concave cavity.Finally,according to the conditions of laser resonator,the coating program for the output mirror and filterwas confirmed.%对LD泵浦Er3+:Yb3+共掺全固态激光器进行了整体设计,利用矩阵光学方法推导了高斯光束经耦合系统聚焦后束腰宽度和像距的计算公式。考虑激光棒的热透镜效应,对有源平平腔、平凹腔进行了数值计算,分析了谐振腔的稳定性。最后,根据激光谐振条件,确定了激光输出镜及滤光片的镀膜方案,为最终获得高效率、稳定的激光输出提供了理论依据。

  17. Influence of surface coating on structural, morphological and optical properties of upconversion-luminescent LaF3:Yb/Er nanoparticles

    Science.gov (United States)

    Ansari, Anees A.; Yadav, Ranvijay; Rai, S. B.

    2016-07-01

    LaF3:Yb/Er (core), LaF3:Yb/Er@LaF3 (core/shell) and LaF3:Yb/Er@LaF3@SiO2 (core/shell/SiO2) nanoparticles were synthesized using citric-acid-based complexation process. X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray analysis, optical absorption, band-gap energy ( E g), Fourier transform infrared and upconversion emission spectroscopy were employed to investigate the structural, morphological and optical properties of the synthesized core and core/shell/SiO2 nanoparticles. These core/shell/SiO2 nanoparticles can be well dispersed in aqueous solvents to form clear colloidal solution. The optical band-gap energy was decreased after shell formation due to increase in the crystalline size. The growth of an inactive and porous silica layers simultaneously on the surface of luminescent core-nanoparticles resulting an increase in average crystalline size of the nanoparticles. As-prepared inert shell-coated core/shell nanoparticles show intensive upconversion-luminescence as compared to the seed-core and silica-surface-modified core/shell/SiO2 nanoparticles because luminescent ions (Yb3+ and Er3+) ions located at the particle surface were protected from the non-radiative decay arising from surface dangling bonds and capping agent. However, our study revealed that there was only a slight reduction in upconversion efficiency for the silica-modified core/shell nanoparticles, indicating that upconversion properties of the upconversion nanoparticles are largely preserved in the core/shell/SiO2 nanoparticles. Absorption and upconversion-luminescence properties were examined for future application in the development of optical devices as well as optical bioprobes.

  18. Experimental evidence and theoretical modeling of two-photon absorption dynamics in the reduction of intensity noise of solid-state Er:Yb lasers.

    Science.gov (United States)

    El Amili, Abdelkrim; Kervella, Gaël; Alouini, Mehdi

    2013-04-01

    A theoretical and experimental investigation of the intensity noise reduction induced by two-photon absorption in a Er,Yb:Glass laser is reported. The time response of the two-photon absorption mechanism is shown to play an important role on the behavior of the intensity noise spectrum of the laser. A model including an additional rate equation for the two-photon-absorption losses is developed and allows the experimental observations to be predicted.

  19. Photosensitivity of the Er/Yb-Codoped Schott IOG1 Phosphate Glass Using 248 nm, Femtosecond, and Picosecond Laser Radiation

    OpenAIRE

    Pissadakis, Stavros; Michelakaki, Irini

    2008-01-01

    The effect of 248 nm laser radiation, with pulse duration of 5 picoseconds, 500 femtoseconds, and 120 femtoseconds, on the optical properties and the Knoop hardness of a commercial Er/Yb-codoped phosphate glass is presented here. Refractive index changes of the order of few parts of 10-4 are correlated with optical absorption centers induced in the glass volume, using Kramers-Kroning relationship. Accordingly, substantially lower refractive index changes are measured in volume Bragg gratings ...

  20. Passively Q-switched Er,Yb:GdAl3(BO3)4 laser with single-walled carbon nanotube based saturable absorber

    Science.gov (United States)

    Gorbachenya, K. N.; Kisel, V. E.; Yasukevich, A. S.; Prudnikova, M. B.; Maltsev, V. V.; Leonyuk, N. I.; Choi, S. Y.; Rotermund, F.; Kuleshov, N. V.

    2017-03-01

    We demonstrate a passively Q-switched Er,Yb:GdAl3(BO3)4 diode-pumped laser emitting near 1.5 µm. By using a single-walled carbon nanotube (SWCNT) as a saturable absorber, Q-switched laser pulses with energy of 0.8 µJ and duration of 130 ns at a maximum repetition rate of 500 kHz were obtained at 1550 nm.

  1. Role of ytterbium-erbium co-doped gadolinium molybdate (Gd2(MoO4)3:Yb/Er) nanophosphors in solar cells.

    Science.gov (United States)

    Jin, Xiao; Li, Haiyang; Li, Dongyu; Zhang, Qin; Li, Feng; Sun, Weifu; Chen, Zihan; Li, Qinghua

    2016-09-05

    Insufficient harvest of solar light energy is one of the obstacles for current photovoltaic devices to achieve high performance. Especially, conventional organic/inorganic hybrid solar cells (HSCs) based on PTB7 as p-type semiconductor can only utilize 400-800 nm solar spectrum. One effective strategy to overcome this obstacle is the introduction of up-conversion nanophosphors (NPs), in the virtue of utilizing the near infrared region (NIR) of solar radiation. Up-conversion can convert low-energy photons to high-energy ones through multi-photon processes, by which the solar spectrum is tailored to well match the absorptive domain of the absorber. Herein we incorporate erbium-ytterbium co-doped gadolinium molybdate (Gd2(MoO4)3, GMO), denoted as GMO:Yb/Er, into TiO2 acceptor film in HSCs to enhance the light harvest. Here Er3+ acts as activator while Yb-MoO4 2- is the joint sensitizer. Facts proved that the GMO:Yb/Er single crystal NPs are capable of turning NIR photons to visible photons that can be easily captured by PTB7. Studies on time-resolved photoluminescence demonstrate that electron transfer rate at the interface increases sharply from 0.65 to 1.42 × 109 s-1. As a result, the photoelectric conversion efficiency of the GMO:Yb/Er doped TiO2/PTB7 HSCs reach 3.67%, which is increased by around 25% compared to their neat PTB7/TiO2 counterparts (2.94%). This work may open a hopeful way to take the advantage of those conversional rare-earth ion doped oxides that function in tailoring solar light spectrum for optoelectronic applications.

  2. 220 fs Er-Yb:glass laser mode-locked by a broadband low-loss Si/Ge saturable absorber

    CERN Document Server

    Grawert, F J; Ilday, F O; Liu, J; Gopinath, J T; Shen, H M; Wada, K; Ippen, E P; Kimerling, L C; Kaertner, Franz X

    2004-01-01

    We demonstrate femtosecond performance of an ultra-broadband high-index-contrast saturable Bragg reflector consisting of a silicon/silicon-dioxide/germanium structure that is fully compatible with CMOS processing. This device offers a reflectivity bandwidth of over 700 nm and sub-picosecond recovery time of the saturable loss. It is used to achieve mode-locking of an Er-Yb:glass laser centered at 1540 nm, generating 220 fs pulses, with the broadest output spectrum to date.

  3. Quadratic general rotary unitized design for doping concentrations and up-conversion luminescence properties of Er{sup 3+}/Yb{sup 3+} co-doped NaLa(MoO{sub 4}){sub 2} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jiashi, E-mail: sunjs@dlmu.edu.cn; Shi, Linlin; Li, Shuwei; Li, Jingjing; Li, Xiangping, E-mail: lixp@dlmu.edu.cn; Zhang, Jinsu; Cheng, Lihong; Chen, Baojiu

    2016-08-15

    Highlights: • NaLa(MoO4)2: Er3+/Yb3+ phosphor is synthesized by solid state method. • QGRUD is first applied to the codoping concentration option. • Optimized phosphor presents more stable UC emissions than the commercial phosphor. - Abstract: It is still a great challenge that designing proper codoping concentrations of rare earth ions for achieving intensest expected emission from the studied phosphor. In this work, the quadratic general rotary unitized design (QGRUD) was introduced into the codoping concentration option of NaLa(MoO{sub 4}){sub 2}: Er{sup 3+}/Yb{sup 3+} phosphor for upconversion (UC) applications, and the optimum doping concentrations of Er{sup 3+} and Yb{sup 3+} for achieving maximum UC luminescence intensity, which is close to commercial NaYF{sub 4}:Er{sup 3+}/Yb{sup 3+} phosphor, were obtained. The two-photon process was assigned to the green UC emissions in the optimized NaLa(MoO{sub 4}){sub 2}: Er{sup 3+}/Yb{sup 3+} phosphor. It was also demonstrated that the optimized phosphor presented more stable upconversion emissions than the commercial NaYF{sub 4}:Er{sup 3+}/Yb{sup 3+} phosphor.

  4. On observation of the downconversion mechanism in Er{sup 3+}/Yb{sup 3+} co-doped tellurite glass using thermal and optical parameters

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, M.S.; Santos, F.A. [Universidade Federal da Grande Dourados, Faculdade de Ciências Exatas e Tecnologias, Dourados, MS (Brazil); Yukimitu, K.; Moraes, J.C.S. [Universidade Estadual Paulista, UNESP, Departamento de Física e Química, Av. Brasil, 56, 15385-000 Ilha Solteira, SP (Brazil); Nunes, L.A.O. [Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970 São Carlos, SP (Brazil); Andrade, L.H.C. [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul, Cidade Universitária de Dourados, CP 351, Dourados, MS (Brazil); Lima, S.M., E-mail: smlima@uems.br [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul, Cidade Universitária de Dourados, CP 351, Dourados, MS (Brazil)

    2015-01-15

    In this work we report the observed downconversion (DC) mechanism in Er{sup 3+}/Yb{sup 3+}-codoped tellurite glasses (in mol%, 80TeO{sub 2}–10Li{sub 2}O–10TiO{sub 2}). The samples were synthesized by the conventional melt-quenching method and then studied using optical spectroscopy and thermal lens spectroscopy (TLS). These characterizations enabled investigation of the radiative and nonradiative processes involved in energy transfer from erbium to ytterbium. The visible Er{sup 3+} fluorescence intensities decreased as a function of the Yb{sup 3+} concentration, and there was a corresponding increase in the ytterbium emission at around 980 nm. Simultaneously, there was a reduction in the heat-generated due nonradiative decays (∼21%) when ytterbium was added. This temperature change was measured by TLS measurements and the results corroborate with the indicated by spectroscopic interpretation. - Highlights: • Energy transfer from erbium to ytterbium in tellurite glass. • ∼56% of cross-relaxation efficiency from Er{sup 3+} to Yb{sup 3+}. • Downconversion effect in tellurite glasses. • Downconversion effect observation by thermal lens spectroscopy.

  5. The Upconversion Luminescence of Er3+/Yb3+/Nd3+ Triply-Doped β-NaYF4 Nanocrystals under 808-nm Excitation

    Science.gov (United States)

    Tian, Lijiao; Xu, Zheng; Zhao, Suling; Cui, Yue; Liang, Zhiqin; Zhang, Junjie; Xu, Xurong

    2014-01-01

    In this paper, Nd3+–Yb3+–Er3+-doped β-NaYF4 nanocrystals with different Nd3+ concentrations are synthesized, and the luminescence properties of the upconversion nanoparticles (UCNPs) have been studied under 808-nm excitation for sensitive biological applications. The upconversion luminescence spectra of NaYF4 nanoparticles with different dopants under 808-nm excitation proves that the Nd3+ ion can absorb the photons effectively, and the Yb3+ ion can play the role of an energy-transfer bridging ion between the Nd3+ ion and Er3+ ion. To investigate the effect of the Nd3+ ion, the decay curves of the 4S3/2 → 4I15/2 transition at 540 nm are measured and analyzed. The NaYF4: 20% Yb3+, 2% Er3+, 0.5% Nd3+ nanocrystals have the highest emission intensity among all samples under 808-nm excitation. The UC (upconversion) mechanism under 808-nm excitation is discussed in terms of the experimental results. PMID:28788246

  6. Paramagnetism and improved upconversion luminescence properties of NaYF4:Yb,Er/NaGdF4 nanocomposites synthesized by a boiling water seed-mediated route

    Science.gov (United States)

    Yang, Chao-Qing; Li, Ao-Ju; Guo, Wei; Tian, Peng-Hua; Yu, Xiao-Long; Liu, Zhong-Xin; Cao, Yang; Sun, Zhong-Liang

    2016-03-01

    In a route boiling water served as reaction medium, a stoichiometric amount of rare-earth compound and fluoride are put into this system to form α-NaYF4:Yb, Er nuclei. Then prepared sample is heated at elevated temperature to improve the fluorescence intensity, and next a NaGdF4 shell grows on the surface of NaYF4 nuclei. NaYF4:Yb,Er/NaGdF4 core-shell structured upconversion nanoparticles (CSUCNPs) have been successfully synthesized by above route. The use of boiling water decreases the cubic-to-hexagonal phase transition temperature of NaYF4:Yb,Er to 350°C and increases its upconversion (UC) luminescence intensity. A heterogeneous NaGdF4 epitaxially growing on the surface of Ln3+-doped NaYF4 not only improves UC luminescence, but also creates a paramagnetic shell, which can be used as contrast agents in magnetic resonance imaging (MRI). The solution of CSUCNPs shows bright green UC fluorescence under the excitation at 980 nm in a power density only about 50 mW·cm-2. A broad spectrum with a dominant resonance at g of about 2 is observed by the electron paramagnetic resonance (EPR) spectrum of CSUCNPs. Above properties suggest that the obtained CSUCNPs could be potential candidates for dual-mode optical/magnetic bioapplications.

  7. Coupling of Ag Nanoparticle with Inverse Opal Photonic Crystals as a Novel Strategy for Upconversion Emission Enhancement of NaYF4: Yb(3+), Er(3+) Nanoparticles.

    Science.gov (United States)

    Shao, Bo; Yang, Zhengwen; Wang, Yida; Li, Jun; Yang, Jianzhi; Qiu, Jianbei; Song, Zhiguo

    2015-11-18

    Rare-earth-ion-doped upconversion (UC) nanoparticles have generated considerable interest because of their potential application in solar cells, biological labeling, therapeutics, and imaging. However, the applications of UC nanoparticles were still limited because of their low emission efficiency. Photonic crystals and noble metal nanoparticles are applied extensively to enhance the UC emission of rare earth ions. In the present work, a novel substrate consisting of inverse opal photonic crystals and Ag nanoparticles was prepared by the template-assisted method, which was used to enhance the UC emission of NaYF4: Yb(3+), Er(3+) nanoparticles. The red or green UC emissions of NaYF4: Yb(3+), Er(3+) nanoparticles were selectively enhanced on the inverse opal substrates because of the Bragg reflection of the photonic band gap. Additionally, the UC emission enhancement of NaYF4: Yb(3+), Er(3+) nanoparticles induced by the coupling of metal nanoparticle plasmons and photonic crystal effects was realized on the Ag nanoparticles included in the inverse opal substrate. The present results demonstrated that coupling of Ag nanoparticle with inverse opal photonic crystals provides a useful strategy to enhance UC emission of rare-earth-ion-doped nanoparticles.

  8. Structural studies of BaTiO3:Er3+and BaTiO3:Yb3+powders synthesized by hydrothermal method

    Institute of Scientific and Technical Information of China (English)

    Garrido-Hernndez A; Garca-Murillo A; Carrillo-Romo Fde J; Cruz-Santiago LA; Chadeyron G; Morales-Ramrez Ade J; Velumani S

    2014-01-01

    Erbium and ytterbium doped barium titanate nanopowders were prepared using the hydrothermal method. A barium titan-ate structure doped with rare earth ions manifested new characteristics and improved the field of application of optical devices such as trichromatic tubes, LCD displays, lamps, and infrared lasers. In this work, BaTiO3:Er3+and BaTiO3:Yb3+were prepared using barium chloride [BaCl2], titanium butoxide [C16H36O4Ti], erbium chloride [ErCl3] and ytterbium chloride [YbCl3] as precursors. Anhydrous methanol was employed as a solvent. Metallic potassium was used to promote solubility in the system and increase the pH to 13. This method yielded the formation of a predominantly cubic structure in both Er3+and Yb3+doped BaTiO3 powders. Characteristic bond-ings of BaTiO3 were observed with FT-IR spectroscopy. The predominantly cubic structure was confirmed by X-ray diffraction and micro-Raman analyses. The particle size (∼30 nm) was estimated using the Scherrer equation and X-ray diffraction data. The results were presented and discussed.

  9. Hydrothermal synthesis of hexagonal-phase NaYF4: Er, Yb with different shapes for application as photovoltaic up-converters

    Institute of Scientific and Technical Information of China (English)

    Wang Dong-Feng; Zhang Xiao-Dan; Liu Yong-Juan; Wu Chun-Ya; Zhang Cun-Shan; Wei Chang-Chun; Zhao Ying

    2013-01-01

    Hexagonalβ-NaYF4 co-doped with Yb3+ and Er3+ is directly synthesized under mild conditions using a hydrothermal method.The variation of the ratio of Ln3+ to F and ethylenediaminetetraacetic acid (EDTA) causes the shape of the microcrystal to change from microplate to microcolumn.The NaYF4 powder is mixed with polydimethylsiloxane (PDMS)to create an up-converter for thin film amorphous silicon solar cells so as to evaluate the effectiveness of the synthesized material as an up-converter.In order to overcome the difficulty in measuring the effectiveness of up-conversion material,a new method of using near infrared illumination to measure the short circuit current densities of solar cells both with and without up-converters is developed.An up-converter with pure hexagonal NaYF4:yb3+/Er3+ microcrystal produces a high current output.Emission intensity data obtained by photoluminescence suggest that pure hexagonal NaYF4:yb3+/Er3+ microcrystals are more efficient than nanocrystals when used as up-converting phosphors.

  10. Enhanced effect of Er3+ ions on 2.0 and 2.85 μm emission of Ho3+/Yb3+ doped germanate-tellurite glass

    Science.gov (United States)

    Lu, Yu; Cai, Muzhi; Cao, Ruijie; Tian, Ying; Huang, Feifei; Xu, Shiqing; Zhang, Junjie

    2016-10-01

    We report what we believe is the first demonstration of the enhanced Ho3+ 2.0 μm (2.1 times) and 2.85 μm (2.6 times) emission by addition of Er3+ in the Ho3+/Yb3+ co-doped germanate-tellurite (GT) glass with optimized extra-low hydroxyl content ∂OH- (0.118 cm-1). Meanwhile, enhanced 2.0 and 2.85 μm emission cross-sections (5.78 × 10-21 and 17.9 × 10-21 cm2) can be approximately increased 1.5 times higher, respectively. The enhanced 2.0 and 2.85 μm emission upon excitation of a conventional 980 nm laser diode are investigated by the analysis of energy transfer. In addition, the energy transfer mechanism and coefficient (CDA) from Yb3+ to Ho3+ and Er3+ to Ho3+ have been investigated in detail. Our results indicate that Ho3+/Er3+/Yb3+ triply-doped GT glass is a promising material for 2.0 μm and 3 μm fiber laser.

  11. Structural and photoluminescence study of Er-Yb codoped nanocrystalline ZrO{sub 2}-B{sub 2}O{sub 3} solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y nanoestructurados (EMANA), Centro de Investigaciones en Optica, A. C., Loma del Bosque 115, Col. Lomas del Campestre, C.P. 37150 Leon, Gto. (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Grupo de Espectroscopia de Materiales Avanzados y nanoestructurados (EMANA), Centro de Investigaciones en Optica, A. C., Loma del Bosque 115, Col. Lomas del Campestre, C.P. 37150 Leon, Gto. (Mexico); Rodriguez, G. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Vega, M. [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, A.P. 14-805, 07730 Mexico, DF (Mexico)

    2012-09-20

    Codoped Er{sup 3+} and Yb{sup 3+} nanocrystalline ZrO{sub 2}-B{sub 2}O{sub 3} phosphor obtained by a modified sol-gel method is demonstrated. The addition of up to 2.5 mol% B{sub 2}O{sub 3} to nanocrystalline ZrO{sub 2}:Yb(2%), Er(1%) keep the tetragonal rare-earth stabilized ZrO{sub 2} phase; whereas higher B{sub 2}O{sub 3} content destabilize the tetragonal phase, leading to the tetragonal to monoclinic transition with no tetragonal ZrO{sub 2} phase segregation. Visible upconversion of the luminescent active ions, Er{sup 3+} and Yb{sup 3+}, depend strongly on B{sub 2}O{sub 3} content. The PL intensity is strongly quenched for high B{sub 2}O{sub 3} content due to increasing multiphonon relaxation processes related to B-O and B-O-B vibronic modes.

  12. Bright white upconversion luminescence from Er3+/Tm3+/Yb3+-doped titanate-based glasses prepared by aerodynamic levitation method

    Science.gov (United States)

    Zhang, Minghui; Yu, Jianding; Jiang, Wan; Liu, Yan; Ai, Fei; Wen, Haiqin; Jiang, Meng; Yu, Huimei; Pan, Xiuhong; Tang, Meibo; Gai, Lijun

    2017-10-01

    Aerodynamic levitation method was employed to prepare Er3+/Tm3+/Yb3+-doped titanate-based glasses. DTA results show that the glass performs high thermal stability with the glass transition temperature of 799 °C. The interaction among rare earth ions has been discussed by adjusting the relative concentration. Er3+ ions can quench the upconversion luminescence of Tm3+ ions. Tm3+ ions play a strong role in quenching the emissions of Er3+ and Tm3+ when the content of Tm3+ ions is greater than or equal 0.05. From the view of the ratio of red emission to green emission, Tm3+ ions can improve the red emission of Er3+ ions to some extent in contrast with the green emissions of Er3+ ions. 980 nm incident laser can be efficiently absorbed by Yb3+ ions. The relative intensity of red, green, and blue upconversion luminescence has been tuned to obtain white light. The composition with white upconversion luminescence of the color coordinate (0.291, 0.3292) has been found. Moreover, white upconversion luminescence mechanism is a two-photon process of ET, ESA, and cooperative sensitization. Rare earth ions doped titanate-based glasses with bright upconversion luminescence perform potential applications in color display, back light, et al.

  13. Magnetic structures of R{sub 3}Cu{sub 4}Ge{sub 4} (R=Tb, Dy, Ho, Er)

    Energy Technology Data Exchange (ETDEWEB)

    Wawrzynska, E. E-mail: wawrzyn@castor.if.uj.edu.pl; Hernandez-Velasco, J.; Penc, B.; Szytula, A.; Zygmunt, A

    2003-08-01

    Neutron diffraction studies of polycrystalline R{sub 3}Cu{sub 4}Ge{sub 4} (R=Tb, Dy, Ho, Er) intermetallic compounds with the orthorhombic Gd{sub 3}Cu{sub 4}Ge{sub 4}-type crystal structure indicate complex magnetic structures. In these compounds the rare earth atoms occupy two nonequivalent 2d and 4e sublattices. For R=Tb and Er with decreasing temperature the magnetic moments in the 2d sublattice order first; the 4e sublattice magnetic moments order at lower temperatures. For R=Dy, Ho both sublattices order simultaneously although the magnetic moment values are different for each of them. In the compounds with R=Tb and Er a change of the magnetic structure, connected with the 2d sublattice, is observed near the Neel temperature. This is a transition from the commensurate structure, described by the propagation vector k=(0,((1)/(2)),0) at low temperatures to the incommensurate structure with k=(0,((1)/(2))+{delta},0) at higher temperatures (still below the Neel temperature)

  14. Preparation and characterization of Er3+-Yb3+-Ce3+ co-doped transparent glass ceramic containing nano Ca5(PO4)3F crystals

    Institute of Scientific and Technical Information of China (English)

    LI Yongjin; SONG Zhiguo; LI Chen; QIU Jianbei; YANG Zhengwen; YIN Zhaoyi; YANG Yong

    2013-01-01

    A transparent glass ceramic tri-doped with Ce3+/Er3+/yb3+ was fabricated by the high-temperature melting technique and following heat-treatment.X-ray diffraction and transmission electron microscope results demonstrated that Ca5(PO4)3F(FAP) nanocrystals,possessed with preferable emission performances for the 1.54 μm transition for doping Er3+,were homogeneously precipitated among the glass matrix with a mean size of 30 nm.Addition of Ce3+ greatly enhanced 1.54 μm fluorescence of Er3+ by the cross relaxation energy transfer between Er3+ and Ce3+.Meanwhile,incorporation of Ce3+ dramatically decreased the visible upconversion emission intensity of glass ceramic than that of glass,suggesting that Ce3+ might incorporate into the FAP nanocrystals.The properties of this transparent glass ceramic showed the potential application as an efficient 980 nm pumped infrared laser medium.

  15. Crystal growth, transport, and the structural and magnetic properties of Ln(4)FeGa(12) with Ln = Y, Tb, Dy, Ho, and Er.

    Science.gov (United States)

    Drake, Brenton L; Grandjean, Fernande; Kangas, Michael J; Okudzeto, Edem K; Karki, Amar B; Sougrati, Moulay T; Young, David P; Long, Gary J; Chan, Julia Y

    2010-01-18

    Ln(4)FeGa(12), where Ln is Y, Tb, Dy, Ho, and Er, prepared by flux growth, crystallize with the cubic Y(4)PdGa(12) structure with the Im3m space group and with a = 8.5650(4), 8.5610(4), 8.5350(3), 8.5080(3), and 8.4760(3) A, respectively. The crystal structure consists of an iron-gallium octahedra and face-sharing rare-earth cuboctahedra of the Au(3)Cu type. Er(4)Fe(0.67)Ga(12) is iron-deficient, leading to a distortion of the octahedral and cuboctahedral environments due to the splitting of the Ga2 site into Ga2 and Ga3 sites. Further, interstitial octahedral sites that are unoccupied in Ln(4)FeGa(12) (Ln = Y, Tb, Dy, and Ho) are partially occupied by Fe2. Y(4)FeGa(12) exhibits weak itinerant ferromagnetism below 36 K. In contrast, Tb(4)FeGa(12), Dy(4)FeGa(12), Ho(4)FeGa(12), and Er(4)Fe(0.67)Ga(12) order antiferromagnetically with maxima in the molar magnetic susceptibilities at 26, 18.5, 9, and 6 K. All of the compounds exhibit metallic electric resistivity, and their iron-57 Mossbauer spectra, obtained between 4.2 and 295 K, exhibit a single-line absorption with a 4.2 K isomer shift of ca. 0.50 mm/s, a shift that is characteristic of iron in an iron-gallium intermetallic compound. A small but significant broadening in the spectral absorption line width is observed for Y(4)FeGa(12) below 40 K and results from the small hyperfine field arising from its spin-polarized itinerant electrons.

  16. Redox luminescence switch based on Mn(2+) -doped NaYF4 :Yb,Er upconversion nanorods.

    Science.gov (United States)

    Zhang, Liping; Zhang, Jianguo; Chen, Hongqi; Wang, Lun

    2017-09-07

    An redox luminescence switch was developed for the sensing of glutathione (GSH), l-cysteine (Cys) or l-ascorbic acid (AA) based on redox reaction. The Mn(2+) -doped NaYF4 :Yb,Er upconversion nanorods (UCNRs) with an emission peak located in the red region were synthesized. The luminescence intensity of the UCNRs could be quenched due to the Mn(2+) could be oxidized to MnO2 by KMnO4 . Subsequently, when the AA, GSH or Cys was added into the MnO2 modified upconversion nanosystem, which could reduced MnO2 to Mn(2+) and the luminescence intensity was recovered. The concentration ranges of the nanosystem are 0.500-3.375 mM (R(2)  = 0.99) for AA, 0.6250-11.88 mM (R(2)  = 0.99) for GSH and 0.6250-9.375 mM (R(2)  = 0.99) for Cys, respectively. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Synthesis and Characterization of Upconversion Fluorescent Yb3+, Er3+ Doped CsY2F7 Nano- and Microcrystals

    Directory of Open Access Journals (Sweden)

    Helmut Schäfer

    2009-01-01

    Full Text Available Cs Y2F7: 78%   Y3+, 20%   Yb3+, 2%   Er3+ nanocrystals with a mean diameter of approximately 8 nm were synthesized at   185°C in the high boiling organic solvent N-(2-hydroxyethyl-ethylenediamine (HEEDA using ammonium fluoride, the rare earth chlorides and a solution of caesium alkoxide of N-(2-hydroxyethyl-ethylenediamine in HEEDA. In parallel with this approach, a microwave assisted synthesis was carried out which forms nanocrystals of the same material, about 50 nm in size, in aqueous solution at 200∘C/8 bar starting from ammonium fluoride, the rare earth chlorides, and caesium fluoride. In case of the nanocrystals, derived from the HEEDA synthesis, TEM images reveal that the particles are separated but have a broad size distribution. Also an occurred heat-treatment of these nanocrystals (600∘C for 45 minutes led to bulk material which shows highly efficient light emission upon continuous wave (CW excitation at 978 nm. Besides the optical properties, the structure and the morphology of the three products were investigated by means of powder XRD and Rietveld method.

  18. Enhancement of Cerenkov luminescence imaging by dual excitation of Er(3+,Yb(3+-doped rare-earth microparticles.

    Directory of Open Access Journals (Sweden)

    Xiaowei Ma

    Full Text Available Cerenkov luminescence imaging (CLI has been successfully utilized in various fields of preclinical studies; however, CLI is challenging due to its weak luminescent intensity and insufficient penetration capability. Here, we report the design and synthesis of a type of rare-earth microparticles (REMPs, which can be dually excited by Cerenkov luminescence (CL resulting from the decay of radionuclides to enhance CLI in terms of intensity and penetration.Yb(3+- and Er(3+- codoped hexagonal NaYF4 hollow microtubes were synthesized via a hydrothermal route. The phase, morphology, and emission spectrum were confirmed for these REMPs by power X-ray diffraction (XRD, scanning electron microscopy (SEM, and spectrophotometry, respectively. A commercial CCD camera equipped with a series of optical filters was employed to quantify the intensity and spectrum of CLI from radionuclides. The enhancement of penetration was investigated by imaging studies of nylon phantoms and nude mouse pseudotumor models.the REMPs could be dually excited by CL at the wavelengths of 520 and 980 nm, and the emission peaks overlaid at 660 nm. This strategy approximately doubled the overall detectable intensity of CLI and extended its maximum penetration in nylon phantoms from 5 to 15 mm. The penetration study in living animals yielded similar results.this study demonstrated that CL can dually excite REMPs and that the overlaid emissions in the range of 660 nm could significantly enhance the penetration and intensity of CL. The proposed enhanced CLI strategy may have promising applications in the future.

  19. Hexagonal versus perovskite phase of manganite RMnO3 (R=Y,Ho,Er,Tm,Yb,Lu)

    Science.gov (United States)

    Zhou, J.-S.; Goodenough, J. B.; Gallardo-Amores, J. M.; Morán, E.; Alario-Franco, M. A.; Caudillo, R.

    2006-07-01

    The floating-zone method and high-pressure synthesis have been used to obtain the hexagonal and the perovskite RMnO3 (R=Y,Ho,Er,Tm,Yb,Lu) compounds. We have refined the crystal structure and characterized the compounds with measurements of magnetic susceptibility χ(T) and thermal conductivity κ(T) . The systematic change of κ(T) below TN found in all members of the hexagonal RMnO3 family shows that some spin-independent bond-length fluctuation plays an important role in the suppression of κ(T) below TN as well as in the paramagnetic phase. The responsible soft vibrational mode is identified. In contrast, the perovskite RMnO3 shows a phonon-like κ(T) below room temperature, but with an anomalously large critical scattering at TN . A phase diagram of transition temperatures versus the R3+ -ion radius for both hexagonal and perovskite phases is also given.

  20. Electron-magnon interaction in RNiBC (R=Er, Ho, Dy, Tb, and Gd) series of compounds based on magnetoresistance measurements

    Science.gov (United States)

    Fontes, M. B.; Trochez, J. C.; Giordanengo, B.; Bud'ko, S. L.; Sanchez, D. R.; Baggio-Saitovitch, E. M.; Continentino, M. A.

    1999-09-01

    We present a study of the transport and magnetic properties of a series of RNiBC compounds (R=Er, Ho, Dy, Tb, and Gd). All the materials investigated have long range magnetic order at sufficiently low temperatures. Magnetoresistance measurements are presented for a large range of temperatures (T) and magnetic fields (H). We show that below the critical temperature, the temperature dependence of the resistivity is determined by electron scattering due to the elementary excitations (spin waves) of the ordered magnetic phase and the values of the gap in the magnon spectra were derived. Finally we discuss the H×T phase diagram of these materials.

  1. Investigation about thermophysical properties of Ln{sub 2}Ce{sub 2}O{sub 7} (Ln = Sm, Er and Yb) oxides for thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Hongsong, Zhang, E-mail: zhs761128@163.com [Department of Mechanical Engineering, Henan Institute of Engineering, Zhengzhou 450007 (China); Jianguo, Lv [City College, Kunming University of Science and Technology, Kunming 650050 (China); Gang, Li; Zheng, Zhang; Xinli, Wang [Department of Mechanical Engineering, Henan Institute of Engineering, Zhengzhou 450007 (China)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► We successfully prepared three types of new rare earth cerium oxides. ► We measured their thermophysical properties. ► These new ceramics can be explored as candidate ceramics for thermal barrier coatings. -- Abstract: Three kinds of rare earth cerium oxides – Ln{sub 2}Ce{sub 2}O{sub 7} (Ln = Sm, Er and Yb) were prepared by solid state reaction method. Their phase compositions, microstructures and thermophysical properties were investigated. Results of X-ray diffraction reveal that pure Ln{sub 2}Ce{sub 2}O{sub 7} (Ln = Sm, Er and Yb) oxides with fluorite structure are successfully synthesized in the current research. Scanning electrical microscopy results show that their microstructures are dense and no other un-reacted oxides or inter-phases exist in the interfaces between grains. Their thermal expansion coefficients are higher than those of YSZ, while their thermal conductivities are lower than those of YSZ. The decreasing ionic radius from Sm{sup 3+} to Yb{sup 3+} results in the descending thermal expansion coefficients from Sm{sub 2}Ce{sub 2}O{sub 7} to Yb{sub 2}Ce{sub 2}O{sub 7}. The effective phonon scattering by atomic weight difference contributes to the decreasing thermal conductivities from Sm{sub 2}Ce{sub 2}O{sub 7} to Yb{sub 2}Ce{sub 2}O{sub 7}. These results imply that synthesized rare earth cerium oxides have potentials to be used as novel candidate materials for thermal barrier coatings in the future.

  2. Polarized spectroscopic properties of Er3+:Gd2SiO5 crystal and evaluation of Er3+:Yb3+:Gd2SiO5 crystal as a 1.55 μm laser medium

    Science.gov (United States)

    Wang, H.; Huang, J. H.; Gong, X. H.; Chen, Y. J.; Lin, Y. F.; Luo, Z. D.; Huang, Y. D.

    2016-10-01

    An Er3+-doped Gd2SiO5 single crystal with high optical quality has been grown by the Czochralski method. Polarized absorption and fluorescence spectra and fluorescence lifetime of the crystal were measured at room temperature. Intensity parameters, spontaneous emission probabilities, fluorescence branching ratios, and radiative lifetimes were estimated on the basis of the Judd-Ofelt theory. Besides, potentiality of 1.55 μm laser emission in an Er3+-Yb3+ co-doped Gd2SiO5 crystal was evaluated.

  3. Growth, structure, defects and polarized absorption spectral properties of Er:Yb:YCa{sub 4}O(BO{sub 3}){sub 3} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Degao, E-mail: qduzhdg@163.com [College of Physics, Qingdao University, Qingdao 266071 (China); Institute of Complexity Science, Qingdao University, Qingdao 266071 (China); Teng, Bing, E-mail: 5108tb@163.com [College of Physics, Qingdao University, Qingdao 266071 (China); Key Laboratory of Photonics Materials and Technology in Universities of Shandong (Qingdao University), Qingdao 266071 (China); Kong, Weijin; Zhang, Shiming; Li, Yuyi [College of Physics, Qingdao University, Qingdao 266071 (China); Key Laboratory of Photonics Materials and Technology in Universities of Shandong (Qingdao University), Qingdao 266071 (China); Li, Jianhong [CRYSTECH Inc., 266107 Qingdao (China); Yang, Liting; Cao, Lifeng [College of Physics, Qingdao University, Qingdao 266071 (China); Key Laboratory of Photonics Materials and Technology in Universities of Shandong (Qingdao University), Qingdao 266071 (China); Van Smaalen, Sander [Laboratory of Crystallography, University of Bayreuth, Bayreuth 95447 (Germany)

    2016-01-15

    YCa{sub 4}O(BO{sub 3}){sub 3} (YCOB) crystals co-doped with 3 at% Er{sup 3+} and 20 at% Yb{sup 3+} were successfully grown by the Czochralski method. X-ray powder diffraction (XRPD) results show that the as-grown Er:Yb:YCOB crystal belongs to the monoclinic system with space group Cm. And the lattice parameters are a=8.076(8) Å, b=16.023(7) Å, c=3.528(4) Å and β=101.15(4)°. Crystal defects were revealed by chemical etching experiments. The density of etch pits, attributed to dislocations and observed on (010) planes, was found to be not uniform along the crystal diameter. The detailed polarized absorption spectra were measured. The polarized absorption cross sections at 977 nm are 1.01×10{sup −20}, 1.22×10{sup −20} and 1.05×10{sup −20} cm{sup 2} for E//X, E//Y and E//Z, respectively. And the polarized absorption cross sections at 1538 nm is about 1.86×10{sup −20} cm{sup 2} for both E//X and E//Z, but for E//Y the result is 1.03×10{sup −20} cm{sup 2}, which is much smaller. The relationship between the crystal structure and absorption spectra was discussed. - Graphical abstract: The as-grown bulk Er:Yb:YCOB crystal (the long axis is along the b-axis) and LeBail fit to the XRPD pattern of Er:Yb:YCOB (top) compared to the diffraction pattern of YCOB from the JCPDS data bank (bottom). Reflection markers indicate the calculated reflection positions. The middle trace gives the difference between observed and calculated intensity. Reflection indices corresponding to the strongest diffraction peaks are marked on the experimental pattern. - Highlights: • Er:Yb:YCOB crystal with a new composition was grown. • XRPD and FT-IR showed a certain degree of deformation in the crystal structure. • Detailed polarized absorption cross sections at 977 nm and 1538 nm were calculated. • Crystal defects were clearly revealed by chemical etching experiments.

  4. Optical Spectroscopy of Er3+ and Er3+/Yb3+ Co-doped Bi2O3-GeO2-B2O3-ZnO Glasses

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The (60-x)Bi2O3-xGeO2-30B2O3-10ZnO (x=5, 10, 20, 30 molar percent) glasses doped with Er3+ and Er3+/Yb3+ were fabricated using the melting method. The thermal stability of the glasses was studied with their DTA curves. The results show that the difference between the glass transition temperature and the crystallization onset temperature increases with the increase of GeO2 content, indicating that the thermal stability of the glass has become better. The absorption spectra were recorded and the stimulated emission cross sections were calculated using the McCumber theory. The Ω2, Ω4, and Ω6 parameters,the transition probability, the radiative lifetime, and the fluorescence branch ratio of Er3+ for optical transition were calculated from their absorption spectra in terms of reduced matrix U(t) (λ=2, 4, 6) character for optical transitions. The infrared emission of Er3+ was measured upon excitation with 970 nm light and the full width at half-maximum (FWHM) was estimated from the emission spectra. The pumping efficiency and the intensity of the emission at the 1.54 μm band of Er3+ were enhanced considerably by co-doping Yb3+.

  5. Tunable ultraviolet/visible to near-infrared down-conversion luminescence in the Er3+, Yb3+ co-doped (Y0.88La0.09Zr0.03)2O3 transparent ceramics

    Science.gov (United States)

    Hu, Yue; Shahid, Muhammad; Pan, Wei

    2017-10-01

    Herein, we report an efficient ultraviolet/visible to near-infrared (NIR) down-conversion luminescence phenomenon in transparent Er3+, Yb3+ co-doped (Y0.88La0.09Zr0.03)2O3 ceramics. Almost fully densified (Y0.88La0.09Zr0.03)2O3 transparent ceramic has been prepared by vacuum sintering at 1800 °C with different contents of Er3+ and Yb3+ elements. The intensity ratio of Yb3+: 2F5/2 → 2F7/2 emission (∼1000 nm) to the Er3+: 4I13/2 → 4I15/2 emission (∼1550 nm) has been tuned by adjusting the excitation wavelength. Phonon-assist quantum cutting from the 4G11/2 level of Er3+ with two energy transfer (ET) processes to Yb3+ has been determined, which enhances the Yb3+ emission around the wavelength of 1000 nm. It is found that when one photon around 379 nm is absorbed, two photons around 1000 nm will be emitted, and hence the quantum efficiency is estimated to be ∼182% in this transparent ceramics. The mechanism of the visible to near-infrared (NIR) down-conversion luminescence in the Er3+, Yb3+ co-doped (Y0.88La0.09Zr0.03)2O3 ceramics has been discussed.

  6. Biocompatibility of fluorescent nanoparticles NaYF4:Yb,Er as imaging media%荧光纳米颗粒NaYF4:Yb,Er作为显像介质的生物相容性

    Institute of Scientific and Technical Information of China (English)

    虞永江; 马晓荣; 于国鹏; 高同斌; 齐隽; 陈方

    2011-01-01

    Objective To investigate the biocompatibility of upconversion fluorescent nanoparticles in vivo and in vitro, and verify its safety as imaging media.Methods Mouse bone mesenchymal stem cells (BMSC), mouse embryonic fibroblasts (NIH/3T3) and primary myoblasts (C2C12) were incubated with different concentrations of NaYF4: Yb, Er (0, 10, 50, 100 and 200 μg/mL).Cell proliferation was determined by MTT assay, and the formation of myotube cells from C2C12 myoblasts was detected.DMEM with NaYF4: Yb, Er nanoparticles were injected into C57BL/6 mice, and liver function and renal function were examined.HE staining was performed for main body organs, and toxicity was detected.Results MTT assay revealed that the cytotoxicity of NaYF4: Yb, Er on NIH/3T3 and C2C12 was positively correlated with incubation dose and time ( NIH/3T3: r =0.974, P <0.05; C2C12: r =0.996, P <0.05), while the same result was not found for BMSC ( r = - 0.218, P > 0.05).The formation of myotube cells from C2C12 myoblasts was not significantly affected by incubation with NaYF4: Yb, Er for 48 h.No obvious damage of liver and renal function and main body organs was observed after injection of DMEM with NaYF4: Yb, Er nanoparticles in mice.Conclusion As biological luminescent labels with strong intensity, NaYF4: Yb, Er has less toxicity both in vivo and in vitro to the requirement of imaging, and is an ideal biological imaging media.%目的 检测上转频荧光纳米颗粒的生物学体内、外相容性,证实其作为显像介质的生物安全性.方法 将培育后的小鼠骨髓间充质干细胞(BMSC)、胚胎成纤维细胞(NIH/3T3)及成肌细胞(C2C12)分别与不同浓度(0、10、50、100、200μg/mL)的NaYF4:Yb,Er共孵育,采用MTT法检测细胞的增殖活性,并测定C2C12成肌细胞形成肌管细胞的功能.将NaYF4:Yb,Er纳米颗粒DMEM混悬液注射入C57BL/6小鼠,行小鼠肝肾功能测定;并对重要脏器行HE组织学染色,检测小鼠的体内毒性.结果 MTT法细

  7. Tunable emissions from Dy{sup 3+}/Sm{sup 3+} ions co-activated SrY{sub 2}O{sub 4}:Er{sup 3+} nanocrystalline phosphors for LED and FED applications

    Energy Technology Data Exchange (ETDEWEB)

    Pavitra, E.; Seeta Rama Raju, G.; Yu, Jae Su, E-mail: jsyu@khu.ac.kr

    2014-04-01

    Highlights: • RE ions triple-doped SrY{sub 2}O{sub 4} nanocrystalline phosphors were prepared by sol–gel process. • SrY{sub 2}O{sub 4}:Er{sup 3+} ions single-doped phosphor exhibits deep green emission under NUV excitation. • Dy{sup 3+}/Er{sup 3+} ions co-doped phosphor shows yellowish-green emission under 365 nm excitation. • Er{sup 3+}/Dy{sup 3+}/Sm{sup 3+} triple-ions doped phosphor displays pleasant white emission for LEDs. • From CL, the triple-ions doped phosphor gives warm-white emission for FED applications. - Abstract: Er{sup 3+} ions single-doped, Dy{sup 3+}/Er{sup 3+} ions co-doped, and Er{sup 3+}/Dy{sup 3+}/Sm{sup 3+} ions triple-doped SrY{sub 2}O{sub 4} nanocrystalline phosphors were synthesized by a citrate sol–gel method. X-ray diffraction patterns confirmed their pure orthorhombic structure after annealed at 1300 °C and the morphology of particles was found to be nearly spherical. The Er{sup 3+} ions single-doped phosphor samples showed an intense green emission band around 548 nm and the concentration quenching occurred at dilute concentrations (1 mol%) because the {sup 4}S{sub 3/2} energy state of Er{sup 3+} ions can be easily quenched by means of cross relaxation to a metastable state. The Dy{sup 3+}/Er{sup 3+} ions co-doped phosphors exhibited a classic yellowish green emission due to efficient energy transfer from Dy{sup 3+} to Er{sup 3+} ions under 365 nm excitation. By adding a series of Sm{sup 3+} ions to the Dy{sup 3+}/Er{sup 3+} ions co-doped SrY{sub 2}O{sub 4} phosphors, a pleasant white light emission which is essential for white light-emitting diodes was obtained. Likewise, from the cathodoluminescence measurements, a warm white light emission that is required for field-emission displays was achieved with accelerating voltage of 5 kV and filament current of 55 μA. A possible energy transfer mechanism was discussed and the energy transfer efficiencies were also calculated.

  8. Infrared, visible and upconversion emission of CaAl12O19 powders doped with Er3+, Yb3+ and Mg2+ ions

    Science.gov (United States)

    Singh, V.; Rai, V. K.; Lee, I.-J.; Ledoux-Rak, I.; Al-Shamery, K.; Nordmann, J.; Haase, M.

