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Sample records for gd eu sm

  1. Separation and microdetermination of Sm, Eu and Gd from egyptian beach monazite using solvent extraction techniques

    International Nuclear Information System (INIS)

    Aly, M.M.; Baky, K.A.; Aly, H.F.

    1998-01-01

    Full text: The Lanthanide hydrous oxides concentrate produced from monazite mineral of the Egyptian beach black sand deposits contains a considerable percent of samarium, europium and gadolinium as a group, which in turn represents a valuable concentration with respect to their international prices due to their scarcity and wide demand in modern industries. The rare earth elements, being chemically similar to one another, invariably occur together in the source minerals and behaves as a single chemical entity. The problem of separating them one from another for scientific purposes or industrial use has been one of the most challenging tasks of rare earth technology. The present work is directed to microdetermination of Sm, Eu and Gd in their acid solutions after complete separation and recovery using di-2-ethyl hexyl phosphoric acid diluted with kerosene (D2EHPA/KX) as a solvent for the extraction processes. Different acid solutions with different pH values for their stripping were utilised

  2. Direct observation and analysis of nanoscale precipitates in (Sm,Eu,Gd) Ba.sub.2./sub.Cu.sub.3./sub.O.sub.y./sub

    Czech Academy of Sciences Publication Activity Database

    Muraldihar, M.; Sakai, N.; Jirsa, Miloš; Koshizuka, N.; Murakami, M.

    2004-01-01

    Roč. 85, č. 16 (2004), s. 3504-3506 ISSN 0003-6951 Institutional research plan: CEZ:AV0Z1010914 Keywords : nanoscale particles * secondary phase * melt-textured materials * (Sm,Eu,Gd)-123 * Gd-211 * TEM * (LRE, Zr)BaCuO Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.308, year: 2004

  3. Facile hydrothermal synthesis and luminescent properties of Sm3+/Eu3+ codoped GdPO4 phosphors

    Science.gov (United States)

    Yang, Junfeng; Xiong, Hailong; Dong, Jianchao; Yang, Chunming; Gan, Shucai; Zou, Lianchun

    2017-12-01

    Well-defined GdPO4 nanocrystals were successfully prepared through the facile hydrothermal synthesis route followed by a heat treatment. The microstructure, morphologies and photoluminescence properties of as-prepared samples were investigated via X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectroscopy and luminescence decay, which were significantly affected by the reaction conditions (phosphorus source, acidity of hydrothermal process and surfactants). It is found that Sodium dodecyl sulfate (SDS) as a shape modifier has the dynamic effect by adjusting the growth rate of different facets, resulting in morphology transformation of GdPO4·H2O from the nanowire (without SDS) to the nanorod (with SDS). Strong yellow-orange emissions could be obtained in Sm3+ and Eu3+ ions codoped GdPO4 phosphors under ultraviolet light irradiation. Moreover, the energy transfer mechanism from Sm3+ to Eu3+ has been studied and proved to be a dipole-dipole interaction mechanism. These results show this yellow-orange-emitting phosphors material may have potential applications in field-emission displays.

  4. Determination of Gd, Sm, Eu and Dy in uranium compounds by atomic absorption spectrophotometry using a graphite furnace

    International Nuclear Information System (INIS)

    Modenesi, C.R.; Abrao, A.

    1984-01-01

    The separation of Gd, Sm, Eu and Dy from uranium and its determination by graphite furnace atomic absorption spectrophotometry is outlined. The lanthanides were separated by means of the percolation of the uranyl nitrate solution 0,3 M in HF (50-250g of U 3 O 8 perliter) through an Al 2 O 3 column. The lanthanides retained in the column were eluted with 1M HCl. As thorium is also retained into the column under these conditions, its interference was studied. The determination limits of the method range from 0,01 to 0,1 μg of lanthanide per gram of uranium. (Author) [pt

  5. White-emission in single-phase Ba2Gd2Si4O13:Ce3 +,Eu2 +,Sm3 + phosphor for white-LEDs

    Science.gov (United States)

    Jiang, Xiumin; Zhang, Yuqian; Zhang, Jia

    2018-03-01

    To develop new white-light-emitting phosphor, a series of Ce3 +-Eu2 +-Sm3 + doped Ba2Gd2Si4O13 (BGS) phosphors were prepared by the solid-state reaction method, and their photoluminescence properties were studied. The Ce3 + and Eu2 + single-doped BGS show broad emission bands around in the region of 350-550 and 420-650 nm, respectively. By co-doping Ce3 +-Eu2 + into BGS, the energy transfer (ET) from Ce3 + to Eu2 + is inefficient, which could be due to the competitive absorption between the two activator ions. The Sm3 +-activated BGS exhibits an orangey-red emission in the region of 550-750 nm. To achieve white emission, the BGS:0.06Ce3 +,0.04Eu2 +,ySm3 + (0 ≤ y ≤ 0.18) phosphors were designed, in which the ET from Ce3 +/Eu2 + to Sm3 + was observed. The emission color can be tuned by controlling the Sm3 + concentration, and white emission was obtained in the BGS:0.06Ce3 +,0.04Eu2 +,0.06Sm3 + sample. The investigation of thermal luminescence stability for the typical BGS:0.06Ce3 +,0.04Eu2 +,0.06Sm3 + sample reveals that the emission intensities of both Eu2 + and Sm3 + demonstrate continuous decrease but the Ce3 + emission is enhanced gradually with increasing temperature. The corresponding reason has been discussed.

  6. New K isomers in the neutron-rich N =100 isotones 162Sm, 163Eu, and 164Gd

    Science.gov (United States)

    Yokoyama, R.; Go, S.; Kameda, D.; Kubo, T.; Inabe, N.; Fukuda, N.; Takeda, H.; Suzuki, H.; Yoshida, K.; Kusaka, K.; Tanaka, K.; Yanagisawa, Y.; Ohtake, M.; Sato, H.; Shimizu, Y.; Baba, H.; Kurokawa, M.; Nishimura, D.; Ohnishi, T.; Iwasa, N.; Chiba, A.; Yamada, T.; Ideguchi, E.; Fujii, T.; Nishibata, H.; Ieki, K.; Murai, D.; Momota, S.; Sato, Y.; Hwang, J. W.; Kim, S.; Tarasov, O. B.; Morrissey, D. J.; Sherrill, B. M.; Simpson, G.; Praharaj, C. R.

    2017-03-01

    Very neutron-rich Z ˜60 isotopes produced by in-flight fission of a 345 MeV/nucleon 238U beam at the RI Beam Factory, RIKEN Nishina Center, have been studied by delayed γ -ray spectroscopy. New isomers were discovered in the neutron-rich N =100 isotones 162Sm, 163Eu, and 164Gd. Half-lives, γ -ray energies, and relative intensities of these isomers were obtained. Level schemes were proposed for these nuclei and the first 2+ and 4+ states were assigned for the even-even nuclei. The first 2+ and 4+ state energies decrease as the proton numbers get smaller. The energies and the half-lives of the new isomers are very similar to those of 4- isomers known in less neutron-rich N =100 isotones 168Er and 170Yb. A deformed Hartree-Fock with angular momentum projection model suggests Kπ=4- two-quasiparticle states with ν 7 /2 [633 ]⊗ν 1 /2 [521 ] configurations with similar excitation energy. The results suggest that neutron-rich N =100 nuclei are well deformed and the deformation gets larger as Z decreases to 62. The onset of K isomers with the same configuration at almost the same energy in N =100 isotones indicates that the neutron single-particle structures of neutron-rich isotones down to Z =62 do not change significantly from those of the Z =70 stable nuclei. Systematics of the excitation energies of new isomers can be explained without the predicted N =100 shell gap.

  7. Positron annihilation studies in high-Tc superconductors RBa2Cu3Oy, R: La, Nd, Sm, Eu, Gd, Dy, Ho, Y, Er

    International Nuclear Information System (INIS)

    Lagouri, T.; Dedoussis, S.; Chardalas, M.; Liolios, A.

    1997-01-01

    Positron lifetime and Doppler broadening of the annihilation line measurements have been performed at room temperature in high-T c superconductors RBa 2 Cu 3 O y , where R: La, Nd, Sm, Eu, Gd, Dy, Ho, Y, Er and 6.9 c superconducting samples RBa 2 Cu 3 O y , where R: Nd, Sm, Eu, Ho, Y, Er as a function of temperature between 14 K and 293 K. It was observed that the positron lifetime and the S parameter values at room temperature have no obvious trend in their variation from the yttrium substitution by a rare-earth element. It was also observed that the temperature dependence of the positron annihilation parameters is similar in the high-T c superconducting samples. (orig.)

  8. Synthesis and magnetism of μ-oxamido-bridged Cu2IILnIII - type heterotrinuclear complexes (Ln = Ce, Nd, Sm, Eu, Gd, Tb, Dy, Er)

    International Nuclear Information System (INIS)

    Li, Y.T.; Yan, C.W.

    2001-01-01

    Eight new Cu 2 II Ln III - type (Ln = Ce, Nd, Sm, Eu, Gd, Tb, Dy, Er) heterotrinuclear complexes bridged by N,N'-bis (2-aminopropyl)oxamidocopper(II) [Cu(oxdn)], namely Cu 2 (oxdn)Ln(NO 3 ) 3 , have been synthesized and characterized by elemental analyses, molar conductivity measurements and spectroscopic (IR, UV, ESR) studies. Magnetic susceptibility measurements (4.2 ∼300 K) and studies of Cu 2 (oxdn)Gd(NO 3 ) 3 complex have revealed that the central gadolinium(III) and terminal copper(II) ions are ferromagnetically coupled with the exchange integral J (Cu-Gd) = +2.98 cm -1 , while an antiferromagnetic coupling is detected between the terminal copper(II) metal ions with the exchange integral J' (Cu-Gd) = -0.75 cm -1 , on the basis of the spin Hamiltonian operator [H -2J(S Cu1 -S Gd +S Cu2 +S Gd )-2J'(S Cu1 S Cu2 )]. (author)

  9. Síntesis hidrotermal de monocristales LnMn2O5 (Ln= Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho y Er

    Directory of Open Access Journals (Sweden)

    Señarís Rodríguez, M. A.

    2008-08-01

    Full Text Available Ten single crystals of the series LnMn2O5 (Ln= Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er were synthesized by hydrothermal synthesis in a single step and without subsequent thermal treatments from aqueous solutions of metals salts at 240 ºC. The obtained single crystals have a size of various micrometers and their morphology changes throughout the serie: they are polygonal in the case of the compounds with Ln= Pr, Nd, Sm, Eu and Gd and needle-like in the case of the compounds with Ln= Y, Tb, Dy, Ho and Er. After the analysis of the obtained products employing different conditions of synthesis we attributed the different morphology to a greater growth rate along the c axis when the smaller ions (Y, Tb, Dy, Ho y Er are involved, due to their better adaptation to the compound’s crystal structure.Se han conseguido preparar monocristales de 10 óxidos mixtos de la serie LnMn2O5 (Ln= Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho y Er mediante síntesis hidrotermal optimizada, en un único paso y sin tratamientos térmicos posteriores partiendo de las correspondientes sales metálicas en disolución acuosa a 240 ºC. Los monocristales obtenidos son relativamente grandes, de varias micras y su morfología varía a lo largo de la serie: es poligonal en el caso de los compuestos de los lantánidos del inicio de la serie (Ln= Pr, Nd, Sm, Eu y Gd y acicular en el caso de los compuestos de Y y de los lantánidos del final de la serie (Ln= Tb, Dy, Ho y Er. Tras el análisis de los productos obtenidos empleando distintas condiciones de síntesis atribuimos la diferente morfología a una mayor velocidad de crecimiento cristalino a lo largo del eje c cuando intervienen los iones más pequeños (Y, Tb, Dy, Ho y Er debido a la mejor adaptación de éstos últimos a la estructura cristalina del compuesto.

  10. Luminescence characteristic of RE (RE = Pr, Sm, Eu, Tb, Dy) and energy levels of lanthanide ions in Gd5Si3O12N

    Science.gov (United States)

    Zhang, Zhi-Jun; Yang, Woochul

    2017-10-01

    Polycrystalline Gd5Si3O12N: RE (RE = Pr, Sm, Eu, Tb and Dy) phosphors have been synthesized via a solid-state reaction method at high temperature, and their photoluminescence properties were studied. The absorption peak at about 230 nm is attributed to the host absorption. For the Pr3+-doped sample, the typical excitation lines located at 273 nm originating from the 8S7/2 → 6IJ (J = 5/2, 7/2) transitions of the Gd3+ ions were observed in the excitation spectra. Upon excitation at 227 nm UV light, the 4f15d → 4f2 emission band (350-450 nm) and typical 4f2 → 4f2 emission lines (450-700 nm) assigned to Pr3+ were observed. The Sm3+-doped sample exhibits a bright red emission owing to the 4G5/2 → 6HJ (J = 5/2, 7/2 and 9/2) transitions. However, the charge transfer band of Sm3+ was not observed in the excitation spectrum. There is a broad band from 200 to 350 nm originating from the charge transfer transition (CT) of the Eu3+ (O2-/N3- → Eu3+) in the excitation spectra, and the strongest peak in the emission spectra located at 615 nm is due to the electric-dipole 5D0 → 7F2 transition of Eu3+. For the Tb3+-doped sample, it shows 5D3 →7FJ (J = 5, 4, 3, 2) blue line emissions and 5D4 → 7FJ (J = 6, 5, 4, 3) green line emissions under the excitation of Tb3+. The Dy3+-activated sample upon excitation at 349 and 386 nm UV light shows blue-green and orange-red emission lines originating from 4F9/2 → 6HJ (J = 15/2, 13/2) transitions. In addition, the energy transfer from the host lattice to the luminescence activators (i.e. Pr3+, Sm3+, Eu3+, Tb3+, Dy3+) has been confirmed. In addition, the energy level diagram including the 4f and 5d energy levels of all Ln2+ and Ln3+ ions relative to the valence and conduction band of Gd5Si3O12N were constructed and discussed.

  11. Synthesis under ambient pressure and tri-axial magnetic orientation in REBa2Cu4O8 (RE = Y, Sm, Eu, Gd, Dy, Ho, Er)

    International Nuclear Information System (INIS)

    Yamaki, M.; Horii, S.; Haruta, M.; Maeda, T.; Shimoyama, J.

    2011-01-01

    REBa 2 Cu 4 O 8 (RE124) was synthesized by a flux method in ambient pressure for RE = Y, Sm, Eu, Gd, Dy, Ho and Er. Tri-axial orientation of RE124 was achieved in a modulated rotating magnetic field of 10 T. Orientation axes in RE124 depended on the type of RE. Magnetization axes were determined from magnetic anisotropies of Cu and RE ions. We report the rare-earth (RE)-dependent magnetization axes of REBa 2 Cu 4 O 8 , which was synthesized by a flux method under ambient pressure, using powder samples tri-axially oriented in a modulated rotating magnetic field of 10 T. By optimizing the growth temperature and cooling rate, RE124 crystals were successfully grown for RE = Y, Sm, Eu, Gd, Dy, Ho, and Er. From the X-ray diffraction measurement, the magnetically oriented directions were largely dependent on the type of RE ions of RE124. However, the tri-axial magnetic anisotropies of RE124 could be qualitatively understood in terms of the magnitude relation between the single-ion magnetic anisotropy of RE 3+ ions and the magnetic anisotropy generated by the CuO 2 plane and Cu-O chain. For the practical use of this magneto-scientific process, the control of magnetization axes and tri-axial magnetic anisotropies through crystallochemical control is indispensable.

  12. Determination of Debye temperatures and Lamb–Mössbauer factors for LnFeO3 orthoferrite perovskites (Ln  =  La, Nd, Sm, Eu, Gd)

    Science.gov (United States)

    Scrimshire, A.; Lobera, A.; Bell, A. M. T.; Jones, A. H.; Sterianou, I.; Forder, S. D.; Bingham, P. A.

    2018-03-01

    Lanthanide orthoferrites have wide-ranging industrial uses including solar, catalytic and electronic applications. Here a series of lanthanide orthoferrite perovskites, LnFeO3 (Ln  =  La Nd; Sm; Eu; Gd), prepared through a standard stoichiometric wet ball milling route using oxide precursors, has been studied. Characterisation through x-ray diffraction and x-ray fluorescence confirmed the synthesis of phase-pure or near-pure LnFeO3 compounds. 57Fe Mössbauer spectroscopy was performed over a temperature range of 10 K–293 K to observe hyperfine structure and to enable calculation of the recoil-free fraction and Debye temperature (θ D) of each orthoferrite. Debye temperatures (Ln  =  La 474 K Nd 459 K Sm 457 K Eu 452 K Gd 473 K) and recoil-free fractions (Ln  =  La 0.827; Nd 0.817; Sm 0.816; Eu 0.812; Gd 0.826) were approximated through minimising the difference in the temperature dependent experimental centre shift and theoretical isomer shift, by allowing the Debye temperature and isomer shift values to vary. This method of minimising the difference between theoretical and actual values yields Debye temperatures consistent with results from other studies determined through thermal analysis methods. This displays the ability of variable-temperature Mössbauer spectroscopy to approximate Debye temperatures and recoil-free fractions, whilst observing temperature induced transitions over the temperature range observed. X-ray diffraction and Rietveld refinement show an inverse relationship between FeO6 octahedral volume and approximated Debye temperatures. Raman spectroscopy show an increase in the band positions attributed to soft modes of Ag symmetry, Ag(3) and Ag(5) from La to GdFeO3 corresponding to octahedral rotations and tilts in the [0 1 0] and [1 0 1] planes respectively.

  13. Solubility and superconductivity in RE(Ba2-xREx)Cu3O7+δ (RE = Nd, Sm, Eu, Gd, Dy)

    International Nuclear Information System (INIS)

    Zhang, K.; Dabrowski, B.; Segre, C.U.; Hinks, D.G.; Schuller, I.K.; Jorgensen, J.D.; Slaski, M.

    1987-10-01

    Solid solutions of RE(Ba 2-x RE x )Cu 3 O 7- δ (RE=Nd,Sm,Eu,Gd,Dy) for x=0 to x=0.5 have been investigated. X-ray and resistivity measurements show that there exists a solid solution region, through which, the structure changes from orthorhombic to tetragonal and the superconducting properties are depressed. The solubility limits depend strongly on the size of the rare-earth ion, with the smallest (Dy) showing no appreciable solubility. The superconducting transition temperature versus x for all of the rare-earth ion substitutions falls on a universal curve, indicating that the Ba sites are extremely ionic and magnetically isolated. 20 refs., 4 figs

  14. Thermal decomposition of RE(C2H5CO2)3·H2O (RE = Dy, Tb, Gd, Eu and Sm)

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude

    2014-01-01

    The thermal decomposition of Dy(III), Tb(III), Gd(III), Eu(III), and Sm(III) propionate monohydrates was studied in argon by means of simultaneous differential thermal analysis and thermogravimetry, infrared-spectroscopy, X-ray diffraction, and optical microscopy. After dehydration, which takes p...

  15. Ion-irradiation resistance of the orthorhombic Ln2TiO5 (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb and Dy) series

    International Nuclear Information System (INIS)

    Aughterson, Robert D.; Lumpkin, Gregory R.; Ionescu, Mihail; Reyes, Massey de los; Gault, Baptiste; Whittle, Karl R.; Smith, Katherine L.; Cairney, Julie M.

    2015-01-01

    The response of Ln 2 TiO 5 (where Ln is a lanthanide) compounds exposed to high-energy ions was used to test their suitability for nuclear-based applications, under two different but complementary conditions. Eight samples with nominal stoichiometry Ln 2 TiO 5 (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb and Dy), of orthorhombic (Pnma) structure were irradiated, at various temperatures, with 1 MeV Kr 2+ ions in-situ within a transmission electron microscope. In each case, the fluence was increased until a phase transition from crystalline to amorphous was observed, termed critical dose D c . At certain elevated temperatures, the crystallinity was maintained irrespective of fluence. The critical temperature for maintaining crystallinity, T c , varied non-uniformly across the series. The T c was consistently high for La, Pr, Nd and Sm 2 TiO 5 before sequential improvement from Eu to Dy 2 TiO 5 with T c 's dropping from 974 K to 712 K. In addition, bulk Dy 2 TiO 5 was irradiated with 12 MeV Au + ions at 300 K, 723 K and 823 K and monitored via grazing-incidence X-ray diffraction (GIXRD). At 300 K, only amorphisation is observed, with no transition to other structures, whilst at higher temperatures, specimens retained their original structure. The improved radiation tolerance of compounds containing smaller lanthanides has previously been attributed to their ability to form radiation-induced phase transitions. No such transitions were observed here. - Highlights: • First ion-irradiation studies on a number of novel compounds including Pr 2 TiO 5 , Eu 2 TiO 5 and Tb 2 TiO 5 . • Systematic in-situ ion-irradiation study of almost complete Ln 2 TiO 5 series (Ln = lanthanides) with orthorhombic crystal structure type. • The first grazing incidence study of bulk irradiated Dy 2 TiO 5 looking for irradiation induced phase transition.

  16. Distribution behavior of uranium, neptunium, rare-earth elements ( Y, La, Ce, Nd, Sm, Eu, Gd) and alkaline-earth metals (Sr,Ba) between molten LiClKCI eutectic salt and liquid cadmium or bismuth

    Science.gov (United States)

    Kurata, M.; Sakamura, Y.; Hijikata, T.; Kinoshita, K.

    1995-12-01

    Distribution coefficients of uranium neptunium, eight rare-earth elements (Y, La, Ce, Pr, Nd, Sm, Eu and Gd) and two alkaline-earth metals (Sr and Ba) between molten LiCl-KCI eutectic salt and either liquid cadmium or bismuth were measured at 773 K. Separation factors of trivalent rare-earth elements to uranium or neptunium in the LiCl-KCl/Bi system were by one or two orders of magnitude larger than those in the LiCl-KCl/Cd system. On the contrary, the separation factors of alkaline-earth metals and divalent rare-earth elements to trivalent rare-earth elements were by one or two orders of magnitude smaller in the LiCl-KCl/Bi system.

  17. Synthesis and characterization of heterobinuclear (La-Zn, Pr-Zn, Nd-Zn, Sm-Zn, Eu-Zn, Gd-Zn, Tb-Zn, Dy-Zn) azine-bridged complexes

    International Nuclear Information System (INIS)

    Singh, Bachcha; Srivastav, A.K.; Singh, P.K.

    1997-01-01

    Zinc(II) complex of 2-acetylpyridine salicyl aldazine (Haps) of the type Zn(aps) 2 (H 2 O) 2 has been synthesised. The reaction of Zn(aps) 2 (H 2 O) 2 with lanthanide chlorides, LnCl 3 (where Ln=La, Pr, Nd, Sm, Eu, Gd, Tb and Dy) yields azine-bridged heterobinuclear complexes of the formulae LnCl 3 Zn(aps) 2 (H 2 O) 2 . These complexes have been characterized by elemental analyses, molecular weight, conductance (solid and solution) and magnetic susceptibility measurements, mass, IR and electronic spectral data. X-ray powder diffraction data indicate the tetragonal unit lattice for Zn(aps) 2 (H 2 O) 2 and PrCl 3 Zn(aps) 2 (H 2 O) 2 . (author)

  18. Distribution behavior of uranium, neptunium, rare-earth elements (Y, La, Ce, Nd, Sm, Eu, Gd) and alkaline-earth metals (Sr,Ba) between molten LiCl-KCl eutectic salt and liquid cadmium or bismuth

    International Nuclear Information System (INIS)

    Kurata, M.; Sakamura, Y.; Hijikata, T.; Kinoshita, K.

    1995-01-01

    Distribution coefficients of uranium neptunium, eight rare-earth elements (Y, La, Ce, Pr, Nd, Sm, Eu and Gd) and two alkaline-earth metals (Sr and Ba) between molten LiCl-KCl eutectic salt and either liquid cadmium or bismuth were measured at 773 K. Separation factors of trivalent rare-earth elements to uranium or neptunium in the LiCl-KCl/Bi system were by one or two orders of magnitude larger than those in the LiCl-KCl/Cd system. On the contrary, the separation factors of alkaline-earth metals and divalent rare-earth elements to trivalent rare-earth elements were by one or two orders of magnitude smaller in the LiCl-KCl/Bi system. (orig.)

  19. In pursuit of the rhabdophane crystal structure: from the hydrated monoclinic LnPO{sub 4}.0.667H{sub 2}O to the hexagonal LnPO{sub 4} (Ln = Nd, Sm, Gd, Eu and Dy)

    Energy Technology Data Exchange (ETDEWEB)

    Mesbah, Adel, E-mail: adel.mesbah@cea.fr [ICSM, UMR 5257 CNRS – CEA – ENSCM – Université de Montpellier, Site de Marcoule - Bât 426, BP 17171, 30207 Bagnols/Cèze (France); Clavier, Nicolas [ICSM, UMR 5257 CNRS – CEA – ENSCM – Université de Montpellier, Site de Marcoule - Bât 426, BP 17171, 30207 Bagnols/Cèze (France); Elkaim, Erik [Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Szenknect, Stéphanie; Dacheux, Nicolas [ICSM, UMR 5257 CNRS – CEA – ENSCM – Université de Montpellier, Site de Marcoule - Bât 426, BP 17171, 30207 Bagnols/Cèze (France)

    2017-05-15

    The dehydration process of the hydrated rhabdophane LnPO{sub 4}.0.667H{sub 2}O (Ln = La to Dy) was thoroughly studied over the combination of in situ high resolution synchrotron powder diffraction and TGA experiments. In the case of SmPO{sub 4}.0.667H{sub 2}O (monoclinic, C2), a first dehydration step was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2) with Z =12 and a =17.6264(1) Å, b =6.9704(1) Å, c =12.1141(1) Å, β=133.74(1) °, V =1075.33(1) Å{sup 3}. In agreement with the TGA and dilatometry experiments, all the water molecules were evacuated above 220 °C yielding to the anhydrous form, which crystallizes in the hexagonal P3{sub 1}21 space group with a =7.0389(1) Å, c =6.3702(1) Å and V =273.34(1) Å{sup 3}. This study was extended to selected LnPO{sub 4}.0.667H{sub 2}O samples (Ln= Nd, Gd, Eu, Dy) and the obtained results confirmed the existence of two dehydration steps before the stabilization of the anhydrous form, with the transitory formation of LnPO{sub 4}.0.5H{sub 2}O. - Graphical abstract: The dehydration process of the rhabdophane SmPO{sub 4}.0.667H{sub 2}O was studied over combination of in situ high resolution synchrotron powder diffraction and TGA techniques, a first dehydration was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2). Then above 220 °C, the anhydrous form of the rhabdophane SmPO{sub 4} was stabilized and crystallizes in the hexagonal P3{sub 1}21 space group. - Highlights: • In situ synchrotron powder diffraction was carried out during the dehydration of the rhabdopahe LnPO{sub 4}.0.667H{sub 2}O. • The heat of the rhabdophane LnPO{sub 4}.0.667H{sub 2}O leads to LnPO{sub 4}.0.5H{sub 2}O then to anhydrous rhabdophane LnPO{sub 4}. • LnPO{sub 4}.0.5H{sub 2}O (monoclinic, C2) and LnPO{sub 4} (Hexagonal, P3{sub 1}21) were solved over the use of direct methods.

  20. Luminescence of Sm, Eu and Tb in compounds with heptafluoroheptanedione and possibility to use in analysis

    International Nuclear Information System (INIS)

    Kononenko, L.I.; Kravchenko, T.B.; Bel'tyukova, S.V.; Kuz'min, V.E.; Suprinovich, E.S.

    1980-01-01

    Proposed is heptafluoroheptanedione - 2.4 (HFHD) as a luminescent reagent on Eu 3+ , Sm 3+ , Tb 3+ . Complex formation of rare earths with HFHD approaches maximum at 7.5-8.5 pH. The formed complex compounds of rare earths with HFHD are well extracted from aqueous solutions by a number of organic solvents, Isub(lum) of the extracts is the same as that of the complex in aqueous-ethanol solution. The given method permits to determine Eu, Sm, Tb microquantities in Y, La, Sm, Gd, Tb, Yb and Lu oxides. Variation coefficient does not exceed 6.5 %

  1. ions (RE = La, Pr, Nd, Sm, Gd and Dy)

    Indian Academy of Sciences (India)

    ) zirconia), tendency of phase transformation (tetragonal to monoclinic () zirconia) and lattice strain were studied with mechanical property e.g. tensile strength of sol–gel derived ZrO2–2 mol% RE2O3 (RE = La, Pr, Nd, Sm, Gd and Dy) spun ...

  2. Redox potentials of the Sm3+/Sm2+ and Eu3+/Eu2+ in molten potassium and cesium chlorides

    International Nuclear Information System (INIS)

    Novoselova, A.V.; Shishkin, V.Yu.; Khokhlov, V.A.

    2000-01-01

    Redox potentials of Sm 3+ /Sm 2+ and Eu 3+ /Eu 2+ in KCl and CsCl melts, containing 4.5 mol.% of samarium and europium chlorides at most, towards chlorine reference electrode in the temperature ranges of 1073-1223 and 973-1173 R respectively were measured by direct potentiometric method. It is shown that the shift of Sm 3+ /Sm 2+ and Eu 3+ /Eu 2+ redox potentials towards their more negative values with increase in the solvent salt cation radius and temperature decrease stems from strengthening of interparticle bonds in the complex groupings [ru

  3. Interband transitions in 106Pd, 152Sm, 152Gd and 182W

    International Nuclear Information System (INIS)

    Kartashov, V.M.; Oborovskij, A.I.; Troitskaya, A.G.

    1990-01-01

    Internal transitions in 106 Pd, 152 Sm, 152 Gd, 182 W nuclei, observed during decay of 152,152m Eu, 182,183 Ta, 106m Ag, are studied. The experimental characteristics of E0-transitions and E0-components of E0+M1+E2 type transitions in the studied nuclei, relative intensities of internal conversion electron lines during 182 Ta decay, multipolar composition and forbidden factor for 182 W and 183 W low-energy transitions, characteristics of transitions are presented

  4. Structure-dependent photo- and infrared-stimulated luminescence of Eu2+ and Sm3+ in CaS:Eu, Sm

    International Nuclear Information System (INIS)

    Wu Jianping; Newman, David; Viney, Ian V.F.

    2002-01-01

    In this paper, delayed photoluminescence (DPL) and infrared-stimulated luminescence (ISL) spectra of Eu 2+ and Sm 3+ in CaS:Eu, Sm have been investigated. It is found that Eu 2+ and Sm 3+ show different characteristic luminescence in DPL. The explanation is based on the fact that Eu 2+ ideally have the same local environment in the lattice position while Sm 3+ have a more complicated local environment due to charge compensation. By studying ISL spectroscopy of CaS:Eu, Sm, different ISL behaviour has also been found. Since defects are formed in CaS:Eu, Sm by replacing divalent calcium with trivalent samarium in the lattice position, the ISL in CaS : Eu, Sm is thought to be contributed by combination of Sm 3+ itself and defects formed in charge compensation. (author)

  5. Facile Fabrication and Properties of Gd2O3:Eu3+, Y2O3:Eu3+ Nanophosphors and Gd2O3:Eu3+/Silica, Y2O3:Eu3+/Silica Nanocomposites

    Science.gov (United States)

    Anh, Tran Kim; Chau, Pham Thi Minh; Hai, Nguyen Thi Quy; Ha, Vu Thi Thai; Van Tuyen, Ho; Bounyavong, Sengthong; Thanh, Nguyen Trong; Minh, Le Quoc

    2018-01-01

    Gd2O3:Eu3+ and Y2O3:Eu3+ nanophosphors have been successfully fabricated by a combustion method at low temperature (350°C) in a short time (5 min) using natriethylenediaminetetraacetic acid (EDTA-Na2) as fuel. The structure, morphology and size of Gd2O3:Eu3+ and Y2O3:Eu3+ nanophosphors have been determined by x-ray diffraction and field emission scanning electron microscopy. Photoluminescence spectra indicated that the optimum Eu3+ ion concentrations with the strongest luminescence emission intensities are 5 mol.% for Y2O3:Eu3+ and 7 mol.% for Gd2O3:Eu3+. The nanocomposites of Gd2O3:Eu3+/silica and Y2O3:Eu3+/silica were fabricated by a sol-gel process with tetraethoxysilane (TEOS) as matrix material, and the nanocomposite compositions were analyzed by energy dispersion spectra. The strongest luminescence peaks from the 5D0-7F2 transition of the Eu3+ ion in Gd2O3:Eu3+ and Y2O3:Eu3+ nanophosphors are between 613 nm and 615 nm. The Gd2O3:Eu3+ and Y2O3:Eu3+ nanophosphors and their silica nanocomposites were studied to elucidate the influences of the Eu3+ concentration, host materials, annealing temperature, and weight ratio of TEOS and Gd2O3:Eu3+ or Y2O3:Eu3+.

  6. Temperature dependence of spin and orbital magnetic moments of Sm 4f electrons in (Sm, Gd)Al2

    International Nuclear Information System (INIS)

    Qiao, S.; Kimura, A.; Adachi, H.; Iori, K.; Miyamoto, K.; Xie, T.; Namatame, H.; Taniguchi, M.; Tanaka, A.; Muro, T.; Imada, S.; Suga, S.

    2005-01-01

    X-ray magnetic circular dichroism studies were carried out on (Sm, Gd)Al 2 , a ferromagnet without net magnetization at a certain compensation temperature. For Sm 4f electrons, the following understandings were obtained: the magnitude of expectation value of orbital magnetic moment (m L Sm ) is always larger than that of spin one (m S Sm ), so the cancellation of total spin and orbital magnetic moments cannot be achieved only by Sm 4f electrons and the contributions from Gd ions and conduction electrons are important; when the temperature decreases, the magnitude of both m L Sm and m S Sm increases and the gross magnetic moment due to the Sm 4f electrons monotonically deviates from zero. These results tell us that the temperature dependence of magnetic moments related with the electrons other than Sm 4f ones may play important roles in the subtle adjustment of the total spin and orbital magnetic moments to the zero magnetization at the compensation temperature

  7. Isomer decay spectroscopy of 164Sm and 166Gd: midshell collectivity around N=100.

    Science.gov (United States)

    Patel, Z; Söderström, P-A; Podolyák, Zs; Regan, P H; Walker, P M; Watanabe, H; Ideguchi, E; Simpson, G S; Liu, H L; Nishimura, S; Wu, Q; Xu, F R; Browne, F; Doornenbal, P; Lorusso, G; Rice, S; Sinclair, L; Sumikama, T; Wu, J; Xu, Z Y; Aoi, N; Baba, H; Bello Garrote, F L; Benzoni, G; Daido, R; Fang, Y; Fukuda, N; Gey, G; Go, S; Gottardo, A; Inabe, N; Isobe, T; Kameda, D; Kobayashi, K; Kobayashi, M; Komatsubara, T; Kojouharov, I; Kubo, T; Kurz, N; Kuti, I; Li, Z; Matsushita, M; Michimasa, S; Moon, C-B; Nishibata, H; Nishizuka, I; Odahara, A; Şahin, E; Sakurai, H; Schaffner, H; Suzuki, H; Takeda, H; Tanaka, M; Taprogge, J; Vajta, Zs; Yagi, A; Yokoyama, R

    2014-12-31

    Excited states in the N=102 isotones 166Gd and 164Sm have been observed following isomeric decay for the first time at RIBF, RIKEN. The half-lives of the isomeric states have been measured to be 950(60) and 600(140) ns for 166Gd and 164Sm, respectively. Based on the decay patterns and potential energy surface calculations, including β6 deformation, a spin and parity of 6- has been assigned to the isomeric states in both nuclei. Collective observables are discussed in light of the systematics of the region, giving insight into nuclear shape evolution. The decrease in the ground-band energies of 166Gd and 164Sm (N=102) compared to 164Gd and 162Sm (N=100), respectively, presents evidence for the predicted deformed shell closure at N=100.

  8. Isomer Decay Spectroscopy of Sm 164 and Gd 166 : Midshell Collectivity Around N =100

    Science.gov (United States)

    Patel, Z.; Söderström, P.-A.; Podolyák, Zs.; Regan, P. H.; Walker, P. M.; Watanabe, H.; Ideguchi, E.; Simpson, G. S.; Liu, H. L.; Nishimura, S.; Wu, Q.; Xu, F. R.; Browne, F.; Doornenbal, P.; Lorusso, G.; Rice, S.; Sinclair, L.; Sumikama, T.; Wu, J.; Xu, Z. Y.; Aoi, N.; Baba, H.; Bello Garrote, F. L.; Benzoni, G.; Daido, R.; Fang, Y.; Fukuda, N.; Gey, G.; Go, S.; Gottardo, A.; Inabe, N.; Isobe, T.; Kameda, D.; Kobayashi, K.; Kobayashi, M.; Komatsubara, T.; Kojouharov, I.; Kubo, T.; Kurz, N.; Kuti, I.; Li, Z.; Matsushita, M.; Michimasa, S.; Moon, C.-B.; Nishibata, H.; Nishizuka, I.; Odahara, A.; Şahin, E.; Sakurai, H.; Schaffner, H.; Suzuki, H.; Takeda, H.; Tanaka, M.; Taprogge, J.; Vajta, Zs.; Yagi, A.; Yokoyama, R.

    2014-12-01

    Excited states in the N =102 isotones Gd 166 and Sm 164 have been observed following isomeric decay for the first time at RIBF, RIKEN. The half-lives of the isomeric states have been measured to be 950(60) and 600(140) ns for Gd 166 and Sm 164 , respectively. Based on the decay patterns and potential energy surface calculations, including β6 deformation, a spin and parity of 6- has been assigned to the isomeric states in both nuclei. Collective observables are discussed in light of the systematics of the region, giving insight into nuclear shape evolution. The decrease in the ground-band energies of Gd 166 and Sm 164 (N =102 ) compared to Gd 164 and Sm 162 (N =100 ), respectively, presents evidence for the predicted deformed shell closure at N =100 .

  9. Absorption Spectra of BaF2 Sm2O3, Sm, Gd, and Ho Plasmas

    Science.gov (United States)

    Martin, Michael; Bastiani-Ceccotti, Serena

    2009-11-01

    Knowledge of the opacities of high Z element plasmas is important in indirect drive ICF and the study of stellar evolution. There are few experimental measurements of this quantity, and its theoretical determination is difficult due to the number of possible bound electron configurations. This study aims to better the theoretical understanding of this parameter by looking at the 3d-4f transitions of BaF2, Sm2O3, Sm, Gd, and Ho plasmas at the LULI2000 facility. The plasmas are produced by radiative heating and are cold, 15 -- 40 eV, and relatively dense, ˜ .01gm/cm^3 A plasma is produced by a .5 ns laser pulse irradiating a gold hohlraum and then probed by an x-ray source created by a gold foil irradiated by a 10 ps laser pulse. The transmission is found with simultaneous source and absorption measurements by an x-ray spectrometer in the 8 - 20 å range We will compare the results with statistical atomic structure codes. From this experiment we will gain further insight into the spectral broadening of neighboring Z elements due to changing plasma temperature and into mixture thermodynamics. This is a first step towards an experimental study of astrophysical domains.

  10. L-shell X-ray production cross sections of Ce, Nd, Sm, Eu, Gd, and Dy by impact of {sup 14}N{sup 2+} ions with energies between 7.0 MeV and 10.5 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, G.; Méndez, B.; López-Monroy, J. [Departamento de Aceleradores, Instituto Nacional de Investigaciones Nucleares, Carr. México-Toluca S/N, Ocoyoacac, Edo. Méx. 52750 (Mexico); Miranda, J., E-mail: miranda@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México, Cd. Mx. 01000 (Mexico); Villaseñor, P. [Departamento de Aceleradores, Instituto Nacional de Investigaciones Nucleares, Carr. México-Toluca S/N, Ocoyoacac, Edo. Méx. 52750 (Mexico)

    2016-09-15

    Highlights: • A new data set of L X-ray production cross sections by nitrogen ion impact is given. • The target elements have atomic numbers in the range 58–66 (lanthanoids). • A universal scaling as function of a reduced velocity variable is applied. • The eCPSSR model with EC and MI corrections gives very good results. - Abstract: L-shell X-ray production cross sections from the lanthanoid elements Ce, Nd, Sm, Eu, Gd, and Dy, induced by the impact of {sup 14}N{sup 2+} ions with energies in the interval 7.0 MeV to 10.5 MeV (0.50 MeV/μ to 0.75 MeV/μ), were measured and then compared with theoretical calculations obtained with the ECPSSR model with exact limits of integration (eCPSSR) and related corrections. These include the electron capture by the incoming ion and multiple ionizations of higher shells. Data from this work were contrasted with previously published L X-ray production cross sections for {sup 14}N{sup 2+} ion impact. As with other ions, a universal behavior is found when L{sub α} and L{sub γ} X-ray production cross sections are plotted as a function of reduced velocity parameters. The agreement with theoretical predictions was very good when the corrections were applied to the eCPSSR model.

  11. Properties of the (Sm sub 0 sub . sub 3 sub 3 Eu sub 0 sub . sub 3 sub 3 Gd sub 0 sub . sub 3 sub 3)Ba sub 2 Cu sub 3 O sub y superconductor prepared by different processes in air

    CERN Document Server

    Giovannelli, F; Monot-Laffez, I

    2003-01-01

    Bars and pellets of the (Sm sub 0 sub . sub 3 sub 3 Eu sub 0 sub . sub 3 sub 3 Gd sub 0 sub . sub 3 sub 3)Ba sub 2 Cu sub 3 O sub x superconductor were processed in air, using the floating zone method and the top-seeded melt-textured growth method, respectively. The samples were prepared using different experimental conditions, i.e. maximal processing temperature, translation rate or cooling rate. Their physical properties and their microstructure were studied. All the samples exhibit a satisfying superconducting transition whereas the critical current density greatly depends on the processing parameters. The sample prepared by the floating zone method at 1070 deg C with a translation rate of 2 mm h sup - sup 1 exhibits a very high J sub c value of 70000 A cm sup - sup 2 in the self-field and more than 30000 A cm sup - sup 2 at 1.7 T. The pellet processed at 1080 deg C with a cooling rate of 2 deg C h sup - sup 1 has a high J sub c reaching about 56000 A cm sup - sup 2 in the self-field and more than 32000 A ...

  12. Sm isotope composition and Sm/Eu ratio determination in an irradiated 153Eu sample by ion exchange chromatography-quadrupole inductively coupled plasma mass spectrometry combined with double spike isotope dilution technique

    International Nuclear Information System (INIS)

    Bourgeois, M.; Isnard, H.; Gourgiotis, A.; Stadelmann, G.; Gautier, C.; Mialle, S.; Nonell, A.; Chartier, F.

    2011-01-01

    Within the framework of the research undertaken by the French Atomic Energy Commission on transmutation of long-lived radionuclides, targets of highly enriched actinides and fission products were irradiated in the fast neutron reactor Phenix. Precise and accurate measurements of the isotopic and elemental composition of the enriched elements are therefore required. In order to obtain the uncertainties of several per mil and to reduce handling time and exposure to analyst on radioactive material, the on-line coupling of ion exchange chromatography with quadrupole inductively coupled plasma mass spectrometry has been associated with the technique of the double spike isotope dilution. We present in this paper the results obtained on an irradiated sample of Europium oxide powder (enriched at 99.13% in 153 Eu). After irradiation of around 5 mg of Eu 2 O 3 powder the theoretical calculations predict the formation of several micrograms of gadolinium and samarium isotopes. In relation to the very high activity of the sample after irradiation and the very low quantity of Sm formed, the on-line ion exchange chromatography separation of Gd, Sm and Eu before Sm isotope ratio measurements has been developed for the quantification of the 152 Sm/ 153 Eu ratio. These on-line measurements were associated with the double spike isotope dilution technique after calibration of a 147 Sm/ 151 Eu spike solution. The external reproducibility of Sm isotopic ratios was determined to be around 0.5% (2 σ) resulting in a final uncertainty on the 152 Sm/ 153 Eu ratio of around 1% (2 σ). These on-line measurements present therefore a robust and high-throughput alternative to the thermal-ionisation mass spectrometry technique used so far in combination with off-line chromatographic separation, particularly in nuclear applications where characterisation of high activity sample solutions is required. (authors)

  13. EuO and Gd-doped EuO thin films. Epitaxial growth and properties

    Energy Technology Data Exchange (ETDEWEB)

    Sutarto, Ronny

    2009-07-06

    this respect the quality of many of the doped EuO samples used in the past bulk studies. The focus of this thesis is on the preparation and the properties of high-quality single-crystalline EuO and Gd-doped EuO thin films. The so-called Eu-distillation-assisted molecular beam epitaxy (MBE) has been employed to achieve full control of the stoichiometry. The films have been epitaxially grown on yttria-stabilized cubic zirconia (YSZ) (001) substrates. By a systematic variation of the oxygen deposition rates, we have been able to observe sustained oscillations in the intensity of the reflection high-electron energy diffraction (RHEED) pattern during growth. We thus have demonstrated that layer-by-layer growth has been achieved for the first time. We also have confirmed that YSZ indeed supplies oxygen during the initial stages of growth, yet the EuO stoichiometry can still be well maintained. In the case of Gd-doped EuO films, the presence of Gd even helps to stabilize the layer-by-layer growth mode. It is important to achieve this growth mode, since it enables the preparation of films with very smooth and at surfaces. This in turn facilitates the capping of the films with a thin Al overlayer in order to protect the films against degradation under ambient conditions. More important, the smoothness of the lm will enable the preparation of high quality device structures. By using ex-situ soft x-ray absorption spectroscopy (XAS) at the Eu and Gd M{sub 4,5} edges, we have confirmed that the films are completely free from Eu{sup 3+} contaminants, and we were able to determine reliably the actual Gd concentration. This actual Gd concentration could in fact significantly deviate from the nominal Gd/Eu evaporation ratio. From magnetization and susceptibility measurements, we found the Curie temperature to increase smoothly as a function of doping from 69 K up to a maximum of 125 K, all with a saturation moment of 7 {mu}B. A threshold behavior was not observed for Gd concentrations

  14. EuO and Gd-doped EuO thin films. Epitaxial growth and properties

    International Nuclear Information System (INIS)

    Sutarto, Ronny

    2009-01-01

    quality of many of the doped EuO samples used in the past bulk studies. The focus of this thesis is on the preparation and the properties of high-quality single-crystalline EuO and Gd-doped EuO thin films. The so-called Eu-distillation-assisted molecular beam epitaxy (MBE) has been employed to achieve full control of the stoichiometry. The films have been epitaxially grown on yttria-stabilized cubic zirconia (YSZ) (001) substrates. By a systematic variation of the oxygen deposition rates, we have been able to observe sustained oscillations in the intensity of the reflection high-electron energy diffraction (RHEED) pattern during growth. We thus have demonstrated that layer-by-layer growth has been achieved for the first time. We also have confirmed that YSZ indeed supplies oxygen during the initial stages of growth, yet the EuO stoichiometry can still be well maintained. In the case of Gd-doped EuO films, the presence of Gd even helps to stabilize the layer-by-layer growth mode. It is important to achieve this growth mode, since it enables the preparation of films with very smooth and at surfaces. This in turn facilitates the capping of the films with a thin Al overlayer in order to protect the films against degradation under ambient conditions. More important, the smoothness of the lm will enable the preparation of high quality device structures. By using ex-situ soft x-ray absorption spectroscopy (XAS) at the Eu and Gd M 4,5 edges, we have confirmed that the films are completely free from Eu 3+ contaminants, and we were able to determine reliably the actual Gd concentration. This actual Gd concentration could in fact significantly deviate from the nominal Gd/Eu evaporation ratio. From magnetization and susceptibility measurements, we found the Curie temperature to increase smoothly as a function of doping from 69 K up to a maximum of 125 K, all with a saturation moment of 7 μB. A threshold behavior was not observed for Gd concentrations as low as 0.2 %. Analysis of the

  15. Luminescence and energy transfer of Sm3+ and Eu3+ in Ca2PO4Cl

    International Nuclear Information System (INIS)

    Wang, Zhijun; Li, Panlai; Yang, Zhiping; Guo, Qinglin

    2014-01-01

    Sm 3+ , Eu 3+ , and Sm 3+ –Eu 3+ doped Ca 2 PO 4 Cl phosphors are synthesized by a solid-state method. Ca 2 PO 4 Cl:Sm 3+ can produce red emission under the 400 nm radiation excitation, and the emission peak is located at 601 nm, which is assigned to the 4 G 5/2 → 6 H 7/2 transition of Sm 3+ . Ca 2 PO 4 Cl:Eu 3+ can create red emission under the 392 nm radiation excitation, and the strongest peak is located at 620 nm, which is attributed to the 5 D 0 → 7 F 2 transition of Eu 3+ . The energy transfer from Sm 3+ to Eu 3+ in Ca 2 PO 4 Cl has been validated and the critical distance (R c ) of Sm 3+ to Eu 3+ in Ca 2 PO 4 Cl is calculated to be 1.14 nm. With increasing Eu 3+ doping concentration, the energy transfer efficiency (Sm 3+ →Eu 3+ ) gradually increases to 53.7%. The luminescence property of Ca 2 PO 4 Cl:Sm 3+ , Eu 3+ can be tuned by properly tuning the relative ratio of Sm 3+ –Eu 3+ , and the emission intensity of Ca 2 PO 4 Cl:Eu 3+ can be greatly enhanced by codoped Sm 3+ . - Highlights: • Ca 2 PO 4 Cl:Sm 3+ , Eu 3+ can produce red emission under the 400 nm radiation excitation. • The energy transfer from Sm 3+ to Eu 3+ in Ca 2 PO 4 Cl has been validated. • The critical distance of Sm 3+ to Eu 3+ in Ca 2 PO 4 Cl is calculated to be 1.14 nm

  16. Synthesis, luminescence and nonlinear optical properties of homoleptic tetracyanamidogermanates ARE[Ge(CN{sub 2}){sub 4}] (A = K, Cs, and RE = La, Ce, Pr, Nd, Sm, Eu, Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Dolabdjian, Konstantin; Schedel, Christine; Meyer, Hans-Juergen [Abteilung fuer Festkoerperchemie und Theoretische Anorganische Chemie, Institut fuer Anorganische Chemie, Universitaet Tuebingen (Germany); Enseling, David; Juestel, Thomas [Fachbereich Chemieingenieurwesen, FH Muenster, Steinfurt (Germany)

    2017-04-04

    Two new series of tetracyanamidogermanates were prepared by solid-state reaction of appropriate amounts of REF{sub 3} (RE = rare earth), A{sub 2}[GeF{sub 6}] (A = alkaline), and Li{sub 2}(CN{sub 2}) in evacuated silica tubes. Powder X-ray diffraction patterns of crystalline samples of KRE[Ge(CN{sub 2}){sub 4}] and CsRE[Ge(CN{sub 2}){sub 4}] were indexed isotypically to KRE[Si(CN{sub 2}){sub 4}] and RbRE[Ge(CN{sub 2}){sub 4}], respectively. Luminescence properties of Ce{sup 3+}, Eu{sup 3+}, and Tb{sup 3+} doped compounds and non-linear optical properties (NLO) of KRE[Ge(CN{sub 2}){sub 4}] are reported. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Synthesis, structural characterization and Mössbauer study of LnV{sub 0.5}Fe{sub 0.5}O{sub 3} perovskites (Ln = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er)

    Energy Technology Data Exchange (ETDEWEB)

    Ivashita, Flávio F.; Biondo, Valdecir; Bellini, Jusmar V.; Paesano, Andrea [Departamento de Física, Universidade Estadual de Maringá, Av. Colombo 5790, 87.020-900 Maringá, PR (Brazil); Blanco, M. Cecilia; Fuertes, Valeria C.; Pannunzio-Miner, Elisa V. [INFIQC-CONICET, Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba (Argentina); Carbonio, Raúl E., E-mail: carbonio@fcq.unc.edu.ar [INFIQC-CONICET, Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba (Argentina)

    2012-09-15

    Graphical abstract: Mössbauer spectra taken at 200 K for the Y(V{sub 0.5}Fe{sub 0.5})O{sub 3} orthoferrivanadate synthesized by arc-melting. Highlights: ► LnFe{sub 0.5}V{sub 0.5}O{sub 3} were synthesized by the first time for most of the rare-earth elements. ► These orthoferrivanadates crystallize metastably with the perovskite structure. ► Iron and vanadium are trivalent stabilized in these solid solutions. ► The Mössbauer quadrupolar splitting is correlated with the tolerance factor. ► Below 100 K, these perovskites undergo a crystallographic phase transformation. -- Abstract: Perovskites LnV{sub 0.5}Fe{sub 0.5}O{sub 3} (Ln = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er) were synthesized by rapid solidification from arc-melted samples and characterized by the study of their crystal structure and hyperfine properties. These metastable solid solutions crystallized in the Pbnm symmetry, with the iron and vanadium cations randomly distributed in the transition metal octahedral sites. Depending on the lanthanide present at the A site of the perovskite, iron is present with two valences (i.e., Fe{sup 3+} and Fe{sup 2+}). The volume of the unit cell for these perovskites increases linearly with the lanthanide ionic radius, as the perovskite approaches its ideal structure. At room temperature, the quadrupolar splitting of the trivalent paramagnetic Mössbauer component works as an indirect measurement for the Goldshmidt tolerance factor. Close to or below 100 K, these perovskites undergo a crystallographic phase transformation, probably due to orbital ordering of the V{sup 3+} cations, originating two different magnetic iron sites.

  18. Synthesis, structures, and luminescent properties of sodium rare-earth metal(III) chloride oxotellurates(IV), Na{sub 2}Ln{sub 3}Cl{sub 3}[TeO{sub 3}]{sub 4} (Ln = Sm, Eu, Gd, Tb, Dy, and Ho)

    Energy Technology Data Exchange (ETDEWEB)

    Charkin, Dmitri O.; Dorofeev, Sergey G.; Berdonosov, Peter S.; Dolgikh, Valery A. [Department of Chemistry, Lomonosov Moscow State University (Russian Federation); Zitzer, Sabine; Greiner, Stefan; Schleid, Thomas [Institut fuer Anorganische Chemie, Universitaet Stuttgart (Germany); Olenev, Andrei V. [Department of Chemistry, Lomonosov Moscow State University (Russian Federation); Sine Theta Ltd., Moscow (Russian Federation)

    2017-11-17

    Six sodium rare-earth metal(III) chloride oxotellurates(IV), Na{sub 2}Ln{sub 3}Cl{sub 3}[TeO{sub 3}]{sub 4}, isostructural to Na{sub 2}Y{sub 3}Cl{sub 3}[TeO{sub 3}]{sub 4}, were synthesized by flux techniques and characterized by single-crystal XRD. The compounds crystallize in the monoclinic space group C2/c with lattice constants a = 23.967(1), b = 5.6342(3), c = 16.952(1) Aa, β = 134.456(5) for Ln = Sm, a = 23.932(2), b = 5.6044(5), c = 17.134(1) Aa, β = 135.151(6) for Ln = Eu, a = 23.928(1), b = 5.5928(1), c = 17.1133(8) Aa, β = 135.366(3) for Ln = Gd, a = 23.907(1), b = 5.569(3), c = 16.745(1) Aa, β = 134.205(3) for Ln = Tb, a = 23.870(1), b = 5.547(3), c = 16.665(1) Aa, β = 134.102(3) for Ln = Dy, and a = 23.814(1), b = 5.526(3), c = 16.626(1) Aa, β = 134.016(3) for Ln = Ho and Z = 4. Their crystal structure can be considered as a framework built of intergrowing Ln-O and Na-(O,Cl) slabs with channel walls decorated by tellurium atoms of [TeO{sub 3}]{sup 2-} groups. The luminescent properties of the new compounds due to the Ln{sup 3+} cations are described and discussed. We also discuss the crystal chemistry of various alkali-metal rare-earth metal(III) halide oxochalcogenates(IV). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Isomer Decay Spectroscopy of Sm-164 and Gd-166: Midshell Collectivity Around N=100

    OpenAIRE

    Patel, Z; Soederstroem, P-A; Podolyak, Z; Regan, PH; Walker, PM; Watanabe, H; Ideguchi, E; Simpson, GS; Liu, HL; Nishimura, S; Wu, Q; Xu, FR; Browne, F; Doornenbal, P; Lorusso, G

    2014-01-01

    © 2014 American Physical Society. Excited states in the N=102 isotones Gd166 and Sm164 have been observed following isomeric decay for the first time at RIBF, RIKEN. The half-lives of the isomeric states have been measured to be 950(60) and 600(140) ns for Gd166 and Sm164, respectively. Based on the decay patterns and potential energy surface calculations, including β6 deformation, a spin and parity of 6- has been assigned to the isomeric states in both nuclei. Collective observables are disc...