    2012-01-01

    CaAl12O19 powders doped with Er3+, Yb3+, and Mg2+ ions have been prepared by a low-temperature combustion synthesis technique. Formation and chemical compositions were analysed by powder X-ray diffraction and energy-dispersive spectroscopy. The visible luminescence spectra of the doped phosphor upon excitation with ˜378 nm radiation from a Xenon lamp have been studied. A broad band emission in the range of 1400-1700 nm with a peak around 1.5 µm and FWHM of about ˜80 nm responsible for the eye-safe telecommunication window has been observed upon direct excitation with a NIR laser into the 4I11/2 level of Er3+. The effect of co-doping with Yb3+ and Mg2+ ions in the CaAl12O19:Er3+ matrix on the photoluminescence intensity corresponding to the 2H11/2,4S3/2→4I15/2, 4F9/2→4I15/2 and 4I13/2→4I15/2 transitions of Er3+ is elaborated and discussed in detail.

  9. Growth and spectral properties of a promising laser crystal Yb3+/Er3+:Ca9La(VO4)7

    Science.gov (United States)

    Li, Ming; Sun, Shijia; Zhang, Lizhen; Yuan, Feifei; Huang, Yisheng; Lin, Zhoubin

    2016-10-01

    A new crystal of Er3+/Yb3+:Ca9La(VO4)7 was grown successfully by the Czochralski method. Its spectral properties were investigated in detail. The crystal has a strong absorption band near 980 nm with a full-width at half-maximum of 33 nm, which means that it is very suitable for InGaAs laser diode pumping. Based on the Judd-Ofelt theory, the intensity parameters and radiative lifetime were obtained. The fluorescence lifetime of the 4I13/2 level of the Er3+ ion is 4.28 ms. The emission cross sections of the Er3+ ion at 1533 nm calculated by the Füchtbauer-Ladenburg method are 0.86 × 10-20 cm2 and 1.08 × 10-20 cm2 for σ- and π- polarization, respectively. The results indicate that Er3+/Yb3+:Ca9La(VO4)7 crystal is a potential 1.5-1.6 μm laser material.

  10. Upconversion emission and cathodoluminescence of Er{sup 3+}-doped NaYbF{sub 4} nanoparticles for low-temperature thermometry and field emission displays

    Energy Technology Data Exchange (ETDEWEB)

    Du, Peng; Yu, Jae Su [Kyung Hee University, Department of Electronics and Radio Engineering, Yongin (Korea, Republic of); Luo, Laihui [Ningbo University, Department of Microelectronic Science and Engineering, Ningbo (China)

    2017-03-15

    The Er{sup 3+}-doped NaYbF{sub 4} nanoparticles were fabricated by a hydrothermal method. The green and red emissions located at around 525, 542 and 657 nm corresponding to the {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} transitions of Er{sup 3+} ions, respectively, were observed when pumped at 980 nm light. Furthermore, with the help of the fluorescence intensity ratio technique, the thermometric properties of as-prepared products from the thermally coupled {sup 2}H{sub 11/2} and {sup 4}S{sub 3/2} levels of Er{sup 3+} ions were studied by analyzing temperature-dependent upconversion (UC) emission spectra. The maximum sensitivity for the Er{sup 3+}-doped NaYbF{sub 4} nanoparticles was found to be around 0.0043 K{sup -} {sup 1} with a temperature range of 93-293 K. In addition, the cathodoluminescence (CL) spectrum of the synthesized nanoparticles was nearly the same as the UC emission spectrum and the CL emission intensity did not exhibit saturation with the increase of accelerating voltage and filament current. (orig.)

  11. Structural and waveguiding characteristics of Er3+:Yb3Al5-yGayO12 films grown by the liquid phase epitaxy

    Science.gov (United States)

    Hlásek, T.; Rubešová, K.; Jakeš, V.; Nekvindová, P.; Kučera, M.; Daniš, S.; Veis, M.; Havránek, V.

    2015-11-01

    Erbium (Er3+) doped ytterbium garnet (Er:Yb3Al5-yGayO12; y = 0, 0.55 and 1.1) single crystalline thick films have been grown by the low-temperature liquid phase epitaxy method (LPE). The composition of the films was determined using the high resolution XRD, the particle-induced X-ray emission spectroscopy (PIXE) and the particle-induced gamma-ray emission spectroscopy (PIGE). The lattice mismatch between films and substrates was investigated by the high-resolution X-ray diffraction. The surface analysis was carried out by the atomic force microscopy (AFM). Pure infrared emission of Er3+ ions was observed in all films containing gallium. The characteristics such as refractive index, thickness and light propagation were studied by the m-line spectroscopy (MLS) using several wavelengths (633, 964, 1311 and 1552 nm). All samples, where y = 1.1, were multimode waveguides. For these reasons, the Er:Yb3Al3.9Ga1.1O12 seems to be a promising material for light amplifiers in the IR region.

  12. Hydrothermal synthesis of superparamagnetic and red luminescent bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er core@shell monodisperse nanoparticles and their subsequent ligand exchange in water

    Science.gov (United States)

    Qin, Zhenli; Du, Sinan; Luo, Yang; Liao, Zhijian; Zuo, Fang; Luo, Jianbin; Liu, Dong

    2016-08-01

    We report the use of an efficient hydrothermal method to synthesize superparamagnetic and red luminescent bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er nanoparticles (NPs) with core@shell structures via a seed-growth procedure. Oleic acid coated Fe3O4 (OA-Fe3O4) NPs were initially synthesized using a coprecipitation method. The as-synthesized OA-Fe3O4 NPs were then used as seeds, on which the red upconversion luminescent shell (Mn2+-doped NaYF4:Yb/Er) was formed. Furthermore, hydrophobic to hydrophilic surface modification of the Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs was achieved via a ligand exchange method where oleic acid was displaced by a PEG phosphate ligand [PEG = poly(ethylene glycol)]. These materials were characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, and vibrating sample magnetometry (VSM). The Fe3O4 cores were uniformly coated with a Mn2+-doped NaYF4:Yb/Er shell, and the bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs were monodispersed. Furthermore, the Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs exhibited a saturated magnetization value of 6.2 emu/g and emitted red luminescence under a 980 nm laser. The obtained bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs may find potential applications in drug targeting, bioseparation, and diagnostic analysis. The synthetic method may be employed for the preparation of other bifunctional nanomaterials.

  13. Tuning from green to red the upconversion emission of Y{sub 2}O{sub 3}:Er{sup 3+}-Yb{sup 3+} nanophosphors

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Torres, L.A. [Centro de Investigaciones en Optica, Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (GEMANA), A. P. 1-948, Leon, GTO (Mexico); Salas, P.; Resendiz-L, E.; Rodriguez-Gonzalez, C. [Universidad Nacional Autonoma de Mexico, Centro de Fisica Aplicada y Tecnologia Avanzada, Apartado Postal 1-1010, Queretaro, QRO (Mexico); Oliva, J. [Conacyt-Facultad Ciencias Quimicas Universidad Autonoma de Coahuila, Saltillo, Coahuila (Mexico); Meza, O. [Benemerita Universidad Autonoma de Puebla, Instituto de Fisica, A.P. J-48, Centro Historico, PUE (Mexico)

    2017-01-15

    In this work, the structural, morphological and luminescent properties of Y{sub 2}O{sub 3} nanophosphors doped with Er{sup 3+} (1 mol%) and different Yb{sup 3+} concentrations (2-12 mol%) have been studied. Those nanophosphors were synthesized using a simple hydrothermal method. XRD analysis indicates that all the samples presented a pure cubic phase even for Yb concentrations as high as 12 mol%. In addition, SEM images show nanoparticles with quasi-spherical shapes with average sizes in the range of 300-340 nm. Photoluminescence measurements obtained after excitation at 967 nm revealed that our samples have strong green (563 nm) and red emissions (660 nm) corresponding to {sup 2}H{sub 11/2} + {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} transitions of Er{sup 3+} ions, respectively. We also observed that the green band is quenched and the red emission enhanced as the Yb concentration increases. In consequence, the CIE coordinates changed from (0.35, 0.64) in the green region to (0.59, 0.39) in the red region. Thus, the tuning properties of Y{sub 2}O{sub 3} nanophosphors suggest that they are good candidates for applications in lighting. (orig.)

  14. Synthetic and spectroscopic studies of vanadate glaserites I: Upconversion studies of doubly co-doped (Er, Tm, or Ho):Yb:K{sub 3}Y(VO{sub 4}){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kimani, Martin M., E-mail: kimani@g.clemson.edu; Chen, Hongyu, E-mail: hongyuc@g.clemson.edu; McMillen, Colin D., E-mail: cmcmill@g.clemson.edu; Anker, Jeffery N., E-mail: janker@clemson.edu; Kolis, Joseph W., E-mail: kjoseph@clemson.edu

    2015-03-15

    The synthesis and upconversion properties of trigonal glaserite-type K{sub 3}Y(VO{sub 4}){sub 2} co-doped with Er{sup 3+}/Yb{sup 3+}, Ho{sup 3+}/Yb{sup 3+}, or Tm{sup 3+}/Yb{sup 3+} were studied. Powder samples were synthesized by solid state reactions at 1000 °C for 48 h, while well-formed hexagonal single crystals of the same were grown hydrothermally using 10 M K{sub 2}CO{sub 3} at 560–650 °C. Infrared-to-visible upconversion by Er{sup 3+}/Yb{sup 3+}, Ho{sup 3+}/Yb{sup 3+}, or Tm{sup 3+}/Yb{sup 3+} codoped-K{sub 3}Y(VO{sub 4}){sub 2} glaserite powder and single crystals was observed, and the upconversion spectral properties were studied as a function of different Er{sup 3+}, Tm{sup 3+}, Ho{sup 3+}, and Yb{sup 3+} ion concentrations. The process is observed under 980 nm laser diode excitation and leads to strong green (552 nm) and red (659 nm) emission for Er{sup 3+}/Yb{sup 3+}, green (549 nm) and red (664 nm) emission for Ho{sup 3+}/Yb{sup 3+}, and blue (475 nm) and red (647 nm) emission for Tm{sup 3+}/Yb{sup 3+}. The main mechanism that allows for up-conversion is attributed the energy transfer among Yb{sup 3+} and the various Er{sup 3+}/Ho{sup 3+}/Tm{sup 3+} ions in excited states. These results illustrate the large potential of co-doped alkali double vanadates for photonic applications involving optoelectronics devices. - Graphical abstract: Synthesis and upconversion in vanadate glaserites. - Highlights: • K{sub 3}Y(VO{sub 4}){sub 2} codoped with Er, Tm, or Ho:Yb were synthesized via solid-state and hydrothermal routes. • Upconversion properties are investigated. • The codoped compounds revealed efficient infrared-to-visible upconversion. • The presented compounds are potential host for solid state lighting.

  15. Magnetic ordering of R{sub 3}Cu{sub 4}Sn{sub 4} (R = Tb, Dy, Ho and Er)

    Energy Technology Data Exchange (ETDEWEB)

    Wawrzynska, E [M Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Cracow (Poland); Hernandez-Velasco, J [BENSC, Hahn-Meitner Institut, Glienicker Strasse 100, D-14109 Berlin (Germany); Penc, B [M Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Cracow (Poland); Sikora, W [Faculty of Physics and Nuclear Techniques, University of Mining and Metallurgy, Reymonta 19, 30-059 Cracow (Poland); Szytula, A [M Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Cracow (Poland); Zygmunt, A [W Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Dorodna 2, 50-950 Wroclaw (Poland)

    2003-08-06

    Neutron diffraction studies of polycrystalline R{sub 3}Cu{sub 4}Sn{sub 4} (R = Tb, Dy, Ho, Er) intermetallic compounds with the orthorhombic Gd{sub 3}Cu{sub 4}Ge{sub 4}-type crystal structure indicate the existence of different magnetic structures. Rare earth atoms occupy two non-equivalent 2d and 4e sublattices. The rare earth magnetic moments order at low temperatures. For R = Tb and Dy the magnetic structures below the Neel temperature are described by the propagation vectors k = (0, 0, 1/2 + {delta}). In these compounds both rare earth sublattices order. For R = Ho the magnetic structure is more complicated. There are two vectors; one of them is k = (0, 1/2, 0) whereas the second one changes with temperature. For the Er compound there is the propagation vector k = (1/2, 1/2, 0) which describes the magnetic ordering in the 2d sublattice and at low temperatures is accompanied by the propagation vector k = (0, 0,{delta}) describing the ordering in the 4e sublattice.

  16. Magnetic structures of R{sub 3}Cu{sub 4}Si{sub 4} (R=Dy, Ho and Er)

    Energy Technology Data Exchange (ETDEWEB)

    Wawrzynska, E. E-mail: e.w.@wp.pl; Hernandez-Velasco, J.; Penc, B.; Szytula, A. E-mail: szytula@if.uj.edu.pl

    2004-09-01

    Polycrystalline samples of R{sub 3}Cu{sub 4}Si{sub 4} (R=Dy, Ho, Er) intermetallics were studied with neutron diffraction methods. All of them crystallize in the orthorhombic structure of Gd{sub 3}Cu{sub 4}Ge{sub 4}-type and order antiferromagnetically at low temperatures. Magnetic moments localized at the rare earth atoms, that occupy two non-equivalent 2d and 4e sublattices, order simultaneously in Dy{sub 3}Cu{sub 4}Si{sub 4}. The order is described by the propagation vector k=(0,((1)/(2)),0) accompanied by k=(0,(1/2)+{delta},(1/2)+{delta}), {delta}=0.025(2). In Ho{sub 3}Cu{sub 4}Si{sub 4} two propagation vectors are needed to model the magnetic order. These are: k=((1/2),0.316(2),(1/2)) for the 4e sublattice, which disorders as the first when the temperature increases, and k=(0,(1/2),0) for the 2d sublattice. A similar situation is observed for Er{sub 3}Cu{sub 4}Si{sub 4} where the propagation vectors are: k=(0,1-{delta},0), {delta}=0.097(2) for the 4e sublattice, which disorders as the first with increasing temperature, and k=(0,(1/2)+{delta},0), {delta}=0.0015(6) for the 2d sublattice.

  17. Magnetic Ground States of the Rare-Earth Tripod Kagome Lattice Mg_{2}RE_{3}Sb_{3}O_{14} (RE=Gd,Dy,Er).

    Science.gov (United States)

    Dun, Z L; Trinh, J; Li, K; Lee, M; Chen, K W; Baumbach, R; Hu, Y F; Wang, Y X; Choi, E S; Shastry, B S; Ramirez, A P; Zhou, H D

    2016-04-15

    We present the structural and magnetic properties of a new compound family, Mg_{2}RE_{3}Sb_{3}O_{14} (RE=Gd,Dy,Er), with a hitherto unstudied frustrating lattice, the "tripod kagome" structure. Susceptibility (ac, dc) and specific heat exhibit features that are understood within a simple Luttinger-Tisza-type theory. For RE=Gd, we found long-ranged order (LRO) at 1.65 K, which is consistent with a 120° structure, demonstrating the importance of diople interactions for this 2D Heisenberg system. For RE=Dy, LRO at 0.37 K is related to the "kagome spin ice" physics for a 2D system. This result shows that the tripod kagome structure accelerates the transition to LRO predicted for the related pyrochlore systems. For RE=Er, two transitions, at 80 mK and 2.1 K are observed, suggesting the importance of quantum fluctuations for this putative XY system.

  18. Towards broad range and highly efficient down-conversion of solar spectrum by Er{sup 3+}-Yb{sup 3+} co-doped nano-structured glass-ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, V.D.; Mendez-Ramos, J. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, E-38206 La Laguna, Tenerife (Spain); Tikhomirov, V.K.; Moshchalkov, V.V. [INPAC-Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven (Belgium); Yanes, A.C. [Departamento de Fisica Basica, Universidad de La Laguna, E-38206 La Laguna, Tenerife (Spain)

    2010-10-15

    The efficiency of semiconductor solar cells could be greatly increased by down-conversion processes, which efficiently split incident solar photons into couples of photons with energy over the bandgap. Here, we show new down-conversion mechanisms in Er{sup 3+}-Yb{sup 3+} co-doped glass-ceramics, where the ions are hosted by fluoride nanoparticles embedded in silica glass. By this means, 350-550 nm photons, absorbed by Er{sup 3+} ions, generate pairs of photons at the range of 650-1550 nm, emitted by Er{sup 3+} and Yb{sup 3+}, with a quantum efficiency approaching the maximum of 200%. (author)

  19. Synthesis of YF3∶Yb3+/Er3+ Nanocrystals Coped SDS and Fluorescent Properties%SDS包裹的YF3∶Yb3+/Er3+纳米晶的制备及荧光性质研究

    Institute of Scientific and Technical Information of China (English)

    张艺

    2013-01-01

    在乙醇和乙二醇的混合溶剂中,用溶剂热法,150℃条件下,反应24h制备了YF3∶Yb3+/Er3+纳米晶(JCPDS号为74-0911),并一步制备出YF3∶Yb3+/Er3+@SDS纳米粒子.激发光源的波长980nm,YF3∶Yb3+/Er3+@SDS纳米晶有强的上转换发光,发射峰的位置为550nm,666nm 和833nm,分别对应Er3+离子的4S3/2→4I15/2,4F9/2→4I15/2和4S3/2-→4I13/2跃迁.

  20. Structural and spectroscopic behavior of Er{sup 3+}:Yb{sup 3+} co-doped lithium telluroborate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Annapoorani, K. [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India); Maheshvaran, K. [Department of Physics, K.S. Rangasamy College of Technology, Trichengode 637215 (India); ArunKumar, S. [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India); Suriya Murthy, N. [Radiological Safety Division, IGCAR, Kalpakkam 603102 (India); Soukka, Tero [Department of Biotechnology, University of Turku (Finland); Marimuthu, K., E-mail: mari_ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India)

    2015-01-15

    A new series of Er{sup 3+}:Yb{sup 3+} co-doped Lithium telluroborate glasses were prepared following the melt quenching technique. The structural analyzes were made through XRD, Raman, FTIR spectra to explore the different vibrations of borate and tellurite network. The absorption spectra have been used to determine the nature of the metal–ligand and further Band gap and Urbach's analysis have also been carried out. The oscillator strength value of the {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2} hypersensitive transition is found to be higher and increases as the concentration of the RE ion increases which emphasis the asymmetry nature of the glasses. The magnitude of the JO intensity parameters follow the trend as Ω{sub 2}>Ω{sub 4}>Ω{sub 6} uniformly for all the prepared glasses. A bright green emission corresponding to the {sup 2}H{sub 11/2}+{sup 4}S{sub 3/2}→ {sup 4}I{sub 15/2} transition and luminescence from {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} in eye safe region have also been observed. The radiative parameters such as radiative transition probability, stimulated emission cross-section, branching ratios, radiative lifetime, gain bandwidth and gain linewidth for the {sup 4}S{sub 3/2} and {sup 4}I{sub 13/2} level of the title glasses have also been determined. The absorption and emission cross-section corresponding to the {sup 4}I{sub 13/2} level has been calculated using McCumber theory. Lifetime measurements were made under 980 nm excitation and the quantum efficiency were also calculated to evaluate the appropriateness of the host matrix for the fabrication of laser materials and broad band amplifiers.

  1. PNBE-supported metallopolymer-type optical materials through grafting of Zn-Ln (Ln = Nd, Yb or Er) benzimidazole complex monomers with efficient NIR luminescence

    Science.gov (United States)

    Liu, Lin; Li, Hongyan; Feng, Weixu; Fu, Guorui; Lü, Xingqiang; Wong, Wai-Kwok; Jones, Richard A.

    2017-02-01

    Through the ring-opening metathesis polymerization (ROMP) of norbornene (NBE) with each of obtained allyl-containing complex monomers [Zn(L)2(Py)Ln(NO3)3] (Ln = La, 1; Nd, 2; Yb, 3; Er, 4 or Gd, 5; HL = 4-allyl-2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol; Py = pyridine), a series of metallopolymers Poly(NBE-co-[Zn(L)2Ln(Py)(NO3)3)]) were obtained, respectively. Especially for Poly(NBE-co-2) and Poly(NBE-co-3), covalently-bonded grafting endows significantly improved physical properties including efficient NIR luminescence (ΦNdL = 0.63% and ΦYbL = 1.43%) in solid state.

  2. Spectroscopic properties of KGd(WO{sub 4}){sub 2} single crystals doped with Er{sup 3+}, Ho{sup 3+}, Tm{sup 3+} and Yb{sup 3+} ions: Luminescence and micro-Raman investigations

    Energy Technology Data Exchange (ETDEWEB)

    Kasprowicz, D., E-mail: Dobroslawa.Kasprowicz@put.poznan.pl [Faculty of Technical Physics, Poznan University of Technology, Nieszawska 13 A, 60-965 Poznan (Poland); Brik, M.G. [Institute of Physics, University of Tartu, Riia 142, Tartu 51014 (Estonia); Majchrowski, A. [Institute of Applied Physics, Military University of Technology, Kaliskiego 2, 00-908 Warszawa (Poland); Michalski, E. [Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warszawa (Poland); Głuchowski, P. [Institute of Low Temperature and Structure Research of Polish Academy of Sciences, Okólna 2, 50-422 Wroclaw (Poland)

    2013-11-15

    Highlights: •Investigations of KGd(WO{sub 4}){sub 2} crystals doped with Ho/Yb/Er and Ho/Tm/Yb/Er ions. •The vibrational properties were studied using micro-Raman spectroscopy. •The multicolor up-converted luminescence was investigated. -- Abstract: KGd(WO{sub 4}){sub 2} single crystals doped with Ho{sup 3+}/Yb{sup 3+}/Er{sup 3+} and Ho{sup 3+}/Tm{sup 3+}/Yb{sup 3+}/Er{sup 3+} ions were grown by means of the Top Seeded Solution Growth (TSSG) method. It was shown that these systems exhibit multicolor up-conversion luminescence in the visible and near-infrared spectral ranges under 980 nm laser excitation. In the investigated crystals the Yb{sup 3+} ions were used as the energy sensitizer ion and the up-converted luminescence originates from transitions between the energy levels of other co-doped rare earth ions such as Er{sup 3+}, Ho{sup 3+} or Tm{sup 3+}, which play the role of the energy activator ions. The vibrational properties of the crystals were investigated using micro-Raman spectroscopy and the role of vibrational energy in the effective energy transfer process between the rare earth ions was discussed. The proposed combinations of activator ions may be suitable for gaining novel materials with effective green, red and near-infrared emission.

  3. Enhancement of Visible Upconversion Emission in Y2O3:Er3+-Yb3+ by Addition of Thiourea and LiOH in the Phosphor Synthesis

    Directory of Open Access Journals (Sweden)

    Eder Resendiz-L

    2015-01-01

    Full Text Available Spherical like Y2O3 nanostructures doped with Er3+ and Yb3+ ions have been synthesized by a facile hydrothermal method. The samples were prepared by using different precipitant agents in the synthesis process. The phosphors were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, and photoluminescence spectroscopy. Effects of the precipitant agents on structural, morphological, and photoluminescence properties of Y2O3:Er3+-Yb3+ are studied and discussed. XRD analysis indicates that all samples, prepared with different precipitant agents, present the same cubic phase. Electron microscopy measurements show regular spherical shapes with size diameter depending on precipitant agent. Photoluminescence reveals that the samples have strong green (563 nm and red (660 nm emissions corresponding to 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. The nanophosphors prepared with both Thiourea and Lithium Hydroxide exhibit the stronger visible upconversion luminescence under 980 nm diode laser excitation.

  4. Synthesis of NaLuF4:Er3+, Yb3+, Ce3+ nanoparticles and study of photoluminescent properties in C - band

    Directory of Open Access Journals (Sweden)

    Khaydukov K.V.

    2017-01-01

    Full Text Available The novel core@shell nanocrystals β-NaLuF4@NaLuF4 co-doped with rare-earth ions Er3+, Yb3+, Ce3+ have been synthesized. The nano-particles indicate the intensive lines of anti-Stokes luminescence in the telecommunication С - band of spectrum when pumped at 970-980 nm. The nanoparticles have been characterized by transmission electron microscopy and spectrofluorimetry. The nanoparticles have a size 40-80 nm and possess the intensive photo-luminescence 73 nm bandwidth centered around 1530 nm. The photo-luminescence kinetics of β-NaLuF4: Er3+/ Yb3+/ Ce3+ has been studied in IR range of spectrum. We have demonstrated that doping with cerium ions prevents serial stepwise excitation of erbium ions. Consequently, the lifetime of transition in erbium 4I13/2→4I15/2 has risen up to 6.9 ms. Intensity of 1530 nm line in Er3+ ions excited at 980 nm has been increased up to 6 times. Therefore, the nanoparticles are applicable to fabrication of compact waveguide amplifiers for C - band.

  5. Optical Temperature Sensing Behavior Through Stark Sublevels Transitions of Green and Red Upconversion Emissions for Er3+-Yb3+-Li+ Codoped TiO2 Phosphors.

    Science.gov (United States)

    He, Y Y; Wu, J L; Wang, X H; Feng, Z Q; Dong, B

    2016-04-01

    The Er3+-Yb3+-Li+ codoped TiO2 phosphors have been prepared by sol-gel method. The green and red upconversion emissions were observed under a 976 nm laser diode excitation, which were ascribed to 2H11/2 --> 4I15/2, 4S3/2(I)/4S3/2(II) -->4I15/2, and 4F9/2(I)/4F9/2(II) -->4I15/2 transitions of Er3+ Stark sublevels. The fluorescence intensity ratios (FIR), which are corresponding to the transitions of 2H11/2/(4S3/2(I)+4S3/2(II))--> 4I5/2, 4S3/2(I)/4S3/2(II) -->4I15/2, and 4F9/2(II)/4F9/2(II) -->4I15/2, have been studied as a function of temperature in the range of 303 673 K. The temperature sensitivities have been calculated at the maximum value of 0.0020 K-1, 0.0015 K-1, and 0.0011 K-1 at the temperatures of 427 K, 350 K, and 273 K for the three coupled energy level transitions, respectively. The Er3+-Yb3+-Li+ codoped Ti02 phosphor with different temperature sensitivities by Stark sublevels indicated that it is a promising material for application in optical temperature sensing at a wide range of temperature.

  6. Highly matched spectrum needed for photosynthesis in Ce{sup 3+}/Er{sup 3+}/Yb{sup 3+} tri-doped oxyfluoride glass ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Weirong; Gao, Huiping [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute for Computational Materials Science, Henan University, Kaifeng 475004 (China); Mao, Yanli, E-mail: ylmao@henu.edu.cn [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute for Computational Materials Science, Henan University, Kaifeng 475004 (China)

    2015-11-05

    A series of oxyfluoride glass ceramics containing CaF{sub 2} nano-crystals tri-doped with Ce{sup 3+}/Er{sup 3+}/Yb{sup 3+} ions were prepared by high temperature melting method and subsequent heat treatment. The structural properties were examined by X-ray diffraction measurements. The absorption, excitation, and emission spectra of the glass ceramics were investigated. Difference in erbium emission spectra between glass and glass ceramics had been studied. The emission bands originating from the {sup 4}F{sub 9/2} state of Er{sup 3+} were enhanced when the CaF{sub 2} nano-crystal created. By down-converting the ultraviolet wavelength region (280∼400 nm) light and up-converting the near-infrared wavelength region (900∼1100 nm) light, the glass ceramics can also emit strong reddish orange emission. The emission spectra consisting of bluish violet (400∼500 nm) and reddish orange (640∼680 nm) bands match well with the action spectrum of photosynthesis and absorption spectra of chlorophylls. Our materials will be favored to promote the development of glass greenhouses for green plant. - Highlights: • Ce{sup 3+}/Er{sup 3+}/Yb{sup 3+} tri-doped oxyfluoride glass ceramics were prepared by high temperature melting method. • 668 nm red emission was obtained under 320 nm, 380 nm and 980 nm excitation, respectively. • The emission of samples matched well with the spectrum for photosynthesis.

  7. A facile synthesis approach and impact of shell formation on morphological structure and luminescent properties of aqueous dispersible NaGdF4:Yb/Er upconversion nanorods

    Science.gov (United States)

    Ansari, Anees A.; Yadav, Ranvijay; Rai, S. B.

    2016-12-01

    A general facile synthesis approach was used for fabrication of highly emissive aqueous dispersible hexagonal phase upconversion luminescent NaGdF4:Yb/Er nanorods (core NRs) through metal complex decomposition process. An inert NaGdF4 and porous silica layers were grafted surrounding the surface of each and every NRs to enhance their luminescence efficiency and colloidal dispersibility in aqueous environment. Optical properties in terms of band gap energy of core, core/shell, and silica-coated core/shell/SiO2 nanorods were observed to investigate the influence of surface coating, which was gradually decreased after surface coating because of increase crystalline size after growth of inert and silica shells. The inert shell formation before silica surface grafting, upconversion luminescence intensity was greatly improved by about 20 times, owing to the effective surface passivation of the seed core and, therefore, protection of Er3+ ion in the core from the nonradiative decay caused by surface defects. Moreover, after silica coating, core/shell nanorods shows strong upconversion luminescence property similar to the hexagonal upconversion core NRs. It is expected that these NaGdF4:Yb/Er@NaGdF4@SiO2 (core/shell/SiO2) NRs including highly upconversion emissive and aqueous dispersible properties make them an ideal materials for various photonic-based potential applications such as in upconversion luminescent bioimaging, magnetic resonance imaging, and photodynamic therapy.

  8. Magnetic/upconversion fluorescent NaGdF4:Yb,Er nanoparticle-based dual-modal molecular probes for imaging tiny tumors in vivo.

    Science.gov (United States)

    Liu, Chunyan; Gao, Zhenyu; Zeng, Jianfeng; Hou, Yi; Fang, Fang; Li, Yilin; Qiao, Ruirui; Shen, Lin; Lei, Hao; Yang, Wensheng; Gao, Mingyuan

    2013-08-27

    Detection of early malignant tumors remains clinically difficult; developing ultrasensitive imaging agents is therefore highly demanded. Owing to the unusual magnetic and optical properties associated with f-electrons, rare-earth elements are very suitable for creating functional materials potentially useful for tumor imaging. Nanometer-sized particles offer such a platform with which versatile unique properties of the rare-earth elements can be integrated. Yet the development of rare-earth nanoparticle-based tumor probes suitable for imaging tiny tumors in vivo remains difficult, which challenges not only the physical properties of the nanoparticles but also the rationality of the probe design. Here we report new approaches for size control synthesis of magnetic/upconversion fluorescent NaGdF4:Yb,Er nanocrystals and their applications for imaging tiny tumors in vivo. By independently varying F(-):Ln(3+) and Na(+):Ln(3+) ratios, the size and shape regulation mechanisms were investigated. By replacing the oleic acid ligand with PEG2000 bearing a maleimide group at one end and two phosphate groups at the other end, PEGylated NaGdF4:Yb,Er nanoparticles with optimized size and upconversion fluorescence were obtained. Accordingly, a dual-modality molecular tumor probe was prepared, as a proof of concept, by covalently attaching antitumor antibody to PEGylated NaGdF4:Yb,Er nanoparticles through a "click" reaction. Systematic investigations on tumor detections, through magnetic resonance imaging and upconversion fluorescence imaging, were carried out to image intraperitoneal tumors and subcutaneous tumors in vivo. Owing to the excellent properties of the molecular probes, tumors smaller than 2 mm was successfully imaged in vivo. In addition, pharmacokinetic studies on differently sized particles were performed to disclose the particle size dependent biodistributions and elimination pathways.

  9. NaYF4:Er(3+),Yb(3+)/SiO2 Core/Shell Upconverting Nanocrystals for Luminescence Thermometry up to 900 K.

    Science.gov (United States)

    Geitenbeek, Robin G; Prins, P Tim; Albrecht, Wiebke; van Blaaderen, Alfons; Weckhuysen, Bert M; Meijerink, Andries

    2017-02-16

    The rapid development of nanomaterials with unique size-tunable properties forms the basis for a variety of new applications, including temperature sensing. Luminescent nanoparticles (NPs) have demonstrated potential as sensitive nanothermometers, especially in biological systems. Their small size offers the possibility of mapping temperature profiles with high spatial resolution. The temperature range is however limited, which prevents use in high-temperature applications such as, for example, nanoelectronics, thermal barrier coatings, and chemical reactors. In this work, we extend the temperature range for nanothermometry beyond 900 K using silica-coated NaYF4 nanoparticles doped with the lanthanide ions Yb(3+) and Er(3+). Monodisperse ∼20 nm NaYF4:Yb,Er nanocrystals were coated with a ∼10 nm silica shell. Upon excitation with infrared radiation, bright green upconversion (UC) emission is observed. From the intensity ratio between (2)H11/2 and (4)S3/2 UC emission lines at 520 and 550 nm, respectively, the temperature can be determined up to at least 900 K with an accuracy of 1-5 K for silica-coated NPs. For bare NaYF4:Yb,Er NPs, the particles degrade above 600 K. Repeated thermal cycling experiments demonstrate the high durability and reproducibility of the silica-coated nanocrystals as temperature probes without any loss of performance. The present results open avenues for the development of a new class of highly stable nanoprobes by applying a silica coating around a wide variety of lanthanide-doped NPs.

  10. NaYF4:Er3+,Yb3+/SiO2 Core/Shell Upconverting Nanocrystals for Luminescence Thermometry up to 900 K

    Science.gov (United States)

    2017-01-01

    The rapid development of nanomaterials with unique size-tunable properties forms the basis for a variety of new applications, including temperature sensing. Luminescent nanoparticles (NPs) have demonstrated potential as sensitive nanothermometers, especially in biological systems. Their small size offers the possibility of mapping temperature profiles with high spatial resolution. The temperature range is however limited, which prevents use in high-temperature applications such as, for example, nanoelectronics, thermal barrier coatings, and chemical reactors. In this work, we extend the temperature range for nanothermometry beyond 900 K using silica-coated NaYF4 nanoparticles doped with the lanthanide ions Yb3+ and Er3+. Monodisperse ∼20 nm NaYF4:Yb,Er nanocrystals were coated with a ∼10 nm silica shell. Upon excitation with infrared radiation, bright green upconversion (UC) emission is observed. From the intensity ratio between 2H11/2 and 4S3/2 UC emission lines at 520 and 550 nm, respectively, the temperature can be determined up to at least 900 K with an accuracy of 1–5 K for silica-coated NPs. For bare NaYF4:Yb,Er NPs, the particles degrade above 600 K. Repeated thermal cycling experiments demonstrate the high durability and reproducibility of the silica-coated nanocrystals as temperature probes without any loss of performance. The present results open avenues for the development of a new class of highly stable nanoprobes by applying a silica coating around a wide variety of lanthanide-doped NPs. PMID:28303168

  11. Spectral-converting study of La{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m=0.001–0.2, n=0–0.1) phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

    2014-09-15

    Optical materials composed of La{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m=0.001–0.2, n=0–0.1) solid solution were prepared via a solid-state reaction using excess NH{sub 4}Cl flux at 950 °C for 30 min. X-ray diffraction patterns of La{sub 1−m}Er{sub m}OCl were compared upon altering the molar ratios of the flux to the La{sup 3+} (Er{sup 3+}, Yb{sup 3+}) ions. By means of photoluminescence spectra, the dependence of the luminescence intensity as a function of the Er{sup 3+} content and the color CIE coordinates of the Er{sup 3+}-doped layered LaOCl compounds were also investigated under excitation by near-ultraviolet (NUV) and visible light. The spectral conversion properties of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} ions doped into LaOCl phosphors were elucidated under diode-laser irradiation of 980 nm in wavelength. The desired up-conversion of the emitting light, passing throughout the green, orange, and red regions of the spectrum, was achieved by appropriate Er{sup 3+} and/or Yb{sup 3+} concentrations in the LaOCl host structure under 980-nm-excitation light, while its mechanism in the phosphors was described by an energy-level schematic. Up-conversion emission spectra and the dependence of the emission intensity on pump power in the La{sub 0.89}Er{sub 0.1}Yb{sub 0.01}OCl phosphor were investigated under diode-laser irradiation of both wavelengths, 980 and 1550 nm. - Highlights: • Flux-assisted La{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m=0.001–0.2, n=0–0.1) phosphors were prepared. • Distinctive photoluminescence properties of Er{sup 3+}-doped LaOCl were investigated. • Spectral converting properties of Er{sup 3+} and Yb{sup 3+} in LaOCl phosphors were elucidated. • Up-conversion mechanisms are proposed on the basis of an energy-level diagram. • Dependence of the emission intensity on pump power in the phosphor was investigated.

  12. Up-conversion routines of Er{sup 3+}–Yb{sup 3+} doped Y{sub 6}O{sub 5}F{sub 8} and YOF phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Yang, Wonseok; Park, Chu-Young; Noh, Minhee; Choi, Seulki [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Park, Dahye; Jang, Ho Seong; Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

    2015-11-15

    Highlights: • Single-phase optical materials of Y{sub 6}O{sub 5}F{sub 8}:Er and YOF:Er were prepared. • Effective spectral converting properties were observed in Y{sub 6}O{sub 5}F{sub 8}:Er,Yb. • 980 nm diode laser was irradiated for up-converting analysis. • A multi-photon process in the phosphors was investigated. - Abstract: Optical materials composed of a Y{sub 6(1−p−q)}Er{sub 6p}Yb{sub 6q}O{sub 5}F{sub 8} (p = 0.001–0.1, q = 0.005–0.1) solid solution with Y{sub 0.99}Er{sub 0.01}OF were prepared via a solid-state reaction using excess NH{sub 4}F flux at 950 °C for 30 min. X-ray diffraction patterns of Y{sub 6(1−p−q)}Er{sub 6p}Yb{sub 6q}O{sub 5}F{sub 8} and Y{sub 0.99}Er{sub 0.01}OF were compared upon altering the synthesis temperature and the molar ratio of the NH{sub 4}F flux to the Y{sup 3+} (Er{sup 3+}, Yb{sup 3+}) ions. The effective spectral-conversion properties of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} ions in Y{sub 6}O{sub 5}F{sub 8} phosphors were monitored during excitation with a 980 nm wavelength diode-laser. Selection of appropriate Er{sup 3+} and/or Yb{sup 3+} concentrations in the Y{sub 6}O{sub 5}F{sub 8} structure led to achievement of the desired up-conversion emission, from the green to the red regions of the spectra. Furthermore, the mechanism of up-conversion in the phosphors was described by an energy-level schematic. Up-conversion emission spectra and the dependence of the emission intensity on pump power (between 193 and 310 mW) in the Y{sub 6(0.995−q)}Er{sub 0.03}Yb{sub 6q}O{sub 5}F{sub 8} phosphors were also investigated.

  13. Cytotoxic interactions of bare and coated NaGdF4:Yb(3+):Er(3+) nanoparticles with macrophage and fibroblast cells.

    Science.gov (United States)

    Wysokińska, E; Cichos, J; Zioło, E; Bednarkiewicz, A; Strządała, L; Karbowiak, M; Hreniak, D; Kałas, W

    2016-04-01

    The lanthanide nano-compounds are well suited to serve as fluorescent and magnetic contrast agents and luminescent labels. Although they are considered as promising materials for bio-imaging and bio-sensors in vivo or in vitro, the amount of data is still insufficient for deep understanding the toxicity of these nanomaterials. This knowledge is of great importance in the light of growing use of the biofunctionalized nanoparticles, which raises some questions about safety of these materials. Despite lanthanide-doped NaGdF4 nanocrystals are considered as non-toxic, here we present the data showing the fatal effect of newly synthetized NaGdF4:Yb(3+):Er(3+) on chosen types of cells. Our studies were performed on two cell lines NIH3T3 fibroblasts, and RAW264.7 macrophages. Cytotoxic properties of NaGdF4:Yb(3+):Er(3+) nanoparticles and their biological effects were studied by assessing cell culture viability (MTS), proliferation and apoptosis. Bare NaGdF4:Yb(3+):Er(3+) nanocrystals were cytotoxic and induced apoptosis of both NIH3T3 and RAW264.7 cells. Their cytotoxicity was reduced by PEGylation, at the expense of minimizing direct interactions between the compound and the cell. On the other hand, coating with silica reduced cell death induced by Yb(3+):Er(3+) codoped NaGdF4 nanocrystals (but proliferation was still inhibited). The NH2-modified silica coated nanoparticles were clearly less cytotoxic than pristine nanoparticles, which suggests that both, silica and PEG coatings are reasonable approaches to decrease cytotoxicity of the nanocrystal labels. The silica and PEG shell, should also enable and simplify further bio-functionalization of these luminescent labels. The authors acknowledge the financial support from: Institute of Immunology and Experimental Therapy, Polish Academy of Sciences (IITD PAN) grant no. 3/15, Polish Ministry of Science and Higher Education, Grant N N507 499538 and from the Wroclaw Research Centre EIT+ within the project "The Application of

  14. NaYF4:Yb/Er@PPy core-shell nanoplates: an imaging-guided multimodal platform for photothermal therapy of cancers

    Science.gov (United States)

    Huang, Xiaojuan; Li, Bo; Peng, Chen; Song, Guosheng; Peng, Yuxuan; Xiao, Zhiyin; Liu, Xijian; Yang, Jianmao; Yu, Li; Hu, Junqing

    2015-12-01

    Imaging guided photothermal agents have attracted great attention for accurate diagnosis and treatment of tumors. Herein, multifunctional NaYF4:Yb/Er@polypyrrole (PPy) core-shell nanoplates are developed by combining a thermal decomposition reaction and a chemical oxidative polymerization reaction. Within such a composite nanomaterial, the core of the NaYF4:Yb/Er nanoplate can serve as an efficient nanoprobe for upconversion luminescence (UCL)/X-ray computed tomography (CT) dual-modal imaging, the shell of the PPy shows strong near infrared (NIR) region absorption and makes it effective in photothermal ablation of cancer cells and infrared thermal imaging in vivo. Thus, this platform can be simultaneously used for cancer diagnosis and photothermal therapy, and compensates for the deficiencies of individual imaging modalities and satisfies the higher requirements on the efficiency and accuracy for diagnosis and therapy of cancer. The results further provide some insight into the exploration of multifunctional nanocomposites in the photothermal theragnosis therapy of cancers.Imaging guided photothermal agents have attracted great attention for accurate diagnosis and treatment of tumors. Herein, multifunctional NaYF4:Yb/Er@polypyrrole (PPy) core-shell nanoplates are developed by combining a thermal decomposition reaction and a chemical oxidative polymerization reaction. Within such a composite nanomaterial, the core of the NaYF4:Yb/Er nanoplate can serve as an efficient nanoprobe for upconversion luminescence (UCL)/X-ray computed tomography (CT) dual-modal imaging, the shell of the PPy shows strong near infrared (NIR) region absorption and makes it effective in photothermal ablation of cancer cells and infrared thermal imaging in vivo. Thus, this platform can be simultaneously used for cancer diagnosis and photothermal therapy, and compensates for the deficiencies of individual imaging modalities and satisfies the higher requirements on the efficiency and accuracy for

  15. Widely tunable, narrow line width and low optical noise continuous-wave all fiber Er:Yb co-doped double-clad ring laser

    Science.gov (United States)

    Guesmi, Khmaies; Bahloul, Faouzi; Semaan, Georges; Meng, Yichang; Salhi, Mohamed; Sanchez, François

    2017-01-01

    In this paper, we report a widely tunable, narrow linewidth, low noise continuous-wave double-clad Er:Yb doped fiber ring laser. Tunability is demonstrated in wide range spanning from 1520 to almost 1620 nm covering the C and L spectral bands. The cavity design is optimized in order to achieve the largest tuning range with very high optical signal-to-noise ratio (SNR). The output coupling ratio greatly influences the tuning range of the laser while the position of the spectral filter determines the SNR. The obtained laser exhibits a tuning range over 98 nm with a nearly constant SNR of about 58.5 dB.

  16. Standard energies of combustion and standard enthalpies of formation for the complexes RE (Et2dtc)3(phen) (RE=Ho, Er, Tm, Yb, Lu)

    Institute of Scientific and Technical Information of China (English)

    WEI Qing; CHEN Sanping; YANG Xuwu; GAO Shengli; SHI Qizhen

    2005-01-01

    The treatment of RECl3·xH2O (RE = Ho, Er, Tm, Yb, Lu; x = 3-4) with sodium diethyldithiocarbamate RE(Et2dtc)3(phen). IR spectra of the complexes showed that RE3+ coordinated to two sulfur atoms in NaEt2dtc and two ritrogen atoms in o-phen. The constant-volume energies of combustion of the complexes have been determined by a precise rotating-bomb calorimeter at 298.15 K. The standard enthalpies of combustion and standard enthalpies of formation were calculated.

  17. Effects of Er{sup 3+} and Yb{sup 3+} doping on structural and non-linear optical properties of LiNaSO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Palmero, I.C. [Departamento de Fisica Basica, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Gonzalez-Silgo, C. [Departamento de Fisica Fundamental II, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Torres, M.E. [Departamento de Fisica Basica, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Marrero-Lopez, D. [Departamento de Quimica Inorganica, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Rivera-Lopez, Fernando [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain)], E-mail: frivera@ull.es; Haro-Gonzalez, P. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Solans, X. [Departament de Cristallografia, Universitat de Barcelona, E-08028, Barcelona (Spain)

    2008-05-15

    We have characterized LiNaSO{sub 4} crystals doped with rare earth (RE) (Er{sup 3+} and Yb{sup 3+}) to give new insights about their structural properties relations. The samples were analyzed by X-ray single crystal diffraction and differential thermal analysis. The non-centrosymmetry was confirmed second-harmonic generation. Inductively coupled plasma (ICP) and emission experiments confirmed the nominal concentrations of the REs. Crystallographic data and two empirical models were employed to understand the structural modifications by substitution of the Na site which reduces, monotonically, the non-linear optical coefficients and the temperature of the phase transition in these crystals.

  18. Effect of Gallium and Indium Co-Substituting on Upconversion Properties of Er/Yb:Yttrium Aluminum Garnet Powders Prepared by the Co-Precipitation Method.