  20. The isolation and the separation of Sm, Gd, Dy by extraction

    International Nuclear Information System (INIS)

    Biyantoro, D.; Lahagu, F.; Basuki, K.T.; Handini, T.; Rosyidin

    1996-01-01

    The isolation of yttrium and separation of Sm, Gd, y with extraction has been investigated. The steps of the process include of this research were the production the concentrate of lanthanide, the dilution, the isolation of yttrium, and the separation of the Sm, Gd, Dy. The first step was the digestion of xenotime sand, the extraction, the dilution, the filtration, the precipitation, the baking production a lanthanide oxide. The step was the separation of yttrium, the stripping, and the calcination production of yttrium oxide. And the third process was the separation of Sm, Gd, Dy by extraction process using method liquid-liquid extraction with extractant of D 2 EHPA and a solvent of dodecane. From the result have been found concentration of yttrium oxide = 88,71 %. The optimum condition of the separation of Gd/Dy have been found : the concentration of HNO 3 = 0,5 M, time of extraction = 15 minutes, and the concentration of extractant = 30 % D 2 EHPA in dodecane. The results of this condition were the distribution coefficient of Gd = 2,226, the distribution coefficient of Dy = 3,762, and the separation factor of Gd/Dy = 0,592. (author)

  1. Role of some rare earth (RE) ions (RE= La, Pr, Nd, Sm, Gd and Dy ...

    Indian Academy of Sciences (India)

    ) zirconia), tendency of phase transformation (tetragonal to monoclinic () zirconia) and lattice strain were studied with mechanical property e.g. tensile strength of sol–gel derived ZrO2–2 mol% RE2O3 (RE = La, Pr, Nd, Sm, Gd and Dy) spun ...

  2. (RE) ions (RE = La, Pr, Nd, Sm, Gd and Dy) in crystal and ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Crystal behaviours such as crystallization temperature (amorphous to tetragonal (t) zirconia), tendency of phase transformation (tetragonal to monoclinic (m) zirconia) and lattice strain were studied with mechanical property e.g. tensile strength of sol–gel derived ZrO2–2 mol% RE2O3 (RE = La, Pr, Nd, Sm, Gd.

  3. Spherical and rod-like Gd2O3:Eu nanophosphors—Structural and ...

    Indian Academy of Sciences (India)

    6Glass Technology Lab, Central Glass and Ceramic Research Institute (CSIR), Kolkata 700 032, India. MS received 8 ... hydrothermal product shows hexagonal Gd(OH)3:Eu3+ phase and it converts to pure cubic phase of Gd2O3:Eu3+ on calcination ... An improved performance of displays and lamps requires high quality of ...

  4. Spherical and rod-like Gd2O3:Eu nanophosphors—Structural and ...

    Indian Academy of Sciences (India)

    5Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India ... hydrothermal product shows hexagonal Gd(OH)3:Eu3+ phase and it converts to pure cubic phase of Gd2O3:Eu3+ on calcination at 600◦C for 3 h. .... peaks using the Scherrer's equation (Klug and Alexander. 1954) d = 0·9 λ.

  5. Spherical and rod-like Gd2O3: Eu 3 nanophosphors—Structural and ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 35; Issue 4. Spherical and rod-like Gd2O3:Eu3+ nanophosphors—Structural and luminescent properties. N Dhananjaya H ... The strong red emission of cubic Gd2O3:Eu3+ nanophosphors by hydrothermal method are promising for high performance display materials.

  6. Facile combustion synthesis of novel CaZrO 3: Eu 3, Gd 3 red ...

    Indian Academy of Sciences (India)

    The obtained deposits were characterized by XRD, TGA-DSC, SEM, EDS, PL measurements and microscope fluorescence. When the Gd3+ ions were introduced in this compound, the emissions of CaZrO3:Eu3+ were remarkably enhanced. The emission spectrum of CaZrO3:Eu3+, Gd3+ nanocrystals exhibited a red shift ...

  7. The temperature dependence studies of rare-earth (Dy.sup.3+./sup., Sm.sup.3+./sup., Eu.sup.3+./sup. and Tb.sup.3+./sup.) activated Gd.sub.3./sub.Ga.sub.3./sub.Al.sub.2./sub.O.sub.12./sub. garnet single crystals

    Czech Academy of Sciences Publication Activity Database

    Bartosiewicz, Karol; Babin, Vladimir; Beitlerová, Alena; Boháček, Pavel; Jurek, Karel; Nikl, Martin

    2017-01-01

    Roč. 189, Sep (2017), s. 126-139 ISSN 0022-2313 R&D Projects: GA ČR GA16-15569S EU Projects: European Commission(XE) 316906 - LUMINET Institutional support: RVO:68378271 Keywords : Gd3Ga3Al2O12 * rare earth dopants * energy transfer * thermal quenching * single crystal Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 2.686, year: 2016

  8. Structural trends in a series of isostructural lanthanide-copper metallacrown sulfates (Ln(III) = Pr, Nd, Sm, Eu, Gd, Dy and Ho): hexaaquapentakis[μ3-glycinehydroxamato(2-)]sulfatopentacopper(II)lanthanide(III) heptaaquapentakis[μ3-glycinehydroxamato(2-)]sulfatopentacopper(II)lanthanide(III) sulfate hexahydrate.

    Science.gov (United States)

    Pavlishchuk, Anna V; Kolotilov, Sergey V; Fritsky, Igor O; Zeller, Matthias; Addison, Anthony W; Hunter, Allen D

    2011-07-01

    The seven isostructural complexes, [Cu(5)Ln(C(2)H(4)N(2)O(2))(5)(SO(4))(H(2)O)(6.5)](2)(SO(4))·6H(2)O, where Ln(III) = Pr, Nd, Sm, Eu, Gd, Dy and Ho, are representatives of the 15-metallacrown-5 family. Each dianion of glycinehydroxamic acid (GlyHA) links two Cu(II) cations forming a cyclic [CuGlyHA](5) frame. The Ln(III) cations are located at the centre of the [CuGlyHA](5) rings and are bound by the five hydroxamate O atoms in the equatorial plane. Five water molecules are coordinated to Cu(II) cations, and one further water molecule, located close to an inversion centre between two adjacent [Cu(5)Ln(GlyHA)(5)](2+) cations, is disordered around this inversion centre and coordinated to a Cu(II) cation of either the first or second metallacrown ether. Another water molecule and one of the two crystallographically independent sulfate anions are coordinated, the latter in a bidentate fashion, to the Ln(III) cation in the axial positions. The second sulfate anion is not coordinated to the cation, but is located in an interstitial position on a crystallographic inversion centre, thus leading to disorder of the O atoms around the centre of inversion. The Ln-O bond distances follow the trend of the lanthanide contraction. The apical Ln-O bond distances are very close to the sums of the ionic radii. However, the Ln-O distances within the metallacrown units are slightly compressed and the Ln(III) cations protrude significantly from the plane of the otherwise flat metallacrown ligand, thus indicating that the cavity is somewhat too small to accommodate the Ln(III) ions comfortably. This effect decreases with the size of the lanthanide cation from complex (I) (Ln(III) = Pr; 0.459) to complex (VII) (Ln(III) = Ho; 0.422), which indicates that the smaller lanthanide cations fit the cavity of the pentacopper metallacrown ring better than the larger ones. The diminished contraction of Ln-O distances within the metallacrown planes leads to an aniostropic contraction of the unit

  9. Shape tunable synthesis of Eu-and Sm-doped ZnO microstructures ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 38; Issue 6. Shape tunable synthesis of Eu- and Sm-doped ZnO microstructures: a morphological evaluation ... FESEM images depicted the formation of Eu-doped ZnO microsphere and Sm-doped ZnO microplates. XRD spectra showed single crystalline nature of the ...

  10. Orange and reddish-orange light emitting phosphors: Sm{sup 3+} and Sm{sup 3+}/Eu{sup 3+} doped zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Meza-Rocha, A.N., E-mail: ameza@fis.cinvestav.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México D.F., México (Mexico); Speghini, A. [Dipartimento di Biotecnologie, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); IFAC CNR, Nello Carrara Institute of Applied Physics, MDF Lab, I-50019 Sesto Fiorentino, FI (Italy); Bettinelli, M. [Dipartimento di Biotecnologie, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); Caldiño, U. [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México D.F., México (Mexico)

    2015-11-15

    A spectroscopy study of Sm{sup 3+} and Sm{sup 3+}/Eu{sup 3+} doped zinc phosphate glasses is performed through photoluminescence spectra and decay time profile measurements. Under Sm{sup 3+} excitation at 344 nm, the Sm{sup 3+} singly doped glass shows an orange global emission with x=0.579 and y=0.414 CIE1931 chromaticity coordinates, whereas the Sm{sup 3+}/Eu{sup 3+} co-doped sample exhibits orange overall emissions (x=0.581 and y=0.398, and x=0.595 and y=0.387) and reddish-orange overall emission (x=0.634 and y=0.355) upon excitations at 344, 360 and 393 nm, respectively. Such luminescence from the co-doped sample is originated by the simultaneous emission of Sm{sup 3+} and Eu{sup 3+}. Under Sm{sup 3+} excitation at 344 and 360 nm, the Eu{sup 3+} emission is sensitized and enhanced by Sm{sup 3+} through a non-radiative energy transfer process. The non-radiative nature was inferred from the shortening of the Sm{sup 3+} lifetime observed in the Sm{sup 3+}/Eu{sup 3+} co-doped sample. An analysis of the Sm{sup 3+} emission decay time profiles using the Inokuti–Hirayama model suggests that an electric quadrupole–quadrupole interaction into Sm–Eu clusters might dominate the energy transfer process, with an efficiency of 0.17. - Highlights: • Zinc phosphate glasses are optically activated with Sm{sup 3+}/Eu{sup 3+} (ZPOSmEu). • Non-radiative energy transfer Sm{sup 3+}→Eu{sup 3+} takes place in ZPOSmEu. • ZPOSmEu overall emission can be modulated with the excitation wavelength. • ZPOSmEu might be useful as orange/reddish-orange phosphor for UV-white LEDs.

  11. Energy transfer from Gd{sup 3+} to Eu{sup 3+} in silica xerogels

    Energy Technology Data Exchange (ETDEWEB)

    Szpikowska-Sroka, Barbara, E-mail: barbara.szpikowska-sroka@us.edu.pl; Żądło, Maria; Czoik, Rozalia; Żur, Lidia; Pisarski, Wojciech A.

    2014-10-15

    Luminescent xerogels co-doped with Gd{sup 3+} and Eu{sup 3+} ions were obtained in silica matrix. The effect of gadolinium ions on visible emission of europium ions in prepared xerogels has been studied. Spectroscopic parameters for Eu{sup 3+} and Gd{sup 3+} ions were determined based on excitation and emission measurements as well as luminescence decay analysis. The luminescence decay for the {sup 5}D{sub 0} level of Eu{sup 3+} ions in sample after excitation at 273 nm is almost twice as long in comparison to excitation at 393 nm. The luminescence intensity coefficient R (Eu{sup 3+}) was calculated, and it was found that ratio of the intensity of red to orange line clearly depends on the excitation parameters. Based on these spectroscopic parameters the energy transfer process from Gd{sup 3+} to Eu{sup 3+} ions has been confirmed. - Highlights: • Sol–gel systems co-doped with Gd{sup 3+}/Eu{sup 3+} ions have been fabricated. • Spectroscopic parameters for Eu{sup 3+}were detected under different excitation wavelengths. • Efficient energy transfer from Gd{sup 3+} to Eu{sup 3+} ions was confirmed.

  12. Effect of Gd substitution on structure and spectroscopic properties of (Lu,Gd)2O3:Eu ceramic scintillator

    Science.gov (United States)

    Cao, Maoqing; Hu, Zewang; Ivanov, Maxim; Dai, Jiawei; Li, Chaoyu; Kou, Huamin; Shi, Yun; Chen, Haohong; Xu, Jiayue; Pan, Yubai; Li, Jiang

    2018-02-01

    In this paper, (Lu1-xGdx)2O3:Eu (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9) ceramics were consolidated by the solid-state reaction method combined with vacuum sintering without sintering aids. We investigated the effect of the varying contents of Gd2O3 on the structure and spectroscopic properties of (Lu1-xGdx)2O3:Eu ceramics. X-ray diffraction (XRD) patterns indicate that proper amount of Gd2O3 can incorporate well with Lu2O3 and form Lu2O3-Gd2O3 solid solution. However, excessive Gd3+-doping in Lu2O3 will lead to the cubic phase transforming into monoclinic even hexagonal phase. The Gd3+ substitution no more than 50% of Lu2O3 enhances the radioluminescence, and reduces the fluorescence lifetime. Transmittance, photoluminescence, and radiation damage of the (Lu1-xGdx)2O3:Eu scintillation ceramics were also studied.

  13. Synthesis and photoluminescence properties of Eu3+-doped silica@coordination polymer core-shell structures and their calcinated silica@Gd2O3:Eu and hollow Gd2O3:Eu microsphere products.

    Science.gov (United States)

    Lee, Hee Jung; Park, Ju-Un; Choi, Sora; Son, Juhee; Oh, Moonhyun

    2013-02-25

    The conjugation of Eu(3+)-doped coordination polymers constructed from Gd(3+) and isophthalic acid (H(2)IPA) with silica particles is investigated for the production of luminescent microspheres. A series of doping ratio-controlled silica@coordination polymer core-shell spheres is easily synthesized by altering the amounts of metal nodes used in the reactions, where the ratios of Gd(3+) and Eu(3+) are 10:0 (1a), 9:1 (1b), 8:2 (1c), 7:3 (1d), 5:5 (1e), and 0:10 (1f). The formation of monodisperse uniform core-shell structures is achieved throughout the entirety of a series. Investigations of the photoluminescence property of the resulting series of silica@coordination polymer core-shell spheres reveal that 20% Eu(3+)-doped product (1c) has the strongest emission intensity. The subsequent calcination process on the silica@coordination polymer core-shell structures (1a-f) results in the formation of a series of doping ratio-controlled silica@Gd(2)O(3):Eu core-shell microspheres (2a-f) with uniform shell thickness. During the calcination step, the coordination polymers within silica@coordination polymer core-shells are transformed into metal oxides, resulting in silica@Gd(2)O(3):Eu core-shell structures. The final etching process on the silica@Gd(2)O(3):Eu core-shell microspheres (2a-f) produces a series of hollow Gd(2)O(3):Eu microspheres (3a-f) as a result of the elimination of silica cores. The luminescence intensities of silica@Gd(2)O(3):Eu core-shell (2a-f) and hollow Gd(2) O(3):Eu microspheres (3a-f) also vary depending upon the doping ratio of Eu(3+) ions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Molecular electrophosphorescence in (Sm, Gd)-{beta}-diketonate complex blend for OLED applications

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, R., E-mail: fisicaplic@hotmail.com [Facultad de Ingenieria Quimica y Textil, Universidad Nacional de Ingenieria, UNI, Av. Tupac Amaru 210, Lima 31, Peru (Peru); Cremona, M. [DIMAT - Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial, INMETRO, Duque de Caxias, RJ (Brazil); Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, PUC-Rio, C.P. 38071, Rio de Janeiro, RJ, CEP 22453-970 (Brazil); Teotonio, E.E.S. [Departamento de Quimica, CCEN, Universidade Federal da Paraiba, UFPB, C.P. 5093, Joao Pessoa, PB, CEP 5805-970 (Brazil); Brito, H.F. [Instituto de Quimica, Universidade de Sao Paulo, USP, C.P. 26077, Sao Paulo, SP, CEP 05599-970 (Brazil); Malta, O.L. [Departamento de Quimica Fundamental, CCEN, Universidade Federal de Pernambuco, Cidade Universitaria, Recife, PE, CEP 50670-901 (Brazil)

    2013-02-15

    In this work the preparation and characterization of the triple-layer organic light-emitting diode (OLED) using a mixture of the samarium and gadolinium {beta}-diketonate complexes [Sm{sub 0.5}Gd{sub 0.5}(TTA){sub 3}(TPPO){sub 2}] as emitting layer is reported. The OLED's devices contain 1-(3-methylphenyl)-1,2,3,4-tetrahydroquinoline-6-carboxyaldehyde-1, 1'-diphenylhydrazone (MTCD) as hole-transporting layer and tris(8-hydroxyquinoline aluminum) (Alq{sub 3}) as electron transporting layer. The electroluminescence spectrum present emission narrow bands from the {sup 4}G{sub 5/2}{yields}{sup 6}H{sub J} transitions (where J=5/2, 7/2 and 9/2) characteristic of the Sm{sup 3+} ion. These sharp lines are overlapped with a broad band attributed to the electrophosphorescence from the T{sub 1}{yields}S{sub 0} transition in the ligand TTA. The intramolecular energy transfer is discussed and applied on the change of the emission color of the organic LEDs at different bias voltages. - Highlights: Black-Right-Pointing-Pointer Samarium and gadolinium complexes. Black-Right-Pointing-Pointer OLED with complex blend (Sm,Gd). Black-Right-Pointing-Pointer Electrophosphorescence emission detection. Black-Right-Pointing-Pointer Application in OLED changing the color emission.

  15. New neutron-rich isotope production in 154Sm+160Gd

    Directory of Open Access Journals (Sweden)

    Ning Wang

    2016-09-01

    Full Text Available Deep inelastic scattering in 154Sm+160Gd at energies above the Bass barrier is for the first time investigated with two different microscopic dynamics approaches: improved quantum molecular dynamics (ImQMD model and time dependent Hartree–Fock (TDHF theory. No fusion is observed from both models. The capture pocket disappears for this reaction due to strong Coulomb repulsion and the contact time of the di-nuclear system formed in head-on collisions is about 700 fm/c at an incident energy of 440 MeV. The isotope distribution of fragments in the deep inelastic scattering process is predicted with the simulations of the latest ImQMD-v2.2 model together with a statistical code (GEMINI for describing the secondary decay of fragments. More than 40 extremely neutron-rich unmeasured nuclei with 58≤Z≤76 are observed and the production cross sections are at the order of μb to mb. The multi-nucleon transfer reaction of Sm+Gd could be an alternative way to synthesize new neutron-rich lanthanides which are difficult to be produced with traditional fusion reactions or fission of actinides.

  16. Ferro-paramagnetic coupled resonant modes in GdEuCuO4

    International Nuclear Information System (INIS)

    Fainstein, A.; Tovar, M.

    1990-01-01

    Two paramagnetic resonances were observed in compound GdEuCuO 4 : one was originated in trivalent gadolinium paramagnetism, while the other is associated to a weak ferromagnetic mode in Cu-O planes. In this work, experimental results are presented that show an anisotropy and a strongly anomalous temperature dependence of Gd 3+ . A theoretical model was introduced which explains the data in terms of coupled ferro-paramagnetic resonant modes originated in spin exchange coupling of Cu and Gd. (Author). 9 refs., 4 figs

  17. Luminescent properties and characterization of Gd2O3:Eu3+@SiO2 and Gd2Ti2O7:Eu3+@SiO2 core shell phosphors prepared by a sol gel process

    Science.gov (United States)

    Lin, Kuo-Min; Lin, Chih-Cheng; Li, Yuan-Yao

    2006-03-01

    Gd2O3:Eu3+ and Gd2Ti2O7:Eu3+ films 10 nm in thickness were individually coated onto silica spheres (particle size of 150-170 nm) using the sol-gel method. The synthesized materials were addressed as Gd2O3:Eu3+@SiO2 and Gd2Ti2O7:Eu3+@SiO2 phosphors. An x-ray powder diffractometer (XRD), field emission scanning electron microscope (FE-SEM), high-resolution transmission electron microscope (HR-TEM), and photoluminescence spectrophotometer (PL) were employed to characterize the core-shell phosphors. Uniform core-shell phosphor particles were observed using FE-SEM. The XRD and HR-TEM results indicated that the coated-shell layer was well crystallized after sintering at 1000 °C. The Gd2O3:Eu3+@SiO2 PL measurement showed a red emission at the main 615 nm wavelength. The Gd2Ti2O7:Eu3+@SiO2 phosphor showed an orange-red emission at the 588 and 615 nm wavelengths. In comparison with the Gd2O3:Eu3+ and Gd2Ti2O7:Eu3+ bulk material results, the core-shell phosphors maintained the same emission ability as the bulk materials and the novel core-shell phosphors possessed great potential in quantum phosphor applications.

  18. Luminescent properties and characterization of Gd2O3:Eu(3+)@SiO2 and Gd2Ti2O7:Eu(3+)@SiO2 core-shell phosphors prepared by a sol-gel process.

    Science.gov (United States)

    Lin, Kuo-Min; Lin, Chih-Cheng; Li, Yuan-Yao

    2006-03-28

    Gd2O3:Eu(3+) and Gd2Ti2O7:Eu(3+) films 10 nm in thickness were individually coated onto silica spheres (particle size of 150-170 nm) using the sol-gel method. The synthesized materials were addressed as Gd2O3:Eu(3+)@SiO2 and Gd2Ti2O7:Eu(3+)@SiO2 phosphors. An x-ray powder diffractometer (XRD), field emission scanning electron microscope (FE-SEM), high-resolution transmission electron microscope (HR-TEM), and photoluminescence spectrophotometer (PL) were employed to characterize the core-shell phosphors. Uniform core-shell phosphor particles were observed using FE-SEM. The XRD and HR-TEM results indicated that the coated-shell layer was well crystallized after sintering at 1000 °C. The Gd2O3:Eu(3+)@SiO2 PL measurement showed a red emission at the main 615 nm wavelength. The Gd2Ti2O7:Eu(3+)@SiO2 phosphor showed an orange-red emission at the 588 and 615 nm wavelengths. In comparison with the Gd2O3:Eu(3+) and Gd2Ti2O7:Eu(3+) bulk material results, the core-shell phosphors maintained the same emission ability as the bulk materials and the novel core-shell phosphors possessed great potential in quantum phosphor applications.

  19. Optimization of photoluminescence of GdAl3(BO3)4:Sm3+ phosphors for solid state lighting devices

    Science.gov (United States)

    Jamalaiah, Bungala Chinna

    2017-10-01

    The GdAl3(BO3)4:Sm3+ phosphors prepared by solid-state reaction method were characterized through thermal, structural and photoluminescence studies at room temperature only. The observed X-ray diffraction peaks were well consistent with JCPDS No. 83-1907. When excited with 406 nm wavelength, the studied phosphors exhibit orange-red luminescence through 4G5/2 → 6H5/2, 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2 transitions. The concentration of Sm3+ ions was optimized to be 0.01 mol% for intense luminescence in GdAl3(BO3)4:Sm3+ phosphors. Beyond 0.01 mol% of Sm3+ ions concentration, luminescence quenching was observed due to energy transfer among the excited Sm3+ ions through cross-relaxation and dipole-dipole interaction mechanisms. The GdAl3(BO3)4:0.01 mol% Sm3+ phosphor was identified as a notable host material to emit intense orange-red luminescence for various solid state lighting devices under 406 nm excitation.

  20. Charge density wave formation in R2Te5 (R=Nd, Sm, and Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Shin, K. Y.; Laverock, J.; Wu, Y. Q.; Condron, C.; Toney, M.; Dugdale, S.; Kramer, M.; Fisher, I.

    2008-04-01

    The rare earth (R) tellurides R{sub 2}Te{sub 5} have a crystal structure intermediate between that of RTe{sub 2} and RTe{sub 3}, consisting of alternating single and double Te planes sandwiched between RTe block layers. We have successfully grown single crystals of Nd{sub 2}Te{sub 5}, Sm{sub 2}Te{sub 5}, and Gd{sub 2}Te{sub 5} from a self-flux and we describe here evidence for charge density wave formation in these materials. The superlattice patterns for all three compounds are relatively complex, consisting at room temperature of at least two independent wave vectors. Consideration of the electronic structure indicates that, to a large extent, these wave vectors are separately associated with sheets of the Fermi surface which are principally derived from the single and double Te layers.

  1. Charge Density Wave Formation in R(2)Te(5) (R=Nd, Sm, And Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Shin, K.Y.; Laverock, J.; Wu, Y.Q.; Condron, C.L.; Toney, M.F.; Dugdale, S.B.; Kramer, M.J.; Fisher, I.R.

    2009-05-27

    The rare earth (R) tellurides R{sub 2}Te{sub 5} have a crystal structure intermediate between that of RTe{sub 2} and RTe{sub 3}, consisting of alternating single and double Te planes sandwiched between RTe block layers. We have successfully grown single crystals of Nd{sub 2}Te{sub 5}, Sm{sub 2}Te{sub 5}, and Gd{sub 2}Te{sub 5} from a self-flux and we describe here evidence for charge density wave formation in these materials. The superlattice patterns for all three compounds are relatively complex, consisting at room temperature of at least two independent wave vectors. Consideration of the electronic structure indicates that, to a large extent, these wave vectors are separately associated with sheets of the Fermi surface which are principally derived from the single and double Te layers.

  2. Quasicrystal Approximants in the RE-Au-SM systems (RE = Gd, Tb, Ho, Yb; SM = Si, Ge) : Syntheses, structures and properties

    OpenAIRE

    Gebresenbut, Girma Hailu

    2016-01-01

    In this study, new Tsai-type 1/1 quasicrystal approximants (ACs) in the RE-Au-SM systems (RE = Gd, Tb, Ho, Yb; SM = Si, Ge) were synthesized using high temperature synthesis techniques such as self-flux, arc-melting-annealing and novel arc-melting-self-flux methods. The syntheses not only provided appropriate samples for the intended structural and physical property measurements but could also be adapted to other systems, especially where crystal growth is a challenge. The newly developed arc...

  3. Mutifuntional GdPO4:Eu3+ hollow spheres: synthesis and magnetic and luminescent properties.

    Science.gov (United States)

    Zhang, Lihui; Yin, Meili; You, Hongpeng; Yang, Mei; Song, Yanhua; Huang, Yeju

    2011-11-07

    Mondispersed submicrometer GdPO(4):Eu(3+) hollow spheres were synthesized via an effective one-pot hydrothermal process. These hollow spheres have the average diameter of 200 nm, and the shell thickness is about 20 nm. The surface of the spheres consists of a number of nanorods with diameters of about 10 nm and lengths of about 50-80 nm. Both magnetic and luminescent properties of the obtained Eu(3+)-doped GdPO(4) hollow spheres were investigated. The hysteresis plot (M-H) analysis result indicates their paramagnetic property. The fluorescence spectra demonstrate that they emit orange-red color light originated from the (5)D(0) → (7)F(J) transitions of the Eu(3+) ions. Therefore, the obtained GdPO(4) hollow spheres hold promise for encapsulate drugs with controlled release. Moreover, the GdPO(4):Eu(3+) hollow spheres are attributes for bimodal magnetic resonance imaging (MRI)/optical bioimaging labeling. © 2011 American Chemical Society

  4. Preparation of MAl O : Eu2+, Sm3+ (M = Ca, Sr, Ba) Phosphors by ...

    African Journals Online (AJOL)

    NJD

    2007-10-15

    Oct 15, 2007 ... clearly show that most peaks are assigned to those of the MAl2O4 structure. Moreover, their structures change with change of M. Samples A and B exhibit monoclinic crystal systems and sample. C a hexagonal structure. The doping Eu2+ and co-doping Sm3+ have very little influence on the structure of the ...

  5. Preparation of MAl 2 O 4 : Eu 2+ , Sm 3+ (M = Ca, Sr, Ba) Phosphors ...

    African Journals Online (AJOL)

    A series of MAl2O4: Eu2+, Sm3+ (M = Ca, Sr, Ba) phosphors was prepared by the combustion method, and the influence of these alkaline earth metals on the structure and luminescent performances for these phosphors was investigated. A relationship was established between their composition, crystallization capacity and ...

  6. Measurement of chemical activities of rare earths (RE: Ce, Pr, Sm and Eu) in cadmium alloy

    International Nuclear Information System (INIS)

    Ghosh, Sajal; Ganesan, Rajesh; Sridharan, R.; Gnanasekaran, T.

    2015-01-01

    Activity of rare earth (RE) elements, Ce, Pr, Sm and Eu is measured in each of the cadmium rich binary alloys of RE, by making use of a molten salt based electrochemical cell. The binary alloy consists of a mixture of cadmium rich intermetallic compound and a liquid phase of known composition. Four independent cells are constructed; one for each of the rare earth elements and electromotive force (EMF) is measured as a function of temperature for each cell, respectively. Partial molar Gibbs energy of these rare earth metals in liquid cadmium is derived from the EMF output over a temperature range. Gibbs energy of formation of CeCd 11 , PrCd 11, SmCd 6 and EuCd 11 are deduced from the measured EMF values and the reported literature data on the solubility of rare earth elements in liquid cadmium. - Highlights: • Activities of rare earth (RE) elements such as Ce, Pr, Sm and Eu were measured as a function of temperature in cadmium rich biphasic mixture. • Partial molar Gibbs energies of these rare earths in liquid cadmium were derived over a temperature range. • Gibbs energy of formation of CeCd 11 , PrCd 11, SmCd 6 and EuCd 11 were derived.

  7. Crystal structure of RCoIn5 (R - Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Y) and R2CoIn8 (R - Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Tm, Y) compounds

    International Nuclear Information System (INIS)

    Kalychak, Ya.M.; Zaremba, V.I.; Baranyak, V.M.; Bruskov, V.A.; Zavalij, P.Yu.

    1989-01-01

    Usng X-ray diffraction method of monocrystal, crystal structure of HoCoIn 5 compound belonging to the HoCoGa 5 structural type is determined. Using the method of powder belonging of CeCoIn 5 structure to the HoCoGa 5 structural type is confirmed. Isostructural compounds with Y, Pr, Nd, Sm, Gd, Tb, Dy are detected. Their lattice periods are determined. Using the method of powder belonging of Ce 2 CoIn 8 compound structure to Ho 2 CoGa 8 structural type is determined. Isostructural compounds with Y, Pr, Nd, Sm, Gd, Dy, Ho, Er, Tm are detected and their lattice periods are determined

  8. Influence of Y, Gd and Sm on the glass forming ability and thermal crystallization of aluminum based alloy

    International Nuclear Information System (INIS)

    Aliaga, L.C.R.; Bolfarini, C.; Kiminami, C.S.; Botta Filho, W.J.; Danez, G.P.

    2010-01-01

    Al-based amorphous alloys represent an important family of metals and a great scientific activity has been devoted to determine the main features of both glass forming ability (GFA) and crystallization behavior in order to have a comprehensive framework aimed at potential technological applications. Nowadays, it is well known that the best Al-based amorphous alloys are formed in ternary systems such as Al- RE-TM, where RE is a rare earth and TM a transition metal. This paper presents results of research in Al 85 Ni 10 RE 5 alloys (RE = Y, Gd and Sm). Amorphous ribbons were processed by melt-spinning under the same conditions and subsequently characterized by x-ray diffraction (XRD) and differential scanning calorimetry (DSC). Results show appreciable micro structural differences as function of the rare earth, thus crystal is obtained for Y, nano-glassy for Gd and, fully amorphous structure for Sm. (author)

  9. Effect of Gd doping and O deficiency on the Curie temperature of EuO

    KAUST Repository

    Jutong, Nuttachai

    2015-01-27

    The effect of Gd doping and O deficiency on the electronic structure, exchange interaction, and Curie temperature of EuO in the cubic and tetragonal phases is studied by means of density functional theory. For both defects, the Curie temperature is found to exhibit a distinct maximum as a function of the defect concentration. The existence of optimal defect concentrations is explained by the interplay of the on-site, RKKY, and superexchange contributions to the magnetism.

  10. Gd2O3:Eu3+/PPO/POPOP/PS composites for digital imaging radiation detectors

    Science.gov (United States)

    Oliveira, J.; Martins, P. M.; Martins, P.; Correia, V.; Rocha, J. G.; Lanceros-Mendez, S.

    2015-11-01

    Polymer-based scintillator composites have been produced by combining polystyrene (PS) and Gd2O3:Eu3+ scintillator nanoparticles. Polystyrene has been used since it is a flexible and stable binder matrix, resistant to thermal and light deterioration and with suitable optical properties. Gd2O3:Eu3+ has been selected as scintillator material due to its wide band gap, high density and visible light yield. The optical, thermal and electrical characteristics of the composites were studied as a function of filler content, together with their performance as scintillator material. Additionally 1 wt.% of 2,5-diphenyloxazole (PPO) and 0.01 wt.% of 1,4 di[2-(5phenyloxazolyl)]benzene (POPOP) were introduced in the polymer matrix in order to strongly improve light yield, i.e., the measured intensity of the output visible radiation, under X-ray irradiation. Increasing scintillator filler concentration (from 0.25 to 7.5 wt.%) increases scintillator light yield and decreases the optical transparency of the composite. The addition of PPO and POPOP strongly increased the overall transduction performance of the composite due to specific absorption and re-emission processes. It is thus shown that Gd2O3:Eu3+/PPO/POPOP/PS composites with 0.25 wt.% of scintillator content with fluorescence molecules are suitable for the development of innovative large-area X-ray radiation detectors with huge demand from the industries.

  11. Gd2O3:Eu Nanoparticle-Based Poly(vinylidene fluoride) Composites for Indirect X-ray Detection

    Science.gov (United States)

    Martins, P. M.; Martins, P.; Correia, V.; Rocha, J. G.; Lanceros-Mendez, S.

    2015-01-01

    Polymer-based scintillator composites have been fabricated by combining poly(vinylidene fluoride) (PVDF) and Gd2O3:Eu nanoparticles (50 nm). PVDF has been used since it is a flexible and stable binder matrix and highly resistant to thermal and light deterioration. Gd2O3:Eu has been selected as the scintillator material due to its wide band gap, high density and suitable visible light yield. The structural, mechanical, thermal and electrical characteristics of the composites were studied as a function of filler content, together with their performance as scintillator material. The introduction of Gd2O3:Eu nanoparticles into the PVDF matrix does not influence the morphology of the polymer or the degree of crystallinity. On the other hand, an increase of the Young's modulus when compared to the one of the PVDF matrix is observed for filler contents of 0.1-0.75 wt.%. The introduction of Gd2O3:Eu into the PVDF matrix increases the dielectric constant and DC electrical conductivity as well as the visible light yield in the nanocomposite, being this increase dependent upon Gd2O3:Eu content and x-ray input power. In this way, Gd2O3:Eu/PVDF composites show suitable characteristics to be used as x-ray radiation transducers, in particular for large area applications.

  12. Optical spectroscopy and magnetic behaviour of Sm3+ and Eu3+ cations in Li6Eu1-xSmx(BO3)3 solid solution

    Science.gov (United States)

    Belhoucif, Rekia; Velázquez, Matias; Plantevin, Olivier; Aschehoug, Patrick; Goldner, Philippe; Christian, George

    2017-11-01

    A new borate solid solution series of powders, Li6Eu1-xSmx(BO3)3 (LSEBx, x = 0.35, 0.5, 0.6, 1), were synthesized by solid-state reaction, characterized and their luminescent properties were investigated. The absorption spectra indicate that absorption takes place mainly from the Sm3+6H5/2 ground state, with a strong band at 405 nm. The photoluminescence spectra reveal that the Eu3+ red emission intensity strongly depends on the Sm3+ content x. Judd-Ofelt theory was applied to experimental data for the quantitative determination of phenomenological parameters Ωi (i = 2, 4, 6) Judd Ofelt parameters, radiative transition rates and emission quantum efficiency. Owing to the energy transfer from Sm3+ to Eu3+ the intense red light detected at 613 nm at room temperature under UV or blue light excitation, was improved by ∼35% as compared with Sm3+-free samples. This energy transfer was confirmed by faster decay times of Sm3+ as energy donors. Moreover, the energy transfer between Sm3+ and Eu3+ is unidirectional and irreversible, implying that the energy transfer wastage between Sm3+ and Eu3+ is very low. Magnetic susceptibility (χ) measurements of LSEBx were carried out in the temperature range 2-320 K and are used to compare calculated and experimental energy levels.

  13. Photoluminescence varied by selective excitation in BiGdWO6:Eu3+ phosphor

    Science.gov (United States)

    Pavani, K.; Graça, M. P. F.; Kumar, J. Suresh; Neves, A. J.

    2017-12-01

    Eu3+ doped bismuth gadolinium tungstate (BGW), a simplest member of Aurivillius family of layered perovskites, was synthesized by solid-state reaction method. Structural characterisation has been performed by X-Ray diffraction (XRD), Raman spectroscopy, Fourier Transform Infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Band gap of the host matrix has been calculated using reflectance and absorption spectra. Three different mechanisms were found to explain the excitation of Eu3+ ions and are described in detail. Photoluminescence (PL) spectra of the BGW phosphor doped with Eu3+ ions consist of major emission lines associated with 5D0 → 7FJ (J = 0, 1, 2, 3 and 4) of Eu3+ ion. Site selective PL excitation and emission indicates that Eu3+ ions doped in BiGdWO6 are sensitive to the excitation wavelength without change in the structure. Change in emission spectra were observed when the excitation wavelength was changed. Judd-Ofelt (J-O) parameters were determined from the indirect method to interpret the interactions between the host and dopant ions along with detailed analysis of lifetime measurements.

  14. Luminescence of Eu{sup 3+}/Gd{sup 3+} co-doped silicate sol–gel powders

    Energy Technology Data Exchange (ETDEWEB)

    Szpikowska-Sroka, Barbara, E-mail: barbara.szpikowska-sroka@us.edu.pl [Institute of Chemistry, University of Silesia, Szkolna 9 Street, 40-007 Katowice (Poland); Pawlik, Natalia [Institute of Chemistry, University of Silesia, Szkolna 9 Street, 40-007 Katowice (Poland); Swinarew, Andrzej S. [Institute of Materials Science, University of Silesia, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Pisarski, Wojciech A. [Institute of Chemistry, University of Silesia, Szkolna 9 Street, 40-007 Katowice (Poland)

    2015-10-15

    Eu{sup 3+}/Gd{sup 3+} co-doped silicate sol–gel powders have been successfully obtained. The effect of high concentration of gadolinium ions on visible emission of europium ions in prepared materials has been studied under different excitation wavelengths. Spectroscopic properties of Eu{sup 3+} and Gd{sup 3+} ions in prepared powders were determined based on excitation and emission measurements as well as luminescence decay analysis. In the visible spectral range the observed emission bands correspond to transitions of trivalent Eu{sup 3+} and Gd{sup 3+} ions. The changes of excitation mechanism of optically active dopants significantly affect the increase of luminescence intensities. The luminescence lifetime for the {sup 5}D{sub 0} level of Eu{sup 3+} ions in examined samples upon excitation at λ{sub exc}=273 nm ({sup 8}S{sub 7/2}→{sup 6}I{sub J} transition of Gd{sup 3+}) is about 12 times longer in comparison to excitation at λ{sub exc}=393 nm ({sup 7}F{sub 0}→{sup 5}L{sub 6} transition of Eu{sup 3+}). The luminescence intensity coefficient R (Eu{sup 3+}) was also calculated, and it was found that ratio of the intensity of red to orange emission depends on the excitation wavelength. Based on determined spectroscopic parameters the energy transfer process from Gd{sup 3+} to Eu{sup 3+} ions was confirmed. - Highlights: • Eu{sup 3+}/Gd{sup 3+} co-doped silicate powders have been fabricated. • The emission bands in the visible range correspond to transitions of Eu{sup 3+} and Gd{sup 3+}. • The lifetime for the {sup 5}D{sub 0} state of Eu{sup 3+} upon excitation at 273 nm is strongly prolonged. • Efficient energy transfer from Gd{sup 3+} to Eu{sup 3+} ions was confirmed.

  15. Optical Properties of the Charge-Density-Wave Polychalcogenide Compounds R2Te5 (R=Nd, Sm and Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Pfuner, F.; Degiorgi, L.; /Zurich, ETH; Shin, K.Y.; Fisher, I.R.; /Stanford U., Geballe Lab.

    2010-02-15

    We investigate the rare-earth polychalcogenide R{sub 2}Te{sub 5} (R = Nd, Sm and Gd) charge-density-wave (CDW) compounds by optical methods. From the absorption spectrum we extract the excitation energy of the CDW gap and estimate the fraction of the Fermi surface which is gapped by the formation of the CDW condensate. In analogy to previous findings on the related RTe{sub n} (n = 2 and 3) families, we establish the progressive closing of the CDW gap and the moderate enhancement of the metallic component upon chemically compressing the lattice.

  16. Crystal structure of the Re(Mn, Cu)6 (Re=Ce, Pr, Nd, Sm, Gd) and RE(Mn, Ni)3 (RE=Nd, Sm) compounds

    International Nuclear Information System (INIS)

    Kalychak, Ya.M.; Davydyuk, P.P.; Bodak, O.I.

    1984-01-01

    A crystalline structure of REE(Mn, Cu) 6 compounds is studied by the method of monocrystal and powder using Ce(Mn, Cu) 6 compound as an example. For the Cesub(0.143)Mnsub(0.220)Cusub(0.637) monocrystal a=0.65781(6), c=0.50454(6)nm, a diffraction class is 4/mmm. Isostructural compound lattice periods at Mn content of 0.220 a parts are equal to: a=0.65666(6), c=0.50280(6)nm for Pr(Mn, Cu) 6 ; a=0.6560(3), c=0.5013(3)nm for Nd(Mn, Cu) 6 ; a=0.65220(6), c=0.49975(9)nm for Sm(Mn, Cu) 6 ; a=0.6520(1), c=0.4965(1)nm for Gd(Mn, Cu) 6 . Nd(Mn, Ni) 3 and Sm(Mn, Ni) 3 structures are studied by the powder method. Diffractograms of these compounds are displayed successfully in the P6 3 /mmc space group at a=0.5183(3), c=1.676(1)nm for Smsub(0.25)Mnsub(0.35)Nisub(0.40) and at a=0.5152(2), c=1.6710(6)nm for Ndsub(0.25)Mnsub(0.25)Nisub(0.50). Refinement of the structure is conducted using Sm(Mn, Ni) 3 as an example to confirm the belonging of these compounds to the CeNi 3 type, when disposing Sm atoms in positions of Ce atoms and statistical mixture (Mn, Ni) atoms in positions of Ni atoms

  17. Crystal structure and magnetic properties of RCu5-xPdx (R=Pr, Nd, Sm and Eu) alloys

    International Nuclear Information System (INIS)

    Shah, K.V.; Bonville, P.; Manfrinetti, P.; Provino, A.; Dhar, S.K.

    2009-01-01

    We report the effect of replacing Cu by Pd in RCu 5 (R=Pr, Nd, Sm and Eu). The parent RCu 5 compounds crystallize in the hexagonal CaCu 5 -type structure. The hexagonal symmetry is retained in PrCu 4 Pd and EuCu 5-x Pd x (x=1 and 2) but the crystal structure changes to cubic AuBe 5 -type in PrCu 3 Pd 2 , NdCu 5-x Pd x (x=1 and 2) and SmCu 4 Pd. Substitution with Pd leads to lattice expansion and modifies the magnetic behavior. While PrCu 5 is known to be a van-Vleck paramagnet with a singlet ground state, PrCu 4 Pd and PrCu 3 Pd 2 show ferromagnetic-like behavior at low temperatures. SmCu 4 Pd orders ferromagnetically near 28 K in contrast to the antiferromagnetic nature of the parent SmCu 5 . The divalent nature of the Eu ions in EuCu 5 is retained in the ternary alloys, but the Curie temperature is reduced from 57 to 24.5 and 14.5 K in EuCu 4 Pd and EuCu 3 Pd 2 , respectively, inferred from the location of peak in the heat capacity of these two compounds. The magnetic hyperfine field at the Eu nucleus measured with 151 Eu Moessbauer spectroscopy in the ternary Eu-alloys is comparable to that in EuCu 5 . The magnetic behavior of NdCu 4 Pd is similar to that reported in NdCu 5 . The zero-field-cooled, low-field magnetization of NdCu 3 Pd 2 shows a region of diamagnetic behavior roughly between 21 and 4 K, but the field-cooled response is positive.

  18. Influence of Annealing Temperature and Gd and Eu Concentrations on Structure and Luminescence Properties of (Y,Gd)BO3:Eu3+ Phosphors Prepared by Sol-Gel Method

    Science.gov (United States)

    Lien, N. T. K.; Thang, N. V.; Hung, N. D.; Cuong, N. D.; Kien, N. D. T.; Thang, C. X.; Vuong, P. H.; Viet, D. X.; Khoi, N. T.; Huy, P. T.

    2017-06-01

    Red-emitting Eu3+-doped (Y,Gd)BO3 phosphors have been synthesized by a sol-gel process using metal oxides and boric acid as starting materials and citric acid as chelating agent. The main factors affecting the structure and luminescence properties of the product, such as sintering temperature, chemical composition, and Eu3+ doping concentration, were investigated. X-ray diffraction (XRD) analysis indicated that the phosphors begin to crystallize at sintering temperature of 700°C and become phase pure at 900°C. The average size of the phosphor particles after sintering at 1000°C was determined to be about 30 nm to 50 nm. The (Y,Gd)BO3:Eu3+ phosphors were found to exhibit strong red emission at 611 nm and 625 nm corresponding to the 5D0-7F2 transitions of Eu3+ in the host lattice. The photoluminescence intensity was enhanced by posttreatment at 900°C and remained unchanged at 1000°C. It was also found that the optimal concentration of Gd3+ ions for Eu3+ emission was 35%, and no concentration quenching of the photoluminescence was observed even at Eu3+ doping concentration up to 30%.

  19. Preparation, characterization, emission (Eu3+), and electron spin resonance (Gd3+) studies of Y2-xLnxTi2O7 (Ln=Eu and Gd, x=0.0,0.05)

    Science.gov (United States)

    Kumar, B. Vijaya; Velchuri, Radha; Devi, V. Rama; Prasad, G.; Sreedhar, B.; Bansal, C.; Vithal, M.

    2010-08-01

    Bulk and nanopyrochlore materials of composition Y2-xLnxTi2O7 (Ln=Eu and Gd, x=0.0,0.05) have been prepared by sol-gel method via peroxo titanium complex precursor. All the samples were characterized by powder x-ray diffraction (XRD), Raman spectra, and transmission electron microscopy (TEM). The unit cell parameters were obtained from Rietveld analysis of XRD patterns. The influence of particle size on the emission of Eu3+ (in Y2-xEuxTi2O7), the electron spin resonance (ESR) of Gd3+ (in Y2-xGdxTi2O7) and optical absorption spectra have been studied. The band gap energy of Y1.95Ln0.05Ti2O7 (Ln=Eu and Gd) was determined and compared with parent Y2Ti2O7. The variation in the emission intensity of Eu3+ is accounted with the particle size and short range order. The spin-Hamiltonian parameters of Gd3+ were obtained from the powder ESR spectra. The single-ion anisotropy was taken in to account in the analysis of powder ESR spectra. The crystallite size was obtained from powder XRD and TEM images.

  20. Study of the R-(Zr,W)-(O,N) (R = Y, Nd, Sm, Gd, Yb) oxynitride system

    Energy Technology Data Exchange (ETDEWEB)

    Tessier, Franck, E-mail: Franck.Tessier@univ-rennes1.fr [UMR CNRS 6226 ' Sciences Chimiques de Rennes' , equipe ' Verres et Ceramiques' , Universite de Rennes 1, 35042 Rennes cedex (France); Maillard, Pascal [UMR CNRS 6226 ' Sciences Chimiques de Rennes' , equipe ' Verres et Ceramiques' , Universite de Rennes 1, 35042 Rennes cedex (France); Orhan, Emmanuelle [Laboratoire Science des Procedes Ceramiques et Traitements de Surface, UMR CNRS 6638, Universite de Limoges, 123 Avenue Albert Thomas, 87060 Limoges cedex (France); Chevire, Francois [UMR CNRS 6226 ' Sciences Chimiques de Rennes' , equipe ' Verres et Ceramiques' , Universite de Rennes 1, 35042 Rennes cedex (France)

    2010-02-15

    The replacement of tantalum by the couple Zr/W within the RTa-O-N systems (R = Y, Nd, Sm, Gd, Yb), enables the preparation of novel oxide and oxynitride phases in the R-Zr-W-O-N system. R{sub 2}Zr{sub 2-x}W{sub x}O{sub 7+x} oxides exhibit the fluorite-type (x < 0.9) and scheelite (x {approx} 1) structures. Corresponding oxynitride compositions are of the fluorite-type and show different colors, for example in the case of ytterbium: pale yellow (x = 0.2 or 0.25), green (x = 0.5-0.8) and brown for the tungsten-rich samples (x = 0.9, 1). Photocatalytic activity measurements have been performed to investigate the overall water splitting behavior of these colored phases.

  1. Structural Transformation in Inverse-Perovskite REPt3B (RE = Sm and Gd-Tm) Associated with Large Volume Reduction.

    Science.gov (United States)

    Mondal, Sudipta; Mazumdar, Chandan; Ranganathan, Rajarao; Avdeev, Maxim

    2017-07-17

    In this work, we report the structural phase transformation of tetragonal inverse-perovskite REPt 3 B (RE = Sm, and Gd-Tm) compounds to cubic perovskite structure, with a large volume reduction of about 9% (reduction of the c axis, ∼17%; increase in the a axis, ∼5%). The structural stability of the cubic phase, however, could only be maintained by lowering the lattice parameter of the off-stoichiometric REPt 3 B x (x magnetic transition temperatures in the tetragonal and cubic phases. The different physical properties of these two phases demonstrate the interrelationship between the crystal chemistry and the physics of the system. The synthetic route to cubic REPt 3 B x identified in this work may be utilized to prepare new ternary rare-earth intermetallics in a cubic perovksite form, which was previously found to facilitate unconventional superconductivity.

  2. The study of structural and optical properties of (Eu, La, Sm) codoped ZnO nanoparticles via a chemical route

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Jihui; Zhang, Qi; Han, Qiang; Fang, Yue; Wang, Jiaying; Li, Xiuyan; Liu, Yanqing [Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Siping, 136000 (China); Wang, Dandan [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033 (China); Yang, Jinghai, E-mail: jhyang1@jlnu.edu.cn [Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Siping, 136000 (China); Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033 (China)

    2017-06-15

    The (Eu, La, Sm) ions were doped into ZnO nanoparticles by a chemical route, and the substitution of (Eu, La, Sm) for Zn{sup 2+} ions was proved by analytic techniques of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman, transmission electron microscope (TEM), photoluminescence (PL) and UV–vis absorption spectroscopy. The results revealed that the codoping did not change the wurtzite structure of ZnO nanoparticles, but the diameter of the nanoparticles decreased with increasing the rare earth (RE) doping concentrations. The optical bandgaps calculated through UV–visible absorption spectroscopy were found to decrease from 3.26 to 3.14 eV with increasing the RE doping concentrations, which also proved by the slight shift of UV positions in PL spectra. The sharp red emissions located at 578.2, 590.1 and 615.7 nm were originated from the 4f-4f transitions in Eu{sup 3+} ions under excitation of 325 nm. And these red emissions of Eu{sup 3+} ions showed a strong correlation with the energy storage centers of oxygen vacancies in the samples which was introduced by the other RE ions of La{sup 3+} and Sm{sup 3+} codoping. - Highlights: • Doping of (Eu, La, Sm) ions into ZnO nanoparticles is realized by a chemical route. • Eu{sup 3+}-related red emissions from intra-4f follow a similar trend as broad defect emission. • Red emissions of Eu{sup 3+} enhance with RE codoping due to oxygen vacancies as energy storage centers. • The bandgap can be tuned by RE codoping, which shows a prospect for the visible utilization.

  3. Luminescent properties and energy transfer of Gd{sup 3+}/Eu{sup 3+} co-doped cubic CaCO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yidi; Zou, Haifeng; Zhang, Bowen; Zhou, Xiuqing; Song, Yanhua; Zheng, Keyan [College of Chemistry, Jilin University, Changchun 130012 (China); Shi, Zhan [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China); Sheng, Ye, E-mail: shengye@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China)

    2016-10-15

    Gd{sup 3+} and Eu{sup 3+} ions co-doped CaCO{sub 3} nanoparticles have been successfully synthesized via carbonization method. The emission spectra of co-doped CaCO{sub 3} phosphors in the range of VUV–vis spectral were studied. The results reveal that the co-doped CaCO{sub 3} phosphors show intense red emission in the VUV range because of the Gd{sup 3+} ions as sensitizers. The energy transfer process from Gd{sup 3+} to Eu{sup 3+} in CaCO{sub 3}:Gd{sup 3+}/Eu{sup 3+} phosphors was investigated and discussed in terms of the luminescence spectra and the decay curves, which demonstrated that the energy transfer of Gd{sup 3+}→Eu{sup 3+} is efficient. The mechanism of energy transfer from Gd{sup 3+} to Eu{sup 3+} is a resonant transfer, in which electric dipole–dipole interaction plays a leading role. Furthermore, the effect of doping concentration of Eu{sup 3+} ions on the energy transfer efficiency was also investigated. From the photoluminescence (PL) spectra, it was also found that the incorporation of Na{sup +} ions into CaCO{sub 3}:Gd{sup 3+}/Eu{sup 3+} could lead to a remarkable increase of luminescent intensity due to the charge compensation.

  4. Study on photoluminescence and energy transfer of Eu3+/Sm3+ single-doped and co-doped BaB8O13 phosphors

    Science.gov (United States)

    Lephoto, Mantwa A.; Tshabalala, Kamohelo G.; Motloung, Selepe J.; Ahemen, Iorkyaa; Ntwaeaborwa, Odireleng M.

    2018-04-01

    A series of Sm3+, Eu3+ and Eu3+- Sm3+ doped BaB8O13 were synthesized by using a solution combustion method. When excited at 394 nm, BaB8O13: Eu3+ emits red light, and the strongest peak was located at 614 nm, which is attributed to the 5D0→7F2 transition of Eu3+. BaB8O13: Sm3+ produced red-orange light, and the major emission peak was located at 596 nm under the 402 nm radiation excitation, which is assigned to the 4G5/2→6H7/2 transition of Sm3+. When excited at 402 nm, the PL emission intensity from BaB8O13: 0.05Eu3+; 0.005Sm3+ at 614 nm was enhanced considerably compared to that of the sample without Sm3+, suggesting that energy was transferred from Sm3+ to Eu3+. The Commission International de I‧Eclairage (CIE) chromaticity coordinates of BaB8O13: 0.05Eu3+; 0.005Sm3+ powder phosphor (0.637, 0.362) are located in the red region indicating that the phosphor can serve as a source of red light in LEDs.

  5. Mechanism of luminescent enhancement in Ba{sub 2}GdNbO{sub 6}:Eu{sup 3+} perovskite by Li{sup +} co-doping

    Energy Technology Data Exchange (ETDEWEB)

    Rezende, Marcos Vinicius dos Santos [Departamento de Física, Universidade Federal de Sergipe, 49500-000, Itabaiana, SE (Brazil); Valério, Mario Ernesto Giroldo [Departamento de Física, Universidade Federal de Sergipe, 49100-000 São Cristóvão, SE (Brazil); Mouta, Rodolpho; Diniz, Eduardo Moraes [Departamento de Física, CCET, Universidade Federal do Maranhão, 65085-580 São Luís, MA (Brazil); Paschoal, Carlos William de Araujo, E-mail: paschoal@ufma.br [Departamento de Física, CCET, Universidade Federal do Maranhão, 65085-580 São Luís, MA (Brazil); Department of Materials Science and Engineering, University of California Berkeley, 94720-1760 Berkeley, CA (United States); Department of Physics, University of California Berkeley, 94720-7300 Berkeley, CA (United States)

    2015-02-15

    We investigated the Li{sup +} ion incorporation in Ba{sub 2}GdNbO{sub 6}:Eu{sup 3+} perovskite by atomistic simulations based on energy minimization. We predicted the most probable sites occupied by Eu{sup 3+} and Li{sup +} ions and the related charge-compensation mechanisms involved into these substitutions. The results show that the Eu{sup 3+} and Li{sup +} ions are incorporated mainly at the Gd{sup 3+} site. In the Li{sup +} ion case, there is a charge compensation by Nb{sub Gd}{sup •} {sup •} antisite. The crystal field parameters and the transition levels for the Eu{sup 3+} ion in the BGN:Eu{sup 3+} were calculated with basis on the simulated local symmetry of the Eu{sup 3+} site. The results show that the mechanism of luminescent properties enhancement is the symmetry distortion induced by the Li{sup +} co-doping. - Highlights: • We performed a full defect calculations in Ba{sub 2}GdNbO{sub 6} double perovskite. • We modeled with excellent agreement the optical transition of Ba{sub 2}GdNbO{sub 6}:Eu{sup 3+} crystal. • We explained the mechanism of luminescent enhancement in Ba{sub 2}GdNbO{sub 6}:Eu{sup 3+} perovskite by Li{sup +} co-doping.

  6. An electrochemical approach for removal of radionuclidic contaminants of Eu from153Sm for effective use in metastatic bone pain palliation.

    Science.gov (United States)

    Chakravarty, Rubel; Chakraborty, Sudipta; Khan, Mohammed Sahiralam; Ram, Ramu; Sarma, Haladhar Dev; Dash, Ashutosh

    2018-03-01

    Thermal neutron activation of 152 Sm [ 152 Sm(n,γ) 153 Sm] using natural or isotopically enriched (by 152 Sm) samarium target is the established route for production of 153 Sm used for preparation of 153 Sm-EDTMP for pain palliation in cancer patients with disseminated bone metastases. However, some long-lived radionuclidic contaminants of Eu, such as, 154 Eu (t ½ =8.6y) are also produced during the target activation process. This leads to detectable amount of Eu radionuclidic contaminants in patients' skeleton even years after administration with therapeutic doses of 153 Sm-EDTMP. Further, the presence of such contaminants in 153 Sm raises concerns related to radioactive waste management. The aim of the present study was to develop and demonstrate a viable method for large-scale purification of 153 Sm from radionuclidic contaminants of Eu. A radiochemical separation procedure adopting electroamalgamation approach has been critically evaluated. The influence of different experimental parameters for the quantitative removal radionuclidic contaminants of Eu from 153 Sm was investigated and optimized. The effectiveness of the method was demonstrated by purification of ~37 GBq of 153 Sm in several batches. As a proof of concept, 153 Sm-EDTMP was administered in normal Wistar rats and ex vivo γ-spectrometry of bone samples were carried out. After carrying out the electrolysis under the optimized conditions, the radionuclidic contaminants of Eu could not be detected in purified 153 Sm solution by γ-spectrometry. The overall yield of 153 Sm obtained after the purification process was >85%. The reliability of this approach was amply demonstrated in several batches, wherein the performance remained consistent. Ex vivo γ-spectrometry of bone samples of Wistar rats administered with 153 Sm-EDTMP (prepared using electrochemically purified 153 Sm) did not show photo peaks corresponding to radionuclidic contaminants of Eu. A viable electrochemical strategy for the large

  7. Combustion synthesis and characterization of MV0.5P0.5O4: Sm3+, Tm3+ (M = Gd, La, Y)

    Science.gov (United States)

    Motloung, Selepe J.; Lephoto, Mantwa A.; Tshabalala, Kamohelo G.; Ntwaeaborwa, Odireleng M.

    2018-04-01

    In this paper, GdV0.5P0.5O4: Sm3+, Tm3+, LaV0.5P0.5O4: Sm3+, Tm3+ and YV0.5P0.5O4: Sm3+, Tm3+ phosphor powders were prepared by solution combustion method using urea as a fuel. The phase purity, surface morphology, optical and photoluminescence properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy and photoluminescence spectroscopy. The XRD results indicated that the prepared powders are of a single phase and crystallized in tetragonal structure for Gd and Y systems while monoclinic phase was observed for La system. SEM showed that the samples consisted of mixed structures. The estimated band gaps were 2.2, 2.4 and 2.3 eV for Y, Gd and La systems respectively. The photoluminescence results showed four emission peaks. One peak is assigned to 1G4 - 3H6 transition of Tm3+, and three other emission peaks are attributed to 6G5/2 - 6H5/2, 6G5/2 - 6H7/2 and 6G5/2 - 6H9/2 transitions of Sm3+. The photoluminescent intensity was the highest in the gadolinium system.

  8. Orange-red emitting Gd2Zr2O7:Sm3+: Structure-property correlation, optical properties and defect spectroscopy

    Science.gov (United States)

    Gupta, Santosh K.; Reghukumar, C.; Sudarshan, K.; Ghosh, P. S.; Pathak, Nimai; Kadam, R. M.

    2018-05-01

    Local structure analysis of dopant ion, understanding host to dopant energy transfer dynamics and defects characterization in a doped material which plays an important role in the designing a highly efficient opto-electronic material. In this connection a new Sm3+ doped Gd2Zr2O7 pyrochlore material was synthesized using gel-combustion technique and was characterized systematically using X-ray diffraction (XRD), time resolved photoluminescence spectroscopy (TRPLS), positron annihilation lifetime spectroscopy (PALS) and density functional theory (DFT) based ab-initio calculation. Based on DFT site selective energetics calculation and luminescence decay measurement, it was observed that the Sm3+ was distributed at both Gd3+ and Zr4+ site with higher Sm3+ fraction at the Gd3+ site. PALS was used to probe the presence of defects in the phosphor. In this work intense orange-red emission is realized through manipulating the energy transfer from host defect emission (oxygen vacancies) to Sm3+ which allows color emission from green in undoped to orange-red in doped samples. Effect of dopant concentration and annealing temperature was probed using TRPLS and PALS. These all information is highly important for researcher looking to achieve pyrochlore based phosphor materials with high quantum yield.

  9. Is there lattice contraction in multicomponent metal oxides? Case study for GdVO4:Eu3+ nanoparticles

    International Nuclear Information System (INIS)

    Yang Liusai; Li Liping; Zhao Minglei; Fu Chaochao; Li Guangshe

    2013-01-01

    Metal oxide nanomaterials have been found to have great potential for diverse applications due to their unique relationships between structure and properties. Lattice expansion as particle size reduces was previously considered to be general for metal oxide nanomaterials. It is now a great challenge to see if lattice contraction could be induced by the size effect for metal oxide nanomaterials. ABO 4 metal oxides (e.g., CaWO 4 , GdVO 4 , and CdWO 4 ) are some of the most important functional materials with many applications, while such oxides at the nanoscale are never reported to show a lattice contraction. This work presents a first report on the variation from lattice expansion to lattice contraction by tuning the microstructures of GdVO 4 :Eu 3+ nanocrystals. A hydrothermal method was adopted to synthesize GdVO 4 :Eu 3+ nanocrystals, and then these nanoparticles were calcined at 600 ° C in air. It is found that particle size reduction led to a lattice contraction for the calcined samples, which is in contrast to the lattice expansion observed for the hydrothermally synthesized counterparts or many other metal oxide nanomaterials. In addition, the lattice symmetry of the calcined samples remained almost a constant. The results indicate that the negative surface stress was eliminated by calcination treatment, leading to a homogeneous compression process in the lattice structure of the calcined GdVO 4 :Eu 3+ nanocrystals. Furthermore, Eu 3+ was taken as a structural probe and a luminescence center to study the local environments pertinent to these structural changes and to optimize the photoluminescence performance. (paper)

  10. Pinning performance of (Nd,Eu,Gd)-123 superconductors: Comparison of melt-textured pellet and single crystal

    Czech Academy of Sciences Publication Activity Database

    Jirsa, Miloš; Rameš, Michal; Jurek, Karel; Muralidhar, M.; Das, P.; Koblischka, M.R.; Wolf, T.

    2008-01-01

    Roč. 151, č. 1 (2008), s. 25-30 ISSN 0921-5107 R&D Projects: GA ČR GA202/05/0173; GA MŠk 1P05ME728 Institutional research plan: CEZ:AV0Z10100520 Keywords : high-temperature superconductors * cuprous oxides * superconductivity perovskites, * (Nd,Eu,Gd)BaCuO * ternary compounds * melt-textured materials Subject RIV: BM - Solid Matter Physics ; Magnetism

  11. Facile one-step hydrothermal synthesis and luminescence properties of Eu{sup 3+}-doped NaGd(WO{sub 4}){sub 2} nanophosphors

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Zehan; Cai, Peiqing; Chen, Cuili; Pu, Xipeng; Kim, Sun Il, E-mail: sikim@pknu.ac.kr; Jin Seo, Hyo, E-mail: hjseo@pknu.ac.kr

    2017-06-01

    Eu{sup 3+}-doped NaGd(WO{sub 4}){sub 2} nanophosphors were synthesized via a facile one-step hydrothermal method without any surfactants or a further heat treatment. X-ray powder diffraction (XRD), scanning electron microscope (SEM), fourier transform infrared spectroscopy (FT-IR), the photoluminescence (PL) excitation and emission spectra, and decay curves were used to characterize NaGd(WO{sub 4}){sub 2}:Eu{sup 3+} phosphors. The results show that the Eu{sup 3+}-concentration has little influence on the structure and morphology of the as-synthesized samples. However, pH value plays a vital role on the structure and morphology of NaGd(WO{sub 4}){sub 2}. The well-crystallized sheet-like NaGd(WO{sub 4}){sub 2} phosphors can be obtained only at pH = 5–7. On the basis of the time-dependent synthesis, a possible growth mechanism of sheet-like architectures is proposed. The luminescence properties of NaGd{sub 1-x}Eu{sub x}(WO{sub 4}){sub 2} (0 ≤ x ≤ 1) are investigated. It is found that the charge transfer band of Eu{sup 3+} shifts to lower energy and broadens with increasing the Eu{sup 3+}-concentration. - Highlights: • NaGd(WO{sub 4}){sub 2}:Eu{sup 3+} nanosheets were synthesized by facile one-step hydrothermal method. • Luminescence properties of NaGd(WO{sub 4}){sub 2}:Eu{sup 3+} phosphor were firstly reported. • The CT band of Eu{sup 3+} depends strongly on Eu{sup 3+}-concentrations.

  12. Synthesis, electronic structure and luminescent properties of a new red-emitting phosphor GdBiW2O9:Eu3+

    Science.gov (United States)

    Xie, Zhi; Zhou, Weiwei; Zhao, Wang; Zhang, Hao; Hu, Qichang; Xu, Xuee

    2017-10-01

    Red phosphor of GdBiW2O9:Eu3+ was prepared by solid-state reaction method. The phase purity and structure of the samples were characterized by XRD. The electronic structures of GdBiW2O9 host were estimated by DFT calculation. The PLE and PL spectra were also investigated. The optimal luminescent properties of GdBiW2O9:Eu3+ phosphors were obtained at 900 °C with 40 mol% of Eu3+ concentration. The phosphors can be excited efficiently by 396 nm NUV light and emit intense red light peaking at 618 nm. The results indicate GdBiW2O9:Eu3+ can act as a potential red-emitting phosphor for LEDs application.

  13. Oriented monolayer film of Gd2O3:0.05 Eu crystallites: quasi-topotactic transformation of the hydroxide film and drastic enhancement of photoluminescence properties.

    Science.gov (United States)

    Hu, Linfeng; Ma, Renzhi; Ozawa, Tadashi C; Sasaki, Takayoshi

    2009-01-01

    Caught on film: A semitransparent and intensely luminescent monolayer film of oriented Gd(2)O(3):0.05 Eu platelet crystallites is fabricated by annealing the precursor hydroxide film (see scheme). The photoluminescence properties of the as-transformed film are greatly improved over those of the hydroxide film, and are much more pronounced than those of the corresponding Gd(2)O(3):0.05 Eu powder.

  14. Weak transitions in the {sup 152}Sm from {sup 152} Eu decay

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Ruy M. [Centro Tecnico Aeroespacial (IEAv/CTA), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados; Vanin, Vito R.; Pascholati, Paulo R.; Maidana, Nora L. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2010-07-01

    Full text: Few years ago, we reported (R.M. Castro, V.R. Vanin, P.R. Pascholati, N.L. Maidana and M.S. Dias and M.F.Koskinas, Appl. Rad. Isot. 60, 283, 2004) a gamma-gamma coincidence experiment performed to check the gamma-ray transitions following {sup 152}Eu{sup g} 13-year decay and their placement in the decay scheme for metrological purposes. The main results were the observation of weak transitions, in the range 10{sup -4} to 10{sup -5} gamma-rays per decay, and the exclusion of a relatively intense unplaced line from the list of transitions following {sup 152}Eu{sup g} decay. A new paper (W. D. Kulp, J. L. Wood, J. M. Allmond, J. Eimer, D. Furse, K. S. Krane, J. Loats, P. Schmelzenbach, C. J. Stapels, R.-M. Larimer, E. B. Norman, and A. Piechaczek, Phys. Rev. C 76, 034319, 2007), published in 2007, which investigates the {sup 152}Sm nuclear structure, also reported the observation of many weak gamma-ray transitions by coincidence spectroscopy. Despite important differences in the coincidence detector systems, the total number of coincidence events is similar, and the accuracy and the detection threshold are about the same. Thus, all the 27 new transitions reported by Castro et al. in the {sup 152}Sm decay scheme were conformed by Kulp et al. The measured energies form a consistent dataset, with chi-square equal to 38 (8% probability of being exceeded); however, the intensities form a discrepant data set, with chi-square per degree of freedom equal to 3.6, suggesting that the uncertainties are underestimated by a factor of 2. Besides that, Kulp et al. found some transitions not reported previously. So we decided to check our gamma - gamma coincidence spectrum for the presence of these lines. In this new analysis, we did not observe gamma-ray transitions with energies 137.56 and 1050.1 keV, with upper intensity limits well below the intensities given in Kulp et al. The 210.95 keV transition was observed, but with intensity significantly smaller than that

  15. Online Determination of Sm, Eu and Yb in Environmental Samples by Inductively Coupled Plasma – Optical Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    J. Dilip Kumar

    2007-01-01

    Full Text Available A procedure was developed for the determination of Sm, Eu and Yb in water samples by inductively coupled plasma-optical emission spectrometry (ICP-OES after preconcentration on synthesized 5-(4-pyridyl azo-8-quinolinol supported by Borassus flabellifer inflorescence (BFI. The sorbed element was subsequently eluted with 0.4 M HNO3 and the acid eluates were analyzed by ICP-OES. Under the optimal conditions, Sm, Eu and Yb in aqueous samples were concentrated 100-fold. Recoveries were obtained by the proposed method in the range of 98.6 -99.8%. This method was also applied for the analysis of spiked and natural water samples. The results provide strong evidence to support the hypothesis of an adsorption mechanism.

  16. Study of a new magnetic dipole mode in the heavy deformed nuclei 154Sm, 156Gd, 158Gd, 164Dy, 168Er, and 174Yb by high-resolution electron spectroscopy

    International Nuclear Information System (INIS)

    Bohle, D.

    1985-01-01

    By inelastic electron scattering with high energy resolution a new magnetic dipole mode in heavy, deformed nuclei could be detected. For this the nuclei 154 Sm, 156 Gd, 158 Gd, 164 Dy, 168 Er, and 174 Yb were studied at the Darmstadt electron linear accelerator (DALINAC) at small momentum transfer q ≤ 0.6 fm -1 and low excitation energies. A collective magnetic dipole excitation could be discovered in all nuclei at an excitation energy of E x ≅ 66 δA -1/3 MeV whereby δ means the mass deformation. The transition strength extends in the mean to B(M1)↑ ≅ 1.3 μ N 2 . A systematic study of the nucleus 156 Gd yielded hints to a strong fragmentation of the magnetic dipole strength. A comparison of electron scattering, proton scattering, and nuclear resonance fluorescence experiments shows that the new mode is a pure orbital mode. (orig./HSI) [de

  17. Predictions of thermomagnetic properties of Laves phase compounds: TbAl2, GdAl2 and SmAl2 performed with ATOMIC MATTERS MFA computation system

    Science.gov (United States)

    Michalski, Rafał; Zygadło, Jakub

    2018-04-01

    Recent calculations of properties of TbAl2 GdAl2 and SmAl2 single crystals, performed with our new computation system called ATOMIC MATTERS MFA are presented. We applied localized electron approach to describe the thermal evolution of Fine Electronic Structure of Tb3+, Gd3+ and Sm3+ ions over a wide temperature range and estimate Magnetocaloric Effect (MCE). Thermomagnetic properties of TbAl2, GdAl2 and SmAl2 were calculated based on the fine electronic structure of the 4f8, 4f7 and 4f5 electronic configuration of the Tb3+ and Gd3+ and Sm3+ ions, respectively. Our calculations yielded: magnetic moment value and direction; single-crystalline magnetization curves in zero field and in external magnetic field applied in various directions m(T,Bext); the 4f-electronic components of specific heat c4f(T,Bext); and temperature dependence of the magnetic entropy and isothermal entropy change with external magnetic field - ΔS(T,Bext). The cubic universal CEF parameters values used for all CEF calculations was taken from literature and recalculated for universal cubic parameters set for the RAl2 series: A4 = +7.164 Ka04 and A6 = -1.038 Ka06. Magnetic properties were found to be anisotropic due to cubic Laves phase C15 crystal structure symmetry. These studies reveal the importance of multipolar charge interactions when describing thermomagnetic properties of real 4f electronic systems and the effectiveness of an applied self-consistent molecular field in calculations for magnetic phase transition simulation.

  18. The development of new phosphors of Tb3+/Eu3+ co-doped Gd3Al5O12 with tunable emission

    Science.gov (United States)

    Teng, Xin; Wang, Wenzhi; Cao, Zhentao; Li, Jinkai; Duan, Guangbin; Liu, Zongming

    2017-07-01

    The gadolinium aluminum garnets Gd3Al5O12 (GdAG) activated with Tb3+/Eu3+ were successfully prepared via co-precipitation method at 1500 °C in this work. The crystal structure stabilization, elements analysis, microphotograph, PL/PLE spectra, decay behavior and quantum efficiency were discussed in detail. The metastable GdAG compounds been effectively stabilized by doping with smaller 10 at.% Tb3+, which then allows the development of new phosphors of (Gd0.9-xTb0.1Eux)3Al5O12 (GdAG:Tb3+/Eu3+, x = 0-0.03) for opto-functionality explorations. The PLE/PL spectra displays that the strongest PLE peak was located at ∼276 nm, which overlaps the 8S7/2 → 6IJ transition of Gd3+. Under 276 nm excitation, the phosphors exhibited both Tb3+ and Eu3+ emissions at 548 nm (green, 5D4 → 7F5 transition of Tb3+) and 592 nm (orange-red, 5D0 → 7F1 transition of Eu3+), respectively. The emission intensities of Tb3+ and Eu3+ remarkably varied with the Eu3+ incorporation. As a consequence, the emission color can be readily tuned from approximately green to orange-red. Fluorescence decay analysis found that the lifetime for the Tb3+ emission rapidly decreased conforming to the Tb3+ → Eu3+ energy transfer, and the energy transfer efficiency was calculated. Owing to the Gd3+ → Eu3+ and Gd3+ → Tb3+ energy transfer, the emission intensities of Tb3+ and Eu3+ in (Gd0.9-xTb0.1Eux)AG phosphor were higher than (Y0.87Tb0.1Eu0.03)AG and (Lu0.87Tb0.1Eu0.03)AG system. The (Gd0.9-xTb0.1Eux)AG garnet phosphors developed in this work may serve as a new type of phosphor which hopefully meets the requirements of various lighting and optical display applications.

  19. Luminescence characteristics of undoped and Eu-doped GdCa{sub 4}O(BO{sub 3}){sub 3} single crystals and nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Nikl, M. [Institute of Physics, Czech Academy of Sciences, Cukrovarnicka 10, Prague 16253 (Czech Republic); Klos, A.; Rzepka, A.; Pajaczkowska, A. [Institute of Electronic Materials Technology, ul. Wolczynska 133, 01-919 Warsaw (Poland); Lisiecki, R.; Ryba-Romanowski, W. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okolna 2, 50-422 Wroclaw (Poland); Ganschow, S. [Institute for Crystal Growth, Max Born-Str. 2, 12489 Berlin (Germany); Solarz, P.

    2007-12-15

    Single crystals of GdCa{sub 4}O(BO{sub 3}){sub 3} (GdCOB) pure and doped with Eu concentration of 1 and 4 at% were grown by the Czochralski and micropulling-down methods. The distribution of Eu ions in GdCOB crystals was uniform. The substitutions of Eu{sup 3+} in Gd, Ca(1) and Ca(2) cation sites and eventually formation Eu{sup 2+} have been investigated. The spectroscopic properties of crystals are compared with the properties of nanopowders obtained by sol-gel method. Radioluminescence spectra of undoped GdCOB crystal show the characteristic emission of Gd{sup 3+} at about 312 nm, whereas this emission dramatically decreases in Eu-doped crystals upon X-ray excitation, as well as in Eu-doped nanopowders excited in vacuum ultraviolet (VUV) region. The VUV excitation in the range 125-333 nm for Eu-doped samples leads to strong emission in red coming from the {sup 5}D{sub 0} multiplet of Eu{sup 3+}, only. In the photoluminescence decay kinetics of 312 nm emissions substantial shortening and departure for single exponential decay in Eu-doped samples is clearly observed. Higher Eu doping results in further acceleration of the decay. In undoped GdCOB crystal, the lifetime of the Gd{sup 3+} {sup 6}P{sub 7/2} multiplet is 2.79 ms. The Eu{sup 3+} {sup 5}D{sub 0} decay kinetics monitored at 613 nm are rather constant. Numerical fitting of fully exponential curves, reveals lifetimes 2.7 ms for nanopowder and 2.5 ms for single crystal. The results suggest that this material may be used as a red phosphor in plasma display panels in nanopowder form because of strong excitation band of Eu{sup 3+} luminescence in the 160-200 nm regions. Contrary to nanopowder sample, such an excitation band, attributed to the Gd{sup 3+}-O{sup 2-} charge transfer was not observed in crystal obtained by the micropulling-down method. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Luminescent properties of (Y,Gd)BO3:Bi3+,RE3+ (RE=Eu, Tb) phosphor under VUV/UV excitation

    International Nuclear Information System (INIS)

    Zeng Xiaoqing; Im, Seoung-Jae; Jang, Sang-Hun; Kim, Young-Mo; Park, Hyoung-Bin; Son, Seung-Hyun; Hatanaka, Hidekazu; Kim, Gi-Young; Kim, Seul-Gi

    2006-01-01

    Bi 3+ - and RE 3+ -co-doped (Y,Gd)BO 3 phosphors were prepared and their luminescent properties under vacuum ultraviolet (VUV)/UV excitation were investigated. Strong red emission for (Y,Gd)BO 3 :Bi 3+ ,Eu 3+ and strong green emission for (Y,Gd)BO 3 :Bi 3+ ,Tb 3+ are observed under VUV excitation from 147 to 200 nm with a much broader excitation region than that of single Eu 3+ -doped or Tb 3+ -doped (Y,Gd)BO 3 phosphor. Strong emissions are also observed under UV excitation around 265 nm where as nearly no luminescence is observed for single Eu 3+ -doped or Tb 3+ -doped (Y,Gd)BO 3 . The luminescence enhancement of Bi 3+ - and RE 3+ -co-doped (Y,Gd)BO 3 phosphors is due to energy transfer from Bi 3+ ion to Eu 3+ or Tb 3+ ion not only in the VUV region but also in the UV region. Besides, host sensitization competition between Bi 3+ and Eu 3+ or Tb 3+ is also observed. The investigated phosphors may be preferable for devices with a VUV light 147-200 nm as an excitation source such as PDP or mercury-free fluorescent lamp

  1. Hyperfine fields at some 4d, 5d and 4f impurities in ferromagnetic GdZn and GdCd

    International Nuclear Information System (INIS)

    Kasamatsu, Y.; Kojima, K.; Hihara, T.

    1995-01-01

    Hyperfine (hf) fields at 4d (Y, Nb, Rh, Pd), 5d (Lu, Ta, Ir) and 4f (La, Nd, Sm, Eu) impurities in ferromagnetic GdZn and GdCd have been measured by NMR at 4.2 K. The local moment contributions to the hf field suggest that the impurity moments at the beginning and end of the d series are parallel and antiparallel to Gd moments, respectively. The hf results for 4f impurities are also discussed. ((orig.))

  2. Thermodynamic studies on LnCoO{sub 3} (Ln = Eu, Gd, Tb) by solid-state electrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Abhay; Dash, Smruti; Parida, S.C.; Venugopal, V

    2004-12-14

    Ternary oxides in the systems Ln-Co-O (where Ln = Eu, Gd, Tb) have been prepared by citrate-nitrate gel combustion method and characterized by X-ray powder diffraction method. Appropriate equilibrium phase mixtures were prepared, sintered in high purity argon gas and used for e.m.f. measurement using solid oxide galvanic cell with yttria-stabilized zirconia (YSZ) electrolyte. The e.m.f. values were measured as a function of temperature in the range of 1000-1200 K. The standard molar Gibbs energy of formation of the ternary oxides were calculated from the e.m.f. data.

  3. Electron-hole recombination luminescence in LiYF4:U4+; Eu3+;Tb3+; Gd3+

    International Nuclear Information System (INIS)

    Page, A.G.; Godbole, S.V.; Sastry, M.D.; Sabharwal, S.C.

    2001-01-01

    Photoluminescence, photostimulated luminescence and electron paramagnetic resonance studies were carried out on LiYF 4 and LiYF 4 :U 4+ doped crystals. These investigations have identified presence of Eu 3+ , Tb 3+ and Gd 3+ ions being present in both the crystals arising due to their presence in starting material. On gamma irradiation, U 4+ ions were acting as electron trapping centre, and are responsible in introducing shallow traps in the material. In electron-hole recombination process, Tb 3+ ions were observed to be acting as luminescent centres. (author)

  4. Luminescence and energy transfer properties of Eu{sup 3+} and Gd{sup 3+} in ZrO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Villabona-Leal, E.G. [Posgrado en Ciencias Aplicadas, Facultad de Ciencias, Universidad Autónoma de San Luis Potosí. Av. Salvador Nava, 078290 San Luis Potosí (Mexico); Diaz-Torres, L.A.; Desirena, H. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestrcuturados (EMANA), Centro de Investigaciones en Óptica, A. P.1-948, Gto. 37150 León (Mexico); Rodríguez-López, J.L. [División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica, A.C., Camino Presa San José, Lomas 4a Secc, 78216 San Luis Potosí (Mexico); Pérez, Elías [Instituto de Física, Universidad Autónoma de San Luis Potosí, Alvaro Obregón 64, 78000 San Luis Potosí (Mexico); Meza, Octavio, E-mail: omeza@ifuap.buap.mx [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado Postal J-48, Puebla 72570 (Mexico)

    2014-02-15

    Red luminescence emission in ZrO2:Gd{sup 3+}–Eu{sup 3+} nanocrystal under 250 nm radiation excitation is achieved. These materials exhibit a tetragonal phase that is retained by the presence of lanthanide ions. Thus, a study of the optical properties as a function of the dopant concentration was been carried out without the deleterious effects of having segregation of other crystalline phases. We analyze the emission and lifetime curves as a function of dopant concentration through a rate equation simulation, finding an excellent fitting. As results, the nonradiative and radiative relaxation constants, as well as a quantitative estimation of the energy transfer processes among Eu{sup 3+}, Gd{sup 3+} and O{sup 2−} ions are reported for the first time. The proposed model can be extended (or applicable) to explain the fluorescence dynamics in other nanomaterials doped with Eu{sup 3+} and Gd{sup 3+} under UV excitation. -- Highlights: • ZrO{sub 2} nanocrystal exhibits a tetragonal phase in the presence of Eu and Gd dopants. • Emission and lifetimes as a function of dopant concentration were analyzed by rate equation model. • Quantitative estimation of the energy transfer processes among Eu{sup 3+}, Gd{sup 3+} and O{sup 2−} ions are reported.

  5. Synthesis and Characterization of the Rare-Earth Vanadium Oxyselenides Ln7VO 4Se 8 ( Ln=Nd, Sm, Gd)

    Science.gov (United States)

    Tougait, Olivier; Ibers, James A.

    2000-11-01

    The new compounds Ln7VO4Se8 (Ln=Nd, Sm, Gd) were each prepared by heating V, Se, and the corresponding rare-earth sesquioxide at 1223 K in a sealed fused-silica tube. Single crystals have been grown through the use of an antimony flux. They have been characterized by single-crystal and powder X-ray diffraction measurements and by energy dispersive X-ray analysis. These isostructural compounds crystallize with two formula units in the orthorhombic space group Pbam in cells (at 153 K) of dimensions: Nd7VO4Se8, a=14.3419(9) Å, b=15.5528(10) Å, c=3.9948(3) Å; Sm7VO4Se8, a=14.200(2) Å, b=15.451(2) Å, c=3.9511(6) Å; Gd7VO4Se8, a=14.075(8) Å, b=15.424(6) Å, c=3.903(1) Å. The new structure type comprises four crystallographically independent Ln atoms with three different coordination geometries and one V atom in an octahedral environment. Magnetic measurements reveal that Gd7VO4Se8 is paramagnetic down to 5 K.

  6. Synthesis and characterization of Gd 2O 3:Eu 3+ phosphor nanoparticles by a sol-lyophilization technique

    Science.gov (United States)

    Louis, C.; Bazzi, R.; Flores, Marco A.; Zheng, W.; Lebbou, K.; Tillement, O.; Mercier, B.; Dujardin, C.; Perriat, P.

    2003-07-01

    The characterization and luminescence properties of nanostructured Gd 2O 3:Eu 3+ phosphors synthesized by a sol-lyophilization process are presented. After preparation of gadolinium-based sols from gadolinium nitrate and ammonium hydroxide, the so-prepared sols were freeze dried at -10°C and calcinated at different temperatures. For temperatures lower than 1300 K, highly crystalline samples with the cubic structure can be obtained without concomitant grain growth of the particles (<50 nm). The luminescence spectra contain all possible transitions of Eu 3+ with C2 symmetry and present two major features: an increase of the luminescence efficiencies of the phosphors in comparison with that obtained by solid-state reaction and the presence of an additional peak at about 609 nm at the vicinity of the 5D0→ 7F0…4 transition.

  7. Influence of the Gd.sub.2./sub.BaCuO.sub.5./sub. fine particles on thermoelectric power of melt-textured (Nd-Sm-Gd) Ba.sub.2./sub.Cu.sub.3./sub.O.sub.7 -.delta../sub.

    Czech Academy of Sciences Publication Activity Database

    Okram, G. A.; Muralidhar, M.; Jirsa, Miloš; Murakami, M.

    2004-01-01

    Roč. 402, - (2004), s. 94-97 ISSN 0921-4534 Institutional research plan: CEZ:AV0Z1010914 Keywords : melt-textured materials * thermoelectric power * (Nd,Sm,Gd)Ba 2 Cu 3 O y * Gd 2 BaCuO 5 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.072, year: 2004

  8. Polynuclear coordination precursor compounds for M3Fe5O12 garnets (M = Y, Eu, Gd and Er.

    Directory of Open Access Journals (Sweden)

    LUMINITA PATRON

    2005-09-01

    Full Text Available A new type of complexes compounds (NH46[M3Fe5(C4O5H46(C4O5H36]·16H2O (where M(III = Y, Eu, Gd, Er, (NH46[M3Fe5(C4O6H46(C4O6H36]·16H2O (where M(III = Gd, Er and (NH46[M3Fe5(C6O7H106(C6O7H96]·xH2O (where M(III = Y; x = 8; M(III = Eu, Er; x = 22 [C4O5H42– = malate anion; C4O6H42– = tartarate anion, C6O7H11– = gluconate anion] have been synthesized and characterised by elemental chemical analysis and physico-chemical measurements (IR, UV-Vis spectroscopy and magnetic determinations. The synthetic possibilities offered by the use of these new compounds as potential precursors for garnets have been suggested.

  9. Deposition of silica protected luminescent layers of Eu:GdVO{sub 4} nanoparticles assisted by atmospheric pressure plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Moretti, Elisa, E-mail: elisa.moretti@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, INSTM Venice Research Unit, Via Torino 155/B, 30172 Mestre, Venezia (Italy); Pizzol, Giorgia [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, INSTM Venice Research Unit, Via Torino 155/B, 30172 Mestre, Venezia (Italy); Fantin, Marina; Enrichi, Francesco; Scopece, Paolo [Nanofab-Veneto Nanotech, Via delle Industrie 5, 30175 Marghera, Venezia (Italy); Nuñez, Nuria O.; Ocaña, Manuel [Instituto de Ciencia de Materiales de Sevilla, CSIC-US, Americo Vespucio 49, 41092, Isla de la Cartuja, Sevilla (Spain); Benedetti, Alvise [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, INSTM Venice Research Unit, Via Torino 155/B, 30172 Mestre, Venezia (Italy); Polizzi, Stefano [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, INSTM Venice Research Unit, Via Torino 155/B, 30172 Mestre, Venezia (Italy); Centro di Microscopia Elettronica “Giovanni Stevanato”, Università Ca' Foscari Venezia, Via Torino 155/B, 30172 Mestre, Venezia (Italy)

    2016-01-01

    Eu:GdVO{sub 4} nanophosphors with an average size of 60 nm, synthesized by a facile solvothermal method, were deposited on monocrystalline silicon wafers by a spray-coating technique with artworks anti-counterfeiting applications in mind. Atmospheric pressure plasma jet (APPJ) was used to deposit a silica-based layer on top of the nanometric luminescent layer, in order to improve its adhesion to the substrate and to protect it from the environment. The nanophosphors were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Coating composition was investigated by Fourier transform infrared spectroscopy (FT-IR) and its morphology was characterized by scanning electron microscopy (FEG-SEM). The film thickness was evaluated by means of ellipsometry and adhesion was estimated by a peeling test. Luminescent properties of the nanophosphors deposited and fixed on silicon wafers were also measured. The whole layer resulted well-adhered to the silicon substrate, transparent and undetectable in the presence of visible light, but easily activated by UV light source. - Highlights: • Luminescent films were obtained by spray deposition of Eu:GdVO{sub 4} nanophosphors. • Plasma jet deposition of SiO{sub 2} fixed the nanophosphors on the substrate. • Optical properties of nanophosphors were preserved after deposition-fixing process. • Films well-adhered to the substrate, even after a scotch tape peeling test and a scratch test.

  10. Nanostructured LnBaCo2O6− (Ln = Sm, Gd with layered structure for intermediate temperature solid oxide fuel cell cathodes

    Directory of Open Access Journals (Sweden)

    Augusto E. Mejía Gómez

    2017-04-01

    Full Text Available In this work, we present the combination of two characteristics that are beneficial for solid oxide fuel cell (SOFC cathodic performance in one material. We developed and evaluated for the first time nanostructured layered perovskites of formulae LnBaCo2O6-d with Ln = Sm and Gd (SBCO and GBCO, respectively as SOFC cathodes, finding promising electrochemical properties in the intermediate temperature range. We obtained those nanostructures by using porous templates to confine the chemical reagents in regions of 200-800 nm. The performance of nanostructured SBCO and GBCO cathodes was analyzed by electrochemical impedance spectroscopy technique under different operating conditions using Gd2O3-doped CeO2 as electrolyte. We found that SBCO cathodes displayed lower area-specific resistance than GBCO ones, because bulk diffusion of oxide ions is enhanced in the former. We also found that cathodes synthesized using smaller template pores exhibited better performance.

  11. Syntheses, structure determination, magnetic and thermoelectric properties of quasicrystal approximants in RE-Au-SM systems (RE = Gd, Tb and Yb and SM = Si, Ge)

    OpenAIRE

    Gebresenbut, Girma Hailu

    2014-01-01

    In this study, new compositions of Tsai-type 1/1 quasicrystal approximants Gd(14)Au(70)Si(16), Gd(14)Au(67)Ge(19), Tb(14)Au(70)Si(16) and Yb(16)Au(65)Ge(19)are synthesized using both self-flux and arc-melting-annealing techniques. Both syntheses routes resulted single phase samples. The crystal structures of the compounds are determined by collecting single crystal X-ray and/or powder X-ray and powder neutron diffraction intensities.  The atomic structure refinements indicated that the compou...

  12. Influence of Y, Gd and Sm on the glass forming ability and thermal crystallization of aluminum based alloy; Efeito das terras raras Y, Gd e Sm na tendencia a formacao de amorfo e na cristalizacao termica em ligas a base de aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Aliaga, L.C.R.; Bolfarini, C.; Kiminami, C.S.; Botta Filho, W.J., E-mail: aliaga@ufscar.b [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais; Danez, G.P. [Universidade Federal de Sao Carlos (PPG-CEMUFSCar), SP (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais

    2010-07-01

    Al-based amorphous alloys represent an important family of metals and a great scientific activity has been devoted to determine the main features of both glass forming ability (GFA) and crystallization behavior in order to have a comprehensive framework aimed at potential technological applications. Nowadays, it is well known that the best Al-based amorphous alloys are formed in ternary systems such as Al- RE-TM, where RE is a rare earth and TM a transition metal. This paper presents results of research in Al{sub 85}Ni{sub 10}RE{sub 5} alloys (RE = Y, Gd and Sm). Amorphous ribbons were processed by melt-spinning under the same conditions and subsequently characterized by x-ray diffraction (XRD) and differential scanning calorimetry (DSC). Results show appreciable micro structural differences as function of the rare earth, thus crystal is obtained for Y, nano-glassy for Gd and, fully amorphous structure for Sm. (author)

  13. Controlled synthesis of different multilayer architectures of GdBO{sub 3}:Eu{sup 3+} phosphors and shape-dependent luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Zhihua; Zhang, Nannan; Liu, Yali; Li, Linlin; Gan, Shucai, E-mail: gansc@jlu.edu.cn

    2015-03-01

    Graphical abstract: - Highlights: • Pancake-like/flower-like/leaf-like GdBO{sub 3} were obtained via a hydrothermal method. • Gd(OH){sub 3} nanorods and borates were used as the precursors for the first time. • A dissolution and recrystallization process was happened induced by the excess borax. • Three products have the similar stacked arrangements to reduce the surface energy. • The luminescence properties of GdBO{sub 3}:Eu{sup 3+} are related to shape and crystallinity. - Abstract: Monodisperse pancake-like/flower-like/leaf-like GdBO{sub 3} samples have been successfully synthesized via a designed hydrothermal conversion method using H{sub 3}BO{sub 3}, Na{sub 2}B{sub 4}O{sub 7}·10H{sub 2}O, or NaBO{sub 2}·4H{sub 2}O as boron sources, respectively. It was found that different boron sources have crucial influences on the formation and morphology of the products. The Gd(OH){sub 3} nanorods precursors were prepared through a simple hydrothermal process, which then served as sacrificial templates for the fabrication of GdBO{sub 3} micropancakes/microflowers/microleaves via a hydrothermal conversion process. FT-IR spectra confirm that vaterite-type GdBO{sub 3} can be synthesized by this method. The possible formation mechanisms for different microstructures were put forward on the basis of a series of time-dependent control experiments. The products have similar stacked arrangements driven by the minimization of the interfacial and surface energy of the hydrothermal system. An investigation on the photoluminescence (PL) properties of GdBO{sub 3}:Eu{sup 3+} samples with different morphologies indicates that the PL properties of as-obtained GdBO{sub 3}:Eu{sup 3+} phosphors are strongly dependent on their morphology and crystallinity. The flower-like structure exhibits the strongest red emission.

  14. Effect of Er, Gd, and Nd Co-Dopants on the Properties of Sm-Doped Ceria Electrolyte for IT-SOFC

    Science.gov (United States)

    Arabacı, Aliye

    2017-05-01

    Doped ceria electrolytes of Ce0.8Sm0.20O1.90 (SDC), Ce0.8Er0.08Sm0.12O1.90 (ESDC), Ce0.8Gd0.08Sm0.12O1.90 (GSDC), and Ce0.8Nd0.08Sm0.12O1.90 (NSDC) were prepared by a citric-nitrate combustion process. The thermal decomposition of the precursor was investigated by simultaneous thermogravimetric analysis and differential thermal analysis experiments. The phase structure of the calcined and sintered powders was characterized by X-ray diffraction analysis. All of the samples were fluorite-type ceria-based solid solutions. The calcined and sintered powders were also characterized by Fourier transform infrared spectroscopy. Scanning electron microscopy was used to characterize the samples after calcination and sintering. A relative density over 95 percent of the theoretical density was achieved after the sintering process. Electrical conductivities of the sintered samples were measured using the impedance spectra method. The highest ionic conductivity value was found to be 5.28 × 10-2 S cm-1 at 1023 K (750 °C) for GSDC sintered at 1673 K (1400 °C) for 6 hours.

  15. Czochralski growth and optical properties of Li 6Gd 1-xEu x(BO 3) 3 ( x=0-1) single crystals

    Science.gov (United States)

    Yavetskiy, R. P.; Dolzhenkova, E. F.; Dubovik, M. F.; Korshikova, T. I.; Tolmachev, A. V.

    2005-04-01

    It was shown that a continuous series of Li 6Gd 1-xEu x(BO 3) 3 solid solutions exist within the whole concentration range ( x=0-1). Li 6Gd 1-xEu x(BO 3) 3 ( x=0-0.03; 1) single crystals up to 25 mm in length and up to 20 mm in diameter have been grown by the Czochralski method. The structural perfection of the crystals has been estimated from etch patterns and XPA analysis results. The optical absorption and thermally stimulated luminescence of the grown crystals has been studied.

  16. Spin-glass-like behaviour in IrSr2RECu2O8 (RE=Sm and Eu)

    International Nuclear Information System (INIS)

    Santos-Garcia, A.J. dos; Duijn, J. van; Alario-Franco, M.A.

    2008-01-01

    We report the results of magnetic and specific heat measurements on the 1212-type compounds IrSr 2 RECu 2 O 8 with RE=Sm and Eu, prepared by high-pressure and high-temperature synthesis. The magnetic susceptibility of these compounds shows a large difference in the temperature dependence of the magnetization measured under zero-field-cooled and field-cooled conditions below 87 and 71 K, respectively, and upon further cooling below ∼10 K substantial maxima are observed too. Further AC susceptibility measurements support a glassy behaviour in lower magnetic transitions whereas the specific heat measurements do not show the typical long-range ordering commonly displayed in ferro, ferri or antiferromagnetic transitions. Hysteresis loops suggest the presence of magnetic clusters in the otherwise paramagnetic zone, indicating that these compounds probably display a reentrant spin-glass transition. Results are presented and discussed. - Graphical abstract: IrSr 2 RECu 2 O 8 with RE=Sm and Eu were prepared by high-pressure and high-temperature synthesis. Both samples adopt a M-1212-type perovskite structure and a microdomain texturing of the long c-axis is observed by TEM. A very interesting magnetic behaviour is observed in these materials. A 'cluster by cluster freezing' model is proposed, instead of the classical individual spin freezing one to explain the spin-glass-like behaviour that seems to coexist with weak ferromagnetism in both compounds

  17. Anisotropic magnetization and transport properties of RAgSb2 (R=Y, La-Nd, Sm, Gd-Tm)

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Kenneth D. [Iowa State Univ., Ames, IA (United States)

    1999-11-08

    This study of the RAgSb2 series of compounds arose as part of an investigation of rare earth intermetallic compounds containing antimony with the rare earth in a position with tetragonal point symmetry. Materials with the rare earth in a position with tetragonal point symmetry frequently manifest strong anisotropies and rich complexity in the magnetic properties, and yet are simple enough to analyze. Antimony containing intermetallic compounds commonly possess low carrier densities and have only recently been the subject of study. Large single grain crystals were grown of the RAgSb2 (R=Y, La-Nd, Sm, Gd-Tm) series of compounds out of a high temperature solution. This method of crystal growth, commonly known as flux growth is a versatile method which takes advantage of the decreasing solubility of the target compound with decreasing temperature. Overall, the results of the crystal growth were impressive with the synthesis of single crystals of LaAgSb2 approaching one gram. However, the sample yield diminishes as the rare earth elements become smaller and heavier. Consequently, no crystals could be grown with R=Yb or Lu. Furthermore, EuAgSb2 could not be synthesized, likely due to the divalency of the Eu ion. For most of the RAgSb2 compounds, strong magnetic anisotropies are created by the crystal electric field splitting of the Hund's rule ground state. This splitting confines the local moments to lie in the basal plane (easy plane) for the majority of the members of the series. Exceptions to this include ErAgSb2 and TmAgSb2, which have moments along the c-axis (easy axis) and CeAgSb2, which at intermediate temperatures has an easy plane, but exchange coupling at low temperatures is anisotropic with an easy axis. Additional anisotropy is also observed within the basal plane of DyAgSb2, where the moments are restricted to align along one of the <110> axes. Most of

  18. Phase relations and linear thermal expansion of cubic solid solutions in the Th1-xMxO2-x/2 (M=Eu, Gd, Dy) systems

    International Nuclear Information System (INIS)

    Mathews, M.D.; Ambekar, B.R.; Tyagi, A.K.

    2005-01-01

    Cell parameters and linear thermal expansion studies of the Th-M oxide systems with general compositions Th 1-x M x O 2-x/2 (M=Eu 3+ , Gd 3+ and Dy 3+ , 0.0= 1.5 in the ThO 2 lattice. The upper solid solubility limits of EuO 1.5 , GdO 1.5 and DyO 1.5 in the ThO 2 lattice under conditions of slow cooling from 1673K are represented as Th 0.50 Eu 0.50 O 1.75 , Th 0.60 Gd 0.40 O 1.80 and Th 0.85 Dy 0.15 O 1.925 , respectively. The linear thermal expansion (293-1123K) of MO 1.5 and their single-phase solid solutions with thoria were investigated by dilatometery. The average linear thermal expansion coefficients (α-bar ) of the compounds decrease on going from EuO 1.5 to DyO 1.5 . The values of α-bar for EuO 1.5 , GdO 1.5 and DyO 1.5 containing solid solutions showed a downward trend as a function of the dopant concentration. The linear thermal expansion (293-1473K) of the solid solutions investigated by high-temperature XRD also showed a similar trend

  19. Facile combustion synthesis of novel CaZrO3:Eu , Gd red phosphor ...

    Indian Academy of Sciences (India)

    red phosphor and remarkably enhanced photoluminescence by Gd. 3+ doping. QINGQING DU1, GUANGJUN ZHOU1,∗. , SHUO ZHANG2, XIAO JIA3, HAIFENG ZHOU1 and ZHONGSEN YANG1. 1State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P R China. 2SEPCO III, Qingdao 266100, P R ...

  20. Dependence of morphology and photoluminescent properties of GdPO4:Eu3+ nanostructures on synthesis condition

    International Nuclear Information System (INIS)

    Yu Lixin; Li Dianchao; Yue Mingxin; Yao Jie; Lu Shaozhe

    2006-01-01

    GdPO 4 :Eu 3+ nanoparticles, nanowires and nanorods phosphors were successfully synthesized by a hydrothermal method. Their photoluminescent properties were investigated and compared. The results indicated that the one-dimensional nanowires and nanorods were formed as the pH value of precursor solution was 1, 5 and 9, while zero-dimensional nanoparticles were formed for the pH value of 9. The crystallization state of nanoparticles was relative lower and the crystal structure belongs to monoclinic phase for other samples. The charge transfer band (CTB) of Eu 3+ ions in nanorods (for pH value of 13) clearly blue-shifted in contrast with other samples. The integrate intensity ratio of 5 D 0 - 7 F 2 to 5 D 0 - 7 F 1 in nanoparticles increased due to high disorder. The lifetime of 5 D 0 level of Eu 3+ in nanoparticles decreased in comparison with other samples and radiative transition rate of 5 D 0 -bar J 7 F J increased

  1. Magnetic and electrical properties of the stannides RE sub 3 Co sub 6 Sn sub 5 (RE Sm, Gd, Tb and Dy)

    CERN Document Server

    Kaczorowski, D; Rogl, P; Romaka, L; Gorelenko, Y

    2003-01-01

    Polycrystalline samples of the ternary intermetallics RE sub 3 Co sub 6 Sn sub 5 (RE Sm, Gd, Tb and Dy) were studied by means of magnetization, dc magnetic susceptibility and electrical resistivity measurements. All these stannides were found to order magnetically at low temperatures. Sm sub 3 Co sub 6 Sn sub 5 is antiferromagnetic below T sub N = 8 K, while Tb sub 3 Co sub 6 Sn sub 5 exhibits ferromagnetic ordering below T sub C = 16 K. The other two compounds show more complex magnetic behaviour with subsequent phase transitions in the ordered regions. For Gd sub 3 Co sub 6 Sn sub 5 one observes the onset of ferromagnetism at T sub C = 25 K, which is followed by a change in the magnetic structure at T sub 1 = 12 K. In the case of Dy sub 3 Co sub 6 Sn sub 5 an antiferromagnetic type of order sets in at T sub N = 7 K, and then a spin structure rearrangement occurs at T sub 1 = 3 K that yields a ferromagnetic component at lower temperatures. All the ternaries studied exhibit metallic-like conductivity with pro...

  2. Bifunctional Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+}nanocomposites obtained by the homogeneous precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Hongxia [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shanxi Key Laboratory of Physico-Inorganic Chemistry, School of Chemistry and Materials Science, Northwest University, Xi’an, Shanxi 710069 (China); Cui, Bin, E-mail: cuibin@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shanxi Key Laboratory of Physico-Inorganic Chemistry, School of Chemistry and Materials Science, Northwest University, Xi’an, Shanxi 710069 (China); Wang, Yingsai [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shanxi Key Laboratory of Physico-Inorganic Chemistry, School of Chemistry and Materials Science, Northwest University, Xi’an, Shanxi 710069 (China)

    2013-05-15

    Graphical abstract: The TEM images reveal clearly the core–shell structures because of the obvious difference in contrast between the central part and the fringe, which indicates the Gd{sub 2}O{sub 3}:Eu{sup 3+} layer had successfully deposited on the magnetite Fe{sub 3}O{sub 4} cores. And Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+} nanoparticles keep the spherical morphology, non-aggregation and rough surface. The images reveal that the average diameters of the Fe{sub 3}O{sub 4} and Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+} nanoparticles are ∼200 nm and ∼250 nm, respectively. The thickness of Gd{sub 2}O{sub 3}:Eu{sup 3+} layer is ∼25 nm. Highlights: ► Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+} nanocomposites were synthesized by homogeneous precipitation method. ► Formation of core–shell nanostructure revealed by transmission electron microscopy. ► Fe{sub 3}O{sub 4}@Gd{sub 2}O{sub 3}:Eu{sup 3+} nanocomposites showed magnetic behavior and fluorescence properties. ► Possible applications including bioseparation, drug delivery system, bio-labels, etc. - Abstract: An easy homogeneous precipitation method was developed for the synthesis of bifunctional magnetic-fluorescent nanocomposites with Fe{sub 3}O{sub 4} nanoparticles as the core and europium-doped gadolinium oxide (Gd{sub 2}O{sub 3}:Eu{sup 3+}) as the shell. The nanocomposites showed both strong magnetic behavior and unique Eu-related fluorescence properties with a high emission intensity, which may lead to development of nanocomposites with great potential for applications in drug targeting, biosensors, and diagnostic analysis.

  3. Symmetry-Breaking Transitions in RECuAs2-xPx (RE=Sm, Gd, Ho, and Er)

    Energy Technology Data Exchange (ETDEWEB)

    Mozharivskyj, Yurij [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Structural changes resulting in lower symmetries can be understood in terms of electronic instabilities and Coulomb interactions. The interplay of these two interrelated factors is complicated and difficult to analyze. The RECuAs2-xP x phases, because of the variation in the chemical content (As/P substitution), allow, with the aid of band structures, Madelung energies and Landau theory, a partial unraveling of the forces important in the symmetry-breaking transitions in RECuAs2-xP x (RE = Sm, Gd, Ho and Er). Distortions of the P layers in SmCu1.15P2, GdCuP2.20 and ErCuP2 are usefully thought of as generalized Peierls distortions, i.e., they lower the electronic (and total) energy and lead to more stable structures. On the other hand, the P4/nmm → Pmmn transitions, which are observed in all studied arsenophosphide series and occur upon substitution of P for As, originate from the B1g vibrational mode and are structural adaptations to smaller P atoms. These transitions provide tighter atomic packing and better Coulomb interactions. Configurational contribution to the entropy becomes important in stabilizing the mixed occupancy in the RECuAs 2-xP x arsenophosphides. While geometric and electronic factors favor separation of the As and P atoms over two different crystallographic sites, configurational entropy stabilizes the As/P mixing on these two sites.;Progress in the research on RECuAs2-xP x was dependent upon the ability of Landau theory to predict, explain and dismiss structural models and transitions. The space group Pmmn (arising from the B 1g vibrational mode) in all mixed arsenophosphides and the existence of these mixed arsenophosphides followed from the analysis of GdCuAs 2 and GdCuP2, using Landau theory. The impossibility of obtaining the high-symmetry structure (P4/nmm) and the low symmetry structure

  4. First-principles calculation of structural and energetic properties for A2Ti2O7 (A = Lu, Er, Y, Gd, Sm, Nd, La)

    International Nuclear Information System (INIS)

    Zhang, Z.L.; Xiao, H.Y.; Zu, Xiaotao T.; Gao, Fei; Weber, William J.

    2009-01-01

    A first-principles method has been employed to investigate the structural and energetic properties for A2Ti2O7 (A = Lu, Er, Y, Gd, Sm, Nd, La), including the formation energies of the cation antisite-pair, the anion Frenkel pair that defines anion-disorder, and the coupled cation antisite-pair/anion-Frenkel. It is proposed that the interaction may have more significant influence on the radiation resistance behavior of titanate pyrochlores, although the interactions are relatively much stronger than the interactions. It is found that the defect formation energies are not simple functions of the A-site cation radii. The formation energy of the cation antisite-pair increases continuously as the A-site cation varies from Lu to Gd, and then decreases continuously with the variation of the A-site cation from Gd to La, in excellent agreement with the radiation-resistance trend of the titanate pyrochlores. The band gaps in these pyrochlores were also measured, and the band gap widths changed continuously with cation radius.