    Science.gov (United States)

    Zhang, Wei; Liang, Yun-Ling; Hu, Zheng-Fa; Feng, Zu-Yong; Lun, Ma; Zhang, Xiu-ping; Sheng, Xia; Liu, Qian; Luo, Jie

    2016-04-01

    Gallium and Indium co-substituted Yb, Er:YAG was fabricated through the chemical co-precipitation method. The formation process and structure of the Ga3+ and In3+ substituted phosphor powders were characterized by the X-ray diffraction, thermo-gravimetry analyzer, infrared spectra, and X-ray photoelectron spectroscopy, and the effects of Ga3+ and In3+ concentration on the luminescence properties were investigated by spectrum. The results showed that the blue shift occurred after the substitution of Ga3+ and In3+ for Al3+ in matrix, and the intensity of emission spectrum was affected by the concentration of Ga3+ and In3+.

  19. Thermal analysis of a diffusion bonded Er3+,Yb3+:glass/Co2+: MgAl2O4 microchip lasers

    Science.gov (United States)

    Belghachem, Nabil; Mlynczak, Jaroslaw; Kopczynski, krzysztof; Mierczyk, Zygmunt; Gawron, Michal

    2016-10-01

    The analysis of thermal effects in a diffusion bonded Er3+,Yb3+:glass/Co2+:MgAl2O4 microchip laser is presented. The analysis is performed for both wavelengths at 940 nm and at 975 nm as well as for two different sides of pumping, glass side and saturable absorber side. The heat sink effect of Co2+:MgAl2O4, as well as the impact of the thermal expansion and induced stress on the diffusion bonding are emphasised. The best configurations for reducing the temperature peaks, the Von Mises stresses on the diffusion bonding, and the thermal lensing are determined.

  20. Jahn-Teller distortion and magnetic transitions in perovskite RMnO3 ( R=Ho , Er, Tm, Yb, and Lu)

    Science.gov (United States)

    Tachibana, Makoto; Shimoyama, Tomotaka; Kawaji, Hitoshi; Atake, Tooru; Takayama-Muromachi, Eiji

    2007-04-01

    The perovskite RMnO3 ( R=Ho , Er, Tm, Yb, and Lu) were prepared under high pressure and studied with heat capacity and synchrotron x-ray powder diffraction measurements. The temperature interval between the antiferromagnetic transition and the first-order transition to the presumably E -type structure narrows with the decreasing ionic radius of R , and almost closes for R=Lu . Combined with the data for the larger rare earth R , the results show intricate relationship between the complex magnetic phase diagram and significant increase of Jahn-Teller distortion found for the smallest members of RMnO3 .

  1. Synthesis of stable carboxy-terminated NaYF4: Yb3+, Er3+@SiO2 nanoparticles with ultrathin shell for biolabeling applications

    Science.gov (United States)

    Liu, Fuyao; Zhao, Qi; You, Hongpeng; Wang, Zhenxin

    2013-01-01

    Here, a two-step method has been developed for synthesizing carboxy-terminated NaYF4: Yb3+, Er3+@SiO2 core@shell nanoparticles (UCNP@SiO2) with ultrathin shell (1.5 nm). First, the NaYF4: Yb3+, Er3+ upconverting nanoparticles (UCNPs) were prepared using solvothermal technology; then, silica shells (SiO2) were deposited on the nanocrystals to form core-shell structures by the hydrolysis of tetraethylorthosilicate (TEOS). The ultrathin SiO2 shell was obtained by increasing surfactant amount and decreasing TEOS amount in the reaction mixture. Carboxyethylsilanetriol (CTES) was used to generate the carboxy group on the particle surface. The carboxy-terminated UCNP@SiO2 are ideally suited for biolabeling and bioimaging applications because the as-prepared nanoparticles have extreme colloidal and optical stabilities, and the carboxy groups on the particle surface easily react with amino residues of biomolecules. As an example, we reported on the interactions of Ricinus Communis Agglutinin (RCA 120) conjugated UCNP@SiO2 with HeLa cells. The excellent performance of the RCA 120 conjugated UCNP@SiO2 in cellular fluorescence imaging was demonstrated.Here, a two-step method has been developed for synthesizing carboxy-terminated NaYF4: Yb3+, Er3+@SiO2 core@shell nanoparticles (UCNP@SiO2) with ultrathin shell (1.5 nm). First, the NaYF4: Yb3+, Er3+ upconverting nanoparticles (UCNPs) were prepared using solvothermal technology; then, silica shells (SiO2) were deposited on the nanocrystals to form core-shell structures by the hydrolysis of tetraethylorthosilicate (TEOS). The ultrathin SiO2 shell was obtained by increasing surfactant amount and decreasing TEOS amount in the reaction mixture. Carboxyethylsilanetriol (CTES) was used to generate the carboxy group on the particle surface. The carboxy-terminated UCNP@SiO2 are ideally suited for biolabeling and bioimaging applications because the as-prepared nanoparticles have extreme colloidal and optical stabilities, and the carboxy

  2. Li+共掺杂对Er3+-Yb3+:TiO2紫外、可见和红外发光同步增强研究%Simultaneous Enhanced Ultraviolet, Visible and Infrared Emissions in Er3+-Yb3+:TiO2 by Li+ Codoping

    Institute of Scientific and Technical Information of China (English)

    曹保胜; 何洋洋; 冯志庆; 宋苗; 董斌

    2011-01-01

    采用溶胶-凝胶(Sol-gel)法制备了Li+共掺杂的Er3+-Yb3+:TiO2粉末.976 nm激光激发下在波长350~1700nm范围内观察到了紫外、蓝色、绿色和红色上转换发光和红外下转换发光.随着Li+共掺杂浓度由0增大到20mol%,Er3+-Yb3+:TiO2的紫外、可见和红外发光强度同步增强.低Li+共掺杂浓度引起的Li+固溶以及高Li+共掺杂浓度引起的相变过程相继破坏了Er3+的晶体场对称性,导致紫外、可见和红外发光显著增强.结果表明共掺杂Li+是一种提高Er3+掺杂材料发光性能的有效方法.%The Er3+-Yb3+:TiO2 powders by Li+ codoping have been prepared by sol-gel method. Both uhraviolet, blue,green and red upconversion and infrared downconversion emissions in the wavelengths of 350-1700 nm were observed by a 976 nm semiconductor laser diode (LD) excitation. The ultraviolet, visible and infrared emissions of Er3 +-Yb3 +:TiO2 enhanced simultaneously by increasing Li+ from 0 to 20mol%. The significant enhancement of ultraviolet, visible and infrared emissions resulted from the distortion of crystal field symmetry of Er3+ caused by the dissolving of Li+ at lower Li+ codoping concentration and the phase transformation at higher Li+ concentration. It can be concluded that codoping with Li+ is an efficient method to enhance the luminescence of Er3+ doped materials.

  3. Enhancement of the photovoltaic performance of dye-sensitized solar cells by doping Y{sub 0.78}Yb{sub 0.20}Er{sub 0.02}F{sub 3} in the photoanode

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jihuai; Wang, Jiangli; Lin, Jianming; Lan, Zhang; Tang, Qunwei; Huang, Miaoliang; Huang, Yunfang; Fan, Leqing; Li, Qingbei; Tang, Ziying [Institute of Materials Physical Chemistry, Huaqiao University, Quanzhou (China)

    2012-01-15

    Y{sub 0.78}Yb{sub 0.20}Er{sub 0.02}F{sub 3} is introduced into the TiO{sub 2} photoanode in a dye-sensitized solar cell (DSSC). Y{sub 0.78}Yb{sub 0.20}Er{sub 0.02}F{sub 3} improves infrared light harvesting via up-conversion luminescence and thus increases the photocurrent. Yb{sup 3+}/Er{sup 3+} elevates the energy level of the TiO{sub 2} electrode and thus increases the photovoltage. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Facile fabrication and upconversion luminescence enhancement of LaF3:Yb3+/Ln3+@SiO2 (Ln = Er, Tm) nanostructures decorated with Ag nanoparticles.

    Science.gov (United States)

    He, Enjie; Zheng, Hairong; Dong, Jun; Gao, Wei; Han, Qingyan; Li, Junna; Hui, Le; Lu, Ying; Tian, Huani

    2014-01-31

    A novel hybrid nanostructure, that is a Ag nanoparticle decorated LaF(3):Yb(3+)/Ln(3+)@SiO(2) nanosphere (Ln=Er, Tm), was constructed by a facile strategy, and characterized by XRD, TEM, FTIR, XPS and UV-vis-NIR absorption. Obvious spectral broadening and red-shift on the surface plasmon resonance were obtained by adjusting the size and configuration of Ag nanoparticles. Effective upconversion luminescence enhancements for Er(3+) and Tm(3+) containing samples were obtained. It is suggested that the luminescence enhancement results from both the excitation and emission processes, and the configuration of the studied hybrid nanostructure is an efficient system to enhance the luminescence emission of rare earth doped nanomaterials. It is believed that the enhancement from the hybrid nanostructure will find great potential in the development of photovoltaic solar cells.

  5. Structural, magnetic and electronic transport studies of RAgSn2 compounds (R = Y, Tb, Dy, Ho and Er) with Cu3Au-type

    Indian Academy of Sciences (India)

    L Romaka; V V Romaka; I Lototska; A Szytula; B Kuzhel; A Zarzycki; E K Hlil; D Fruchart

    2013-12-01

    RAgSn2 compounds, where R = Y, Tb, Dy, Ho and Er, were synthesized by arc-melting and subsequent annealing at 870 K. The formation of cubic phases with Cu3Au-type structure (space group $\\bar{3}$) was studied. Magnetic property measurements showed that in paramagnetic state, the compounds with magnetic rareearth atoms are Curie–Weiss paramagnets and order antiferromagnetically at low temperatures. YAgSn2 is a Pauli paramagnet in 100–300 K temperature range. The electrical properties of RAgSn2 compounds were investigated by means of electrical resistivity and Seebeck coefficient measurements in 4.2–300 K temperature range. All investigated compounds exhibit metallic type of conductivity. Electronic structure calculations based on full potential linearized augmented plane wave (FLAPW)method is also carried out to probe themagnetic and electronic structures of RAgSn2 compounds. Comparisons between experimental data and calculations are discussed.

  6. Full potential calculations and atom in molecule analysis of the bonding properties of perovskites Borides XRh3B (X=Dy, Ho, Er

    Directory of Open Access Journals (Sweden)

    Ouahrani T.

    2013-03-01

    Full Text Available ab initio calculations were performed for the cubic perovskites Borides XRh3B, (X=Dy, Ho, Er. In this work, we have used the augmented plane-wave plus local orbital method to compute the equilibrium structural parameters and electronic structure of densities of states, as well as for the first time, prediction of the thermo-elastic properties of these crystals are presented. The chemical bonding of these compounds has been investigated by using of topological analyses grounded in the theory of atoms in molecules (AIM. All of the electron density critical points in the unit cell were systematically calculated in order to calculate basins interaction of each atoms and give exact classification of the bonding character.

  7. New Materials Derived from Ybco: CrSr2RECu2O8 (RE = La, Pr, Nd, Eu, Gd, Tb, Dy, Y, Ho, Er, Lu).

    Science.gov (United States)

    Ruiz-Bustos, Rocío; Aguirre, Myriam H; Alario-Franco, Miguel A

    2005-05-02

    Eleven new oxides, derived from yttrium barium copper oxide by replacing the square-planar copper [Cu-O4] of the basal plane of the triple perovskite-based structure with octahedral Cr(IV), have been prepared at high pressure and temperature. Their crystal structures have been determined, and their complex microstructure has been established by means of high-resolution electron microscopy and electron diffraction. The materials have a general formula of CrSr2RECu2O8 (RE = La, Pr, Nd, Eu, Gd, Tb, Dy, Y, Ho, Er, and Lu); they are tetragonal, show the symmetry of space group P4/mmm, and do not appear to be superconducting.

  8. Heat capacities, magnetic properties, and resistivities of ternary RPdBi alloys where R = La, Nd, Gd, Dy, Er, and Lu

    Energy Technology Data Exchange (ETDEWEB)

    Riedemann, T.M.

    1996-05-01

    Over the past four and a half decades research on the rare earths, their compounds, and their alloys has yielded significant insights into the nature of materials. The rare earths can be used to systematically study a series of alloys or compounds. Magnetic ordering, crystalline fields, spin fluctuations, the magnetocaloric effect, and magnetostriction are a small sample of phenomena studied that are exhibited by the rare earth family. A significant portion of research has been conducted on the abundant RM{sub 2} and RM phases, where R is the rare earth and M is a transition metal. The natural progression of science has led to the study of related RMX ternary phases, where X is either another transition metal or semimetal. There are now over 1,000 known RMX phases. The focus of this study is on RPdBi where R = La, Nd, Gd, Dy, Er, and Lu. Their heat capacities, magnetic properties, and resistivities are studied.

  9. Enhanced 2.7 μm mid-infrared emissions of Er3+ via Pr3+ deactivation and Yb3+ sensitization in LiNbOsub>3sub> crystal.

    Science.gov (United States)

    Zhang, Peixiong; Chen, Zhenqiang; Hang, Yin; Li, Zhen; Yin, Hao; Zhu, Siqi; Fu, Shenhe; Li, Anming

    2016-10-31

    The use of Pr3+ codoping for enhancement of the transition of Er3+: 4Isub>11/2sub> → 4Isub>13/2sub> 2.7 μm emissions was investigated in the Er/Yb codoped LiNbOsub>3sub> crystal for the first time. It is found that the codoped of Pr3+ ion in Er3+, Yb3+ and Pr3+ triply doped LiNbOsub>3sub> crystal (Er/Yb/Pr: LN) greatly enhances Er3+: 2.7 μm emission under excitation of a common 970 nm laser diode, depopulates the lower laser level of Er3+:4Isub>13/2sub>, and has little influence on the higher laser level of Er3+:4Isub>11/2sub> at the same time for population inversion. The 2.7 μm emission characteristics and energy transfer were investigated in detail. The energy transition efficiency from lower laser level of Er3+:4Isub>13/2sub> to Pr3+:3Fsub>4sub> level is as high as 0.42, indicating that the Pr3+ ion is an effective deactivation ion for Er3+ ion in LiNbOsub>3sub> crystal. These results suggest that Er/Yb/Pr: LiNbOsub>3sub> crystal may become an attractive host for developing solid state lasers at around 2.7 μm under a conventional 970 nm LD pump.

  10. Emission Properties of Yb3+/Er3+ Doped TeO2-WO3-ZnO Glasses for Broadband Optical Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Jiacheng LI; Shunguang LI; Hefang HU; Fuxi GAN

    2004-01-01

    The YbS+/Er3+ doped TeO2-WO3-ZnO glasses were prepared. The absorption spectra, emission spectra and fluorescence lifetime of Era+ at 1.5μm, excited by 970 nm were measured. The influence of Er2Oa, Yb2Oa and Ohcontents on emission properties of Era+ at 1.5 μm was investigated. The optimum doping concentrations for Era+and Yba+ is around 3.34× 1020 ions/cma and 6.63×1020 ions/cma, respectively. The peak emission cross section is 0.83~0.87 pm2. With the increasing concentration of Yba+, the FWHM of Era+ emission at 1.5 μm in the glass increases from 77 nm to 83 nm. The results show that Yba+/Era+ doped meO2-Woa-ZnO glasses are promising candidate for Era+-doped broadband optical amplifier.

  11. Highly Efficient LiYF4:Yb(3+), Er(3+) Upconversion Single Crystal under Solar Cell Spectrum Excitation and Photovoltaic Application.

    Science.gov (United States)

    Chen, Xu; Xu, Wen; Song, Hongwei; Chen, Cong; Xia, Haiping; Zhu, Yongsheng; Zhou, Donglei; Cui, Shaobo; Dai, Qilin; Zhang, Jiazhong

    2016-04-13

    Luminescent upconversion is a promising way to harvest near-infrared (NIR) sunlight and transforms it into visible light that can be directly absorbed by active materials of solar cells and improve their power conversion efficiency (PCE). However, it is still a great challenge to effectively improve the PCE of solar cells with the assistance of upconversion. In this work, we demonstrate the application of the transparent LiYF4:Yb(3+), Er(3+) single crystal as an independent luminescent upconverter to improve the PCE of perovskite solar cells. The LiYF4:Yb(3+), Er(3+) single crystal is prepared by an improved Bridgman method, and its internal quantum efficiency approached to 5.72% under 6.2 W cm(-2) 980 nm excitation. The power-dependent upconversion luminescence indicated that under the excitation of simulated sunlight the (4)F(9/2)-(4)I(15/2) red emission originally results from the cooperation of a 1540 nm photon and a 980 nm photon. Furthermore, when the single crystal is placed in front of the perovskite solar cells, the PCE is enhanced by 7.9% under the irradiation of simulated sunlight by 7-8 solar constants. This work implies the upconverter not only can serve as proof of principle for improving PCE of solar cells but also is helpful to practical application.

  12. Synthesis, structures,thermal and magnetic properties of a series of lanthanide [Ln=Sm, Gd, Er, Yb] complexes with 4-quinolineacarboxylate

    Institute of Scientific and Technical Information of China (English)

    GAO Qian; XIE Yabo; ZHANG Chong; SUN Jihong

    2009-01-01

    A series of lanthanide binuclear complexes, [Ln2(L)6(H2O)4]·2H2O (Ln=Sm(III), Gd(III), Er(III), Yb(III), HL=4-quinolineacarboxylic acid, were synthesized by reactions of corresponding rare earth salts with 4-quinolineacarboxylic acid at room temperature and were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. X-ray diffraction analyses showed that they exhibited the same binuclear architecture and crystallized in monoclinic system and P21/c space group. In four complexes, each metal center adopted nine-coordinated mode coordinated by nine O atoms from two H2O molecules and three carboxyls of three ligands, and HL showed three different coordination modes. The variable-temperature magnetic susceptibility showed that complex [Gd2(L)6(H2O)4]·2H2O performed very weak antiferromagnetic property at low temperature and exchange was almost paramagnetic at high temperature. Complexes [Er2(L)6(H2O)4]·2H2O and [Yb2(L)6(H2O)4]·2H2O performed dominating antiferromagnetic coupling.

  13. Synthesis and photophysical properties of Ir~Ⅲ-Ln~Ⅲ(Ln=Nd,Yb,Er) bimetallic complexes containing bipyrimidines as bridging ligands

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Bipyrimidines have been chosen as(NN)(NN) bridging ligands for connecting metal centers.IrⅢ-LnⅢ(Ln = Nd,Yb,Er) bimetallic complexes [Ir(dfppy)2(μ-bpm)Ln(TTA)3]Cl were synthesized by using Ir(dfppy)2(bpm)Cl as the ligand coordinating to lanthanide complexes Ln(TTA)3·2H2O.The stability constants between Ir(dfppy)2(bpm)Cl and lanthanide ions were measured by fluorescence titration.The obvious quenching of visible emission from IrⅢ complex in the IrⅢ-LnⅢ(Ln = Nd,Yb,Er) bimetallic complexes indicates that energy transfer occurred from IrⅢ center to lanthanides.NIR emissions from NdⅢ,YbⅢ,and ErⅢ were obtained under the excitation of visible light by selective excitation of the IrⅢ-based chromophore.It was proven that Ir(dfppy)2(bpm)Cl as the ligand could effectively sensitize NIR emission from NdⅢ,YbⅢ,and ErⅢ.

  14. CeNi3-type rare earth compounds: crystal structure of R3Co7Al2 (R=Y, Gd-Tm) and magnetic properties of {Gd-Er}3Co7Al2, {Tb, Dy}3Ni8Si and Dy3Co7.68Si1.32

    Science.gov (United States)

    Morozkin, A. V.; Yapaskurt, V. O.; Nirmala, R.; Quezado, S.; Malik, S. K.

    2017-03-01

    The crystal structure of new CeNi3-type {Y, Gd-Tm}3Co7Al2 (P63/mmc. N 194, hP24) compounds has been established using powder X-ray diffraction studies. The magnetism of Tb3Ni8Si and Dy3Ni8Si is dominated by rare earth sublattice and the magnetic properties of R3Co7Al2 (R =Gd-Er) and Dy3Co7.68Si1.32 are determined by both rare earth and cobalt sublattices. Magnetization data indicate ferromagnetic ordering of {Tb, Dy}3Ni8Si at 32 K and 21 K, respectively. Gd3Co7Al2 and Tb3Co7Al2 exhibit ferromagnetic ordering at 309 K and 209 K, respectively, whereas Dy3Co7Al2, Ho3Co7Al2, Er3Co7Al2 and Dy3Co7.68Si1.32 show a field dependent ferromagnetic-like ordering at 166 K, 124 K, 84 K and 226 K, respectively followed by a low temperature transition at 34 K for Dy3Co7Al2, 18 K for Ho3Co7Al2, 56 K for Er3Co7Al2, 155 K and 42 K for Dy3Co7.68Si1.32. Among these compounds, Dy3Ni8Si shows largest magnetocaloric effect (isothermal magnetic entropy change) of -11.6 J/kg·K at 18 K in field change of 50 kOe, whereas Tb3Co7Al2, Dy3Co7Al2 and Dy3Co7.68Si1.32 exhibit best permanent magnet properties in the temperature range of 2-5 K with remanent magnetization of 11.95 μB/fu, 12.86 μB/fu and 14.4 μB/fu, respectively and coercive field of 3.0 kOe, 1.9 kOe and 4.4 kOe, respectively.

  15. 氟氧化物氟化物五磷酸盐玻璃中Er3+的直接上转换增敏发光的比较%Direct Upconversion Sensitization Luminescence Comparison of the ErYb Co-doped Oxyfluoride Fluoride Pentaphosphate Glass

    Institute of Scientific and Technical Information of China (English)

    陈晓波; N.Sawanobori; 等

    2003-01-01

    本文研究了ErYb共掺的氟氧化物玻璃(ErYb:FOG)、氟化物ZBLAN玻璃和五磷酸盐非晶在966 nm半导体激光激发下的直接上转换敏化发光现象.发现有丰富的上转换发光现象,这是由于样品中Yb3+的浓度很高,Er3+-Yb3+,Yb3+-Yb3+离子之间的相互作用和能量传递作用都很强造成的.研究发现ErYb:FOG玻璃的直接上转换增敏发光比磷酸盐大100~100 000倍;而很有趣的结果在于氟氧化物玻璃的直接上转换增敏发光与ZBLAN玻璃接近;这对于提高频率上转换的综合性能是很有意义的.

  16. Ultrasmall, water dispersible, TWEEN80 modified Yb:Er:NaGd(WO4)2 nanoparticles with record upconversion ratiometric thermal sensitivity and their internalization by mesenchymal stem cells

    Science.gov (United States)

    Cascales, Concepción; Paíno, Carlos L.; Bazán, Eulalia; Zaldo, Carlos

    2017-05-01

    This work presents the synthesis by coprecipitation of diamond shaped Yb:Er:NaGd(WO4)2 crystalline nanoparticles (NPs) with diagonal dimensions in the 5-7 nm × 10-12 nm range which have been modified with TWEEN80 for their dispersion in water, and their interaction with mesenchymal stem cells (MSCs) proposed as cellular NP vehicles. These NPs belong to a large family of tetragonal Yb:Er:NaT(XO4)2 (T = Y, La, Gd, Lu; X = Mo, W) compounds with green (2H11/2 + 4S3/2 → 4I15/2) Er-related upconversion (UC) efficiency comparable to that of Yb:Er:β-NaYF4 reference compound, but with a ratiometric thermal sensitivity (S) 2.5-3.5 times larger than that of the fluoride. At the temperature range of interest for biomedical applications (˜293-317 K/20-44 °C) S = 108-118 × 10-4 K-1 for 20 at%Yb:5 at%Er:NaGd(WO4)2 NPs, being the largest values so far reported using the 2H11/2/4S3/2 Er intensity ratiometric method. Cultured MSCs, incubated with these water NP emulsions, internalize and accumulate the NPs enclosed in endosomes/lysosomes. Incubations with up to 10 μg of NPs per ml of culture medium maintain cellular metabolism at 72 h. A thermal assisted excitation path is discussed as responsible for the UC behavior of Yb:Er:NaT(XO4)2 compounds.

  17. Ultrasmall, water dispersible, TWEEN80 modified Yb:Er:NaGd(WOsub>4sub>)sub>2sub> nanoparticles with record upconversion ratiometric thermal sensitivity and their internalization by mesenchymal stem cells.

    Science.gov (United States)

    Cascales, Concepcion; Paino, Carlos; Bazán, Eulalia; Zaldo, Carlos

    2017-03-21

    This work presents the synthesis by coprecipitation of diamond shaped Yb:Er:NaGd(WOsub>4sub>)sub>2sub> crystalline nanoparticles (NPs) with diagonal dimensions in the 5-7 nm × 10-12 nm range which have been modified with TWEEN80 for their dispersion in water, and their interaction with mesenchymal stem cells (MSCs) proposed as cellular NP vehicles. These NPs belong to a large family of tetragonal Yb:Er:NaT(XOsub>4sub>)sub>2sub> (T=Y, La, Gd, Lu; X= Mo, W) compounds with green (2Hsub>11/2sub>+4Ssub>3/2sub>→4Isub>15/2sub>) Er-related upconversion (UC) efficiency comparable to that of Yb:Er:β-NaYFsub>4sub> reference compound, but with a ratiometric thermal sensitivity (S) 2.5-3.5 times larger than that of the fluoride. At the temperature range of interest for biomedical applications (~293-317 K / 20-44 ºC) S= 108-118 × 10-4 K-1 for 20at%Yb:5at%Er:NaGd(WOsub>4sub>)sub>2sub> NPs, being the largest values so far reported using the 2Hsub>11/2sub>/4Ssub>3/2sub> Er intensity ratiometric method. Cultured MSCs, incubated with these water NP emulsions, internalize and accumulate the NPs enclosed in endosomes/lysosomes. Incubations with up to 10 μg of NPs per ml of culture medium maintain cellular metabolism at 72 h. A thermal assisted excitation path is discussed as responsible for the UC behavior of Yb:Er:NaT(XOsub>4sub>)sub>2sub> compounds.

  18. Upconversion luminescence in BaYF{sub 5}, BaGdF{sub 5} and BaLuF{sub 5} nanocrystals doped with Yb{sup 3+}/Ho{sup 3+}, Yb{sup 3+}/Er{sup 3+} or Yb{sup 3+}/Tm{sup 3+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Grzyb, Tomasz, E-mail: tgrzyb@amu.edu.pl [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań (Poland); Balabhadra, Sangeetha [Department of Physics, University of Aveiro, Campus Universitario de Santiago, 3810-193, Aveiro (Portugal); Przybylska, Dominika; Węcławiak, Mariusz [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań (Poland)

    2015-11-15

    Nanomaterials based on BaREF{sub 5} fluorides (where RE = Y, Gd and Lu), doped with lanthanide ions Yb{sup 3+}/Ln{sup 3+} (Ln{sup 3+} = Er, Ho or Tm) were synthesized by microwave assisted hydrothermal method. The method of synthesis, structural and morphological properties are reported and discussed. The products obtained showed visible upconversion luminescence excited by the laser light of wavelength of 975 nm as a consequence of energy transfer between Yb{sup 3+} and remaining Ln{sup 3+} dopant ions. Their spectroscopic properties were characterized on the basis of excitation and emission spectra. Also luminescence decays and emission power dependences are presented and analysed. The materials compared revealed differences in their structural properties, reflected in their spectroscopic characteristics. The most intense luminescence was recorded for BaLuF{sub 5} based materials which exhibited upconversion also as water colloids. - Highlights: • BaREF{sub 5} nanomaterials (RE = Y, Gd or Lu) were synthesized by hydrothermal method. • Upconversion in BaREF{sub 5}:Yb{sup 3+}, Ln{sup 3+} (Ln = Ho, Er, Tm) nanocrystals was compared. • Mechanism of upconversion was analysed.

  19. Features of magnetic and thermal properties of R(Co1-xFex)2 (x≤0.16) quasibinary compounds with R=Dy, Ho, Er

    Science.gov (United States)

    Anikin, Maksim; Tarasov, Evgeniy; Kudrevatykh, Nikolay; Inishev, Aleksander; Semkin, Mikhail; Volegov, Aleksey; Zinin, Aleksander

    2016-11-01

    In this work the results of measurements of high field susceptibility, paraprocess susceptibility and thermal properties of R(Co1-xFex)2 intermetallic compounds (R=Dy, Ho, Er and x=(0-0.16)) are presented (heat capacity and magnetocaloric effect (MCE)). A magnetic structure of the Ho(Co0.88Fe0.12)2 at 293 K and 78 K was studied by neutron powder diffraction. Some peculiarities of a high-field susceptibility were revealed at low temperatures and around the Curie point (TC). In temperature range lower than TC by (100-150) K, magnetic contributions to a zero-field heat capacity were found. Studying MCE in wide temperatures range, the large change of the entropy magnetic contribution (°S) was observed which correlates with °T phenomenon. In particular, for the Er(Co0.84Fe0.16)2 compound the °S value at low temperatures is six times higher than that at Curie point. The possible reasons of such behavior were discussed.

  20. Dielectric relaxation of Y{sub 1−x}R{sub x}FeO{sub 3} (R = Dy, Er, x = 0, 0.5)

    Energy Technology Data Exchange (ETDEWEB)

    Das, Indrani, E-mail: indraani.phy@gmail.com [Department of Physics, University of Calcutta, 92, APC Road, Kolkata 700 009 (India); Chanda, Sadhan; Dutta, Alo [Department of Physics, Bose Institute, 93/1, APC Road, Kolkata 700 009 (India); Banerjee, Sourish [Department of Physics, University of Calcutta, 92, APC Road, Kolkata 700 009 (India); Sinha, T.P. [Department of Physics, Bose Institute, 93/1, APC Road, Kolkata 700 009 (India)

    2013-09-15

    Graphical abstract: Rietveld refinement plot for Y{sub 1/2}Er{sub 1/2}FeO{sub 3}. The scanning electron micrograph (SEM) of the sample is shown in the inset. Highlights: •Dielectric properties of Y{sub 1−x}R{sub x}FeO{sub 3} (R = Dy, Er, x = 0, 0.5). •Rietveld refinement of XRD profiles confirm the orthorhombic phase of the materials. •The relaxation mechanism of the samples is modeled by Cole–Cole equation. •Activation energy is found to be ∼0.27 eV •The conduction mechanism in the samples may be due to the polaron hopping based on the electron carriers. -- Abstract: The ceramic samples Y{sub 1−x}R{sub x}FeO{sub 3} (R = Dy, Er, x = 0, 0.5) are synthesized by the solid-state reaction technique. The crystal symmetries of the synthesized materials have been obtained from the Rietveld refinement of the X-ray diffraction patterns at room temperature (303 K). The homogeneity of the constituent elements and the grain sizes of the samples are determined by scanning electron microscope study. Impedance spectroscopy study of the samples has been performed in the frequency range from 50 Hz to 1 MHz and in the temperature range from 303 K to 503 K. Dielectric relaxation peaks are observed in the imaginary parts of the spectra. The frequency dependence of real and imaginary parts of dielectric permittivity is analyzed using modified Cole–Cole equation. The temperature dependence relaxation time is found to obey the Arrhenius law having activation energy ∼0.27 eV which indicates that the conduction mechanism in the samples may be due to the polaron hopping based on the electron carriers. The complex impedance plane plots of the samples indicate the presence of both grain and grain-boundary effects and are analyzed by an electrical equivalent circuit consisting a resistance and constant phase element. The frequency dependent conductivity spectra are found to follow the power law.

  1. Preparation, Characterization and Upconversion Fluorescence of NaYF4∶Yb, Er/Graphene Oxide Nanocomposites%NaYF4∶Yb,Er/氧化石墨烯纳米复合材料的制备、表征及上转换发光性能

    Institute of Scientific and Technical Information of China (English)

    嵇天浩; 郄楠; 王继梅; 滑永永; 冀志江

    2013-01-01

    采用“一锅”和直接混合两种制备过程,制得了NaYF4∶Yb,Er/氧化石墨烯(rGO)和SiO2包覆NaYF4∶Yb,Er/rGO两系列纳米复合材料.各种测试结果表明,NaYF4∶Yb,Er是以α型立方结构和纳米粒子形状存在于复合材料中,粒径主要在30~70 nm间,而rGO则较好地分散在其中,但“一锅”法制得的rGO呈现更好的分散性.Raman光谱证实,在这两种纳米材料之间存在表面耦合相互作用,且随着rGO相对含量增大,它们之间接触面积逐渐增多,相互作用也逐渐增强.上转换发光测试结果表明,rGO具有很好的发光猝灭效应和光限幅现象,尤其是对NaYF4∶Yb,Er的红光带影响更加显著.随着rGO相对含量逐渐增加,红光带发光强度逐渐降低,而绿光带变化不大.对于使用不同方法制备的样品,在具有相似含量情况下,由于团聚rGO具有更强的吸光作用,SiO2包覆样品的红光带发光强度受到rGO影响更大.

  2. Thermal decomposition of Ln(C2H5CO2)3·H2O (Ln = Ho, Er, Tm and Yb)

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude

    2012-01-01

    The thermal decomposition of Ho(III), Er(III), Tm(III) and Yb(III) propionate monohydrates in argon was studied by means of thermogravimetry (TG), differential thermal analysis (DTA), IR-spectroscopy and X-ray diffraction (XRD). Dehydration takes place around 90 °C. It is followed by the decompos...

  3. Measurement of 2 sup + sub 1 level lifetimes in sup 1 sup 6 sup 2 Yb and sup 1 sup 6 sup 2 Er by fast electronic scintillation timing

    CERN Document Server

    Caprio, M A; Casten, R F; Amro, H; Beausang, C W; Hecht, A A; Meyer, D A; Novak, J R; Ressler, J J; Zamfir, N V; Berant, Z; Barton, C J; Brenner, D S; Cooper, J R; Gill, R L; Guerdal, G; Hutter, C; Krücken, R; Pietralla, N; Regan, P H

    2003-01-01

    Lifetime measurements for the 2 sup + sub 1 levels of sup 1 sup 6 sup 2 Er and sup 1 sup 6 sup 2 Yb were obtained in beta sup + /epsilon decay at the Yale Moving Tape Collector by fast electronic scintillation timing of beta sup +gamma coincidences. (orig.)

  4. Acousto-optic Q-switched laser performances of Er3+∶yb3+∶LuAl3(BO3)4 crystal at 1.5-1.6 μm

    Institute of Scientific and Technical Information of China (English)

    Yujin Chen; Yanfu Lin; Haiyong Zhu; Ge Zhang; Yidong Huang

    2012-01-01

    Diode-pumped acousto-optic Q-switched pulse laser at 1.5-1.6μm is obtained in an Er3+:Yb3+:LuAl3 (BO3)4 crystal. Single-pulse laser operation with slope efficiency of 14% and threshold of approximately 100 mW is realized at an average absorbed pump power of 314 mW and repetition frequency of 20 kHz. Output pulse energy is 67 μJ. The effects of pulse repetition frequency, absorbed pump power, and duty cycle on the wavelength and pulse profile of the Q-switched Er3+:Yb3+:LuAl3(BO3)4 laser are also investigated.%Diode-pumped acousto-optic Q-switched pulse laser at 1.5-1.6 μm is obtained in an Er3+∶Yb3+∶LuAl3 (BO3)4 crystal.Single-pulse laser operation with slope efficiency of 14% and threshold of approximately 100 mW is realized at an average absorbed pump power of 314 mW and repetition frequency of 20 kHz.Output pulse energy is 67 μJ.The effects of pulse repetition frequency,absorbed pump power,and duty cycle on the wavelength and pulse profile of the Q-switched Er3+∶yb3+∶LuAl3(BO3)4 laser are also investigated.

  5. Upconversion luminescence properties of Y2O2S:Er3+@Y2O2S:Yb3+,Tm3+ core-shell nanoparticles prepared via homogeneous co-precipitation

    Science.gov (United States)

    Tian, Ying; Lu, Fei; Xing, Mingming; Ran, Jincheng; Fu, Yao; Peng, Yong; Luo, Xixian

    2017-02-01

    The Y2O2S:Er3+@Y2O2S:Yb3+,Tm3+ core-shell upconversion (UC) nanoparticles with average diameter of 95 nm were synthesized by the homogeneous co-precipitation method combining with the solid-gas sulfidation route. The increases of nanocrystaline size after the shell coating was observed both in the X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. This indicates the composition homogeneity core-shell Y2O2S nanocrystals. Meanwhile, the luminescence of both the Er3+ and Tm3+ ions are realized for the first time in the novel core-shell Y2O2S:Er3+@Y2O2S:Yb3+,Tm3+ nanoparticles under the excitations of both 980 and 1550 nm. When excited by a 980 nm laser diode, the Y2O2S:Er3+@Y2O2S:Yb3+,Tm3+ phosphor exhibits blue (≈475 nm), green (≈548 nm) and red (≈670 nm) emissions in the visible region, which correspond to the 1G4 → 3H6 transition of Tm3+ions, 4S3/2, 2H11/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. The very strong emission at the near infrared (NIR) region is mainly due to the 3H4 → 3H6 transition of Tm3+ ions. The emission from both of Er3+ and Tm3+ ions under 980 nm excitation reveals the energy transfers of Yb3+ → Tm3+ within the shell layer and Yb3+ → Er3+ between the shell and the core. When pumping at 1550 nm, although only Er3+ ions can efficiently absorb the excitation energy, the strong UC emissions from Tm3+ ions were also observed. This is owing to the energy transfer between the core and the shell through Er3+ → Yb3+ → Tm3+ ions.

  6. A portable luminescent thermometer based on green up-conversion emission of Er3+/Yb3+ co-doped tellurite glass

    Science.gov (United States)

    Manzani, Danilo; Petruci, João Flávio Da Silveira; Nigoghossian, Karina; Cardoso, Arnaldo Alves; Ribeiro, Sidney J. L.

    2017-01-01

    The determination of temperature is essential in many applications in the biomedical, technological, and industrial fields. Optical thermometry appears to be an excellent alternative for conventional electric temperature sensors because it is a non-contact method that offers a fast response, electromagnetic passivity, and high temperature sensitivity. In this paper, we propose an optical thermometer probe comprising an Er3+/Yb3+ co-doped tellurite glass attached to the tip of an optical fibre and optically coupled to a laser source and a portable USB spectrometer. The ratio of the up-conversion green emission integrated peak areas when excited at 980 nm was temperature dependent, and it was used to calibrate the thermometer. The thermometer was operated in the range of 5–50 °C and 50–200 °C, and it revealed excellent linearity (r2 > 0.99), suitable accuracy, and precisions of ±0.5 and ±1.1 °C, respectively. By optimizing Er3+ concentration, we could obtain the high green emission intensity, and in turn, high thermal sensitivity for the probe. The probe fabricated in the study exhibited suitable properties for its application as a temperature sensor and superior performance compared to other Er3+ -based optical thermometers in terms of thermal sensitivity.

  7. Ce(3+)/Yb(3+)/Er(3+) triply doped bismuth borosilicate glass: a potential fiber material for broadband near-infrared fiber amplifiers.

    Science.gov (United States)

    Chu, Yushi; Ren, Jing; Zhang, Jianzhong; Peng, Gangding; Yang, Jun; Wang, Pengfei; Yuan, Libo

    2016-09-20

    Erbium doped bismuth borosilicate (BBS) glasses, possessing the broadest 1.55 μm near infrared (NIR) emission band among oxide glasses, stand out as excellent fiber material for optical fiber amplifiers. In this work, we demonstrate that both broadened and enhanced NIR emission of Er(3+) can be obtained by sensibly combining the effects such as mixed glass former effect, phonon-assisted energy transfer (PAET) and de-excitation effect induced by codopant. Specially, by codoping CeO2 in a controlled manner, it leads to not only much improved optical quality of the glasses, enhanced NIR emission, but also significantly suppressed energy transfer up-conversion (ETU) luminescence which is detrimental to the NIR emission. Cerium incorporated in the glasses exists overwhelmingly as the trivalent oxidation state Ce(3+) and its effects on the luminescence properties of Er(3+) are discussed. Judd-Ofelt analysis is used to evaluate gain amplification of the glasses. The result indicates that Ce(3+)/Yb(3+)/Er(3+) triply doped BBS glasses are promising candidate for erbium doped fiber amplifiers. The strategy described here can be readily extended to other rare-earth ions (REs) to improve the performance of REs doped fiber lasers and amplifiers.

  8. Ce3+/Yb3+/Er3+ triply doped bismuth borosilicate glass: a potential fiber material for broadband near-infrared fiber amplifiers

    Science.gov (United States)

    Chu, Yushi; Ren, Jing; Zhang, Jianzhong; Peng, Gangding; Yang, Jun; Wang, Pengfei; Yuan, Libo

    2016-01-01

    Erbium doped bismuth borosilicate (BBS) glasses, possessing the broadest 1.55 μm near infrared (NIR) emission band among oxide glasses, stand out as excellent fiber material for optical fiber amplifiers. In this work, we demonstrate that both broadened and enhanced NIR emission of Er3+ can be obtained by sensibly combining the effects such as mixed glass former effect, phonon-assisted energy transfer (PAET) and de-excitation effect induced by codopant. Specially, by codoping CeO2 in a controlled manner, it leads to not only much improved optical quality of the glasses, enhanced NIR emission, but also significantly suppressed energy transfer up-conversion (ETU) luminescence which is detrimental to the NIR emission. Cerium incorporated in the glasses exists overwhelmingly as the trivalent oxidation state Ce3+ and its effects on the luminescence properties of Er3+ are discussed. Judd-Ofelt analysis is used to evaluate gain amplification of the glasses. The result indicates that Ce3+/Yb3+/Er3+ triply doped BBS glasses are promising candidate for erbium doped fiber amplifiers. The strategy described here can be readily extended to other rare-earth ions (REs) to improve the performance of REs doped fiber lasers and amplifiers. PMID:27646191

  9. Annealing behaviour of structure and morphology and its effects on the optical gain of Er3+/Yb3+ co-doped Al2O3 planar waveguide amplifier

    Institute of Scientific and Technical Information of China (English)

    Tan Na; Zhang Qing-Yu

    2006-01-01

    Using transmission electron microscopy (TEM) and x-ray diffraction analysis, we have studied the structural and morphological evolution of highly Er/Yb co-doped Al2O3 films in the temperature range from 600℃-900℃. Bycomparison with TEM observation, the annealing behaviours of photoluminescence (PL) emission and optical loss were found to have relation to the structure and morphology. The increase of PL intensity and optical loss above 800℃ might result from the crystallization of amorphous Al2O3 films. Based on the study on the structure and morphology,a rate equation propagation model of a multilevel system was used to calculate the optical gains of Er-doped Al2O3 planar waveguide amplifiers involving the variation of PL efficiency and optical loss with annealing temperature. It was found that the amplifiers had an optimized optical gain at the temperature corresponding to the minimum of optical loss, rather than at the temperature corresponding to the maximum of PL efficiency, suggesting that the optical loss is a key factor for determining the optical gain of an Er-doped Al2O3 planar waveguide amplifier.

  10. One-step synthesis of Yb3 + , Er3 + -codoped YF3 nanoparticles via nano-reactor and their spectral characteristic%利用“纳米反应器”一步合成YF3:Yb3+,Er3+纳米粒子及光谱特性

    Institute of Scientific and Technical Information of China (English)

    曹亮军; 田雪英; 刘伟; 闫景辉; 翟庆洲; 连洪洲

    2011-01-01

    采用微乳液法在室温下快速合成出YF3:Yb3+,Er3+纳米粒子,X射线衍射图(XRD)与YF3标准卡片PDF#74-911非常吻合,经扫描电镜( SEM)分析表明所制备的纳米粒子为球形,粒径约为32 nm.同时研究了YF3:Yb3,Er3+的下转换光谱和上转换光谱,实验发现,下转换光谱最强发射峰位于1544 nm;在上转换光谱中,这两种离子主要发红光和绿光,且红光强于绿光,通过分析输出光强与泵浦光强的双对数曲线,发现不管是红光还是绿光都是双光子发射,最后对红、绿光的上转换机理进行了分析.%Yb3+ , Er3 + -codoped YF3 nanoparticles were rapidly prepared via microemulsion method at room temperature. The nanoparticles were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD pattern matched well with card PDF#74-911. SEM patterns indicated that the nanoparticles were spherical morphology with the average size about 32 nm. Downconversion spectrum and upconversion spectrum were investigated. It was found that the predominant emission peak of downconversion spectrum was located at 1544 nm. In the upconversion spectrum, the intensity of red emission was stronger than that of green. In this material, both the red and green emissions were due to two photon processes. Meanwhile, upconversion mechanism and process were also analyzed.

  11. Improving pure red upconversion emission of Co-doped Y{sub 2}O{sub 3}:Yb{sup 3+}–Er{sup 3+} nanocrystals with a combination of sodium sulfide and surfactant Pluronic-F127

    Energy Technology Data Exchange (ETDEWEB)

    López-Luke, T., E-mail: tzarara@cio.mx [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37160, México (Mexico); De la Rosa, E., E-mail: elder@cio.mx [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37160, México (Mexico); Campos Villalobos, I. [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37160, México (Mexico); Rodriguez, R.A. [Universidad de Guadalajara, Unidad Lagos, Lagos de Moreno, Jal. 47460, México (Mexico); Ángles-Chávez, C. [Instituto Mexicano del Petróleo, Cd. México, D.F. 07730, México (Mexico); Salas, P. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, A.P. 1-1010, Querétaro, Qro. 76000, México (Mexico); Wheeler, Damon A.; Zhang, J.Z. [Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA 95064 (United States)

    2014-01-15

    Nanocrystals of Y{sub 2}O{sub 3}:Yb{sup 3+}–Er{sup 3+} (2:1 mol% Yb{sup 3+}:Er{sup 3+}) were prepared by a novel precipitation technique using Na{sub 2}S and Pluronic-F127 (PF127) surfactant. Crystal structure, particle size, red emission intensity and fluorescence decay lifetimes were determined using microscopy and spectroscopy techniques. TEM analysis indicates that the average particle size ranged from 40 to 70 nm. The nanocrystals showed a strong red emission band centered at 663 nm after excitation at 970 nm. The upconverted signal intensity was improved 250% with an optimum concentration of Na{sub 2}S (0.48 M) and PF127 (0.1 mM). The improvement was explained in terms of the reduction of surface contaminants as well as the cubic crystalline phase of the parent Y{sub 2}O{sub 3} material. Interestingly, the formation of sulfates (SO{sub 4}{sup 2−}) is faster than that of O–H, which is responsible for quenching the red and green emissions. The results suggest that Na{sub 2}S and PF127 are good candidates for surface passivation, especially when used in conjunction. The preparation of Y{sub 2}O{sub 3}:Yb{sup 3+}–Er{sup 3+} using Na{sub 2}S with strong red emission band was produced at a lower cost than that of other sulfuration processes. -- Highlights: • . • Strong red emission band centered at 663 nm was obtained after excitation at 970 nm. • Yb-Er codoped Y2O3 nanocrystals with average size ranging from 40 to 70 nm. • Improvement of the red emission in Y2O3:Yb-Er nanocrystals by the introduction of sodium sulfide and pluronic. • Passivation of nanocrystal surface with sodium sulfide and pluoronic.