  5. Electric and magnetic properties of Al{sub 86}Ni{sub 8}R{sub 6} (R=Sm, Gd, Ho) alloys in liquid and amorphous states

    Energy Technology Data Exchange (ETDEWEB)

    Sidorov, V. [Ural State Pedagogical University, Ekaterinburg (Russian Federation); Ural Federal University, Ekaterinburg (Russian Federation); Svec, P.; Svec, P.; Janickovic, D. [Institute of Physics SAS, Bratislava (Slovakia); Mikhailov, V. [Ural State Pedagogical University, Ekaterinburg (Russian Federation); Sidorova, E. [Plekhanov Russian University of Economics, Moscow (Russian Federation); Son, L. [Ural State Pedagogical University, Ekaterinburg (Russian Federation); Ural Federal University, Ekaterinburg (Russian Federation)

    2016-06-15

    Electrical resistivity and magnetic susceptibility of Al{sub 86}Ni{sub 8}Sm{sub 6}, Al{sub 86}Ni{sub 8}Gd{sub 6} and Al{sub 86}Ni{sub 8}Ho{sub 6} alloys are studied in a wide temperature range including amorphous, crystalline and liquid states. The negative value of resistivity temperature coefficient in amorphous ribbons is explained by the structural separation starting much before the beginning of their crystallization. The effective magnetic moments per Gd and Ho atoms are found to be essentially lower than for R{sup 3+} ions. The results are discussed in supposition of directed bonds between rare earth and aluminum atoms. - Highlights: • Electric and magnetic properties of Al{sub 86}Ni{sub 8}R{sub 6} alloys are studied experimentally. • The negative value of rtc in amorphous ribbons is explained. • The effective magnetic moments per Gd and Ho are found to be lower than for R{sup 3+} ions.

  6. Multifunctional MWCNTs-NaGdF4:Yb(3+),Er(3+),Eu(3+) hybrid nanocomposites with potential dual-mode luminescence, magnetism and photothermal properties.

    Science.gov (United States)

    Liu, Wenjia; Liu, Guixia; Dong, Xiangting; Wang, Jinxian; Yu, Wensheng

    2015-09-21

    A novel dual-mode luminescence multifunctional hybrid nanomaterial has been successfully prepared by coating the NaGdF4:Yb(3+),Er(3+),Eu(3+) nanoparticles (NPs) on the surface of MWCNTs. The as-synthesized MWCNTs-NaGdF4:Yb(3+),Er(3+),Eu(3+) nanocomposites (NCs) can simultaneously take advantage of both magnetic and optical properties of NaGdF4:Yb(3+),Er(3+),Eu(3+) NPs and the photothermal conversion property of MWCNTs. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), vibrating sample magnetometry (VSM), UV-Vis absorption, luminescence spectroscopy and fluorescence lifetime measurements. Meanwhile, the photothermal conversion was examined under irradiation with a 980 nm laser. The results show that the MWCNTs-NaGdF4:Yb(3+),Er(3+),Eu(3+) NCs have preferably magnetic, dual-mode (up- and down-conversion) luminescence and photothermal properties. And the NCs have good biocompatibility, low toxicity and up-conversion luminescence for cell imaging. As a consequence, the dual-mode luminescence multifunctional nanomaterials have potential applications in environmental science fields and clinical fields for magnetic resonance imaging, fluorescence imaging, photothermal therapy, bioseparation and targeted drug delivery.

  7. An Experimental Study of Eu/Gd Partitioning Between a Shergottite Melt and Pigeonite: Implications for the Oxygen Fugacity of the Martian Interior

    Science.gov (United States)

    McCanta, M. C.; Rutherford, M. J.; Jones, J. H.

    2002-01-01

    We experimentally investigated the partitioning behavior of Eu/Gd between a synthetic shergottite melt and pigeonite as a function of oxygen fugacity. This has implications for the oxidation state of the source region of the martian meteorites. Additional information is contained in the original extended abstract.

  8. Study of the influence of the codopant over the photoluminescent properties of PAA doped with Eu3+, Gd3+, and Tb3+

    International Nuclear Information System (INIS)

    Flores, M.; Arroyo, R.

    2003-01-01

    The results are presented obtained about the synthesis of acrylic poly acid characterization (PAA) doped with Eu 3+ , Gd 3+ and Tb 3+ . They got ready materials with even of these ions and it was studied the influence of the co dopant in the processes of emission of Eu 3+ (λ em = 618 nm), Gd 3+ (λ em = 624 nm) and Tb 3+ (λ em = 546 nm), as well as their effect in the phosphorescence (λ em = 450 nm) of the polymeric matrix. It was found that the intensity of the emission of Eu 3+ diminishes substantially due to the presence of the ions Gd 3+ , contrary to what happens when the co dopant is Tb 3+ , which causes an increase. In the one case of the emission of Tb 3+ , this it increases with the presence of Gd 3+ but it diminishes when Eu 3+ is present. These results are consequence of the homogeneous distribution of those dopants and of the phenomena of energy transfer that happen in the materials synthesized. (Author)

  9. Tune color of single-phase LiGd(MoO4)2-X(WO4)X: Sm3+, Tb3+ via adjusting the proportion of matrix and energy transfer to create white-light phosphor

    Science.gov (United States)

    Wu, Hongyue; Yang, Junfeng; Wang, Xiaoxue; Gan, Shucai; Li, Linlin

    2018-03-01

    A series of LiGd(MO4)2: Sm3+, Tb3+ (M = Mo, W) phosphors was prepared by a conventional solid state reaction method. Powder X-Ray diffraction (XRD) analysis reveals that the compounds are of the same structure type. Their luminescent properties have been studied. The optimal doping concentrations are 8% for Sm3+ and 18% for Tb3+ in the LiGd(MoO4)2 host. Sm3+ and Tb3+ have different sensitivity to the Mo/W ratio. For LiGd(MoO4)2-X(WO4)X: Sm3+ (X = 0, 0.4, 0.8, 1.2, 1.6, 2.0), the strongest emission intensity is 1.766 times than that of the weakest, while 171 times for LiGd(MoO4)2-X(WO4)X: Tb3+. The experimental results show that Mo/W ratio strong influences on the properties of LiGd(MoO4)2-X(WO4)X: Tb3+. With the increasing of WO42- groups concentration, the shape of characteristic excitation peaks of Tb3+ is almost the same and the excitation intensity gradually increase. Moreover, the energy transfer from Tb3+ to Sm3+ has been realized in the co-doped phosphors. The experimental analysis and theoretical calculations reveal that the quadrupole-quadrupole interaction is the dominant mechanism for the Tb3+→Sm3+ energy transfer. Therefore, luminous intensity can be adjusted by different sensitivities to matrix composition and energy transfer from Tb3+→Sm3+. By this tuning color method, white-light-emitting phosphor has been prepared. The excitation wavelength is 378 nm, and this indicates that the white-light-emitting phosphor could be pumped by near-UV light.

  10. Preparation, Characterization, and Ionic Transport Properties of Nanoscale Ln2Zr2O7 (Ln = Ce, Pr, Nd, Sm, Gd, Dy, Er, and Yb) Energy Materials

    Science.gov (United States)

    Solomon, Sam; George, Aneesh; Thomas, Jijimon Kumpakkattu; John, Annamma

    2015-01-01

    Nanoparticles of lanthanide (Ln)-based zirconates have been prepared through the autoignited combustion technique. The structure of the system was analyzed by powder x-ray diffraction and vibrational spectroscopic tools. The compounds with Ln = Ce, Pr, Nd, Sm, and Gd have pyrochlore cubic structure, whereas those with Ln = Dy, Er, and Yb possess anion-deficient disordered cubic fluorite structure. The optical properties of the powder were analyzed using ultraviolet-visible spectroscopy. Pellets of the compounds were sintered in the range from 1325°C to 1530°C for 2 h. The surface morphology of sintered Nd2Zr2O7 was analyzed by scanning electron microscopy. Impedance spectroscopic studies of the samples were carried out at different temperatures. The conductivity increased to the order of 10-2 S/m at 750°C, and the highest conductivity of 13.21 × 10-2 S/m was obtained for Er2Zr2O7. All samples of this system are suitable candidates for fabrication of electrolytes for use in solid oxide fuel cells, particularly at moderate temperatures.

  11. Emission channeling experiments from the decay of $^{149}$Gd to $^{149}$Eu in GaN

    CERN Document Server

    De Vries, B; Vantomme, A; Correia, J G

    2003-01-01

    The lattice site location of excited states of $^{149}$Eu was studied by means of the emission channeling technique. 60 keV implantation of $^{149}$Tb into a GaN thin film was performed at room temperature up to a dose of 2.0 $\\times 10^{13}$ cm$^{-2}$. This radioactive isotope eventually decays into short-lived excited states of $^{149}$Eu. The conversion electrons emitted in the subsequent decay to the $^{149}$Eu ground state were detected with a position sensitive detector. We measured their angular distributions around the [0001], [1102], [1101] and [2113] axes in the as-implanted state and after 600°C and 900°C vacuum annealing. Already in the as-implanted state around 65% of $^{149^{*}}$Eu atoms were found on substitutional Ga sites. The root mean square (rms) displacements from the substitutional sites in the as-implanted state were found to be around 0.13-0.16 . Annealing up to 600$^\\circ$C increased the substitutional fraction by a few percent and slightly reduced the rms displacements, most likely...

  12. Energy transfer processes in K{sub 5}Li{sub 2}GdF{sub 10}:Eu,Pr

    Energy Technology Data Exchange (ETDEWEB)

    Solarz, P. [Institute of Low Temperature and Structure Research, Polich Academy of Sciences, ul. Okolna 2, PL-50422 Wroclaw (Poland)], E-mail: solarz@int.pan.wroc.pl; Ryba-Romanowski, W. [Institute of Low Temperature and Structure Research, Polich Academy of Sciences, ul. Okolna 2, PL-50422 Wroclaw (Poland)

    2007-04-15

    In K{sub 5}Li{sub 2}Gd{sub 0.80}Pr{sub 0.10}Eu{sub 0.10}F{sub 10} the {sup 5}D{sub 1,0} luminescence of europium is quenched by the presence of Pr{sup 3+}. Analysis of the decay curves of the {sup 5}D{sub 0} and {sup 5}D{sub 1} luminescence, recorded at room temperature, suggests that the Eu{sup 3+5}D{sub 0} emission is quenched by quadrupole-quadrupole interaction with {sup 1}D{sub 2} multiplet of praseodymium. The generalized Yokota-Tanimoto model has been used to explain the behavior of the decay curves and to determine the kinetic microparameters C{sub DA}, related to the cross relaxation, and D, related to the energy migration probabilities. The 'critical radius'(R{sub 0}) for these interaction was calculated to be in the range 10.007-11.528 A.

  13. The temperature-sensitive luminescence of (Y,Gd)VO4:Bi3+,Eu3+ and its application for stealth anti-counterfeiting

    International Nuclear Information System (INIS)

    Chen, Lei; Zhang, Yao; Luo, Anqi; Liu, Fayong; Jiang, Yang; Hu, Qingzhuo; Chen, Shifu; Liu, Ru-Shi

    2012-01-01

    Anti-counterfeiting technologies are desired to protect products far away from the violation of dummy, fake and shoddy goods. The phosphor of (Y,Gd)VO 4 :Bi 3+ ,Eu 3+ was synthesized for the application of this purpose. Its photoluminescence was investigated by exciting with different wavelengths at variant temperatures. Wide emission color ranged from green through yellow to orange was tuned up by tailor-ing Bi 3+ and Eu 3+ concentrations. The temperature dependent luminescence and wavelength selective excitation of (Y,Gd)VO 4 :Bi 3+ ,Eu 3+ were observed, which provide different encryptions in anti-counterfeiting. To verify the feasibility in application, two anti-counterfeiting patterns were fabricated practically and excellent performance was obtained. Moreover, the physical mechanisms for the different phenomena of luminescence were elucidated from excitation spectra combining with the configuration coordinate model. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Investigation of the imaging characteristics of the Gd{sub 2}O{sub 3}:Eu nanophosphor for high-resolution digital X-ray imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So-yeong [Radiation Image Laboratory, Inje University, Gimhae (Korea, Republic of); Park, Ji-koon [R and D Center of LISTEM, Seoul (Korea, Republic of); Kang, Sang-sik [Gimhae Biomedical Industry Supporting Center, Gimhae (Korea, Republic of); Cha, Byung-youl [Radiation Image Laboratory, Inje University, Gimhae (Korea, Republic of); Cho, Sung-ho [Radiation Image Laboratory, Inje University, Gimhae (Korea, Republic of); Shin, Jung-wook [Radiation Image Laboratory, Inje University, Gimhae (Korea, Republic of); Son, Dae-woong [Radiation Image Laboratory, Inje University, Gimhae (Korea, Republic of); Nam, Sang-hee [Medical Imaging Research Center, Inje University, Gimhae (Korea, Republic of)]. E-mail: nsh@bme.inje.ac.kr

    2007-06-11

    For possible applications in high-resolution medical image systems, we manufactured a Eu{sup 3+}-doped Gd{sub 2}O{sub 3} nanophosphor using the low-temperature solution combustion method, and evaluated its performance as an image sensor. The structural and optical characteristics of the fabricated nanophosphor were investigated using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), photoluminescence spectrum (PL), and luminescence decay time measurements. From the FE-SEM and XRD results, we established that the fabricated nanophosphor was formed of spherical particles of about 30-40 nm, and confirmed that the particles agglomerated as the sintering temperature increases. From PL spectra, a strong peak appeared near 611 nm, and the luminescent intensity was seen to be affected by the doping concentration of Eu. Gd{sub 2}O{sub 3}:Eu nanophosphor particles have shown the highest luminescent efficiency at a Eu concentration of 5 wt%. In the luminescent decay time measurements, the mean decay time was about 2.3-2.6 ms, about two times longer than that of the general bulk phosphor, and affected by the of Eu-doping concentration. For the investigation of the imaging characteristics of the fabricated nanophosphor, we connected the Gd{sub 2}O{sub 3}:Eu nanophosphor film to a commercial CMOS image sensor, obtained the X-ray images and evaluated the modulation transfer function (MTF) as a function of the Eu concentration. We were able to obtain high-resolution X-ray images and found that the Eu concentration also influenced the imaging characteristics.

  15. On the extended series of quaternary Zintl phases Ca{sub 13}REMnSb{sub 11} (RE = La-Nd, Sm, Gd-Dy)

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Jai; Stoyko, Stanislav; Voss, Leonard; Bobev, Svilen [Department of Chemistry and Biochemistry, University of Delaware, 19716, Newark, DE (United States)

    2016-06-15

    Eight new compounds with a general formula Ca{sub 14-x}RE{sub x}MnSb{sub 11} (RE = La-Nd, Sm, Gd-Dy; x ∼ 1) were synthesized by the molten flux method and their structures were established via single-crystal X-ray diffraction. The overarching goal of this study was to investigate the effect of electron doping, via substitution of RE{sup 3+} at Ca{sup 2+} sites, on the crystal structure and physical properties of Ca{sub 14}MnSb{sub 11}, which is a candidate for thermoelectric applications. All studied phases are isostructural, and crystallize in the tetragonal body-centered space group I4{sub 1}/acd (Ca{sub 14}AlSb{sub 11} structure type, Pearson index tI208). The structure is made up of MnSb{sub 4}{sup 10-} tetrahedra, randomly mixed Ca{sup 2+} and RE{sup 3+} cations, Sb{sup 3-} anions, and linear Sb{sub 3}{sup 7-} polyanions. Comprehensive structural work confirms high rare-earth metal content with Ca{sup 2+}/RE{sup 3+} randomly mixed on all four cation sites, with the caveat that the larger RE atoms (La-Nd) prefer to occupy the Ca2 site, while the smaller RE atoms (Sm, Gd, Tb, and Dy) preferably occupy the Ca1 site. Nearly phase-pure polycrystalline samples have been synthesized using solid-state reactions, and have been used for physical property measurements. The resistivities of the bulk Ca{sub 14-x}RE{sub x}MnSb{sub 11} (RE = La-Nd, Sm, Gd; x ∼ 1) samples reveal semiconducting behavior, consistent with the notion of electron doping in the parent p-type Ca{sub 14}MnSb{sub 11} material. Magnetic susceptibilities suggest complex magnetic ordering at temperatures below ca. 50 K, likely originating from coupling between two or more magnetic sub-lattices. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Spectral and CIE parameters of red emitting Gd3Ga5O12:Eu3+ phosphor

    International Nuclear Information System (INIS)

    Sharma, S.K.; Som, S.; Jain, R.; Kunti, A.K.

    2015-01-01

    This paper reports the structural, spectral and photometric parameters of Eu 3+ doped gadolinium gallium garnet (GGG) phosphor synthesized by combustion synthesis method and post annealed at three different temperatures. The XRD studies show the lattice formation of GGG phosphor with body centered cubic structure. Rietveld refinement and analytical calculation of different structural parameters were performed to get the idea about the rare earth substitution in host matrix. The band gap of the phosphor was calculated from diffuse reflectance spectra using the Kubelka–Munk function. The characteristic red luminescence corresponding to 5 D 0 → 7 F J (J=1, 2) transitions of Eu 3+ was observed after irradiation with UV light. The various analytical parameters such as Judd–Ofelt intensity, spectral and CIE were estimated from the photoluminescence data. - Highlights: • Rietveld refinement result indicates the rare earth substitution in host matrix. • Spectroscopic investigation of Eu 3+ in gadolinium gallium garnet host. • CIE parameters and purity indicate its suitability in lighting technology

  17. Engineering of Highly Susceptible Paramagnetic Nanostructures of Gd2S3:Eu3+: Potentially an Efficient Material for Room Temperature Gas Sensing Applications

    Directory of Open Access Journals (Sweden)

    Muhammed M. Radhi

    2010-11-01

    Full Text Available This research papers throws light into the compositional, morphological and structural properties of novel nanoparticles of Gd2S3:Eu3+ synthesized by a simple co-precipitation technique. Furthermore, we also prognosticate that this material could be useful for gas sensing applications at room temperature. Nanostructures formulation by this method resulted in the formation of orthorhombic crystal structure with primitive lattice having space group Pnma. The material characterizations are performed using X-ray diffraction (XRD, energy dispersive X-ray analysis (EDX, thermo-gravimetric analysis/differential thermal analysis (TGA/DTA and transmission electron microscope (TEM. The calculated crystallite sizes are ~ 2-5 nm and are in well accordance with the HRTEM results. EDX result confirms the presence and homogeneous distribution of Gd and Eu throughout the nanoparticle. The prepared nanoparticles exhibit strong paramagnetic nature with paramagnetic term, susceptibility c = 8.2 ´ 10-5 emg/g Gauss. TGA/DTA analysis shows 27 % weight loss with rise in temperature. The gas sensing capability of the prepared Gd2S3:Eu3+ magnetic nanoparticles are investigated using the amperometric method. These nanoparticles show good I-V characteristics with ideal semiconducting nature at room temperature with and without ammonia dose. The observed room temperature sensitivity with increasing dose of ammonia indicates applicability of Gd2S3 nanoparticles as room temperature ammonia sensors.

  18. Designing of luminescent GdPO4:Eu@LaPO4@SiO2 core/shell nanorods: Synthesis, structural and luminescence properties

    Science.gov (United States)

    Ansari, Anees A.; Labis, Joselito P.; Aslam Manthrammel, M.

    2017-09-01

    GdPO4:Eu3+ (core) and GdPO4:Eu@LaPO4 (core/shell) nanorods (NRs) were successfully prepared by urea based co-precipitation process at ambient conditions which was followed by coating with amorphous silica shell via the sol-gel chemical route. The role of surface coating on the crystal structure, crystallinity, morphology, solubility, surface chemistry and luminescence properties were well investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, Fourier Transform Infrared (FTIR), UV-Vis, and photoluminescence spectroscopy. XRD pattern revealed highly purified, well-crystalline, single phase-hexagonal-rhabdophane structure of GdPO4 crystal. The TEM micrographs exhibited highly crystalline and narrow size distributed rod-shaped GdPO4:Eu3+ nanostructures with average width 14-16 nm and typical length 190-220 nm. FTIR spectra revealed characteristic infrared absorption bands of amorphous silica. High absorbance in a visible region of silica modified core/shell/Si NRs in aqueous environment suggests the high solubility along with colloidal stability. The photoluminescence properties were remarkably enhanced after growth of undoped LaPO4 layers due to the reduction of nonradiative transition rate. The advantages of presented high emission intensity and high solubility of core/shell and core/shell/Si NRs indicated the potential applications in monitoring biological events.

  19. Noticeable red emission and Raman active modes in nanoscale gadolinium oxyfluoride (Gd4O3F6) systems with Eu3+ inclusion

    International Nuclear Information System (INIS)

    Hazarika, Samiran; Mohanta, Dambarudhar

    2017-01-01

    Eu 3+ doped gadolinium oxyfluoride (Gd 4 O 3 F 6 , GOF) nanoscale systems have been synthesized following a modified Pechini method. While exhibiting a tetragonal crystal structure, the GOF nanosystem gave an average crystallite size (d) of ∝21-26 nm. The Lotgering factor (L F ), which is a measure of orientation of crystallites along the preferred direction was found to vary between 0.22 and 0.48. In the photoluminescence spectra, ∝595 and ∝613 nm peaks were identified as magnetically driven ( 5 D 0 → 7 F 1 ) and electrically driven ( 5 D 0 → 7 F 2 ) transitions with latter (red emission) being strongly manifested with Eu 3+ doping concentration and intrinsic defects. Moreover, several Raman active modes have been probed in the Raman spectra with low frequency peaks (<300 cm -1 ) and moderate frequency peaks (∝481 and 567 cm -1 ) assigned to observable vibration of heavy atom Gd-Gd pairs and Gd-O groups, respectively. Apart from manifestation of phononic features, inclusion of Eu 3+ in the host lattice would bring new insight on improving the red emission response prior to concentration quenching. (orig.)

  20. Magnetic properties of A0.6Pb0.4MnO3 perovskites (A=Nd,Sm,Gd)

    International Nuclear Information System (INIS)

    Derkachenko, V.N.; Troyanchuk, I.O.; Pastushonok, S.N.

    1991-01-01

    Crystal structure and magnetic properties of A 0.6 Pb 0.4 MnO 3 perovskite is found to be a ferromagnetic material (T c =180 K). The compound unit cell is distorted rhombohedrally. The Sm perovskite is distinguished by a 0 1 -orthorhombic distortion of the unit cell and is an inhomogeneous ferromagnetic below 90 K. The 0'1-orthorhombic distortion is inherent also in the Gd perovskite unit cell. Below 40 K one can observe magnetic properties typical of spin glasses. Transition of a 'frozen' state is realized by locking gradually the magnetic moments of the ferromagnetic clusters. As the REI radius decreases, the perovskite crystal structure is distorted becouse of mismatch between ionic radii of REI and manganese. The Jahn-Teller dynamic effect becomes static, promoting a change in the mechnism of exchange interactions

  1. Platinum triangles in the Pt/Al framework of the intermetallic REPt{sub 6}Al{sub 3} (RE = Ce-Nd, Sm, Gd, Tb) series

    Energy Technology Data Exchange (ETDEWEB)

    Eustermann, Fabian; Stegemann, Frank; Renner, Konstantin [Institut fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Universitaet Muenster (Germany); Janka, Oliver [Institut fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Universitaet Muenster (Germany); Institut fuer Chemie, Carl von Ossietzky Universitaet Oldenburg (Germany)

    2017-12-13

    The compounds of the REPt{sub 6}Al{sub 3} series (RE = Ce-Nd, Sm, Gd, Tb) were obtained by reaction of the elements via arc-melting. They were characterized by powder and single-crystal X-ray diffraction (NdPt{sub 6}Al{sub 3}: wR = 0.0432, 759 F{sup 2} values, 33 variables) as well as by magnetic susceptibility measurements. The isostructural compounds crystallize with a new structure type in the trigonal crystal system with space group R anti 3c, twelve formula units in the unit cell, and lattice parameters of a = 752-755 and c = 3882-3945 pm. The crystal structure can be described by different slabs stacked along [001]. One layer features Pt{sub 3} triangles, centering the cavities of a flat honeycomb RE layer that are arranged in a..ABCA{sup '}B{sup '}C{sup '}.. sequence. The other layer consists of condensed hexagonal [Pt{sub 6}Al{sub 6}] prisms, centered by Pt atoms, separating the before mentioned slabs. Magnetic measurements revealed that all rare-earth atoms are in the trivalent oxidation state, however, due to the low lanthanoide content magnetic ordering phenomena were observed only at low temperatures [SmPt{sub 6}Al{sub 3}: T{sub C} = 5.0(1) K; GdPt{sub 6}Al{sub 3}: T{sub C} = 7.3(1) K; TbPt{sub 6}Al{sub 3}: T{sub N} = 3.6(1) K]. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Magnetic properties of quadruple perovskites Ba4LnRu3O12 (Ln=La, Nd, Sm-Gd, Dy-Lu)

    International Nuclear Information System (INIS)

    Shimoda, Yuki; Doi, Yoshihiro; Wakeshima, Makoto; Hinatsu, Yukio

    2010-01-01

    Quadruple perovskites Ba 4 LnRu 3 O 12 (Ln=La, Nd, Sm-Gd, Dy-Lu) were prepared and their magnetic properties were investigated. They adopt the 12L-perovskite-type structure consisting of Ru 3 O 12 trimers and LnO 6 octahedra. All of these compounds show an antiferromagnetic transition at 2.5-30 K. For Ba 4 NdRu 3 O 12 , ferrimagnetic ordering has been observed at 11.5 K. The observed magnetic transition is due to the magnetic behavior of the Ru 4.33+ 3 O 12 trimer with S=1/2 . Magnetic properties of Ba 4 LnRu 3 O 12 were compared with those of triple perovskites Ba 3 LnRu 2 O 9 and double perovskites Ba 2 LnRuO 6 . - Graphical abstract: Quadruple perovskites Ba 4 LnRu 3 O 12 (Ln=La, Nd, Sm-Gd, Dy-Lu) were prepared. They adopt the 12L-perovskite-type structure consisting of Ru 3 O 12 trimers and LnO 6 octahedra. All of these compounds show an antiferromagnetic transition at 2.5-30 K. For Ba 4 NdRu 3 O 12 , ferrimagnetic ordering has been observed at 11.5 K. The observed magnetic transition is due to the magnetic behavior of the Ru 4.33+ 3 O 12 trimer with S=1/2 . Magnetic properties of Ba 4 LnRu 3 O 12 were compared with those of triple perovskites Ba 3 LnRu 2 O 9 and double perovskites Ba 2 LnRuO 6 .

  3. Ln28Ti2O7 (Ln = La, Nd, Sm, Gd): a novel series of defective Ruddlesden–Popper phases formed by topotactic dehydration of HLnTiO4

    OpenAIRE

    Thangadurai, V; Subbanna, GN; Gopalakrishnan, J

    1998-01-01

    Topotactic dehydration of HLnTiO4 (Ln = La, Nd, Sm or Gd) around 480–500 °C yields a new series of metastable layered perovskite oxides, Ln28Ti2O7, that possess a defective Sr3Ti2O7 structure, where the cubooctahedral sites within the double-perovskite layers are most likely vacant.

  4. Controlled processing of (Gd,Ln2O3:Eu (Ln = Y, Lu red phosphor particles and compositional effects on photoluminescence

    Directory of Open Access Journals (Sweden)

    Bin Lu

    2013-11-01

    Full Text Available Synthesis of (Gd0.95−xLnxEu0.052O3 (Ln = Y and Lu, x = 0–0.95 powders via ammonium hydrogen carbonate (AHC precipitation has been systematically studied. The best synthesis parameters are found to be an AHC/total cation molar ratio of 4.5 and an ageing time of 3 h. The effects of Y3+ and Lu3+ substitution for Gd3+, on the nucleation kinetics of the precursors and structural features and optical properties of the oxides, have been investigated. The results show that (i different nucleation kinetics exist in the Gd–Y–Eu and Gd–Lu–Eu ternary systems, which lead to various morphologies and particle sizes of the precipitated precursors. The (Gd,Y2O3:Eu precursors display spherical particle morphologies and the particle sizes increase along with more Y3+ addition. The (Gd,Lu2O3:Eu precursors, on the other hand, are hollow spheres and the particle sizes increase with increasing Lu3+ incorporation, (ii the resultant oxide powders are ultrafine, narrow in size distribution, well dispersed and rounded in particle shape, (iii lattice parameters of the two kinds of oxide solid solutions linearly decrease at a higher Y3+ or Lu3+ content. Their theoretical densities linearly decrease with increasing Y3+ incorporation, but increase along with more Lu3+ addition and (iv the two kinds of phosphors exhibit typical red emissions at ~613 nm and their charge-transfer bands blue shift at a higher Y3+ or Lu3+ content. Photoluminescence/photoluminescence excitation intensities and external quantum efficiency are found to decrease with increasing value of x, and the fluorescence lifetime mainly depends on the specific surface areas of the powders.

  5. Preparation and optimization of ceramic neutron image plates based on BaFBr : Eu2+ and GdF3

    Science.gov (United States)

    Kolb, R.; Zimmermann, J.; Schlapp, M.; Hesse, S.; von Seggern, H.

    2005-09-01

    Commercially available neutron image plates (NIPs) consist of a mixture of a powdered x-ray storage phosphor and a neutron converter, both embedded in an organic binder supported on a polymer sheet. The initiation of the storage mechanism in the phosphor is caused by conversion electrons generated in the neutron converter due to neutron absorption and activation and its subsequent decay. The organic binder phase just provides mechanical stability to the NIP but reduces its efficiency through two effects: first by the absorption of low energy electrons and second by introducing an inactive volume fraction to the layer. Avoiding the organic fraction, for example by preparing a ceramic NIP without binder, could increase the efficiency and spatial resolution without a loss in mechanical stability. In the following, two processes for preparation of ceramic NIPs are reported, both delivering ceramic NIPs consisting solely of GdF3, as the neutron converter and BaFBr : Eu2+, as the storage phosphor. The correlation between the sintering parameters and volume fraction of the neutron converter is investigated with respect to high efficiency and high spatial resolution. The generally observed antidromic behaviour between these two quantities was observed in this study also.

  6. Study of the influence of the codopant over the photoluminescent properties of PAA doped with Eu{sup 3+}, Gd{sup 3+}, and Tb{sup 3+}; Estudio de la influencia del codopante sobre las propiedades fotoluminiscentes de PAA dopado con Eu{sup 3+}, Gd{sup 3+} y Tb{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Flores, M.; Arroyo, R. [Departamento de Fisica, UAM-I, A.P. 55-534, 09820 Mexico D.F. (Mexico)

    2003-07-01

    The results are presented obtained about the synthesis of acrylic poly acid characterization (PAA) doped with Eu{sup 3+}, Gd{sup 3+} and Tb{sup 3+}. They got ready materials with even of these ions and it was studied the influence of the co dopant in the processes of emission of Eu{sup 3+} ({lambda}{sub em} = 618 nm), Gd{sup 3+} ({lambda}{sub em} = 624 nm) and Tb{sup 3+} ({lambda}{sub em} = 546 nm), as well as their effect in the phosphorescence ({lambda}{sub em} = 450 nm) of the polymeric matrix. It was found that the intensity of the emission of Eu{sup 3+} diminishes substantially due to the presence of the ions Gd{sup 3+}, contrary to what happens when the co dopant is Tb{sup 3+} , which causes an increase. In the one case of the emission of Tb{sup 3+}, this it increases with the presence of Gd{sup 3+} but it diminishes when Eu{sup 3+} is present. These results are consequence of the homogeneous distribution of those dopants and of the phenomena of energy transfer that happen in the materials synthesized. (Author)

  7. Al-Sm-Eu-Sr systematics of eucrites and moon rocks Implications for planetary bulk compositions

    Science.gov (United States)

    Warren, P. H.

    1983-01-01

    Constraints are placed on the bulk compositions of the eucrite parent body (EPB) and the moon through analysis of the Eu and Sr 'anomalies' of eucrites and lunar rooks. It is noted that the elements Al, REE, and Sr are incompatible with the major minerals of these small, low-f(O2) bodies,except for plagioclase. Predictions can be derived about the concentrations of Al, REE, and Sr in samples affected by plagioclase fractionation, based on the hypothesis that these elements in the EPB and moon are all in proportions close to those in the bulk solar system. It is determined that the predictions are almost idealy fulfilled by eucrites and lunar samples. For the EPB, the ratios REE/Al, Sr/Al, and Sr/REE are found to be constrained probably within 10 percent of the chondritic ratios. For the moon, the constraints are found to be less precise: REE/Al is very probably within 25 percent of chondritic; Sr/Al and Sr/REE are probably within 35 percent of chondritic; Sr/Al and Sr/REE are probably within 35 percent of chondritic. It is concluded that there is a very strong similarity between the bulk compositions of the planets and the compositions of chondritic meteorites.

  8. Spin dynamics and structural phase transitions in quasi-2D R sub 2 CuO sub 4 (R=Pr, Sm and Eu) antiferromagnetics

    CERN Document Server

    Golovenchits, E I

    2001-01-01

    One studied spin dynamics and dynamics of lattice in R sub 2 CuO sub 4 (R = Pr, Sm, and Eu) crystals within 20-250 GHz frequency range and within 50350 K temperature interval. One detected abrupt variation of absorption coefficient within wide range of frequencies above 120 GHz at 20, 80 and 150 K temperatures in R sub 2 CuO sub 4 (R = Pr, Sm, and Eu), respectively. Absorption jumpings result from structural phase transitions. Wide ranges of spin-wave excitations were observed in all examined crystals in high-temperature phase. Close to temperatures of phase transitions within wide range of frequencies including frequencies corresponding to ranges of spin-wave excitations one observed lines of a absorption caused by lattice dynamics

  9. Tunable emission and excited state absorption induced optical limiting in Tb2(MoO4)3: Sm3+/Eu3+ nanophosphors

    Science.gov (United States)

    Mani, Kamal P.; Sreekanth, Perumbilavil; Vimal, G.; Biju, P. R.; Unnikrishnan, N. V.; Ittyachen, M. A.; Philip, Reji; Joseph, Cyriac

    2016-12-01

    Photoluminescence properties and optical limiting behavior of pure and Sm3+/Eu3+ doped Tb2(MoO4)3 nanophosphors are investigated. The prepared nanophosphors exhibit excellent emission when excited by UV light. Color-tunable emissions in Tb2-xSmx(MoO4)3 and Tb2-xEux(MoO4)3 are realized by employing different excitation wavelengths or by controlling the doping concentration of Sm3+ and Eu3+. Luminescence quantum yield and CIE chromatic coordinates of the prepared phosphors were also presented. Optical limiting properties of the samples are investigated by open aperture Z-scan technique using 5 ns laser pulses at 532 nm. Numerical fitting of the measured Z-scan data to the relevant nonlinear transmission equations reveals that the nonlinear absorption is arising from strong excited state absorption, along with weak absorption saturation and it is found that the optical nonlinearity of Tb2(MoO4)3 increases with Sm3+/Eu3+doping. Parameters such as saturation fluence, excited state absorption cross section and ground state absorption cross section of the samples have been determined numerically, from which the figure of merit for nonlinear absorption is calculated. The excited state absorption cross-section of the samples is found to be one order of magnitude higher than that of the ground state absorption cross-section, indicating strong reverse saturable absorption. These results indicate that Sm3+/Eu3+ doped Tb2(MoO4)3 nanophosphors are efficient media for UV/n-UV pumped LEDs, and are also potential candidates for designing efficient optical limiting devices for the protection of human eyes and sensitive optical detectors from harmful laser radiation.

  10. Colloidal GdVO4:Eu3+@SiO2 nanocrystals for highly selective and sensitive detection of Cu2+ ions

    Science.gov (United States)

    Liang, Yanjie; Noh, Hyeon Mi; Park, Sung Heum; Choi, Byung Chun; Jeong, Jung Hyun

    2018-03-01

    Nowadays, in view of health and safety demands, the controlled design of selective and sensitive sensors for Cu2+ detection is of considerable importance. Therefore, we construct herein core-shell colloidal GdVO4:Eu3+@SiO2 nanocrystals (NCs) as optical sensor for the detection of Cu2+, which were synthesized by a facile hydrothermal reaction and encapsulated with a uniform layer of ultrathin silica through a sol-gel strategy. The NCs present strong red emission due to energy transfer from VO43- groups to Eu3+ when exciting with ultraviolet (UV) light. This intense red emission from Eu3+ could be selectively quenched in the presence of Cu2+ in comparison to other metal ions and the limit of detection is as low as 80 nM in aqueous solution. It is revealed that the spectral overlap between the emission band of NCs and the absorption of Cu2+ accounts for this intriguing luminescence behavior. The detection ability is highly reversible by the addition of ethylenediaminetetraacetic acid (EDTA) with the recovery of almost 100% of the original luminescence. The luminescence quenching and recovery processes can be performed repeatedly with good sensing ability. These remarkable performances allow the colloidal GdVO4:Eu3+@SiO2 NCs a promising fluorescence chemosensor for detecting Cu2+ ions in aqueous solution.

  11. Luminescent properties of complexly substituted oxides Ме2Ln8 (XO46O2 (Me=Sr, Ca; Ln=La, Gd, Eu; X= Si, P

    Directory of Open Access Journals (Sweden)

    A. A. Vasin

    2014-11-01

    Full Text Available In the current work it is established that the maximum intensity of a luminescence of crystalline phosphors with structure silicate-apatite of general formulae: Ca2Eu8Si6(1-xP6xO26, Sr2Gd7.2Eu0.8Si6(1-xP6xO26 and Ca2La8(1-xEu8xSi6O26 is reached at concentration of europium equal 0,15. The maximum intensity of a luminescence of these substances, at replacement in an anion sublattice of tetrahedrons [SiO4]4- on tetrahedrons [PO4]3- takes place at concentration of phosphorus 0,05.

  12. Y3Al5O12:Re3+ (Re=Ce, Eu, and Sm nanocrystalline powders prepared by modified glycine combustion method

    Directory of Open Access Journals (Sweden)

    Lojpur V.

    2014-01-01

    Full Text Available Yttrium aluminum garnet doped with rare earth ions (Ce3+, Eu3+ and Sm3+ was prepared by modified glycine method. Ce3+ as a dopant was used in four different concentrations (Y3-xCexAl5O12; x(% = 1, 2, 3, 5, while doping concentration of Eu3+ and Sm3+ was Y3-xEuxAl5O12; x(% = 3 and Y3-xSmxAl5O12; x(% = 1, respectively. Phase composition of powders was investigated using XRD technique and expected target phase was confirmed. Photoluminescent characterization included measurements of excitation and emission spectra, as well as determination of emission decays. Y3-xCexAl5O12 shows intense broad-band emission, with maximum in green spectral region, at about 524 nm under ultraviolet or blue excitation. The origin of the luminescence is the 5d1→4f1 transition which is both parity and spin allowed. Ultraviolet and blue excitations of Eu3+ and Sm3+ doped Y3Al5O12 produce intense orange and red emissions. These emissions are phosphorescent in character and come from spin forbidden f-f electron transitions in Eu3+ and Sm3+ ions. For the case of Eu3+ doping emission comes mainly from 5D0→7F1 transitions with Stark components peaking at 590 nm and 590.75 nm, and with emission decay of 4.15 ms. In the case of Sm3+ doping, the emission spectrum, shows 4G5/2→6H5/2, 4G5/2→6H7/2, and 4G5/2→6H9/2 transitions, with the most intense stark components positioned at 567.5 nm, 617 nm, and 650 nm, respectively and for transition centered at 617 nm, emission decay is 3.12 ms. [Projekat Ministarstva nauke Republike Srbije, br. 171022 i br. 45012

  13. Angular non-critical phase-matching second-harmonic-generation characteristics of RECOB (RE = Tm, Y, Gd, Sm, Nd and La) crystals.

    Science.gov (United States)

    Liu, Yanqing; Wang, Zhengping; Yu, Fapeng; Qi, Hongwei; Yang, Xiuqin; Yu, Xiaoqiang; Zhao, Xian; Xu, Xinguang

    2017-05-15

    For the first time, the angular non-critical phase-matching (A-NCPM) second-harmonic-generation (SHG) characteristics of a family of monoclinic oxoborate crystals, RECa 4 O(BO 3 ) 3 (RECOB, RE = Tm, Y, Gd, Sm, Nd and La), were comprehensively investigated. For all of the realizable A-NCPM SHG styles, the feature parameters including PM wavelength, angular, wavelength and temperature acceptance bandwidths, have been derived from the theory and verified by the experiments. We discovered that the closer the ion radius between RE 3+ and Ca 2+ , the smaller the birefringence, and the better the A-NCPM SHG properties. As a result, for the Type-I SHG on Y-axis which has the largest effective nonlinear optical coefficient (d eff ) among the three realizable A-NCPM styles, NdCOB crystal presents the longest PM wavelength (927 nm), the largest angular acceptance bandwidth (Δθ⋅l 1/2 = 84.3 mrad·cm 1/2 , Δϕ⋅l 1/2 = 58.8 mrad·cm 1/2 ), and the broadest wavelength acceptance bandwidth (8.7 nm). This discovery will contribute to the design of new NCPM materials, at the same time the parameter formula will be helpful for the theoretical prediction of NCPM performance.

  14. Phase relationships and cation disorder in RE{sub 1+x}Ba{sub 2-x}Cu{sub 3}O{sub 7+{delta}}, RE = Pr, Nd, Sm, Gd

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, M.J.; Wu, H.; Dennis, K.W.; Polzin, B.I.; Falzgraf, D.K.; McCallum, R.W.

    1995-12-31

    Unlike Y123 which forms only a stoichiometric compound, the light arare earth elements (LRE) form a solid solution LRE{sub 1+x}Ba{sub 2-x}Cu{sub 3}O{sub 7+{delta}} (LRE123ss), with increasing substitution of the LRE{sup 3+} for the Ba{sup 2+} as the ionic radii of the LRE increases. The sub-solidus phase relationships around the LRE123ss change for La, Pr and Nd, but are similar for Sm and Gd. However, the solubility limit decreases with decreasing ionic radii. In addition, the solubility limits for Sm and Gd are strongly influenced by PO{sub 2} during high temperature annealing. The range of solubility is, for any given LRE system, strongly dependent on the oxygen partial pressure (PO{sub 2}) providing a new means by which to control the microstructure in the RE123 system.

  15. Charge disproportionation in (X0.6Sr0.4)0.99Fe0.8Co0.2O3-δ perovskites (X = La, Pr, Sm, Gd)

    DEFF Research Database (Denmark)

    Pedersen, Thomas; Saadi, Souheil; Nielsen, K.H.

    2005-01-01

    The change in crystal structure and the oxidation state in iron of iron-cobalt-based perovskites with different A-site cations is investigated by the use of powder XRD and Mossbauer spectroscopy. The perovskites investigated are (X0.6Sr0.4)(0.99)Fe0.8Co0.2O3-delta, where X is La, Pr, Sm or Gd...

  16. An analysis on structural and magnetic properties of La{sub 1-x}RE{sub x}FeO{sub 3} (x = 0.0 and 0.5, RE = Nd, Sm and Gd) nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Blessington Selvadurai, A. Paul; Pazhanivelu, V.; Jagadeeshwaran, C.; Murugaraj, R. [Anna University, Department of Physics, Chennai (India); Gazzali, P.M. Mohammed; Chandrasekaran, G. [Pondicherry University, Department of Physics, Pudhucherry (India)

    2017-01-15

    La{sub 1-x}RE{sub x}FeO{sub 3} (x = 0.0 and 0.5, RE = Nd, Sm and Gd) is synthesised by sol-gel citrate combustion method. X-ray diffraction (XRD) and Raman spectra show orthorhombic phase with Pbnm symmetry, confirmed by profile fitting and Raman modes analysis for La{sub 1-x}R{sub x}FeO{sub 3} samples. The estimated crystallite size and the orthorhombic strain of La{sub 1-x}RE{sub x}FeO{sub 3} (x = 0.0 and 0.5, RE = Nd, Sm and Gd) from XRD data illustrate the role of ionic size substitution. The temperature- and field-dependent magnetisation M(T) and M(H) were measured using vibrating sample magnetometer. The M(H) curve parameters of La{sub 1-x}RE{sub x}FeO{sub 3}(x = 0.5, RE = Nd and Gd) exhibit a relation of M{sub r} ∝ (1)/(H{sub c}) and H{sub ex} ∝ H{sub C} at 20, 150 and 300 K. The M (T) curve of La{sub 0.5}Nd{sub 0.5}FeO{sub 3} and La{sub 0.5}Gd{sub 0.5}FeO{sub 3} indicates the paramagnetic-like behaviour, whereas the M (H) curve reveals the antiferromagnetic signature in them. The M (H) curve of La{sub 0.5}Sm{sub 0.5}FeO{sub 3} shows a strong AFM pinned ferromagnetism and ferromagnetism (FM) at 150 and 20 K, respectively. Further, field-cooled (FC) and zero-field-cooled (ZFC) measurement of La{sub 0.5}Sm{sub 0.5}FeO{sub 3} indicates a competitive interaction of AFM-FM, which is emphasised by a broad blocking temperature at ∝117 K in ZFC curve. The FM-like ordering of Sm{sup 3+} ions are observed below at ∝150 K in FC curve of La{sub 0.5}Sm{sub 0.5}FeO{sub 3}. In addition, the electron paramagnetic resonance spectra at room temperature show a high g value and a strong non-homogenous broadening for La{sub 0.5}Sm{sub 0.5}FeO{sub 3}. (orig.)

  17. Effect of temperature on optical spectra and relaxation dynamics of Sm{sup 3+} in Gd{sub 3}Ga{sub 5}O{sub 12} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Lisiecki, Radosław, E-mail: R.Lisiecki@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-422 Wrocław (Poland); Ryba-Romanowski, Witold; Solarz, Piotr; Strzęp, Adam [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-422 Wrocław (Poland); Berkowski, Marek [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

    2014-01-05

    Highlights: • Influence of temperature on optical properties of the Gd{sub 3}Ga{sub 5}O{sub 12}:Sm single crystals. • Analysis of absorption and emission spectra as well as luminescence lifetimes. • Estimation of energies of crystal field components of Sm{sup 3+} in the Gd{sub 3}Ga{sub 5}O{sub 12} crystal. • Study on energy transfer phenomena using the classical Inokuti–Hirayama model. -- Abstract: Single crystals of Gd{sub 3}Ga{sub 5}O{sub 12} (GGG) doped with 2 at.% and 10 at.% of Sm{sup 3+} were fabricated by the Czochralski method. Optical absorption and emission spectra as well as luminescence decay curves for these crystals were recorded at different temperatures ranging from 5 K to 300 K. The energies of the crystal field sublevels of selected multiplets were determined based on optical spectra recorded at T = 5 K. It has been found that widths of spectral lines related to transitions between individual crystal field levels of multiplets involved increase by factors of 5–7 when the sample temperature grows from 5 K to 300 K. In contrast to this the positions of spectral lines appear to be independent of temperature. Temperature dependence of the {sup 4}G{sub 5/2} luminescence lifetime was determined for both concentrations of samarium. Luminescence decay curves follow a single-exponential time dependence when Sm{sup 3+} concentration amounts to 2 at.% but a non-exponential decay kinetic and efficient quenching process were observed in highly-doped sample. The Inokuti–Hirayama classical energy transfer model was utilized successfully to account for time dependence of an experimental decay curves recorded for GGG:10 at.% Sm crystal.

  18. Zero-field splitting in the isoelectronic aqueous Gd(III) and Eu(II) complexes from a first principles analysis

    Science.gov (United States)

    Khan, S.; Peters, V.; Kowalewski, J.; Odelius, M.

    2018-03-01

    The zero-field splitting (ZFS) of the ground state octet in aqueous Eu(II) and Gd(III) solutions was investigated through multi- configurational quantum chemical calculations and ab initio molecular dynamics (AIMD) simulations. Investigation of the ZFS of the lanthanide ions is essential to understand the electron spin dynamics and nuclear spin relaxation around paramagnetic ions and consequently the mechanisms underlying applications like magnetic resonance imaging. We found by comparing clusters at identical geometries but different metallic centres that there is not a simple relationship for their ZFS, in spite of the complexes being isoelectronic - each containing 7 unpaired f electrons. Through sampling it was established that inclusion of the first hydration shell has a dominant (over 90 %) influence on the ZFS. Extended sampling of aqueous Gd(III) showed that the 2 nd order spin Hamiltonian formalism is valid and that the rhombic ZFS component is decisive.

  19. Synthesis of three-dimensional flower-like BiOCl:RE{sup 3+} (RE{sup 3+} = Eu{sup 3+}, Sm{sup 3+}) globular microarchitectures and their luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yang-Yang; Zhang, Zhi-Jun [Department of Physics, Dongguk University, Seoul, 100715 (Korea, Republic of); Zhu, Gang-Qiang [Department of Physics, Shanxi Normal University, Xi’an, 710062 (China); Yang, Woochul, E-mail: wyang@dongguk.edu [Department of Physics, Dongguk University, Seoul, 100715 (Korea, Republic of)

    2016-12-01

    Graphical abstract: - Highlights: • Three-dimensional flower-like Eu{sup 3+} and Sm{sup 3+}-activated BiOCl globular microarchitectures have been synthesized. • Ostwald ripening and recrystallization are responsible for the growth mechanism of BiOCl microarchitectures. • Efficient red-emission from Eu{sup 3+}:BiOCl is observed due to the well-crystallized structures of the microarchitectures. - Abstract: Three-dimensional flower-like Eu{sup 3+} and Sm{sup 3+}-activated BiOCl globular microarchitectures were synthesized by the solvothermal method employing urea as a dispersing agent for the first time. The crystal structure, morphologies and luminescence properties of Eu{sup 3+} and Sm{sup 3+} doped BiOCl have been systematically investigated by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) and spectroscopy, respectively. The unit cell volumes show a nearly linear decrease by about 0.18 and 0.15% with increasing Eu{sup 3+} and Sm{sup 3+} concentration up to 9 mol%, respectively. All of the prepared samples show flower-like globular microarchitectures with an average diameter about 3–5 μm with different Eu{sup 3+} and Sm{sup 3+} concentrations. Possible formation mechanism for the flower-like microarchitectures is proposed on the basis of time-dependent experiment. Both BiOCl:Eu{sup 3+} and BiOCl:Sm{sup 3+} samples show a strong red emission corresponding to the {sup 5}D{sub 0} → {sup 7}F{sub 4} transition (700 nm) of Eu{sup 3+} and {sup 4}G{sub 5/2} → {sup 6}H{sub 7/2} transition (600 nm) of Sm{sup 3+}, respectively. This work sheds some light on the design and preparation of red-emitting phosphors with novel microstructures.

  20. Optical characterization and the energy level scheme for NaYP{sub 2}O{sub 7}:Ln{sup 3+} (Ln=Ce, Sm, Eu, Tb, Yb)

    Energy Technology Data Exchange (ETDEWEB)

    Novais, S.M.V., E-mail: suellenvaleriano@yahoo.com.br [Laboratory of Advanced Ceramic Materials, Physics Department, Federal University of Sergipe, 49.100-000, São Cristóvão, SE (Brazil); Dobrowolska, A.; Bos, A.J.J.; Dorenbos, P. [Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Macedo, Z.S. [Laboratory of Advanced Ceramic Materials, Physics Department, Federal University of Sergipe, 49.100-000, São Cristóvão, SE (Brazil)

    2014-04-15

    Vacuum ultra-violet spectroscopy at low temperature was performed with undoped and Ln{sup 3+}-doped NaYP{sub 2}O{sub 7} (Ln=Ce, Sm, Eu, Tb and Yb). The emission observed from the NaYP{sub 2}O{sub 7} host was attributed to self-trapped exciton (STE) recombination. Dopant ions were well incorporated and responsible for characteristic luminescent emission in the doped samples. From excitation curves, 4f–5d transitions were identified for Ce{sup 3+}, Sm{sup 3+} and Tb{sup 3+} and charge transfer processes were noticed for Eu{sup 3+}, Sm{sup 3+} and Yb{sup 3+}. The experimental data obtained was used to determine the positions of the energy levels of divalent and trivalent lanthanides relative to the valence and conduction band of this compound. The experimentally derived levels are in good agreement with model predictions. The results are valuable to provide a better understanding on the performance of NaYP{sub 2}O{sub 7} and related diphosphates as luminescent materials. -- Highlights: • NaYP{sub 2}O{sub 7} polycrystalline samples were produced via the sol–gel method. • VUV excitation and emission spectra were successfully studied. • Luminescent properties were discussed. • The experimentally derived energy levels are in good agreement with model predictions.

  1. Optical and crystal chemistry studies of Na3Ln(PO4)2-K3Ln(PO4)2 (Ln=Eu, Gd)

    International Nuclear Information System (INIS)

    Mesnaoui, M.; Maazaz, M.

    1987-01-01

    In these systems, large single phase domains are separated by two phase regions. The structural evolution as a function of composition is analysed both by X-ray diffraction and by using Eu 3+ and Gd 3+ as luminescent local structural probes. Due to layer type structure of the K 3 Ln(PO 4 ) 2 phases an exchange reaction resulting in total substitution of sodium for potassium can be carried out with formation of metastable Na 3 Ln(PO 4 ) 2 phases, the structure of which is close to those of the potassium compounds. 10 refs.; 18 figs [fr

  2. Synthesis and luminescence characterization of Y2BaZnO5:RE (RE = Eu3+, Tb3+, Pr3+and Sm3+) phosphors.

    Science.gov (United States)

    Taikar, D R; Joshi, C P; Moharil, S V

    2017-09-01

    Modified synthesis and luminescence of Y 2 BaZnO 5 phosphors activated with the rare earths (RE) Eu 3 + , Tb 3 + , Pr 3 + and Sm 3 + are reported. RE 2 BaZnO 5 phosphors have attracted attention because of their interesting magnetic and optical properties; and are usually prepared using a two-step solid-state reaction. In the first step, carbonates or similar precursors are thoroughly mixed and heated at 900°C to decompose them to oxides. To eliminate the unwanted phases like BaRE 2 O 4 , the resulting powders are reheated at 1100°C for a long time. We prepared Y 2 BaZnO 5 phosphors activated with various activators by replacing the first step with combustion synthesis. The photoluminescence results are presented. The photoluminescence results for Eu 3 + , Tb 3 + and Pr 3 + are in good agreement with the literature. However, photoluminescence emission from Sm 3 + has not been documented previously. The excitation spectrum of Eu 3 + is dominated by a charge transfer band around 261 nm, and an additional band around 238 nm is always present, irrespective of the type of activator. The presence of this band for all these different types of activators was interpreted as host absorption. Copyright © 2016 John Wiley & Sons, Ltd.