  12. A facile single-step procedure for the synthesis of luminescent Ln{sup 3+}:YVO{sub 4} (Ln = Eu or Er + Yb)-silica nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Ocana, Manuel, E-mail: mjurado@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla, CSIC-US, Americo Vespucio 49, 41092 Isla de la Cartuja, Sevilla (Spain); Cantelar, Eugenio; Cusso, Fernando [Depto. Fisica de Materiales, C-IV, Universidad Autonoma de Madrid (Spain)

    2011-01-01

    A simple and single-step method for the production of Ln-doped YVO{sub 4} nanocrystals and their simultaneous encapsulation in a silica network based on the pyrolysis of liquid aerosols at 800 deg. C is reported. The procedure is illustrated for Yb,Er:YVO{sub 4}-silica nanocomposites consisting of spherical particles, which present up-converted green luminescence after IR excitation whose efficiency increased on annealing up to 1000 deg. C due to the release of impurities (adsorbed water, and residual anions). XPS spectroscopy and TEM observations revealed that the surface of the composite particles was enriched in silica, which would facilitate their functionalisation required to use them in biological applications. The procedure can also be used to prepare other rare earth doped systems as illustrated for the case of Eu-doped YVO{sub 4}/silica having down-converted red luminescence.

  13. Fabrication of freestanding silk fibroin films containing Ag nanowires/NaYF4:Yb,Er nanocomposites with metal-enhanced fluorescence behavior.

    Science.gov (United States)

    Zhao, Bing; Qi, Ning; Zhang, Ke-Qin; Gong, Xiao

    2016-06-01

    Solar cells containing upconversion nanoparticles (UCNPs) used as a power source in biomedical nanosystems have attracted great interest. However, such solar cells further need to be developed because their substrate materials should be biocompatible, flexible and highly luminescent. Here, we report that freestanding silk fibroin (SF) films containing a mesh of silver nanowires (AgNWs) and β-NaYF4:Yb,Er nanocrystals with metal-enhanced fluorescence behavior can be fabricated. The freestanding composite films exhibit properties such as good optical transparency, conductivity and flexibility. Furthermore, they show significantly enhanced upconversion fluorescence due to surface plasmon polaritons (SPPs) of AgNWs compared to the SF-UCNP films without AgNWs. The freestanding composite films with metal-enhanced fluorescence behavior show great promise for future applications in self-powered nanodevices such as cardiac pacemakers, biosensors and nanorobots.

  14. Rich stochastic dynamics of co-doped Er:Yb fluorescence upconversion nanoparticles in the presence of thermal, non-conservative, harmonic and optical forces

    Science.gov (United States)

    Nome, Rene A.; Sorbello, Cecilia; Jobbágy, Matías; Barja, Beatriz C.; Sanches, Vitor; Cruz, Joyce S.; Aguiar, Vinicius F.

    2017-03-01

    The stochastic dynamics of individual co-doped Er:Yb upconversion nanoparticles (UCNP) were investigated from experiments and simulations. The UCNP were characterized by high-resolution scanning electron microscopy, dynamic light scattering, and zeta potential measurements. Single UCNP measurements were performed by fluorescence upconversion micro-spectroscopy and optical trapping. The mean-square displacement (MSD) from single UCNP exhibited a time-dependent diffusion coefficient which was compared with Brownian dynamics simulations of a viscoelastic model of harmonically bound spheres. Experimental time-dependent two-dimensional trajectories of individual UCNP revealed correlated two-dimensional nanoparticle motion. The measurements were compared with stochastic trajectories calculated in the presence of a non-conservative rotational force field. Overall, the complex interplay of UCNP adhesion, thermal fluctuations and optical forces led to a rich stochastic behavior of these nanoparticles.

  15. Generation of high energy square-wave pulses in all anomalous dispersion Er:Yb passive mode locked fiber ring laser.

    Science.gov (United States)

    Semaan, Georges; Ben Braham, Fatma; Salhi, Mohamed; Meng, Yichang; Bahloul, Faouzi; Sanchez, François

    2016-04-18

    We have experimentally demonstrated square pulses emission from a co-doped Er:Yb double-clad fiber laser operating in anomalous dispersion DSR regime using the nonlinear polarization evolution technique. Stable mode-locked pulses have a repetition rate of 373 kHz with 2.27 µJ energy per pulse under a pumping power of 30 W in cavity. With the increase of pump power, both the duration and the energy of the output square pulses broaden. The experimental results demonstrate that the passively mode-locked fiber laser operating in the anomalous regime can also realize a high-energy pulse, which is different from the conventional low-energy soliton pulse.

  16. Enhanced upconversion emission in crystallization-controllable glass-ceramic fiber containing Yb3+-Er3+ codoped CaF2 nanocrystals

    Science.gov (United States)

    Peng, Wencai; Fang, Zaijin; Ma, Zhijun; Qiu, Jianrong

    2016-10-01

    Functional nanocrystal-containing materials have been a hot topic in recent years. However, few researches have focused on functional nanocrystals contained in optical glass fibers. In this research, transparent CaF2 glass-ceramic was prepared by a melt-quenching method. Greatly enhanced upconversion luminescence was observed after heat treatment. By applying a novel method called melt-in-tube, precursor fiber free of crystals was fabricated at the drawing temperature where the clad was softened while the core was melted. Glass-ceramic fiber with fiber core containing Yb3+-Er3+ codoped CaF2 nanocrystals was obtained after heat treatment at a relatively low temperature. Electron probe micro-analyzer measurement shows no obvious element diffusion between the core and clad. Greatly enhanced upconversion emission was detected in the glass-ceramic fiber excited by a 980 nm laser, suggesting the developed glass-ceramic fiber is a promising material for upconversion laser.

  17. Enhanced upconversion emission in crystallization-controllable glass-ceramic fiber containing Yb(3+)-Er(3+) codoped CaF2 nanocrystals.

    Science.gov (United States)

    Peng, Wencai; Fang, Zaijin; Ma, Zhijun; Qiu, Jianrong

    2016-10-07

    Functional nanocrystal-containing materials have been a hot topic in recent years. However, few researches have focused on functional nanocrystals contained in optical glass fibers. In this research, transparent CaF2 glass-ceramic was prepared by a melt-quenching method. Greatly enhanced upconversion luminescence was observed after heat treatment. By applying a novel method called melt-in-tube, precursor fiber free of crystals was fabricated at the drawing temperature where the clad was softened while the core was melted. Glass-ceramic fiber with fiber core containing Yb(3+)-Er(3+) codoped CaF2 nanocrystals was obtained after heat treatment at a relatively low temperature. Electron probe micro-analyzer measurement shows no obvious element diffusion between the core and clad. Greatly enhanced upconversion emission was detected in the glass-ceramic fiber excited by a 980 nm laser, suggesting the developed glass-ceramic fiber is a promising material for upconversion laser.

  18. Infrared study of Er(3+)/Yb(3+) Co-Doped GeO(2)-PbO-Bi(2)O(3) glass.

    Science.gov (United States)

    Bahari, Hamid-Reza; Sidek, Hj A A; Adikan, Faisal Rafiq M; Yunus, Wan M M; Halimah, Mohamed K

    2012-01-01

    Heavy metal oxide glasses, containing bismuth and/or lead in their glass structure are new alternatives for rare eart (RE) doped hosts. Hence, the study of the structure of these vitreous systems is of great interest for science and technology. In this research work, GeO(2)-PbO-Bi(2)O(3) glass host doped with Er(3+)/Yb(3+) ions was synthesized by a conventional melt quenching method. The Fourier transform infrared (FTIR) results showed that PbO and Bi(2)O(3) participate with PbO(4) tetragonal pyramids and strongly distort BiO(6) octahedral units in the glass network, which subsequently act as modifiers in glass structure. These results also confirmed the existence of both four and six coordination of germanium oxide in glass matrix.

  19. Modeling of the Co2+saturable absorber Q-switch for the Er:Yb:glass laser (1.534 um)

    Science.gov (United States)

    Gruber, John B.; Kennedy, Ann W.; Zandi, Bahram; Hutchinson, James A.

    2000-03-01

    We have modeled the passive Q-switch performance of divalent cobalt and its spectroscopic parameters in various host media for the Er:Yb:Glass laser that operates near 1.534 micrometers . Our method involves the use of rate equations that assume a three-level gain medium and a four-level absorber medium including excited-state absorption. Numerical integration techniques are used where analytical functions are unobtainable to describe the dynamics within the systems that we have examined. Input into the rate equations is obtained from experimental data that include Co2+ ion concentrations, cross-sections, and lifetimes obtained by time-resolved spectroscopy. The calculated laser output in terms of pulse energies and pulsewidths in ns is compared with experimental results based on different Co2+ absorber host matricies and different cavity designs.

  20. Wideband saturable absorption in few-layer molybdenum diselenide (MoSe2) for Q-switching Yb-, Er- and Tm-doped fiber lasers

    CERN Document Server

    Woodward, R I; Runcorn, T H; Hu, G; Torrisi, F; Kelleher, E J R; Hasan, T

    2015-01-01

    We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorber by embedding liquid-phase exfoliated few-layer MoSe2 flakes into a polymer film. The MoSe2-polymer composite is used to Q-switch fiber lasers based on ytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains of microsecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nm and 1924 nm, respectively. Such operating wavelengths correspond to sub-bandgap saturable absorption in MoSe2, which is explained in the context of edge-states, building upon studies of other semiconducting transition metal dichalcogenide (TMD)-based saturable absorbers. Our work adds few-layer MoSe2 to the growing catalog of TMDs with remarkable optical properties, which offer new opportunities for photonic devices.

  1. Pressure and temperature dependent up-conversion properties of Yb3+-Er3+ co-doped BaBi4Ti4O15 ferroelectric ceramics

    Institute of Scientific and Technical Information of China (English)

    戚兴国; 随志磊; 邓宇航; 代如成; 王中平; 张增明; 丁泽军

    2014-01-01

    Yb3+ and Er3+ co-doped BaBi4Ti4O15 (BBT) ceramic samples showed brighter up-conversion photoluminescence (UC-PL) under excitation of 980 nm. The monotonous increase of fluorescence intensity ratio (FIR) from 525 to 550 nm with temperature showed that this material could be used for temperature sensing with the maximum sensitivity to be 0.0046 K-1 and the energy dif-ference was 700 cm-1. Moreover, the sudden change of red and green emissions around 400 ºC might imply a phase transition. With increasing pressure up to 4 GPa, the PL intensity decreased but was still strong enough. These results illustrated the wide applications of BBT in high temperature and high pressure conditions.

  2. Thermal and pump power effect in SrMoO4:Er3+-Yb3+ phosphor for thermometry and optical heating

    Science.gov (United States)

    Soni, Abhishek Kumar; Rai, Vineet Kumar

    2017-01-01

    The pump power and temperature dependence study in the Er3+-Yb3+ codoped SrMoO4 phosphors for the green UC emission bands has been investigated by using two NIR (980 nm and 808 nm) laser radiation. The thermometric behaviour of the codoped phosphor operated in the 300-543 K gives maximum sensitivity ∼25.5 × 10-3 K-1 for 980 nm excitation whereas, for 808 nm excitation the maximum sensitivity is ∼21.5 × 10-3 K-1 over 300-465 K. The optical heating study upon two NIR laser radiations has also been performed. The experimental observations made in this article may be of significant interest for thermometry and optical heating.

  3. Optimization of synthesis of upconversion luminescence material NaYF4:Er3+,Yb3+ nanometer-phosphor by low-temperature combustion synthesis method

    Institute of Scientific and Technical Information of China (English)

    LU Liping; ZHANG Xiyan

    2013-01-01

    A kind of Er3+-yb3+ co-doped natrium yttrium fluoride nanometer-phosphor sensitive to 980 nm was synthesized by the low-temperature combustion synthesis method,which expanded the application range of the low-temperature combustion synthesis (LCS) method which is always used in the synthesis of oxides and compound oxides.The synthesis conditions were optimized with orthogonal experiments and the optimum technological parameters were obtaincd.Intense upconversion emissions at 522,540 and 653 nm corresponding to the 2H11/2,4S3/2,and 4F9/2 transitions to the 4I15/2 ground state were observed when excited by continuous wavclength (CW) laser radiation at 980 nm.The effect of the carbamide amount on the phase formation and the luminescence intensity was analyzed.The average particle size of the sample was 30-40 nm.

  4. Variations of magnetocaloric effect and magnetoresistance across RCuGe (R=Tb, Dy, Ho, Er) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Sachin; Suresh, K.G., E-mail: suresh@phy.iitb.ac.in

    2015-10-01

    RCuGe (R=Tb–Er) compounds have been studied by structural, magnetic, magnetocaloric and magnetotransport measurements. All these compounds are iso-structural and show antiferromagnetic ordering below their Néel temperatures (T{sub N}). Except TbCuGe, all the studied compounds show large magnetocaloric effect (MCE), arising due to the field induced metamagnetic transition. They also show a sign reversal of magnetoresistance (MR) with change in temperature or field. The non-monotonic variation of the magnitude of MR is attributed to the competing effects of Lorentz force, changes in the spin disorder scattering and the spin fluctuations. - Highlights: • RCuGe (R=Tb–Er) compounds show low temperature antiferromagnetic ordering. • All compounds show field induced metamagnetic transitions. • These compounds show large magnetocaloric effect and magnetoresistance.

  5. Influence of Cr{sup 3+} ions doping on growth and upconversion luminescence properties of β-NaYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microcrystals

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chuanying [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Cheng, Xianhua, E-mail: xhcheng@sjtu.edu.cn [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2015-11-15

    β-NaYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microcrystals codoped with Cr{sup 3+} ions were prepared for the first time via a facile hydrothermal method. The influence of doping concentration of Cr{sup 3+} ions on growth and upconversion (UC) luminescence properties of β-NaYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microcrystals were investigated in detail. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra and photoluminescence (PL) spectra were used for characterization. The results demonstrated that the morphology and size of β-NaYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microcrystals were influenced by doping concentration of Cr{sup 3+} ions, the possible mechanism was proposed. The UC intensity of β-NaYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microcrystals was significantly enhanced by doping of Cr{sup 3+} ions. In contrast to β-NaYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microcrystals without doping of Cr{sup 3+} ions, the green and red emission intensities of the microcrystals codoped with 15 mol% Cr{sup 3+} ions were enhanced by 16 and 7 times, respectively. The enhancement of the UC intensities should be ascribed to the distortion of local symmetry around Er{sup 3+} ions, the UC mechanism was discussed. This work will be helpful for improving the UC intensity of other lanthanide-doped UC nano- and micro-crystals. - Highlights: • β-NaYF{sub 4}:Yb{sup 3+}/Er{sup 3+} crystals codoped with Cr{sup 3+} ions were synthesized. • The effects of Cr{sup 3+} ions on growth of β-NaYF{sub 4} crystals were clarified. • The green and red UC intensities were enhanced by 16 and 7 times, respectively. • The UC mechanism of β-NaYF{sub 4} crystals codoped with Cr{sup 3+} ions was proposed.

  6. The interplay between magnetism and superconductivity in RNi 2B 2C (R dbnd Lu, Tm, Er, Ho, Dy, Tb, Gd)

    Science.gov (United States)

    El Massalami, M.; Bud'ko, S. L.; Giordanengo, B.; Baggio-Saitovitch, E. M.

    1995-02-01

    The superconducting and magnetic phase diagram (characteristic temperatures versus effective ionic radii) of the RNi 2B 2C (R dbnd Lu, Tm, Er, Ho, Dy, Tb, Gd) compounds are considered. Although the gradual degradation of superconductivity can be scaled to the de Gennes factor, ( g-1) 2J( J + 1), the unique reentrant behavior of the HoNi 2B 2C compound and the abrupt quenching of superconductivity for R lighter than Ho are most probably unaccountable within this scheme. Rather, it is argued that their low- T magnetic and transport properties as well as the main features of the interplay between magnetism and superconductivity can be accounted for if the low- T magnetism of HoNi 2B 2C, as reported by Grigereit et al., is generalized to the other isomorphous R members. Thus the onset of the 4f moments antiferromagnetic state at T1 is accompanied by an oscillatory component, which transforms to a commensurate antiferromagnetic state at T2. For HoNi 2B 2C, the pressure and magnetic-field influence on Tc, T1 and T2 will be discussed.

  7. Bifunction in Er{sup 3+}/Yb{sup 3+} co-doped BaTi{sub 2}O{sub 5}–Gd{sub 2}O{sub 3} glasses prepared by aerodynamic levitation method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Minghui [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Yu, Jianding; Pan, Xiuhong [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Cheng, Yuxing [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Liu, Yan, E-mail: liuyan@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2013-11-15

    Graphical abstract: - Highlights: • Novel BaTi{sub 2}O{sub 5}–Gd{sub 2}O{sub 3} based glasses have been prepared by aerodynamic levitation. • The obtained glasses show high thermal stability with T{sub g} = 763.3 °C. • Er{sup 3+}/Yb{sup 3+} co-doped glasses show strong upconversion based on a two-photon process. • Red emission is stronger than green emissions for EBT by high Yb{sup 3+} concentration. • Magnetic ions are paramagnetic and the distribution is homogeneous in the glasses. - Abstract: Novel Er{sup 3+}/Yb{sup 3+} co-doped BaTi{sub 2}O{sub 5}–Gd{sub 2}O{sub 3} spherical glasses have been fabricated by aerodynamic levitation method. The thermal stability, upconversion luminescence, and magnetic properties of the present glass have been studied. The glasses show high thermal stability with 763.3 °C of the onset temperature of the glass transition. Red and green emissions centered at 671 nm, 548 nm and 535 nm are obtained at 980 nm excitation. The upconversion is based on a two-photon process by energy transfer, excited-state absorption, and energy back transfer. Yb{sup 3+} ions are more than Er{sup 3+} ions in the glass, resulting in efficient energy back transfer from Er{sup 3+} to Yb{sup 3+}. So the red emission is stronger than the green emissions. Magnetization curves indicate that magnetic rare earth ions are paramagnetic and the distribution is homogeneous and random in the glass matrix. Aerodynamic levitation method is an efficient way to prepare glasses with homogeneous rare earth ions.

  8. Synthesis, structure, magnetism, and optical properties of theordered mixed-lanthanide sulfides gamma-LnLn'S3 (Ln=La, Ce; Ln'=Er, Tm,Yb)

    Energy Technology Data Exchange (ETDEWEB)

    Jin, G.B.; Choi, E.S.; Guertin, R.P.; Brooks, J.S.; Bray, T.H.; Booth, C.H.; Albrecht-Schmitt, T.E.

    2006-12-12

    {gamma}-LnLn{prime}S{sub 3} (Ln = La, Ce; Ln{prime} = Er, Tm, Yb) have been prepared as dark red to black single crystals by the reaction of the respective lanthanides with sulfur in a Sb{sub 2}S{sub 3} flux at 1000 C. This isotypic series of compounds adopts a layered structure that consists of the smaller lanthanides (Er, Tm, and Yb) bound by sulfide in six- and seven-coordinate environments that are connected together by the larger lanthanides (La and Ce) in eight- and nine-coordinate environments. The layers can be broken down into three distinct one-dimensional substructures containing three crystallographically unique Ln{prime} centers. The first of these is constructed from one-dimensional chains of edge-sharing [Ln{prime}S{sub 7}] monocapped trigonal prisms that are joined to equivalent chains via edge-sharing to yield ribbons. There are parallel chains of [Ln{prime}S{sub 6}] distorted octahedra that are linked to the first ribbons through corner-sharing. These latter units also share corners with a one-dimensional ribbon composed of parallel chains of [Ln{prime}S{sub 6}] polyhedra that edge-share both in the direction of chain propagation and with adjacent identical chains. Magnetic susceptibility measurements show Curie-Weiss behavior from 2 to 300 K with antiferromagnetic coupling, and no evidence for magnetic ordering. The {theta}{sub p} values range from -0.4 to -37.5 K, and spin-frustration may be indicated for the Yb-containing compounds. All compounds show magnetic moments substantially reduced from those calculated for the free ions. The optical band gaps for {gamma}-LaLn{prime}S{sub 3} (Ln{prime} = Er, Tm, Yb) are approximately 1.6 eV, whereas {gamma}-CeLn{prime}S{sub 3} (Ln{prime} = Er, Tm, Yb) are approximately 1.3 eV.

  9. Effect of Fluoride Concentration on The Phase of NaYF4∶Yb3 +, Er3 + Synthesized in Ionic Liquid%离子液体合成方法中氟离子浓度对NaYF4∶Yb3+,Er3+形貌、晶相及发光性质的影响

    Institute of Scientific and Technical Information of China (English)

    刘甲; 单含; 刘晓敏; 孔祥贵

    2012-01-01

    Water soluble NaYF4: 20% Yb3+,2% Er3 + upconversion nanoparticles were prepared in ionic liquid. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) , and luminescence spectra. The morphology and crystal structure could be well controlled by adjusting the fluoride concentration. Based on the experimental date, the high fluoride concentration was in favor of the formation of hexagonal phase. The products could be dissolved in water and the solution exhibit bright green luminescence under the excitation of 980 run laser.%以离子液体作为溶剂合成了立方相、混相和六角相的水溶性NaYF4∶20% Yb3+,2% Er3+上转换发光纳米粒子,用扫描电镜(SEM)、X射线粉末衍射(XRD)、发光光谱测量等手段对水溶性纳米粒子进行了形貌、晶相和发光性质表征.结果表明,高的氟离子浓度对六角相NaYF4的形成有促进作用,其中六角相的产物表现出良好的发光性质和水溶性.

  10. Photocatalytic sterilization of TiO2 nanocrystals co-doped by Er3+-Yb3+%Er3+-Yb3+共掺纳米TiO2上转换光催化杀菌作用研究

    Institute of Scientific and Technical Information of China (English)

    王文兰; 尚庆坤; 郑伟; 于辉; 张雅斌; 李国强

    2008-01-01

    采用溶胶凝胶法合成了稀土离子Er3+-Yb3+共掺杂的纳米TiO2晶体粉末,利用XRD,UV-VIS吸收光谱及上转换发射光谱对其结构和光学特性进行了表征.以致病性嗜水气单胞菌为实验菌株,以980 mm激光为激发光源,考察了室温下Er3+-Yb3+共掺杂纳米TiO2的光催化杀菌性能.结果表明,稀土离子掺杂的纳米TiO2可以通过上转换发光的途径增加TiO2对可见光的利用率,从而实现TiO2在可见光和近红外光范围的光催化氧化杀菌作用.

  11. Single-Frequency, Yb-Free, Resonantly Cladding-Pumped Large Mode Area Er Fiber Amplifier for Power Scaling

    Science.gov (United States)

    2008-07-25

    report results for a single-frequency SF resonantly cladding-pumped Yb-free large mode area LMA erbium-doped fiber amplifier EDFA with nearly 50...original demonstration of a SF resonantly cladding-pumped LMA EDFA . We obtained a diffraction-limited SF output of 9.3 W, which is also a record power...output obtained for resonantly cladding-pumped LMA EDFA . © 2008 American Institute of Physics. DOI: 10.1063/1.2964189 Recent advances in eye-safe 1.5

  12. [The enhancement of 1.5 microm near infrared luminescence in Er3+ and Yb3+ codoped Y2O3 nanocrystalline].

    Science.gov (United States)

    Meng, Qing-Yu; Chen, Bao-Jiu; Lü, Shu-Chen; Sun, Jiang-Ting; Qu, Xiu-Rong

    2010-05-01

    Y0.96 Er0.02 Yb0.02)O3 nanocrystals of 10 and 40 nm average particle size were prepared by combustion method. And bulk materials of the same components were obtained by annealing at 1 200 degrees C. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, transmission electron microscope (TEM), and scanning electron microscopy (SEM) were used to characterize the crystal structure and morphology of the samples. The upconversion emission spectra and NIR (near-infrared) emission spectra were measured, under 980 nm excitation. The research result indicates that as the particle size decreases, the upconversion red emission and NIR emission components increase in the emission spectra. This phenomenon is attributed to the large ratio of surface area to volume in nanocrystals. This characteristic makes the nanocrystals absorb more OH-, whose vibrational energy is 3 200-3 800 cm(-1). The increase in the OH- number enhances the rate of nonradiative relaxation from Er3+ 4I11/2 to 4I13/2 energy level (energy gap is 3 600 cm(-1)). This nonradiative relaxation process depopulates the 4I11/2 level and makes the green emission weaker. Meanwhile, this process populates the 4I3/2 level and makes the red and NIR emissions stronger. The intensity of 1.5 microm main peak is 1.6 times that of bulk materials. This result has great significance in actual applications of nanophosphors.

  13. NaLa(MoO{sub 4}){sub 2}: RE{sup 3+} (RE{sup 3+} = Eu{sup 3+}, Sm{sup 3+}, Er{sup 3+}/Yb{sup 3+}) microspheres: the synthesis and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Zhiyi [Key Laboratory of Coherent Light, Atomic and Molecular Spectroscopy, Ministry of Education, College of Physics, Jilin University, Changchun 130023 (China); Wang, Zhiying [College of Chemistry and Biology, Beihua University, Jilin 132013 (China); Fu, Linlin; Yang, Xingxing [Key Laboratory of Coherent Light, Atomic and Molecular Spectroscopy, Ministry of Education, College of Physics, Jilin University, Changchun 130023 (China); Fu, Zuoling, E-mail: zlfu@jlu.edu.cn [Key Laboratory of Coherent Light, Atomic and Molecular Spectroscopy, Ministry of Education, College of Physics, Jilin University, Changchun 130023 (China); State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Wu, Zhijian [State Key Laboratory of Rare Earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Jeong, Jung Hyun, E-mail: jhjeong@pknu.ac.kr [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2015-10-15

    The strong green upconversion (UC) emission were observed in various Er{sup 3+}, Yb{sup 3+} co-doped NaLa(MoO{sub 4}){sub 2} samples synthesized via a hydrothermal route. The UC intensity depends on the dopant concentration, and the optimal UC emission was obtained in NaLa(MoO{sub 4}){sub 2}: 0.02Er{sup 3+}/0.10 Yb{sup 3+}. - Highlights: • The NaLa(MoO{sub 4}){sub 2} microspheres doped with Eu{sup 3+}, Sm{sup 3+} and Er{sup 3+}/Yb{sup 3+} were synthesized by a hydrothermal method. • The effects of the EDTA in the initial solution crystal phase and morphology were studied. • The down-conversion luminescence properties of NaLa(MoO{sub 4}){sub 2}: RE{sup 3+} (RE{sup 3+} = Eu{sup 3+}, Sm{sup 3+}) were investigated. • The UC luminescence properties and mechanism of Er{sup 3+}/Yb{sup 3+} co-doped NaLa(MoO{sub 4}){sub 2} was discussed. - Abstract: NaLa(MoO{sub 4}){sub 2}: RE{sup 3+} (RE{sup 3+} = Eu{sup 3+}, Sm{sup 3+}) microspheres have been synthesized at 180 °C via a facile EDTA-mediated hydrothermal route. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), photoluminescence (PL) spectra were employed to characterize the samples. It was found that the amount of EDTA in the initial solution was responsible for crystal phase and shape determination. The effect of Eu{sup 3+} and Sm{sup 3+} doping concentrations on the luminescent intensity was also investigated in details. Furthermore, the up-conversion (UC) emissions have been observed in a series of Er{sup 3+}/Yb{sup 3+} co-doped NaLa(MoO{sub 4}){sub 2} samples. Concentration dependent studies revealed that the optimal composition was realized for a 2% Er{sup 3+} and 10% Yb{sup 3+}-doping concentration.

  14. Up-conversion luminescent properties of La{sub (0.80−x)}VO{sub 4}:Yb{sub x}, Er{sub 0.20} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Dong Hwa; Kang, Deok Hwa [Department of Materials Science and Engineering, Silla University, Busan 617-736 (Korea, Republic of); Yi, Soung Soo, E-mail: ssyi@silla.ac.kr [Department of Materials Science and Engineering, Silla University, Busan 617-736 (Korea, Republic of); Jang, Kiwan [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Jeong, Jung Hyun [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2015-11-15

    Highlights: • A novel green and red emitting LaVO{sub 4}:Yb{sub x}{sup 3+}, Er{sub 0.20}{sup 3+} phosphors were synthesized. • Their structures, luminescent properties have also been investigated. • Major laser transition for Er{sup 3+} ion is {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2} (525 nm). • These results suggest the possibility as photonic devices. - Abstract: Yb{sup 3+}, Er{sup 3+} co-doped LaVO{sub 4} phosphors were synthesized by solid state reaction method. Yb{sup 3+} concentrations were changed from 0.01 to 0.20 mol for the fixed Er{sup 3+} concentration at 0.2 mol. The crystalline structure of samples was investigated by X-ray diffraction (XRD). The composition was investigated by X-ray photoelectron spectroscopy (XPS) analysis. The surface morphology was observed by scanning electron microscope (SEM). The red and green up-conversion emissions were observed in Yb{sup 3+}, Er{sup 3+} co-doped LaVO{sub 4} phosphors under the excitation of 980 nm laser diode. Several emissions in green and red regions of the spectrum were observed near 525 nm, 553 nm and 659 nm radiated by {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2}, and {sup 4}F{sub 3/2} → {sup 4}I{sub 15/2} transitions, respectively.

  15. Magnetic hyperfine interactions on Cd sites of the rare-earth cadmium compounds R Cd (R =Ce , Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er)

    Science.gov (United States)

    Cavalcante, F. H. M.; Leite Neto, O. F. L. S.; Saitovitch, H.; Cavalcante, J. T. P. D.; Carbonari, A. W.; Saxena, R. N.; Bosch-Santos, B.; Pereira, L. F. D.; Mestnik-Filho, J.; Forker, M.

    2016-08-01

    This paper reports the investigation of the magnetic hyperfine field Bh f in a series of rare-earth (R ) cadmium intermetallic compounds R Cd and GdCd2 measured by perturbed angular correlation (PAC) spectroscopy using 111In/111Cd as probe nuclei at Cd sites as well as first-principles calculations of Bh f at Cd sites in the studied compounds. Vapor-solid state reaction of R metals with Cd vapor and the 111In radioisotope was found to be an appropriate route of doping rare-earth cadmium compounds with the PAC probe 111In/111Cd. The observation that the hyperfine parameters depend on details of the sample preparation provides information on the phase preference of diffusing 111In in the rare-earth cadmium phase system. The 111Cd hyperfine field has been determined in the compounds R Cd for the R constituents Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er, in several cases as a function of temperature. For most R constituents, the temperature dependence Bh f(T ) of 111Cd:R Cd is consistent with ferromagnetic order of the compound. DyCd, however, presents a remarkable anomaly: a finite magnetic hyperfine field is observed only in the temperature interval 35 K ≤ T ≤ 80 K which indicates a transition from ferromagnetic order to a spin arrangement where all 4 f -induced contributions to the magnetic hyperfine field at the Cd site cancel. First-principles calculation results for DyCd show that the (π , π , 0) antiferromagnetic configuration is energetically more favorable than the ferromagnetic. The approach used in the calculations to simulate the R Cd system successfully reproduces the experimental values of Bh f at Cd sites and shows that the main contribution to Bh f comes from the valence electron polarization. The de Gennes plot of the hyperfine field Bh f of 111Cd:R Cd vs the 4 f -spin projection (g -1 )J reflects a decrease of the strength of indirect 4 f -4 f exchange across the R series. Possible mechanisms are discussed and the experimental results indicate that

  16. Synthesis,structure and catalytic activity of complexes [Ln(EDBP)2(DME)Na(DME)3](Ln=Er,Yb,Sm) for ring-opening polymerization of ε-caprolactone

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Discrete ion-pair complexes [Ln(EDBP)2(DME)Na(DME)3] [Ln=Er (1), Yb (2), Sm (3)] have been synthesized by the reaction between sodium salt of 2,2’-ethylidene-bis(4,6-di-tert-butylphenol)(EDBPH2) and Ln(BH4)3·3THF (Ln=Er, Yb, Sm) followed by centrifugation and recrystalization. The complexes were characterized by elemental analysis and FT-IR, and the bonding model of these compounds was confirmed by X-ray single crystal diffraction for complex 1. It was found that four O atoms in two biphenol ligands as well as two O atoms in one ethylene glycol dimethyl ether (DME) molecule connect to the center rare earth metal atom, while sodium exists as counterpart cation to balance the charge. Complexes 1―3 can all be used as single component initiators for the ring-opening polymerization of ε-caprolactone.

  17. Watt-level, all-fiber, ultrafast Er/Yb-codoped double-clad fiber laser mode-locked by reduced graphene oxide interacting with a weak evanescent field

    CERN Document Server

    Gao, Lei; Li, Yujia

    2015-01-01

    We propose a Watt-level, all-fiber, ultrafast Er/Yb-codoped double-clad fiber laser passively mode-locked by reduced graphene oxide (rGO) interacting with a weak evanescent field of photonic crystal fiber (PCF). The rGO solution is filled into the cladding holes of the PCF based on total reflection, and after evaporation, the rGO flakes bear only 1/107 of the total energy in laser system, which enhances the thermal damage threshold and decreases the accumulated nonlinearity. By incorporating the saturable absorber into an Er/Yb-codoped fiber ring cavity, stable conventional soliton with a duration of 573 fs is generated, and a average output power up to 1.14 W is obtained.

  18. Charge transfer excitation of trivalent rare earth ions Sm/sup 3+/, Eu/sup 3+/, Gd/sup 3+/, Ho/sup 3+/, Er/sup 3+/ and Yb/sup 3+/ emission in BaFCl crystals

    Energy Technology Data Exchange (ETDEWEB)

    Su, M.Z.; Sun, X.P.

    1987-01-01

    The charge transfer type excitation spectra of trivalent rare earth ions Sm/sup 3+/, Eu/sup 3+/, Gd/sup 3+/, Ho/sup 3+/, Er/sup 3+/ and Yb/sup 3+/ emission in BaFCl crystals have been studied. The charge transfer type emissions of Ho/sup 3+/, Er/sup 3+/ and Yb/sup 3+/ in BaFCl have also been observed in addition to that of Eu/sup 3+/. The energy of charge transfer band of these RE/sup 3+/ ions were estimated experimentally and also calculated by Jorgensen's refined electron spin-pairing energy theory. Both the experimental and calculated values coincide well.

  19. Thermal Stability and Infrared-To Upconversion Emissions of Er3+/Yb3+ Co-Doped 70GeO2-20PbO-10K2O Glasses

    Science.gov (United States)

    Ahmed, Samah M.; Shaltout, I.; Badr, Y.

    2011-06-01

    Er3+/Yb3+ co-doped potassium-lead-germanate (70GeO2-20PbO-10K2O) glasses with a fixed concentration of Er3+ ions (0.5 mol. %) and different concentrations of Yb3+ ions (0, 0.5, 1.5, and 2.5 mol. %), have been synthesized by the conventional melting and quenching method. The structure and vibrational modes of the glass network were investigated by the infrared absorption and Raman spectroscopy. The thermal behavior of all glass samples was investigated by the differential thermal analysis. Infrared-to-visible frequency upconversion process was investigated in all glasses. Intense green and red upconversion emission bands centered at around 532, 546, and 655 nm were observed, underallglasses.Intense excitation at 980 nm of diode laser at room temperature. The dependence of these emissions on the excitation power was investigated.

  20. Structure-property relations in new fluorophosphate glasses singly- and co-doped with Er{sup 3+} and Yb{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Gonçalves, Tássia S.; Moreira Silva, Raphaell J.; Oliveira Junior, Marcos de; Ferrari, Cynthia R. [Physics Institute of São Carlos, University of São Paulo, São Carlos, SP 13566-590 (Brazil); Poirier, Gäel Y. [Science and Technology Institute, Federal University of Alfenas, Poços de Caldas, MG 37715-400 (Brazil); Eckert, Hellmut, E-mail: eckert@ifsc.usp.br [Physics Institute of São Carlos, University of São Paulo, São Carlos, SP 13566-590 (Brazil); Physical Chemistry Institute, Westfälische Wilhelms Universität Münster, Münster D-48149 (Germany); Camargo, Andrea S.S. de, E-mail: andreasc@ifsc.usp.br [Physics Institute of São Carlos, University of São Paulo, São Carlos, SP 13566-590 (Brazil)

    2015-05-01

    Rare earth (RE{sup 3+})-doped fluorophosphate glasses are among the most promising candidates for high-efficiency laser generation in the near-infrared spectral region. By proper choice of composition, these materials can combine the advantages of fluorides (low phonon energies, low refractive indices, extensive optical window, low hygroscopicity) and of oxides (high chemical and mechanical stability and high dopant solubility), resulting in enhancement of the RE{sup 3+} emissive properties. In this work, we present the synthesis and structural/spectroscopic investigation of new glasses with composition 25BaF{sub 2}25SrF{sub 2}(30-x)Al(PO{sub 3}){sub 3}xAlF{sub 3}(20-z)YF{sub 3}:zREF{sub 3}, where x = 20 or 15, RE = Er{sup 3+} and/or Yb{sup 3+}, z = 0.25–5.0 mol%. Results indicate considerable improvement of the emissive properties of both ions when compared to phosphate or even other fluorophosphate host compositions. Long excited state lifetimes (τ = 10 ms for the Er{sup 3+} level {sup 4}I{sub 13/2}, and τ = 1.3 ms for the Yb{sup 3+} level {sup 2}F{sub 5/2}) imply high fluorescence quantum efficiencies η (up to 85% for both ions). Structural characterization by Raman and multinuclear solid state NMR spectroscopies indicate that the metaphosphate-type chain structure of the Al(PO{sub 3}){sub 3} vitreous framework is partially depolymerized and dominated by Q{sup (0)} and Q{sup (1)} units crosslinked by six-coordinate Al species. As revealed by {sup 27}Al{"3"1P} rotational echo double resonance (REDOR) NMR results the average local aluminum environment of the x = 20 sample comprises 1.6 phosphate and 4.4 fluoride species. These results indicate a clear bonding preference between aluminum and phosphorus, which is consistent with the desired dominance of fluoride species in the local environment of the rare earth and alkaline earth atoms in these glasses. - Highlights: • New fluorophosphate glass composition with excellent photophysical properties.

  1. Near-infrared photocatalysts of BiVO4/CaF2:Er3+, Tm3+, Yb3+ with enhanced upconversion properties

    Science.gov (United States)

    Huang, Shouqiang; Zhu, Nanwen; Lou, Ziyang; Gu, Lin; Miao, Chen; Yuan, Haiping; Shan, Aidang

    2014-01-01

    Upconversion photocatalysts have the potential to absorb the near-infrared (NIR) light in solar energy and improve the photocatalytic performance. A hierarchical upconversion photocatalyst of BiVO4 (BVO)/CaF2:Er3+, Tm3+, Yb3+ (CF) combined with the narrow-band semiconductor of BVO and the luminescence agent of CF to enhance upconversion properties was synthesized via the hydrothermal method. The CF particles were deposited homogeneously on the surface of the BVO/CF composite with regular dendritic structure, which led to efficient upconversion emissions. The upconversion emission intensity of the BVO/CF composite was 8 times higher than that of pure CF, through tailoring the crystal symmetry of lanthanide ions by Bi3+ ions. The upconverted ultraviolet (361 and 379 nm), violet (408 nm), and blue (485 nm) light was able to excite BVO for photocatalysis in BVO/CF under NIR irradiation, which improved the degradation rate of methyl orange (MO).Upconversion photocatalysts have the potential to absorb the near-infrared (NIR) light in solar energy and improve the photocatalytic performance. A hierarchical upconversion photocatalyst of BiVO4 (BVO)/CaF2:Er3+, Tm3+, Yb3+ (CF) combined with the narrow-band semiconductor of BVO and the luminescence agent of CF to enhance upconversion properties was synthesized via the hydrothermal method. The CF particles were deposited homogeneously on the surface of the BVO/CF composite with regular dendritic structure, which led to efficient upconversion emissions. The upconversion emission intensity of the BVO/CF composite was 8 times higher than that of pure CF, through tailoring the crystal symmetry of lanthanide ions by Bi3+ ions. The upconverted ultraviolet (361 and 379 nm), violet (408 nm), and blue (485 nm) light was able to excite BVO for photocatalysis in BVO/CF under NIR irradiation, which improved the degradation rate of methyl orange (MO). Electronic supplementary information (ESI) available: Additional tables and figures. See

  2. Near infrared and visible luminescence from xerogels covalently grafted with lanthanide [Sm(3+), Yb(3+), Nd(3+), Er(3+), Pr(3+), Ho(3+)] β-diketonate derivatives using visible light excitation.

    Science.gov (United States)

    Sun, Lining; Qiu, Yannan; Liu, Tao; Zhang, Jin Z; Dang, Song; Feng, Jing; Wang, Zhijuan; Zhang, Hongjie; Shi, Liyi

    2013-10-09

    A series of ternary lanthanide β-diketonate derivatives covalently bonded to xerogels (named as Ln-DP-xerogel, Ln = Sm, Yb, Nd, Er, Pr, Ho) by doubly functionalized alkoxysilane (dbm-Si) was synthesized in situ via a sol-gel process. The properties of these xerogel materials were investigated by Fourier-transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), diffuse reflectance (DR) spectroscopy, thermogravimetric analyses, and fluorescence spectroscopy. The data and analyses suggest that the lanthanide derivatives have been covalently grafted to the corresponding xerogels successfully. Of importance here is that, after excitation with visible light (400-410 nm), the xerogels all show characteristic visible (Sm(3+)) as well as near-infrared (NIR; Sm(3+), Yb(3+), Nd(3+), Er(3+), Pr(3+), Ho(3+)) luminescence of the corresponding Ln(3+) ions, which is attributed to the energy transfer from the ligands to the Ln(3+) ions via an antenna effect. Exciting with visible light is advantageous over UV excitation. Furthermore, to the best of our knowledge, it is the first observation of NIR luminescence with visible light excitation from xerogels covalently bonded with the Sm(3+), Pr(3+), and Ho(3+) derivatives. Compared to lanthanide complexes (Ln = Er, Nd, Yb) functionalized periodic mesoporous organosilica (PMO) materials that exhibit similar optical properties reported in our previous work, the Ln-DP-xerogel (Ln = Sm, Yb, Nd, Er, Pr, Ho) in this case offer advantages in terms of ease of synthesis and handling and potentially low cost for emerging technological applications. Development of near-infrared luminescence of the lanthanide materials with visible light excitation is of strong interest to emerging applications such as chemosensors, laser systems, and optical amplifiers.

  3. NIR luminescent Er{sup 3+}/Yb{sup 3+} co-doped SiO{sub 2}-ZrO{sub 2} nanostructured planar and channel waveguides: Optical and structural properties

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Cesar dos Santos [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto/SP (Brazil); Ferrari, Jefferson Luis [Grupo de Pesquisa em Quimica de Materiais - (GPQM), Departamento de Ciencias Naturais, Universidade Federal de Sao Joao Del Rei, Campus Dom Bosco, Praca Dom Helvecio, 74, 36301-160, Sao Joao Del Rei, MG (Brazil); Oliveira, Drielly Cristina de [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto/SP (Brazil); Maia, Lauro June Queiroz [Grupo Fisica de Materiais, Instituto de Fisica, UFG, Campus Samambaia, Caixa Postal 131, 74001-970, Goiania/GO (Brazil); Gomes, Anderson Stevens Leonidas [Departamento de Fisica, Universidade Federal de Pernambuco, Cidade Universitaria, Recife/PE, 50670-901 (Brazil); Ribeiro, Sidney Jose Lima [Laboratorio de Materiais Fotonicos, Instituto de Quimica, UNESP, Caixa Postal 355, 14801-970, Araraquara/SP (Brazil); and others

    2012-09-14

    Optical and structural properties of planar and channel waveguides based on sol-gel Er{sup 3+} and Yb{sup 3+} co-doped SiO{sub 2}-ZrO{sub 2} are reported. Microstructured channels with high homogeneous surface profile were written onto the surface of multilayered densified films deposited on SiO{sub 2}/Si substrates by a femtosecond laser etching technique. The densification of the planar waveguides was evaluated from changes in the refractive index and thickness, with full densification being achieved at 900 Degree-Sign C after annealing from 23 up to 500 min, depending on the ZrO{sub 2} content. Crystal nucleation and growth took place together with densification, thereby producing transparent glass ceramic planar waveguides containing rare earth-doped ZrO{sub 2} nanocrystals dispersed in a silica-based glassy host. Low roughness and crack-free surface as well as high confinement coefficient were achieved for all the compositions. Enhanced NIR luminescence of the Er{sup 3+} ions was observed for the Yb{sup 3+}-codoped planar waveguides, denoting an efficient energy transfer from the Yb{sup 3+} to the Er{sup 3+} ion. Highlights: Black-Right-Pointing-Pointer Sol-gel high NIR luminescent nanostructured planar and channel waveguides. Black-Right-Pointing-Pointer Microstructured channels written by a femtosecond laser etching technique. Black-Right-Pointing-Pointer Transparent glass ceramic with rare earth-doped ZrO{sub 2} nanocrystals in a silica host. Black-Right-Pointing-Pointer Enhanced NIR luminescence, efficient energy transfer from the Yb{sup 3+} to the Er{sup 3+} ion. Black-Right-Pointing-Pointer New planar channel waveguides to be applied as EDWA in the C telecommunication band.

  4. Covalently-bonded grafting of [Ln3(Benzimidazole)4]-arrayed (Ln = Tb, Nd, Yb or Er) complex monomers into PNBE (poly(norbornene)) with highly luminous color-purity green-light or efficient NIR luminescence

    Science.gov (United States)

    Liu, Lin; Fu, Guorui; Feng, Heini; Guan, Jiaqing; Li, Fengping; Lü, Xingqiang; Wong, Wai-Kwok; Jones, Richard A.

    2017-07-01

    Within series of Ln3-grafted polymers Poly({[Ln3(L)4(NO3)6]·(NO3)·(H3O)2}-co-NBE) (Ln = La, 1; Ln = Eu, 2; Ln = Tb, 3; Ln = Nd, 4; Ln = Yb, 5; Ln = Er, 6 or Ln = Gd, 7) obtained from ring-opening metathesis polymerization (ROMP) of norbornene (NBE) with each of allyl-functionalized complex monomers {[Ln3(L)4(NO3)6]·(NO3)·(H3O)2} (HL = 4-allyl-2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol), PNBE-assisted effective energy transfer renders Poly(3-co-NBE) Tb3+-centered highly luminous color-purity green-light with an attractive quantum yield of 87% and efficient near-infrared (NIR) luminescence (ΦNdL = 0.61%; ΦYbL = 1.47% and ΦErL = 0.03%) for Nd3+-, Yb3+- or Er3+-grafted polymers.

  5. Raman and Fluorescence Spectroscopy of CeO2, Er2O3, Nd2O3, Tm2O3, Yb2O3, La2O3, and Tb4O7

    Directory of Open Access Journals (Sweden)

    Jianlan Cui

    2015-01-01

    Full Text Available To better understand and ascertain the mechanisms of flotation reagent interaction with rare earth (RE minerals, it is necessary to determine the physical and chemical properties of the constituent components. Seven rare earth oxides (CeO2, Er2O3, Nd2O3, Tm2O3, Yb2O3, La2O3, and Tb4O7 that cover the rare earth elements (REEs from light to heavy REEs have been investigated using Raman spectroscopy. Multiple laser sources (wavelengths of 325 nm, 442 nm, 514 nm, and 632.8 nm for the Raman shift ranges from 100 cm−1 to 5000 cm−1 of these excitations were used for each individual rare earth oxide. Raman shifts and fluorescence emission have been identified. Theoretical energy levels for Er, Nd, and Yb were used for the interpretation of fluorescence emission. The experimental results showed good agreement with the theoretical calculation for Er2O3 and Nd2O3. Additional fluorescence emission was observed with Yb2O3 that did not fit the reported energy level diagram. Tb4O7 was observed undergoing laser induced changes during examination.

  6. Thermoluminescence and optically stimulated luminescence properties of nanocrystalline Er{sup 3+} and Yb{sup 3+} doped Y{sub 3}Al{sub 5}O{sub 12} exposed to {beta}-rays

    Energy Technology Data Exchange (ETDEWEB)

    RodrIguez, R A [Universidad de Guadalajara en Lagos, Lagos de Moreno, Jalisco, 47460 (Mexico); Rosa, E de la [Centro de Investigaciones en Optica, A.P. 1-948, Leon, Gto. 37150 (Mexico); Salas, P [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, C.P. 07730, Mexico, D. F. (Mexico); Melendrez, R [Centro de Investigacion en Fisica, Universidad de Sonora, PO Box 5-088, Hermosillo, Sonora, 83190 (Mexico); Barboza-Flores, M [Centro de Investigacion en Fisica, Universidad de Sonora, PO Box 5-088, Hermosillo, Sonora, 83190 (Mexico)

    2005-11-07

    The thermoluminescence (TL) and optically stimulated luminescence (OSL) characterization of Er{sup 3+} and Yb{sup 3+} doped Y{sub 3}Al{sub 5}O{sub 12} nanocrystalline samples prepared by the precipitation process and exposed to {beta}-rays are discussed. The TL as well as the OSL were two orders of magnitude higher in Er{sup 3+} doped than in Yb{sup 3+} specimens. The charge trapping and the radiative thermally stimulated recombination processes in Y{sub 3}Al{sub 5}O{sub 12} : Er{sup 3+} involve four trapping states at 166, 243, 342 and 424 deg. C, but just two trapping levels at 219 and 413 deg. C for Y{sub 3}Al{sub 5}O{sub 12} : Yb{sup 3+} at a heating rate of 10 deg. C s{sup -1}. The photostimulation with 470 nm light causes in both phosphors a radiative recombination of the optically free charge carriers belonging to the same trapping states. The TL and the OSL as a function of radiation dose behaviour were linear in the 10-100 Gy dose range. The results provide evidence of the potential uses of these materials in radiation storage and dosimeter devices.

  7. White light generation via up-conversion and blue tone in Er3+/Tm3+/Yb3+-doped zinc-tellurite glasses

    Science.gov (United States)

    Rivera, V. A. G.; Ferri, F. A.; Nunes, L. A. O.; Marega, E.

    2017-05-01

    Yb3+, Er3+ and Tm3+ triply doped zinc-tellurite glass have been prepared containing up to 3.23 wt% of rare-earth ion oxides, were characterized by absorption spectroscopy, excitation, emission and up-conversion spectra. Transparent and homogeneous glasses have been produced, managing the red, green and blue emission bands, in order to generate white light considering the human eye perception. The energy transfer (resonant or non-resonant) between those rare-earth ions provides a color balancing mechanism that maintains the operating point in the white region, generating warm white light, cool white light and artificial daylight through the increase of the 976/980 nm diode laser excitation power from 4 to 470 mW. A light source at 4000 K is obtained under the excitation at 980 nm with 15 mW, providing a white light environment that is comfortable to the human eye vision. The spectroscopic study presented in this work describes the white light generation by the triply-doped zinc-tellurite glass, ranging from blue, green and red, by controlling the laser excitation power and wavelength at 976/980 nm. Such white tuning provokes healthy effects on human health throughout the day, especially the circadian system.

  8. Fabrication of Au-Ag nanocage@NaYF4@NaYF4:Yb,Er Core-Shell Hybrid and its Tunable Upconversion Enhancement

    Science.gov (United States)

    Chen, Xu; Zhou, Donglei; Xu, Wen; Zhu, Jinyang; Pan, Gencai; Yin, Ze; Wang, He; Zhu, Yongsheng; Shaobo, Cui; Song, Hongwei

    2017-01-01

    Localized electric filed enhancement by surface plasmon resonance (SPR) of noble metal nanoparticles is an effective method to amplify the upconversion luminescence (UCL) strength of upconversion nanoparticles (UCNPs), whereas the highly effective UCL enhancement of UCNPs in colloids has not been realized until now. Here, we designed and fabricated the colloidal Au-Ag nanocage@NaYF4@NaYF4:Yb,Er core-shell hybrid with different intermediate thickness (NaYF4) and tunable SPR peaks from visible wavelength region to NIR region. After the optimization of the intermediate spacer thickness (~7.5 nm) of NaYF4 NPs and the SPR peak (~950 nm) of noble metal nanoparticles, an optimum enhancement as high as ~25 folds was obtained. Systematic investigation indicates that UCL enhancement mainly originates from the influence of the intermediate spacer and the coupling of Au-Ag nanocages with the excitation electromagnetic field of the UCNPs. Our findings may provide a new thinking on designing highly effective metal@UCNPs core-shell hybrid in colloids.

  9. DNA Probe and Cleavage Studies Based on the Interaction between DNA and Yb, Er Complexes of 2-[(Trifluoroaceto)aceto]thinophene-piperidine Ligands

    Institute of Scientific and Technical Information of China (English)

    YIN Caixia; HUO Fangjun; WU Yanbo; LIU Yanlin; YANG Pin

    2009-01-01

    Two kinds of Ln complexes of [Ln(TTA)4]·Hp (Ln=Yb or Er, TrA=2-[(Trifluoroaceto)aceto]thinophene, HP =piperidine) have been synthesized and characterized, and their DNA-binding properties investigated using UV spectra, fluorescent spectra, viscometry and molecular modeling. The results show that they can intercalate into the double helices of DNA. More important thing is that their fluorescence intensity can be enhanced by DNA, thererfore, a sensitive fluorescence method for the determination of DNA may be developed. The cleavage reaction on plasmid DNA has been monitored by agarose gel electrophoresis. Interestingly, the complexes can cleave circular plasmid pBR322 DNA at pH=7.2 and 37 ℃. In addition, BDNPP [bis(2,4-dinitropheny1)-phosphate] was chosen as a model compound to further study their cleavage mechanism of pBR322 DNA. From the first-order kinetics equation, it was proved indirectly that the mechanism may be a hydrolytic cleavage.

  10. In vitro and in vivo investigations of upconversion and NIR emitting Gd₂O₃:Er³⁺,Yb³⁺ nanostructures for biomedical applications.

    Science.gov (United States)

    Hemmer, Eva; Takeshita, Hiroyuki; Yamano, Tomoyoshi; Fujiki, Takanori; Kohl, Yvonne; Löw, Karin; Venkatachalam, Nallusamy; Hyodo, Hiroshi; Kishimoto, Hidehiro; Soga, Kohei

    2012-10-01

    The use of an "over 1000-nm near-infrared (NIR) in vivo fluorescence bioimaging" system based on lanthanide containing inorganic nanostructures emitting in the visible and NIR range under 980-nm excitation is proposed. It may overcome problems of currently used biomarkers including color fading, phototoxicity and scattering. Gd(2)O(3):Er(3+),Yb(3+) nanoparticles and nanorods showing upconversion and NIR emission are synthesized and their cytotoxic behavior is investigated by incubation with B-cell hybridomas and macrophages. Surface modification with PEG-b-PAAc provides the necessary chemical durability reducing the release of toxic Gd(3+) ions. NIR fluorescence microscopy is used to investigate the suitability of the nanostructures as NIR-NIR biomarkers. The in vitro uptake of bare and modified nanostructures by macrophages is investigated by confocal laser scanning microscopy. In vivo investigations revealed nanostructures in liver, lung, kidneys and spleen a few hours after injection into mice, while most of the nanostructures have been removed from the body after 24 h.

  11. NIR-induced highly sensitive detection of latent finger-marks by NaYF4:Yb,Er upconversion nanoparticles in a dry powder state

    Science.gov (United States)

    Wang, Meng; Li, Ming; Yang, Mingying; Zhang, Xiaomei; Yu, Aoyang; Zhu, Ye; Qiu, Penghe; Mao, Chuanbin

    2016-01-01

    The most commonly found fingermarks at crime scenes are latent and, thus, an efficient method for detecting latent fingermarks is very important. However, traditional developing techniques have drawbacks such as low detection sensitivity, high background interference, complicated operation, and high toxicity. To tackle this challenge, we employed fluorescent NaYF4:Yb,Er upconversion nanoparticles (UCNPs), which can fluoresce visible light when excited by 980 nm human-safe near-infrared light, to stain the latent fingermarks on various substrate surfaces. The UCNPs were successfully used as a novel fluorescent label for the detection of latent fingermarks with high sensitivity, low background, high efficiency, and low toxicity on various substrates including non-infiltrating materials (glass, marble, aluminum alloy sheets, stainless steel sheets, aluminum foils, and plastic cards), semi-infiltrating materials (floor leathers, ceramic tiles, wood floor, and painted wood), and infiltrating materials such as various types of papers. This work shows that UCNPs are a versatile fluorescent label for the facile detection of fingermarks on virtually any material, enabling their practical applications in forensic sciences.

  12. Up-Conversion Y2O3:Yb(3+),Er(3+) Hollow Spherical Drug Carrier with Improved Degradability for Cancer Treatment.

    Science.gov (United States)

    Ge, Kun; Zhang, Cuimiao; Sun, Wentong; Liu, Huifang; Jin, Yi; Li, Zhenhua; Liang, Xing-Jie; Jia, Guang; Zhang, Jinchao

    2016-09-28

    The rare earth hollow spheres with up-conversion luminescence properties have shown potential applications in drug delivery and bioimaging fields. However, there have been few reports for the degradation properties of rare earth oxide drug carriers. Herein, uniform and well-dispersed Y2O3:Yb(3+),Er(3+) hollow spheres (YOHSs) have been fabricated by a general Pechini sol-gel process with melamine formaldehyde colloidal spheres as template. The novel YOHSs with up-conversion luminescence has good drug loading amount and drug-release efficiency; moreover, it exhibits pH-responsive release patterns. In particular, the YOHSs sample exhibits low cytotoxicity and excellent degradable properties in acid buffer. After the sample was loaded with anticancer drug doxorubicin (DOX), the antitumor result in vitro indicates that YOHS-DOX might be effective in cancer treatment. The animal imaging test also reveals that the YOHSs drug carrier can be used as an outstanding luminescent probe for bioimaging in vivo application prospects. The results suggest that the degradable drug carrier with up-conversion luminescence may enhance the delivery efficiency of drugs and improve the cancer therapy in clinical applications.

  13. Utilization of visible to NIR light energy by Yb+3, Er+3 and Tm+3 doped BiVO4 for the photocatalytic degradation of methylene blue

    Science.gov (United States)

    Regmi, Chhabilal; Kshetri, Yuwaraj K.; Ray, Schindra Kumar; Pandey, Ramesh Prasad; Lee, Soo Wohn

    2017-01-01

    Lanthanide-doped BiVO4 semiconductors with efficient photocatalytic activities over a broad range of the solar light spectrum have been synthesized by the microwave hydrothermal method using ethylenediaminetetraacetic acid (EDTA). The structural, morphological, and optical properties of the as-synthesized samples were evaluated by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray powder diffraction (XRD), Raman spectroscopy, FT-IR spectroscopy, UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence spectroscopy (PL). The chemical compositions were analyzed by X-ray photoelectron spectroscopy (XPS). The toxicity of the samples was measured using Mus musculus skin melanoma cells (B16-F10 (ATCC CRL-6475™)) and were found to be nontoxic for human cells. The photocatalytic efficiency of the prepared samples was evaluated by methylene blue (MB) degradation. The best photocatalytic activity was shown by BiVO4 with 6:3:3 mol percentage of Yb+3:Er+3:Tm+3 in all solar light spectrum. The synthesized samples possess low band gap energy and a hollow structure suitable for the better photocatalytic activity. The observed NIR photoactivity supports that the upconversion mechanism is involved in the overall photocatalytic process. Therefore, this approach provides a better alternative upconversion material for integral solar light absorption.

  14. Fabrication of Au-Ag nanocage@NaYF4@NaYF4:Yb,Er Core-Shell Hybrid and its Tunable Upconversion Enhancement

    Science.gov (United States)

    Chen, Xu; Zhou, Donglei; Xu, Wen; Zhu, Jinyang; Pan, Gencai; Yin, Ze; Wang, He; Zhu, Yongsheng; Shaobo, Cui; Song, Hongwei

    2017-01-01

    Localized electric filed enhancement by surface plasmon resonance (SPR) of noble metal nanoparticles is an effective method to amplify the upconversion luminescence (UCL) strength of upconversion nanoparticles (UCNPs), whereas the highly effective UCL enhancement of UCNPs in colloids has not been realized until now. Here, we designed and fabricated the colloidal Au-Ag nanocage@NaYF4@NaYF4:Yb,Er core-shell hybrid with different intermediate thickness (NaYF4) and tunable SPR peaks from visible wavelength region to NIR region. After the optimization of the intermediate spacer thickness (~7.5 nm) of NaYF4 NPs and the SPR peak (~950 nm) of noble metal nanoparticles, an optimum enhancement as high as ~25 folds was obtained. Systematic investigation indicates that UCL enhancement mainly originates from the influence of the intermediate spacer and the coupling of Au-Ag nanocages with the excitation electromagnetic field of the UCNPs. Our findings may provide a new thinking on designing highly effective metal@UCNPs core-shell hybrid in colloids. PMID:28106128

  15. Formation of upconversion nanoparticles of 18%Yb:1%Er:NAYF4 by ultra-short pulse laser ablation in water

    Science.gov (United States)

    Gemini, Laura; Hernandez, Marie-Caroline; Kling, Rainer

    2016-03-01

    Pulsed laser ablation in liquid (PLAL) is nowadays gaining popularity as innovative, reliable and efficient technique to produce high-purity nanoparticles (NPs) of many inorganic and organic materials. In this context, attention has been recently focused on luminescent up-conversion NPs (UCNPs) which, being characterized by sharp emission bands in ultraviolet (UV)-to-near-infrared (NIR) range upon NIR irradiation, are in fact of great interest in many biological and biomedical applications. Moreover, with respect to organic dyes NPs and quantum dots, UCNPs show less toxicity, increased chemical stability, long-lifetime decays and lack of photo-bleaching. Our research focuses on generation of UCNPs of rare earth lanthanide-doped crystalline material, namely 18%Yb:1%Er:NAYF4, by PLAL in water. It is well known that optical properties of NPs strongly depend on their features, as for instance size and shape, which in turn may be controlled by laser ablation parameters. Therefore, two different laser sources are used for the ablation processes in order to find the set of laser parameter, i.e. pulse duration, laser fluence and repetition rate, for which the luminescence of UPNPs is optimized: (i) Amplitude Satsuma HP3 system: 330 fs pulse duration, 1030 wavelength and (ii) Eolite Hegoa system: 50 ps pulse duration, 1030 nm wavelength. UCNPs are finally characterized by spectrophotometer analyses to define emission range and intensity under NIR light and by transmission electron microscopy (TEM) to determine their size and shape.

  16. pH value manipulated phase transition, microstructure evolution and tunable upconversion luminescence in Yb(3+)-Er(3+) codoped LiYF4/YF3 nanoparticles.

    Science.gov (United States)

    Ye, Song; Hu, Rongxuan; Jiang, Nan; Wang, Huiyun; Wang, Deping

    2015-09-21

    The pH value plays an important role in controlling the crystallization process and microstructure of the final products in the synthesis of nanocrystals with a solvothermal method. This work reported the effect of the mother solution pH value on the precipitation of LiYF4 and YF3 nanoparticles, as well as the microstructure evaluation of YF3 from a bowknot-like to spindle-like shape. Spectroscopy study suggests that there is strong correlation between the upconversion emission properties of the Yb(3+)-Er(3+) couple and the phase and the microstructure of the host. The strongest emissions and lowest red-to-green ratio are observed in the bowknot-like YF3 nanocrystals with the largest open ends. Further spectral investigation indicates that the phase and microstructure dependent upconversion properties are associated with the upconversion efficiency. The present study is of great importance in the design and synthesis of rare earth ion doped nanocrystals with tunable upconversion properties.

  17. Infrared and Raman spectra of tris(dipivaloylmethanato) lanthanides, Ln(thd)3 (Ln = La, Nd, Eu, Gd, Tb, Ho, Er, Tm, Yb, Lu)

    Science.gov (United States)

    Belova, Natalya V.; Sliznev, Valery V.; Christen, Dines

    2017-03-01

    The infrared and Raman vibrational spectra of the series of solid tris(dipivaloylmethanato) lanthanides, Ln(thd)3 (Ln = La, Nd, Eu, Gd, Tb, Ho, Er, Tm, Yb, Lu), have been recorded at room temperature over wide ranges (4000-50 cm-1 and 3500-80 cm-1, respectively). The experimental spectra obtained in the present study were successfully assigned based on the quantum chemical calculations (DFT/PBE0) performed for the monomer Ln(thd)3 molecules. The experimental vibrational spectra for all complexes studied are rather similar as are the theoretical simulations. The data analysis shows that the main contributions to vibrational modes arise from the vibrations of the ligand possessing practically the same geometry for all complexes. According to the calculation results the structure of the coordination polyhedron is increasingly distorted in the series from La(thd)3 to Lu(thd)3. Although the contributions of the polyhedron vibrations in vibrational modes are not predominant, there is rise in the frequencies associated with vibrations of the coordination polyhedron LnO6 in this series. This increase has been explained by the concept of lanthanide contraction.

  18. Synthesis and functionalization of NaGdF4:Yb,Er@NaGdF4 core-shell nanoparticles for possible application as multimodal contrast agents.

    Science.gov (United States)

    Baziulyte-Paulaviciene, Dovile; Karabanovas, Vitalijus; Stasys, Marius; Jarockyte, Greta; Poderys, Vilius; Sakirzanovas, Simas; Rotomskis, Ricardas

    2017-01-01

    Upconverting nanoparticles (UCNPs) are promising, new imaging probes capable of serving as multimodal contrast agents. In this study, monodisperse and ultrasmall core and core-shell UCNPs were synthesized via a thermal decomposition method. Furthermore, it was shown that the epitaxial growth of a NaGdF4 optical inert layer covering the NaGdF4:Yb,Er core effectively minimizes surface quenching due to the spatial isolation of the core from the surroundings. The mean diameter of the synthesized core and core-shell nanoparticles was ≈8 and ≈16 nm, respectively. Hydrophobic UCNPs were converted into hydrophilic ones using a nonionic surfactant Tween 80. The successful coating of the UCNPs by Tween 80 has been confirmed by Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy (SEM), powder X-ray diffraction (XRD), photoluminescence (PL) spectra and magnetic resonance (MR) T1 relaxation measurements were used to characterize the size, crystal structure, optical and magnetic properties of the core and core-shell nanoparticles. Moreover, Tween 80-coated core-shell nanoparticles presented enhanced optical and MR signal intensity, good colloidal stability, low cytotoxicity and nonspecific internalization into two different breast cancer cell lines, which indicates that these nanoparticles could be applied as an efficient, dual-modal contrast probe for in vivo bioimaging.

  19. Effect of nanocrystals on up-conversion luminescence of Er3+,Yb3+ co-doped glass-ceramics

    Institute of Scientific and Technical Information of China (English)

    Hua Yu; Lijuan Zhao; Jie Meng; Qin Liang; Xuanyi Yu; Baiquan Tang; Jingjun Xu

    2005-01-01

    @@ Different up-conversion luminescent spectra of Er3+ ions were observed in the oxyfluoride glass-ceramics.The ratio of two fluorides in the original compositions was modified in order to form different nanocrystals.The intensity of up-conversion luminescence increased sharply when the ratio of PbF2 and CdF2 was 40:10.The data of differential thermal analysis and X-ray diffraction were used to explain the optimization fluoride ratio. The intensity of up-conversion luminescence is not only decided by the crystallizability but also mainly related with the stoichiometric proportion of fluoride nanocrystals in the glass-ceramics.

  20. Peculiarity of component interaction in {l_brace}Y, Dy{r_brace}-Mn-Sn ternary systems

    Energy Technology Data Exchange (ETDEWEB)

    Romaka, V.V. [Department of Materials Engineering and Applied Physics, Lviv Polytechnic National University, Ustyyanovycha Str. 5, 79013 Lviv (Ukraine); Konyk, M. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Romaka, L., E-mail: romakal@franko.lviv.ua [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Pavlyuk, V. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Jan Dlugosz University, Institute of Chemistry, Environmental Protection and Biotechnology, al. Armii Krajowej 13/15, 42200 Czestochowa (Poland); Ehrenberg, H. [Institute for Complex Materials, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden (Germany); Tkachuk, A. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine)

    2011-07-14

    Highlights: > {l_brace}Y, Dy{r_brace}-Mn-Sn ternary systems at 770 K are characterized by formation of stannides with general compositions RMn{sub 6}Sn{sub 6} and R{sub 4}Mn{sub 4}Sn{sub 7}. > The crystal structure of YMn{sub 6}Sn{sub 6} was determined by single crystal and powder diffraction methods. > Structural analysis showed that Dy{sub 4}Mn{sub 4}Sn{sub 7} compound is disordered. > Isostructural R{sub 4}Mn{sub 4}Sn{sub 7} compounds were also found with Gd, Tb, Ho, Er, Tm(confirmed), Yb, and Lu. - Abstract: The phase equilibria in the Y-Mn-Sn and Dy-Mn-Sn ternary systems were studied at 770 K by means of X-ray and metallographic analyses in the whole concentration range. Both Y-Mn-Sn and Dy-Mn-Sn systems are characterized by formation of two ternary compounds RMn{sub 6}Sn{sub 6} (MgFe{sub 6}Ge{sub 6}-type, space group P6/mmm) and R{sub 4}Mn{sub 4}Sn{sub 7} (Zr{sub 4}Co{sub 4}Ge{sub 7}-type, space group I4/mmm). The disorder in Dy{sub 4}Mn{sub 4}Sn{sub 7} compound was found by single crystal method. Compounds with the same type of structure were also found with Gd, Tb, Ho, Er, Tm (confirmed), Yb, and Lu and their lattice parameters were determined.

  1. The high-temperature modification of LuAgSn and high-pressure high-temperature experiments on DyAgSn, HoAgSn, and YbAgSn

    Energy Technology Data Exchange (ETDEWEB)

    Heying, B.; Rodewald, U.C.; Hermes, W.; Schappacher, F.M.; Riecken, J.F.; Poettgen, R. [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Heymann, G.; Huppertz, H. [Muenchen Univ. (Germany). Dept. fuer Chemie und Biochemie; Sebastian, C.P. [Max-Planck-Institut fuer Chemische Physik Fester Stoffe, Dresden (Germany)

    2008-02-15

    The high-temperature modification of LuAgSn was obtained by arc-melting an equiatomic mixture of the elements followed by quenching the melt on a water-cooled copper crucible. HT-LuAgSn crystallizes with the NdPtSb-type structure, space group P6{sub 3}mc: a = 463.5(1), c = 723.2(1) pm, wR2 = 0.0270, 151 F{sup 2}, and 11 variables. The silver and tin atoms build up two-dimensional, puckered [Ag{sub 3}Sn{sub 3}] networks (276 pm Ag-Sn) that are charge-balanced and separated by the lutetium atoms. The Ag-Sn distances between the [Ag{sub 3}Sn{sub 3}] layers of 294 pm are much longer. Single crystals of isotypic DyAgSn (a = 468.3(1), c = 734.4(1) pm, wR2 = 0.0343, 411 F{sup 2}, and 11 variables) and HoAgSn (a = 467.2(1), c = 731.7(2) pm, wR2 = 0.0318, 330 F{sup 2}, and 11 variables) were obtained from arc-melted samples. Under high-pressure (up to 12.2 GPa) and high-temperature (up to 1470 K) conditions, no transitions to a ZrNiAl-related phase have been observed for DyAgSn, HoAgSn, and YbAgSn. HT-TmAgSn shows Curie-Weiss paramagnetism with {mu}{sub eff} = 7.53(1) {mu}{sub B}/Tm atom and {theta}P = -15.0(5) K. No magnetic ordering was evident down to 3 K. HT-LuAgSn is a Pauli paramagnet. Room-temperature {sup 119}Sn Moessbauer spectra of HT-TmAgSn and HT-LuAgSn show singlet resonances with isomer shifts of 1.78(1) and 1.72(1) mm/s, respectively. (orig.)

  2. Temperature measurements inside an Er{sup 3+}-Yb{sup 3+} co-doped fluoride crystal heated by a NIR laser diode and probed by red-to-green upconversion

    Energy Technology Data Exchange (ETDEWEB)

    Sayoud, A. [ECATHERM, GRESPI, UFR Sciences, Moulin de la Housse, B.P. 1039, 51687 Reims Cedex 2 (France); Laboratoire de Physique des Lasers, de Spectroscopie Optique et d' Optoelectronique, Departement de Physique, Universite d' Annaba, BP 12, 23000 Annaba (Algeria); Jouart, J.P., E-mail: jean-pierre.jouart@univ-reims.fr [ECATHERM, GRESPI, UFR Sciences, Moulin de la Housse, B.P. 1039, 51687 Reims Cedex 2 (France); Trannoy, N., E-mail: nathalie.trannoy@univ-reims.fr [ECATHERM, GRESPI, UFR Sciences, Moulin de la Housse, B.P. 1039, 51687 Reims Cedex 2 (France); Diaf, M. [Laboratoire de Physique des Lasers, de Spectroscopie Optique et d' Optoelectronique, Departement de Physique, Universite d' Annaba, BP 12, 23000 Annaba (Algeria); Duvaut, T. [ECATHERM, GRESPI, UFR Sciences, Moulin de la Housse, B.P. 1039, 51687 Reims Cedex 2 (France)

    2012-03-15

    The temperature of a transparent Cd{sub 0.7}Sr{sub 0.3}F{sub 2}: Er{sup 3+}(4%)-Yb{sup 3+}(6%) crystalline plate 0.3 mm thick heated by a near-infrared (974 nm) laser diode and probed by a red (652 nm) laser was accurately evaluated as a function of the infrared power absorbed by the Yb{sup 3+} ions. The green emission generated by the Er{sup 3+} ions directly excited by the red laser consists of three major lines (coming from three individual Stark levels in thermal equilibrium) whose intensities were measured according to the absorbed infrared power and the distance between the heated and probed volumes, to evaluate the heating induced by the excitation of Yb{sup 3+} and Er{sup 3+} ions at 974 nm by applying the Boltzmann's equation linking the populations of emitting levels to the temperature. In the case where the Yb{sup 3+} ions excited by the laser diode are situated at a distance of about 0.5 mm from the edge of the crystal and for an absorbed infrared power of 100 mw, the crystal's edge temperature is reaching 80 Degree-Sign C after 20 s of continuous excitation at 974 nm. - Highlights: Black-Right-Pointing-Pointer Photoluminescence (PL) experiments use two excitation wavelengths. Black-Right-Pointing-Pointer One of these wavelengths generates heat. Black-Right-Pointing-Pointer PL intensity variations due to temperature changes were observed. Black-Right-Pointing-Pointer The crystal's temperature was estimated from PL intensity measurements.

  3. Broadband and High Efficient 1530 nm Emission from Oxyfluoride Glass Ceramics Codoped with Er3+ and Yb3+ Ions

    Institute of Scientific and Technical Information of China (English)

    LIU Bao-Rong; ZHAO Li-Juan; SUN Jian; YU Hua; SONG Jie; XU Jing-Jun

    2007-01-01

    The emission at 1530 nm and its applications in optical communications are discussed. The efficient width of the emission band △eff, which is up to 91 nm, is larger as compared with silica-based glass, bismuth glass and ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) glass doped by Er3+ ions. Under the excitation of 785 nm laser, the emission integral intensity of 1530 nm increases about five times in the glass ceramics higher than that in the glass. This is explained by the quantum cutting process by two-photon emission with phonon assistance. The results indicate that the glass ceramics are a promising candidate for developing broadband optical amplifiers in wavelength-division multiplexed systems.

  4. Broadband and High Efficient 1530 nm Emission from Oxyfluoride Glass Ceramics Codoped with Er3+ and Yb3+ Ions

    Science.gov (United States)

    Liu, Bao-Rong; Zhao, Li-Juan; Sun, Jian; Yu, Hua; Song, Jie; Xu, Jing-Jun

    2007-02-01

    The emission at 1530 nm and its applications in optical communications are discussed. The efficient width of the emission band Δeff, which is up to 91 nm, is larger as compared with silica-based glass, bismuth glass and ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) glass doped by Er3+ ions. Under the excitation of 785 nm laser, the emission integral intensity of 1530 nm increases about five times in the glass ceramics higher than that in the glass. This is explained by the quantum cutting process by two-photon emission with phonon assistance. The results indicate that the glass ceramics are a promising candidate for developing broadband optical amplifiers in wavelength-division multiplexed systems.

  5. Enhancement of the 1.53 μm fluorescence and energy transfer in Er{sup 3+}/Yb{sup 3+}/Ce{sup 3+} tri-doped WO{sub 3} modified tellurite-based glass

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Dandan, E-mail: YDD.1986@163.com [College of Information Science and Engineering, Ningbo University, Zhejiang 315211 (China); Peng, Shengxi; Qi, Yawei; Zheng, Shichao; Zhou, Yaxun [College of Information Science and Engineering, Ningbo University, Zhejiang 315211 (China); Wang, Xunsi [Laboratory of Infrared Materials and Devices, The Advanced Technology Research Institute, Ningbo University, Zhejiang 315211 (China)

    2013-12-25

    Highlights: •Er{sup 3+}/Yb{sup 3+}/Ce{sup 3+} tri-doped tellurite glasses containing WO{sub 3} were prepared. •The structure behavior and 1.53 μm band luminescence properties were investigated. •Introduction of WO{sub 3} improves 1.53 μm fluorescence due to enhanced energy transfer. •The ET mechanisms were investigated via calculating micro-parameters. -- Abstract: For the first time, the WO{sub 3} oxide with relatively high phonon energy was introduced into the Er{sup 3+}/Yb{sup 3+}/Ce{sup 3+} tri-doped tellurite-based glasses with composition of TeO{sub 2}-Bi{sub 2}O{sub 3}-TiO{sub 2} to improve the 1.53 μm band fluorescence emission. The X-ray diffraction (XRD) curves, Raman spectra, absorption spectra and 1.53 μm band fluorescence spectra were measured, along with the Judd–Ofelt intensity parameters, stimulated emission and absorption cross-sections, and radiative quantum efficiencies were calculated to evaluate the effects of WO{sub 3} amount on the glass structure and spectroscopic properties especially the 1.53 μm band fluorescence. It is shown that the introduction of an appropriate amount of WO{sub 3} oxide can further improve the 1.53 μm band fluorescence intensity through an enhanced phonon-assisted energy transfer between Er{sup 3+}/Ce{sup 3+} ions and the energy transfer mechanisms between Er{sup 3+}/Yb{sup 3+} (Er{sup 3+}/Ce{sup 3+}) ions are investigated quantitatively in detail by calculating energy transfer microparameters and phonon contribution ratios. The results indicate that the prepared Er{sup 3+}/Yb{sup 3+}/Ce{sup 3+} tri-doped tellurite glass with an appropriate amount of WO{sub 3} oxide is a potential gain medium applied for the 1.53 μm band broad and high-gain EDFA.

  6. 表面活性剂对Y1.2F3∶Yb0.183+/Er0.013+晶体形貌与荧光性能的影响%Influence of Surfactant on Morphology and Upconversion Fluorescent Properties of Y1.2F3∶Yb0.183+/Er0.013+ Crystals

    Institute of Scientific and Technical Information of China (English)

    张艺; 何晓燕; 李紫薇

    2015-01-01

    用溶剂热方法,在乙醇和乙二醇的混合溶剂中,150℃反应24h,成功合成了Y1.2F3∶Yb0.183+/Er0.013+晶体(JCPDS#74-0911).且不同表面活性剂(CTAB)添加量制备了不同形貌和尺寸的YF3晶体.用SEM、IR对产物的形貌和官能团进行了表征.室温下以980 nm为激发光源,合成的晶体有强的上传换发光,发射峰的位置为550 nm、660 nm、835 nm,对应着Er3+离子的4S3/2→4l15/2、4F9/2→4I15/2、4S3/2→4I13/2能级跃迁.实验得出,CTAB的加入及加入量均对YF3晶体形貌、尺寸和荧光性质产生影响,并对上转换发光机理进行了讨论.

  7. Fabrication and upconversion luminescence of Er{sup 3+}/Yb{sup 3+} codoped TeO{sub 2}-WO{sub 3}-Na{sub 2}O-Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3} glass fibers

    Energy Technology Data Exchange (ETDEWEB)

    Narro-Garcia, R., E-mail: rnarro@ipn.mx [Instituto de Fisica GlebWataghin, Universidade Estadual de Campinas-UNICAMP, Campinas, SP 13083-970 (Brazil); Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada Unidad Altamira, km 14.5 Carretera Tampico-Puerto Industrial Altamira 89600, Tamaulipas (Mexico); Chillcce, E.F.; Barbosa, L.C. [Instituto de Fisica GlebWataghin, Universidade Estadual de Campinas-UNICAMP, Campinas, SP 13083-970 (Brazil); Posada, E. de; Arronte, M.; Rodriguez, E. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada Unidad Altamira, km 14.5 Carretera Tampico-Puerto Industrial Altamira 89600, Tamaulipas (Mexico)

    2013-02-15

    The tellurite fibers based on glasses with the composition TeO{sub 2}-WO{sub 3}-Nb{sub 2}O{sub 5}-Na{sub 2}O-Al{sub 2}O{sub 3}-Er{sub 2}O{sub 3}-Yb{sub 2}O{sub 3} were fabricated by the rod-in-tube technique using a Heathway drawing tower. The upconversion luminescence of Er{sup 3+}/Yb{sup 3+} codoped tellurite glass fibers under 980 nm excitation were investigated. The Er{sup 3+}/Yb{sup 3+}co-doped tellurite fibers show an efficient up-conversion process in comparison with the Er{sup 3+}-doped tellurite fibers. The pump power dependent intensities were discussed, which showed that two photons are involved in the upconversion process. - Highlights: Black-Right-Pointing-Pointer We fabricate Er{sup 3+}/Yb{sup 3+} codoped TeO{sub 2}-WO{sub 3}-Na{sub 2}O-Nb{sub 2}O{sub 5}-Al{sup 2}O{sub 3} glass fibers. Black-Right-Pointing-Pointer We evaluate the upconversion luminescence of these tellurite fibers. Black-Right-Pointing-Pointer The pump power dependent intensities were discussed. Black-Right-Pointing-Pointer The Er{sup 3+}/Yb{sup 3+}+co-doped tellurite fibers show an efficient upconversion process. Black-Right-Pointing-Pointer We show that two photons are involved in the upconversion process.

  8. New Sr{sub 1−x−z}R{sub x}(NH{sub 4}){sub z}F{sub 2+x−z} (R = Yb, Er) solid solution as precursor for high efficiency up-conversion luminophor and optical ceramics on the base of strontium fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Rozhnova, Yu. A. [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation); A.M. Prokhorov General Physics Institute, RAS, Moscow (Russian Federation); Kuznetsov, S.V. [A.M. Prokhorov General Physics Institute, RAS, Moscow (Russian Federation); Luginina, A.A. [All-Russian Institute for Scientific and Technical Information (VINITI), Moscow (Russian Federation); Voronov, V.V.; Ryabova, A.V.; Pominova, D.V.; Ermakov, R.P. [A.M. Prokhorov General Physics Institute, RAS, Moscow (Russian Federation); Usachev, V.A.; Kononenko, N.E. [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation); Baranchikov, A.E.; Ivanov, V.K. [N.S. Kurnakov Institute of General and Inorganic Chemistry, RAS, Moscow (Russian Federation); Fedorov, P.P., E-mail: ppfedorov@yandex.ru [A.M. Prokhorov General Physics Institute, RAS, Moscow (Russian Federation)

    2016-04-01

    In this paper, we describe the use of self-fluorinating conditions for the thermal treatment of Sr{sub 1−x−y−z}Yb{sub x}Er{sub y}(NH{sub 4}){sub z}F{sub 2+x+y−z} precursor for the preparation of high-efficiency SrF{sub 2}:Yb:Er up-converter powders. We report actual SrF{sub 2}:Yb:Er compositions with up-conversion efficiencies exceeding 4% (pumping power 1 W/cm{sup 2} at 974 nm wavelength) and describe the synthesis of ceramics with higher than 80% transmittance at 0.42–7.0 μm. The latter ceramics can be used as a potential IR radiation visualizer. For the first time, we present an analysis of correlation between up-conversion luminescence energy yield and specimen composition for SrF{sub 2}:Yb:Er nanopowders. Taking into account the observed erbium ion up-conversion luminescence in the red part of the visible spectrum, we recommend certain SrF{sub 2}:Yb:Er compositions for practical application in photodynamic cancer therapy. - Highlights: • SrF{sub 2}:Yb/Er luminophor nanopowders were precipitated from aqueous solutions. • Precipitation of Sr{sub 1−x−y−z}Yb{sub x}Er{sub y}(NH{sub 4}){sub z}F{sub 2+x+y−z} solid solution has been proved. • Up-conversion luminescence energy yield luminophors of more than 4% were obtained. • Optical ceramics with 80% transmittance in 0.42–7.0 μm range was synthesized.

  9. Controlled synthesis and temperature-dependent spectra of NaYF4:Yb3+, Re3+@NaYF4@SiO2 (RE = Er, Tm) core-shell-shell nanophosphors

    Science.gov (United States)

    Bu, Y. Y.; Yan, X. H.

    2017-02-01

    The NaYF4 Yb3+, Re3+@NaYF4@SiO2 (RE = Er, Tm) core-shell-shell nanophosphors were synthesized by thermal decomposition of lanthanide trifluoroacetate precursors and subsequent hydrolysis coating process. Structures of resulting nanophosphors are studied by the X-ray diffraction and high-resolution transmission electron microscopy. Temperature-dependent photoluminescence spectra, thermal quenching ratios, fluorescence intensity ratios, and temperature sensitivity of resulting nanoparticles are studied in the temperature range from 298 to 623 K. The results suggest that the NaYF4:Yb3+, Er3+@NaYF4@SiO2 is a suitable candidate for making a low temperature sensor up to 450 K with a maximum sensitivity of 24 × 10-4 K-1, and the NaYF4:Yb3+, Tm3+@NaYF4@SiO2 is an excellent candidate for temperature sensors at high temperature. This work presents a new method to use the fluoride nanocrystals as the optical thermometry at high temperature.

  10. Up-conversion emission tuning in triply-doped Yb3+/Tm3+/Er3+ novel fluoro-phosphate glass and glass-ceramics

    Science.gov (United States)

    Ledemi, Yannick; Trudel, Andrée.-Anne; Rivera, Victor A. G.; Messaddeq, Younes

    2014-03-01

    New Yb3+, Er3+ and Tm3+ triply doped fluoro-phosphate glasses belonging to the system NaPO3-YF3-BaF2-CaF2 have been prepared by the classical melt-casting technique. Glasses containing up to 10 wt.% of rare-earth ions fluorides have been obtained and characterized by using differential scanning calorimetry (DSC), UV-visible-near-infrared spectroscopy and up-conversion emission spectroscopy under excitation with a 975 nm laser diode. Transparent and optically homogeneous glass-ceramics have been reproducibly obtained by appropriate heat treatment in view to manage the red, green and blue emissions upon 975 nm laser excitation. According to the applied thermal heat-treatment, a large enhancement of intensity of the up-conversion emission - from 10 to 160 times higher - has been achieved in the glassceramics compared to that of glasses, suggesting incorporation of the rare-earth ions into the crystalline phase. Furthermore, a large range of color rendering has been observed in these materials by controlling the laser excitation power and material crystallization rate. Time-resolved luminescence experiments as well as X-ray diffractometry and scanning electron microscopy techniques have been employed in order to understand and correlate the multicolor emission changes to the crystallization behavior of this material. A progressive phase transformation of the fluorite-type CaF2-based nanocrystals initially generated was observed along with increasing heat-treatment time, thus modifying the rare earth ions spectroscopic features.

  11. Ion conductivity in cubically-stabilized fluorite-like structured Er5CeMoO12.5 and Yb5MMoO12.5 (M = Ce, Zr) solid solutions

    Science.gov (United States)

    Schildhammer, Daniel; Fuhrmann, Gerda; Petschnig, Lucas; Kogler, Michaela; Penner, Simon; Weinberger, Nikolaus; Schottenberger, Herwig; Huppertz, Hubert

    2016-12-01

    For the first time, the usually rhombohedral R 3 bar (no. 148) defect fluorite structured rare earth molybdenum oxides RE6MoO12 (RE = Er, Yb) could be stabilized in the cubic defect fluorite structure Fm 3 bar m (no. 225) through partial substitution of Er3+ and Yb3+ by M4+ cations with M4+ = Ce for Er6MoO12 and M4+ = Ce, Zr for Yb6MoO12. The solution combustion (SC) method and the classical solid state reaction are the synthetic approaches that were used (ambient atmosphere and temperatures of 1250 °C). The obtained oxide powders were characterized by energy dispersive X-ray (EDX) analysis, powder X-ray diffraction (PXRD), IR, and UV-Vis spectroscopy. The PXRD-data were used for Rietveld refinements. Electrochemical impedance spectroscopy (EIS) was conducted to identify oxygen vacancies in the cubic structure type, revealing oxygen ion conductivity starting at 500 °C. Additionally, the influence on ion conductivity by the cation substitutions are discussed. Calculation of the contributing activation energies for the bulk (best value for Yb5CeMoO12.5 is 119.8 kJmol-1), and the grain boundary (e.g. Er5CeMoO12.5: 152.1 kJmol-1) analyzed by means of the Arrhenius plot, shows similarities to the conventional stabilization of zirconia with yttrium (8-YSZ) (110 kJ mol-1 and 110-163 kJmol-1 respectively). The best-calculated conductivity values σ = 1.03 × 10-4 Scm-1 obtained for Er5CeMoO12.5 at 1000 °C are comparable to the values published for 8-YSZ with σ = 3.94 × 10-5 Scm-1 at similar temperatures. These promising preliminary results underline the potential of the title compounds for application in solid oxide fuel cells (SOFCs).

  12. Polarized spectroscopic properties of Er{sup 3+}:Gd{sub 2}SiO{sub 5} crystal and evaluation of Er{sup 3+}:Yb{sup 3+}:Gd{sub 2}SiO{sub 5} crystal as a 1.55 μm laser medium

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H. [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Huang, J.H.; Gong, X.H.; Chen, Y.J.; Lin, Y.F.; Luo, Z.D. [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Huang, Y.D., E-mail: huyd@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

    2016-10-01

    An Er{sup 3+}-doped Gd{sub 2}SiO{sub 5} single crystal with high optical quality has been grown by the Czochralski method. Polarized absorption and fluorescence spectra and fluorescence lifetime of the crystal were measured at room temperature. Intensity parameters, spontaneous emission probabilities, fluorescence branching ratios, and radiative lifetimes were estimated on the basis of the Judd–Ofelt theory. Besides, potentiality of 1.55 μm laser emission in an Er{sup 3+}–Yb{sup 3+} co-doped Gd{sub 2}SiO{sub 5} crystal was evaluated.