  3. A simple approach for the synthesis of bifunctional Fe{sub 3}O{sub 4}-Gd{sub 2}O{sub 3}:Eu{sup 3+} core-shell nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Peng Hongxia [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shanxi Key Laboratory of Physico-Inorganic Chemistry, School of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Cui Bin, E-mail: cuibin@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shanxi Key Laboratory of Physico-Inorganic Chemistry, School of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Li Leilei; Wang Yingsai [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shanxi Key Laboratory of Physico-Inorganic Chemistry, School of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China)

    2012-08-05

    Graphical abstract: The TEM images reveal that Fe{sub 3}O{sub 4}-Gd{sub 2}O{sub 3}:Eu{sup 3+} nanoparticles have a particle size ranging from 175 nm to 300 nm and keep the spherical morphology, core-shell structures, non-aggregation and rough surface. The results revealed that the Gd{sub 2}O{sub 3}:Eu{sup 3+} phosphor layer uniformly deposited on Fe{sub 3}O{sub 4} nanoparticles and thicknesses of Gd{sub 2}O{sub 3}:Eu{sup 3+} are 20-30 nm. The selected-area electron diffraction (SAED) reveals the polycrystalline feature of the as-prepared product. Highlights: Black-Right-Pointing-Pointer Bifunctional magnetic-luminescent Fe{sub 3}O{sub 4}-Gd{sub 2}O{sub 3}:Eu{sup 3+} nanoparticles with core-shell structures have been successfully fabricated by a facile, green, and efficient hydrothermal method. Black-Right-Pointing-Pointer Fe{sub 3}O{sub 4}-Gd{sub 2}O{sub 3}:Eu{sup 3+} composites have robust magnetic responsive properties and strong luminescent properties. Black-Right-Pointing-Pointer Fe{sub 3}O{sub 4}-Gd{sub 2}O{sub 3}:Eu{sup 3+} nanoparticles have great potential applications in drug targeting, bioseparation and diagnostic analysis. - Abstract: Bifunctional magnetic-luminescent Fe{sub 3}O{sub 4}-Gd{sub 2}O{sub 3}:Eu{sup 3+} nanoparticles with core-shell structures have been successfully fabricated using a simple, green, and efficient hydrothermal method. These materials were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) spectra, and a superconducting quantum interference device (SQUID) magnetometer. The results showed that the spinel of the Fe{sub 3}O{sub 4} cores was uniformly coated with Gd{sub 2}O{sub 3}:Eu{sup 3+} layers. The inner Fe{sub 3}O{sub 4} cores and the outer Gd{sub 2}O{sub 3}:Eu{sup 3+} layers yielded composites that combine magnetic-responsive and luminescent properties, thus, nanoparticles of the composite may find potential applications in drug targeting, bioseparation, and

  4. Elaboration of nanostructured Eu{sup 3+}-doped Gd{sub 2}O{sub 3} phosphor fine spherical powders using polyol-mediated synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Gonzalez, M.A.; Louis, C.; Bazzi, R.; Ledoux, G.; Lebbou, K.; Roux, S.; Tillement, O. [Universite Claude Bernard Lyon 1, LPCML, Villeurbanne (France); Perriat, P. [INSA de Lyon, GEMPPM, UMR, Villeurbanne (France)

    2005-11-01

    Red-emitting Eu{sup 3+}-doped Gd{sub 2}O{sub 3} spherical powders were directly precipitated using a polyol method. The as-synthesized powders consist of agglomerates with a spherical shape and a size ranging between 0.4 and 0.6 {mu}m. Each agglomerate is nanostructured and consists of a packing of nanocrystallites (3-5 nm) of a bcc oxide phase whose luminescence presents original features in comparison with bulk materials. The powders were further calcinated and the size of both crystallites and agglomerates, the crystalline structure and the luminescence were studied as a function of the annealing temperature. For temperatures lower than 900 C, the samples obtained are highly crystalline and possess the classical Eu{sup 3+} red luminescence. For optimized temperature, the morphology of the particles can be preserved leading to spherical, dense, luminescent and almost monodisperse oxide powders, 0.5 {mu}m in size. (orig.)

  5. Bifunctional ferromagnetic Eu-Gd-Bi-codoped hybrid organo-silica red emitting phosphors synthesized by a modified Pechini sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Abo-Naf, S.M., E-mail: sm.abo-naf@nrc.sci.eg [Glass Research Department, National Research Centre (NRC), El-Buhouth Str., Dokki, 12622 Cairo (Egypt); Abdel-Hameed, S.A.M.; Marzouk, M.A. [Glass Research Department, National Research Centre (NRC), El-Buhouth Str., Dokki, 12622 Cairo (Egypt); Hamdy, Y.M. [Spectroscopy Department, National Research Centre (NRC), El-Buhouth Str., Dokki, 12622 Cairo (Egypt)

    2017-06-15

    Red phosphor, composed of Eu-Gd-Bi-codoped hybrid organo-silica glass, has been synthesized via a modified Pechini sol-gel process. The synthesized hybrid glass was analyzed with powder X-ray diffraction (XRD), differential thermal analysis coupled with thermogravimetry (DTA-TG) and Fourier transform infrared (FTIR) spectroscopy. XRD and DTA-TG confirmed its amorphous structure up to 1000 °C. Magnetic behavior of the produced phosphor was investigated using vibrating specimen magnetometer (VSM) and the obtained results revealed its unsaturated ferromagnetic behavior. Photoluminescence (PL) properties of the obtained phosphor have been investigated under near-UV excitation at 395 nm. The influence of calcination temperature on the PL intensity and its decay behavior as well as on the ferromagnetic characteristics has been studied to determine the optimal reaction temperature of the phosphor. The PL emission spectra show the characteristic emission bands of Eu{sup 3+} ions in the wavelength range from 580 to 700 nm. These emission spectra have been dominated by the electric dipole {sup 5}D{sub 0}→{sup 7}F{sub 2} transition of the Eu{sup 3+} peaked at 610–620 nm producing the red light emission of the phosphors. It was found that the phosphor performance, expressed by its PL intensity and life time, could be significantly improved by increasing of the heat treatment temperature up to 900 °C. Also, calcination at 900 °C for 6 h greatly increased both of the magnetization and retentivity, while decreased the coercivity value. The organic phenomenon of metal citrate-ethylene glycol chelation and its degradation by calcination were well followed by FTIR spectroscopy. The obtained results are promising and could afford a basis for designing of efficient red phosphors for displays, lighting and bifunctional biosensors for biomedical applications. - Highlights: • Eu-Gd-Bi-codoped hybrid organo-silica phosphor was synthesized by sol-gel method. • Inorganic Eu-Gd

  6. In vivo immunotoxicity of SiO2@(Y0.5Gd0.45Eu0.05)2O3 as dual-modality nanoprobes.

    Science.gov (United States)

    Tian, Xiumei; Li, Ermao; Yang, Fanwen; Peng, Ye; Zhu, Jixiang; He, Fupo; Chen, Xiaoming

    2014-08-07

    We have successfully synthesized SiO2@(Y0.5Gd0.45Eu0.05)2O3 nanocomposites as a potential dual-modality nanoprobe for molecular imaging in vitro. However, their immunotoxicity assessment in vivo remains unknown. In this article, the in vitro biocompatibility of our dual-modality nanoprobes was assayed in terms of cell viability and apoptosis. In vivo immunotoxicity was investigated by monitoring the generation of reactive oxygen species (ROS), cluster of differentiation (CD) markers and cytokines in Balb/c mice. The data show that the in vitro biocompatibility was satisfactory. In addition, the immunotoxicity data revealed there are no significant changes in the expression levels of CD11b and CD71 between the nanoprobe group and the Gd in a diethylenetriaminepentaacetic acid (DTPA) chelator (Gd-DTPA) group 24 h after injection in Balb/c mice (p>0.05). Importantly, there are significant differences in the expression levels of CD206 and CD25 as well as the secretion of IL-4 and the generation of ROS 24 h after injection (pimmunotoxicity of these rare earth-based biomaterials at the molecular level before molecular imaging in vivo.

  7. Synthesis and characterization of (3-Aminopropyl)trimethoxy-silane (APTMS) functionalized Gd2O3:Eu3+ red phosphor with enhanced quantum yield

    International Nuclear Information System (INIS)

    Jain, Akhil; Hirata, G A; Farías, M H; Castillón, F F

    2016-01-01

    We report the surface modification of nanocrystalline Gd 2 O 3 :Eu 3+ phosphor by (3-Aminopropyl)trimethoxysilane (APTMS). The nanoparticles were first coated with silica using the Stöber process, and then annealed at 650 °C for 2 h. Afterwards, APTMS was functionalized onto the silica layer to obtain Gd 2 O 3 :Eu 3+ nanoparticles bearing amine groups on the surface. The effect of silica coating, and the subsequent annealing process on the crystallization of the nanophosphor were analyzed by x-ray diffraction (XRD). High-resolution transmission electron microscopy (HR-TEM) confirmed the presence of a silica layer of ∼45 nm thickness. X-ray photoelectron (XPS) and Fourier transform infrared (FTIR) spectroscopy confirmed the presence of silica and the amine groups. Photoluminescence (PL) analysis demonstrated an increased emission after functionalization of nanoparticles. Absolute quantum yield (QY) measurements revealed an 18% enhancement in QY in functionalized nanoparticles compared with unmodified nanoparticles, which is of great importance for their biomedical applications. (paper)

  8. Ternary rhombohedral Laves phases RE{sub 2}Rh{sub 3}Ga (RE = Y, La-Nd, Sm, Gd-Er)

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Stefan; Benndorf, Christopher; Heletta, Lukas; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Janka, Oliver [Oldenburg Univ. (Germany). Inst. fuer Chemie; Mausolf, Bernhard [RWTH Aachen (Germany). Inst. fuer Anorganische Chemie; Haarmann, Frank [RWTH Aachen (Germany). Inst. fuer Anorganische Chemie; Max-Planck-Institut fuer Chemische Physik fester Stoffe, Dresden (Germany); Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Sao Paulo Univ., Sao Carlos (Brazil). Inst. of Physics

    2017-06-01

    The ordered Laves phases RE{sub 2}Rh{sub 3}Ga (RE=Y, La-Nd, Sm, Gd-Er) were synthesized by arc-melting of the elements and subsequent annealing. The samples were characterized by powder X-ray diffraction (XRD). They crystallize with the rhombohedral Mg{sub 2}Ni{sub 3}Si type structure, space group R3m. Three structures were refined from single crystal X-ray diffractometer data: a=557.1(1), c=1183.1(2), wR2=0.0591, 159 F{sup 2} values, 10 variables for Y{sub 2}Rh{sub 3}Ga, a=562.5(2), c=1194.4(2) pm, wR2=0.0519, 206 F{sup 2} values, 11 variables for Ce{sub 2}Rh{sub 3}Ga and a=556.7(2), c=1184.1(3) pm, wR2=0.0396, 176 F{sup 2} values, 11 variables for Tb{sub 2}Rh{sub 3}Ga. The Rh{sub 3}Ga tetrahedra are condensed via common corners and the large cavities left by the network are filled by the rare earth atoms. The RE{sub 2}Rh{sub 3}Ga Laves phases crystallize with a translationengleiche subgroup of the cubic RERh{sub 2} Laves phases with MgCu{sub 2} type. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y{sub 2}Rh{sub 3}Ga and La{sub 2}Rh{sub 3}Ga. Ce{sub 2}Rh{sub 3}Ga shows intermediate cerium valence while all other RE{sub 2}Rh{sub 3}Ga phases are Curie-Weiss paramagnets which order magnetically at low temperatures. The {sup 89}Y and {sup 71}Ga solid state nuclear magnetic resonance (NMR) spectra of the diamagnetic representative Y{sub 2}Rh{sub 3}Ga show well-defined single resonances in agreement with an ordered bulk phase. In comparison to the binary Laves phase YRh{sub 2} a strongly increased {sup 89}Y resonance frequency is observed owing to a higher s-electron spin density at the {sup 89}Y nuclei as proven by density of states (DOS) calculations.

  9. Complexes of o-Vanillin oxime with La(III), Ce(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III), Ho(III) and Yb(III)

    International Nuclear Information System (INIS)

    Dhar, M.L.; Gupta, V.K.; Singh, Onkar

    1988-01-01

    Ten complexes of lanthanides with o-vanillin oxime have been swynthesised and characterised. The composition of the complexes as determined by elemental and thermal analyses, infrared electronic spectral and magnetic moment studies is [Ln(C 8 H 8 NO 3 ) 3 .XH 2 O], where X=2 when Ln=La, Ce, Pr, Nd, Sm and X=3 when Ln=Gd, Dy, Tb, Ho, Yb; C 8 H 8 NO 3 - represents the anion of the ligand. (author). 16 refs., 2 figs., 2 tables

  10. Syntheses, structures, and properties of a series of novel high-nuclear 3d-4f clusters with mixed amino acids as ligands: {Ln6Cu24}(Ln = Gd, Tb, Pr and Sm).

    Science.gov (United States)

    Shen, Chao-Jun; Hu, Sheng-Min; Sheng, Tian-Lu; Xue, Zhen-Zhen; Wu, Xin-Tao

    2015-04-14

    The first examples of high-nuclear 3d-4f heterometallic clusters with mixed amino acid ligands are reported. Four 30-nuclear clusters {Ln6Cu24}(Ln = Gd, Tb, Pr and Sm) were obtained through the self-assembly of Ln(III), Cu(II) and mixed amino acid ligands of glycine (HGly) and β-alanine (HAla). The metal skeleton of clusters may be described as a huge {Ln6Cu12} octahedron connected with 12 additional Cu(II) ions. The temperature dependence of magnetic susceptibilities of compounds were also studied.

  11. EU

    DEFF Research Database (Denmark)

    Abrahamson, Peter; Borchorst, Anette

    2002-01-01

    Der er et komplekst forhold mellem EU og den danske velfærdsstat. Den sociale dimension i det europæiske samarbejde er splittet mellem et pres mod harmonisering og pres for at fastholde national suverænitet. Negativ integration har været den foretrukne interventionsform. Drivkræfterne har især...

  12. Preparation and characterization of electroluminescent devices based on complexes of β-diketonates of Tb3+, Eu3+, Gd3+ ions with macrocyclic ligands and UO22+ films

    International Nuclear Information System (INIS)

    Gibelli, Edison Bessa

    2010-01-01

    Complexes containing Rare Earth ions are of great interest in the manufacture of electro luminescent devices as organic light emitting devices (OLED). These devices, using rare earth trivalent ions (TR 3+ ) as emitting centers, show high luminescence with extremely fine spectral bands due to the structure of their energy levels, long life time and high quantum efficiency. This work reports the preparation of Rare Earth β-diketonate complexes (Tb 3+ , Eu 3+ and Gd 3+ ) and (tta - thenoyltrifluoroacetonate and acac - acetylacetonate) containing a ligand macrocyclic crown ether (DB18C6 - dibenzo18coroa6) and polymer films of UO 2 2+ . The materials were characterized by complexometric titration with EDTA, CH elemental analysis, near infrared absorption spectroscopy, thermal analysis, X-ray diffraction (powder method) and luminescence spectroscopy. For manufacturing the OLED it was used the technique of deposition of thin films by physical vapor (PVD, Physical Vapor Deposition). (author)

  13. In Vivo Immunotoxicity of SiO2@(Y0.5Gd0.45Eu0.052O3 as Dual-Modality Nanoprobes

    Directory of Open Access Journals (Sweden)

    Xiumei Tian

    2014-08-01

    Full Text Available We have successfully synthesized SiO2@(Y0.5Gd0.45Eu0.052O3 nanocomposites as a potential dual-modality nanoprobe for molecular imaging in vitro. However, their immunotoxicity assessment in vivo remains unknown. In this article, the in vitro biocompatibility of our dual-modality nanoprobes was assayed in terms of cell viability and apoptosis. In vivo immunotoxicity was investigated by monitoring the generation of reactive oxygen species (ROS, cluster of differentiation (CD markers and cytokines in Balb/c mice. The data show that the in vitro biocompatibility was satisfactory. In addition, the immunotoxicity data revealed there are no significant changes in the expression levels of CD11b and CD71 between the nanoprobe group and the Gd in a diethylenetriaminepentaacetic acid (DTPA chelator (Gd-DTPA group 24 h after injection in Balb/c mice (p > 0.05. Importantly, there are significant differences in the expression levels of CD206 and CD25 as well as the secretion of IL-4 and the generation of ROS 24 h after injection (p < 0.05. Transmission electron microscopy (TEM images showed that few nanoprobes were localized in the phagosomes of liver and lung. In conclusion, the toxic effects of our nanoprobes may mainly result from the aggregation of particles in phagosomes. This accumulation may damage the microstructure of the cells and generate oxidative stress reactions that further stimulate the immune response. Therefore, it is important to evaluate the in vivo immunotoxicity of these rare earth-based biomaterials at the molecular level before molecular imaging in vivo.

  14. Photoemission Study of the Rare Earth Intermetallic Compounds: RNi2Ge2 (R=Eu, Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jongik [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    EuNi2Ge2 and GdNi2Ge2 are two members of the RT2X2 (R = rare earth, T = transition metal and X = Si, Ge) family of intermetallic compounds, which has been studied since the early 1980s. These ternary rare-earth intermetallic compounds with the tetragonal ThCr2Si2 structure are known for their wide variety of magnetic properties, Extensive studies of the RT2X2 series can be found in Refs [ 1,2,3]. The magnetic properties of the rare-earth nickel germanides RNi2Ge2 were recently studied in more detail [4]. The purpose of this dissertation is to investigate the electronic structure (both valence band and shallow core levels) of single crystals of EuNi2Ge2 and GdNi2Ge2 and to check the assumptions that the f electrons are non-interacting and, consequently, the rigid-band model for these crystals would work [11], using synchrotron radiation because, to the best of our knowledge, no photoemission measurements on those have been reported. Photoemission spectroscopy has been widely used to study the detailed electronic structure of metals and alloys, and especially angle-resolved photoemission spectroscopy (ARPES) has proven to be a powerful technique for investigating Fermi surfaces (FSs) of single-crystal compounds.

  15. Lattice dynamical investigation of the Raman and infrared wave numbers and heat capacity properties of the pyrochlores R2Zr2O7 (R = La, Nd, Sm, Eu)

    Science.gov (United States)

    Nandi, S.; Jana, Y. M.; Gupta, H. C.

    2018-04-01

    A short-range electrostatic forcefield model has been applied for the first time to investigate the Raman and infrared wave numbers in pyrochlore zirconates R2Zr2O7 (R3+ = La, Nd, Sm, Eu). The calculations of phonons involve five stretching and four bending force constants in the Wilson GF matrix method. The calculated phonon wave numbers are in reasonable agreement with the observed spectra in infrared and Raman excitation zones for all of these isomorphous compounds. The contributions of force constants to each mode show a similar trend of variation for all of these compounds. Furthermore, to validate the established forcefield model, we calculated the standard thermodynamic functions, e.g., molar heat capacity, entropy and enthalpy, and compared the results with the previous experimental data for each compound. Using the derived wave numbers for the acoustic and optical modes, the total phonon contribution to the heat capacity was calculated for all these zirconate compounds. The Schottky heat capacity contributions were also calculated for the magnetic compounds, Nd2Zr2O7, Sm2Zr2O7 and Eu2Zr2O7, taking account of crystal-field level schemes of the lanthanide ions. The derived total heat capacity and the integrated values of molar entropy and molar enthalpy showed satisfactory correlations at low temperatures with the experimental results available in the literature for these compounds. At higher temperatures, the discrepancies may be caused by the anharmonic effects of vibrations, phonon dispersion, distribution of phonon density of states, etc.

  16. Crystallographic and magnetic properties of R sub 3 Fe sub 2 sub 9 sub - sub x V sub x N sub 4 (R=Y, Ce, Nd, Sm, Gd, Tb, and Dy)

    CERN Document Server

    Han Xiu Feng; Li Qi; Zhang Mao Cai; Zhou Shou Zeng

    1998-01-01

    A systematic investigation of crystallographic and magnetic properties of nitride R sub 3 Fe sub 2 sub 9 sub - sub x V sub x N sub 4 (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy) has been performed. Nitrogenation leads to a relative volume expansion of about 6%. The lattice constants and unit cell volume decrease with increasing rare-earth atomic number from Nd to Dy, reflecting the lanthanide contraction. On average, the Curie temperature increases due to the nitrogenation to about 200 K compared with its parent compound. Generally speaking, nitrogenation also results in a remarkable improvement of the saturation magnetization and anisotropy fields at 4.2 K and room temperature for R sub 3 Fe sub 2 sub 9 sub - sub x V sub x N sub 4 compared with their parent compounds. The transition temperature indicates the spin reorientations of R sub 3 Fe sub 2 sub 9 sub - sub x V sub x N sub 4 for R Nd and Sm are at around 375 and 370 K which are higher than that of R sub 3 Fe sub 2 sub 9 sub - sub x V sub x for R = Nd and Sm 145...

  17. First-principle calculations of crystal structures, electronic structures, and optical properties of RETaO4 (RE = Y, La, Sm, Eu, Dy, Er)

    Science.gov (United States)

    Ma, Zhuang; Zheng, Jiayi; Wang, Song; Gao, Lihong

    2018-01-01

    It is an effective method to protect components from high power laser damage using high reflective materials. The rare earth tantalates RETaO4 with high dielectric constant suggests that they may have very high reflectivity, according to the relationship between dielectric constant and reflectivity. The crystal structures, electronic structures, and optical properties of RETaO4 (RE=Y, La, Sm, Eu, Dy, Er) have been studied by first-principle calculations. With the increasing atomic number of RE (i.e., the number of 4f electrons), a 4f electron shell moves from the bottom of conduction band to the forbidden gap and then to the valence band. The relationship between the electronic structures and optical properties is explored. The electron transitions among O 2p states, RE 4f states, and Ta 5d states have a key effect on optical properties such as dielectric function, absorption coefficient, and reflectivity. For the series of RETaO4, the appearance of the 4f electronic states will obviously promote the improvement of reflectivity. When the 4f states appear at the middle of the forbidden gap, the reflectivity reaches the maximum. The reflectivity of EuTaO4 at 1064 nm is up to 93.47%, indicating that it has potential applications in the antilaser radiation area.

  18. Noticeable red emission and Raman active modes in nanoscale gadolinium oxyfluoride (Gd{sub 4}O{sub 3}F{sub 6}) systems with Eu{sup 3+} inclusion

    Energy Technology Data Exchange (ETDEWEB)

    Hazarika, Samiran; Mohanta, Dambarudhar [Tezpur University, Nanoscience and Soft Matter Laboratory, Department of Physics, Tezpur, Assam (India)

    2017-05-15

    Eu{sup 3+} doped gadolinium oxyfluoride (Gd{sub 4}O{sub 3}F{sub 6}, GOF) nanoscale systems have been synthesized following a modified Pechini method. While exhibiting a tetragonal crystal structure, the GOF nanosystem gave an average crystallite size (d) of ∝21-26 nm. The Lotgering factor (L{sub F}), which is a measure of orientation of crystallites along the preferred direction was found to vary between 0.22 and 0.48. In the photoluminescence spectra, ∝595 and ∝613 nm peaks were identified as magnetically driven ({sup 5}D{sub 0} → {sup 7}F{sub 1}) and electrically driven ({sup 5}D{sub 0} → {sup 7}F{sub 2}) transitions with latter (red emission) being strongly manifested with Eu{sup 3+} doping concentration and intrinsic defects. Moreover, several Raman active modes have been probed in the Raman spectra with low frequency peaks (<300 cm{sup -1}) and moderate frequency peaks (∝481 and 567 cm{sup -1}) assigned to observable vibration of heavy atom Gd-Gd pairs and Gd-O groups, respectively. Apart from manifestation of phononic features, inclusion of Eu{sup 3+} in the host lattice would bring new insight on improving the red emission response prior to concentration quenching. (orig.)

  19. EU

    DEFF Research Database (Denmark)

    Nissen, Mogens Rostgaard

    2008-01-01

    Den Europæiske Union har som et vigtigt mål at forbedre samarbejdet mellem medlemslandene. At få udvisket betydningen af de gamle statsgrænser. Åbne grænser og større fleksibilitet skal øge den økonomiske vækst i Europa - især i grænseregionerne, der ofte er yderområder i de enkelte lande. Det...... politiske sigte er, at det tværnationale samarbejde skal øge den politiske og kulturelle samhørighed landene imellem. I det dansk-tyske grænseområde har EU gennem mange år forsøgt at medvirke til øge samarbejdet over grænsen. Der er ydet økonomisk og politisk støtte til forskellige projekter, der kan styrke...

  20. Synthesis and characterization of a heptadentate (N4O3 Schiff base ligand and associated La(III, Sm(III and Gd(III complexes, and a theoretical study

    Directory of Open Access Journals (Sweden)

    Sadegh Salehzadeh

    2010-04-01

    Full Text Available A new symmetrical potentially heptadentate (N4O3 Schiff base ligand {N[CH2CH2CH2N=CH(2-OH-5-BrC6H3]3} (H3L6 and associated neutral Gd(III, La(III and Sm(III complexes, were synthesized. The new compounds were characterized by IR spectroscopy, elemental analysis and mass spectrometry in all cases and in the case of ligand also with NMR spectroscopy. The relative capability of H3L6 to encapsulate a lanthanide ion, herein La(III, has been theoretically studied by ab initio restricted Hartree-Fock (RHF and DFT (B3LYP methods. The calculation confirmed that the H3L6 ligand can effectively encapsulate a lanthanide ion and enforce a seven-coordinate geometry.

  1. Mid-temperature deep removal of hydrogen sulfide on rare earth (RE = Ce, La, Sm, Gd) doped ZnO supported on KIT-6: Effect of RE dopants and interaction between active phase and support matrix

    Science.gov (United States)

    Li, Lu; Zhou, Pin; Zhang, Hongbo; Meng, Xianglong; Li, Juexiu; Sun, Tonghua

    2017-06-01

    Rare earth oxides (RE = Ce, La, Sm and Gd) doped ZnO supported on KIT-6 sorbents (RE-ZnO/KIT-6) were synthesized by sol-gel method and their performance for deep removal of H2S (bellow 0.1 ppmv) from gas stream at medium temperature was tested. The RE dopants (except Ce) significantly enhance the deep desulfurization capacity of ZnO/KIT-6 sorbent and maintained higher sulfur uptake capacities upon multiple cycles of regeneration by a simple thermal oxidation in 10 v% of O2 in N2 atmosphere. The results of SAXS, XRD, N2 physisorption, TEM, FIIR, and XPS implied that the KIT-6 structure of loading metal oxides remained intact. It was found that RE could hinder the ZnO crystal ripening during calcination resulted in smaller ZnO particles, enhance the interaction of ZnO and silica matrix to improve the dispersion of active phase on KIT-6. Furthermore, by increasing the outlayer electron density of Zn atom and oxygen transfer ability, the synergistic effect considered to be favorable for RE-ZnO/KIT-6 sulfidation. Even though the performance of improving ZnO dispersion was weaker than that of Sm and Gd, La-ZnO/KIT-6 performs the best deep desulfurizers by changing the surface chemical atmosphere for ZnO. Steam in the gas stream inhibited the capture of H2S by ZnO in the sorbents, in the case of La-ZnO/KIT-6, the steam content should control as lower as 5 v% to ensure the desulfurization efficiency and precision.

  2. High-pressure synthesis and magnetic behavior of A-site columnar-ordered double perovskites, LnMn(Ga{sub 0.5}Ti{sub 0.5}){sub 2}O{sub 6} (Ln = Sm, Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Shimura, Gen; Niwa, Ken; Shirako, Yuichi; Hasegawa, Masashi [Department of Crystalline Materials Science, Nagoya University, 464-8601, Nagoya (Japan)

    2017-01-26

    A-site columnar-ordered double perovskites, LnMn(Ga{sub 0.5}Ti{sub 0.5}){sub 2}O{sub 6} (Ln = Sm, Gd), were successfully synthesized under high pressure and high temperature (6 GPa, 1375 K). From the synchrotron powder X-ray diffraction patterns, all of the diffraction peaks can be indexed by the P4{sub 2}/nmc space group with lattice parameters a, c ∼ 2a{sub p} (a{sub p}: primitive cubic perovskite lattice) and no ordering of the B-site cations. Rietveld analysis of the synchrotron powder X-ray diffraction patterns and Curie-Weiss fitting of their magnetizations reveal that the ionic formulae of these perovskites are Ln{sup 3+}Mn{sup 2+}(Ga{sup 3+}{sub 0.5}Ti{sup 4+}{sub 0.5}){sub 2}O{sup 2-}{sub 6}. SmMn(Ga{sub 0.5}Ti{sub 0.5}){sub 2}O{sub 6} shows canted-antiferromagnetic behavior, whereas GdMn(Ga{sub 0.5}Ti{sub 0.5}){sub 2}O{sub 6} exhibits two different magnetic states at low temperature depending on the applied magnetic field and shows an unusual magnetization curve. These magnetic behaviors originate by decreasing the antiferromagnetic interaction by substituting Ga{sup 3+}(d{sup 10}) for Ti{sup 4+}(d{sup 0}) and by decreasing the ferromagnetic interaction between columnar-ordered Ln{sup 3+} and Mn{sup 2+}. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Synthesis and ionic conductivity of new high Li ion content garnets, LnSr{sub 2}Ta{sub 2}Li{sub 7}O{sub 12} (Ln = La, Pr, Nd, Sm, Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Howard, M.A. [School of Chemistry, University of Birmingham, Birmingham B15 2TT (United Kingdom); Clemens, O. [School of Chemistry, University of Birmingham, Birmingham B15 2TT (United Kingdom); Technische Universität Darmstadt, Joint Research Laboratory Nanomaterials, Jovanka-Bontschits-Straße 2, 64287 Darmstadt (Germany); Karlsruher Institut für Technologie, Institut für Nanotechnologie, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Parvathy, A.S. [Technische Universität Darmstadt, Joint Research Laboratory Nanomaterials, Jovanka-Bontschits-Straße 2, 64287 Darmstadt (Germany); Karlsruher Institut für Technologie, Institut für Nanotechnologie, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Anderson, P.A. [School of Chemistry, University of Birmingham, Birmingham B15 2TT (United Kingdom); Slater, P.R., E-mail: p.r.slater@bham.ac.uk [School of Chemistry, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2016-06-15

    In this paper we report the synthesis and Li ion conductivity of the new high Li content garnet phases LnSr{sub 2}Ta{sub 2}Li{sub 7}O{sub 12} (Ln = La, Pr, Nd, Sm or Gd). Close inspection of the X-ray diffraction patterns indicate that these systems are mostly composed of the ordered tetragonal garnet phase, along with a small amount of cubic garnet. The presence of a small amount of cubic garnet phase can most likely be correlated with partial Li loss on synthesis as well as some degree of H{sup +}/Li{sup +} exchange. The latter was supported by results from variable temperature X-ray diffraction studies and thermogravimetric analysis. The adoption of the tetragonal garnet structure by these new systems highlights further that in order to accommodate 7 Lithium ions within the garnet structure, then cation ordering must occur to prevent short Li–Li interactions. In line with other tetragonal garnet systems, the Li ion conductivity is shown to be low, as a result of this ordered Li distribution. - Highlights: • The successful synthesis of new LnSr{sub 2}Ta{sub 2}Li{sub 7}O{sub 12} (Ln = La, Pr, Nd, Sm, Gd) garnet phases. • The demonstration that these “Li7” garnets all adopt tetragonal symmetry consistent with Li ordering. • The demonstration that these systems are susceptible to moisture from the air, which leads to partial H/Li Exchange.

  4. Optical, Structural and Paramagnetic Properties of Eu-Doped Ternary Sulfides ALnS2 (A = Na, K, Rb; Ln = La, Gd, Lu, Y

    Directory of Open Access Journals (Sweden)

    Vítězslav Jarý

    2015-10-01

    Full Text Available Eu-doped ternary sulfides of general formula ALnS2 (A = Na, K, Rb; Ln = La, Gd, Lu, Y are presented as a novel interesting material family which may find usage as X-ray phosphors or solid state white light emitting diode (LED lighting. Samples were synthesized in the form of transparent crystalline hexagonal platelets by chemical reaction under the flow of hydrogen sulfide. Their physical properties were investigated by means of X-ray diffraction, time-resolved photoluminescence spectroscopy, electron paramagnetic resonance, and X-ray excited fluorescence. Corresponding characteristics, including absorption, radioluminescence, photoluminescence excitation and emission spectra, and decay kinetics curves, were measured and evaluated in a broad temperature range (8–800 K. Calculations including quantum local crystal field potential and spin-Hamiltonian for a paramagnetic particle in D3d local symmetry and phenomenological model dealing with excited state dynamics were performed to explain the experimentally observed features. Based on the results, an energy diagram of lanthanide energy levels in KLuS2 is proposed. Color model xy-coordinates are used to compare effects of dopants on the resulting spectrum. The application potential of the mentioned compounds in the field of white LED solid state lighting or X-ray phosphors is thoroughly discussed.

  5. Effect of oxygen annealing on magnetic performance of (Nd,Eu,Gd)Ba.sub.2./sub.Cu.sub.3./sub.O.sub.y./sub. with a lamelar pinning nanostructure

    Czech Academy of Sciences Publication Activity Database

    Jirsa, Miloš; Rameš, Michal; Muralidhar, M.; Diko, P.

    2009-01-01

    Roč. 153, č. 1 (2009), 012015/1-012015/15 ISSN 1742-6588. [International Conference On Superconductivity and Magnetism (ICSM2008). Side-Antalya, 25.08.2008–29.08.2008] R&D Projects: GA ČR GA202/08/0722 Institutional research plan: CEZ:AV0Z10100520 Keywords : (Nd,Eu,Gd)Ba 2 Cu 3 O y * annealing effect * pinning * critical currents Subject RIV: BM - Solid Matter Physics ; Magnetism

  6. Effect of lithium ion doping on cubic Gd{sub 1.88}Eu{sub 0.12}O{sub 3}: Enhancement of photoluminescence and thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yipu; Shimokawa, Yohei; Ishihara, Yasutaka [Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Miao, Lei; Tanemura, Sakae [Key Laboratory for Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Iwamoto, Yuji [Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan)

    2015-10-15

    Li{sup +}-doped cubic Gd{sub 1.88}Eu{sub 0.12}O{sub 3} powders were synthesized at 1200 °C by the solid state reaction method. Under excitation of the charge transfer band of Eu{sup 3+} at 245 nm, the Gd{sub 1.88}Eu{sub 0.12}O{sub 3} exhibited a dominant photoluminescence (PL) red emission peak at 611 nm, which is attributed to the electric dipole transition {sup 5}D{sub 0}→{sup 7}F{sub 2} of Eu{sup 3+}. The dominant PL red emission peak intensity increased with Li{sup +} doping and reached a maximum in the range from 12 to 16 mol%. This intensity was approximately 3 times higher than that of undoped Gd{sub 1.88}Eu{sub 0.12}O{sub 3}. Chemical composition analysis revealed that the Li{sup +} species was completely evaporated from the samples by the heat treatment up to 1200 °C. However, during the heat treatment at 600–1000 °C, the doped Li{sup +} could promote formation of a liquid phase, which enhanced the crystallite growth of cubic Gd{sub 1.88}Eu{sub 0.12}O{sub 3} by Ostwald ripening. The thermal stability of the cubic Gd{sub 1.88}Eu{sub 0.12}O{sub 3} was also improved with respect to the amount of Li{sup +} doping. Even after annealing at 1300 °C (higher than the cubic/monoclinic phase transformation temperature of 1250 °C) for 72 h, X-ray diffraction pattern analysis indicated that the relative fraction of the cubic phase in the 12 mol% Li{sup +}-doped sample was as high as 90%. The relationship between the amount of Li{sup +} doping and the asymmetric ratio evaluated for the PL emission spectrum and PL quantum efficiency of the cubic Gd{sub 1.88}Eu{sub 0.12}O{sub 3} samples suggested that, in addition to enhanced crystallite growth, the formation of additional oxygen vacancies promoted by Li{sup +} doping contributed to simultaneous enhancement in the PL red emission intensity and the thermal stability of cubic Gd{sub 1.88}Eu{sub 0.12}O{sub 3} investigated in this study. - Highlights: • The intensity of the Li{sup +} doped sample was 3 times higher

  7. Effects of rare-earth substitution on the stability and electronic structure of REZnOSb (RE = La-Nd, Sm-Gd) investigated via first-principles calculations

    International Nuclear Information System (INIS)

    Guo Kai; Man Zhenyong; Cao Qigao; Chen Haohong; Guo Xiangxin; Zhao Jingtai

    2011-01-01

    Graphical abstract: The structure stability of REZnOSb decreases with varying rare-earth from La to Gd because of the increased binding energy. Research highlights: → As increasing the atomic number of the RE, the structural stability of REZnOSb decreases. → Varying the rare-earth elements from La to Gd, the covalent interactions between [ZnSb] and [LaO] layer are enhanced by 4f-electrons. → The electrical transport properties of REZnOSb could be improved using the large atomic number of the RE. - Abstract: The structural stability, chemical bonding, Mulliken populations, and charge-density distribution of REZnOSb (RE = La-Nd, Sm-Gd) were investigated by first-principles calculations. Unit cell parameters calculated by the generalized gradient approximation (GGA) are in better agreement with experimental results than those derived from the local density approximation (LDA). Binding energy comparisons indicate that the structural stability of REZnOSb decreases with the increment of the atomic number of the RE, as confirmed by X-ray diffraction (XRD) results. Semimetal or narrow band-gap semiconductor behaviors are found for selected REZnOSb. Moreover, chemical bonding analysis shows that there exist considerable polar covalent interactions between the participating atoms. It also reveals that the [ZnSb] layers receive some electrons from the [LaO] layers (donor) as an electrons acceptor and holes transport tunnel. The covalent interactions between the [ZnSb] and [LaO] layers, which are enhanced by 4f-electrons of the RE, are supposed to improve the electrical transport properties.

  8. Oxalic Acid-Assisted Hydrothermal Synthesis and Luminescent of Hexagonal NaYF4:Ln3+ (Ln = Sm, Eu, Yb/Er Micro/Nanoplates

    Directory of Open Access Journals (Sweden)

    Feng Tao

    2017-01-01

    Full Text Available Hexagonal NaYF4:Ln3+ micro/nanoplates were successfully synthesized via a hydrothermal method using oxalic acid as a shape modifier. X-ray diffraction (XRD, field emission scanning electron microscopy (FE-SEM, transmission electron microscopy (TEM, and selected area electron diffraction (SAED have been used to study the morphologies and crystal structure of the products. The effects of the pH values and the molar ratio of oxalic acid to NaOH on the crystal growth have been investigated in detail. The time-dependent experiments have been conducted to investigate the morphology evolution process, and based on the results, a possible growth mechanism was proposed. The photoluminescence properties of 5 mol% Eu3+ and 3 mol% Sm3+ doped NaYF4 and 20 mol% Yb3+/2 mol% Er3+ codoped NaYF4 micro/nanoplates were investigated. The experimental results showed that NaYF4:Ln3+ micro/nanoplates have excellent luminescence and can be potential application in the field of light display systems, lasers, and optoelectronic devices.

  9. Ultralong well-aligned TiO2:Ln3+ (Ln = Eu, Sm, or Er) fibres prepared by modified electrospinning and their temperature-dependent luminescence.

    Science.gov (United States)

    Yu, Hongquan; Li, Yue; Song, Yang; Wu, Yanbo; Lan, Xijie; Liu, Shimin; Tang, Yanning; Xu, Shasha; Chen, Baojiu

    2017-03-07

    Electrospinning has emerged as an attractive technique for the fabrication of ultrafine fibres in micro-/nano-scale fineness: however, it remains a significant technological challenge to assemble aligned fibre arrays via an conventional electrospinning method due to the inherent whipping instability of the polymeric jet. We herein have first developed a simple modified electrospinning method with which to prepare ultralong (>300 mm) well-aligned inorganic fibre arrays, i.e., using an ultrahigh molecular weight polymer to suppress or eliminate the whipping motion of the electrospun jet, has emerged as a facile approach for the continuous fabrication of well-aligned, ultralong fibres through simply using a rotating cylinder as the collector (it was not found necessary to use a very high rotating speed, extra magnetic, electrical field) in the electrospinning process. As result, the ultralong well-aligned TiO 2 :Ln 3+ (Ln = Eu, Sm, or Er) fibre arrays can be obtained from ultrahigh molecular weight poly(ethylene oxide), tetra-n-butyl titanate (Ti(OC 4 H 9 ) 4 ) and lanthanide nitrate in the modified electrospinning approach. The grow mechanism and luminescent properties of these ultralong well-aligned TiO 2 :Ln 3+ fibre arrays were also investigated.

  10. Synthesis of New RE3+ Doped Li1+xTa1−xTixO3 (RE: Eu, Sm, Er, Tm, and Dy Phosphors with Various Emission Colors

    Directory of Open Access Journals (Sweden)

    Hiroyuki Hayashi

    2013-07-01

    Full Text Available New phosphors with various emission colors for RE3+ doped Li1+xTa1−xTixO3 (LTT (RE: Eu, Sm, Er, Tm, and Dy were synthesized by electric furnace at 1423 K for 15 h. The microstructure of the host material and the photoluminescence (PL property were determined and compared to those of RE3+ doped Li1+xNb1−xTixO3 (LNT. In the LTT phosphor, the highest PL intensity was achieved for the mixture composition Li1.11Ta0.89Ti0.11O3 with a LiTaO3 structure, although it has an M-phase superstructure. In the LTT host material, the effective activators were Eu3+ and Sm3+ ions, in contrast to the LNT host material. Here, we discuss the relationship between PL property and the host material’s structure.

  11. Synthetic and spectroscopic studies of vanadate glaserites II: Photoluminescence studies of Ln:K{sub 3}Y(VO{sub 4}){sub 2} (Ln=Eu, Er, Sm, Ho, or Tm)

    Energy Technology Data Exchange (ETDEWEB)

    Kimani, Martin M., E-mail: kimani@g.clemson.edu; McMillen, Colin D., E-mail: cmcmill@g.clemson.edu; Kolis, Joseph W., E-mail: kjoseph@clemson.edu

    2015-03-15

    Glaserite-type potassium yttrium double vanadates (K{sub 3}Y(VO{sub 4}){sub 2}) doped with Eu{sup 3+}, Er{sup 3+}, Sm{sup 3+}, Ho{sup 3+}, or Tm{sup 3+} have been synthesized by solid state reactions at 1000 °C for 48 h and their photoluminescence properties investigated. Efficient energy transfer from the vanadate group to the rare earth ion has been established by photoluminescence investigation. Ultraviolet excitation into the metal to ligand charge transfer band of the vanadate groups results in orange-red, blue and green emissions from Eu{sup 3+} (592 nm), Sm{sup 3+} (602 nm), Tm{sup 3+} (475 nm), Er{sup 3+} (553 nm), and Ho{sup 3+} (541–551 nm) dopant ions. The emission intensities of the lanthanide-doped K{sub 3}Y(VO{sub 4}){sub 2} powders were studied as a function of dopant ion concentrations. Over the concentration ranges studied, no emission quenching was observed for Eu{sup 3+} or Ho{sup 3+} dopants, while Er{sup 3+}, Sm{sup 3+} and Tm{sup 3+} dopants did exhibit such effects for dopant ion concentrations greater than 5%, probably due to cross relaxation processes. - Graphical abstract: Synthesis and photoluminescence in vanadate glaserites. - Highlights: • K{sub 3}Y(VO{sub 4}){sub 2} doped with Eu, Er, Tm, Sm, or Ho were synthesized via solid-state reactions. • Photoluminescence properties are investigated. • The lanthanide doped K{sub 3}Y(VO{sub 4}){sub 2} compounds revealed efficient energy transfer from the vanadate group to the rare earth ions. • The presented compounds are promising materials for light display systems, lasers, and optoelectronic devices.

  12. Uncovering the Origin of Divergence in the CsM(CrO4)2(M = La, Pr, Nd, Sm, Eu; Am) Family through Examination of the Chemical Bonding in a Molecular Cluster and by Band Structure Analysis.

    Science.gov (United States)

    Galley, Shane S; Arico, Alexandra A; Lee, Tsung-Han; Deng, Xiaoyu; Yao, Yong-Xin; Sperling, Joseph M; Proust, Vanessa; Storbeck, Julia S; Dobrosavljevic, Vladimir; Neu, Jennifer N; Siegrist, Theo; Baumbach, Ryan E; Albrecht-Schmitt, Thomas E; Kaltsoyannis, Nikolas; Lanatà, Nicola

    2018-02-07

    A series of f-block chromates, CsM(CrO 4 ) 2 (M = La, Pr, Nd, Sm, Eu; Am), were prepared revealing notable differences between the Am III derivatives and their lanthanide analogs. While all compounds form similar layered structures, the americium compound exhibits polymorphism and adopts both a structure isomorphous with the early lanthanides as well as one that possesses lower symmetry. Both polymorphs are dark red and possess band gaps that are smaller than the Ln III compounds. In order to probe the origin of these differences, the electronic structure of α-CsSm(CrO 4 ) 2 , α-CsEu(CrO 4 ) 2 , and α-CsAm(CrO 4 ) 2 were studied using both a molecular cluster approach featuring hybrid density functional theory and QTAIM analysis and by the periodic LDA+GA and LDA+DMFT methods. Notably, the covalent contributions to bonding by the f orbitals were found to be more than twice as large in the Am III chromate than in the Sm III and Eu III compounds, and even larger in magnitude than the Am-5f spin-orbit splitting in this system. Our analysis indicates also that the Am-O covalency in α-CsAm(CrO 4 ) 2 is driven by the degeneracy of the 5f and 2p orbitals, and not by orbital overlap.

  13. Photoreduction of Sm3+ to Sm2+ in alcoholic solution

    International Nuclear Information System (INIS)

    Kusaba, M.; Tsunawaki, Y.; Nakashima, N.

    1998-01-01

    Full text: Lanthanide ions in solution display broad and sharp absorption bands in the UV and near UV to near IR spectral regions, respectively. The former bands are called charge-transfer (CT) or 5d 3+ , Eu 3+ and Sm 3+ . Furthermore, the photoreduction of Eu 3+ is taken place via an f' 3+ to Sm 2+ because the photoproduct, Sm 2+ , is unstable in the solution. Donohue added macrocyclic ether, 18-crown-6, to the solution in order to stabilize the Sm 2+ and then suggested the photoreduction of Sm 3+ to Sm 2+ would be induced by a multi-photon process. In this work, the transient absorption spectra of Sm 2+ has been measured by means of a nanosecond laser flash photolysis in order to clarify the photoreduction process of Sm 3+ to Sm 2+ in more detail. A sample containing a concentration of 0.01 M Sm 3+ was prepared by adding a slightly stoichiometric excess of 18-crown-6 to a methanol solution of SmCl 3 .6H 2 O. It was completely degassed by freeze-pump-thaw cycles on a high vacuum line to avoid oxidation of Sm 2+ by dissolved oxygen. The flash photolysis measurements were carried out at room temperature. The linear dependence of the concentration of Sm 2+ on the laser fluence indicated that the photoreduction of Sm 3+ to Sm 2+ in the solution occurs via the one-photon process. The photoreduction yield of Sm 3+ was determined to be 0.34 Angstroms ± 0. 09. The lifetime of Sm 2+ in air saturated sample was estimated to be 4.6 micro second

  14. Complexation of amidocarbamoyl phosphine oxides with Ln+3 (Ln = La, Nd, Pm, Sm and Eu) cation series: structural and thermodynamical features

    International Nuclear Information System (INIS)

    Hosseinnejad, Tayebeh; Kazemi, Tayebeh

    2016-01-01

    In the present study, we have mainly investigated the nature of interactions in Ln 3+ (Ln = La, Nd, Pm, Sm, Eu) complexes with amidocarbamoyl methyl phosphine oxide (CMPO) and amidocarbamoyl propyl phosphine oxide (CPPO) ligands based on density functional theory (DFT) approaches. In the first step, thermodynamical properties for complexation of CMPO and CPPO ligands with Ln 3+ cation series have been determined in the gas phase and with the presence of three solvents: n-hexane, chloroform and toluene, via polarized continuum model (PCM) computations. The trend of metal-ligand interaction strength has been analyzed and compared with the trend of ionic hardness within the series of lanthanide cations and different size of alkyl chain of amidocarbamoyl phosphine oxide ligand. The calculated thermochemical results in the gas and solution phases reveals that there is a consistency between increasing trend in the hardness of Ln 3+ cation series and also electron-donating property of alkyl chain with increasing in thermodynamical stability of [Ln-CMPO] 3+ and [Ln-CPPO] 3+ complex series. We have also demonstrated that in the complexation reaction of all complex series, using n-hexane as solvent is more favorable thermodynamically than chloroform and toluene. It should be stated that this issue has been observed in many experiments. Finally, analysis of calculated deformation energies and also the variation in bond order of some selected key bonds in CMPO and CPPO ligands and their corresponded Ln 3+ complexes series show a similar trend with increasing in the hardness of Ln 3+ cation series and electron-donating of alkyl chain of amidocarbamoyl phosphine oxide ligand.

  15. Synthesis, structural characterization, luminescent properties and theoretical study of three novel lanthanide metal-organic frameworks of Ho(III), Gd(III) and Eu(III) with 2,5-thiophenedicarboxylate anion

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Lippy F. [Instituto de Química, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20550-013 (Brazil); Correa, Charlane C. [Departamento de Química-ICE, Universidade Federal de Juiz de Fora, Juiz de Fora-MG, 36036-330 (Brazil); Ribeiro, Sidney J.L.; Santos, Molíria V. dos [Institute of Chemistry, São Paulo State University − UNESP, CP 355 Araraquara-SP 14801-970 Brazil (Brazil); Dutra, José Diogo L.; Freire, Ricardo O. [Pople Computational Chemistry Laboratory, Departamento de Química, Universidade Federal de Sergipe, São Cristóvão-SE 49100-000 (Brazil); Machado, Flávia C., E-mail: flavia.machado@ufjf.edu.br [Departamento de Química-ICE, Universidade Federal de Juiz de Fora, Juiz de Fora-MG, 36036-330 (Brazil)

    2015-07-15

    In this paper, the synthesis of three new metal-organic frameworks of lanthanides (LnMOFs) ([Ln{sub 2}(2,5-tdc){sub 3}(dmso){sub 2}]·H{sub 2}O){sub n} (Ln=Ho (1); Gd (2); Eu (3); 2,5-tdc=2,5-thiophenedicarboxylate anion; dmso=dimethylsulfoxide), and their complete characterization, including single crystal X-ray diffraction, FTIR spectroscopy and thermogravimetric analysis are reported. In especial, photophysical properties of Eu(III) complex have been studied in detail via both theoretical and experimental approaches. Crystal structure of (1) reveals that each lanthanide ion is seven-coordinated by oxygen atoms in an overall distorted capped trigonal – prismatic geometry. The 2,5-tdc{sup 2−} ligands connect four Ln(III) centers, adopting (κ{sup 1}–κ{sup 1})–(κ{sup 1}–κ{sup 1})–μ{sub 4} coordination mode, generating an 8-connected uninodal 3D network. In addition, theoretical studies for Eu(III) complex were performed using the Sparkle model for lanthanide complexes. - Graphical abstract: Three new metal-organic frameworks of lanthanides (LnMOFs) ([Ln{sub 2}(2,5-tdc){sub 3}(dmso){sub 2}]·H{sub 2}O){sub n} (Ln=Ho (1); Gd (2); Eu (3); 2,5-tdc=2,5-thiophenedicarboxylate anion; dmso=dimethylsulfoxide), were synthesized and their complete characterization, including single crystal X-ray diffraction, FTIR spectroscopy and thermogravimetric analysis are reported. In especial, photophysical properties of Eu(III) complex have been studied in detail via both theoretical and experimental approaches. - Highlights: • Three new LnMOFs were synthesized and fully characterized. • Ho{sup 3+}, Gd{sup 3+} and Eu{sup 3+} complexes photoluminescence properties were investigated. • Theoretical approaches for Eu{sup 3+} complex luminescence has been performed. • An energy level diagram is used to establish the ligand-to-metal energy transfer. • These metal−organic frameworks can act as light conversion molecular devices.

  16. Hydrothermal synthesis and photoluminescent properties of hierarchical GdPO4·H2O:Ln3+ (Ln3+ = Eu3+, Ce3+, Tb3+) flower-like clusters

    Science.gov (United States)

    Amurisana, Bao.; Zhiqiang, Song.; Haschaolu, O.; Yi, Chen; Tegus, O.

    2018-02-01

    3D hierarchical GdPO4·H2O:Ln3+ (Ln3+ = Eu3+, Ce3+, Tb3+) flower clusters were successfully prepared on glass slide substrate by a simple, economical hydrothermal process with the assistance of disodium ethylenediaminetetraacetic acid (Na2H2L, where L4- = (CH2COO)2N(CH2)2N(CH2COO)24-). In this process, Na2H2L was used as both a chelating agent and a structure-director. The hierarchical flower clusters have an average diameter of 7-12 μm and are composed of well-aligned microrods. The influence of the molar ratio of Na2H2L/Gd3+ and reaction time on the morphology was systematically studied. A possible crystal growth and formation mechanism of hierarchical flower clusters is proposed based on the evolution of morphology as a function of reaction time. The self-assembled GdPO4·H2O:Ln3+ superstructures exhibit strong orange-red (Eu3+, 5D0 → 7F1), green (Tb3+, 5D4 → 7F5) and near ultraviolet emissions (Ce3+, 5d → 7F5/2) under ultraviolet excitation, respectively. This study may provide a new channel for building hierarchically superstructued oxide micro/nanomaterials with optical and new properties.

  17. Mid-temperature deep removal of hydrogen sulfide on rare earth (RE = Ce, La, Sm, Gd) doped ZnO supported on KIT-6: Effect of RE dopants and interaction between active phase and support matrix

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lu; Zhou, Pin; Zhang, Hongbo; Meng, Xianglong; Li, Juexiu; Sun, Tonghua, E-mail: sunth@sjtu.edu.cn

    2017-06-15

    Highlights: • Various rare earth (RE)-doped ZnO/KIT-6 sorbents were prepared via sol-gel method. • La showed the highest efficiency on promoting ZnO/KIT-6 desulfurization activity. • The morphology of ZnO on KIT-6 played a crucial role for the reactivity. • The most initial factor of improving reactivity by RE was surface chemical property. • Crystallinity, host-guest interaction were also important to ZnO state on support. - Abstract: Rare earth oxides (RE = Ce, La, Sm and Gd) doped ZnO supported on KIT-6 sorbents (RE-ZnO/KIT-6) were synthesized by sol-gel method and their performance for deep removal of H{sub 2}S (bellow 0.1 ppmv) from gas stream at medium temperature was tested. The RE dopants (except Ce) significantly enhance the deep desulfurization capacity of ZnO/KIT-6 sorbent and maintained higher sulfur uptake capacities upon multiple cycles of regeneration by a simple thermal oxidation in 10 v% of O{sub 2} in N{sub 2} atmosphere. The results of SAXS, XRD, N{sub 2} physisorption, TEM, FIIR, and XPS implied that the KIT-6 structure of loading metal oxides remained intact. It was found that RE could hinder the ZnO crystal ripening during calcination resulted in smaller ZnO particles, enhance the interaction of ZnO and silica matrix to improve the dispersion of active phase on KIT-6. Furthermore, by increasing the outlayer electron density of Zn atom and oxygen transfer ability, the synergistic effect considered to be favorable for RE-ZnO/KIT-6 sulfidation. Even though the performance of improving ZnO dispersion was weaker than that of Sm and Gd, La-ZnO/KIT-6 performs the best deep desulfurizers by changing the surface chemical atmosphere for ZnO. Steam in the gas stream inhibited the capture of H{sub 2}S by ZnO in the sorbents, in the case of La-ZnO/KIT-6, the steam content should control as lower as 5 v% to ensure the desulfurization efficiency and precision.