  13. Bulk glass ceramics containing Yb{sup 3+}/Er{sup 3+}: β-NaGdF{sub 4} nanocrystals: Phase-separation-controlled crystallization, optical spectroscopy and upconverted temperature sensing behavior

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Daqin, E-mail: dqchen@fjirsm.ac.cn [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Wan, Zhongyi; Zhou, Yan [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Huang, Ping, E-mail: phuang@fjirsm.ac.cn [Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Zhong, Jiasong; Ding, Mingye [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Xiang, Weidong; Liang, Xiaojuan [College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035 (China); Ji, Zhenguo, E-mail: jizg@hdu.edu.cn [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)

    2015-07-25

    Highlights: • Hexagonal NaGdF{sub 4} nanocrystals embedded bulk glass ceramics were fabricated. • The incorporation of Ln{sup 3+} dopants into the β-NaGdF{sub 4} lattice was demonstrated. • Upconversion luminescence was highly intensified after glass crystallization. • Such glass ceramics had possible application in the optical temperature sensors. - Abstract: Lanthanide doped hexagonal β-NaGdF{sub 4} nanocrystals embedded transparent bulk glass ceramics were successfully fabricated via a phase-separation-controlled crystallization route. Elemental mapping in the scanning transmission electron microscope and optical spectroscopy analysis demonstrated the partition of the active centers into the β-NaGdF{sub 4} crystalline lattice. As a result, upconversion luminescence of the glass ceramic co-doped with Yb{sup 3+} and Er{sup 3+} is about 60 times as high as that of the precursor glass, attributing to the modification of Yb{sup 3+}/Er{sup 3+} surrounding from phase-separated amorphous nanoparticle to β-NaGdF{sub 4} crystalline lattice with low phonon energy and high crystallinity after crystallization. Furthermore, the temperature-dependent green upconversion emissions assigned to {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2} (520 nm) and {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} (540 nm) transitions were investigated, and the corresponding fluorescence intensity ratio of these two thermally coupled emitting-states greatly enhanced with increase of temperature. Using such fabricated glass ceramic as an optical thermometric medium, the maximum sensitivity reached as high as 0.0037 K{sup −1} at 580 K. It is expected that the investigated Er{sup 3+}/Yb{sup 3+} codoped glass ceramic might be a very promising candidate for accurate optical temperature sensors.

  14. Crystal Structure and Upconversion Emission of Yb 3+/Er3+-Co-Doped NaYF4 Nanocrystals%Yb3+/Er3+共掺NaYF4的晶体结构和上转换发光性能的研究

    Institute of Scientific and Technical Information of China (English)

    姚丽丽; 罗莉; 董国帅; 王银海

    2013-01-01

    以乙二胺四乙酸(EDTA)为螯合剂,用一种改进的共沉淀法制备了 Yb3+/Er3+共掺的立方相NaYF4和Yb3+/Er3+/Gd3+三掺的六角相NaYF4纳米晶。用透射电子显微镜、X射线衍射、荧光光谱等测量手段对样品的形貌、晶相和发光性能进行了表征。结果表明,通过掺杂Gd3+,实现了NaYF4基质从立方相到六角相的相变。虽然据报道六角相的NaYF4比立方相的NaYF4上转换效率高,但是相变对上转换荧光光谱的影响还不清楚。本文着重研究了相变对晶格场能级分裂、发光强度和发光颜色的调控作用,提出了荧光增强和发光颜色可调的机理。用10 mW ,980 nm二极管激光激发,在立方相和六角相样品中均观察到肉眼可见的上转换荧光发射,分别是525/550 nm附近2 H11/2/4 S3/2→4 I15/2跃迁引起的绿光发射和657 nm附近4 F9/2→4 I15/2跃迁引起的红光发射。与立方相样品相比,六角相样品荧光发射谱线变窄,荧光强度增强了一个量级,出现了2 H9/2→4 I13/2跃迁引起的新发射峰,红绿比由2∶1增大到3∶1,这是因为六角相基质的晶格场对称性降低,于是增强了上转换荧光强度,同时六角相的晶胞体积变小,提高了掺杂离子周围的晶格场强度,导致发射谱线变锐,表明相变可以调节晶格场能级分裂,发光强度和发光颜色。%Yb3+ /Er3+-co-doped cubic NaYF4 and Yb3+ /Er3+ /Gd3+-tri-doped hexagonal NaYF4 nanocrystals were synthesized by a modified coprecipitation method with ethylenediamine tetraacetic acid (EDTA) as chelating agent .The samples’ morphology , crystal phase and upconversion emission were measured with transmission electron microscope (TEM ) ,X-ray diffraction pat-terns (XRD) and upconversion luminescence spectrum .TEM and XRD results showed that the phase transition from cubic to hexagonal was promoted through Gd3+ doping .It has been reported that the

  15. Croissance de fibres à gradient de concentration et analyse des processus dynamiques de transitions laser résonnantesdans Y203 dopé Er^{3+}, Yb^{3+} et Ho^{3+}

    Science.gov (United States)

    Laversenne, L.; Goutaudier, C.; Guyot, Y.; Cohen-Adad, M. Th.; Boulon, G.

    2002-06-01

    La croissance et l'exploitation de fibres à gradient de concentration de Y203 dopé par des ions terres rares permet d'étudier les processus dynamiques de transitions laser résonnantes des ions Yb^{3+}, Er^{3+} et Ho^{3+}. Plus particulièrement nous mettons en évidence et analysons les transferts d'énergie radiatifs (self trapping) responsables de l'allongement de la durée de vie expérimentale.

  16. Metathesis synthesis, characterization, spectral and photoactivity studies of Ln2/3MoO4 (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er and Y)

    Institute of Scientific and Technical Information of China (English)

    Radha Velchuri; Suresh Palla; G. Ravi; Naveen Kumar Veldurthi; J.R. Reddy; M. Vithal

    2015-01-01

    Rare earth ortho-oxomolybdates of composition Ln2/3MoO4 (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er and Y) were prepared by metathesis reaction. All these materials were characterized by powder X-ray diffraction, Fourier transform-infrared spectroscopy (FT-IR) and UV-Vis diffuse reflectance spectra. The Rietveld analysis of all the samples was carried out to obtain the unit cell pa-rameters and reliability factors. All the materials were crystallized in tetragonal lattice withI41/a space group. The infrared spectra of all the samples were characterized by bands due to MoO42– units. The bandgap energies of all the samples were obtained from UV-Vis DRS spectra. The luminescence spectra of Ln2/3MoO4 (Ln=Pr, Eu and Dy) showed characteristic transitions of the rare earth ions. The visible light photocatalytic activity of all the samples was studied against degradation of methylene blue.

  17. Numerical Simulation of 980 nm-LD-Pumped Yb3+-Er3+-Tm3+-Codoped Fiber Amplifier for 1500 nm and 1600 nm Bands

    Directory of Open Access Journals (Sweden)

    Chun Jiang

    2009-01-01

    Full Text Available The theoretical model of Yb3+-Er3+-Tm3+-codoped fiber amplifier pumped by 980 nm laser is proposed, and the rate and power propagation equations are numerically solved to analyze the dependences of the gains at 1500 nm and 1600 nm bands on the activator concentrations, fiber length, pump power, and signal wavelength. The numerical results show that our model is in good agreement with experimental result, and with pump power of 200 mW and fiber length varying from 0.15 to 1.5 m, the gains at the two bands may reach 10.0–20.0 dB when the codoping concentrations of Yb3+, Er3+, and Tm3+ are in the ranges 1.0–3.0×1025, 1.0–3.0×1024, and 1.0–3.0×1024 ions/m3, respectively. The fiber parameters may be optimized to flatten the gain spectra.

  18. Y2O3:Yb,Er@mSiO2-Cu(x)S double-shelled hollow spheres for enhanced chemo-/photothermal anti-cancer therapy and dual-modal imaging.

    Science.gov (United States)

    Yang, Dan; Yang, Guixin; Wang, Xingmei; Lv, Ruichan; Gai, Shili; He, Fei; Gulzar, Arif; Yang, Piaoping

    2015-07-28

    Multifunctional composites have gained significant interest due to their unique properties which show potential in biological imaging and therapeutics. However, the design of an efficient combination of multiple diagnostic and therapeutic modes is still a challenge. In this contribution, Y2O3:Yb,Er@mSiO2 double-shelled hollow spheres (DSHSs) with up-conversion fluorescence have been successfully prepared through a facile integrated sacrifice template method, followed by a calcination process. It is found that the double-shelled structure with large specific surface area and uniform shape is composed of an inner shell of luminescent Y2O3:Yb,Er and an outer mesoporous silica shell. Ultra small Cu(x)S nanoparticles (about 2.5 nm) served as photothermal agents, and a chemotherapeutic agent (doxorubicin, DOX) was then attached onto the surface of mesoporous silica, forming a DOX-DSHS-Cu(x)S composite. The composite exhibits high anti-cancer efficacy due to the synergistic photothermal therapy (PTT) induced by the attached Cu(x)S nanoparticles and the enhanced chemotherapy promoted by the heat from the Cu(x)S-based PTT when irradiated by 980 nm near-infrared (NIR) light. Moreover, the composite shows excellent in vitro and in vivo X-ray computed tomography (CT) and up-conversion fluorescence (UCL) imaging properties owing to the doped rare earth ions, thus making it possible to achieve the target of imaging-guided synergistic therapy.

  19. Role of Lanthanide-Ligand bonding in the magnetization relaxation of mononuclear single-ion magnets: A case study on Pyrazole and Carbene ligated LnIII(Ln=Tb, Dy, Ho, Er) complexes

    Indian Academy of Sciences (India)

    TULIKA GUPTA; GUNASEKARAN VELMURUGAN; THAYALAN RAJESHKUMAR; GOPALAN RAJARAMAN

    2016-10-01

    Ab initio CASSCF+RASSI-SO+SINGLE_ANISO and DFT based NBO and QTAIM investigations were carried out on a series of trigonal prismatic M(BcMe)₃ (M = Tb(1), Dy(2), Ho(3), Er(4), [BcMe]⁻ = dihydrobis (methylimidazolyl) borate) and M(BpMe)₃ (M = Tb(1a), Dy(2a), Ho(3a), Er(4a) [BpMe]⁻ = dihydrobis (methypyrazolyl) borate) complexes to ascertain the anisotropic variations of these two ligand field environments and the influence of Lanthanide-ligand bonding on the magnetic anisotropy. Among all the complexes studied, only 1 and 2 show large Ucal (computed energy barrier for magnetization reorientation) values of 256.4 and 268.5 cm⁻¹, respectively and this is in accordance with experiment. Experimentally only frequency dependent χ” tails are observed for complex 1a and our calculation predicts a large Ucalof 229.4 cm⁻¹ for this molecule. Besides these, none of the complexes (3, 4, 2a, 3a and 4a) computed to possess large energy barrier and this is affirmed by the experiments. These observed differences in the magnetic properties are correlated to the Ln-Ligand bonding. Our calculations transpire comparatively improved Single-Ion Magnet (SIM) behaviour for carbene analogues due to the more axially compressed trigonal prismatic ligand environment. Furthermore, our detailed Mulliken charge, spin density, NBO and Wiberg bond analysis implied stronger Ln...H–BH agostic interaction for pyrazole analogues. Further, QTAIM analysis reveals the physical nature of coordination, covalent, and fine details of the agostic interactions in all the eight complexes studied. Quite interestingly, for the first time, using the Laplacian density, we are able to quantify the prolate and oblate nature of the electron clouds in lanthanides and this is expected to have a far reaching outcome beyond the examples studied.

  20. Monodisperse and hollow structured Y{sub 2}O{sub 3}:Ln{sup 3+} (Ln = Eu, Dy, Er, Tm) nanospheres: A facile synthesis and multicolor-tunable luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ruiqing; Zi, Wenwen; Li, Linlin; Liu, Lu; Zhang, Junjun [College of Chemistry, Jilin University, Changchun 130026 (China); Zou, Lianchun, E-mail: zoulianchun@126.com [Teaching Center of Basic Courses, Jilin University, Changchun 130062 (China); Gan, Shucai, E-mail: gansc@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130026 (China)

    2014-12-25

    Highlights: • We reported a simple route to synthesize the Y{sub 2}O{sub 3} HNSs. • A possible formation mechanism of the Y{sub 2}O{sub 3} HNSs was proposed. • The Ln-doped Y{sub 2}O{sub 3} HNSs exhibit characteristic emission with different colors. • White-light-emitting phosphor Y{sub 2}O{sub 3}:Tm{sup 3+}, Dy{sup 3+} was also successfully synthesized. - Abstract: A novel, fast and simple method was developed to synthesize the undoped and lanthanide-doped yttrium oxide hollow nanospheres (Y{sub 2}O{sub 3}⋅HNSs) with multicolored downconversion emission under mild conditions by employing poly (acrylic acid sodium salt) microspheres (PAAS MSs) as active templates followed by a subsequent calcination process. The structure, morphology, formation process, and fluorescent properties are well investigated using various techniques. The results show that the samples can be well indexed to the pure cubic phase of Y{sub 2}O{sub 3}. The possible formation mechanism of the PAAS MSs, PAA-Y precursor, and Y{sub 2}O{sub 3} HNSs are proposed and discussed in detail. Upon ultraviolet excitation, the obtained Y{sub 2}O{sub 3}:Ln{sup 3+} (Ln = Eu, Dy, Er, Tm) HNSs exhibit strong red, yellow–green, blue, yellow emission, respectively. Moreover, a novel single-phased and near-UV-pumped white-light-emitting phosphor Y{sub 2}O{sub 3}:Tm{sup 3+}, Dy{sup 3+} was also successfully fabricated through optimizing the molar ratio among Tm{sup 3+} and Dy{sup 3+} in the Y{sub 2}O{sub 3} host. This material may find potential applications in field-emission display devices and white ultraviolet light-emitting diodes (UV LEDs). Furthermore, this synthesis route may be of great significance in the preparation of other hollow spherical materials.

  1. ПОЛУЧЕНИЕ ПОРОШКОВ ТВЕРДЫХ РАСТВОРОВ SR(ND, GD)S4, SR(DY, ER)S4

    OpenAIRE

    Елышев, Андрей; Андреев, Олег

    2011-01-01

    Установлена последовательность фазовых превращений, происходящих при сульфидировании шихты SrO, Nd2O3, Gd2O3; SrO, Dy2O3, Er2O3, с образованием порошков твердых растворов Sr(NdGd)S4, с кубической структурой типа Th3P4, Sr(DyEr)S4 ромбической структурой типа CaFe2O4.

  2. Structural and light up-conversion luminescence properties of Er{sup 3+}-Yb{sup 3+}-W{sup 6+} substituted Bi{sub 4}Ti{sub 3}O{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Bokolia, Renuka, E-mail: renuka1274@gmail.com; Chauhan, Lalita; Sreenivas, K. [Department of Physics & Astrophysics, University of Delhi, Delhi-110007 (India); Rai, Vineet K. [Laser & Spectroscopy Laboratory, Department of Applied Physics, Indian School of Mines, Dhanbad 826 004, Jharkhand (India)

    2016-05-23

    The structural and light up-conversion (UC) luminescence properties of W{sup 6+} substituted Bi{sub 3.79}Er{sub 0.03}Yb{sub 0.18}Ti{sub 3-x}W{sub x}O{sub 12} (0 ≤ x ≤ 0.10) ceramics prepared by solid state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of single phase material with orthorhombic structure. A decrease in the lattice parameters and unit cell volume is observed with increasing W content. Strong UC luminescence at 527, 548 and 662 nm is seen under an excitation of 980 nm for an optimum W content (x = 0.06) and is attributed to the transitions {sup 2}H{sub 11/2} →{sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} →{sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} →{sup 4}I{sub 15/2} respectively. The improved UC luminescence is ascribed to the reduced defects such as oxygen vacancies and change in the crystal field around Er{sup 3+} ions due to B-site (Ti{sup 4+}) substitution with W{sup 6+} ions. Enhanced UC emission is observed for an optimum content of w{sup 6+} in the prepared composition Bi{sub 3.79}Er{sub 0.03}Yb{sub 0.18}Ti{sub 3-x}W{sub x}O{sub 12} for x = 0.06.

  3. Thermal decomposition of heavy rare-earth butanoates, Ln(C3H7CO2)3 (Ln = Er, Tm, Yb and Lu) in argon

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Yue, Zhao; Tang, Xiao

    2016-01-01

    The thermal behaviour of Ln(C3H7CO2)3 (Ln = Er, Tm, Yb or Lu) was studied in argon from room temperature by means of thermogravimetry and differential thermal analysis up to 1400 °C, by infrared spectroscopy, hot-stage optical microscopy and X-ray diffraction. Melting prior to decomposition...... was observed in all four compounds, but its course depends on the rare-earth element. Decomposition to sesquioxides proceeds via the formation of dioxymonocarbonates (Ln2O2CO3) and release of 4-heptanone (C3H7COC3H7) as well as carbon dioxide (CO2) without evidence for an intermediate oxobutanoate stage...

  4. Infrared Study of Er3+/Yb3+ Co-Doped GeO2-PbO-Bi2O3 Glass

    Directory of Open Access Journals (Sweden)

    Mohamed K. Halimah

    2012-07-01

    Full Text Available Heavy metal oxide glasses, containing bismuth and/or lead in their glass structure are new alternatives for rare eart (RE doped hosts. Hence, the study of the structure of these vitreous systems is of great interest for science and technology. In this research work, GeO2-PbO-Bi2O3 glass host doped with Er3+/Yb3+ ions was synthesized by a conventional melt quenching method. The Fourier transform infrared (FTIR results showed that PbO and Bi2O3 participate with PbO4 tetragonal pyramids and strongly distort BiO6 octahedral units in the glass network, which subsequently act as modifiers in glass structure. These results also confirmed the existence of both four and six coordination of germanium oxide in glass matrix.

  5. Effect of glass network modifier R2O (R=Li, Na and K) on upconversion luminescence in Er3+/Yb3+ co-doped NaYF4 oxyfluoride glass-ceramics

    Institute of Scientific and Technical Information of China (English)

    高源; 胡曰博; 任鹏; 周大成; 邱建备

    2015-01-01

    The effect of glass network modifier R2O (R=Li, Na, K) on upconversion luminescence in Er3+/Yb3+ co-doped NaYF4 oxyfluoride glass-ceramics was investigated. NaYF4 nanocrystals with different sizes were studied under glass network modifier alkali mental oxide. The nanocrystals size in NaYF4 of Li2O modified samples was 11 nm, whereas in the Na2O and K2O modi-fied sample, the crystal size was 25 and 43 nm, respectively. It was found that red, yellow and green upconversions were observed in SAL, SAN, SAK glass ceramics. The reported results would deepen the understanding of size effects on the lanthanide upcon-version in nanocrystals.

  6. White light up-conversion in transparent sol-gel derived glass-ceramics containing Yb{sup 3+}-Er{sup 3+}-Tm{sup 3+} triply-doped YF{sub 3} nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Santana-Alonso, A. [Departamento Fisica Basica, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain); Mendez-Ramos, J. [Departamento Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain); Yanes, A.C., E-mail: ayanesh@ull.es [Departamento Fisica Basica, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain); Castillo, J. del [Departamento Fisica Basica, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain); Rodriguez, V.D. [Departamento Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain)

    2010-11-01

    Transparent glass-ceramics containing YF{sub 3} nanocrystals triply-doped with Yb{sup 3+}-Er{sup 3+}-Tm{sup 3+} ions have been successfully obtained under adequate thermal treatment of precursor sol-gel glasses for the first time to our knowledge. X-ray diffraction and high resolution transmission electron microscopy analysis pointed out the precipitation of YF{sub 3} nanocrystals. Up-conversion luminescence features confirm the effective partition of luminescent ions into precipitated nanocrystals. Corresponding energy transfer up-conversion mechanisms and the dependence of the overall emitting colour have been analyzed as a function of doping ions, with varying concentration. In particular, very bright and efficient up-conversion emission, almost matching the standard equal energy white light illumination point of the standard chromaticity diagram, has been achieved showing up as promising candidate material for potential applications in photonic integrated devices and infrared tuneable phosphors.

  7. Optical properties of nanocrystalline-coated Y{sub 2}O{sub 3}:Er{sup 3+}, Yb{sup 3+} obtained by mechano-chemical and combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Rodriguez, R., E-mail: rosa.martin@unican.e [Dpto. de Fisica Aplicada, Universidad de Cantabria, Santander 39005 (Spain); Valiente, R. [Dpto. de Fisica Aplicada, Universidad de Cantabria, Santander 39005 (Spain); Pesquera, C.; Gonzalez, F.; Blanco, C. [Dpto. de Ingenieria Quimica y Quimica Inorganica, Univ. de Cantabria, Santander 39005 (Spain); Potin, V.; Marco de Lucas, M.C. [Institut Carnot de Bourgogne, UMR 5209 CNRS-Universite de Bourgogne, BP 47 870, F-21078 Dijon Cedex (France)

    2009-09-15

    Y{sub 2}O{sub 3}:Er{sup 3+}, Yb{sup 3+} nanocrystals have been obtained by ball milling and using a combustion synthesis procedure. In both cases the nanocrystals have been successfully coated with SiO{sub 2} following the Stoeber method. The average size of the as-synthesized nanoparticles has been estimated from X-ray diffraction patterns and transmission electron microscopy images. The dependence of the optical properties of these samples on synthesis procedure or dopant concentration has been investigated. Emission, excitation and lifetime measurements have been carried out. Upconversion luminescence has been detected in all samples and an enhancement of the red to green emission ratio has been observed in all samples after infrared compared to visible excitation. The mechanisms responsible for the upconversion phenomena have been discussed.

  8. High efficiency white luminescence in Tm{sup 3+}/Er{sup 3+}/Yb{sup 3+} tri-doped oxyfluoride glass ceramic microsphere pumped by 976 nm laser

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jing; Huang, Yantang, E-mail: huangyantang@fzu.edu.cn; Wu, Tianjiao; Huang, Yu; Zhang, Peijin

    2015-01-15

    In this paper, transparent Tm{sup 3+}/Er{sup 3+}/Yb{sup 3+} tri-doped oxyfluoride glass ceramic samples containing LaF{sub 3} nanocrystals were prepared by a melt quenching method, and were subsequently fabricated into transparent microspheres with handles. A new method to study the luminescent properties of Tm{sup 3+}/Er{sup 3+}/Yb{sup 3+} tri-doped oxyfluoride glass ceramic was proposed, which was using the biconical tapered fiber-microsphere coupled structure. The structure has characteristics of low excitation optical power, easy preparation and convenient testing. We obtained strong white light including the blue (471 nm), green (523 nm and 544 nm) and red (651 nm) emission under the excitation of a 976 nm laser diode (LD) and the relationship of the luminous flux of white light versus pump power simultaneously. In addition, the up-conversion (UC) luminescence mechanism of rare earth (RE) ions and the reason of high luminescence efficiency in our experiment were also explained. The white light obtained by UC of 976 nm laser has more advantages than that by down-conversion of blue light. It may be applied in many fields such as background light, lighting, etc. - Highlights: • A new method to study the luminescent properties of glass materials is proposed. • The white light was obtained by up-conversion of 976 nm laser. • The mechanism of up-conversion luminescence was clearly explained. • The advantages of the white luminescence excited by 976 nm were reported.

  9. Femtosecond-pulse laser-ablation-induced synthesis and improved emission properties of ultrafine Y{sub 2}O{sub 3}:Er{sup 3+}, Yb{sup 3+} nanoparticles with reduced nonradiative relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Changbin, E-mail: zhengchangbin@ciomp.ac.cn; Yang, Guilong; Zhang, Kuo; Wang, Chunrui; Wang, Hualong; Chen, Fei; He, Yang

    2015-11-05

    Nanomaterials with effective visible upconversion emission have received special attention due to the potential application in the fields including biological labeling, imaging, and photodynamic therapy. The main focus of this work is the improvement of the upconversion emission properties, which is enhanced emission intensity and prolonged decay time, by reducing nonradiative relaxation assisted by high energy phonon. Y{sub 2}O{sub 3}:Er{sup 3+}, Yb{sup 3+} nanoparticles (considerably < 50 nm) were directly prepared through femtosecond-pulse laser ablation conducted on the corresponding oxide mixture. It was observed that the number of carbonate and hydroxyl groups remaining in the nanoparticles was decreased. The upconversion and infrared emission properties of the particles were investigated using 976-nm continuous-wave laser radiation, and it was found that the relative red-to-green emission intensity decreased. The samples also exhibited higher integral intensity and reduced power dependence on the excitation intensity, which indicates a more effective upconversion process. The decay time for upconversion emission was lengthened, and for the first time (to the best of our knowledge), infrared emission at 1550 nm was almost suppressed. As a result of the elimination of the carbonate and hydroxyl groups, nonradiative relaxation assisted by high-energy phonons was reduced, thereby increasing the decay time and upconversion emission and decreasing the infrared emission. - Graphical abstract: Reduced nonradiative relaxation leads to higher upconversion emission intensity and decreased relative red-to-green emission intensity. - Highlights: • Y{sub 2}O{sub 3}:Er{sup 3+}, Yb{sup 3+} nanoparticles are prepared by laser ablation on the oxide mixture. • Number of carbonate and hydroxyl groups in the nanoparticles is decreased. • These nanoparticles present improved emission properties. • For the first time, infrared emission at 1550 nm is almost suppressed.

  10. Hydrothermal synthesis of superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er core@shell monodisperse nanoparticles and their subsequent ligand exchange in water

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhenli; Du, Sinan; Luo, Yang; Liao, Zhijian; Zuo, Fang, E-mail: polymerzf@swun.cn; Luo, Jianbin; Liu, Dong

    2016-08-15

    Graphical abstract: An efficient hydrothermal method was used to fabricate the superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2(*)+}-doped NaYF{sub 4}:Yb/Er nanoparticles (NPs) with core@shell structures through a seed-growth procedure. Then using PEG phosphate ligand to displace oleate from the as-synthesized NPs, hydrophilic Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er NPs with good water solubility are obtained. - Highlights: • Homogeneous size distribution of magnetic-upconversion core@shell structured nanoparticles (NPs) were synthesized. • The core@shell nanostructures were obtained by seed-growth method. • The oleic acid coated Fe{sub 3}O{sub 4} NPs were used as seeds and cores. • The magnetic-upconversion NPs emitted red luminescence under a 980 nm laser. • Synthesized magnetic-upconversion NPs were phase transferred using ligand exchange process. - Abstract: We report the use of an efficient hydrothermal method to synthesize superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er nanoparticles (NPs) with core@shell structures via a seed-growth procedure. Oleic acid coated Fe{sub 3}O{sub 4} (OA-Fe{sub 3}O{sub 4}) NPs were initially synthesized using a coprecipitation method. The as-synthesized OA-Fe{sub 3}O{sub 4} NPs were then used as seeds, on which the red upconversion luminescent shell (Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er) was formed. Furthermore, hydrophobic to hydrophilic surface modification of the Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er NPs was achieved via a ligand exchange method where oleic acid was displaced by a PEG phosphate ligand [PEG = poly(ethylene glycol)]. These materials were characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, and vibrating sample magnetometry (VSM). The Fe{sub 3}O{sub 4} cores were uniformly coated with a Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er

  11. Features of magnetic and thermal properties of R(Co{sub 1−x}Fe{sub x}){sub 2} (x≤0.16) quasibinary compounds with R=Dy, Ho, Er

    Energy Technology Data Exchange (ETDEWEB)

    Anikin, Maksim; Tarasov, Evgeniy; Kudrevatykh, Nikolay [Institute of Natural Sciences, Ural Federal University, Ekaterinburg 620002 (Russian Federation); Inishev, Aleksander [Institute of Metal Physics, Ekaterinburg 620137 (Russian Federation); Semkin, Mikhail; Volegov, Aleksey; Zinin, Aleksander [Institute of Natural Sciences, Ural Federal University, Ekaterinburg 620002 (Russian Federation)

    2016-11-15

    In this work the results of measurements of high field susceptibility, paraprocess susceptibility and thermal properties of R(Co{sub 1−x}Fe{sub x}){sub 2} intermetallic compounds (R=Dy, Ho, Er and x=(0−0.16)) are presented (heat capacity and magnetocaloric effect (MCE)). A magnetic structure of the Ho(Co{sub 0.88}Fe{sub 0.12}){sub 2} at 293 K and 78 K was studied by neutron powder diffraction. Some peculiarities of a high-field susceptibility were revealed at low temperatures and around the Curie point (T{sub C}). In temperature range lower than T{sub C} by (100–150) K, magnetic contributions to a zero-field heat capacity were found. Studying MCE in wide temperatures range, the large change of the entropy magnetic contribution (∆S) was observed which correlates with ∆T phenomenon. In particular, for the Er(Co{sub 0.84}Fe{sub 0.16}){sub 2} compound the ∆S value at low temperatures is six times higher than that at Curie point. The possible reasons of such behavior were discussed. - Highlights: • Magnetic and magnetocaloric properties of R(Co–Fe){sub 2} compounds have been studied. • Fe introduction induces the disorientation effect in Ho-ions magnetic ordering. • Emergence of magnetic contribution to a heat capacity at temperatures less T{sub C}. • The existence of a broad maximum on a temperature dependence of the MCE. • Direct MCE measurements at magnetic field of (0–17.5) kOe have been performed.

  12. Canted magnetic ground state of quarter-doped manganites R 0.75Ca0.25MnO3 (R  =  Y, Tb, Dy, Ho, and Er)

    Science.gov (United States)

    Sinclair, R.; Cao, H. B.; Garlea, V. O.; Lee, M.; Choi, E. S.; Dun, Z. L.; Dong, S.; Dagotto, E.; Zhou, H. D.

    2017-02-01

    Polycrystalline samples of the quarter-doped manganites R 0.75Ca0.25MnO3 (R  =  Y, Tb, Dy, Ho, and Er) were studied by x-ray diffraction and AC/DC susceptibility measurements. All five samples are orthorhombic and exhibit similar magnetic properties: enhanced ferromagnetism below T 1 (∼80 K) and a spin glass (SG) state below T SG (∼30 K). With increasing R 3+ ionic size, both T 1 and T SG generally increase. The single crystal neutron diffraction results on Tb0.75Ca0.25MnO3 revealed that the SG state is mainly composed of a short-range ordered version of a novel canted (i.e. noncollinear) antiferromagnetic spin state. Furthermore, calculations based on the double exchange model for quarter-doped manganites reveal that this new magnetic phase provides a transition state between the ferromagnetic state and the theoretically predicted spin-orthogonal stripe phase.

  13. Crystal structures of the R{sub 2}Pb{sub 3}Sn{sub 3}S{sub 12} (R = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gulay, L.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Avenue 13, 43009 Lutsk (Ukraine)], E-mail: gulay@univer.lutsk.ua; Ruda, I.P. [Department of General and Inorganic Chemistry, Volyn State University, Voli Avenue 13, 43009 Lutsk (Ukraine); Marchuk, O.V. [Department of Physical and Colloidal Chemistry, Volyn State University, Voli Avenue 13, 43009 Lutsk (Ukraine); Olekseyuk, I.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Avenue 13, 43009 Lutsk (Ukraine)

    2008-06-12

    The crystal structures of the R{sub 2}Pb{sub 3}Sn{sub 3}S{sub 12} (R = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) compounds (space group Pmc2{sub 1}, Pearson symbol oP40, a = 0.38992 (1) nm, b = 2.01175 (7) nm, c = 1.15140 (4) nm, R{sub I} 0.0785 for Ho{sub 2}Pb{sub 3}Sn{sub 3}S{sub 12}) were investigated using X-ray powder diffraction. The R{sub 1} atoms are surrounded by trigonal prisms with two additional atoms, the R{sub 2} atoms by distorted octahedra with one additional atom. The Pb{sub 1} and Pb{sub 3} atoms are surrounded by trigonal prisms with one additional atom, the Pb{sub 2} atoms by trigonal prisms with two additional atoms. Octahedral surrounding exists for Sn{sub 1} and Sn{sub 2}. The Sn{sub 3} atoms are located in trigonal bipyramids. Four or five neighbours surround the S atoms.

  14. Application of NaYF4 ∶ Yb, Er Nanoparticles as Peroxidase Mimetics in Uric Acid Detection%NaYF4∶Yb,Er纳米粒子作为过氧化物模拟酶用于尿酸检测

    Institute of Scientific and Technical Information of China (English)

    唐雨榕; 张玉; 刘睿; 苏颖颖; 吕弋

    2013-01-01

    The poly (acrylic acid) functionalized NaYF4:Yb,Er nanoparticles were found to possess intrinsic peroxidase-like activity, which could catalyze oxidization of 3 ,3',5,5'-tetramethylbiphenyl (TMB) by H2O2 to produce a colour variation. Using TMB as substrate, we systematically studied the effect of a series of conditions, such as temperature and pH, on the catalytic activity of NaYF4 : Yb,Er nanoparticles. When combined with uricase, the proposed colorimetric method could be successfully used for the determination of uric acid. Under the optimum conditions, the determination of uric acid was in the range from 1. 0xl0-5 to 2.0x10 mol/L with the detection limit down to 5. 3 × 10-6 mol/L. Moreover, the developed method was applied to detect uric acid in serum samples and the results were in good agreement with those reported by the hospital.%聚丙烯酸修饰的NaYF4∶Yb,Er纳米粒子能够有效地催化H2O2氧化3,3',5,5'-四甲基联苯胺(TMB)产生显色反应,表现出良好的过氧化物模拟酶催化活性.本研究以TMB为模型底物,研究了催化条件(温度和pH值)对催化活性的影响.同时,结合尿酸在尿酸氧化酶作用下产生H2O2的原理,建立了比色法测定血样中尿酸含量的简便方法.在最优条件下,本方法的检测范围为1.0×10-5~2.0×10-4mol/L,检出限为5.3×10-6 mol/L,并对实际样品进行测定,测定结果与临床结果一致.

  15. Optical and structural properties of (70−x−y)TeO{sub 2}-20WO{sub 3}-10Y{sub 2}O{sub 3}-xEr2O3-yYb{sub 2}O{sub 3} glasses

    Energy Technology Data Exchange (ETDEWEB)

    Prezas, P.R.; Graça, M.P.F.; Soares, M.J.; Suresh Kumar, J., E-mail: suresh@ua.pt

    2015-05-01

    Highlights: • Er{sup 3+} and Yb{sup 3+} doped heavy metal oxide tellurite glasses were prepared. • Prepared glasses can be used for optical amplifiers and spectral conversion. • FWHM of 1.54 μm emission of Er{sup 3+} is found to be about 100 nm. - Abstract: TeO{sub 2} based glasses with molar composition (70−x−y)TeO{sub 2}-20WO{sub 3}-10Y{sub 2}O{sub 3}-xEr{sub 2}O{sub 3}-yYb{sub 2}O{sub 3}, where x = 0 and 0.5 mol% and y = 0, 0.5, 1, 2 and 4 mol%, were prepared by the melt quenching technique. At room temperature, all the samples are transparent, mechanical and thermally stable. This vitreous system was found to be promising for potential applications in optical amplification, in particular in erbium doped fiber amplifiers (EDFA), Raman optical amplifiers and also in spectral conversion for applications in photovoltaic technology. The Raman spectrum of the base glass (Er0Yb0), using laser excitation of 532 nm, showed vibrational bands related to Te−O and W−O bonds. The introduction of WO{sub 3} results in a higher bandwidth relatively to SiO{sub 2} based glasses and even other TeO{sub 2} based glasses, making this vitreous system promising for Raman optical amplification. With regard to the optical analysis, an increase of the intensity of the upconversion emission with the increase of the content of the sensitizer ions Yb{sup 3+} was observed. The Er{sup 3+} emission around 1540 nm has a full width at half maximum of about 100 nm in the temperature range of 70–300 K, which is a very interesting value relatively to those reported for other glassy systems, considering optical amplification as a potential application.

  16. Solid-state synthesis and lanthanide photoluminescence of doped yttrium molybdo-antimonites, Y{sub 2−n}A{sub n}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Pr, Sm, Eu, Tb, Dy, Ho, and Er; n=0.02–2) solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Mohitkar, Shrikant A.; Vidyasagar, K., E-mail: kvsagar@iitm.ac.in

    2015-05-15

    Abstract:: Y{sub 2−n}A{sub n}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Pr, Sm, Eu, Tb, Dy, Ho, and Er; n=0.02–2) solid solutions were synthesized by a solid-state method and studied for their lanthanide photoluminescence. They show concentration dependent lanthanide photoluminescence and existence of concentration quenching phenomenon. The emission intensity and the fluorescence-lifetime are found to be highest for an optimum concentration of a given lanthanide ion in the solid solution series studied. The neat photoluminescence of A{sub 2}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Pr, Sm, Eu, Tb, Dy, Ho, and Er) compounds involves partial concentration quenching. - Highlights: • Isostructural Y{sub 2−n}A{sub n}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Pr, Sm, Eu, Tb, Dy, Ho, and Er; n=0.02–2) solid solutions have been synthesized. • Lanthanide photoluminescence of Y{sub 2−n}A{sub n}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Pr, Sm, Eu, Tb, Dy, Ho, and Er; n=0.02–2) solid solutions has been studied. • Optimum concentration of each photoluminescent dopant for Y{sub 2−n}A{sub n}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Pr, Sm, Eu, Tb, Dy, Ho, and Er; n=0.02 –2) solid solutions has been determined. • Red photoemission of Eu{sup 3+} in Y{sub 1.5}Eu{sub 0.5}Mo{sub 4}Sb{sub 2}O{sub 18} is visible to the naked eye. • Green photoemission of Tb{sup 3+} in Y{sub 1.7}Tb{sub 0.3}Mo{sub 4}Sb{sub 2}O{sub 18} is visible to the naked eye.

  17. 二价碱土金属氟化物对Er3+/Tm3+/Yb3+共掺氟氧锗酸盐玻璃热稳定性和光谱特性影响的研究%Effect of Bivalent Alkaline Earth Fluorides Introduction on Thermal Stability and Spectroscopic Properties of Er3+/Tm3+/Yb3+ Co-Doped Oxyfluorogermanate Glasses

    Institute of Scientific and Technical Information of China (English)

    胡曰博; 张新娜; 周大利; 焦清; 王荣飞; 黄劲峰; 龙晓波; 邱建备

    2012-01-01

    制备了分别含有MgF2,CaF2,SrF2或BaF2的Er3+/Tm3+/Yb3+共掺氟氧锗酸盐玻璃试样和包含BaF2纳米晶的玻璃陶瓷试样,所制备试样均具有良好的透光性.对试样的热稳定性和上转换发光特性进行了研究.通过分析试样的吸收光谱发现,随着所含二价阳离子原子量的增大,试样的紫外吸收截止波长明显向短波方向移动.结果显示:通过改变所含二价碱土金属离子的种类能够对激发光的颜色进行调节,特别值得关注的是Mg2+的影响;结果证实:通过对包含二价碱土金属的玻璃进行微晶化处理或者增加二价碱土金属的含量均能提高上转换发光的强度.%Transparent Er3+ /Tm3+ /Yb3+ co-doped oxyfluorogermanate glasses alone containing MgF2, CaF2, SrF2 or BaF2 and nano-glass-ceramics only containing BaF2 were prepared. The thermal stabilities and the up-conversion emission properties of the samples were investigated. Analyses of absorbance spectra reveal that the UV cutoff band moves slightly to shortwave band with the doping bivalent cation mass increasing. The results show that the emission color can be adjusted by changing the alkaline earth cation species in the glass matrixes, especially as Mg2+ is concerned, and the emission intensity can increase notably by heating the glass containing alkaline-earth fluoride into glass ceramic containing alkaline-earth fluoride nanocrystals or increasing the content of bivalent alkaline earth fluorides.

  18. Enhanced green upconversion by controlled ceramization of Er{sup 3+}–Yb{sup 3+} co-doped sodium niobium tellurite glass–ceramics for low temperature sensors

    Energy Technology Data Exchange (ETDEWEB)

    Suresh Kumar, J., E-mail: suresh@ua.pt; Pavani, K.; Graça, M.P.F.; Soares, M.J.

    2014-12-25

    Highlights: • Upconversion luminescence improved in glass–ceramics compared to host glass. • Judd–Ofelt and radiative parameters calculated. • NIR decay curve results concur the results of improved luminescence. • Temperature dependent upconversion support the use of materials for sensors. - Abstract: Tellurite based glasses are well-known for their upconversion properties besides having a disadvantage of low mechanical strength dragging them away from practical applications. The present work deals with preparation of sodium niobium tellurite (SNT) glasses using melt quenching method, in which small quantities of boron and silicon in the form of oxides are added to improve their mechanical properties. Controlled heat treatment is performed to ceramize the prepared glasses based on the thermal data given by DTA. XRD and SEM profiles of the glass–ceramics which confirmed the formation of crystalline monoclinic Sodium Tellurium Niobium Oxide (Na{sub 1.4}Nb{sub 3}Te{sub 4.9}O{sub 18}) phase (JCPDS card No. 04–011-7556). Upconversion measurements in the visible region were made for the prepared Er{sup 3+}–Yb{sup 3+} co-doped glasses and glass–ceramics with 980 nm laser excitation varying the laser power and concentration of Er{sup 3+} ions. Results showed that the upconversion luminescence intensity was enhanced by ten times in SNT glass–ceramics compared to that in the SNT glasses. Decay curves give evidence of high performance of glass–ceramics compared to glasses due to ceramization and structural changes. Temperature dependent visible upconversion was performed to test the ability of efficient SNT glass–ceramic at low temperatures and variation of upconversion intensities was studied.

  19. Enhanced near-infrared response of a-Si:H solar cells with {beta}-NaYF{sub 4}:Yb{sup 3+} (18%), Er{sup 3+} (2%) upconversion phosphors

    Energy Technology Data Exchange (ETDEWEB)

    de Wild, J.; Rath, J.K.; Meijerink, A.; van Sark, W.G.J.H.M.; Schropp, R.E.I. [Utrecht University, Faculty of Science, Debye Institute for Nanomaterials Science, PO Box 80000, 3508 TA Utrecht (Netherlands)

    2010-12-15

    A near-infrared to visible upconversion phosphor ({beta}-NaYF{sub 4}:Yb{sup 3+} (18%), Er{sup 3+} (2%)) has been applied at the back of a thin film hydrogenated amorphous silicon (a-Si:H) solar cell in combination with a white back reflector to investigate its response to sub-bandgap infrared irradiation. Current-voltage measurements were performed on the solar cells. A maximum current enhancement of 6.2 {mu}A was measured on illumination with a 980 nm diode laser at 28 mW. This corresponds to an external quantum efficiency (EQE) of 0.03% of the solar cell. A small part, 0.01%, was due to the direct absorption of sub-bandgap radiation but the larger part originates from upconversion. These experiments constitute a proof-of-principle for the utilization of photon upconversion in thin film solar cells. A close match between the non-linear behavior of the upconversion material and the EQE was found by varying the intensity of the laser light. (author)

  20. Twinned CsLn{sub 2}F{sub 7} compounds (Ln=Nd, Gd, Tb, Er, Yb). The role of a highly symmetrical cation lattice with an arrangement analogous to the Laves phase MgZn{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Friese, Karen [Forschungszentrum Juelich GmbH, Juelich (Germany). Juelich Centre for Neutron Science-2; Khaidukov, Nicholas [Kurnakov Institute of General and Inorganic Chemistry, Moscow (Russian Federation); Grzechnik, Andrzej [RWTH Aachen Univ. (Germany). Inst. for Crystallography

    2016-07-01

    The occurrence of twinning can often be related to higher symmetrical structures. Fluorides are frequently twinned due to their close relation to high symmetry structures like fluoride, tysonite or pyrochlores. The series of compounds CsLn{sub 2}F{sub 7} is no exception. We refined the structures of the twinned compounds with Ln=Nd, Gd, Tb, Er, Yb in space group P112{sub 1}/b. An analysis of the pseudosymmetry of the resulting structures shows a highly symmetrical cation partial structure with a cation distribution similar to the one in the hexagonal Laves phase MgZn{sub 2}. Several other compounds ALn{sub 2}F{sub 7}, which have been described in the literature, show a similar cation array. The diversity of different space groups which have been reported for ALn{sub 2}F{sub 7} compounds can be better understood using group-subgroup relationships assuming the hypothetical structure of the cation array with space group P6{sub 3}/mmc as aristotype. Furthermore, the twinning is easily understood on the basis of the lost symmetry operations in the symmetry reduction from point group 6/mmm, e.g. to 2/m in the case of the CsLn{sub 2}F{sub 7} compounds.

  1. Yb{sup 3+}-Er{sup 3+} co-doped sol-gel transparent nano-glass-ceramics containing NaYF{sub 4} nanocrystals for tuneable up-conversion phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Yanes, A.C. [Dpto. Fisica Basica, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain)], E-mail: ayanesh@ull.es; Santana-Alonso, A. [Dpto. Fisica Basica, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain); Mendez-Ramos, J. [Dpto. Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain); Castillo, J. del [Dpto. Fisica Basica, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain); Rodriguez, V.D. [Dpto. Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain)

    2009-07-08

    Transparent nano-glass-ceramics containing Yb{sup 3+}-Er{sup 3+} co-doped NaYF{sub 4} nanocrystals have been successfully developed for the first time by thermal treatment of precursor bulk glasses obtained by sol-gel technique. Precipitation of NaYF{sub 4} nanocrystals has been confirmed by X-ray diffraction measurements and their sizes have been determined by Scherrer's equation. Luminescence measurements confirm the partition of rare-earth ions in NaYF{sub 4} nanocrystals. Visible up-conversion luminescence has been obtained under infrared excitation at 980 nm. Up-conversion mechanisms have been discussed and the ratio between red and green up-conversion emission bands can be varied as a function of temperature of heat treatment and pump power resulting in colour tuneable up-conversion phosphors with applications in optical integrated devices. Colour tuneability has been also analyzed and quantified in terms of CIE standard chromaticity diagram.

  2. S-type Er-Yb Co-doped Phosphate Glass Waveguide Amplifier Integrated with Cascaded Multilayer Medium Thin Film Filter

    Institute of Scientific and Technical Information of China (English)

    CHEN Hai-yan; DAI Ji-zhi; LIU Yong-zhi

    2004-01-01

    A new S-type of erbium-ytterbium co-doped phosphate glass waveguide amplifier integrated with cascaded multilayer medium thin film filter is proposed,this S-type geometry waveguide structure is used to achieve a long path in a compact chip,and obtained higher gain with lower Er-doped concentration. The cascaded multilayer medium thin film filter is utilized to achieve a broader flattening gain bandwidth.The intrinsical gain spectrum is obtained by solving rate and power propagation equations,the effect of transmittance spectrum of thin film filter on flattening gain is discussed.