  18. Power-law index and penetration depth of (NdxSmxGd1−2x)Ba2Cu3O7−δ films studied by AC susceptibility

    DEFF Research Database (Denmark)

    Li, Xiaofen; He, Dong; Grivel, Jean-Claude

    2012-01-01

    Superconducting (NdxSmxGd1−2x)Ba2Cu3O7−δ films with x=0, 0.1, 0.25, 0.33 were grown by PLD on STO single crystal substrates. The power-law index n and penetration depth λ are studied by AC susceptibility. During cooling, n in films with x ≠ 0 increases much slower compared with the films with x =....... The films with x ≠ 0 also tend to have a longer penetration depth. These properties might be related to the higher possibility for disorder in the mixed (Nd,Sm,Gd)BCO films....

  19. The effect of co-dopant addition on the properties of Ln{sub 0.2}Ce{sub 0.8}O{sub 2-{delta}} (Ln = Gd, Sm, La) solid-state electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Pikalova, E.Yu.; Demina, A.N.; Demin, A.K. [Institute of High Temperature Electrochemistry, 22 S. Kovalevskoy, 620219 Ekaterinburg (Russian Federation); Maragou, V.I.; Tsiakaras, P.E. [School of Engineering, Department of Mechanical Engineering, University of Thessaly, Pedion Areos, 383 34 Volos (Greece)

    2008-07-01

    The present work aims at the investigation of Ln{sub 0.2}Ce{sub 0.8}O{sub 2-{delta}} (where Ln = Sm, La, Gd) structural and electrical properties when in the Ln sub-lattice, Ba{sup 2+} and Sr{sup 2+} with ionic radii 1.42 and 1.26 Aa, respectively, are introduced. The conductivity measurements were held both in air and in H{sub 2} + 3%H{sub 2}O atmosphere using the 4-probe dc technique at the temperature range of 600-900 C. Among all the samples, the highest value of electrical conductivity is obtained in the case of (Sm{sub 0.75}Sr{sub 0.2}Ba{sub 0.05}){sub 0.2}Ce{sub 0.8}O{sub 2-{delta}}, both in air and in hydrogen atmosphere. In the case of H{sub 2} + 3%H{sub 2}O the conductivity of the co-doped compounds increases in comparison with air. Moreover, the dependence of conductivity on the oxygen partial pressure, measured at the P{sub O{sub 2}} range of 0.21-10{sup -22} atm, showed that the electrolytic area of alkaline-earth metals doped Ln{sub 0.2}Ce{sub 0.8}O{sub 2-{delta}} is considerably enhanced, as predicted by the theory. Finally, by comparing the thermal expansion coefficients of the different materials (TEC), the thermo-mechanical compatibility between the co-doped and the other cell components was also investigated. (author)

  20. Structure and Chemical Bonding of the Li-Doped Polar Intermetallic RE2In1−xLixGe2 (RE = La, Nd, Sm, Gd; x = 0.13, 0.28, 0.43, 0.53 System

    Directory of Open Access Journals (Sweden)

    Junsu Lee

    2018-03-01

    Full Text Available Four polar intermetallic compounds belonging to the RE2In1−xLixGe2 (RE = La, Nd, Sm, Gd; x = 0.13(1, 0.28(1, 0.43(1, 0.53(1 system have been synthesized by the traditional solid-state reaction method, and their crystal structures have been characterized by single-crystal X-ray diffraction (SXRD analyses. The isotypic crystal structures of four title compounds adopt the Mo2FeB2-type structure having the tetragonal space group P4/mbm (Z = 2, Pearson code tP40 with three crystallographically independent atomic sites and can be simply described as a pile of the identical 2-dimensioanl (2D RE2In1-xLixGe2 slabs stacked along the c-axis direction. The substituting Li atom shows a particular site preference for replacing In at the Wyckoff 2a site rather than Ge at the Wyckoff 4g in this crystal structure. As the size of a used rare-earth metal decreases from La3+ to Gd3+ throughout the title system, the Ge-Ge and Ge-In/Li bond distances, both of which consist of the 2D anionic Ge2(In/Li layer, gradually decrease resulting in the reduction of a unit cell volume. A series of theoretical investigations has been performed using a hypothetical structure model Gd2In0.5Li0.5Ge2 by tight-binding linear muffin-tin orbital (TB-LMTO method. The resultant densities of states (DOS value at the Fermi level (EF suggests a metallic conductivity for this particular composition, and this calculation result is in a good agreement with the formal charge distribution assigning two extra valence electrons for a metal-metal bond in the conduction band. The thorough analyses of six crystal orbital Hamilton population (COHP curves representing various interatomic interactions and an electron localization function (ELF diagram indicating the locations of paired-electron densities are also provided in this article.

  1. Excess of Eu in the(Nd.sub.0.33./sub.Eu.sub.0.33+x./sub.Gd.sub.0.33-x./sub.)Ba.sub.2./sub.Cu.sub.3./sub.O.sub.y./sub. system: the way to a high irreversibility field at 77 K

    Czech Academy of Sciences Publication Activity Database

    Muralidhar, M.; Sakai, N.; Wu, Y.; Murakami, M.; Jirsa, Miloš; Nishizaki, T.; Kobayashi, N.

    2002-01-01

    Roč. 15, - (2002), s. 1357-1363 ISSN 0953-2048 R&D Projects: GA AV ČR IAA1010919 Institutional research plan: CEZ:AV0Z1010914 Keywords : melt-textured superconductor s * (Nd, Eu, Gd)Ba 2 Cu 3 O y * secondary phase particles * pinning defects * irreversibility field Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.138, year: 2002

  2. Theoretical and experimental spectroscopic studies of the first highly luminescent binuclear hydrocinnamate of Eu(III), Tb(III) and Gd(III) with bidentate 2,2'-bipyridine ligand

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Lippy F.; Correa, Charlane C.; Garcia, Humberto C. [Departamento de Química-ICE, Universidade Federal de Juiz de Fora, Juiz de Fora-MG 36036-330 (Brazil); Martins Francisco, Thiago [Departamento de Física-ICEx, Universidade Federal de Minas Gerais, Pampulha, Belo Horizonte-MG 30123-970 (Brazil); Ribeiro, Sidney J.L. [Instituto de Química, Universidade Estadual Paulista Júlio de Mesquita Filho-UNESP, CP 355, Araraquara-SP 14801-970 (Brazil); Dutra, José Diogo L.; Freire, Ricardo O. [Pople Computational Chemistry Laboratory, Departamento de Química, Universidade Federal de Sergipe, São Cristóvão-SE 49100-000 (Brazil); Machado, Flávia C., E-mail: flavia.machado@ufjf.edu.br [Departamento de Química-ICE, Universidade Federal de Juiz de Fora, Juiz de Fora-MG 36036-330 (Brazil)

    2014-04-15

    In this paper, the synthesis of three new binuclear lanthanide (III) complexes [Ln{sub 2}(cin){sub 6}(bpy){sub 2}] (Ln=Eu (1), Tb (2), Gd (3), cin=hydrocinnamate anion; bpy=2,2'-bipyridine), and their complete characterization, including single crystal X-ray diffraction, FTIR spectroscopy and thermal analysis (TGA/DTA) are reported. In especial, photophysical properties of Eu(III) complex have been studied in detail via both theoretical and experimental approaches. Crystal structures of 1–3 reveal that all compounds are isostructural and that each lanthanide ion is nine-coordinated by oxygen and nitrogen atoms in an overall distorted tricapped trigonal-prismatic geometry. Eu(III) complex structure was also calculated using the Sparkle model for lanthanide complexes and the intensity parameters (Ω{sub 2}, Ω{sub 4}, and Ω{sub 6}), calculated from the experimental data and from Sparkle/PM3 model. The theoretical emission quantum efficiencies obtained for Sparkle/PM3 structures are in excellent agreement with the experimental values, clearly attesting to the efficacy of the theoretical models. The theoretical procedure applied here shows that the europium binuclear compound displays a quantum yield about 65% suggesting that the system can be excellent for the development of efficient luminescent devices. Highlights: • First binuclear Ln{sup 3+}-hydrocinnamate have been synthesized and characterized. • Eu{sup 3+}, Tb{sup 3+} and Gd{sup 3+} complexes photoluminescence properties were investigated. • Theoretical approaches for Eu{sup 3+} complex luminescence has been performed. • An energy level diagram is used to establish the ligand-to-metal energy transfer. • 65% Quantum yield suggests an excellent system for luminescent devices.

  3. Dynamics of the lattice and spins in the phase-separated manganite (Eu{sub 1−x}Gd{sub x}){sub 0.6}Sr{sub 0.4}MnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Haruka, E-mail: tanig@iwate-u.ac.jp [Department of Physical Science and Materials Engineering, Iwate University, Morioka 020-8551 (Japan); Kimura, Daichi; Matsukawa, Michiaki; Inomata, Tasuku; Kobayashi, Satoru [Department of Physical Science and Materials Engineering, Iwate University, Morioka 020-8551 (Japan); Nimori, Shigeki [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Suryanarayanan, Ramanathaan [Laboratoire de Physico-Chimie de l’Etat Solide, CNRS, UMR8182, Université Paris-Sud, 91405 Orsay (France)

    2017-06-15

    We investigated slow relaxations of the magnetostriction and residual magnetostriction of the phase-separated system (Eu{sub 1−x}Gd{sub x}){sub 0.6}Sr{sub 0.4}MnO{sub 3}, in which the metamagnetic transition from a paramagnetic insulating state to a ferromagnetic metallic state is accompanied by a lattice shrinkage. The relaxations are well fitted by a stretched exponential function, suggesting the strong frustration between the double exchange interaction and Jahn-Teller effect. We have revealed that the Gd substitution suppresses the frozen phase-separated phase at low temperatures and stabilizes the paramagnetic insulating state in the dynamic phase-separated phase at intermediate temperatures. The former origin would be the randomness effect and the latter would be the suppression of the double exchange interaction.

  4. Cu k-edge studies of the charge carries in Th-doped cuprate system R2-xThxCuO4-δ (R = Nd, Sm and Gd)

    International Nuclear Information System (INIS)

    Liang, G.; Yi, Y.; Jardim, R.F.; Wang, L.V.

    1999-01-01

    To further study the charge carrier concentration in electron doped cuprate superconductors, a systematic x-ray absorption near edge structure (XANES) measurement has been carried out on Th-doped superconductor system R 2-x Th x CuO 4-δ (R = Nd, Sm, and Gd). The XANES results show that, similar to the Ce-doped compounds, while the intensity of the Cu 1+ 4p π feature increase with the increase of the Th doping level x, the intensities of the Cu 2+ 4p π and 4p σ features decreases. This clearly indicates that the electrons doped by the Th atoms are injected into the local Cu 3d-orbitals. The normalized Cu 1+ 4p π intensity data show that the Cu 1+ concentration in the Th-doped compound series with different R-elements is linearly proportional to the Th doping-level x. The data suggest that both Ce and Th donate the same fraction of electrons into the Cu sites

  5. Effect of lanthanide on the microstructure and structure of LnMn0.5Fe0.5O3 nanoparticles with Ln=La, Pr, Nd, Sm and Gd prepared by the polymer precursor method

    International Nuclear Information System (INIS)

    Romero, Mariano; Faccio, Ricardo; Martínez, Javier; Pardo, Helena; Montenegro, Benjamín; Plá Cid, Cristiani Campos; Pasa, André A.

    2015-01-01

    The synthesis of LnMn 0.5 Fe 0.5 O 3 perovskite nanoparticles by the polymer precursor method showed a strong intrinsic dependence with different lanthanides (Ln=La, Pr, Nd, Sm and Gd). The polymerization level reached in the polymer precursor was proportional to the atomic number of lanthanide with exception of samarium, which showed the formation of a different precursor based in a citrate chelate with ethyleneglycol bonded as adduct. The increasing level of polymerization of the polymer precursors showed the formation of large-size perovskite nanoparticles after its calcination. SAXS and TEM analyses suggested that nanoparticles obtained, using this method, have a squared-like microstructure in connection with the polymer precursor microstructure. Structural analysis showed an orthorhombic structure with a slight decline in the Jahn–Teller distortion when the atomic number of lanthanide increases. Mössbauer spectroscopy showed the presence of a majority site in agreement with the Pbnm orthorhombic structure best fitted with Rietveld refinements and in some cases, a more distorted site attributed to local inhomogeneities and oxygen vacancies. - Highlights: • Precursor polymerization level is lower in the presence of lighter lanthanides. • Lighter lanthanide perovskite nanoparticles after calcination are lower-sized. • Nanoparticles obtained by this method have lamellae microstructure. • Jahn–Teller distortion declines for heavier lanthanide perovskites. • Oxygen vacancy phase was observed in lighter lanthanide perovskites

  6. Matrix chemical ratio and its optimization for highest flux pinning in ternary (Nd-Eu-Gd)Ba.sub.2./sub.Cu.sub.3./sub.O.sub.y./sub..

    Czech Academy of Sciences Publication Activity Database

    Muralidhar, M.; Jirsa, Miloš; Sakai, N.; Murakami, M.

    2002-01-01

    Roč. 15, - (2002), s. 688-693 ISSN 0953-2048. [International Workshop on Processing and Application of Superconducting (RE) BCO Large Grain Materials /3./. Seatle, 11.07.2001-13.07.2001] R&D Projects: GA AV ČR IAA1010919 Institutional research plan: CEZ:AV0Z1010914 Keywords : (Nd-Eu-Gd)Ba 2 Cu 3 O y * flux pinning * irreversibility field * pinning defects Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.138, year: 2002

  7. Sol-gel syntheses of pentaborate β-LaB5O9 and the photoluminescence by doping with Eu3+, Tb3+, Ce3+, Sm3+, and Dy3+

    Science.gov (United States)

    Yang, Ruirui; Sun, Xiaorui; Jiang, Pengfei; Gao, Wenliang; Cong, Rihong; Yang, Tao

    2018-02-01

    Rare earth (RE) borates have been extensively studied as good photoluminescent materials, however, the target hosts were limited to "RE3BO6", REBO3, and REB3O6 in the RE2O3-B2O3 phase diagram until the recent discovery of rare earth pentaborate. For the first time, the sol-gel method was employed to synthesize β-LaB5O9 doped with Eu3+, Tb3+, Ce3+, Sm3+, Dy3+. In comparison to the previous synthetic methods, the sol-gel method possesses superiorities including easily-controllable doping concentration, high yield and emission efficiency. Solid solutions of phosphors were prepared and carefully analyzed by powder X-ray diffraction. Concentration quenching or saturation was observed in Eu3+, Tb3+ and Ce3+ doped phosphors at round 10 at%. Eu3+, Tb3+, Sm3+, and Dy3+ emit red, green, orange, and close-to-white light, respectively. The absolute emission efficiency of Ce3+ is high and in the UV range, suggesting the function of being sensitizer once combined with other activators.

  8. Mass of the 158Sm

    International Nuclear Information System (INIS)

    Zhao Kui; Guo Jiyu; Lu Xiuqin; Cheng Yehao; Huang Xiaolin; Ma Yong; Li Shuyuan; Ruan Ming; Li Zhichang; Jiang Chenglie

    1997-01-01

    A preliminary result was reported for the experiment to determine the mass of the heavier neutron-rich nucleus 158 Sm using the 160 Gd( 18 O, 20 Ne) two proton transfer reaction in last progress report. The average Q-value of (4.046 +- 0.102) MeV for the 160 Gd( 18 O, 20 Ne) 158 Sm reaction is given. A mass excess for 158 Sm of (-65.738 +- 0.102) MeV was derived. This is the first experimentally measured value of the mass of 158 Sm which is about 450 keV higher than the evaluation value from systematic trends listed in the 1993 atomic mass table. The new prediction shows better agreement with the measured values and a significant improvement over the earlier FRDM (finite-range droplet model) value

  9. A facile approach to synthesize SiO2???Re2O3 (Re?=?Y, Eu, La, Sm, Tb, Pr) hollow sphere and its application in drug release

    OpenAIRE

    Li, Zhihua; Zhu, Lin; Liu, Qian; Du, Yu; Wang, Feng

    2013-01-01

    Multifunctional SiO2???Re2O3 (Re?=?Y, Eu, La, Sm, Tb, Pr) hollow spheres (HSs) have been fabricated using an acidic Re3+ ion solution. Under ultraviolet radiation, functional HSs emit different colors of light according to the different rare-earth ions embedded into the shell of SiO2 hollow spheres. The as-prepared hollow capsules were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller method, scanning...

  10. A facile approach to synthesize SiO2 · Re2O3 (Re = Y, Eu, La, Sm, Tb, Pr) hollow sphere and its application in drug release

    Science.gov (United States)

    Li, Zhihua; Zhu, Lin; Liu, Qian; Du, Yu; Wang, Feng

    2013-10-01

    Multifunctional SiO2 · Re2O3 (Re = Y, Eu, La, Sm, Tb, Pr) hollow spheres (HSs) have been fabricated using an acidic Re3+ ion solution. Under ultraviolet radiation, functional HSs emit different colors of light according to the different rare-earth ions embedded into the shell of SiO2 hollow spheres. The as-prepared hollow capsules were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller method, scanning electron microscopy, and energy-dispersive spectrometry. Drug loading and release experiments have been carried out using SiO2 · Eu2O3 HSs that acted as drug carriers. The results demonstrate that the multifunctional HSs exhibit a high storage capacity and the ability of retaining drug stability and activity, which indicates that the as-synthesized fluorescent hollow capsules are a potential candidate as drug delivery materials.

  11. Luminescence characteristics of undoped and Eu-doped GdCa.sub.4./sub.O(BO.sub.3./sub.).sub.3./sub. single crystals and nanopowders

    Czech Academy of Sciences Publication Activity Database

    Solarz, P.; Nikl, Martin; Klos, A.; Lisiecki, R.; Ryba-Romanowski, W.; Rzepka, A.; Ganschow, S.; Pajaczkowska, A.

    2007-01-01

    Roč. 42, č. 12 (2007), s. 1308-1313 ISSN 0232-1300 R&D Projects: GA MŠk(CZ) 1M06002 Institutional research plan: CEZ:AV0Z10100521 Keywords : VUV * energy transfer * luminiscence * GdCOB Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.768, year: 2007

  12. High-Precision Measurement of Eu/Eu* in Geological Glasses via LA-ICP-MS Analysis

    Science.gov (United States)

    Tang, Ming; McDonough, William F.; Arevalo, Ricardo, Jr.

    2014-01-01

    Elemental fractionation during laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis has been historically documented between refractory and volatile elements. In this work, however, we observed fractionation between light rare earth elements (LREEs) and heavy rare earth elements (HREEs) when using ablation strategies involving large spot sizes (greater than 100 millimeters) and line scanning mode. In addition: (1) ion yields decrease when using spot sizes above 100 millimeters; (2) (Eu/Eu*)(sub raw) (i.e. Europium anomaly) positively correlates with carrier gas (He) flow rate, which provides control over the particle size distribution of the aerosol reaching the ICP; (3) (Eu/Eu*)(sub raw) shows a positive correlation with spot size, and (4) the changes in REE signal intensity, induced by the He flow rate change, roughly correlate with REE condensation temperatures. The REE fractionation is likely driven by the slight but significant difference in their condensation temperatures. Large particles may not be completely dissociated in the ICP and result in preferential evaporation of the less refractory LREEs and thus non-stoichiometric particle-ion conversion. This mechanism may also be responsible for Sm-Eu-Gd fractionation as Eu is less refractory than Sm and Gd. The extent of fractionation depends upon the particle size distribution of the aerosol, which in turn is influenced by the laser parameters and matrix. Ablation pits and lines defined by low aspect ratios produce a higher proportion of large particles than high aspect ratio ablation, as confirmed by measurements of particle size distribution in the laser induced aerosol. Therefore, low aspect ratio ablation introduces particles that cannot be decomposed and/or atomized by the ICP and thus results in exacerbated elemental fractionation. Accurate quantification of REE concentrations and Eu/Eu* requires reduction of large particle production during laser ablation. For the reference

  13. Selective detection of Fe{sup 3+}, Cr{sup 3+} and Cu{sup 2+} in water using highly luminescent Gd{sub 2}O{sub 3}:Eu{sup 3+} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Debasish [Chemical Engineering and Process Development Division, National Chemical Laboratory, Pune 411008 (India); Luwang, Meitram Niraj, E-mail: mn.luwang@ncl.res.in [Chemical Engineering and Process Development Division, National Chemical Laboratory, Pune 411008 (India); Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, Rafi Marg, New Delhi 110001 (India)

    2016-03-15

    Rod shaped Eu{sup 3+} doped Gd{sub 2}O{sub 3} nanoparticles were synthesised by a simple wet-chemical method followed by high temperature heating at 700 °C. The nanoparticles were characterised by X-ray diffraction (XRD), infra-red (IR), transmission electron microscopy (TEM), x-ray photonelectron spectroscopy (XPS), photoluminescence (PL) studies and lifetime measurement. The particles show strong host sensitised luminescence in water. Luminescence in water is selectively quenched by Fe{sup 3+}, Cr{sup 3+} and Cu{sup 2+} ions. This luminescence quenching phenomenon has been utilised to detect metal ions in synthetic water and environmental water samples. Results obtained by luminescence quenching for environmental water samples are in good agreement with the results obtained from inductively coupled plasma atomic emission spectroscopy (ICP-AES) study.

  14. Comparative magnetic studies of (Sm, Nd) trichloroacetates and their heteronuclear CuLn2(CCl3COO)8.6H2O systems: structure and spectroscopy of a new type of Eu trichloroacetate

    International Nuclear Information System (INIS)

    Wojciechowski, W.; Legendziewicz, J.; Puchalska, M.; Ciunik, Z.

    2004-01-01

    Two series of compounds: heteronuclear CuLn 2 (CCl 3 COO) 8 .6H 2 O (Ln = Nd and Sm) and their simple analogues Ln(CCl 3 COO) 3 .2H 2 O (Ln = Eu, Nd, Sm) were synthesized. New Eu(III) trichloroacetate; Eu(CCl 3 COO) 3 .3H 2 O.CH 3 OH was obtained, its molecular structure was determined by X-ray diffraction and compared with the data of respective systems reported earlier. Magnetization was measured and the susceptibility was derived in the limit of low field. Magnetic susceptibilities were calculated and discussed for series of homo- and hetero-nuclear chloroacetates.Untypical hysteresis was found (two loops) in samarium trichloroacetate. This phenomenon is most probably the effect of flops of spins in magnetic fields of 30,000Oe and very weak (if any) interaction intermediated by weak hydrogen bonding between the chains. A similar magnetic behavior was observed in neodymium carboxylate where the magnetic ordering was observed as a result of Nd-Nd interaction at low temperature (1.6K). For this system, the magnetic moment depends on magnitude of the magnetic field and ferromagnetic ordering appears at low temperatures. The strongest interactions of coupled ions and antiferromagnetic ordering with T N =6.5K were found in CuSm 2 (CCl 3 COO) 8 .6H 2 O single crystals.Heisenberg model was applied in the calculations for three interacting ions located linearly. The following relation was derived: χ M =Ng 2 μ β 2 kT(12)+(12)exp(J 2 /kT)+5exp(J 2 /kT)-exp(1,5J 1 /kT)2+2exp(J 2 /kT)+4exp(J 2 /kT)-exp(1,5J 1 /kT) and applied in calculations of the exchange integrals. Mechanism of the exchange interaction was discussed on the basis of the obtained results.

  15. Preparation and studies of Eu{sup 3+} and Tb{sup 3+} co-doped Gd{sub 2}O{sub 3} and Y{sub 2}O{sub 3} sol-gel scintillating films

    Energy Technology Data Exchange (ETDEWEB)

    Morales Ramirez, A. de J, E-mail: amoralesra@ipn.m [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada (CICATA) Unidad Altamira Instituto Politecnico Nacional Km. 14.5 Carr. Tampico-Puerto Industrial, C.P. 89600, Altamira, Tamaulipas (Mexico); Depto. de Ingenieria Metalurgica, ESIQIE-Instituto Politecnico Nacional UPALM C.P. 07738, Mexico D.F. (Mexico); Garcia Murillo, A.; Carrillo Romo, F. de J [Depto. de Ingenieria Metalurgica, ESIQIE-Instituto Politecnico Nacional UPALM C.P. 07738, Mexico D.F. (Mexico); Ramirez Salgado, J. [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas No. 152, CP 07730, Mexico D.F. (Mexico); Le Luyer, C. [LPCML, CNRS-UMR 5620/Universite Claude Bernard Lyon 1/69622 Villeurbanne Cedex (France); Chadeyron, G.; Boyer, D. [Laboratoire des Materiaux Inorganiques, CNRS-UMR 6002, Universite Blaise Pascal, 24 Ave des Landais F 63177 Aubiere Cedex (France); Moreno Palmerin, J. [Depto. de Ingenieria Metalurgica, ESIQIE-Instituto Politecnico Nacional UPALM C.P. 07738, Mexico D.F. (Mexico)

    2009-10-30

    Eu{sup 3+} (2.5 at.%) and Tb{sup 3+} (0.005-0.01 at.%) co-doped gadolinium and yttrium oxide (Gd{sub 2}O{sub 3} and Y{sub 2}O{sub 3}) powders and films have been prepared using the sol-gel process. High density and optical quality thin films were prepared with the dip-coating technique. Gadolinium (III) 2,4-pentadionate and yttrium (III) 2,4-pentadionate were used as precursors, and europium and terbium in their nitrate forms were used as doping agents. Chemical and structural analyses (infrared spectroscopy, X-ray diffraction and high-resolution transmission electron microscopy) were conducted on both sol-gel precursor powders and dip-coated films. The morphology of thin films heat-treated at 700 {sup o}C was studied by means of atomic force microscopy. It was shown that the highly dense and very smooth films had a root mean roughness (RMS) of 2 nm {+-} 0.2 (A = 0.0075 Tb{sup 3+}) and 24 nm {+-} 3.0 (B = 0.01 Tb{sup 3+}). After treatment at 700 {sup o}C, the crystallized films were in the cubic phase and presented a polycrystalline structure made up of randomly oriented crystallites with grain sizes varying from 20 to 60 nm. The X-ray induced emission spectra of Eu{sup 3+}- and Tb{sup 3+}-doped Gd{sub 2}O{sub 3} and Y{sub 2}O{sub 3} powders showed that Tb{sup 3+} contents of 0.005, 0.0075 and 0.01 at.% affected their optical properties. Lower Tb{sup 3+} concentrations (down to 0.005 at.%) in both systems enhanced the light yield.

  16. Implantation sites of Ce and Gd in diamond

    CERN Document Server

    Bharuth-Ram, K; Hofsäss, H C; Ronning, C; Dietrich, M

    2002-01-01

    The implantation sites of rare earth (RE) probes /sup 141/Ce (t/sub 1 /2/=32 d) and /sup 149/Gd (t/sub 1/2/=9.28 d) in diamond have been investigated using the emission channeling (EC) technique. Parent isotopes /sup 141/Cs and /sup 149/Dy were implanted into type IIa, diamond samples at an energy of 60 keV at the online isotope separator ISOLDE at CERN. /sup 141/Cs decays through the chain /sup 141/Cs-/sup 141/Ba-/sup 141/La-/sup 141/Ce-/sup 141/ Pr. EC measurements were made on the 102 keV conversion electrons emitted in the decay of /sup 141/Pr to its ground state. The decay of /sup 149 /Dy follows the chain /sup 149/Dy-/sup 149/Tb-/sup 149/Gd-/sup 149 /Eu-/sup 149/Sm. EC measurements were made on the 101 keV electrons emitted in the decay of /sup 149/Eu. Two-dimensional channeling patterns of the conversion electrons were obtained along and axial directions by raster scans with a Si surface barrier detector. Comparison of the observed patterns with simulated spectra show that in diamond 45-50% of the RE...

  17. Preparation and characterization of electroluminescent devices based on complexes of {beta}-diketonates of Tb{sup 3+}, Eu{sup 3+}, Gd{sup 3+} ions with macrocyclic ligands and UO{sub 2}{sup 2+} films; Preparacao e caracterizacao de dispositivos eletroluminescentes de complexos de {beta}-dicetonados de ions Tb{sup 3+}, Eu{sup 3+}, Gd{sup 3+} com ligantes macrociclicos e filmes de UO{sub 2}{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Gibelli, Edison Bessa

    2010-07-01

    Complexes containing Rare Earth ions are of great interest in the manufacture of electro luminescent devices as organic light emitting devices (OLED). These devices, using rare earth trivalent ions (TR{sup 3+}) as emitting centers, show high luminescence with extremely fine spectral bands due to the structure of their energy levels, long life time and high quantum efficiency. This work reports the preparation of Rare Earth {beta}-diketonate complexes (Tb{sup 3+}, Eu{sup 3+} and Gd{sup 3+}) and (tta - thenoyltrifluoroacetonate and acac - acetylacetonate) containing a ligand macrocyclic crown ether (DB18C6 - dibenzo18coroa6) and polymer films of UO{sub 2}{sup 2+}. The materials were characterized by complexometric titration with EDTA, CH elemental analysis, near infrared absorption spectroscopy, thermal analysis, X-ray diffraction (powder method) and luminescence spectroscopy. For manufacturing the OLED it was used the technique of deposition of thin films by physical vapor (PVD, Physical Vapor Deposition). (author)

  18. Highly-luminescent Eu,Sm,Mn-doped CaS up/down conversion nano-particles: application to ultra-sensitive latent fingerprint detection and in vivo bioimaging.

    Science.gov (United States)

    Wang, Jikai; He, Ni; Zhu, Yanli; An, Zhengbin; Chen, Ping; Grimes, Craig A; Nie, Zhou; Cai, Qingyun

    2018-01-16

    Due to their unique properties, rare-earth doped upconversion luminescence (UCL) nanomaterials are of considerable scientific interest. Meanwhile, alkaline-earth sulfide materials based on a completely different electron trapping (ET) mechanism demonstrate extremely high UCL efficiencies, which are several dozens of times more than those of conventional fluoride UCL nanomaterials. However, the large particle size, easy hydrolysis, and difficulty in achieving uniform dispersion have precluded bioassay applications. Herein, we have synthesized super-bright Eu,Sm,Mn-doped CaS nanoparticles of ∼30 nm average particle size using a reverse microemulsion technique. The UCL quantum yield was up to nearly 60%. Modification of the nanoparticles with an organic layer allows their stable dispersion throughout aqueous solutions without significant loss of the fluorescence intensity. We demonstrate the application of the novel UCL materials to latent fingerprint detection, deep tissue imaging, and in vivo bioimaging.

  19. Structural Characterization and Absolute Luminescence Efficiency Evaluation of Gd2O2S High Packing Density Ceramic Screens Doped with Tb3+ and Eu3+ for further Applications in Radiology

    Science.gov (United States)

    Dezi, Anna; Monachesi, Elenasophie; D'Ignazio, Michela; Scalise, Lorenzo; Montalto, Luigi; Paone, Nicola; Rinaldi, Daniele; Mengucci, Paolo; Loudos, George; Bakas, Athanasios; Michail, Christos; Valais, Ioannis; Fountzoula, Christine; Fountos, George; David, Stratos

    2017-11-01

    Rare earth activators are impurities added in the phosphor material to enhance probability of visible photon emission during the luminescence process. The main activators employed are rare earth trivalent ions such as Ce+3, Tb+3, Pr3+ and Eu+3. In this work, four terbium-activated Gd2O2S (GOS) powder screens with different thicknesses (1049 mg/cm2, 425.41 mg/cm2, 313 mg/cm2 and 187.36 mg/cm2) and one europium-activated GOS powder screen (232.18 mg/cm2) were studied to investigate possible applications for general radiology detectors. Results presented relevant differences in crystallinity between the GOS:Tb doped screens and GOS:Eu screens in respect to the dopant agent present. The AE (Absolute efficiency) was found to rise (i) with the increase of the X-ray tube voltage with the highest peaking at 110kVp and (ii) with the decrease of the thickness among the four GOS:Tb. Comparing similar thickness values, the europium-activated powder screen showed lower AE than the corresponding terbium-activated.

  20. Spectroscopic study of Eu{sup 3+}-doped Gd{sub 1-x}Y{sub x}Ca{sub 4}O(BO{sub 3}){sub 3} prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Klos, A. [Institute of Electronic Materials Technology, 133 Wolczynska Street, 01919 Warszawa (Poland)], E-mail: Andrzej.Klos@itme.edu.pl; Lipinska, L. [Institute of Electronic Materials Technology, 133 Wolczynska Street, 01919 Warszawa (Poland); Solarz, P.; Ryba-Romanowski, W. [Institute of Low Temperature and Structure Research, Polish Academy of Science, 2 Okolna Street, 50-950 Wroclaw (Poland)

    2008-07-14

    Eu{sup 3+}-doped Gd{sub 1-x}Y{sub x}Ca{sub 4}O(BO{sub 3}){sub 3} solid solutions in the form of nanopowders with mean particle size of about 50 nm were prepared by sol-gel method for x = 0.13, 0.44 and 0.60. X-ray examination revealed that compounds prepared by this method are single phase in contrast to compounds prepared by solid state reaction. Room temperature VUV-UV excitation spectra of the {sup 5}D{sub 0} emission and corresponding VUV-excited emission spectra of Eu{sup 3+} were recorded using synchrotron radiation. In addition the excitation spectra in the visible region and the {sup 5}D{sub 0} luminescence decay curves were measured. Spectroscopic features of nanopowders prepared by sol-gel method were compared with those evaluated for single crystal samples grown by the micro-pulling down technique from charge prepared by sol-gel method. It has been concluded that the sol-gel method facilitates the control of stoichiometry and structural stability of compounds under study.

  1. A facile approach to synthesize SiO2 · Re2O3 (Re = Y, Eu, La, Sm, Tb, Pr) hollow sphere and its application in drug release.

    Science.gov (United States)

    Li, Zhihua; Zhu, Lin; Liu, Qian; Du, Yu; Wang, Feng

    2013-10-21

    Multifunctional SiO2 · Re2O3 (Re = Y, Eu, La, Sm, Tb, Pr) hollow spheres (HSs) have been fabricated using an acidic Re3+ ion solution. Under ultraviolet radiation, functional HSs emit different colors of light according to the different rare-earth ions embedded into the shell of SiO2 hollow spheres. The as-prepared hollow capsules were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller method, scanning electron microscopy, and energy-dispersive spectrometry. Drug loading and release experiments have been carried out using SiO2 · Eu2O3 HSs that acted as drug carriers. The results demonstrate that the multifunctional HSs exhibit a high storage capacity and the ability of retaining drug stability and activity, which indicates that the as-synthesized fluorescent hollow capsules are a potential candidate as drug delivery materials.

  2. Spectral and CIE parameters of red emitting Gd{sub 3}Ga{sub 5}O{sub 12}:Eu{sup 3+} phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.K., E-mail: sksharma.ism@gmail.com; Som, S., E-mail: sudipta.som@gmail.com; Jain, R.; Kunti, A.K.

    2015-03-15

    This paper reports the structural, spectral and photometric parameters of Eu{sup 3+} doped gadolinium gallium garnet (GGG) phosphor synthesized by combustion synthesis method and post annealed at three different temperatures. The XRD studies show the lattice formation of GGG phosphor with body centered cubic structure. Rietveld refinement and analytical calculation of different structural parameters were performed to get the idea about the rare earth substitution in host matrix. The band gap of the phosphor was calculated from diffuse reflectance spectra using the Kubelka–Munk function. The characteristic red luminescence corresponding to {sup 5}D{sub 0}→{sup 7}F{sub J} (J=1, 2) transitions of Eu{sup 3+} was observed after irradiation with UV light. The various analytical parameters such as Judd–Ofelt intensity, spectral and CIE were estimated from the photoluminescence data. - Highlights: • Rietveld refinement result indicates the rare earth substitution in host matrix. • Spectroscopic investigation of Eu{sup 3+} in gadolinium gallium garnet host. • CIE parameters and purity indicate its suitability in lighting technology.

  3. Luminescent SiO 2-coated Gd 2O 3:Eu 3+ nanorods/poly(styrene) nanocomposites by in situ polymerization

    Science.gov (United States)

    Macedo, Andreia G.; Martins, Manuel A.; Fernandes, Sílvia E. M.; Barros-Timmons, Ana; Trindade, Tito; Carlos, Luís D.; Rocha, João

    2010-10-01

    Europium doped gadolinium oxide nanorods have been coated with silica via a sol-gel approach. The silica coating increases the Eu 3+ absolute emission quantum yields from 0.51 to 0.86 (255 nm excitation) and decay times from 1.43 to 1.80 ms (394.4 nm excitation). Subsequently the silica coating was modified with 3-(trimethoxysilyl)-propyl-methacrylate. Grafting of silica with the MPS coupling agent was confirmed by FTIR and contact angle measurements. The functionalized nanoparticles were used as core structures in the in situ radical polymerization of styrene via miniemulsion and solution routes. Depending on the polymerization technique used the morphology of the polymer coating consisted in isolated spheres or a homogenous film respectively. Although the optical properties of the ensuing nanocomposites were reduced the synthetic strategy developed to process this type of luminescent nanoparticles proved efficient and can be explored using different vinyl or (meth)acrylate monomers.

  4. Síntesis y Evaluación de las Propiedades de Nanopartículas de Gd2O3 Dopadas con Centros Luminiscentes de Eu mediante Spray Pirolisis

    Directory of Open Access Journals (Sweden)

    Milosevic, O.

    2006-04-01

    Full Text Available Influence of the Eu3+ luminescence center concentration on the structural, morphological and spectroscopic properties of the powders obtained in accordance to the aerosol method was studied in this work. The processing route includes aerosol formation ultrasonically (resonant frequency 1.7MHz from common gadolinium and europium nitrate solutions and control over the aerosol decomposition in a high-temperature (up to 1473K tubular flow reactor. During decomposition, the aerosol droplets undergo evaporation/drying, precipitation and thermolysis in a dispersed phase and in a single-step process. Consequently, spherical, solid, agglomerate-free, submicron-sized particles with the crystallite sizes below 20nm were obtained. In order to control the particles crystal structure and to establish the conditions for the stabilization of the lowtemperature gadolinia cubic phase, the process parameters like synthesis temperature, droplet/particle residence time and annealing temperatures were adopted. The particle morphology, phase and chemical structure were revealed in accordance to various analysis methods (XRD, SEM and EDS. Structural changes (crystallite size and microstrains after powders thermal treatment were carried out using Koalariet-XFit program as the profile-matching tools. The results obtained and the mechanisms of ultrafine phosphor particles generation were discussed in terms of precursor chemistry, process parameters and luminescence properties.En este trabajo se presentan los resultados de la influencia de la concentración de centros luminiscentes de Eu3+ en cuanto a los cambios estructurales, morfológicos y propiedades ópticas de nanopartículas de Gd2O3 obtenidas mediante técnicas de aerosol. Se ha estudiado la influencia de parámetros experimentales durante el proceso de síntesis (temperatura, caudal del gas portador, tiempo de residencia de las gotas de aerosol en el interior del horno, temperatura del horno y temperaturas isot

  5. Optical study of GeO{sub 2}-PbO-PbF{sub 2} oxyfluoride glass singly doped with Pr{sup 3+}, Nd{sup 3+}, Sm{sup 3+} and Eu{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Klimesz, B. [Physical Laboratory, Opole Technical University, ul. Ozimska 75, 45-370 Opole (Poland)]. E-mail: basiak@po.opole.pl; Dominiak-Dzik, G. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okolna 2, 50-395 WrocIaw (Poland); Solarz, P. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okolna 2, 50-395 WrocIaw (Poland); Z-dot elechower, M. [Department of Material Science, Silesian University of Technology, ul. Krasinskiego 8, 40-019 Katowice (Poland); Ryba-Romanowski, W. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okolna 2, 50-395 WrocIaw (Poland)

    2005-11-10

    Glasses with composition 50GeO{sub 2}-(50 - x)PbO-5PbF{sub 2}-xLnF{sub 3} (Ln = Pr{sup 3+}, Nd{sup 3+}, Sm{sup 3+}, Eu{sup 3+}) were synthesised in the bulk form. The content of PbF{sub 2} was constant and amounted to 5 mol% whereas, the concentration of luminescent ions was 0.2 and 2 mol%. Spectroscopic properties (absorption, emission) of optically active ions were studied at room temperature. Oscillator strengths have been used to calculate phenomenological intensity parameters {omega} {sub 2,4,6}. Radiative transition probabilities as well as branching ratios and radiative lifetimes of luminescent levels were estimated. Lifetimes and the fluorescence dynamics were studied as a function of concentration. The Judd-Ofelt analysis and the Inokuti-Hirayama model for energy transfer between activator ions provided information on radiative processes and non-radiative relaxation of excited states.

  6. Technological development for half-life measurement of 146Sm nuclide

    International Nuclear Information System (INIS)

    Kinoshita, N.; Hashimoto, T.; Nakanishi, T.

    2007-01-01

    Techniques for the measurement of the 146 Sm nuclide, which is known as an extinct nuclide on the present Earth, were developed in order to determine its half-life. The nuclide was produced in three reactions of 147 Sm(γ,n) 146 Sm, 147 Sm(n,2n) 146 Sm, and 147 Sm(p,2n) 146 Eu(→ 146 Sm). The Sm fraction in the target was chromatographically purified to prepare α counting samples as hydroxide. The 146 Sm/ 147 Sm α-activity ratios in the samples were measured using a Si surface barrier detector. The 146 Sm 22+ / 152 Sm 23+ and 147 Sm 22+ / 152S m 23+ ratios were measured by accelerator mass spectrometry using the ECR-ATLAS-GFM system. The 146 Sm ions were distinguished clearly from the other ions such as the abundant isobar, 146 Nd in the samples. (author)

  7. A novel fluorescent probe (dtpa-bis(cytosine)) for detection of Eu(III) in rare earth metal ions

    Science.gov (United States)

    Yang, Fan; Ren, Peipei; Liu, Guanhong; Song, Youtao; Bu, Naishun; Wang, Jun

    2018-03-01

    In this paper, a novel fluorescent probe, dtpa-bis(cytosine), was designed and synthesized for detecting europium (Eu3 +) ion. Upon addition of Eu3 + ions into the dtpa-bis(cytosine) solution, the fluorescence intensity can strongly be enhanced. Conversely, adding other rare earth metal ions, such as Y3 +, Ce3 +, Pr3 +, Nd3 +, Sm3 +, Gd3 +, Tb3 +, Dy3 +, Ho3 +, Er3 +, Yb3 + and Lu3 +, into dtpa-bis(cytosine) solution, the fluorescence intensity is decreased slightly. Some parameters affecting the fluorescence intensity of dtpa-bis(cytosine) solution in the presence of Eu3 + ions were investigated, including solution pH value, Eu3 + ion concentration and interfering substances. The detection mechanism of Eu3 + ion using dtpa-bis(cytosine) as fluorescent probe was proposed. Under optimum conditions, the fluorescence emission intensities of EuIII-dtpa-bis(cytosine) at 375 nm in the concentration range of 0.50 × 10- 5 mol • L- 1-5.00 × 10- 5 mol • L- 1 of Eu3 + ion display a better linear relationship. The limit of detection (LOD) was determined as 8.65 × 10- 7 mol • L- 1 and the corresponding correlation coefficient (R2) of the linear equation is 0.9807. It is wished that the proposed method could be applied for sensitively and selectively detecting Eu3 + ion.

  8. Ternary gallides RE{sub 4}Rh{sub 9}Ga{sub 5}, RE{sub 5}Rh{sub 12}Ga{sub 7} and RE{sub 7}Rh{sub 18}Ga{sub 11} (RE=Y, La-Nd, Sm, Gd, Tb). Intergrowth structures with MgCu{sub 2} and CaCu{sub 5} related slabs

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Stefan; Rodewald, Ute C.; Poettgen, Rainer [Univ. Muenster (Germany). Inst. fuer Anorganische und Analytische Chemie; Janka, Oliver [Univ. Oldenburg (Germany). Inst. fuer Chemie

    2017-07-01

    Fourteen ternary gallides RE{sub 4}Rh{sub 9}Ga{sub 5}, RE{sub 5}Rh{sub 12}Ga{sub 7} and RE{sub 7}Rh{sub 18}Ga{sub 11} (RE=Y, La-Nd, Sm, Gd, Tb) were synthesized from the elements by arc-melting, followed by different annealing sequences either in muffle or induction furnaces. The samples were characterized through Guinier powder patterns and the crystal structures of Ce{sub 4}Rh{sub 9}Ga{sub 5}, Ce{sub 5}Rh{sub 12}Ga{sub 7}, Ce{sub 7}Rh{sub 18}Ga{sub 11}, Nd{sub 5}Rh{sub 10.44(4)}Ga{sub 8.56(4)}, Nd{sub 4}Rh{sub 9}Ga{sub 5} and Gd{sub 4}Rh{sub 9}Ga{sub 5} were refined from single crystal X-ray diffractometer data. The new gallides are the n=2, 3 and 5 members of the RE{sub 2+n} Rh{sub 3+3n} Ga{sub 1+2n} structure series in the Parthe intergrowth concept. The slabs of these intergrowth structures derive from the cubic Laves phase MgCu{sub 2} (Mg{sub 2}Ni{sub 3}Si as ternary variant) and CaCu{sub 5} (CeCo{sub 3}B{sub 2} as ternary variant). Only the Nd{sub 5}Rh{sub 10.44(4)}Ga{sub 8.56(4)} crystal shows Rh/Ga mixing within the Laves type slabs. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y{sub 4}Rh{sub 9}Ga{sub 5} and Curie-Weiss paramagnetism for Gd{sub 4}Rh{sub 9}Ga{sub 5} and Tb{sub 4}Rh{sub 9}Ga{sub 5}. Low-temperature data show ferromagnetic ordering at T{sub C}=78.1 (Gd{sub 4}Rh{sub 9}Ga{sub 5}) and 55.8 K (Tb{sub 4}Rh{sub 9}Ga{sub 5}).

  9. Strongly coupled band in 140Gd

    International Nuclear Information System (INIS)

    Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N.

    2005-01-01

    Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, Kπ = 8 - isomers, with lifetimes ranging from ns to ms, are known in 128 Xe, 130 Ba, 132 Ce, 134 Nd, 136 Sm, and 138 Gd[. In 140 Gd, we have observed for the first time a band also based on an Iπ = 8 - state. This could be the first case of a Kπ = 8 - state observed in an N=76 even-even isotope. The systematics of the Kπ = 8 - isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The 140 Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in 140 Gd

  10. 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

  11. Cu3Sm(WO4)3-Sm2(WO4)3 system

    International Nuclear Information System (INIS)

    Arzumanyan, G.A.

    1982-01-01

    Vast regions (up to 25 mol%) of the existence of limited solid solutions with Dalton compositions Cu 3 Sm(WO 4 ) 3 , Cu 13 Sm 7 x(WO 4 ) 17 , Cu 9 Sm 11 (WO 4 ) 21 and Cu 3 Sm 17 (WO 4 ) 27 possessing the structures related to scheelite distorted monoclinic structure of Eu 2 (WO 4 ) 3 A-phase were revealed in the Cu 3 Sm(WO 4 ) 3 -Sm 2 (WO 4 ) 3 system at 500-1100 deg C temperatures and oxigen partial pressure of 0.9-1.3 Pa (total pressure of the noble gas - 102.1+-0.6 kPa)

  12. Narrowing the gap: from semiconductor to semimetal in the homologous series of rare-earth zinc arsenides RE(2-y)Zn4As4·n(REAs) and Mn-substituted derivatives RE(2-y)Mn(x)Zn(4-x)As4·n(REAs) (RE = La-Nd, Sm, Gd).

    Science.gov (United States)

    Lin, Xinsong; Tabassum, Danisa; Mar, Arthur

    2015-12-14

    A homologous series of ternary rare-earth zinc arsenides, prepared by reactions of the elements at 750 °C, has been identified with the formula RE(2-y)Zn4As4·n(REAs) (n = 2, 3, 4) for various RE members. They adopt trigonal structures: RE(4-y)Zn4As6 (RE = La-Nd), space group R3̄m1, Z = 3; RE(5-y)Zn4As7 (RE = Pr, Nd, Sm, Gd), space group P3̄m1, Z = 1; RE(6-y)Zn4As8 (RE = La-Nd, Sm, Gd), space group R3̄m1, Z = 3. The Zn atoms can be partially substituted by Mn atoms, resulting in quaternary derivatives RE(2-y)Mn(x)Zn(4-x)As4·n(REAs). Single-crystal structures were determined for nine ternary and quaternary arsenides RE(2-y)M4As4·n(REAs) (M = Mn, Zn) as representative examples of these series. The structures are built by stacking close-packed nets of As atoms, sometimes in very long sequences, with RE atoms occupying octahedral sites and M atoms occupying tetrahedral sites, resulting in an intergrowth of [REAs] and [M2As2] slabs. The recurring feature of all members of the homologous series is a sandwich of [M2As2]-[REAs]-[M2As2] slabs, while rocksalt-type blocks of [REAs] increase in thickness between these sandwiches with higher n. Similar to the previously known related homologous series REM(2-x)As2·n(REAs) which is deficient in M, this new series RE(2-y)M4As4·n(REAs) exhibits deficiencies in RE to reduce the electron excess that would be present in the fully stoichiometric formulas. Enthalpic and entropic factors are considered to account for the differences in site deficiencies in these two homologous series. Band structure calculations indicate that the semiconducting behaviour of the parent n = 0 member (with CaAl2Si2-type structure) gradually evolves, through a narrowing of the gap between valence and conduction bands, to semimetallic behaviour as the number of [REAs] blocks increases, to the limit of n = ∞ for rocksalt-type REAs.

  13. Studies on Structural and Morphological Properties of Multidoped Ceria Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095O2-δ (x=0.2 as Solid Solutions

    Directory of Open Access Journals (Sweden)

    Marija Stojmenović

    2016-01-01

    Full Text Available The nanopowdery solid solutions of multidoped ceria Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095O2-δ (x=0.2 with the fluorite type crystal structure of CeO2 were synthesized for the first time. Two synthesis procedures were applied: the modified glycine-nitrate procedure (MGNP method and room temperature self-propagating reaction (SPRT method. All nanopowders were characterized by XRPD analysis, Raman spectroscopy, low temperature nitrogen physisorption, TEM, and SEM methods. According to the XRPD and Raman spectroscopy results, single phase solid solutions of fluorite structure were evidenced regardless of the number of dopants and synthesis procedure. Both XRPD and TEM were analyses evidenced nanometer particle dimensions. The SPRT method results in obtaining sample with higher specific surface area, smaller crystallite and particles sizes, and the same values of the lattice parameter in comparison to pure CeO2. Raman spectroscopy was confirmed to the oxygen vacancies introduced into the ceria lattice when Ce4+ ions were replaced with cations (dopants of lower valence state (3+, which may indicate the potential improvement of ionic conductivity. Additionally, the presence of oxygen vacancies in the lattice ceria, as well as very developed grain boundaries, gives a new possibility for potential application of obtained nanopowders in the area of room temperature ferromagnetism as spintronics.

  14. Studies on Structural and Morphological Properties of Multidoped Ceria Ce 0.8 Nd 0.0025 Sm 0.0025 Gd 0.005 Dy 0.095 Y 0.095 O 2 - δ ( x = 0.2 ) as Solid Solutions

    KAUST Repository

    Stojmenović, Marija

    2016-04-17

    The nanopowdery solid solutions of multidoped ceria Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095 () with the fluorite type crystal structure of CeO2 were synthesized for the first time. Two synthesis procedures were applied: the modified glycine-nitrate procedure (MGNP method) and room temperature self-propagating reaction (SPRT method). All nanopowders were characterized by XRPD analysis, Raman spectroscopy, low temperature nitrogen physisorption, TEM, and SEM methods. According to the XRPD and Raman spectroscopy results, single phase solid solutions of fluorite structure were evidenced regardless of the number of dopants and synthesis procedure. Both XRPD and TEM were analyses evidenced nanometer particle dimensions. The SPRT method results in obtaining sample with higher specific surface area, smaller crystallite and particles sizes, and the same values of the lattice parameter in comparison to pure CeO2. Raman spectroscopy was confirmed to the oxygen vacancies introduced into the ceria lattice when Ce4+ ions were replaced with cations (dopants) of lower valence state (3+), which may indicate the potential improvement of ionic conductivity. Additionally, the presence of oxygen vacancies in the lattice ceria, as well as very developed grain boundaries, gives a new possibility for potential application of obtained nanopowders in the area of room temperature ferromagnetism as spintronics.

  15. Fokus på små selskaber

    DEFF Research Database (Denmark)

    Neville, Mette

    1997-01-01

    Nationalt såvel som internationalt er små selskaber med begrænset ansvar (anpartsselskaber) begyndt at påkalde sig opmærksomhed. I mange EU-medlemsstater, herunder Danmark søges lovgivningen i disse år tilpasset de små virksomheder behov. Dette sker i erkendelse af, at den eksisterende selskabslo...

  16. Structural studies of type N superconductive compounds: R2-xCexCuO4±δ (R = Gd, Eu, Sm, Nd, Pr); influences of chemical treatments on physical properties

    International Nuclear Information System (INIS)

    Vigoureux, P.

    1995-06-01

    Different chemical treatments of R 2-x Ce x CuO 4±δ compounds monocrystals (gadolinium, europium, samarium, neodymium and praseodymium cuprates) modify their physical properties especially their superconductive properties. The presented chemical treatments are: the substitution of the trivalent rare earth element R by an other trivalent lanthanide, its substitution by tetravalent cerium, and heat treatment under low oxygen pressure. After these chemical treatments, structural modifications are observed by neutrons and X-rays diffraction, and allow to precise their actions: size effect of the rare earth element on the deformation of the CuO 2 planes, links between deformation and superconductivity and magnetic properties. (A.B.)

  17. Degradation of high temperature superconductors of the composition R1Ba2Cu3O7 in water vapours (R = Nd, Sm, Eu, Gd, Dy, Ho, Er and Y)

    International Nuclear Information System (INIS)

    Levin, M.I.; Eremenko, Z.V.; Sakharov, M.V.; Titov, A.A.