  3. BaFCl晶体中三价稀土离子Sm3+、Eu3+、Gd3+、Ho3+、Er3+和Yb3+的电荷转移激发%Charge Transfer Excitation of Rare Earth Ions (Sm3+, Eu3+, Gtl2+, Ho3+, Er3+ and Yb3+) Emission in BaFCl Crystal

    Institute of Scientific and Technical Information of China (English)

    苏勉曾; 孙小平

    1986-01-01

    @@ 1962年Jфrgensen[1]提出了精细电子自旋配对能理论(RESPET),计算由配体提供一个电子、将具有4fq基态的Ln3+还原为具有4fq+1的Ln2+这个电荷转移过程(CT)的能量变化.计算公式为Jфrgensen指出了公式中各参数的意义,并给出了各稀土离子的N(S)、M(L)和P(S,L,J)等系数的值[2,3].我们合成了Sm3+、Eu3+、Gd3+、Ho3+、Er3+和yb3+离子激活的六种BaFCl晶体,测定了它们的激发光谱(图1).由光谱数据确定了它们的电荷转移带(CTS)的波长和波数(另一报告已证明Eu 3+的CTS位于242nm[4]),利用公式(1)对以上各三价希土离子的电荷转移带的能量进行了计算.

  4. 10  GHz pulse repetition rate Er:Yb:glass laser modelocked with quantum dot semiconductor saturable absorber mirror.

    Science.gov (United States)

    Resan, B; Kurmulis, S; Zhang, Z Y; Oehler, A E H; Markovic, V; Mangold, M; Südmeyer, T; Keller, U; Hogg, R A; Weingarten, K J

    2016-05-10

    Semiconductor saturable absorber mirror (SESAM) modelocked high pulse repetition rate (≥10  GHz) diode-pumped solid-state lasers are proven as an enabling technology for high data rate coherent communication systems owing to their low noise and high pulse-to-pulse optical phase-coherence. Compared to quantum well, quantum dot (QD)-based SESAMs offer potential advantages to such laser systems in terms of reduced saturation fluence, broader bandwidth, and wavelength flexibility. Here, we describe the first 10 GHz pulse repetition rate QD-SESAM modelocked laser at 1.55 μm, exhibiting 2 ps pulse width from an Er-doped glass oscillator (ERGO). The 10 GHz ERGO laser is modelocked with InAs/GaAs QD-SESAM with saturation fluence as low as 9  μJ/cm2.

  5. Double symmetry breaking in TmFe{sub 4}Ge{sub 2} compared to RFe{sub 4}Ge{sub 2} (R=Y, Lu, Er, Ho, Dy) magnetic behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Schobinger-Papamantellos, P., E-mail: Schobinger@mat.ethz.ch [Laboratory of Crystallography, ETH-Zürich, 8093 Zürich (Switzerland); Buschow, K.H.J. [Van der Waals-Zeeman Institute, University of Amsterdam, NL-1018 XE (Netherlands); Rodríguez-Carvajal, J. [Institut Laue-Langevin, 156X, 38042 Grenoble Cédex (France)

    2014-04-15

    TmFe4Ge{sub 2} undergoes a double magneto-elastic first order transition at T{sub N},T{sub c} where the high temperature (HT) tetragonal phase disproportionate into two distinct orthorhombic low temperature (LT) phases with commensurate and incommensurate magnetic wave vectors respectively: P4{sub 2}/mnm(HT)T{sub N},T{sub c}→Cmmmq{sub 1}=(0,1/2 ,0)+Pnnm(q{sub 2}=(0,q{sub y},0),q{sub y}≈2/11(LT) Neutron diffraction shows the relative portions of the LT Cmmm and Pnnm competing phases change linearly with T. The amount of the majority HT phase Pnnm (54% at 30 K) decreases linearly to 30% down to 10 K in favour of the Cmmm phase that dominates the range 26–1.5 K. The Tm moments point along the c-axis in both phases while the Fe moments have canted arrangements. The μ{sub Tm}=3.54(3) μ{sub B}/atom at 1.5 K is strongly reduced below the Tm{sup 3+} free ion value g{sub J}J=7 μ{sub B} for the q{sub 1} phase. The q{sub 2} phase corresponds to a 3D canted sinusoidal arrangement. The results are summarised on a phase diagram and compared to the findings in RFe{sub 4}Ge{sub 2} (R=Y, Lu, Er, Ho, Dy) that are reviewed. The multitude of transition paths occurring in those systems arise from the competing magnetoelastic mechanisms involving the R-crystal field anisotropy, the exchange interactions R–R, R–Fe, Fe–Fe of the two sublattices and their coupling to the lattice strain. The geometrical frustration emerging from the compact tetrahedral Fe arrangement with antiferromagnetic interactions leads to 2D and 3D canted, incommensurate and non-magnetic states. The Cmmm transition is triggered by dominating R–R and R–Fe interactions becoming stronger at LT while the Pnnm phase is promoted by Fe–Fe and R–Fe interactions that prevail at HT. Included is also the magnetic structure of the ferromagnetic impurity phase Fe{sub 3}Ge. - Highlights: • Magnetic phase diagram of tetragonal TmFe{sub 4}Ge{sub 2} compound studied by neutron diffraction. • Unusual first

  6. Synthesis and characterization of the novel rare earth orthophosphates Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Schildhammer, Daniel; Petschnig, Lucas L.; Fuhrmann, Gerda; Heymann, Gunter; Schottenberger, Herwig; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie; Tribus, Martina [Innsbruck Univ. (Austria). Inst. fuer Mineralogie und Petrographie

    2016-02-01

    The new mixed rare earth (RE) orthophosphates Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} were synthesized by a classical solid state reaction in an electrical furnace at 1200 C. As starting materials, the corresponding rare earth oxides and diammonium hydrogen phosphate were used. The powder diffraction analyses revealed that the new compounds Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} crystallize in a zircon-type structure being isostructural with the rare earth orthophosphate YPO{sub 4}. Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} crystallize in the tetragonal space group I4{sub 1}/amd (no. 141) with four formula units in the unit cell. The structural parameters based on Rietveld refinements are a = 687.27(2), c = 601.50(2) pm, V = 0.28412(1) nm{sup 3}, R{sub p} = 0.0143, and R{sub wp} = 0.0186 (all data) for Y{sub 0.5}Er{sub 0.5}PO{sub 4} and a = 684.61(2), c = 599.31(2) pm, V = 0.28089(2) nm{sup 3}, R{sub p} = 0.0242, and R{sub wp} = 0.0313 (all data) for Y{sub 0.5}Yb{sub 0.5}PO{sub 4}. Furthermore, the structure of Y{sub 0.5}Er{sub 0.5}PO{sub 4} was refined from single-crystal X-ray diffraction data: a = 687.78(5), c = 601.85(4) pm, V = 0.28470(5) nm{sup 3}, R{sub 1} = 0.0165, and wR{sub 2} = 0.0385 (all data). In both compounds, the rare earth metal ions are eightfold coordinated by oxygen atoms, forming two unique interlocking tetrahedra with two individual RE-O distances. The tetrahedral phosphate groups [PO{sub 4}]{sup 3-} are slightly distorted in both compounds. The individual rare earth ions share a common position (Wyckoff site 4a). The presence of two rare earth ions in the structures of the new orthophosphates Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} was additionally confirmed by single-crystal EDX spectroscopy revealing a ratio of 1:1.

  7. 一种上转换白光荧光粉的制备与发光性能研究%Preparation and Up-Conversion Luminescence Properties of White AlF3-YbF3 :Er3+/Tm3+ Phosphors

    Institute of Scientific and Technical Information of China (English)

    张树全; 王华; 李洁; 周禾丰; 许并社

    2012-01-01

    采用高温固相法制备了上转换白光荧光粉AlF3-YbF3:Er3 +/Tm3+.通过XRD物相分析可知:上转换白光荧光粉AlF3 -YbF3:Er3+/Tm3+是由三方AlF3相和正交YbF3相组成;利用发射光谱研究了该荧光粉的上转换发光性能,并且分析了当固定Er3+离子掺杂浓度时,Tm3+离子掺杂浓度对上转换白光荧光粉AlF3-YbF3:Er3+/Tm3+色度的影响,进而提出其上转换能量传递机制.结果表明:在980 nm激光激发下,波长为410 nm的紫光峰、550 nm的绿光峰和660 nm的红光峰分别对应于荧光粉中Er3+离子的2H9/2 →4I15/2,4S3/2→4I15/2和4F9/2→4I15/2能级的跃迁,而波长为360 nm的紫外光峰、450 nm的蓝光峰、700 nm的红光峰,分别对应于荧光粉中Tm3离子的1D2→3H6,1G4→3H6和1G4 →3F4能级的跃迁,Er3+离子发出的光与Tm3+离子发出的光最终混合成色坐标为x =0.32,y=0.36的白光.此外,通过980 nm半导体激光器和EPM 2000 Dual-channel Joulemeter/Power meter测得该荧光粉最大上转换效率为6.90%.%A1F3 -YbF3: Er3+ was prepared by high temperature solid state reaction. The crystal structures of the phosphors were characterized by means of X-ray diffraction ( XRD). It could be seen from X-ray diffraction that the white up-conversion phosphor A1F3-YbF3; Er3+ /Tm3+ contained rhombohedra A1F3 phase and orthorhombic YbF3 phase. The conversion energy transfer mechanism of the phosphors and the concentration effect of Tm3+ on color coordinates of phosphors were studied through the emission spectra of the phosphor. The results showed that under 980 nm laser excitation, the violet peak (410 nm) , green peaks (550nm) and red peaks (660 nm) were due to 2 H9/2 →4I15/2, 4S3/2→4I15/25/2 and 4F9/2→4I15/2 energy level transition of the Er3+ ions, and the UV peaks ( 360 nm) , blue peaks(450 nm) and red peaks(700 nm) were corresponding to 1D2 → 3H6 , G4 → H6 and G4 →3F4 energy levels transition of Tm3+ ions. Finally, the blue peak, green peaks and

  8. Yb-doped Gd2O2CO3: Structure, microstructure, thermal and magnetic behaviour

    Science.gov (United States)

    Artini, Cristina; Locardi, Federico; Pani, Marcella; Nelli, Ilaria; Caglieris, Federico; Masini, Roberto; Plaisier, Jasper Rikkert; Costa, Giorgio Andrea

    2017-04-01

    Structural and microstructural features, as well as thermal and magnetic properties of Yb-doped Gd2O2CO3, were investigated with the aim to clarify the location and the oxidation state of Yb within the structure, and its role in driving the extent of the (Gd1-xYbx)2O2CO3 solid solution. Yb is found in the 3+ oxidation state and it enters the structure only at the rare earth atomic site; the solubility limit results to be located in the close vicinity of x=0.25, and thermal analyses reveal a linear decrease of the decomposition temperature with increasing the Yb amount, in agreement with literature data. The structural analysis allows to exclude long-range clusterization of Yb and Gd, since both rare earths randomly distribute over the 4f atomic position, but relying on the results of the microstructural analysis, the presence of compositional inhomogenities at the local scale cannot be excluded. Not all the structural forms are documented for the pure rare earth dioxycarbonates [1]; in particular, while form I exists for each lanthanide ion, form II is stable only for the largest ones (from La to Dy); moreover, even if II-Ho2O2CO3 (rHo3+ CN8=1.015 Å [6]) is not reported to be stable, the existence of II-Y2O2CO3 (rY3+ CN8=1.019 Å [6]) has been claimed [7]. Based on the described evidence, the stability of hexagonal Yb-doped Gd2O2CO3 is not expected along the whole compositional range. As a general remark, not all the rare earth mixed dioxycarbonates exist: (Ce, Gd)2O2CO3, for instance, could not be obtained at any composition [8]; moreover, all the structural forms can be observed only in some mixed systems, such as for example (Gd, Nd)2O2CO3, by varying temperature and tuning the composition [9]. Rare earth dioxycarbonates are studied mainly for their CO2 sensing properties [10,11], and for their emission when properly doped with a luminescent lanthanide ion [12-17]. Recently, a study of this research group [18] revealed in Gd2O2CO3:4% Yb a phenomenon of

  9. Matrix-induced synthesis and photoluminescence of M{sub 3}Ln(VO{sub 4}){sub 3}:RE (M Ca, Sr, Ba; Ln = Y, Gd; RE = Eu{sup 3+}, Dy{sup 3+}, Er{sup 3+}) phosphors by hybrid precursors

    Energy Technology Data Exchange (ETDEWEB)

    Su Xueqing [Department of Chemistry, Tongji University, Shanghai 200092 (China); Yan, Bing [Department of Chemistry, Tongji University, Shanghai 200092 (China)]. E-mail: byan@tongji.edu.cn

    2006-09-14

    Using rare earth coordination polymers with salicylic acid as precursors, composing with the polyethylene glycol (PEG) as dispersing media, the phosphor particles of M{sub 3}Ln(VO{sub 4}){sub 3}:RE (M = Ca, Sr, Ba; Ln = Y, Gd; RE Eu{sup 3+}, Dy{sup 3+}, Er{sup 3+}) were firstly synthesized via a novel modified in situ chemical co-precipitation technology. Their micromorphology and particles have been analyzed by X-ray powder diffraction (XRD) and scanning electronic microscope (SEM), which indicate that these materials have the micrometer size. And all the characteristic transitions of the doped rare earth ions can be detected in all the host lattices.

  10. Hetero-metallic {3d-4f-5d} complexes: preparation and magnetic behavior of trinuclear [(L(Me2)Ni-Ln){W(CN)(8)}] compounds (Ln = Gd, Tb, Dy, Ho, Er, Y; L(Me2) = Schiff base) and variable SMM characteristics for the Tb derivative.

    Science.gov (United States)

    Sutter, Jean-Pascal; Dhers, Sébastien; Rajamani, Raghunathan; Ramasesha, S; Costes, Jean-Pierre; Duhayon, Carine; Vendier, Laure

    2009-07-06

    Assembling bimetallic {Ni-Ln}(3+) units and {W(CN)(8)}(3-) is shown to be an efficient route toward heteronuclear {3d-4f-5d} compounds. The reaction of either the binuclear [{L(Me2)Ni(H(2)O)(2)}{Ln(NO(3))(3)}] complexes or their mononuclear components [L(Me2)Ni] and Ln(NO(3))(3) with (HNBu(3))(3){W(CN)(8)} in dmf followed by diffusion of tetrahydrofuran yielded the trinuclear [{L(Me2)NiLn}{W(CN)(8)}] compounds 1 (Ln = Y), 2a,b (Gd), 3a,b (Tb), 4 (Dy), 5 (Ho), and 6 (Er) as crystalline materials. All of the derivatives possess the trinuclear core resulting from the linkage of the {W(CN)(8)} to the Ni center of the {Ni-Ln} unit. Differences are found in the solvent molecules acting as ligands and/or in the lattice depending on the crystallization conditions. For all the compounds ferromagnetic {Ni-W} and {Ni-Ln} (Ln = Gd, Tb, Dy, and Er} interactions are operative resulting in high spin ground states. Parameterization of the magnetic behaviors for the Y and Gd derivatives confirmed the strong cyano-mediated {Ni-W} interaction (J(NiW) = 27.1 and 28.5 cm(-1)) compared to the {Ni-Gd} interaction (J(NiGd) = 2.17 cm(-1)). The characteristic features for slow relaxation of the magnetization are observed for two Tb derivatives, but these are modulated by the crystal phase. Analysis of the frequency dependence of the alternating current susceptibility data yielded U(eff)/k(B) = 15.3 K and tau(0) = 4.5 x 10(-7) s for one derivative whereas no maxima of chi(M)'' appear above 2 K for the second one.

  11. LiDy(PO34

    Directory of Open Access Journals (Sweden)

    Fathia Chehimi-Moumen

    2008-07-01

    Full Text Available Single crystals of lithium dysprosium polyphosphate, LiDy(PO34, were prepared by the flux method. The atomic arrangement is built up by infinite (PO3n chains extending along the b axis. Dy3+ and Li+ cations alternate in the middle of four such chains, with Dy...Li distances of 3.54 (1 and 3.48 (1 Å. The DyO8 dodecahedra and LiO4 tetrahedra deviate significantly from the ideal geometry. Both Dy and Li occupy special positions (Wyckoff position 4e, site symmetry 2.

  12. New strategy to construct single-ion magnets: a unique Dy@Zn₆ cluster exhibiting slow magnetic relaxation.

    Science.gov (United States)

    Xiong, Gang; Qin, Xiang-Yang; Shi, Peng-Fei; Hou, Yin-Ling; Cui, Jian-Zhong; Zhao, Bin

    2014-04-25

    Two unique heptanuclear clusters Ln@Zn6 (Ln = Dy (1), Er (2)) were structurally and magnetically characterized. Each Dy(3+)/Er(3+) is located in a nona-coordinate D(3h) coordination environment, and is encapsulated in a diamagnetic Zn6 cage. Compound 1 exhibits single-ion magnetic behavior, and is the first example of a single-ion magnet (SIM) constructed through embedding one magnetic anisotropic metal ion into a diamagnetic cage.

  13. Luminescence studies on Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses for WLED applications

    Science.gov (United States)

    Vijayakumar, M.; Uma, V.; Arunkumar, S.; Marimuthu, K.

    2015-06-01

    Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses have been prepared and optically characterized using absorption, luminescence and decay measurements. The Nephelauxetic ratios (β), Bonding parameters (δ) and Judd-Ofelt (JO) intensity parameters Ωλ (λ = 2, 4 and 6) were calculated to study the nature of the environment around the RE3+ ions in the prepared glasses. The yellow to blue (Y/B) intensity ratio and the chromaticity color coordinates were calculated from the luminescence measurements. The lifetimes of the 4F9/2 excited level were measured using decay curves and is found to decrease in the Dy3+:Eu3+ co-doped glass due to the occurrence of resonant energy transfer between Dy3+-Eu3+ ions and the non-exponential decay rates have been fitted with Inokuti-Hirayama (IH) model. The decay curves are well fitted for S= 6 suggesting that the interaction between active ions for the energy transfer is of dipole-dipole nature.

  14. Sulfate Exchange of the Nitrate-Type Layered Hydroxide Nanosheets of Ln2(OH)5NO3· nH2O for Better Dispersed and Multi-color Luminescent Ln2O3 Nanophosphors (Ln = Y0.98RE0.02, RE = Pr, Sm, Eu, Tb, Dy, Ho, Er, and Tm)

    Science.gov (United States)

    Wu, Xiaoli; Liu, Weigang; Li, Ji-Guang; Zhu, Qi; Li, Xiaodong; Sun, Xudong

    2016-07-01

    Through restricting thickness growth by performing coprecipitation at the freezing temperature of ~4 °C, solid-solution nanosheets (up to 5-nm thick) of the Ln2(OH)5NO3· nH2O layered hydroxide (Ln = Y0.98RE0.02; RE = Pr, Sm, Eu, Tb, Dy, Ho, Er, and Tm, respectively) were directly synthesized without performing conventional exfoliation. In situ exchange of the interlayer NO3 - with SO4 2- produced a sulfate derivative [Ln2(OH)5(SO4)0.5· nH2O] of the same layered structure and two-dimensional crystallite morphology but substantially contracted d 002 basal spacing (from ~0.886 to 0.841 nm). The sulfate derivative was systematically compared against its nitrate parent in terms of crystal structure and phase/morphology evolution upon heating. It is shown that the interlayer SO4 2-, owing to its bonding with the hydroxide main layer, significantly raises the decomposition temperature from ~600 to 1000 °C to yield remarkably better dispersed oxide nanopowders via a monoclinic Ln2O2SO4 intermediate. The resultant (Y0.98RE0.02)2O3 nanophosphors were studied for their photoluminescence to show that the emission color, depending on RE3+, spans a wide range in the Commission Internationale de l'Eclairage (CIE) chromaticity diagram, from blue to deep red via green, yellow, orange, and orange red.

  15. Excitation and luminescence of Dy3+ions in PbO-P2O5-Ga2O3 glass system

    Institute of Scientific and Technical Information of China (English)

    M. Sołtys; L.Żur; J. Pisarska; W.A. Pisarski

    2014-01-01

    Lead phosphate glasses singly doped with Dy3+ions were studied. The samples were prepared in a glove box in order to eliminate hydroxyl groups. Local structures were examined using FT-IR. Excitation and luminescence spectra for Dy3+ions in inves-tigated lead phosphate glasses were registered. Luminescence intensity ratio Y/B related to 4F9/2→6HJ/2 (where J=15, 13) transitions was determined and luminescence lifetime (τm) for the 4F9/2 state of Dy3+ions were also measured.

  16. Physical Properties of RE2 Ti3 Si4 (RE=Gd,Tb,Dy,Ho and Er)from First-principles Calculations%RE2 Ti3Si4(RE=Gd,Tb,Dy,Ho和Er)物理性质的第一性原理研究

    Institute of Scientific and Technical Information of China (English)

    陶小马; 陈晨; 郭子凤; 王戎丞; 陈红梅; 欧阳义芳

    2014-01-01

    【目的】对 RE2 Ti3 Si4(RE=Gd,Tb,Dy,Ho和 Er)的物理性能进行研究。【方法】利用基于密度泛函的第一性原理方法对 RE2 Ti3 Si4(RE=Gd,Tb,Dy,Ho 和 Er)的结构性质、电子结构、力学以及热力学性质进行计算。对RE2 Ti3 Si4单晶的弹性常数,多晶的体积模量、剪切模量和杨氏模量都进行了计算。利用准谐的德拜模型计算获得了体积模量、比热熔和热膨胀系数随着温度和压强的变化,并进行了相关的讨论。【结果】RE2 Ti3 Si4的晶格常数计算值和实验值吻合较好。【结论】形成焓的计算值随着稀土元素原子序数的增加而呈现微小的下降趋势,这表明化合物的稳定性随着原子序数的增加而加强。电子态密度显示在费米能级之下,Ti-3d和 RE-5d的态密度有着很强的杂化现象。%Objective]Physical properties of the RE2 Ti3 Si4 (RE=Gd,Tb,Dy,Ho and Er)are studied.[Methods]We present the structural,electronic structure,mechanical and thermody-namic properties of the RE2 Ti3 Si4 (RE=Gd,Tb,Dy,Ho and Er)by using first-principles calcu-lations based on the density functional theory (DFT).[Results]The calculated lattice constants of RE2 Ti3 Si4 are all in good agreement with experimental data.The single crystal elastic con-stants of RE2 Ti3 Si4 have been calculated,and the bulk,shear and Young's modulus are all been estimated in this work.Finally,using a quasi-harmonic Debye model,the bulk modulus,heat ca-pacity,and coefficient of thermal expansion have also been obtained and discussed.[Conclusion]The calculated formation enthalpies of the RE2 Ti3 Si4 show tiny decline trend with the increas-ing atomic number,which indicates that phase stability of RE2 Ti3 Si4 enhance slightly with in-creasing atomic number.The electronic densities of states indicate that Ti-3d and RE-5d peaks show strong hybridization below the Fermi level.

  17. Micro-crystallization and spectroscopic properties of Er, Yb:RAl-borates (R=Y, Gd) obtained in RAl3(BO3)4-K2Mo3O10-B2O3-R2O3 and RAl3(BO3)4-B2O3 systems

    Science.gov (United States)

    Naprasnikov, D. A.; Maltsev, V. V.; Leonyuk, N. I.; Gorbachenya, K. N.; Kurilchik, S. V.; Kisel, V. E.; Kuleshov, N. V.

    2017-01-01

    The spontaneous YAl3(BO3)4 (YAB) and GdAl3(BO3)4 (GdAB) crystals (of nominal composition and co-doped with Er and Yb) up to 4-5 mm in length were grown from high-temperature solutions using K2Mo3O10 based fluxes in the temperature range of 1120-900 °C. Glass-ceramic composites based on the YAB and GdAB micro-crystals have been prepared by quenching YAB-B2O3 and GdAB-B2O3 melts and characterized by X-ray diffraction and spectroscopic methods. The vitrified melt was shown to contain micro- and nano-crystalline rare-earth borate phases. Their distribution over the composites has been investigated by electron microscopy and three-dimensional X-ray tomography. The absorption spectra of these materials co-doped with erbium and ytterbium as well as luminescence spectrum were demonstrated.

  18. 镱铒共掺光纤放大器真空下温度对增益的影响%Effect of temperature on the gain in Er3+/Yb3+co-doped optical fiber amplifier under vacuum environment

    Institute of Scientific and Technical Information of China (English)

    李伢琴; 单欣; 郧建平; 艾勇

    2014-01-01

    The relation of the fiber amplifier gain and emission cross section and absorption cross section of doped fi-ber,the thermal performance of the optical fiber amplifier under vacuum environment are theoretically analyzed.Ex-perimental results show that the gain change is 0.0076 dB /℃under vacuum environment when the input optical sig-nal is at 1550 nm.When the fiber amplifier works 5 minutes at 55 ℃under vacuum environment,Er/Yb co-doped fi-ber temperature drops to 76 ℃ from 106 ℃,the output power fluctuation is less than 10 mW.%理论分析了光纤放大器的增益与掺杂光纤发射截面和吸收截面的关系,真空环境下的光纤放大器的散热性能。实验表明,真空环境下,输入光信号为1550 nm 的情况下,增益以0.0076 dB/℃变化,真空55℃工作5 min,散热措施能使镱铒共掺光纤温度从106℃下降至76℃,输出功率在波动小于10 mW。

  19. Activation cross sections of the {sup nat}Yb(p,xn){sup 169}Lu reaction for indirect production of the therapeutic radionuclide {sup 169}Yb

    Energy Technology Data Exchange (ETDEWEB)

    Tarkanyi, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), 1090 Brussels (Belgium); Takacs, S.; Ditroi, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c (Hungary); Kiraly, B. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c (Hungary)], E-mail: kiralyb@atomki.hu; Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron and Radioisotope Center (CYRIC), Tohoku University, Sendai 980-8578 (Japan); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk 249020 (Russian Federation)

    2009-09-01

    Activation cross sections of the {sup nat}Yb(p,xn){sup 169}Lu reaction have been measured for the first time up to 70 MeV to investigate the production possibility of the radionuclide {sup 169}Yb through decay of its parent {sup 169}Lu. The cross sections were measured using the stacked foil irradiation technique and gamma spectrometry. The experimental data were compared with the results of the ALICE-IPPE theoretical model code. Different production routes were compared for the internal radiotherapy related radioisotope {sup 169}Yb. Above 30 MeV proton energy the integral yield of the {sup nat}Yb(p,xn){sup 169}Lu reaction is higher than that of the earlier investigated {sup 169}Tm(p,n){sup 169}Yb, {sup 169}Tm(d,2n){sup 169}Yb, {sup nat}Er({alpha},xn){sup 169}Yb, {sup nat}Yb({alpha},x){sup 169}Lu and {sup nat}Hf(p,x){sup 169}Lu reactions at the equivalent particle energies.

  20. Dy substitution effect on the temperature dependences of magnetostriction in Pr1-x Dy x Fe1.9 alloys

    Science.gov (United States)

    Tang, Yan-Mei; Huang, Hai-Fu; Tang, Shao-Long; Du, You-Wei

    2016-11-01

    The temperature dependences of magnetostriction in Pr1-x Dy x Fe1.9 (0 ≤ x ≤ 1.0) alloys between 5 K and 300 K were investigated. An unusual decrease of magnetostriction with temperature decreasing was found in Pr-rich alloys (0 ≤ x ≤ 0.2), due to the change of the easy magnetization direction (EMD). Dy substitution reduces the magnetostriction in high-magnetic field (10 kOe ≤ H ≤ 90 kOe) at 5 K, while a small amount of Dy substitution (x = 0.05) is beneficial to increasing the magnetostriction in low-magnetic field between 10 K and 50 K. This makes the alloys a potential candidate for low temperature applications. Project supported by the National Natural Science Foundation of China (Grant No. U1232210), the Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant No. 2015GXNSFBA139020), and the Enhancement of the Basic Ability of Teachers of Guangxi Zhuang Autonomous Region, China (Grant No. KY2016YB068).

  1. Homoleptic rare earth dipyridylamides [Ln2(N(NC5H4)2)6], Ln = Ce, Nd, Sm, Ho, Er, Tm, Yb, and Sc: metal oxidation by the amine melt and in 1,2,3,4-tetrahydroquinoline with the focus of different metal activation by amalgams, liquid ammonia, and microwaves.

    Science.gov (United States)

    Müller-Buschbaum, Klaus; Quitmann, Catharina C

    2006-03-20

    Homoleptic dimeric dipyridylamide complexes of the rare earth elements are obtained by solvent-free oxidation reactions of the metals with melts of 2,2'-dipyridylamine. As the thermal stabilities of the ligand as well as the amide complexes are limiting factors in these high-temperature syntheses, several different metal activation procedures have been investigated: the formation of Ln amalgams and dissolution of the metals in liquid ammonia as well as coupling to microwaves. For comparison with a solvent that shows low solubility of the metals and products, reactions in 1,2,3,4-tetrahydroquinoline were also carried out. For all lanthanides and group 3 metals used homoleptic dimers of the formula [Ln(2)(Dpa)(6)], Ln = Ce (1), Nd (2), Sm (3), Ho (4), Er (5), Tm (6), Yb (7), and Sc (8) and Dpa- = (C5H4N)2N-, were obtained, all containing trivalent rare earth ions with a distorted square antiprismatic nitrogen coordination. Due to the large differences in the ionic radii of the metal ions, two different structure types are found that crystallize in the space groups P2(1)/c and P2(1)/n with the border of the two types being between Tm and Yb. The orientations of two 1,3/1,3-double chelating and linking dipyridylamide ligands (Dpa(-) = (C(5)H(4)N)(2)N(-)) result in different overall orientations of the dimers and thus two structure types. All compounds were identified by single-crystal X-ray analysis. Mid-IR, far IR, and Raman spectroscopy, microanalyses, and simultaneous DTA/TG as well as mass spectrometry regarding their thermal behavior were also carried out to characterize the products. Crystal data for the two types follow. Ce (1): P2(1)/n; T = 170(2) K; a = 1063.0(1), b = 1536.0(1), c = 1652.0(2) pm; beta = 101.60(1) degrees ; V = 2642.2(3) x 10(6) pm(3); R(1) for F(o) > 4sigma(F(o)) = 0.046, wR(2) = 0.120. Sc (8): P2(1)/c; T = 170(2) K; a = 1073.0(1), b = 1506.2(2), c = 1619.8(2) pm; beta = 103.16(9) degrees ; V = 2548.9(5) x 10(6) pm(3); R(1) for F(o) > 4sigma

  2. YB0 HAS LANDED

    CERN Multimedia

      On Feb 28th after a majestic descent of 90m taking 11 hours, the 2000t YB0 central wheel of CMS, containing the superconducting solenoid, gently touched down on the floor of the experimental cavern UXC55.

  3. Electronic Configuration of Yb Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Temmerman, W.M.; Szotek, Z. [Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, Cheshire (United Kingdom); Svane, A. [Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Strange, P. [Physics Department, Keele University, Keele, Staffordshire, ST5 5BG (United Kingdom); Winter, H. [INFP, Forschungszentrum Karlsruhe GmbH, Postfach 3640, D-76021 Karlsruhe (Germany); Delin, A.; Johansson, B.; Eriksson, O.; Fast, L. [Condensed Matter Theory Group, Department of Physics, University of Uppsala, Box 530, 75121 Uppsala (Sweden); Wills, J.M. [Center of Materials Science and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

    1999-11-01

    The total energy differences between divalent and trivalent configurations of Yb ions in a number of Yb compounds are studied. Two different band theoretical methods, which differ in the treatment of the localized f electrons, are used. The results show that in all Yb compounds the valence energy differences are equal to the energy needed to localize an f electron. These valence energy differences correlate with the number of f electrons hybridizing with the conduction bands in the trivalent configuration. For divalent YbS, the pressure induced f -electron delocalization implies an intermediate valency, as also indicated by experiment. {copyright} {ital 1999} {ital The American Physical Society }

  4. The Dy-Zn phase diagram

    Science.gov (United States)

    Saccone, A.; Cardinale, A. M.; Delfino, S.; Ferro, R.

    2003-03-01

    The dysprosium-zinc phase diagram has been investigated over its entire composition range by using differential thermal analysis, (DTA) metallographic analysis, X-ray powder diffraction, and electron probe microanalysis (EPMA). Seven intermetallic phases have been found and their structures confirmed. DyZn, DyZn2, Dy13Zn58, and Dy2Zn17 melt congruently at 1095 °C, 1050 °C, 930 °C, and 930 °C, respectively. DyZn3, Dy3Zn11, and DyZn12 form through peritectic reactions at 895 °C, about 900 °C and 685 °C, respectively. Four eutectic reactions occur at 850 °C and 30.0 at pct Zn (between (Dy) and DyZn), 990 °C and 60.0 at pct Zn (between DyZn and DyZn2), 885 °C and 76.0 at pct Zn (between DyZn3 and Dy3Zn11), and 875 °C and 85.0 at pct Zn (involving Dy13Zn58 and Dy2Zn17). The Dy-rich end presents a catatectic equilibrium; a degenerate invariant effect has been found in the Zn-rich region. The phase equilibria of the Dy-Zn alloys are discussed and compared with those of the other known RE-Zn systems (RE=rare earth metal) in view of the regular change in the relative stabilities of the phases across the lanthanide series

  5. YB0 SERVICES INSTALLATION COMPLETED

    CERN Multimedia

    The beauty of the completed YB0 was briefly visible at P5 as preparations continue for Tracker installation. A tremendous effort, lasting 7 months and involving more than 100 workers on the busiest days, resulted in 5700 electrical cables, 780 optical cables with 65k fibre channels, and 550 pipes laid on YB0 for HB, EB and Tracker.

  6. Comparison of spectroscopic properties of Yb:YAP and Yb:YAG crystals

    Institute of Scientific and Technical Information of China (English)

    Xiaoming He; Guangjun Zhao; Xiaodong Xu; Xionghui Zeng; Jun Xu

    2007-01-01

    The Yb:YAG and Yb:YAP crystals have been grown by Czochralski method. The absorption spectra and the fluorescence spectra of Yb:YAG and Yb:YAP crystals have been investigated. It is shown that the Yb:YAG crystal has better laser properties and smaller threshold power than Yb:YAP crystal. In addition, the absorption cross-section of the Yb:YAP crystal is 2.16 times of that of the Yb:YAG crystal,so laser diode pumped Yb:YAG lasing can be easily realized. Because YAP single crystal is anisotropic, it is provided with polarization characteristics.

  7. Concentration dependence of luminescence efficiency of Dy(3)(+) ions in strontium zinc phosphate glasses mixed with Pb3 O4.

    Science.gov (United States)

    Kumar, Valluri Ravi; Giridhar, G; Veeraiah, N

    2017-02-01

    In this work we synthesized SrO-ZnO-P2 O5 glasses mixed with Pb3 O4 (heavy metal oxide) and doped with different amounts of Dy2 O3 (0.1 to 1.0 mol%). Subsequently their emission and decay characteristics were investigated as a function of Dy2 O3 concentration. The emission spectra exhibited three principal emission bands in the visible region corresponding to (4) F9/2  → (6) H15/2 (482 nm), (6) H13/2 (574 nm) and (6) H11/2 (663 nm) transitions. With increase in the concentration of Dy2 O3 (upto 0.8 mol%) a considerable increase in the intensity of these bands was observed and, for further increase, quenching of photoluminescence (PL) output was observed. Using emission spectra, various radiative parameters were evaluated and all these parameters were found to increase with increase in Dy2 O3 concentration. The Y/B integral emission intensity ratio of Dy(3)(+) ions evaluated from these spectra exhibited a decreasing trend with increase in the Dy2 O3 concentration up to 0.8 mol%. Quenching of luminescence observed in the case of the glasses doped with 1.0 mol% is attributed to clustering of Dy(3)(+) ions. The quantitative analysis of these results together with infra-red (IR) spectral studies indicated that 0.8 mol% is the optimum concentration of Dy(3)(+) ions needed to achieve maximum luminescence efficiency. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Structural and magnetic properties of DyMn{sub 2}D{sub 6} synthesized under high deuterium pressure

    Energy Technology Data Exchange (ETDEWEB)

    Paul-Boncour, V [Laboratoire de Chimie Metallurgique des Terres Rares, CNRS, 2-8 rue H Dunant, 94320 Thiais (France); Filipek, S M; Wierzbicki, R [Institute of Physical Chemistry, PAS, Ul. Kasprzaka 44/52, 01224 Warsaw (Poland); Andre, G; Bouree, F [Laboratoire Leon Brillouin, CEA-CNRS, CEA/Saclay, 91191 Gif-sur-Yvette (France); Guillot, M [LCMI, CNRS-MPI, BP166, 38042 Grenoble Cedex 9 (France)], E-mail: paulbon@glvt-cnrs.fr

    2009-01-07

    DyMn{sub 2}D{sub 6} has been prepared by applying high gaseous deuterium pressure on DyMn{sub 2}. This phase is isostructural with other RMn{sub 2}D{sub 6} (R = Y, Er) compounds and crystallizes with a K{sub 2}PtCl{sub 6} type structure having an ordered anion and a partially disordered cation arrangement because Dy and half the Mn atoms are randomly substituted in the same 8c site. The reverse susceptibility follows a Curie-Weiss law with an effective moment of 10 {mu}{sub B} similar to that of DyMn{sub 2}. Short range magnetic order, corresponding to ferromagnetic correlations, is observed in the neutron patterns up to 10 K and can be attributed to Dy-Dy interactions. The decomposition of the deuteride into Mn and DyD{sub 2}, studied by thermal gravimetric analysis, occurs between 470 and 650 K. A further deuterium desorption takes place above 920 K.

  9. Series of edge-sharing bi-triangle Ln4 clusters with a μ4-NO3- bridge: syntheses, structures, luminescence, and the SMM behavior of the Dy4 analogue.

    Science.gov (United States)

    Zou, Hua-Hong; Wang, Rong; Chen, Zi-Lu; Liu, Dong-Cheng; Liang, Fu-Pei

    2014-02-14

    A series of Ln4 clusters, [Ln4L2(μ3-OH)2(μ4-NO3)(NO3)4(OCH3)(H2O)]·xMeCN·yMeOH (Ln = Gd (1), Tb (2), Dy (3), Ho (4), Er (5), Yb (6), L = 2-{[2-(2-hydroxy-ethoxy)-ethylimino]-methyl}-6-methoxyphenol), have been synthesized by the reaction of Ln(NO)3 and a Schiff-base ligand formed in situ. The six complexes display similar structures, with an overall metal core comprising two edge-sharing triangular Ln3 units linked by a μ4-NO3(-) bridge. The luminescence spectrum of complex 2 shows the characteristic emission of the Tb(III) ions. The magnetic susceptibility studies reveal that the Ln(III) ions are very weakly interacting in all six compounds. Frequency dependence of the ac-susceptibility was found for 3, suggesting a typical single-molecule magnet (SMM) behavior with an anisotropic barrier of 28 K.

  10. Yb:S-FAP Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Schaffers, K I

    2004-01-20

    It has recently been reported that several high power, diode-pumped laser systems have been developed based on crystals of Yb:S-FAP [Yb{sup 3+}:Sr{sub 5}(PO{sub 4}){sub 3}F]. The Mercury Laser, at Lawrence Livermore National Laboratory, is the most prominent system using Yb:S-FAP and is currently producing 23J at 5 Hz in a 15 nsec pulse, based on partial activation of the system. In addition, a regenerative amplifier is being developed at Waseda University in Japan and has produced greater than 12 mJ with high beam quality at 50Hz repetition rate. Q-peak has demonstrated 16 mJ of maximum energy/output pulse in a multi-pass, diode side-pumped amplifier and ELSA in France is implementing Yb:S-FAP in a 985 nm pump for an EDFA, producing 250 mW. Growth of high optical quality crystals of Yb:S-FAP is a challenge due to multiple crystalline defects. However, at this time, a growth process has been developed to produce high quality 3.5 cm diameter Yb:S-FAP crystals and a process is under development for producing 6.5 cm diameter crystals.

  11. White light simulation and luminescence studies on Dy{sup 3+} doped Zinc borophosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, R. [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India); Venkataiah, G. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Marimuthu, K., E-mail: mari_ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India)

    2015-01-15

    The Dy{sup 3+} doped Zinc borophosphate glasses with the chemical composition (79-x)B{sub 2}O{sub 3}+xP{sub 2}O{sub 5}+10Li{sub 2}O+10ZnO+1Dy{sub 2}O{sub 3} (where x=0, 10, 20, 30 and 50 in wt%) have been prepared by melt quenching technique. The prepared glass samples were characterized through optical absorption, emission and decay measurements. The bonding parameters, optical band gap and Urbach's energy values were calculated from the optical absorption spectra to explore the bonding nature of the Dy–O metal ligand and electronic band structure of the studied glasses. Judd–Ofelt (JO) intensity parameters were calculated from the absorption spectra by using the JO theory and it gives information about symmetry of the ligand environment around the Dy{sup 3+} ion site. The Y/B intensity ratio and radiative properties were obtained from the emission spectra and the results were compared with the reported literature. The x, y chromaticity color coordinates of the studied glasses were analyzed using a CIE 1931 color chromaticity diagram and found that the x, y coordinates lie in the white light region. The decay curve measurements of the prepared glasses exhibit non-exponential behavior and are well fitted to Inokuti–Hirayama (IH) model to understand the energy transfer mechanism between Dy{sup 3+} ions. The Q, R{sub 0} and C{sub DA} values of the prepared Dy{sup 3+} doped glasses were obtained from the IH model and the results were discussed and compared with the reported literature.

  12. Activation cross sections of proton and deuteron induced nuclear reactions on holmium and erbium, related to the production of $^{161}$Er and $^{160}$Er medical isotopes

    CERN Document Server

    Tárkányi, F; Takács, S; Hermanne, A; Baba, M

    2016-01-01

    Experimental excitation functions for long-lived products in proton induced reactions were measured with the activation method in the 37-65 MeV energy range on natural holmium. Stacked foil irradiation technique and high resolution gamma spectrometry were used in order to measure cross-section data for the production of $^{161}$Er, $^{160}$Er and $^{159,157}$Dy. For comparison of the production routes of medically related $^{161}$Er and $^{160}$Er radioisotopes new experimental cross section data were deduced for the $^{162}$Er(p,x)$^{161,160}$Er and $^{162}$Er(d,x)$^{161,160}$Er reactions by re-evaluating gamma-ray spectra from earlier measurements. No earlier data were found in the literature for these reactions. The experimental data are compared with results of TALYS theoretical code reported in TENDL-2015.

  13. Activation cross sections of proton and deuteron induced nuclear reactions on holmium and erbium, related to the production of (161)Er and (160)Er medical isotopes.

    Science.gov (United States)

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Baba, M

    2016-09-01

    Experimental excitation functions for long-lived products in proton induced reactions were measured with the activation method in the 37-65MeV energy range on natural holmium. Stacked foil irradiation technique and high resolution gamma spectrometry were used in order to measure cross-section data for the production of (161)Er, (160)Er and (1)(59,157)Dy. For comparison of the production routes of medically related (161)Er and (160)Er radioisotopes new experimental cross section data were deduced for the (162)Er(p,x)(161,160)Er and (162)Er(d,x)(161,160)Er reactions by re-evaluating gamma-ray spectra from earlier measurements. No earlier data were found in the literature for these reactions. The experimental data are compared with results of TALYS theoretical code reported in TENDL-2015.

  14. Cooperative emission in ion implanted Yb:YAG waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, G V; Desirena, H; De la Rosa, E [Centro de Investigaciones en Optica, Loma del Bosque 115, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Flores-Romero, E; Rickards, J; Trejo-Luna, R [Instituto de Fisica, UNAM, Apartado Postal 20364, 01000 Mexico, D. F. (Mexico); Marquez, H, E-mail: gvvazquez@cio.mx [Departamento de Optica, CICESE, Km 107 Carr. Tijuana-Ensenada, 22860 Ensenada, B. C. (Mexico)

    2011-01-01

    In this work, we report the analysis of spectroscopic properties of waveguides fabricated by ion implantation in YAG doped with Yb{sup 3+} ions. Three emission bands were detected in the blue, green and red regions under 970-nm excitation. The strong blue-green emission can be explained by a cooperative process between ytterbium ion pairs, leading to emission centered at 514 nm. The additional blue bands as well as green and red emission bands are attributed to the presence of Tm{sup 3+} and Er{sup 3+} traces. The results include absorption and emission curves as well as decay time rates.

  15. Magnetic interactions in CuII-LnIII cyclic tetranuclear complexes: is it possible to explain the occurrence of SMM behavior in CuII-TbIII and CuII-DyIII complexes?

    Science.gov (United States)

    Hamamatsu, Takefumi; Yabe, Kazuya; Towatari, Masaaki; Osa, Shutaro; Matsumoto, Naohide; Re, Nazzareno; Pochaba, Andrzej; Mrozinski, Jerzy; Gallani, Jean-Louis; Barla, Alessandro; Imperia, Paolo; Paulsen, Carley; Kappler, Jean-Paul

    2007-05-28

    An extensive series of tetranuclear CuII2LnIII2 complexes [CuIILLnIII(hfac)2]2 (with LnIII being all lanthanide(III) ions except for the radioactive PmIII) has been prepared in order to investigate the nature of the CuII-LnIII magnetic interactions and to try to answer the following question: What makes the CuII2TbIII2 and CuII2DyIII2 complexes single molecule magnets while the other complexes are not? All the complexes within this series possess a similar cyclic tetranuclear structure, in which the CuII and LnIII ions are arrayed alternately via bridges of ligand complex (CuIIL). Regular SQUID magnetometry measurements have been performed on the series. The temperature-dependent magnetic susceptibilities from 2 to 300 K and the field-dependent magnetizations from 0 to 5 T at 2 K have been measured for the CuII2LnIII2 and NiII2LnIII2 complexes, with the NiII2LnIII2 complex containing diamagnetic NiII ions being used as a reference for the evaluation of the CuII-LnIII magnetic interactions. These measurements have revealed that the interactions between CuII and LnIII ions are very weakly antiferromagnetic if Ln=Ce, Nd, Sm, Yb, ferromagnetic if Ln=Gd, Tb, Dy, Ho, Er, Tm, and negligible if Ln=La, Eu, Pr, Lu. With the same goal of better understanding the evolution of the intramolecular magnetic interactions, X-ray magnetic circular dichroism (XMCD) has also been measured on CuII2TbIII2, CuII2DyIII2, and NiII2TbIII2 complexes, either at the L- and M-edges of the metal ions or at the K-edge of the N and O atoms. Last, the CuII2TbIII2 complex exhibiting SMM behavior has received a closer examination of its low temperature magnetic properties down to 0.1 K. These particular measurements have revealed the unusual very slow setting-up of a 3D order below 0.6 K.