    1991-01-01

    The effect of atoms of the rare-earth metals (REM) on the properties of the HTSC crystals (R 1 Ba 2 Cu 3 O 7 ), intrinsic to the lattice, is shown. A dependence of the degradation rate of HTSC in water vapours on the type of REM, present in the crystal structure, is found. The factors and the stages, limiting the rate of the degradation of HTSC properties, are indicated. A scheme of the mechanism of interaction of HTSC of RBaCuO 7 composition with water vapours is suggested

  18. Study of quantitative analysis of rare earth elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) in soil samples by inductively couple plasma mass spectrometry

    International Nuclear Information System (INIS)

    Truong Duc Toan; Nguyen Giang; Vo Tran Quang Thai; Do Tam Nhan; Nguyen Le Anh; Nguyen Viet Duc; Luong Thi Tham; Truong Thi Phuong Mai

    2015-01-01

    Method for the determination of 16 rare earth elements (REEs) in soil samples without separating by inductively coupled plasma mass spectrometry (ICP-MS) has been studied at Dalat Nuclear Research Institute. The optimal conditions for ICP-MS NexION 300X with three modes: Standard, Collision (KED), and Reaction (DRC) have been studied on the Montana II soil reference material. The result analysis shows that: DRC mode only gives good analysis result for Sc, Y, La, Ce, Pr, Nd, Tm, Yb, and Lu; Standard mode exhibits good analysis results for all elements with error from 1.2 - 29.0% and KED mode is the best one with error less than 15%. The concentrations of elements in the soil samples of Cau Dat, Bao Loc, and Da Lat were determined, which concentrations of REEs in soil samples of Cau Dat are higher than that of the other areas in Lam Dong Province. (author)

  19. Long-wave UVA radiation excited warm white-light emitting NaGdTiO{sub 4}: Tm{sup 3+}/Dy{sup 3+}/Eu{sup 3+} ions tri-doped phosphors: Synthesis, energy transfer and color tunable properties

    Energy Technology Data Exchange (ETDEWEB)

    Bharat, L. Krishna; Du, Peng; Yu, Jae Su, E-mail: jsyu@khu.ac.kr

    2016-05-05

    NaGdTiO{sub 4} (NGT) phosphors doped with different activator ions (Tm{sup 3+}, Dy{sup 3+}, and Eu{sup 3+}) were synthesized by a conventional solid-state reaction method in an ambient atmosphere. These phosphors were characterized by scanning electron microscope images, transmission electron microscope images, X-ray diffraction patterns, Fourier transform infrared spectra, and photoluminescence spectra. All the samples were crystallized in an orthorhombic phase with a space group of Pbcm (57). In Tm{sup 3+}/Dy{sup 3+} ions co-doped samples, white-light emission was observed under near-ultraviolet (NUV) excitation. In addition, the energy transfer between Tm{sup 3+} and Dy{sup 3+} ions was proved to be a resonant type via an electric dipole–dipole mechanism and the critical distance of energy transfer was calculated to be 19.91 Å. Furthermore, Tm{sup 3+}/Dy{sup 3+}/Eu{sup 3+} ions tri-doped NGT phosphors demonstrated warm white-light emission by appropriately tuning the activator content, based on the principle of energy transfer. These NUV wavelength excitable phosphors exhibit great potential as a single-phase full-color emitting phosphor for white light-emitting diode applications. - Highlights: • The pebble shaped NaGdTiO{sub 4} particles were prepared by solid-state reaction method. • Tm{sup 3+} and Dy{sup 3+} single doping gives respective blue and cool white light emission. • The Tm{sup 3+}/Dy{sup 3+} ions co-doped samples give CIE values near to standard white light. • Addition of Eu{sup 3+} ions shifts the CIE values towards warm white light region. • This single phase white light emitting phosphors have lower CCT values (<5000 K).

  20. Structural studies of type N superconductive compounds: R{sub 2-x}Ce{sub x}CuO{sub 4{+-}{delta}} (R = Gd, Eu, Sm, Nd, Pr); influences of chemical treatments on physical properties; Etudes structurales des composes supraconducteurs de type N: R{sub 2-x}Ce{sub x}CuO{sub 4{+-}{delta}} (R = Gd, Eu, Sm, Nd, Pr); influences des traitements chimiques sur les proprietes physiques

    Energy Technology Data Exchange (ETDEWEB)

    Vigoureux, P.

    1995-06-01

    Different chemical treatments of R{sub 2-x}Ce{sub x}CuO{sub 4{+-}{delta}} compounds monocrystals (gadolinium, europium, samarium, neodymium and praseodymium cuprates) modify their physical properties especially their superconductive properties. The presented chemical treatments are: the substitution of the trivalent rare earth element R by an other trivalent lanthanide, its substitution by tetravalent cerium, and heat treatment under low oxygen pressure. After these chemical treatments, structural modifications are observed by neutrons and X-rays diffraction, and allow to precise their actions: size effect of the rare earth element on the deformation of the CuO{sub 2} planes, links between deformation and superconductivity and magnetic properties. (A.B.). 394 refs/.

  1. ALnS2:RE (A=K, Rb; Ln=La, Gd, Lu, Y): New optical materials family

    International Nuclear Information System (INIS)

    Jarý, V.; Havlák, L.; Bárta, J.; Mihóková, E.; Buryi, M.; Nikl, M.

    2016-01-01

    In the presented review paper, new potentially interesting material family, RE-doped ternary sulfides ALnS 2 (RE=Ce, Pr, Sm, Eu, Tb, Tm; A=Rb, K; Ln=La, Gd, Lu, Y) is discussed. Their synthesis is described and the structural and optical properties, characterized by methods of X-ray diffraction, time-resolved luminescence spectroscopy and electron paramagnetic resonance, are summarized and reviewed especially with respect to the influence of their composition. All samples discussed were synthesized in the form of transparent crystalline hexagonal platelets by chemical reaction under the flow of hydrogen sulfide. Their luminescence characteristics, including absorption, radioluminescence, photoluminescence excitation and emission spectra and decay kinetics, were measured and evaluated in a broad temperature (8–800 K) and concentration (0.002–20% of dopants) range. The application potential of mentioned compounds in the field of white LED solid state lightings or X-ray phosphors is thoroughly discussed. - Highlights: • RE-doped ALnS 2 (A=K, Rb; Ln=La, Gd, Lu, Y) were synthesized. • Their optical characteristics are summarized. • Concentration and temperature dependences of luminescence features investigated. • EPR technique is employed to explain Eu 2+ incorporation into KLuS 2 host. • The application potential in white LED and X-ray phosphors is discussed.

  2. Formation of gapless Z 2 spin liquid phase manganites in the (Sm1- y Gd y )0.55Sr0.45MnO3 system in zero magnetic field: Topological phase transitions to states with low and high density of 2D-vortex pairs induced by the magnetic field

    Science.gov (United States)

    Bukhan'ko, F. N.; Bukhan'ko, A. F.

    2017-12-01

    The evolution of the ground state of the manganese spin ensemble in the (Sm1- y Gd y )0.55Sr0.45MnO3 in the case of isovalent substitution of rare-earth samarium ions with large radii with gadolinium ions with significantly smaller radii is studied. The measured temperature dependences of the ac magnetic susceptibility and the field dependences of the dc magnetizations are analyzed using the Heisenberg-Kitaev model describing the transition from the ordered spin state with classical isotropic AFM exchange to the frustrated spin state with quantum highly anisotropic FM exchange. A continuous transition from the 3D ferromagnetic state of manganese spins in the initial sample with y = 0 to zigzag AFM ordering of CE-type spins in ab planes for y = 0.5, coexisting in samples with y = 0.5, 0.6, and 0.7 at temperatures below T N ≅ 48.5 K with a disordered phase such as a quantum Griffiths phase is identified. As the gadolinium concentration further increases, the CE-type zigzag AFM structure is molten, which leads to the appearance of an unusual phase in Gd0.55Sr0.45MnO3 in the temperature range close to the absolute zero. This phase has characteristic features of a gapless Z 2 quantum spin liquid in zero external magnetic field. The step changes in the magnetization isotherms measured at 4.2 K in the field range of ±75 kOe are explained by quantum phase transitions of the Z 2 spin liquid to a phase with topological order in weak magnetic fields and a polarized phase in strong fields. The significant difference between critical fields and magnetization jumps in isotherms indicates the existence of hysteretic phenomena in quantum spin liquid magnetization-demagnetization processes caused by the difference between localization-delocalization of 2D vortex pairs induced by a magnetic field in a quantum spin liquid with disorder.

  3. Prism inside. Spectroscopic and magnetic properties of the lanthanide(III) chloride oxidotungstates(VI) Ln{sub 3}Cl{sub 3}[WO{sub 6}] (Ln = La - Nd, Sm - Tb)

    Energy Technology Data Exchange (ETDEWEB)

    Dorn, Katharina V.; Blaschkowski, Bjoern; Hartenbach, Ingo [Institute for Inorganic Chemistry, University of Stuttgart (Germany); Foerg, Katharina; Netzsch, Philip; Hoeppe, Henning A. [Institute for Physics, University of Augsburg (Germany)

    2017-11-17

    The lanthanide(III) chloride oxidotungstates(VI) with the formula Ln{sub 3}Cl{sub 3}[WO{sub 6}] for Ln = La - Nd, Sm - Tb were synthesized by solid-state reactions utilizing the respective lanthanide trichloride, lanthanide sesquioxide (where available), and tungsten trioxide together with lithium chloride as flux. The title compounds crystallize hexagonally in space group P6{sub 3}/m (no. 176, a = 941-909, c = 543-525 pm, Z = 2). The structures comprise crystallographically unique Ln{sup 3+} cations surrounded by six O{sup 2-} and four Cl{sup -} anions (C.N. = 10) forming distorted tetracapped trigonal prisms as well as rather uncommon trigonal prismatic [WO{sub 6}]{sup 6-} units, whose edges are coordinated by nine Ln{sup 3+} cations. Thus, a {sup 3}{sub ∞}{([WO_6]Ln"e_9_/_3)"3"+} framework (e = edge-sharing) is created, which contains tube-shaped channels along [001] lined with chloride anions. To elucidate the spectroscopic and magnetic properties of the obtained pure phase samples, single-crystal Raman (for Ln = La - Nd, Sm-Tb), diffuse reflectance (for Ln = La, Pr, Nd, Gd), and luminescence spectroscopy (for bulk Ln{sub 3}Cl{sub 3}[WO{sub 6}] (Ln = La, Eu, Gd, Tb) and Eu{sup 3+}- or Tb{sup 3+}-doped derivatives of La{sub 3}Cl{sub 3}[WO{sub 6}] and Gd{sub 3}Cl{sub 3}[WO{sub 6}], respectively) were performed and their temperature-dependent magnetic moments (for Ln = Pr, Nd, Gd) were determined. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. The nuclear deformations of 148Sm, 150Sm, 152Sm and 154Sm determined from neutron scattering measurements

    International Nuclear Information System (INIS)

    Shamu, R.; Haouat, G.; Lachkar, J.; Lagrange, C.; McEllistrem, M.; Patin, Y.; Sigaud, J.; Cocu, F.; Bernstein, E.; Ramirez, J.

    1975-01-01

    The neutron total cross section for 148 Sm and total cross section differences for ( 150 Sm, 148 Sm) and ( 152 Sm, 148 Sm) and ( 154 Sm, 148 Sm) were measured from 0.7 to 15MeV neutron energy and differential cross sections for 148 Sm, 150 Sm, 152 Sm and 154 Sm were measured at 7.0MeV neutron energy. The quadrupole deformation parameter of the nuclear potential, β2, was determined for each of the 148 Sm, 150 Sm, 152 Sm, 154 Sm nuclei from these measurements using nonspherical optical-potential coupled-channel calculations. The β2 values deduced for 152 Sm and 154 Sm are in good agreement with values determined from proton and α-particle scattering, but about 10% lower than β2 values of the nuclear charge distribution obtained from Coulomb excitation, electron scattering, and μ-meson scattering experiments [fr

  5. Simulated monazite crystalline wasteform La{sub 0.4}Nd{sub 0.1}Y{sub 0.1}Gd{sub 0.1}Sm{sub 0.1}Ce{sub 0.1}Ca{sub 0.1}(P{sub 0.9}Mo{sub 0.1}O{sub 4}): Synthesis, phase stability and chemical durability study

    Energy Technology Data Exchange (ETDEWEB)

    Pratheep Kumar, Sathasivam, E-mail: pratheepvit@gmail.com; Gopal, Buvaneswari

    2015-03-15

    Highlights: • Hexavalent molybdenum and selected lanthanides were immobilized into monazite structure at low temperature. • The wasteform has been characterized by powder XRD, FTIR, SEM-EDX and XPS analysis. • Immobilization of molybdenum was proved by energy dispersive X-ray analysis. • Chemical durability of the wasteform was studied by dynamic Soxhlet test. • Polymer–ceramic composite approach reduced the leaching of molybdenum from monazite lattice. - Abstract: In this work, incorporation of hexavalent molybdenum and selected trivalent lanthanides using divalent calcium as charge compensator into the monazite structure were studied. Rare earth substituted phosphomolybdates of the formula REE{sub 0.9}Ca{sub 0.1}P{sub 0.9}Mo{sub 0.1}O{sub 4} (REE = Ce, Nd, Sm, Gd) and the wasteform La{sub 0.4}Nd{sub 0.1}Y{sub 0.1}Gd{sub 0.1}Sm{sub 0.1}Ce{sub 0.1}Ca{sub 0.1}P{sub 0.9}Mo{sub 0.1}O{sub 4} were synthesized by simple solution route. The prepared compounds were characterized by powder X-ray diffraction, Fourier transformed infrared spectra, thermogravimetric analysis, energy dispersive X-ray analysis and scanning electron microscopic techniques. Chemical durability of the wasteform was studied by dynamic MCC-5 test for a period of one month. Normalized elemental mass loss and leach rate of molybdenum was found to be in the order of 10{sup 3} g/m{sup 2} and 10{sup 3}–10{sup 1} g/m{sup 2}/d respectively. Polymer-monazite composite wasteform was prepared to control the leaching of molybdenum. The composite approach reduced molybdenum leach rate order from 10{sup 1} to 10{sup −4} g/m{sup 2}/d.

  6. Half Life Measurements in {sup 155}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Malmskog, S.G.

    1966-08-15

    In the literature there exists a definite difference for the half life of the 86.5 keV level in Gd depending on whether {sup 155}Eu or {sup 155}Tb sources have been used. Using a good energy resolution electron-electron coincidence spectrometer and a {sup 155}Eu source, a half life of 6.48 {+-} 0.26 nsec was obtained for the 86.5 keV level. This is in agreement with the values previously measured with {sup 155}Tb sources. The half life of the 105.4 keV level was measured to be 1.12 {+-} 0.05 nsec.

  7. Half Life Measurements in 155Gd

    International Nuclear Information System (INIS)

    Malmskog, S.G.

    1966-08-01

    In the literature there exists a definite difference for the half life of the 86.5 keV level in Gd depending on whether 155 Eu or 155 Tb sources have been used. Using a good energy resolution electron-electron coincidence spectrometer and a 155 Eu source, a half life of 6.48 ± 0.26 nsec was obtained for the 86.5 keV level. This is in agreement with the values previously measured with 155 Tb sources. The half life of the 105.4 keV level was measured to be 1.12 ± 0.05 nsec

  8. Effect of rare-earth substitution at La-site on structural, electrical and thermoelectric properties of La0.7-xRExSr0.3MnO3 compounds (x = 0, 0.2, 0.3; RE = Eu, Gd, Y)

    Science.gov (United States)

    Choudhary, Y. R. S.; Mangavati, Suraj; Patil, Siddanagouda; Rao, Ashok; Nagaraja, B. S.; Thomas, Riya; Okram, G. S.; Kini, Savitha G.

    2018-04-01

    In the present communication, we present results on the effect of rare-earth (RE) substitution at La-site on the structural, electrical and thermoelectric properties of La0.7-xRExSr0.3MnO3 compounds. The lattice parameters are observed to decrease with RE-doping which is attributed to the fact that the substituted RE ions (RE = Eu, Gd and Y) are smaller than that of La ion. In high temperature semiconducting regime, small polaron hopping (SPH) model is valid, whereas, variable hopping model is valid in low temperature metallic region. The resistivity in the entire temperature range follows percolation model. All the samples exhibit sign reversal in thermopower, S. From temperature dependent S data, it is seen that SPH model is applicable in high temperature regime.

  9. Facile synthesis and luminescence properties of Y2O3:Ln(3+) (Ln(3+) = Eu(3+), Tb(3+), Dy(3+), Sm(3+), Er(3+), Ho(3+), Tm(3+), Yb(3+)/Er(3+), Yb(3+)/Tm(3+), Yb(3+)/Ho(3+)) microspheres.

    Science.gov (United States)

    Xu, Zhenhe; Zhao, Qian; Ren, Baoyi; You, Lixin; Sun, Yaguang

    2014-08-01

    Multicolor and monodisperse Y2O3:Ln(3+) (Ln(3+) = Eu(3+), Tb(3+), Dy(3+), Sm(3+), Er(3+), Ho(3+), Tm(3+), Yb(3+)/Er(3+), Yb(3+)/Ho(3+)) microspheres were prepared through a facile urea-assisted homogeneous precipitation method followed by a subsequent calcination process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectrum (EDS), Fourier transformed infrared (FT-IR), thermogravimetric analysis (TGA), photoluminescence (PL) and cathodoluminescence (CL) spectra were employed to characterize the samples. The XRD results reveal that the as-prepared spheres can be well indexed to cubic Y2O3 phase with high purity. The SEM and TEM images show the obtained Y2O3:Ln(3+) samples consist of regular nanospheres with the mean diameter of 350 nm. And the possible formation mechanism is also proposed. Upon ultraviolet and low-voltage electron beams excitation, Y2O3:Ln(3+) (Ln(3+) = Eu(3+), Tb(3+), Dy(3+), Sm(3+), Er(3+), Ho(3+), Tm(3+)) samples exhibit respective bright red (Eu(3+), (5)D0 --> (7)F2), green (Tb(3+), (5)D4 --> (7)F5), blue (Dy(3+), (4)F9/2 --> (6)H13/2), yellow (Sm(3+), (4)G5/2 --> (6)H7/2), green (Er(3+), (4)S3/2 --> (4)I15/2), green (Ho(3+), (5)S2 --> (5)I8), blue (Tm(3+), (1)D2 --> (3)F4) down-conversion (DC) emissions. Under 980 nm NIR irradiation, Y2O3:Ln(3+) (Ln(3+) = Yb(3+)/Er(3+), Yb(3+)/Tm(3+) and Yb(3+)/Ho(3+)) exhibit characteristic up-conversion (UC) emissions of green (Er(3+), (2)H11/2, (4)S3/2, (2)H11/2 --> (4)I5/2), blue (Tm(3+), (1)G4 --> (3)H6) and green (Ho(3+), (5)F4, (5)S2 --> (5)I8), respectively. These merits of multicolor emissions in the visible region endow this kind of material with potential applications in the field of light display systems, lasers, and optoelectronic devices.

  10. Determinación del coeficiente piroeléctrico del sistema ferroeléctrico cerámico de Pb0.88Ln0.08Ti0.98Mn0.02O3 (Ln=La, Sm, Eu y su aplicación en detectores de infrarrojo

    Directory of Open Access Journals (Sweden)

    Suaste-Gómez, E.

    2004-12-01

    Full Text Available In this work the dielectric and pyroelectric characteristics of the ferroelectric ceramic system of Pb0.88(Ln0.08Ti0.98Mn0.02O3 (Ln = La, Sm, Eu are studied in order to determine its usefulness as infrared dectectors. Dielectric constant and pyroelectric coefficient of the ceramics were determined. This material with perovskite structure presented a phase transition from tetragonal to cubic on the heating process, besides of presenting high values of dielectric constant. Values of figure of merit for infrared detection Rv=pi/εr were calculated. The results were compared with other materials used as infrared detectors.En este trabajo se estudian las características dieléctricas y piroeléctricas del sistema ferroléctrico cerámico de Pb0.88(Ln0.08Ti0.98 Mn0.02O3 (Ln = La, Sm, Eu para determinar su utilidad como detectores de infrarrojo. Se determinó la constante dieléctrica y el coeficiente piroeléctrico de las cerámicas. Este material con estructura de perovskita presentó una transición de fase tetragonal a cúbica en el proceso de calentamiento, además de presentar altos valores de la constante dieléctrica. Se obtuvieron valores de la figura de mérito para detección infrarroja Rv=pi/εr Los resultados se compararon con otros materiales usados como detectores de infrarrojo.

  11. Coherent potential approximation treatment of the Sm valence transition in SmS induced by alloying

    International Nuclear Information System (INIS)

    Spronken, G.

    1982-01-01

    The Sm valence transition, similar to the pressure-induced transition in pure SmS, has been observed in a large number of cases by substituting a trivalent rare earth, B, for Sm, thereby forming isostructural alloys with a lattice constant smaller than that of semiconducting SmS. Such substitutions are expected to exert a 'chemical' pressure which simulates the external pressure. However, divalent substitutions (Yb, Eu and Ca), although having a favourable 'size' factor, do not induce any valence transition. Accordingly, band structure effects, essentially due to the relative position of the conduction bands of SmS and BS, should also be taken into consideration. In order to clarify the role which the lattice constant and the electronic structure play in the valence transition, these alloys have been studied using the coherent potential approximation (CPA) including both the crystal field effect and the Coulomb interaction between localised and itinerant states as driving mechanisms. For Sm, the 'homogeneous' picture is considered, each Sm site having the average valence; then the Smsub(1-x)Bsub(x)S system is reduced to a binary alloy. Charge transfer between the f states of Sm and the alloy conduction band (i.e. Sm valence change) is determined self-consistently. The calculations are consistent with the experimental behaviour and allow us to understand qualitatively the variation of the critical concentration xsub(c) for the transition as a function of the difference Δa between the lattice parameters of SmS and BS. (author)

  12. Strongly coupled band in {sup 140}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil)] (and others)

    2005-07-01

    Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, K{pi} = 8{sup -} isomers, with lifetimes ranging from ns to ms, are known in {sup 128}Xe, {sup 130}Ba, {sup 132}Ce, {sup 134}Nd, {sup 136}Sm, and {sup 138}Gd[. In {sup 140}Gd, we have observed for the first time a band also based on an I{pi} = 8{sup -} state. This could be the first case of a K{pi} = 8{sup -} state observed in an N=76 even-even isotope. The systematics of the K{pi} = 8{sup -} isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The {sup 140}Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in {sup 140}Gd.

  13. EU Udbudsretten

    DEFF Research Database (Denmark)

    Poulsen, Sune Troels; Jakobsen, Peter Stig; Kalsmose-Hjelmborg, Simon Evers

    I bogen, som er en 2. udgave, analyseres EU udbudsdirektiv for offentlige myndigheder og EU's forsyningsvirksomhedsdirektiv. I analyserne inddrages EU-domstolens domme, afgørelser fra Kalgenævnet for Udbud, domme fra danske domstole samt litteratur på dansk og engelsk.......I bogen, som er en 2. udgave, analyseres EU udbudsdirektiv for offentlige myndigheder og EU's forsyningsvirksomhedsdirektiv. I analyserne inddrages EU-domstolens domme, afgørelser fra Kalgenævnet for Udbud, domme fra danske domstole samt litteratur på dansk og engelsk....

  14. 155Gd Moessbauer spectroscopic investigation of 3d-4f and 4f-4f' dinuclear complexes containing Gd (III)

    International Nuclear Information System (INIS)

    Ayabe, T.; Takahashi, M.; Takeda, M.; Costes, J.P.

    2006-01-01

    155 Gd Moessbauer spectra for dinuclear complexes of Gd 3+ and lanthanide (III) ion having a Schiff base ligand (L) derived from tren and 3-ethoxysalicylaldehyde were measured at 12 K. Moessbauer spectra of these complexes showed quadrupole split spectra. Two kinds of isomer shift values are observed; i.e, δ=0.57 - 0.60 mm s -1 for LGdLn' (Ln' = Ce, Nd, Eu, Gd) and δ=0.64-0.66 mm s -1 for LLnGd (Ln=Dy, Er, Yb). The former values are very close to those of nitrogen-containing Gd (III) complexes (δ=0.59-0.62 mm s -1 ) such as edta and cyano-bridged complexes. The latter values are on the other hand, in the range of oxygen-coordinating Gd (III) complexes (δ=0.64-0.65 mm s -1 ) such as polyethylene glycol Gd (III) complexes. 155 Gd Moessbauer spectra for LLnLn' complexes indicate that the smaller lanthanide ion Ln is in the N 4 O 3 site and the larger ion Ln' in the O 10 site. (author)

  15. Nanoscale Gd.sub.2./sub.BaCuO.sub.5./sub. particles in (Sm.sub.0.33./sub.Eu.sub.0.33./sub.Gd.sub.0.33./sub.)Ba.sub.2./sub.Cu.sub.3./sub.O.sub.y./sub. and magnetic levitation at 90.2 K

    Czech Academy of Sciences Publication Activity Database

    Muralidhar, M.; Sakai, N.; Jirsa, Miloš; Murakami, M.; Koshizuka, N.

    2005-01-01

    Roč. 18, - (2005), L9-L12 ISSN 0953-2048 Institutional research plan: CEZ:AV0Z10100520 Keywords : LRE-123 * vortex pinning * secondary phase particles * bulk melt-textured superconductor s * magnetic levitation * liquid oxygen Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.896, year: 2005

  16. Suppression of the low-temperature phase-separated state under pressure in (Eu{sub 1-x}Gd{sub x}){sub 0.6}Sr{sub 0.4}MnO{sub 3} (x=0,0.1)

    Energy Technology Data Exchange (ETDEWEB)

    Inomata, Tasuku [Department of Materials Science and Engineering, Iwate University, Morioka 020-8551 (Japan); Matsukawa, Michiaki, E-mail: matsukawa@iwate-u.ac.jp [Department of Materials Science and Engineering, Iwate University, Morioka 020-8551 (Japan); Kimura, Daichi; Yamato, Yoshiaki; Kobayashi, Satoru [Department of Materials Science and Engineering, Iwate University, Morioka 020-8551 (Japan); Suryanarayanan, Ramanathan [Laboratoire de Physico-Chimie de L' Etat Solide, CNRS, UMR8648 Universite Paris-Sud, 91405 Orsay (France); Nimori, Sigeki [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Koyama, Keiichi [Graduate School of Science and Engineering, Kagoshima University, Kagoshima 890-0065 (Japan); Takahashi, Kohki; Watanabe, Kazuo; Kobayashi, Norio [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2012-11-15

    We have demonstrated the effect of pressure on the steplike metamagnetic transition and its associated magnetostriction in (Eu{sub 1-x}Gd{sub x}){sub 0.6}Sr{sub 0.4}MnO{sub 3} (x=0 and 0.1). The critical field initiating the field induced ferromagnetic transition in both samples is lowered by the applied pressure. The further application of external pressure up to 1.2 GPa on the x=0 parent sample causes a spontaneous ferromagnetic transition with a second-order like character, leading to collapses of the steplike transition and its concomitant lattice striction. These findings indicate a crucial role of the low-temperature phase separated state characterized by a suppressed magnetization upon decreasing temperature. - Highlights: Black-Right-Pointing-Pointer Phase separated manganite exhibits the low-temperature step-like metamagnetic transition. Black-Right-Pointing-Pointer The low-temperature phase separated state is characterized by a suppressed magnetization. Black-Right-Pointing-Pointer The applied pressure collapses the phase separated state, giving a ferromagnetic transition. Black-Right-Pointing-Pointer The step-like magnetic transition accompanies its associated magnetostriction jump.

  17. Systematic investigation of structural, transport, magnetic and thermodynamic properties of hexagonal R2Pt6Al15 (R = Y, La-Nd, Sm-Lu) series

    Science.gov (United States)

    Manni, Soham; Lin, Q.; Bud'Ko, S. L.; Canfield, P. C.

    We have synthesized single crystals of new hexagonal intermetallic series of compounds R2Pt6Al15 with R = Y, La-Nd, Sm-Lu. Structural analysis have confirmed hexagonal P63 / mmc crystal structure with ordered R-site. Magnetic, transport and heat capacity measurements show that most of the members of the series order antiferromagnetically at low temperature with highest TN = 7.5 K for Gd2Pt6Al15 and moments are along c-axis except Dy2Pt6Al15 and Ho2Pt6Al15. Ce2Pt6Al15 does not order, but shows insulating behavior with a strong divergence in heat capacity divided by temperature (C / T). Mixed valence state of Eu2+/Eu3+ state has been observed in Eu2Pt6Al15 with antiferromagnetic ordering below 3 K. Magnetic entropy and crystal electric field are analyzed for all the members from the magnetic contribution of heat capacity. This series of compounds serves a unique example of a rare earth series with only one rare earth (R) site having hexagonal point-symmetry. This research is funded by the Gordon and Betty Moore Foundation's EPiQS Initiative through Grant GBMF4411 and by U.S. Department of Energy under Contract No. DE-AC02-07CH11358.

  18. Crystal growth, structure and magnetic properties of Sm3Ni5Al19: A ...

    Indian Academy of Sciences (India)

    Abstract. Sm3Ni5Al19 was obtained as large rod shaped single crystals from reactive aluminium flux. Single crystal X-ray diffraction suggests that Sm3Ni5Al19 crystallizes in the Gd3Ni5Al19 structure type, orthorhombic space group Cmcm and lattice constants a= 4.0974(1) Å, b = 16.0172(6) Å and c = 27.0774(10).

  19. Uplatnění ekohydrologických principů při řízení zemědělsky využívaného povodí podle Rámcové vodní směrnice EU (2000/60/EU)

    Czech Academy of Sciences Publication Activity Database

    Hejzlar, Josef; Kopáček, Jiří; Dobiášová, B.; Žaloudík, Jiří

    2004-01-01

    Roč. 21, č. 3 (2004), s. 261-264 ISSN 1212-0731. [Agroregion 2004. České Budějovice, 06.09.2004-07.09.2004] R&D Projects: GA AV ČR(CZ) IBS6017004; GA AV ČR(CZ) IAA3017301 Grant - others:EU(XE) EUROHARP EVK1-CT-2001-00096 Keywords : restoration of aquatic ecosystems * nitrogen * phosphorus Subject RIV: DJ - Water Pollution ; Quality

  20. Magnetocaloric effect in high Gd content Gd-Fe-Al based amorphous/nanocrystalline systems with enhanced Curie temperature and refrigeration capacity

    Directory of Open Access Journals (Sweden)

    Linlin Zhang

    2016-03-01

    Full Text Available The Gd-Fe-Al amorphous/nanocrystalline composites were successfully designed and obtained with both high Curie temperature (Tc and large magnetic entropy change (ΔSM. The Tc can be tuned from 172 to 280 K and refrigeration capacity (RC has a value between 690 and 867 J/kg under a field change of 0–5 T by changing the Gd contents and the formation of Gd nanocrystallites. And, ΔSM in Gd-Fe-Al amorphous/nanocrystalline composites reached a value of 7.2 J kg−1 K−1 under a field change of 0–5 T. The high RC in Gd-Fe-Al system were ascribed to the widening full width at half maximum (δFWHM up to 240 K of the magnetic entropy change (ΔSMmax peak because of the combination contribution of amorphous matrix and the precipitated Gd-riched nanocrystalline. Our research would shed light on how to design attractive candidates for magnetic refrigeration materials with high performance at near room temperature.

  1. Surface effects on Sm valence in amorphous Sm alloys

    International Nuclear Information System (INIS)

    Krill, G.; Durand, J.; Berrada, A.; Hassanain, N.; Ravet, M.F.

    1980-01-01

    The results are presented of XPS and X-ray absorption measurements performed on amorphous Sm Au and La Sm Au compounds. The XPS Sm 3dsub(5/2) core level spectra in these compounds reveal that at the surface (5 to 7 A) the samarium ions present both the Sm 2+ (4f 6 ) and Sm 3+ (4f 5 ) configurations. When the concentration in samarium decreases it is shown that the Sm 2+ configuration is strongly enhanced at the surface whereas the X-ray absorption measurements indicate on the contrary that in the bulk only the Sm 3+ configuration is present. Comparison is made with similar findings in pure crystalline Sm and various crystalline rare earth compounds. (author)

  2. Synthesis, crystal structure, and magnetic properties of novel 2D kagome materials RE{sub 3}Sb{sub 3}Mg{sub 2}O{sub 14} (RE = La, Pr, Sm, Eu, Tb, Ho): Comparison to RE{sub 3}Sb{sub 3}Zn{sub 2}O{sub 14} family

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, M.B.; Baroudi, K.M.; Krizan, J.W.; Mukadam, O.A.; Cava, R.J. [Department of Chemistry, Princeton University, Princeton, NJ (United States)

    2016-10-15

    The crystal structures and magnetic properties of RE{sub 3}Sb{sub 3}Mg{sub 2}O{sub 14} (RE = La, Pr, Sm, Eu, Tb, Ho) with a perfect kagome lattice are presented and compared to RE{sub 3}Sb{sub 3}Zn{sub 2}O{sub 14}. Rietveld structure refinements were performed using X-ray diffraction data, indicating that the layered compounds are fully structurally ordered. The compounds crystallize in a rhombohedral supercell of the cubic pyrochlore structure, in the space group R-3m. Magnetic susceptibility measurements show no signs of magnetic ordering above 2 K. The RE{sub 3}Sb{sub 3}Mg{sub 2}O{sub 14} family is similar to that of RE{sub 3}Sb{sub 3}Zn{sub 2}O{sub 14}; however, the series reported here features a fully ordered distribution of cations in both the nonmagnetic antimony and magnetic rare earth kagome lattices. Unlike the offsite disorder that Zn{sup 2+} experiences in RE{sub 3}Sb{sub 3}Zn{sub 2}O{sub 14}, the magnesium sites in RE{sub 3}Sb{sub 3}Mg{sub 2}O{sub 14} are completely ordered. Here we compare the magnetic properties in both series of kagome compounds to determine how significant Zn{sup 2+}'s positional ordering is within this structure type. The compounds reported here appear to be relatively defect-free and are therefore model systems for investigating magnetic frustration on an ideal 2D rare earth kagome lattice. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Guided ion beam and theoretical studies of the bond energy of SmS.

    Science.gov (United States)

    Armentrout, P B; Demireva, Maria; Peterson, Kirk A

    2017-12-07

    Previous work has shown that atomic samarium cations react with carbonyl sulfide to form SmS + + CO in an exothermic and barrierless process. To characterize this reaction further, the bond energy of SmS + is determined in the present study using guided ion beam tandem mass spectrometry. Reactions of SmS + with Xe, CO, and O 2 are examined. Results for collision-induced dissociation processes with all three molecules along with the endothermicity of the SmS + + CO → Sm + + COS exchange reaction are combined to yield D 0 (Sm + -S) = 3.37 ± 0.20 eV. The CO and O 2 reactions also yield a SmSO + product, with measured endothermicities that indicate D 0 (SSm + -O) = 3.73 ± 0.16 eV and D 0 (OSm + -S) = 1.38 ± 0.27 eV. The SmS + bond energy is compared with theoretical values characterized at several levels of theory, including CCSD(T) complete basis set extrapolations using all-electron basis sets. Multireference configuration interaction calculations with explicit spin-orbit calculations along with composite thermochemistry using the Feller-Peterson-Dixon method and all-electron basis sets were also explored for SmS + , and for comparison, SmO, SmO + , and EuO.

  4. EU Enlargement

    DEFF Research Database (Denmark)

    Pedersen, Peder J.; Pytlikova, Mariola

    We look at migration flows from 8 Central and Eastern European Countries (CEECs) to 5 Nordic countries over the years 1985 - 2005 and we can exploit a natural experiment that arose from the fact that while Sweden opened its labour market from the day one of the 2004 EU enlargement, the other Nordic...... countries chose a transition period in relation to the "new" EU members. We employ a differences-in-differences estimator in our analysis. The results show that the estimated effect of the opening of Swedish labour market in 2004 on migration is insignificantly different from zero. Further, we...

  5. Sodium acetate assisted hydrothermal growth of dumbbell-like β -NaGdF4 nanobundles: Morphology control and products transformation

    Science.gov (United States)

    Wu, Kelu; Wang, Yi-Yan; Xia, Tian-Long

    2017-08-01

    Hierarchical β -NaGdF4 nanobundles are synthesized through a facile hydrothermal method with the use of sodium acetate (NaAc). A NaGdF4-GdF3-NaGdF4 products transformation with the increase of fluoride source (NaF) is observed. Results show that NaAc is the key factor in the synthesis of β -NaGdF4 at a low NaF/Gd3+ ratio and NaAc also plays a significant role in the formation of the hierarchical morphology. Meanwhile, the size of nanobundles increases with the increased ratio of NaF/NaAc. With altering the ratio of reactants, dumbbell-like, urchin-like or rod-like β -NaGdF4 nanobundles are obtained. The photoluminescent properties of β -NaGdF4: 2%Eu3+ are also measured.

  6. Okpara, EU

    African Journals Online (AJOL)

    Okpara, EU. Vol 31, No 1 (2014) - Articles Pregnancy Outcome in Cervical Incompetence: Comparison of Outcome Before and After Intervention Abstract. ISSN: 0189-5117. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms ...

  7. Study of Gd lattices

    International Nuclear Information System (INIS)

    Vidovsky, I.; Kereszturi, A.

    1991-11-01

    The results of experiments and calculations on Gd lattices are presented, and a comparison of experimental and calculational data is given. This latter can be divided into four groups. The first belongs to the comparison of criticality parameters, the second group is related with the comparison of 2D distributions, the third one relates the comparison of intra-macrocell distributions, whereas the fourth group is devoted for the comparison of spectral parameters. For comparison, the computer code RFIT based on strict statistical criteria has been used. The calculated and measured results agree, in most cases, sufficiently. (R.P.) 11 refs.; 13 figs.; 9 tabs

  8. SM18 Visits and Access

    CERN Multimedia

    2012-01-01

      VISITS The rules and conditions to be followed for visits in the SM18 Hall are laid out in the EDMS 1205328 document. No visit is allowed without prior reservation.   ACCESS Special access right is needed ONLY from 7 p.m. to 7 a.m. and during week-ends. From 1 December, the current SM18 access database will be closed and a new one “SM18-OWH outside normal hours” started from scratch. Requests, via EDH SM18-OWH, will have to be duly justified.   For further information, please contact Evelyne Delucinge.

  9. 111Cd PAC Study of Gd-Ni Intermetallic Compounds

    International Nuclear Information System (INIS)

    Presa, P. de la; Forker, M.

    2004-01-01

    This paper presents a perturbed angular correlation study of the magnetic and electric hyperfine interactions of 111 Cd on Gd sites of the Gd-Ni intermetallic compounds GdNi, GdNi 2 , GdNi 3 , Gd 2 Ni 7 , GdNi 5 and Gd 2 Ni 17 .

  10. A study of the Eu3+ charge-transfer state in lanthanide-borate glasses

    NARCIS (Netherlands)

    Verwey, J.W.M.; Dirksen, G.J.; Blasse, G.

    1988-01-01

    The luminescence properties of the Eu[3+] ion in lanthanide- borate glasses were investigated and compared with those of Eu[3+] in Crystalline GdB3O6. In these materials the emission observed is from the [5]DO to the [7]FJ levels. The rate of nonradiative relaxation from the charge-transfer state

  11. Standard Missile-6 (SM-6)

    Science.gov (United States)

    2016-12-01

    assets . SM-6 December 2015 SAR March 17, 2016 12:06:05 UNCLASSIFIED 6 Executive Summary The SM-6 program was designated as an ACAT 1C program with the...FYDP for higher Navy priorities. (Estimating) -22.6 -30.1 Adjustment for current and prior escalation. (Estimating) +6.1 +7.7 Adjustment for current and

  12. 24/7 SM slavery.

    Science.gov (United States)

    Dancer, Peter L; Kleinplatz, Peggy J; Moser, Charles

    2006-01-01

    This study describes the nature of 24/7 SM slavery as practiced within the SM (sadomasochistic) community. These SM participants, who attempt to live full-time in owner-slave roles, represent a small proportion of those with SM interests. SM slaves have not been studied systematically to determine if and how they differ from other SM practitioners. An online questionnaire was used to obtain responses from individuals who self-identified as slaves. A total of 146 respondents participated, 53% female and 47% male, ranging in age from 18 to 72. We explored the depth of their relationships, how well they approximated "slavery," and how their relationships were structured to maintain distinct roles. Data showed that in long-term SM slave relationships, a power differential exists which extends beyond time-limited SM or sexual interactions. Owners and slaves often use common, daily life experiences or situations, such as the completion of household chores, money management, and morning or evening routines, to distinguish and maintain their respective roles. In addition, contrary to the perception of total submission, results revealed that slaves exercise free will when it is in their best interests to do so. These relationships were long-lasting and satisfying to the respondents.

  13. Extraction of 152Gd from HFIR control plates

    International Nuclear Information System (INIS)

    Kohring, M.W.

    1986-01-01

    The primary method of 153 Gd production at the Oak Ridge National Lab. (ORNL) research reactors since 1980 has been the irradiation of a natural europium oxide powder (Eu 2 O 3 ) followed by the chemical extraction of the gadolinium fraction. The specific activity of the resulting source is 45 to 50 Ci/g with a radiochemical purity of > 99.99%. A potential alternative method involves the extraction of gadolinium from the europium-bearing region of highly radioactive, spent control plates used in the High Flux Isotope Reactor (HFIR), followed by neutron irradiation. This alternative to the traditional process is attractive in that chemical separation of the europium and gadolinium occurs before the 153 Gd production irradiation, thus reducing process and decay losses and, most significantly, the gadolinium is highly enriched in the parent isotope, 152 Gd. Investigation into the usefulness of the gadolinium isotopes contained in spent HFIR control plates began in the late 1960s. However, separation of the gadolinium from the europium to the purity levels required for a marketable specific activity could not be attained. Due to the recent increase in 153 Gd demand and separation process improvements, research into this valuable source of parent material was resurrected

  14. Og vinderen er ... EU

    DEFF Research Database (Denmark)

    Wæhrens, Anne

    2012-01-01

    EU modtager i dag Nobels Fredspris. Prisen kan styrke den fortælling, som EU har forsøgt at skabe om sig selv: at Europa, takket være EU, rejste sig efter Anden Verdenskrig og Holocaust......EU modtager i dag Nobels Fredspris. Prisen kan styrke den fortælling, som EU har forsøgt at skabe om sig selv: at Europa, takket være EU, rejste sig efter Anden Verdenskrig og Holocaust...

  15. InterProScan Result: EU935628 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available EU935628 EU935628_1_ORF1 0890A7FF4EDDBB08 SMART SM00093 SERPIN 4.000003008698826E-9... T IPR000215 Protease inhibitor I4, serpin Molecular Function: serine-type endopeptidase inhibitor activity (GO:0004867) ...

  16. Pinning Properties of PLD (NdxSmxGd1−2x)Ba2Cu3O7−δ Thin films

    DEFF Research Database (Denmark)

    Li, Xiaofen; Grivel, Jean-Claude; Yue, Zhao

    2012-01-01

    that the accommodation field at low temperature is increased due to the substitution. However, the decay of the self field critical current density and less effective pinning at higher temperature make the high level substituted films less attractive compared with the low level substituted film from the application......The self field critical current density, flux relaxation rate and accommodation field is studied in ternary rare earth (RE) barium cuprate thin films made by PLD on STO, with RE=Nd, Sm and Gd. By systematically changing the substitution level of Nd and Sm in GdBCO films, we found...

  17. Magnetic properties of Gd intermetallics

    Science.gov (United States)

    Petit, L.; Szotek, Z.; Jackson, J.; Lüders, M.; Paudyal, D.; Mudryk, Y.; Pecharsky, V.; Gschneidner, K. A.; Staunton, J. B.

    2018-02-01

    Using first-principles calculations, based on disordered local moment theory, combined with the self-interaction corrected local spin density approximation, we study magnetic interactions in GdX intermetallics for X = Cu, Zn, Ga, Cd, and Mg. Our predicted magnetic orders and ordering temperatures both at zero and other pressures agree well with experiments including the large increase in the Curie temperature of GdCd under pressure that is shown by our own experimental measurements. From our results it emerges that the Ruderman-Kittel-Kasuya-Yosida interaction on its own can not explain the observed behaviour under pressure, and that the magnetic ordering mechanism is strongly influenced by the occupations of both Gd and anion d-bands.

  18. Transportforskning i EU

    DEFF Research Database (Denmark)

    Leleur, Steen

    1996-01-01

    Artiklen giver en gennemgang af aktuelle EU transportforskningsemner samt nogle synspunkter og erfaringer baseret på deltagelse i EU forskningsprojekter.......Artiklen giver en gennemgang af aktuelle EU transportforskningsemner samt nogle synspunkter og erfaringer baseret på deltagelse i EU forskningsprojekter....

  19. Search for tetrahedral in 156Gd nucleus by γ spectroscopy

    International Nuclear Information System (INIS)

    Doan, Q.T.

    2009-11-01

    Theoretical calculations using realistic mean-field method suggest the existence of nuclear shapes with tetrahedral and/or octahedral symmetries in some rare earth nuclei around 156 Gd and 160 Yb. In nuclei with exact tetrahedral symmetry, the E2 intra-band transitions are predicted to vanish completely or to be very weak. This work is devoted to an experimental research of the tetrahedral symmetry in the nucleus 156 Gd. An experiment has been carried out with the JUROGAM γ-rays detector at Jyvaskyla (Finland) by using the fusion-evaporation reaction 154 Sm(α,2n) 156 Gd. In analysis, the branching ratios of two parity negative bands were determined, the angular distribution has been analyzed to determine the nature of one inter-band transition between these two bands. The transitions strength ratios determined are of the same order of magnitude as previous experiments, and some upper limits have been established for the lowest spin. The missing of the E2 transitions below the I π = 9 - states in the odd spin parity negative band were confirmed. The results of this work reinforced the hypothesis of the tetrahedral symmetry in the nucleus 156 Gd. γ-ray spectroscopy is the major tool used for this work. Detection principles and γ-ray simulations are detailed in the document. The simulation, based on realistic events, has been realised to compare the response function of two multi-detectors EUROBALL and AGATA. The results show that under certain conditions the first phase of AGATA (demonstrator) is also a tool to search for rare events. (author)

  20. Investigation of 155Gd, 157Gd and 159Gd nuclear deformation

    International Nuclear Information System (INIS)

    Araujo, J.M.R. de.

    1979-01-01

    Theoretical calculations of Transition Probabilities, Quadrupole Moments and Differential Inelastic Electron Cross-Sections for 155 Gd, 157 Gd and 159 Gd, for the first and second energy levels of the fundamental rotational band are presented. Electrons are described as distorted waves and the even-odd nuclei by means of the rotational model, with one particle strongly coupled to the even-even core. The intrinsic charge distribution of the core is deacribed by the Deformed Fermi Distribution and the extra particle by a single particle in a deformed harmonic potential produced by the core (Nilsson model). The inelastic electron cross-sections results show the possibility of a precise determination of deformation of the even-odd nuclei if measurements are carried. (author) [pt

  1. The preparation of 153Sm-glucoheptonate

    International Nuclear Information System (INIS)

    Pu Manfei; Luo Shunzhong; Liu Yebing; Liu Guoping; Wang Wenjin; Chen Qiping; Liu Zhonglin; Fu Yibei

    2003-01-01

    Influences of labeling conditions on the formation of glucoheptonate (GH) labelled with 153 Sm and in vitro stability of 153 Sm-GH are investigated. The effective labelling method of GH labelled with 153 Sm is established. The results show that the labelling yield of 153 Sm-GH is more than 98% using an open nitrogen-pouring labelling system heated in boiling water bath with reactive time not less than 30 min, concentration of GH more than 2.4 x 10 - '2 mol/L. The specific activity of 153 Sm-GH is up to 14 GBq/g (GH) using 153 SmCl 3 with the high specific activity of 153 Sm (∼4.5 TBq/g(Sm)). 153 Sm-GH can remain well with its radioactive chemical purity more than 96% within 40 hours at room temperature

  2. Phase equilibria in Sm-Ga-S ternary system according to SmGa2-GaS, SmGa2-SmS, Sm3S4-Ga2S3, SmS-GaS, Sm-GaS cross sections

    International Nuclear Information System (INIS)

    Alieva, O.A.; Aliev, O.M.; Ehjnullaev, A.V.

    1993-01-01

    Phase equilibria in ternary system Sm-Ga-S over cross sections SmGa 2 -GaS, SmGa 2 -SmS, SmS-GaS, Sm 3 S 4 -Ga 2 S 3 , Sm-GaS have been studied for the first time using the methods of physicochemical analysis, their T-x projections were plotted. The cross sections SmGa 2 -GaS, SmGa 2 -SmS, Sm 3 S 4 -Ga 2 S 3 and SmS-GaS are quasibinary, while Sm-GaS is nonquasibinary one. Formation of two ternary compounds of the composition Sm 4 GaS 5 and Sm 5 Ga 2 S 5 was ascertained by peritectic reactions

  3. Superconductivity and magnetism in Ir-doped GdFeAsO

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Y.J.; Chen, Y.L. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [School of Materials Science and Engineering, University of New South Wales, Sydney 2052 NSW (Australia); Yang, Y.; Jiang, J.; Wang, Y.Z.; Zhang, Y. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Y., E-mail: yzhao@swjtu.edu.c [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052 NSW (Australia)

    2010-11-01

    The 5d-transition metal, Ir has successfully been doped at Fe site and induced superconductivity in GdFeAsO at T{sub c} = 18.9 K and {approx}20 atom%. The Ir-doping shortened the c-axis length and stretched the a-axis one, which led to enhance the coupling between the FeAs- and SmO-layer, and to weaken the bonding between Fe and As atom. Paramagnetism was observed in all of the samples, which was resulted from the magnetic Gd ion as in the F-doped GdFeAsO. An upper critical field of GdFe{sub 0.8}Ir{sub 0.2}AsO was extrapolated to around 24 T, much smaller than that of F-doped GdFeAsO owing to a relatively low T{sub c} and small value of dH{sub c2}/dT.

  4. Type setted SM tahir2

    African Journals Online (AJOL)

    Dr Ahmed

    The tap root with branches and root hairs were buried to a depth of about 99.7cm. FULL LENGTH RESEARCH ARTICLE. STUDIES ON THE GERMINATION AND SEEDLING. CHARACTERISTICS OF THE SAVANNA. PALM TREES. *TAHIR, S.M.1 MU'AZU, S.2, KHAN, A.U2 & IORTSUUN, D.N.2. Department of Biological ...

  5. Radiation damage in SmS, SmSsub(1-x)Psub(x) and SmB6

    International Nuclear Information System (INIS)

    Morillo, J.; Bordier, G.; de Novion, C.H.; Senateur, J.P.; Jun, J.

    1984-08-01

    Large conductivity increases under 21 K electron or neutron irradiations are observed in SmS and SmSsub(1-x)Psub(x). It is shown that they are related to Sm defects. A possible mechanism is 4f electron delocalization around radiation defects. In SmB 6 , the low temperature resistivity increase desappears under 21 K irradiation. The thermal stability of the defects is also investigated up to room temperature

  6. Creating EU law judges

    DEFF Research Database (Denmark)

    Mayoral Diaz-Asensio, Juan Antonio; Jaremba, Urszula; Nowak, Tobias

    2014-01-01

    The judicial protection system in the European Union (EU) is premised on the fact that national judges are supposed to act as decentralized EU judges. This role is exercised through tools enshrined in, inter alia, primacy, direct and indirect effect of EU law, and the preliminary ruling procedure....... However, a number of studies show that national judges experience difficulties in exercising EU competences due to their lack of knowledge in the field of EU law. In this contribution we study the differences in the level of self-evaluation of EU law knowledge among judges, which consequently influence...... the way judges approach EU law. For that purpose we question the relevance of several institutional and socio-legal factors, such as organization of the judiciary, generation, the system of legal education and judicial training and practical experience with EU law. Our analysis is based on data collected...

  7. Discrimination of SM-Identified Individuals

    OpenAIRE

    Wright, Susan

    2006-01-01

    The misconception that sadomasochism (SM) is violence or abusive behavior has resulted in significant persecution against SM-identified individuals in the form of discrimination, harassment and physical attacks. Historically, women who practiced SM were targeted within the feminist movement due to official opposition against sadomasochistic practices led by the National Organization for Women (NOW). Current statistics of incidents of discrimination, harassment and physical attacks against SM-...

  8. Excited states in 146Sm and 147Sm

    International Nuclear Information System (INIS)

    Kownacki, J.; Sujkowski, Z.; Hammaren, E.; Liukkonen, E.; Piiparinen, M.; Lindblad, Th.; Ryde, H.

    1979-10-01

    The sup(144,146)Nd(α,xn) and sup(146,148)Nd( 3 He,xn) reactions with Esub(α) = 20 - 43 MeV and E 3 sub(He) = 19 - 27 MeV are used to investigate excited states in the isotopes 146 Sm and 147 Sm. The experiments involve measurements of singles γ-ray spectra and conversion electron spectra, γ-ray angular distributions and three parameter (E sub(γ)E sub(γ) time) coincidences. From these experiments information is obtained for states with spin up to I = 13 + and I = 27/2 - , respectively, These states are interpeted within the framework of the cluster-vibration model (CVM) as well as the shell model. (author)

  9. Latest SM results with the ATLAS detector

    CERN Document Server

    Sforza, Federico; The ATLAS collaboration

    2018-01-01

    The precise measurement of SM observables is a key element of the LHC programme, both as a probe of the fundamental properties of Nature and as a tool to improve future experimental and theoretical studies. This talk reviews recent highlights in the measurement of SM processes, including the SM-Higgs properties, performed by the ATLAS collaboration.

  10. Extraction of Sm from Sm-Fe alloys by the glass slag method

    International Nuclear Information System (INIS)

    Saito, Tetsuji; Sato, Hironori; Motegi, Tetsuichi

    2005-01-01

    Application of the glass slag method to the extraction of samarium from Sm-Fe alloys was studied. The magnetic Sm 2 Fe 17 phase was decomposed into the Sm oxide phase and Fe phases by the glass slag method. The Sm oxide phase was extracted by the surrounding molten glass slag material in the glass slag method. The resultant alloys consisted of neither the Sm 2 Fe 17 phase nor the Sm oxide phase. The Sm-Fe alloys were therefore separated into Sm-containing glass slag material and an Fe-B alloy by the glass slag method. This method was found to be suitable for the extraction of Sm from Sm-Fe alloys, as was the case for the extraction of neodymium from Nd-Fe-B alloys

  11. A revision of the Sm-rich region of the Sm-Co system

    International Nuclear Information System (INIS)

    Yuan, Y.; Delsante, S.; Yi, J.; Borzone, G.

    2010-01-01

    Research highlights: → The Sm-rich side of the Sm-Co system has been experimentally reinvestigated using Differential Scanning Calorimetry (DSC), microscope and X-Ray diffraction (XRD) analyses. → Results confirm the existence of the Sm 3 Co and Sm 5 Co 2 phases. → Five invariant reactions have been determined in the Sm-rich region. - Abstract: The Sm-rich side of the Sm-Co system has been experimentally reinvestigated using the differential scanning calorimetry (DSC) method with slow rates of 1 o C/min and 0.5 o C/min as well as microscope and X-ray diffraction (XRD) analyses. Combining the experimental results from DSC, XRD and EPMA (Electron Probe MicroAnalysis) analyses, five invariant reactions have been determined and the existence of the Sm 3 Co and Sm 5 Co 2 phases confirmed. The phase diagram of Sm-Co system has been accordingly modified.

  12. EU Budgetary Dynamics

    DEFF Research Database (Denmark)

    Citi, Manuele

    2013-01-01

    In this article I study the long-term evolution of the main categories of expenditure of the European Union (EU) budget (1984-2011). The aim is to assess the extent to which the EU is affected by a structural form of policy inertia, and to investigate the general pattern of policy stability...... and change in the EU in light of the two models of policy dynamics currently existing in the literature: the incrementalist model and the punctuated equilibrium model. The analysis of long series of original data extracted from the EU budget shows that EU policies do not evolve following an incrementalist...