  16. ISOMER-SELECTED DECAY OF THE GDR IN DY-156

    NARCIS (Netherlands)

    VANSCHAGEN, JPS; HARAKEH, MN; HESSELINK, WHA; NOORMAN, RF

    1995-01-01

    The strength distribution of high-energy gamma-rays emitted in the statistical decay of the 156Dy compound nucleus, with E* = 92.5 MeV, has been measured inclusively and for selected decay pathways in which isomers in 149Dy, 151Dy and 152Dy were populated. For both spectra a deformation \\beta\\ = 0.3

  17. Synthesis of ZnO:Dy Nanopowder and Photoluminescence of Dy3+ in ZnO

    Institute of Scientific and Technical Information of China (English)

    Zhang Linli; Guo Changxin; Zhao Junjing; Hu Juntao

    2005-01-01

    A type of dysprosium-doped ZnO (ZnO:Dy) nanopowder was synthesized by high temperature calcinations. XRD was used to analyze the structure. Photoluminescence spectra were used to study the optical characteristic. PL of ZnO:Dy shows two different spectra which are broad band resulted from the defect of Dy in ZnO and sharp lines from the 4f→4f transition of isolated Dy3+ luminescence center. The emission and excitation spectra depend on the excitation wavelength and the concentration of Dy3+. The broad bands with peaks at 600 and 760 nm are attributed to the recombination from an electron of the defect Dy in ZnO to a hole in VB.

  18. DySectAPI: Scalable Prescriptive Debugging

    DEFF Research Database (Denmark)

    Jensen, Nicklas Bo; Karlsson, Sven; Quarfot Nielsen, Niklas;

    We present the DySectAPI, a tool that allow users to construct probe trees for automatic, event-driven debugging at scale. The traditional, interactive debugging model, whereby users manually step through and inspect their application, does not scale well even for current supercomputers. While...... lightweight debugging models scale well, they can currently only debug a subset of bug classes. DySectAPI fills the gap between these two approaches with a novel user-guided approach. Using both experimental results and analytical modeling we show how DySectAPI scales and can run with a low overhead...

  19. Highly Efficient Near-IR Photoluminescence of Er3+ Immobilized in Mesoporous SBA-15

    Directory of Open Access Journals (Sweden)

    Wu P

    2010-01-01

    Full Text Available Abstract SiO2 mesoporous molecular sieve SBA-15 with the incorporation of erbium ions is studied as a novel type of nanoscopic composite photoluminescent material in this paper. To enhance the photoluminescence efficiency, two schemes have been used for the incorporation of Er3+ where (1 Er3+ is ligated with bis-(perfluoromethylsulfonyl-aminate (PMS forming Er(PMSx-SBA-15 and (2 Yb3+ is codoped with Er3+ forming Yb-Er-SBA-15. As high as 11.17 × 10−21cm2 of fluorescent cross section at 1534 nm and 88 nm of “effective bandwidth” have been gained. It is a 29.3% boost in fluorescent cross section compared to what has been obtained in conventional silica. The upconversion coefficient in Yb-Er-SBA-15 is relatively small compared to that in other ordinary glass hosts. The increased fluorescent cross section and lowered upconversion coefficient could benefit for the high-gain optical amplifier. Finally, the Judd–Ofelt theory has also been used for the analyses of the optical spectra of Er(PMSx-SBA-15.

  20. Magnetocaloric properties of rare-earth substituted DyCrO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    McDannald, A. [Material Science and Engineering Department, University of Connecticut, Storrs, Connecticut 06269 (United States); Jain, M., E-mail: menka.jain@uconn.edu [Institute of Material Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

    2015-07-28

    Recently, there has been a focus on the need for efficient refrigeration technology without the use of expensive or harmful working fluids, especially at temperatures below 30 K. Solid state refrigeration, based on the magnetocaloric effect, provides a possible solution to this problem. The rare-earth chromites (RCrO{sub 3}), especially DyCrO{sub 3}, with its large magnetic moment dysprosium ion, are potential candidates for such an application. The Dy{sup 3+} ordering transition at low temperatures (<10 K) likely causes a large magnetocaloric response in this material. This study investigates the possibility of tuning the magnetocaloric properties through the use of rare-earth substitution. Both Y{sup 3+} and Ho{sup 3+} substitutions were found to decrease the magnetocaloric response by disrupting the R{sup 3+} ordering. Whereas Er{sup 3+} substitution was found to increase the magnetocaloric response, likely due to an increase in the R{sup 3+} ordering temperature. The large magnetocaloric entropy change of Er{sup 3+} substituted DyCrO{sub 3} (10.92 J/kg K with a relative cooling power of 237 J/kg at 40 kOe and 5 K) indicates that this material system is well suited for low temperature (<30 K) solid state refrigeration applications.

  1. Upconversion luminescence in Yb 3+-doped yttrium aluminum garnets

    Science.gov (United States)

    Xu, Xiaodong; Zhao, Zhiwei; Song, Pingxin; Jiang, Benxue; Zhou, Guoqing; Xu, Jun; Deng, Peizhen; Bourdet, Gilbert; Christophe Chanteloup, Jean; Zou, Ji-Ping; Fulop, Annabelle

    2005-03-01

    In this paper, we present results on upconversion luminescence performed on Yb 3+-doped yttrium aluminum garnets under 940 nm excitation. The upconversion luminescence was ascribed to Yb 3+ cooperative luminescence and the presence of rare earth impurity ions. The cooperative luminescence spectra as a function of Yb concentration were measured and the emission intensity variation with Yb concentration was discussed. Yb 3+ energy migration quenched the cooperative luminescence of Yb:YAG crystals with doping level over 15 at%.

  2. Series of isostructural planar lanthanide complexes [Ln(III)4(mu3-OH)2(mdeaH)2(piv)8] with single molecule magnet behavior for the Dy4 analogue.

    Science.gov (United States)

    Abbas, Ghulam; Lan, Yanhua; Kostakis, George E; Wernsdorfer, Wolfgang; Anson, Christopher E; Powell, Annie K

    2010-09-06

    A series of five isostructural tetranuclear lanthanide complexes of formula [Ln(4)(mu(3)-OH)(2)(mdeaH)(2)(piv)(8)], (mdeaH(2) = N-methyldiethanolamine; piv = pivalate; Ln = Tb (1), Dy (2), Ho (3), Er (4), and Tm (5)) have been synthesized and characterized. These clusters have a planar "butterfly" Ln(4) core. Magnetically, the Ln(III) ions are weakly coupled in all cases; the Dy(4) compound 2 shows Single Molecule Magnet (SMM) behavior.

  3. Structural and Magnetothermal Properties of Compounds: Yb5SixGe4-x,Sm5SixGe4-x, EuO, and Eu3O4

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Kyunghan [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    The family of R5SixGe4-x alloys demonstrates a variety of unique physical phenomena related to magneto-structural transitions associated with reversible breaking and reforming of specific bonds that can be controlled by numerous external parameters such as chemical composition, magnetic field, temperature, and pressure. Therefore, R5SixGe4-x systems have been extensively studied to uncover the mechanism of the extraordinary magneto-responsive properties including the giant magnetoresistance (GMR) and colossal magnetostriction, as well as giant magnetocaloric effect (GMCE). Until now, more than a half of possible R5SixGe4-x pseudobinary systems have been completely or partially investigated with respect to their crystallography and phase relationships (R = La, Pr, Nd, Gd, Tb, Dy, Er, Lu, Y). Still, there are other R5SixGe4-x systems (R = Ce, Sm, Ho, Tm, and Yb) that are not studied yet. Here, we report on phase relationships and structural, magnetic, and thermodynamic properties in the Yb5SixGe4-xand Sm5SixGe4-x pseudobinary systems, which may exhibit mixed valence states. The crystallography, phase relationships, and physical properties of Yb5SixGe4-x alloys with 0 ≤ x ≤ 4 have been examined by using single crystal and powder x-ray diffraction at room temperature, and dc magnetization and heat capacity measurements between 1.8 K and 400 K in magnetic fields ranging from 0 to 7 T. Unlike the majority of R5SixGe4-x systems studied to date, where R is the rare earth metal, all Yb-based germanide-silicides with the 5:4 stoichiometry crystallize in the same Gd5Si4-type structure. The magnetic properties of Yb5SixGe4-x materials are nearly composition

  4. RbYb(PO34

    Directory of Open Access Journals (Sweden)

    Hui Chen

    2013-01-01

    Full Text Available Rubidium ytterbium(III tetrakis(polyphosphate, RbYb(PO34, was synthesized by solid-state reaction. It adopts structure type IV of the MRE(PO34 (M = alkali metal and RE = rare earth metal family of compounds. The structure is composed of a three-dimensional framework made up from double spiral polyphosphate chains parallel to [10-1] and irregular [YbO8] polyhedra. There are eight PO4 tetrahedra in the repeat unit of the polyphosphate chains. The Rb+ cation is located in channels extending along [100] that are delimited by the three-dimensional framework. It is surrounded by 11 O atoms, defining an irregular polyhedron.

  5. Optical properties of dy doped lead and bismuth borate glasses - effect of glass composition, metal and semiconducting nanoparticles

    Science.gov (United States)

    Ooi, Hio Giap

    The optical properties of Dy3+ ions in lead borate and bismuth borate glasses are studied as a function of glass composition with PbO content (29.5 to 69.5mol%) and Bi2O3 content (29.5 to 59.5 mol%). We also studied the effect of metal and semiconducting nanoparticles on the absorption and fluorescence emission of Dy3+ ions in both lead and bismuth borate glasses. The absorption coefficient at each wavelength is obtained from the optical absorption spectrum of a glass sample, and the number density of rare-earth (RE) ions is calculated from the measurement of the glass density. These two parameters are then used to calculate the oscillator strength of each transition using Judd-Ofelt theory. Using the oscillator strength for each transition, we obtained the intensity parameters which represent changes in the symmetry of the ligand field at the Dy 3+ site (due to structural group changes and changes in Dy-O covalency). Radiative transition probabilities, the radiative lifetime of the excited states and the branching ratios are then obtained from these intensity parameters. The fluorescence spectra, obtained using 355 nm and 458 nm laser excitation, are analyzed by determining the area ratio of yellow/blue (Y/B) peaks and the wavelength of the hypersensitive transition (HST). The compositional dependence and effect of nanoparticles on the stimulated emission cross-section (sigmap), are then evaluated using radiative transition probability, the refractive index of the host glass, effective fluorescence linewidth, and the position of the band. In all of the glass systems, it was found that the optical properties are strongly influenced by structural changes arising from compositional variation and size of nanoparticles. Dy 3+ transitions exhibit large sigmap suggesting the possible utilization of these materials in laser applications.

  6. Optical properties of Mg2+, Yb3+, and Ho3+ tri-doped LiNbO3 crystals

    Science.gov (United States)

    Dai, Li; Liu, Chun-Rui; Tan, Chao; Yan, Zhe-Hua; Xu, Yu-Heng

    2017-04-01

    A series of LiNbO3 crystals tri-doped with Mg{}2+, Yb{}3+, and Ho{}3+ are grown by the conventional Czochraski technique. The concentrations of Mg{}2+, Yb{}3+, and Ho{}3+ ions in Mg:Yb:Ho:LiNbO3 crystals are measured by using an inductively coupled plasma atomic emission spectrometry. The x-ray diffraction is proposed to determine the lattice constant and analyze the internal structure of the crystal. The light-induced scattering of Mg:Yb:Ho:LiNbO3 crystal is quantitatively described via the threshold effect of incident exposure energy flux. The exposure energy ({E}{{r}}) is calculated to discuss the optical damage resistance ability. The exposure energy of Mg(7 mol):Yb:Ho:LiNbO3 crystal is 709.17 J/cm2, approximately 425 times higher than that of the Mg(1 mol):Yb:Ho:LiNbO3 crystal in magnitude. The blue, red, and very intense green bands of Mg:Yb:Ho:LiNbO3 crystal are observed under the 980-nm laser excitation to evaluate the up-conversion emission properties. The dependence of the emission intensity on pumping power indicates that the up-conversion emission is a two-photon process. The up-conversion emission mechanism is discussed in detail. This study indicates that Mg:Yb:Ho:LiNbO3 crystal can be applied to the fabrication of new multifunctional photoluminescence devices. Project supported by the National Natural Science Foundation of China (Grant No. 51301055), the Youth Science Fund of Heilongjiang Province, China (Grant No. QC2015061), the Special Funds of Harbin Innovation Talents in Science and Technology Research, China (Grant No. 2015RQQXJ045 ), and the Science Funds for the Young Innovative Talents of Harbin University of Science and Technology, China (Grant No. 201501).

  7. XPS Studies of Yb14MnSb11 and Yb14ZnSb11

    Energy Technology Data Exchange (ETDEWEB)

    Holm, A P; Ozawa, T C; Kauzlarich, S M; Morton, S A; Waddill, G D; Pickett, W E; Tobin, J G

    2003-10-02

    Measurements of core and valence electronic states of single crystals of the rare earth transition metal Zintl phases Yb{sub 14}MnSb{sub 11} and Yb{sub 14}ZnSb{sub 11} were performed using the X-ray photoelectron spectroscopy station of Beamline 7 at the Advanced Light Source. Sample surfaces of Yb{sub 14}MnSb{sub 11} and Yb{sub 14}ZnSb{sub 11} were measured as received, after Ar{sup +} ion bombardment, and after cleaving in situ. Detailed analysis of the clean Mn and Zn analog sample surfaces reveal a significant contribution of both Yb{sup 3+} and Yb{sup 2+} 4f states in the valence band region for the Zn analog and no contribution of Yb{sup 3+} states to the valence band for the Mn analog. This result is predicted for the Zn analog by Zintl counting rules, and single crystal X-ray diffraction studies presented here also support the mixed valency of Yb for Yb{sub 14}ZnSb{sub 11}. Further detailed analysis of the core and valence band structure of both Yb{sub 14}MnSb{sub 11} and Yb{sub 14}ZnSb{sub 11} will be presented.

  8. Local symmetry lowering in the cubic intermetallics YbPdBi and YbNiSb

    Energy Technology Data Exchange (ETDEWEB)

    LeBras, G.; Bonville, P.; Hodges, J.A.; Hammann, J.; Besnus, M.J.; Schmerber, G.; Dhar, S.K.; Aliev, F.G.; Andre, G. [DRECAM/SPEC, CE Saclay, Gif-sur-Yvette (France)

    1995-07-10

    A microscopic investigation of the cubic ternary alloys YbPdBi and YbNiSb, using {sup 170}Yb Mossbauer spectroscopy, reveals that the point symmetry at the site of the Yb{sup 3+} is far from cubic in both compounds. An analysis of the thermal variation of the quadrupolar 4f moment shows that the energy of the first crystal electric field transition is close to 20 K in YbPdBi and to 10 K in YbNiSb. Specific heat measurements are also presented in YbPdBi, and magnetic ordering is detected below 1 K in YbPdBi, with saturated Yb{sup 3+} moments of 1.25 {mu}{sub B}, and below 0.85 K in YbNiSb, with saturated moments of 1 {mu}{sub B}. A tentative explanation of the Yb site symmetry breaking is made in terms of a Jahn-Teller distortion within the {gamma}{sub 8} cubic quartet. (author)

  9. Photoelectron spectroscopy of strongly correlated Yb compounds

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, J.J.; Andrews, A.B.; Arko, A.J.; Bartlett, R.J.; Blythe, R.I. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Olson, C.G.; Benning, P.J.; Canfield, P.C. [Ames Laboratory, U. S. Department of Energy, Ames, Iowa 50011 (United States); Poirier, D.M. [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    1996-12-01

    The electronic properties of the Yb compounds YBCu{sub 2}Si{sub 2}, YBAgCu{sub 4}, and YbAl{sub 3} along with purely divalent Yb metal, have been investigated by means of high-resolution ultraviolet and x-ray photoelectron spectroscopy. We present the intrinsic characteristic features of the 4{ital f} levels of Yb while accounting for lattice vibrations and the manifestation of corelike energy levels degenerate with the valence states and modified by the temperature-dependent Fermi function. For these strongly correlated Yb-based compounds, the hole occupancy values ({ital n}{sub {ital f}}{approximately}0.6) directly obtained from integration of the divalent and trivalent portions of the 4{ital f} photoemission features indicate that these compounds are strongly mixed valent. The small intensity modulation with temperature in the divalent Yb 4{ital f} levels (0{endash}10{percent} over a {ital T}=20{minus}300 K range) is discussed within the conventional framework of the photoemission process and nominal allowances for lattice variations with temperature. Results from photoemission experiments on the divalent 4{ital f} levels of strongly correlated Yb compounds are remarkably similar to the 4{ital f} levels of purely divalent Yb metal. {copyright} {ital 1996 The American Physical Society.}

  10. Scintillation properties of YAG:Yb crystals

    CERN Document Server

    Antonini, P; Carugno, Giovanni; Iannuzzi, D

    2001-01-01

    We report on measurements of the light yield, emission spectrum, and time response of YAG:Yb crystals. The temperature dependence of light yield was investigated. Data show that YAG:Yb crystals are good scintillators, suitable for applications to neutrino detection and spectroscopy.

  11. Manipulation of Dy-Mn coupling and ferrielectric phase diagram of DyMn{sub 2}O{sub 5}: The effect of Y substitution of Dy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Z. Y.; Wang, Y. L.; Lin, L.; Liu, M. F.; Li, X.; Yan, Z. B.; Liu, J.-M. [Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-11-07

    DyMn{sub 2}O{sub 5} is an extraordinary example in the family of multiferroic manganites and it accommodates both the 4f and 3d magnetic ions with strong Dy-Mn (4f-3d) coupling. The electric polarization origin is believed to arise not only from the Mn spin interactions but also from the Dy-Mn coupling. Starting from proposed scenario on ferrielectricity in DyMn{sub 2}O{sub 5} where the exchange-strictions associated with the Mn{sup 3+}-Mn{sup 4+}-Mn{sup 3+} blocks and Dy{sup 3+}-Mn{sup 4+}-Dy{sup 3+} blocks generate the two ferroelectric sublattices, we perform a set of characterizations on the structure, magnetism, and electric polarization of Dy{sub 1-x}Y{sub x}Mn{sub 2}O{sub 5} in order to investigate the roles of Dy-Mn coupling in manipulating the ferrielectricity. It is revealed that the non-magnetic Y substitution of Dy suppresses gradually the Dy{sup 3+} spin ordering and the Dy-Mn coupling. Consequently, the ferroelectric sublattice generated by the exchange striction associated with the Dy{sup 3+}-Mn{sup 4+}-Dy{sup 3+} blocks is destabilized, but the ferroelectric sublattice generated by the exchange striction associated with the Mn{sup 3+}-Mn{sup 4+}-Mn{sup 3+} blocks remains less perturbed, enabling the ferrielectricity-ferroelectricity transitions with the Y substitution. A phenomenological ferrielectric domain model is suggested to explain the polarization reversal induced by the Y substitution. The present work presents a possible scenario of the multiferroic mechanism in not only DyMn{sub 2}O{sub 5} but probably also other RMn{sub 2}O{sub 5} members with strong 4f-3d coupling.

  12. Exploring the biocatalytic potential of a DyP-type peroxidase by profiling the substrate acceptance of Thermobifida fusca DyP peroxidase

    NARCIS (Netherlands)

    Loncar, Nikola; Colpa, Dana I.; Fraaije, Marco W.

    2016-01-01

    Dye-decolorizing peroxidases (DyPs) represent a new class of oxidative enzymes for which the natural substrates are largely unknown. To explore the biocatalytic potential of a DyP, we have studied the substrate acceptance profile of a robust DyP peroxidase, a DyP from Thermobifida fusca (TfuDyP). Wh

  13. Synthesis and photoluminescent characteristics of Dy3+ doped Gd2O3 phosphors

    Science.gov (United States)

    Jeena, T. R.; Ezhil Raj, A. Moses; Bououdina, M.

    2017-02-01

    Pure and dysprosium doped gadolinium oxide nanoparticles for three different concentrations (2, 5 and 10 mol.%) were synthesized by auto-combustion method using citric acid as fuel. The nanoparticles obtained were characterized using powder x-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), UV–vis–NIR spectroscopy and photoluminescence (PL) spectroscopy techniques. XRD pattern revealed the crystalline cubic phase with space group Ia3 (Space Group: 206) for both the pure and doped Gd2O3 nanoparticles. The metal oxide phase formation and purity of Gd2O3 nanoparticles were further confirmed from the FTIR spectra. Morphology of the pure Gd2O3 powder is loosely dispersed clusters of tiny particles with microscopic pores, whereas for the doped samples aggregates were broken to form small clusters. Optical absorption measurements were recorded in the UV–vis–NIR wavelength region and the optical band gap variations with dopant concentration were discussed. The PL spectra of pure and Dy3+ doped Gd2O3 nanoparticles have been studied and the effect of emitted light on the yellow-to-blue intensity ratio (Y/B) of Dy3+ emission was demonstrated.

  14. Hvem er vi? Hvem er de?

    DEFF Research Database (Denmark)

    Kryger, Niels

    2016-01-01

    Kommentaren tager afsæt i initiativer i de pædagogiske faglige foreninger i Europa EERA) og i Norden (NERA) og argumenterer for at det er forpligtelse for os som nordiske og europæiske pædagogiske forskere at gå op imod de stadigt mere ekskluderende vi-konstruktioner, som er blevet formuleret i f...

  15. Chemical co-precipitation synthesis and photoluminescence of LnP {sub x}V{sub 1-x}O{sub 4}:Dy{sup 3+} (Ln = Gd, La) derived from assembling hybrid precursors

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Bing [Department of Chemistry, Tongji University, Shanghai 200092 (China)]. E-mail: byan@tongji.edu.cn; Su, Xue-Qing [Department of Chemistry, Tongji University, Shanghai 200092 (China)

    2007-04-04

    A novel synthesis technology was applied to obtain GdP {sub x}V{sub 1-x}O{sub 4}:Dy{sup 3+} (x = 0.2, 0.3, 0.4, 0.5, 0.6, 0.7) and LaP {sub x}V{sub 1-x}O{sub 4}:Dy{sup 3+} (x = 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8) phosphors for the first time. And the doping concentration of Dy{sup 3+} ions was 3 mol.% in the two systems. Besides this, GdVO{sub 4} and LaVO{sub 4} doped with different concentration of Dy{sup 3+} ions were also synthesized. The rare earth coordination polymers with salicylic acid were used as precursors and the polyethylene glycol (PEG) was used as dispersing media. By an in situ co-precipitation process, we obtained the hybrid precursors. Both XRD and SEM indicated that the particles present good crystalline state, whose crystalline grain sizes were in the range of around 0.5-1 {mu}m. The optical properties of all the powder presented that the characteristic transitions of Dy{sup 3+} due to {sup 4}F{sub 9/2} {sup {yields}} {sup 6}H{sub 15/2} (blue) and {sup 4}F{sub 9/2} {sup {yields}} {sup 6}H{sub 13/2} (yellow) were detected. Besides this, in the system of GdP {sub x}V{sub 1-x}O{sub 4}:Dy{sup 3+}, the yellow-to-blue intensity ration (Y/B) depended on the value of P/V greatly, with the increasing of x value, the Y/B decreasing.

  16. Near infrared emission of TbAG:Ce3+,Yb3+ phosphor for solar cell applications

    Science.gov (United States)

    Meshram, N. D.; Yadav, P. J.; Pathak, A. A.; Joshi, C. P.; Moharil, S. V.

    2016-05-01

    Luminescent materials doped with rare earth ions are used for many devices such as optical amplifiers in telecommunication, phosphors for white light emitting diodes (LEDs), displays, and so on. Recently, they also have attracted a great interest for photovoltaic applications to improve solar cell efficiency by modifying solar spectrum. Crystal silicon (c-Si) solar cells most effectively convert photons of energy close to the semiconductor band gap. The mis-match between the incident solar spectrum and the spectral response of solar cells is one of the main reasons to limit the cell efficiency. The efficiency limit of the c-Si has been estimated to be 29% by Shockley and Queisser. However, this limit is estimated to be improved up to 38.4% by modifying the solar spectrum by a quantum cutting (down converting) phosphor which converts one photon of high energy into two photons of lower energy. The phenomenon such as the quantum cutting or the down conversion of rare earth ions have been investigated since Dexter reported the possibility of a luminescent quantum yield greater than unity in 1957. In the past, the quantum cutting from a vacuum ultraviolet photon to visible photons for Pr3+, Gd3+,Gd3+-Eu3+, and Er3+-Tb3+ had been studied. Recently, a new quantum cutting phenomenon from visible photon shorter than 500 nm to two infrared photons for Tb3+-Yb3+, Pr3+-Yb3+, and Tm3+-Yb3+ has been reported. The Yb3+ ion is suitable as an acceptor and emitter because luminescent quantum efficiency of Yb3+ is close to 100% and the energy of the only excited level of Yb3+ (1.2 eV) is roughly in accordance with the band gap of Si (1.1 eV). In addition, the Ce3+-doped Tb3Al5O12 (TbAG), used as a phosphor for white LED, has broad absorption bands in the range of 300-500 nm due to strong ligand field and high luminescent quantum efficiency. Therefore, the Ce3+ ions in the TbAG can be suitable as an excellent sensitizing donor for down conversion materials of Si solar cells. In this

  17. Politik er ikke lykken

    DEFF Research Database (Denmark)

    Steenbuch, Johannes Aakjær

    2011-01-01

    Der er ikke længere nogen højere sandhed i livet end den, flertallet bestemmer sig for – og dermed ingen del af livet, der ikke er politisk. Højre- og venstrefløjen er i bund og grund enige - enige om, at det er politikernes opgave at forære os det gode liv. Dermed bliver demokratiet totalitært. ...

  18. Ideologi er noget bras

    DEFF Research Database (Denmark)

    Hansen, Brian Benjamin; Bjerre, Henrik Jøker

    medieområdet kan dette skifte betragtes som den endelige sejr for den post-ideologiske konsensus, der går ud fra, at der ikke mere er behov for politisk diskussion, og at vi aldrig mere skal indlade os på farlige politiske eksperimenter. Ideologi er noget bras, sagde jo allerede Poul Schlüter. Med inspiration......, ideologiske ramme for vore liv. Ideologi er noget bras, men bras er også ideologi....

  19. Crystal structure of Tb5Ni2In4, and magnetic properties of Dy5Ni2In4

    Energy Technology Data Exchange (ETDEWEB)

    Provino, A.; Mudryk, Y.; Paudyal, D.; Smetana, V.; Manfrinetti, P.; Pecharsky, V.K.; Gschneidner Jr, Karl; Corbett, J.D.

    2012-02-27

    The crystal structure of the R5Ni2In4 intermetallic compounds was earlier reported for R Ho, Er, Tm, and Lu (Lu5Ni2In4-type, oP22, Pbam); more recently the isostructural phases Dy5Ni2In4 and Sc5Ni2In4 have also been identified. Three inequivalent crystallographic sites are occupied by the R atoms in these compounds. We have synthesized and characterized Dy5Ni2In4 and the two new isotypic compounds Tb5Ni2In4 and Y5Ni2In4. So far, none of the physical properties have been reported on any of these phases; in this article we report on the physical properties of the Dy5Ni2In4 and the crystal structure of Tb5Ni2In4 and Y5Ni2In4 compounds. Measurements of the magnetic properties performed on Dy5Ni2In4 show a ferromagnetic-like ordering with a T-C approximate to 105 K, followed by multiple magnetic orderings at lower temperatures. The fit of the inverse susceptibility in the paramagnetic state follows the Curie-Weiss law, where mu(eff). - 10.3 mu(B)/Dy-atom (close to theoretical value of 10.64 mu(B) for the free ion Dy3+) and a positive paramagnetic Curie temperature theta(p) - 58 K. Ni atoms are most likely to be nonmagnetic. The heat capacity also shows three peaks: a large one at 103K and two weaker at 12 and 8 K, respectively; the in-field heat capacity data corroborate these results, suggesting ferromagnetic and antiferromagnetic orderings at the temperature of 103 and 12 K, respectively. Low temperature x-ray diffraction has shown that the compound does not undergo any structural change down to 5K. (C) 2012 American Institute of Physics.

  20. Forbrugernes veje er mangfoldige

    DEFF Research Database (Denmark)

    Stacey, Julia; Nielsen, Niels Asger

    2005-01-01

    Fremtidens forbrugere vil have sunde fødevarer, der smager godt. Det lyder umiddelbart som et krav, der skulle være til at opfylde, men så enkelt er det nu ikke. De fødevarer, der smager godt, er ikke altid sunde, og en forbruger er ikke bare en forbruger. Nogle vil udfordres og overraskes. Andre...

  1. Fattigdom er blevet hverdag

    DEFF Research Database (Denmark)

    Andrade, Stefan Bastholm; Ditlevsen, Kia

    2014-01-01

    Det er sæson for julehjælp til fattige familier og donationer til hjemløse. Problemerne er ikke sæsonafhængige, men resten af året er indignationen sværere at spore. Fattigdom opfattes nemlig i stigende grad som et permanent individuelt vilkår og ikke som udtryk for samfundskrise...

  2. Hvad er talesprog?

    DEFF Research Database (Denmark)

    Steensig, Jakob

    2009-01-01

    Hvad er talesprog lingvistisk set? Hvad er kendetegnende for det i forhold til skriftsproget, og hvordan kan man arbejde med at udvikle en forståelse og værdsættelse af talesproget hos eleverne? Vores traditionelle sprogvidenskabelige beskrivelses¬apparat er udviklet til at beskrive skriftsproget...

  3. Activation of Small Molecules by DyI_2 and Dy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results The reactivities of dysprosium diiodide and metallic dysprosium toward small molecules are discussed.For instance,DyI2-induced silyl radical reactions are described.The combination of dysprosium diiodide and dichloromethane can serve as an effective methylene transfer reagent for cyclopropanation of unfunctionalized alkenes beyond that possible with other metal-dichloromethane systems.Furthermore,we report that the combination of chlorosilane and metallic Dy can also serve as an effective prom...

  4. Time-dependent relativistic density functional study of Yb and YbO

    Institute of Scientific and Technical Information of China (English)

    XU WenHua; ZHANG Yong; LIU WenJian

    2009-01-01

    The low-lying electronic states of Yb and YbO are investigated by using time-dependent relativistic density functional theory,which is based on the newly developed exact two-component Hamiltonian resulting from symmetrized elimination of the small component.The nature of the excited states is analyzed by using the full molecular symmetry.The calculated results support the previous experimental assignment of the ground and excited states of YbO.

  5. DySectAPI: Scalable Prescriptive Debugging

    DEFF Research Database (Denmark)

    Jensen, Nicklas Bo; Karlsson, Sven; Quarfot Nielsen, Niklas;

    We present the DySectAPI, a tool that allow users to construct probe trees for automatic, event-driven debugging at scale. The traditional, interactive debugging model, whereby users manually step through and inspect their application, does not scale well even for current supercomputers. While...

  6. LiYbCl4(THF4

    Directory of Open Access Journals (Sweden)

    Lukas Richtera

    2011-06-01

    Full Text Available The title compound, di-μ-chlorido-dichlorido-1κ2Cl-tetrakis(tetrahydrofuran-1κ2O,2κ2O-lithiumytterbium(III, [LiYbCl4(C4H8O4], was prepared by the reaction of YbCl3(THF3 with LiCl in THF (THF is tetrahydrofuran. The central motif of the structure is a Yb(μ-Cl2Li ring. The Yb atom is hexacoordinated to four Cl atoms and two THF molecules oriented in a trans fashion. The Li atom has a tetrahedral environment and is coordinated to two Cl atoms and two THF molecules. No intermolecular interactions other than van der Waals forces were observed. Two of the THF molecules are disordered over two positions.

  7. Properties of Yb:YAG scintillators

    CERN Document Server

    Antonini, P; Bressi, G; Carugno, Giovanni; Santilli, P

    2002-01-01

    Relative light yield (LY) dependence on temperature for Yb:YAG crystals containing from 10% to 100% of Yb dopant is studied for gamma and alpha excitations. The maximum LY is achieved at 120 KYb 25%)YAG. Linearity of the light output is checked. alpha/gamma ratio is found to be 0.42+-0.02. Pulse shapes induced by gamma and alpha particles and cosmic rays are investigated by analyzing a set of single events recorded. Gamma events are fast tau<4 ns), while other kinds of radiation give rise to more complicated and longer profiles, allowing particle discrimination. Dependence of scintillation properties on concentration of Yb and purity is discussed.

  8. Nuclear structure studies in the area around the valence maximum of {sup 170}Dy with CLARA+PRISMA

    Energy Technology Data Exchange (ETDEWEB)

    Soederstroem, Paer-Anders [Uppsala University (Sweden)

    2009-07-01

    While the existence of shell closures and the search for exotic doubly magic nuclei is a cornerstone of our understanding of the atomic nucleus, their even-even, doubly-mid-shell counterparts are arguably even more rare. Above the sd shell, the corresponding doubly mid-shell, even-even systems which are particle bound are limited to {sup 28}Si, {sup 38}Si, {sup 48}Cr and {sup 170}Dy. Assuming the standard spherical shell gaps, {sup 170}Dy might naively be expected to be amongst the most collective of all nuclei. The double mid-shell at {sup 170}Dy may also represent the single best hope in the entire Segre chart for the empirical realization of the SU(3) dynamical symmetry of the interacting boson model. An experiment for nuclear structure studies of {sup 170}Dy and its neighbors has been performed at Laboratori Nazionali di Legnaro. Multi-nucleon transfer reactions with a {sup 82}Se beam on a {sup 170}Er target were used to reach the neutron-rich isotopes. The reaction fragments were identified using the magnetic spectrometer PRISMA and the {gamma}-ray spectra were recorded using the CLARA germanium detector array. The analysis of this data is ongoing. Preliminary {gamma}-ray spectra for neutron rich isotopes in this area are presented as well as relative cross sections for production of these isotopes in multi-nucleon transfer reactions.

  9. Spectroscopy of Neutron-Rich $^{168,170}$Dy: Yrast Band Evolution Close to the $N_{p}N_{n}$ Valence Maximum

    CERN Document Server

    Söderström, P A; Regan, P H; Algora, A; de Angelis, G; Ashley, S F; Aydin, S; Bazzacco, D; Casperson, R J; Catford, W N; Cederkäll, J; Chapman, R; Corradi, L; Fahlander, C; Farnea, E; Fioretto, E; Freeman, S J; Gadea, A; Gelletly, W; Gottardo, A; Grodner, E; He, C Y; Jones, G A; Keyes, K; Labiche, M; Liang, X; Liu, Z; Lunardi, S; Muarginean, N; Mason, P; Menegazzo, R; Mengoni, D; Montagnoli, G; Napoli, D; Ollier, J; Pietri, S; Podolyák, Z; Pollarolo, G; Recchia, F; Şahin, E; Scarlassara, F; Silvestri, R; Smith, J F; Spohr, K M; Steer, S J; Stefanini, A M; Szilner, S; Thompson, N J; Tveten, G M; Ur, C A; Valiente-Dobón, J J; Werner, V; Williams, S J; Xu, F R; Zhu, J Y

    2010-01-01

    The yrast sequence of the neutron-rich dysprosium isotope Dy-168 has been studied using multi-nucleon transfer reactions following the collision of a 460-MeV Se-82 beam and a Er-170 target. The reaction products were identified using the PRISMA magnetic spectrometer and the gamma rays detected using the CLARA HPGe-detector array. The 2+ and 4+ members of the previously measured ground state rotational band of Dy-168 was confirmed and the yrast band extended up to 10+. A tentative candidate for the 4+ to 2+ transition in Dy-170 was also identified. The data on this and lighter even-even dysprosium isotopes are interpreted in terms of Total Routhian Surface calculations and the evolution of collectivity approaching the proton-neutron valence product maximum is discussed.

  10. Crystal structure and Mössbauer studies of the isotypic Fe6-cluster compounds RE15[Fe8C25], RE=Dy, Ho

    KAUST Repository

    Davaasuren, Bambar

    2015-05-01

    The carboferrates RE15[Fe8C25] (RE=Dy, Ho) were prepared from mixtures of the elements by arc-melting followed with subsequent annealing at 1373 K. The crystal structures were determined from single crystal X-ray diffraction data and revealed an isotypic relationship to Er15[Fe8C25] (hP48, P321). The main feature of the crystal structure is given by Fe6 cluster units characterized by covalent Fe-Fe bonding interactions. 57Fe Mössbauer spectra of Dy15[Fe8C25] were fitted by three subspectra with relative spectral weights of about 3:3:2 which is in general agreement with the crystal structure. Below 50 K, an onset of magnetic hyperfine fields at the three iron sites is observed which is supposed to be caused by dipolar fields arising from neighboring, slowly relaxing Dy magnetic moments.

  11. Optical spectra of Dy3+-doped GdVO4 and Ca3Sc2Ge3O12 crystals and evaluation of the Ω2/Ω6 ratio as a quality factor for the classification of Dy3+-activated crystalline hosts

    Science.gov (United States)

    Cavalli, Enrico

    2016-11-01

    The room temperature absorption spectra of Dy3+-doped GdVO4 and Ca3Sc2Ge3O12 crystals have been measured and analysed in the framework of the Judd-Ofelt Theory. The calculated intensity parameters have then been correlated with the intensities of the emission bands in the yellow and blue region. The analysis has then been extended to a number of host lattices using literature data, and a general empirical model has been proposed, correlating the Ω2/Ω6 and the yellow to blue (Y/B) ratio in order to define a criterion for predicting the visible luminescence properties of the Dy-activated crystalline materials.

  12. Thermochromism and fluorescence in dyed PEO films

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, Archana; S, Raghu; V, Mini; C, Sharanappa; H, Devendrappa, E-mail: dehu2010@gmail.com [Dept. of Physics, Mangalore University, Managalagangothri, Mangalore--574199 (India)

    2015-06-24

    The optical absorbance spectra of solution casted pure & methyl blue (MB) dyed polyethylene oxide (PEO) films were recorded in a wavelength range from 190-1100nm at different temperatures. The absorbance was found to increases with increasing temperature. Fluorescence micrographs confirmed the interaction between polymer and dye and also revealed decreased crystallinity of the sample. Fluorescence quantum yield has been calculated with the help of fluorescence spectra.

  13. Structural studies and c dependence in La2-DyCaBa2Cu4+O type mixed oxide superconductors

    Indian Academy of Sciences (India)

    S Rayaprol; Krushna Mavani; C M Thaker; D S Rana; Keka Chakravorty; S K Paranjape; M Ramanadham; Nilesh A Kulkarni; D G Kuberkar

    2002-05-01

    A new series of mixed oxide superconductors with the stoichiometric composition La2-DyCaBa2Cu4+O ( = 0.0 - 0.5, = 2) has been studied for structural and superconductiong properties. Our earlier studies on La2-(Y/Er)CaBa2Cu4+O series, show a strong dependence of c on hole concentration (sh). In the present work, the results of the analysis of the neutron diffraction measurements at room temprerature on = 0.3 and 0.5 samples are reported. It is interesting to know that Ca substitutes for both La and Ba site with concomitant displacement of La onto Ba site. Superconductivity studies show that maximum c is obtained for = 0.5, = 1.0 sample (c ∼ 75 K), for La1.5Dy0.5Ca1Ba2Cu5O (La-2125).

  14. 615 fs pulses with 17 mJ energy generated by an Yb:thin-disk amplifier at 3 kHz repetition rate.

    Science.gov (United States)

    Fischer, Jonathan; Heinrich, Alexander-Cornelius; Maier, Simon; Jungwirth, Julian; Brida, Daniele; Leitenstorfer, Alfred

    2016-01-15

    A combination of Er/Yb:fiber and Yb:thin-disk technology produces 615 fs pulses at 1030 nm with an average output power of 72 W. The regenerative amplifier allows variation of the repetition rate between 3 and 5 kHz with pulse energies from 13 to 17 mJ. A broadband and intense seed provided by the compact and versatile fiber front-end minimizes gain narrowing. The resulting sub-ps performance is ideal for nonlinear frequency conversion and pulse compression. Operating in the upper branch of a bifurcated pulse train, the system exhibits exceptional noise performance and stability.

  15. The melting diagram of the Ti-Dy-Si system in the Ti-Ti{sub 5}Si{sub 3}-Dy{sub 5}Si{sub 3}-Dy region

    Energy Technology Data Exchange (ETDEWEB)

    Fartushna, Yu. [Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhizhanovsky Street, 03142 Kiev (Ukraine)], E-mail: julia@ipms.kiev.ua; Meleshevich, K.; Samelyuk, A.; Bulanova, M. [Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhizhanovsky Street, 03142 Kiev (Ukraine)

    2009-04-03

    The phase equilibria in the Ti-Ti{sub 5}Si{sub 3}-Dy{sub 5}Si{sub 3}-Dy part of the Ti-Dy-Si system were studied by DTA, X-ray diffraction, metallography and EPMA. The melting diagram, isopleths at 5Si, 65Ti and 65Dy, and a reaction scheme were constructed. The solidus surface is characterized by the following three-phase fields: <{beta}-Ti> + + DySi>, <{beta}-Ti> + DySi> + <{alpha}-Dy>, DySi> + <{alpha}-Dy> + <Dy{sub 5}Si{sub 3}>, and + DySi> + <Dy{sub 5}Si{sub 3}>. The first two fields form via U-type equilibria, L + {r_reversible} <{beta}-Ti> + DySi> and L + <{beta}-Ti> {r_reversible} DySi> + <{alpha}-Dy>, at 1320 and 1170 deg. C, respectively. The third three-phase field results from an invariant eutectic four-phase equilibrium, L {r_reversible} DySi> + <{alpha}-Dy> + <Dy{sub 5}Si{sub 3}>, at 1157 {+-} 6 deg. C. The fourth one is the result of a P-type equilibrium, L + + <Dy{sub 5}Si{sub 3}> {r_reversible} DySi>. The temperature of the latter was estimated to be within the interval 1650-1700 deg. C.

  16. Fluxus-øer

    DEFF Research Database (Denmark)

    van der Meijden, Peter Alexander

    2008-01-01

    "Fluxus-øer" er en introduktion til Fluxus med udgangspunkt i den tyske galleri-ejer René Blocks samling, som udstillingen "Food for Thought" i Sukkerfabrikken i Stege (Møn) præsenterede et udvalg af. Artiklen beskriver Fluxus som et heterotopi som beskrevet af Michel Foucault i "Of Other Spaces"...

  17. Vreden er over os

    DEFF Research Database (Denmark)

    Mehlsen, Camilla

    2006-01-01

    Urolige elever, cyklister - der giver fuck-finger, aggressive demonstranter. Samtiden er på vej ind i en æra domineret af vrede, siger rektor Lars-Henrik Schmidt, der er aktuel med bogen 'Om vreden'. Udgivelsesdato: Juni...

  18. Tale er guld

    DEFF Research Database (Denmark)

    Juel Henrichsen, Peter

    2014-01-01

    Mange danske kommuner er parate til at indfase automatisk talegenkendelse, men er samtidig nervøse efter en lang række dårlige businesscases i den nærmere fortid. Der klages over høje licenspriser og lavt serviceniveau, den typiske virkning af et de facto monopol på leverandørsiden. Denne artikel...

  19. MIT HJEM ER HVOR MIT HJERTE ER

    DEFF Research Database (Denmark)

    Høst, Jeppe Engset

    2014-01-01

    Ideen om at arbejde med det man kalder de stedbundne ressourcer på en ny måde, er relevant på Bornholm hvor events som blandt andet festivalen ’Wonderfestiwall’, strandfesten ’Vang Pier Beach Party’, karnevallet ’Svaneke Beach Party, kokkekonkurrencen ’Sol over Gudhjem’ og filmfestivalen ’Bornsho...

  20. Optical study of Yb{sup 3+}/Yb{sup 2+} conversion in CaF{sub 2} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kaczmarek, Slawomir M [Institute of Physics, Szczecin University of Technology, Aleja Piastow 48, 70-310 Szczecin (Poland); Tsuboi, Taiju [Faculty of Engineering, Kyoto Sangyo University, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan); Ito, Masahiko [Physical Chemistry of Luminescent Materials, Claude Bernard/Lyon 1 University, UMR CNRS 5620, Batiment A Kastler, 10 rue Ampere, 69622 Villeurbanne (France); Boulon, Georges [Physical Chemistry of Luminescent Materials, Claude Bernard/Lyon 1 University, UMR CNRS 5620, Batiment A Kastler, 10 rue Ampere, 69622 Villeurbanne (France); Leniec, Grzegorz [Institute of Physics, Szczecin University of Technology, Aleja Piastow 48, 70-310 Szczecin (Poland)

    2005-06-29

    Yb{sup 3+} ions with various site symmetries have been observed in the absorption and emission spectra of Yb{sup 3+}:CaF{sub 2} crystals, both {gamma}-irradiated and annealed in hydrogen. The absorption intensity value is found to be much higher for the {gamma}-irradiated crystal and strongly dependent on the gamma dose. The UV absorption spectra of {gamma}-irradiated and H{sub 2}-annealed CaF{sub 2}:5 at.% Yb{sup 3+} crystals are quite similar. Yb{sup 2+} absorption bands are observed at 360, 315, 271, 260, 227 and 214 nm, which are called A, B, C, D, F and G bands, respectively. For {gamma}-irradiated CaF{sub 2}:30 at.%