  13. Luminescence properties of barium--gadolinium-titanate ceramics doped with rare-earth ions (Eu3+ and Tb3+).

    Science.gov (United States)

    Hemasundara Raju, S; Muni Sudhakar, B; Sudhakar Reddy, B; Dhoble, S J; Thyagarajan, K; Nageswara Raju, C

    2014-11-01

    Barium-gadolinium-titanate (BaGd2 Ti4 O12) powder ceramics doped with rare-earth ions (Eu(3+) and Tb(3+)) were synthesized by a solid-state reaction method. From the X-ray diffraction spectrum, it was observed that Eu(3+) and Tb(3+):BaGd2 Ti4 O12 powder ceramics are crystallized in the form of an orthorhombic structure. Scanning electron microscopy image shows that the particles are agglomerated and the particle size is about 200 nm. Eu(3+) - and Tb(3+) -doped BaGd2 Ti4 O12 powder ceramics were examined by energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, photoluminescence and thermoluminescence (TL) spectra. Emission spectra of Eu(3+)-doped BaGd2 Ti4 O12 powder ceramics showed bright red emission at 613 nm ((5)D0 →(7)F2) with an excitation wavelength λ(exci)  = 408 nm ((7)F0 → (5)D3) and Tb(3+):BaGd2 Ti4 O12 ceramic powder has shown green emission at 534 nm ((5)D4 → (7)F5) with an excitation wavelength λ(exci)  = 331 nm (((7)F6 → (5)D1). TL spectra show that Eu(3+) and Tb(3+) ions affect TL sensitivity. Copyright © 2014 John Wiley & Sons, Ltd.

  14. Gd3+-ESR and magnetic susceptibility of GdCu4Al8 and GdMn4Al8

    International Nuclear Information System (INIS)

    Coldea, R.; Coldea, M.; Pop, I.

    1994-01-01

    Gd ESR of GdCu 4 Al 8 and GdMn 4 Al 8 and magnetic susceptibility of GdCu 4 Al 8 , GdMn 4 Al 8 , and YMn 4 Al 8 were measured in the temperature range of 290K--460K and 90K--1050K, respectively. The occurrence of the Mn moment in YMn 4 Al 8 and GdMn 4 Al 8 is strongly correlated with the critical value of d∼2.6 angstrom of the Mn-Mn distance below which the Mn moment is not stable. The experimental data for GdMn 4 Al 8 , compared with the data for the isostructural compounds GdCu 4 Al 8 and YMn 4 Al 8 , show that near the critical value of d, the existence of Mn moment depends not only on the value of d, but also on the local magnetic surroundings. It has been revealed that the magnetic character of Mn moment in YMn 4 Al 8 and GdMn 4 Al 8 changes from an itinerant electron type to a local-moment type with increasing temperature

  15. Radiation characteristics of GD-2 fuel

    International Nuclear Information System (INIS)

    Chrapciak, V.

    2008-01-01

    The assembly WWER-440 type Gd-2 has radial profile of enrichment and has 6 pins with Gd 2 O 3 . The maximal enrichment is 4.4%. Some analyses are done for assembly with flat enrichment (4.4%) and without Gd 2 O 3 . In this article are compared some characteristics (decay heat, some nuclide concentration, photon and gamma sources) for real Gd-2 assembly and for flat 4.4% assembly. The TRITON module (in SCALE 5.1) was used. (Author)

  16. Byg EU om

    DEFF Research Database (Denmark)

    Nedergaard, Peter

    2017-01-01

    Der argumenteres for en række påstande vedrørende en mulig ombygning af EU med henblik på at håndtere den krise, som unionen står i. Grundlæggende for dem alle er, at enten ombygges EU på disse områder, eller også smuldrer samarbejdet. Et internationalt samarbejde som EU kollapser ikke; det mister...

  17. Sierra/SM theory manual.

    Energy Technology Data Exchange (ETDEWEB)

    Crane, Nathan Karl

    2013-07-01

    Presented in this document are the theoretical aspects of capabilities contained in the Sierra/SM code. This manuscript serves as an ideal starting point for understanding the theoretical foundations of the code. For a comprehensive study of these capabilities, the reader is encouraged to explore the many references to scientific articles and textbooks contained in this manual. It is important to point out that some capabilities are still in development and may not be presented in this document. Further updates to this manuscript will be made as these capabilites come closer to production level.

  18. Recent experiments at Brookhaven: level structure of N = 86 isotones 156Yb and 150Gd

    International Nuclear Information System (INIS)

    Sunyar, A.W.

    1980-01-01

    States of the N = 86 isotones 156 Yb and 150 Gd have been studied by means of the 144 Sm( 16 O,4n) 156 Yb, 113 In( 46 Ti,p2n) 156 Yb, and 124 Sn( 30 Si,4n) 150 Gd reactions. Levels have been established to spin 36 h-bar and over 12.5 MeV in excitation in 150 Gd and to beyond spin 25 h-bar in 156 Yb. The systematics of levels in the N = 86 isotones from 150 Gd to 156 Yb are described, and the near-spherical shell model description for states in this region to near spin 30 h-bar is discussed. A T/sub 1/2/ = 6 ns, 72-keV isomeric transition in 156 Yb has been discovered, and an E1 multipolarity is assigned to this transition. The spin-parity of the isomeric state is established as 11 - . 6 figures

  19. Cluster decay of various Gd isotopes from the trans-tin region

    International Nuclear Information System (INIS)

    Sharma, Kanishka; Sharma, Manoj K.; Sawhney, Gudveen; Gupta, Raj K.

    2015-01-01

    Knowing the importance of shell structure of daughter nucleus, the authors studied ground state decay paths of proton-rich 128-132 Gd and other neighboring nuclei 108-116 Xe, 112-120 Ba, 116-124 Ce, 120-124 Nd, and 124-128 Sm on the basis of preformed cluster model (PCM) to explore the region of Sn radioactivity. It is important to note here that, in addition to shell effects the deformations and orientations of nuclei are also anticipated to play an important role in cluster decay process. In order to extend the above study, we apply the same methodology to analyze the influence of nuclear deformations and orientations on the fragmentation path of 128-136 Gd isotopes

  20. Sn(II), −Sm(II)

    African Journals Online (AJOL)

    Preferred Customer

    VCl3, SnCl2⋅2H2O, Sm(NO3)2⋅6H2O and SmCl3⋅6H2O) with slightly excess amounts of nitrilotriacetic acid in DMF resulted in the ... and Sm(III) ions through its three oxygen atoms and the nitrogen atom. The same tetra-dentate coordination ...

  1. (Gd1−xErx)5Si2Ge2 compounds

    Indian Academy of Sciences (India)

    (RE = Ce, Pr, Sm, Tb, Dy, Er, Ho, Y) compounds (Tegus and Dagula 2002; Yang et al 2003; ..... 161K. 164K. 167K. 170K. 173K. 176K. 179K. 182K. 185K. 188K. 191K. 194K. 197K. 200K. Figure 5. Magnetization isotherm curves of (Gd1−x Erx )5Si2Ge2 compounds measured under field of 0–2 T: (a) x = 0, (b) x = 0·05, (c) x ...

  2. Investigation of Gd compounds using synchrotron radiation

    International Nuclear Information System (INIS)

    Tyszka, B.; Szade, J.; Burian, W.; Skorek, G.; Deniszczyk, J.; Sikora, M.; Zajac, D.; Kapusta, Cz.; Matteucci, M.; Bondino, F.; Zacchigna, M.; Zangrando, M.

    2005-01-01

    The electronic structure of ferromagnetic compound GdTiGe has been investigated using element sensitive methods-X-ray absorption spectroscopy (XAS), X-ray magnetic circular dichroism (XMCD) and resonant inelastic X-ray scattering (RIXS). Additionally, another ferromagnet GdTiSi has been studied using XMCD. XMCD revealed a strong dichroic signal at Gd L 2 and L 3 edges, which can be related to polarisation of Gd 5d band. XAS at Ti L 2,3 edges has exhibited a structure which appeared to be in general agreement with the LAPW calculations. RIXS spectra have shown some resonance features for photon energies close to Ti L 2 and Gd M 5 edges

  3. Magnetism at the V/Gd interface

    International Nuclear Information System (INIS)

    Mouketo, L; M'Passi-Mabiala, B; Binggeli, N

    2010-01-01

    Recent experimental investigations into the magnetic properties of V/Gd bilayers have shown that vanadium, which is nonmagnetic in the bulk, can acquire a magnetic moment in such systems. We have performed ab initio pseudopotential calculations to examine the magnetic behavior of V(110)/Gd(0001) bilayers for V layers with thicknesses up to 4 monolayers (ML). We considered both abrupt and atomic intermixed V/Gd interfaces. In both cases, the magnetic moment of the V layer is found to align antiparallel to the moment of the Gd layer, consistent with the experimental observation. However, the magnitude of the V moment at the abrupt interface is considerably smaller than the moments reported experimentally. In the presence of atomic intermixing, instead, substantially larger V moments are found, closer to the experimentally reported moments. On the basis of the calculated atomic and spin resolved density of states, we discuss the possible mechanism responsible for the observed Gd-V antiferromagnetic coupling.

  4. Crystal phase transition in LixNa1-xGdF4 solid solution nanocrystals - Tuning of optical properties

    KAUST Repository

    Bański, Mateusz

    2014-01-01

    The influence of precursor composition on the crystallization of LixNa1-xGdF4 is investigated and discussed. Nanocrystals are prepared from the thermal decomposition of trifluoroacetates in the presence of trioctylphosphine oxide to provide control over particle size. A crystal phase transition from hexagonal to cubic and to tetragonal is observed by increasing lithium trifluoroacetate (Li-TFA) in the solution. Controlling the composition of LixNa1-xGdF4 nanocrystals results in modified crystal field symmetry and emission properties from doped europium (Eu3+) ions. We report that for lithium (Li+) substitution <15%, the hexagonal crystal field is preferred, while the Eu3+ emission is already tuned, whereas at higher Li+ substitution, a phase change takes place and the number of crystalline matrix defects increases which is reflected in the optical properties of Eu3+. From Eu3+ emission properties, the optimum Li+ content is determined to be ∼6.2% in the prepared LixNa1-xGdF4 nanocrystals.

  5. Reforming the EU Budget

    DEFF Research Database (Denmark)

    Citi, Manuele

    The marginal involvement of the EU in redistributive policies and its limited fiscal resources have led to a lack of attention to the EU budget and its determinants. In this paper I analyse an original dataset containing yearly data on the main macrocategories of expenditure and how they have...

  6. Thermophysical properties of Gd{sub 2}Zr{sub 2}O{sub 7} powders prepared by mechanical milling: Effect of homovalent Gd{sup 3+} substitution

    Energy Technology Data Exchange (ETDEWEB)

    Díaz-Guillén, J.A., E-mail: jadiaz@itsaltillo.edu.mx [División de Estudios de Posgrado e Investigación, Instituto Tecnológico de Saltillo, 25280 Saltillo, Coahuila (Mexico); Durá, O.J. [GFMA, Departamento de Física Aplicada, Escuela Técnica Superior de Ingenieros Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Díaz-Guillén, M.R. [Instituto de Investigaciones Eléctricas, 62490 Cuernavaca, Morelos (Mexico); Bauer, E. [Institute of Solid State Physics, Vienna University of Technology, Wien A-1040 (Austria); López de la Torre, M.A. [GFMA, Departamento de Física Aplicada, Escuela Técnica Superior de Ingenieros Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Fuentes, A.F. [Cinvestav Unidad Saltillo, Apartado Postal 663, 25000 Saltillo, Coahuila (Mexico)

    2015-11-15

    This contribution analyzes the thermophysical properties of Gd{sub 1.6}Ln{sub 0.4}Zr{sub 2}O{sub 7} (Ln = La{sup 3+}, Nd{sup 3+}, Sm{sup 3+}, Dy{sup 3+} and Er{sup 3+}) ceramics synthesized at room temperature, by mechanically milling stoichiometric mixtures of high purity oxides. Regardless of chemical composition, powders milled for 27 h show XRD patterns similar to fluorite-type materials. Post-milling thermal treatments at 1500 °C, facilitates the evolution to the ordered pyrochlore derivative for Gd{sub 2}Zr{sub 2}O{sub 7}, and the La{sup 3+}-, Nd{sup 3+}-, and Sm{sup 3+}-containing materials. By contrast, samples containing the smaller lanthanides (Dy{sup 3+} or Er{sup 3+}), maintain the fluorite structure. Thermal conductivity of the as-prepared samples was obtained as a function of temperature, from thermal diffusivity, heat capacity and density values, using sintered pellets. We found that doping has an important effect in lowering Gd{sub 2}Zr{sub 2}O{sub 7} thermal conductivity, with final values ranging from 1.22 to 1.94 W m{sup −1} K{sup −1}; Nd{sup 3+}- and Er{sup 3+}-containing samples represent an optimum combination of defects and disordering of oxygen vacancies that generate the lowest conductivity values of all samples tested. - Highlights: • Gd{sub 2}Zr{sub 2}O{sub 7} doped with different lanthanides was synthesized by mechanical milling. • Smaller Ln{sup 3+} yield fluorites whereas larger lanthanides produce pyrochlores. • Thermophysical properties of the samples were measured as a function of temperature. • All samples show low thermal conductivities, and might find application as TBCs. • Doping is a valid strategy to increase Gd{sub 2}Zr{sub 2}O{sub 7} thermal resistance.

  7. Multicolor Tunable Luminescence Based on Tb3+/Eu3+ Doping through a Facile Hydrothermal Route.

    Science.gov (United States)

    Wang, Chao; Zhou, Ting; Jiang, Jing; Geng, Huiyuan; Ning, Zhanglei; Lai, Xin; Bi, Jian; Gao, Daojiang

    2017-08-09

    Ln 3+ -doped fluoride is a far efficient material for realizing multicolor emission, which plays an important part in full-color displays, biolabeling, and MRI. However, studies on the multicolor tuning properties of Ln 3+ -doped fluoride are mainly concentrated on a complicated process using three or more dopants, and the principle of energy transfer mechanism is still unclear. Herein, multicolor tunable emission is successfully obtained only by codoping with Tb 3+ and Eu 3+ ions in β-NaGdF 4 submicrocrystals via a facile hydrothermal route. Our work reveals that various emission colors can be obtained and tuned from red, orange-red, pink, and blue-green to green under single excitation energy via codoping Tb 3+ and Eu 3+ with rationally changed Eu 3+ /Tb 3+ molar ratio due to the energy transfer between Tb 3+ and Eu 3+ ions in the β-NaGdF 4 host matrix. Meanwhile, the energy transfer mechanism in β-NaGdF 4 : x Eu 3+ /y Tb 3+ (x + y = 5 mol %) submicrocrystals is investigated. Our results evidence the potential of the dopants' distribution density as an effective way for analyzing energy transfer and multicolor-controlled mechanism in other rare earth fluoride luminescence materials. Discussions on the multicolor luminescence under a certain dopant concentration based on single host and wavelength excitation are essential toward the goal of the practical applications in the field of light display systems and optoelectronic devices.

  8. Probing metastable Sm2+ and optically stimulated tunnelling emission in YPO4: Ce, Sm

    DEFF Research Database (Denmark)

    Prasad, Amit Kumar; Kook, Myung Ho; Jain, Mayank

    2017-01-01

    optical stimulation. The work presented here adds further details to the energy levels of the metastable Sm2+ defect and the electron transfer processes by undertaking measurements of a) Sm2+ excitation spectrum through the internal 5D0 → 7F2 emission at 7 K, b) relaxation lifetime of Sm2+ (5D0 state...

  9. Distinguishing a SM-like MSSM Higgs boson from SM Higgs boson ...

    Indian Academy of Sciences (India)

    We explore the possibility of distinguishing the SM-like MSSM Higgs boson from the SM Higgs boson via Higgs boson pair production at future muon collider. We study the behavior of the production cross-section in SM and MSSM with Higgs boson mass for various MSSM parameters tan and A. We observe that at fixed ...

  10. Liquidus surface of Sm-Ga-S system

    International Nuclear Information System (INIS)

    Alieva, O.A.; Aliev, O.M.

    1989-01-01

    Using methods of physicochemic alanalysis for the first time phase diagrams of SmS-Ga 2 S 3 , Sm 2 S 3 -Ga 2 S 3 , SmS-GaS, Sm-GaS, SmGa 2 -SmS, SmGa 2 -GaS, GaS-SmGa 2 S 4 , Sm 3 S 4 -Ga 2 S 3 , Sm 2 S 3 -GaS, Sm 3 S 4 -SmGa 2 S 4 cross sections are studied and the projection of the liquidus surface of the Sm-Ga-S ternary system is plotted. It is found that there exist 6 ternary compounds in the system (SmGa 2 S 4 , SmGaS 3 , SmGa 4 S 7 , Sm 4 GaS 5 , Sm 3 Ga 2 S 5 , Sm 6 Ga 10/3 S 14 ) and, besides, found solid solutions based on GaS, Ga 2 S 3 and SmGa 2 S 4

  11. NMR measurements in milled GdCo2 and GdFe2 intermetallic compounds

    International Nuclear Information System (INIS)

    Tribuzy, C.V.B.; Guimaraes, A.P.; Biondo, A.; Larica, C.; Alves, K.M.B.

    1998-12-01

    We have used the nuclear magnetic resonance technique to study the magnetic and structural properties of the Gd-Co and Gd-Fe metallic systems, starting with the C15 laves phase intermetallic compounds, and submitting them to a high energy milling process. This leads to the amorphization of the samples, as determined by the X-ray diffraction spectra. For the Gd-Co system the NMR study used the 59 Co nucleus; in the Gd-Fe system, 155,157 Gd and 57 Fe were used. Both systems showed segregation of the pure elements, after a few hours of milling. In the Gd-Co system, a single line, of increasing width, was observed in the 59 Co spectrum. In the Gd-Fe system, the 155 Gd and 157 Gd resonances show three lines, arising from electrical quadrupole interaction. With increasing milling time, the lines broaden, and extra lines appear attributed to a cubic phase of Gd; this interpretation is supported by the X-ray analysis of the samples. The 57 Fe NMR spectrum of this system also informs on the direction of magnetization of the samples in the early stages of milling. From 1 h to 7 h of milling, a spectrum of α-Fe was observed. The study of the NMR line intensity as a function of radio frequency (r.f.) power in Gd Co 2 suggests the existence of regions of the samples with different degrees of disorder. We have observed the persistence of NMR signals from the original intermetallic compounds in the samples with up to 10 h and 7 h of milling, respectively, for Gd Co 2 and Gd Fe 2 . (author)

  12. Macrocyclic Gd(3+) complexes with pendant crown ethers designed for binding zwitterionic neurotransmitters.

    Science.gov (United States)

    Oukhatar, Fatima; Meudal, Hervé; Landon, Céline; Logothetis, Nikos K; Platas-Iglesias, Carlos; Angelovski, Goran; Tóth, Éva

    2015-07-27

    A series of Gd(3+) complexes exhibiting a relaxometric response to zwitterionic amino acid neurotransmitters was synthesized. The design concept involves ditopic interactions 1) between a positively charged and coordinatively unsaturated Gd(3+) chelate and the carboxylate group of the neurotransmitters and 2) between an azacrown ether appended to the chelate and the amino group of the neurotransmitters. The chelates differ in the nature and length of the linker connecting the cyclen-type macrocycle that binds the Ln(3+) ion and the crown ether. The complexes are monohydrated, but they exhibit high proton relaxivities (up to 7.7 mM(-1)  s(-1) at 60 MHz, 310 K) due to slow molecular tumbling. The formation of ternary complexes with neurotransmitters was monitored by (1) H relaxometric titrations of the Gd(3+) complexes and by luminescence measurements on the Eu(3+) and Tb(3+) analogues at pH 7.4. The remarkable relaxivity decrease (≈80 %) observed on neurotransmitter binding is related to the decrease in the hydration number, as evidenced by luminescence lifetime measurements on the Eu(3+) complexes. These complexes show affinity for amino acid neurotransmitters in the millimolar range, which can be suited to imaging concentrations of synaptically released neurotransmitters. They display good selectivity over non-amino acid neurotransmitters (acetylcholine, serotonin, and noradrenaline) and hydrogenphosphate, but selectivity over hydrogencarbonate was not achieved. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Triple energy transfer and color tuning in Tb3+ and Eu3+-coactivated apatite-type gadolinium-containing phosphors

    Science.gov (United States)

    Guo, Ning; Liang, Qimeng; Li, Shuo; Ouyang, Ruizhuo; Lü, Wei

    2017-11-01

    A family of apatite-type fluorophosphate phosphors with general formula Sr3Gd(1-m-n)Na(PO4)3F:mTb3+,nEu3+ (SGN:mTb3+,nEu3+) have been synthesized via the high-temperature solid-state reaction method. Triple energy transfer processes from Gd3+ in the host to both Tb3+ and Eu3+, as well as from Tb3+ to Eu3+ have been verified by the photoluminescence spectra. Under the excitation of UV light, both green line from the transitions of Tb3+ and red line origin from the transitions of Eu3+ have been simultaneously observed in a single phase phosphor, which makes a promise for tunable color emissions from yellowish-green through yellow and ultimately to reddish-orange by simply adjusting the Eu3+ content (n) in SGN:0.20Tb3+,nEu3+ phosphors. Additionally, the energy transfer from the Tb3+ to the Eu3+ ions has been demonstrated to be a resonant type via a quadrupole-quadrupole mechanism based on the Dexter's theoretical model, and the energy transfer efficiency increases with an increase in Eu3+ concentration.

  14. Understanding the photoluminescence characteristics of Eu{sup 3+}-doped double-perovskite by electronic structure calculation

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Binita [St. Paul’s Cathedral Mission College, 33/1Raja Rammohan Roy Road, Kolkata 700009 (India); Halder, Saswata; Sinha, T. P. [Department of Physics, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009 (India); Das, Sayantani [Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009 (India)

    2016-05-23

    Europium-doped luminescent barium samarium tantalum oxide Ba{sub 2}SmTaO{sub 6} (BST) has been investigated by first-principles calculation, and the crystal structure, electronic structure, and optical properties of pure BST and Eu-doped BST have been examined and compared. Based on the calculated results, the luminescence properties and mechanism of Eu-doped BST has been discussed. In the case of Eu-doped BST, there is an impurity energy band at the Fermi level, which is formed by seven spin up energy levels of Eu and act as the luminescent centre, which is evident from the band structure calculations.

  15. EU Industrial Policy

    DEFF Research Database (Denmark)

    Pellegrin, Julie; Giorgetti, Maria Letizia; Jensen, Camilla

    Following disregard in the 1980s, industrial policy has recently attracted policy attention at EU level. The objective of this study provided by Policy Department A at the request of the ITRE Committee, is to establish the state of the art of a coordinated and integrated EU industrial policy....... It assesses current initiatives, policies and arrangements and proposes an overview of stakeholders' positions at EU and national levels in order to feed into the debate on how to improve competitiveness and growth in Europe....

  16. The EU and China

    DEFF Research Database (Denmark)

    Zank, Wolfgang

    ” (Shambaugh 2004, 243). He pointed, firstly, at the strong growth in trade relations; the EU also became the largest foreign supplier of technology and equipment, in the form of direct investment, but also through a number of joint technology projects. The EU-China Framework Program became the world’s largest...... common research project. As to political cooperation, numerous meetings have been institutionalised, among them, at the top level an annual EU-China Summit. The contacts have resulted in a number of agreements, for instance on group tourism. According to estimates 100,000 Chinese Students went...

  17. Essentials of EU law

    CERN Document Server

    Reinisch, August

    2012-01-01

    This book explores the history and institutions of the EU, examines the interplay of its main bodies in its legislative process and illustrates the role played by the EU Courts and the importance of fundamental rights. The student is also introduced to the key principles of the internal market, in particular the free movement of goods and the free movement of workers. In addition a number of other EU policies, such as the Common Agricultural Policy, Environmental Protection and Social Policy are outlined, while a more detailed inquiry is made into European competition law.

  18. Governing EU employment policy

    DEFF Research Database (Denmark)

    Sørensen, Eva; Triantafillou, Peter; Damgaard, Bodil

    2015-01-01

    In the European Union (EU), employment policy is a prerogative of the member states. Therefore the EU's ability to govern in this area depends on its capability to involve national governments and relevant stakeholders in a collaborative effort to formulate and implement shared policy objectives....... Drawing an analytical distinction between cooperation, coordination and collaboration, the article analyses the formulation and implementation of EU employment policies. It concludes that while the formulation of policy objectives and the discussion of national policy approaches do involve elements...... of collaboration, the implementation phase mainly consists in the less demanding forms of cooperation and coordination....

  19. Standardization of {sup 153}Sm using anti-coincidence method; Padronizacao do {sup 153}Sm pelo metodo de anti-coincidencia

    Energy Technology Data Exchange (ETDEWEB)

    Laranjeira, Adilson da Silva; Silva, Carlos J. da; Delgado, Jose Ubiratan; Cruz, Paulo A.L. da; Poledna, Roberto; Silva, Ronaldo L. da; Oliveira, Antonio E. de; Gomes, Regio S.; Veras, Eduardo V. de; Araujo, Miriam Taina Ferreira de, E-mail: adilson@ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    {sup 153}Sm was standardized at the Brazilian National Laboratory of Metrology of Ionizing Radiation to provide traceability for measurements in nuclear medicine services and manufacturers of radiopharmaceuticals in Brazil. {sup 153}Sm decays by emission β-γ to {sup 153}Eu, the gamma rays of higher-intensity are 69.7 keV (4.7%) and 103.2 keV (29.2%). The standardization was made by anticoincidence and CIEMAT/NIST methods with uncertainties combined (0.4% and 0.3%) and (0.5% and 0.4%), respectively. The difference between the standardized activities was 0.15%. The uncertainties are consistent with other publications. (author)

  20. Time domain simulation of Gd3+-Gd3+ distance measurements by EPR

    Science.gov (United States)

    Manukovsky, Nurit; Feintuch, Akiva; Kuprov, Ilya; Goldfarb, Daniella

    2017-07-01

    Gd3+-based spin labels are useful as an alternative to nitroxides for intramolecular distance measurements at high fields in biological systems. However, double electron-electron resonance (DEER) measurements using model Gd3+ complexes featured a low modulation depth and an unexpected broadening of the distance distribution for short Gd3+-Gd3+ distances, when analysed using the software designed for S = 1/2 pairs. It appears that these effects result from the different spectroscopic characteristics of Gd3+—the high spin, the zero field splitting (ZFS), and the flip-flop terms in the dipolar Hamiltonian that are often ignored for spin-1/2 systems. An understanding of the factors affecting the modulation frequency and amplitude is essential for the correct analysis of Gd3+-Gd3+ DEER data and for the educated choice of experimental settings, such as Gd3+ spin label type and the pulse parameters. This work uses time-domain simulations of Gd3+-Gd3+ DEER by explicit density matrix propagation to elucidate the factors shaping Gd3+ DEER traces. The simulations show that mixing between the |+½, -½> and |-½, +½> states of the two spins, caused by the flip-flop term in the dipolar Hamiltonian, leads to dampening of the dipolar modulation. This effect may be mitigated by a large ZFS or by pulse frequency settings allowing for a decreased contribution of the central transition and the one adjacent to it. The simulations reproduce both the experimental line shapes of the Fourier-transforms of the DEER time domain traces and the trends in the behaviour of the modulation depth, thus enabling a more systematic design and analysis of Gd3+ DEER experiments.

  1. High-efficient, bicolor-emitting GdVO4:Dy3+ phosphor under near ultraviolet excitation

    International Nuclear Information System (INIS)

    Lu, Jinjin; Zhou, Jia; Jia, Huayu; Tian, Yue

    2015-01-01

    Bicolor emitting GdVO 4 :Dy 3+ phosphor with short columniation-shape was prepared via a simple co-precipitation process. The optimal doping concentration for obtaining maximal luminescent intensity was confirmed to be 0.3 mol% and the electric dipole–dipole interaction is responsible for concentration quenching of Dy 3+ emission in GdVO 4 phosphor. In order to evaluate the luminescent performance of as-prepared phosphor, the luminescent efficiency and color coordinates were studied. The results show that luminescent efficiency of this phosphor is very high under near UV excitation and twice times higher than commercial Y 2 O 2 S:Eu 3+ phosphor. In addition, the color coordinates for optimal Dy 3+ concentration are (0.339, 0.379), which are close to equal energy point. Therefore, the GdVO 4 :Dy 3+ phosphor may have potential application for solid state lighting.

  2. EU-retten 1

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig; Nielsen, Poul Runge

    Udover en introduktion til EU-retten, herunder dens institutioner og retskilderne, indeholder bogen en grundig analyse af EF-traktatens regler om fri bevægelighed for varer, personer, tjenesteydelser og kapital....

  3. EU Nuclear vs. Fukushima

    International Nuclear Information System (INIS)

    Poncelet, Jean-Pol

    2011-01-01

    Conclusions: • The Fukushima-Daiichi accident represents an opportunity for the nuclear industry to demonstrate its ability to learn from experience through “a continuous improvement strategy”; • Inside the EU: which legal framework for nuclear safety - harmonisation of licensing procedures - EU-level reactor design clearance?; • No way forward without public support: how to address, explain, convince?; • Greater cooperation between industry and international organizations: FORATOM available to contribute

  4. EU Labour Law

    DEFF Research Database (Denmark)

    Nielsen, Ruth

    The focus in this book is upon EU labour law and its interaction with national and international labour law. The book provides an analysis of the framework and sources of European labour law. It covers a number of substantive topics, notably collective labour law, individual employment contracts......, discrimination on grounds of sex and on other grounds, free movement of persons, restructuring of enterprises, working environment and enforcement of rights derived from EU labour law....

  5. Restoring EU competitiveness

    OpenAIRE

    Berndt, M.; Muent, G.; Revoltella, D.; Bending, T.; Calthrop, E.; Dunnett, G.; Piovesan, L.; Scatasta, M.; Stölting, S.; Välila, T.

    2014-01-01

    With the advent of the digital revolution in the 1990s, productivity growth in the EU began to slip behind that in the US and other leading trading partners. This trend has undermined the comparative ability of European firms to compete and to provide rewarding jobs and a high standard of living. Low comparative productivity and misallocation of investment, alongside many structural weaknesses, help explain why the global crisis hit Europe so hard, and why EU-wide recovery still presents such...

  6. EU Labour Law

    DEFF Research Database (Denmark)

    Nielsen, Ruth

    The focus in this book is upon EU labour law and its interaction with national and international labour law. The book provides an analysis of the framework and sources of European labour law. It covers a number of substantive topics, notably collective labour law, individual employment contracts,......, discrimination on grounds of sex and on other grounds, free movement of persons, restructuring of enterprises, working environment and enforcement of rights derived from EU labour law....

  7. الفائق التوصيل الكهربائي SmBa2Cu3O7-δ على خواص المركب Eu و Sn و Zn - تأثير التعويض الجزئي للعناصر

    OpenAIRE

    أحمد محمد كاظم; علي عبد الكريم دهش

    2000-01-01

    تمت دراسة تأثير التعويض الجزئي لعناصرEu  و Sr و Zn في كل من العناصرSm و Ba و Cu  على الترتيب على خواص المركب SmBa2Cu3O7-d ذي التوصيلية الكهربائيةالفائقة في درجات الحرارة العالية. أظهرت النتائج أن التعويض الجزئي لعنصر اليوروبيوم Eu في عنصر السماريوم Sm  أبقى المركب محافظا على هيئة تركيب المعيني القائم بينما أدى إلى زيادة درجة الحرارة الحرجة من K 88 الى 107 K عندما تزداد قيمة التعويض من 0 الى 0.2. أما التعويض الجزئي لعنصر السترونتيوم Sr في عنصر الباريومBa بنسب  0 و 0.1 و 0.2 و 0.3 و 0.4  و 0.5 ...

  8. SM-1 negative ion source

    International Nuclear Information System (INIS)

    Huang Zhenjun; Wang Jianzhen

    1987-01-01

    The working principle and characteristics of SM-1 Negative Ion Source is mainly introduced. In the instrument, there is a device to remove O 3 . This instrument can keep high density of negative ions which is generated by the electrical coronas setting out electricity at negative high voltage and can remove the O 3 component which is harmful to the human body. The density of negative ions is higher than 2.5 x 10 6 p./cm 3 while that of O 3 components is less than 1 ppb at the distance of 50 cm from the panel of the instrument. The instrument sprays negative ions automatically without the help of electric fan, so it works noiselessly. It is widely used in national defence, industry, agriculture, forestry, stock raising, sidelines and in the places with an equipment of low density of negative ion or high concentration of O 3 components. Besides, the instrument may also be used to treat diseases, to prevent against rot, to arrest bacteria, to purify air and so on

  9. checkCIF/PLATON report Datablock: sm

    Indian Academy of Sciences (India)

    Sm (C12 H12 N2) (C15 H11. O2)3. Sum formula. C57 H45 N2 O6 Sm. C57 H45 N2 O6 Sm. Mr. 1004.31. 1004.31. Dx,g cm-3. 1.430. 1.430. Z. 8. 8. Mu (mm-1). 1.313. 1.313. F000. 4088.0. 4088.0. F000'. 4088.21 h,k,lmax. 24,26,31. 24,26,31. Nref. 10796. 10767. Tmin,Tmax. 0.538,0.674. 0.572,0.747. Tmin'. 0.514. Correction ...

  10. Evaluation of Gd and Gd{sup 159} as new approaches for cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, I.; Neves, M.J., E-mail: nevesmj@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Grupo de Desenvolvimento de Radiofarmacos; Santos, R.G., E-mail: santosr@cdtn.br [Instituto Nacional de Ciencia e Tecnologia em Medicina Molecular (INCT-MM), Belo Horizonte, MG (Brazil)

    2011-07-01

    Metal compounds have shown many biological activities and have been successfully used as anticancer agents such cisplatin. Actually gadolinium (Gd) complexed with a porphyrin Motexafin (MGd) has been investigated as redox-active compound for treatment of cancer. 1{sup 59G}d decays by beta emission with an energy of 970 keV and half-life of 18.59 hours. The de-excitation can be via gamma ray and internal conversion electron emission followed by auger electrons and x rays. Considering all of this 1{sup 59G}d could be a interesting radionuclide to be as a radio therapeutical agent. The aims of this works were to evaluate the cytotoxicity of Gd and 1{sup 59G}d on malignant brain tumors such as glioblastoma multiform, the most frequent brain tumors which has a very poor prognosis. For this purpose, it was used human glioblastoma cell lines T98 (mutant p53) and U87 (wild-type p53) to investigate the cytotoxicity of gadolinium on cell metabolism by MTT assay and also morphological changes, chromatin condensation by DAPI assay and ROS generation. Gadolinium was able to decrease cell viability, the cells presented morphological changes like round shapes and blebs formation after cell treatment with 5x10{sup -6}M of Gd. Nuclear changing and ROS generation occurred in a dose dependent way indicating the cytotoxic effect of Gd. Treatment with 1{sup 59G}d increased all of changes observed with treatment with Gd. These results state for an additive effect of metal toxicity and radioactivity inducing ROS generation as the main mechanism of anti tumoral action of 1{sup 59G}d. The results obtained indicated that the radioactive analogues of Gd have increased cytotoxic effects and gadolinium can be a metal of choice for development of new drugs for cancer treatment. (author)

  11. Definition of an intramolecular Eu-to-Eu energy transfer within a discrete [Eu2L] complex in solution.

    Science.gov (United States)

    Nonat, Aline; Regueiro-Figueroa, Martín; Esteban-Gómez, David; de Blas, Andrés; Rodríguez-Blas, Teresa; Platas-Iglesias, Carlos; Charbonnière, Loïc J

    2012-06-25

    Ligand L, based on two do3a moieties linked by the methylene groups of 6,6'-dimethyl-2,2'-bipyridine, was synthesized and characterized. The addition of Ln salts to an aqueous solution of L (0.01 M Tris-HCl, pH 7.4) led to the successive formation of [LnL] and [Ln(2)L] complexes, as evidenced by UV/Vis and fluorescence titration experiments. Homodinuclear [Ln(2)L] complexes (Ln = Eu, Gd, Tb, Yb, and Lu) were prepared and characterized. The (1)H and (13)C NMR spectra of the Lu and Yb complexes in D(2)O solution (pD = 7.0) showed C(1) symmetry of these species in solution, pointing to two different chemical environments for the two lanthanide cations. The analysis of the chemical shifts of the Yb complex indicated that the two coordination sites present square antiprismatic (SAP) coordination environments around the metal ions. The spectroscopic properties of the [Tb(2)L] complex upon ligand excitation revealed conventional behavior with τ(H2O) = 2.05(1) ms and ϕ(H2O) = 51%, except for the calculation of the hydration number obtained from the luminescent lifetimes in H(2)O and D(2)O, which pointed to a non-integer value of 0.6 water molecules per Tb(III) ion. In contrast, the Eu complex revealed surprising features such as: 1) the presence of two and up to five components in the (5)D(0)→(7)F(0) and (5)D(0)→(7)F(1) emission bands, respectively; 2) marked differences between the normalized spectra obtained in H(2)O and D(2)O solutions; and 3) unconventional temporal evolution of the luminescence intensity at certain wavelengths, the intensity profile first displaying a rising step before the occurrence of the expected decay. Additional spectroscopic experiments performed on [Gd(2-x)Eu(x)L] complexes (x = 0.1 and 1.9) confirmed the presence of two distinct Eu sites with hydration numbers of 0 (site I) and 2 (site II), and showed that the unconventional temporal evolution of the emission intensity is the result of an unprecedented intramolecular Eu-to-Eu

  12. Electrochemical properties of composite cathodes using Sm doped layered perovskite for intermediate temperature-operating solid oxide fuel cell

    Science.gov (United States)

    Baek, Seung-Wook; Azad, Abul K.; Irvine, John T. S.; Choi, Won Seok; Kang, Hyunil; Kim, Jung Hyun

    2018-02-01

    SmBaCo2O5+d (SBCO) showed the lowest observed Area Specific Resistance (ASR) value in the LnBaCo2O5+d (Ln: Pr, Nd, Sm, and Gd) oxide system for the overall temperature ranges tested. The ASR of a composite cathode (mixture of SBCO and Ce0.9Gd0.1O2-d) on a Ce0.9Gd0.1O2-d (CGO91) electrolyte decreased with respect to the CGO91 content; the percolation limit was also achieved for a 50 wt% SBCO and 50 wt% CGO91 (SBCO50) composite cathode. The ASRs of SBCO50 on the dense CGO91 electrolyte in the overall temperature range of 500-750 °C were relatively lower than those of SBCO50 on the CGO91 coated dense 8 mol% yttria-stabilized zirconia (8YSZ) electrolyte for the same temperature range. From 750 °C and for all higher temperatures tested, however, the ASRs of SBCO50 on the CGO91 coated dense 8YSZ electrolyte were lower than those of the CGO91 electrolyte. The maximum power densities of SBCO50 on the Ni-8YSZ/8YSZ/CGO91 buffer layer were 1.034 W cm-2 and 0.611 W cm-2 at 800 °C and 700 °C.

  13. Systematic and in situ energy dispersive X-ray diffraction investigations on the formation of lanthanide phosphonatobutanesulfonates: Ln(O(3)P-C(4)H(8)-SO(3))(H(2)O) (Ln = La-Gd).

    Science.gov (United States)

    Feyand, Mark; Näther, Christian; Rothkirch, André; Stock, Norbert

    2010-12-06

    Using the flexible linker H(2)O(3)P-C(4)H(8)-SO(3)H (H(3)L) and rare earth ions Ln(3+) (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd) we were able to synthesize the new isostructural inorganic organic hybrid compounds Ln(O(3)P-C(4)H(8)-SO(3))(H(2)O). High-throughput experiments were employed to study the influence of the molar ratios Ln:H(3)L and pH on the product formation. The crystal structure of the compounds Sm(O(3)P-C(4)H(8)-SO(3))(H(2)O) (1) and Pr(O(3)P-C(4)H(8)-SO(3))(H(2)O) (2) were determined by single crystal diffraction. The structures are built up from chains of edge-sharing LnO(8)-polyhedra that are connected by the phosphonate and sulfonate groups into layers. These layers are linked by the -(CH(2))(4)- group to form a three-dimensional framework. The synthesis of compound 1 was scaled up in a conventional oven as well as in a microwave reactor system. A modification of a microwave reactor system allowed its integration into the beamline F3 at HASYLAB, DESY, Hamburg. The crystallization was investigated in situ by means of energy dispersive X-ray diffraction using conventional as well as microwave heating methods applying temperatures varying from 110 to 150 °C. The formation of Sm(O(3)P-C(4)H(8)-SO(3))(H(2)O) takes place in two steps. In the first step a crystalline intermediate was observed, which transforms completely into compound 1. The method by Sharp and Hancock was used to determine the rate constants, reaction exponents, and the Arrhenius activation energy for both reaction steps. Comparing both heating methods, microwave heating leads to fully crystallized reaction product after shorter reaction times, but neither the temperature nor the heating method has significant influence on the induction time.

  14. Electronic configurations of Sm2+ in SmS and SmB6, and electrical properties

    International Nuclear Information System (INIS)

    Oudet, X.

    1977-01-01

    In Dirac's theory the 4f shell is divided into two subshells: 4f/sub 5/2/ with six quantum states and 4f/sub 7/2/ with eight quantum states. Assuming that these two subshells can be filled up successively, we had successfully obtained the saturation magnetic moment of the garnets Ln 3 Fe 5 O 12 . This study is devoted to establish the role of the subshells in the case of SmS phase transformation under pressure P. Particularly for Sm 2+ the low spin configuration 4f/sub 5/2/ 6 4f/sub 7/2/ 0 which with six 4f electrons has a filled subshell 4f/sub 5/2/ leading to a zero magnetic moment. But as the insulator in equilibrium metal I in equilibrium M transition exhibited with this phase transition, is explained through a valence change, we first consider the localized electron model proposed in the case of Fe 3 O 4 to show that large variations of electrical resistivity of SmS and SmB 6 also can be understood through this model. A result which allows us to consider the ion Sm 2+ in both phases of SmS. 1 figure

  15. Two-step gamma cascades following thermal neutron capture in Gd-155,Gd-157

    Czech Academy of Sciences Publication Activity Database

    Valenta, S.; Bečvář, F.; Kroll, J.; Krtička, M.; Tomandl, Ivo

    2015-01-01

    Roč. 92, č. 6 (2015), s. 064321 ISSN 0556-2813 R&D Projects: GA ČR GA13-07117S; GA MŠk(CZ) LM2011019 Institutional support: RVO:61389005 Keywords : Ge detector * scattering * Gd-158 * Gd-157 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.146, year: 2015

  16. Lobbyisme i EU

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    Lobbyisme i EU giver en generel teoretisk tilgang til lobbyisme og bruger EU som eksempel. Den europæiske drøm er at blive verdens stærkeste økonomi, men alligevel findes udbredt markedsbeskyttelse og statsstøtte. Det nye bidrag i denne bog er en tværfaglig tilgang, der fremhæver lobbyisme og...... institutioner og interessegruppers betydning for påvirkning af de politiske beslutningstagere i EU. Argumentet er, at markedsindgreb og manglende frihandel skyldes ureguleret lobbyisme. Der mangler simpelthen regler, der definerer, hvad lobbyister må og ikke må i EU. Uden lovgivning på området er der stor...... risiko for misbrug af systemet til skade for forbrugere, skatteydere og den økonomiske vækst. Hvis ikke EU sætter effektivt ind mod lobbyisme og økonomisk skadelig omfordeling, så vælges vejen mod planøkonomi og korruption, hvor pengene havner i de forkerte lommer. Da kan drømmen om at blive verdens...

  17. Giant magnetocaloric effect in Gd5(Si2Ge2 alloy with low purity Gd

    Directory of Open Access Journals (Sweden)

    Cleber Santiago Alves

    2004-12-01

    Full Text Available Gd5(Ge1-xSi x, x < 4 based alloys are potential candidates for magnetic refrigeration in the range ~20 - ~290 K. However, one of the greatest obstacles for the use of that technology in large scale is the utilization of high pure Gd metal (99.99 wt. (% to produce the GdGeSi alloys, since the impurity elements decrease the intensity of the magnetocaloric effect (EMC¹. In this work, we prove that annealing of the Gd5Ge2Si2 can promote remarkable values for the EMC in comparison to those obtained for the alloy with high pure Gd. Also, the as cast alloy and the annealed alloy are not monophasic, but have at least two crystalline phases in their microstructure. Results for X-ray analysis, optical and electronic microscopy and magnetization measurements are reported.

  18. Provably-secure (Chinese government) SM2 and simplified SM2 key exchange protocols.

    Science.gov (United States)

    Yang, Ang; Nam, Junghyun; Kim, Moonseong; Choo, Kim-Kwang Raymond

    2014-01-01

    We revisit the SM2 protocol, which is widely used in Chinese commercial applications and by Chinese government agencies. Although it is by now standard practice for protocol designers to provide security proofs in widely accepted security models in order to assure protocol implementers of their security properties, the SM2 protocol does not have a proof of security. In this paper, we prove the security of the SM2 protocol in the widely accepted indistinguishability-based Bellare-Rogaway model under the elliptic curve discrete logarithm problem (ECDLP) assumption. We also present a simplified and more efficient version of the SM2 protocol with an accompanying security proof.

  19. Characterization of magnetic property of double-perovskite (Sr{sub 2−x}Gd{sub x})FeMoO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Q., E-mail: zhangqin@sdjtu.edu.cn [School of Science, Shandong Jiaotong University, Jinan 250357 (China); Xu, Z.F.; Wang, L.F. [School of Science, Shandong Jiaotong University, Jinan 250357 (China); Cheng, G. [School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China); Yuan, S.J. [School of Science, Shandong Jiaotong University, Jinan 250357 (China); Rao, G.H., E-mail: rgh@guet.edu.cn [School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China)

    2015-04-15

    Highlights: • Structural distortion is introduced into (Sr{sub 2−x}Gd{sub x})FeMoO{sub 6}. • Curie temperature of (Sr{sub 2−x}Gd{sub x})FeMoO{sub 6} exhibits an non-monotonic evolution. • Contrary to the results of (SrEu)FeMoO{sub 6}, the moment of Gd{sup 3+} is parallel with that of Fe{sup 3+} in our case. • The magnetic behavior of rare-earth elements in Sr{sub 2}FeMoO{sub 6} differs to large degree. - Abstract: Structural and magnetic properties of rare-earth doped (Sr{sub 2−x}Gd{sub x})FeMoO{sub 6} compounds (x = 0, 0.05, 0.1, 0.13 and 0.15) have been investigated. All the compounds are of single phase and belong to the space group I4/m. Because of the small size of Gd{sup 3+} ion (compared to that of Sr{sup 2+} ion), obvious structural distortion is introduced in the compounds and imposes an important influence on the magnetic property of (Sr{sub 2−x}Gd{sub x})FeMoO{sub 6}. The competing interaction between structural distortion and electron injection results in a non-monotonic evolution of the Curie temperature (T{sub C}): T{sub C} decreases firstly and then increases, with a minimum value at x ≈ 0.07. Contrary to the magnetic behavior of Eu{sup 3+} ion in (SrEu)FeMoO{sub 6} compound, the long-range ordered Gd{sup 3+} moment is parallel to that of Fe{sup 3+} ion at low temperature, and the contribution of the dopant to the saturation magnetization of (Sr{sub 2−x}Gd{sub x})FeMoO{sub 6} is 6.75–7.15 μ{sub B} per Gd{sup 3+} ion, which is comparable to the magnetic moment of a free Gd{sup 3+} ion (7.0 μ{sub B}). Above results indicate that although the rare earth elements exhibit similar chemical and optical character, their magnetic behavior in Sr{sub 2}FeMoO{sub 6} compound differs to a large degree.

  20. EU and Vietnam

    DEFF Research Database (Denmark)

    Kokko, Ari

    This paper discusses the changing relationship between the EU and Vietnam, and asks whether there is a shift from a “parental” to a “competitive” relationship. The focus of the paper is on the shift from aid to trade as the main interface between the EU and Vietnam. Aid relationships are often...... understood as hierarchical, linking a benevolent donor to a needy recipient, whereas commercial relationships are typically expected to involve a more competitive relationship. However, we argue that the bilateral relationship was never a “parental” one, even at the time when Vietnam’s relation to the EU...... was limited to aid. The reason is largely Vietnam’s historical experiences from the aid relationship with the Soviet Union, which created dependence and eventually an economic crisis when aid flows dried up in the late 1980s. Instead, there has been substantial tension between the donor community and Vietnam...

  1. Magnetic ordering of GdMn2

    International Nuclear Information System (INIS)

    Ouladdiaf, B.; Ritter, C.; Ballou, R.; Deportes, J.

    1999-01-01

    Complete text of publication follows. GdMn 2 crystallizes in the C15 cubic Laves phase structure. Within this structure Mn atoms lie at the vertices of regular tetrahedra stacked in the diamond arrangement connected by sharing vertices, leading to a strong geometric frustration. An antiferromagnetic magnetic order sets in below T N ∼ 105 K. It gives rise to a large magnetovolume effect (ΔV/V ∼ 1%). Thermal expansion data show two anomalies at 105 K and 35 K. The second anomaly was often interpreted as the ferromagnetic ordering of Gd sublattice. Moessbauer data indicate however, that Gd sublattice orders at T N ∼ 105 K as the Mn moments. Elastic neutron scattering measurements were performed using short wavelength neutron beam (λ = 0.5 A) on D9 at ILL. No magnetic contribution to the nuclear peaks was found excluding thereby any K = [0 0 0] component. However antiferromagnetic peaks indexed by a propagation vector [2/3 2/3 0] were observed leading to a non collinear magnetic arrangement of both Mn and Gd sublattices. The results are discussed by invoking the geometric frustration associated with the Mn atomic packing and the singlet state of the Gd ions. (author)

  2. The expanding EU

    DEFF Research Database (Denmark)

    Zank, Wolfgang

    identity in terms of particular cultural traditions. However, in spite of their diversity, the EU-member countries are united by their adherence to the principles of democracy, rule by law and human rights. Countries which do not share this basic consensus would not be accepted as members, nor is it likely...... that they would apply for it. An essential part is the willingness of member states to accept a reduction of national sovereignty on some important policy fields. The EU project is basically about lifting the principles of democracy and rule by law on the international level, most and foremost among the member...

  3. Thermal properties of UO2 - Gd2O3 fuel

    International Nuclear Information System (INIS)

    Kim, G. S.; Yang, J. H.; Kang, K. W.; Kim, Y. M.; Song, G. W.

    2000-01-01

    The thermal properties (thermal conductivity, oxygen potential and thermal expansion) of UO 2 -Gd 2 O 3 fuels were measured by the laser-flash, TGA and dilatometry method. The thermal conductivity decreased with Gd content, but the oxygen potential and thermal expansion increased with Gd content. Substitution of Gd +3 ion in UO 2 structure increases the scattering site for thermal phonon propagation and thereby decreases the thermal conductivity. The oxygen potential of Gd-doped UO 2 increase mainly because the Gd +3 ions, which are inert to oxidation, make it difficult for oxygen interstitials to access just near them

  4. Gd(III)-nanodiamond conjugates for MRI contrast enhancement

    Science.gov (United States)

    Manus, Lisa M.; Mastarone, Daniel J.; Waters, Emily A.; Zhang, Xue-Qing; Schultz-Sikma, Elise A.; MacRenaris, Keith W.; Ho, Dean

    2010-01-01

    A Gd(III)-nanodiamond conjugate [Gd(III)-ND] was prepared and characterized, enabling detection of nanodiamonds by MR imaging. The Gd(III)-ND particles significantly reduced the T1 of water protons with a per-Gd(III) relaxivity of 58.82 ± 1.18 mM−1s−1 at 1.5 Tesla (60 MHz). This represents a tenfold increase compared to the monomer Gd(III) complex (r1 = 5.42 ± 0.20 mM−1s−1) and is among the highest per-Gd(III) relaxivities reported. PMID:20038088

  5. High-pressure structural behavior of GdAlO3 and GdFeO3 perovskites

    International Nuclear Information System (INIS)

    Ross, N.L.; Zhao, J.; Angel, R.J.

    2004-01-01

    The orthorhombic perovskites, GdAlO 3 and GdFeO 3 , have been studied using single-crystal X-ray diffraction up to 8.52 and 8.13GPa, respectively, in a diamond anvil cell at 298K. The evolution of the structures of GdAlO 3 and GdFeO 3 involves compression of both the GdO 12 and the octahedral (AlO 6 and FeO 6 ) sites. The compression of the GdO 12 site is anisotropic in both perovskites, with the four longest Gd-O distances compressing more than the eight shorter Gd-O bond lengths, resulting in a decrease in the distortion of GdO 12 with pressure. In GdAlO 3 , the GdO 12 site is less compressible than the AlO 6 site, resulting in an increase of both the interoctahedral Al-O1-Al and Al-O2-Al angles with increasing pressure. Thus GdAlO 3 perovskite becomes less distorted with increasing pressure. In GdFeO 3 , the GdO 12 site displays a similar compressibility as the FeO 6 site, with little change in the Fe-O2-Fe angle with pressure but an increase of the Fe-O1-Fe tilting angle. Thus GdFeO 3 perovskite becomes less distorted with increasing pressure, but the change is not as pronounced as GdAlO 3 . The high-pressure behavior of GdAlO 3 and GdFeO 3 is similar to orthorhombic YAlO 3 perovskite but contrasts with orthorhombic CaSnO 3 , which becomes more distorted with increasing pressure

  6. Medium-spin levels and the character of the 20.4 ns 13/2+ isomer in 145Gd

    International Nuclear Information System (INIS)

    Pakkanen, A.; Muhonen, J.; Piiparinen, M.

    1981-06-01

    Levels of the N = 81 nucleus 145 Gd have been investigated by in-beam γ-ray and conversion electron spectroscopy with the 144 Sm( 3 He,2n) reaction. Fourteen new low- and medium-spin states between 1.0 and 2.4 MeV excitation, the known yrast levels up to spin (21/2) + , five other high-spin non-yrast states and a new 20.4 ns (13/2) + isomer at 2200.2 keV in 145 Gd have been observed. The isomer decays via a fast 927.3 keV E3 transition with B(E3) = 48 +- 7 W.u. Another weaker decay branch is a mixed, strongly hindered E1+M2+E3 transition to the νhsub(11/2)sup(-1) state. We propose an octupole νfsub(7/2)jsub(0)sup(-2)x3 - main configuration for the isomer, analogous to the 997 keV (13/2) + isomer in 147 Gd. The levels of 145 Gd are discussed on the basis of the spherical shell model. (author)

  7. EU Food Law Handbook

    NARCIS (Netherlands)

    Meulen, van der B.M.J.

    2014-01-01

    The twenty-first century has witnessed a fundamental reform of food law in the European Union, to the point where modern EU food law has now come of age. This book presents the most significant elements of these legal developments with contributions from a highly qualified team of academics and

  8. EU Agro Biogas Project

    NARCIS (Netherlands)

    Amon, T.; Mayr, H.; Eder, M.; Hobbs, P.; Rao Ravella, S.; Roth, U.; Niebaum, A.; Doehler, H.; Weiland, P.; Abdoun, E.; Moser, A.; Lyson, M.; Heiermann, M.; Plöchl, M.; Budde, J.; Schattauer, A.; Suarez, T.; Möller, H.; Ward, A.; Hillen, F.; Sulima, P.; Oniszk-Polplawska, A.; Krampe, P.; Pastorek, Z.; Kara, J.; Mazancova, J.; Dooren, van H.J.C.; Wim, C.; Gioelli, F.; Balsari, P.

    2009-01-01

    EU-AGRO-BIOGAS is a European Biogas initiative to improve the yield of agricultural biogas plants in Europe, to optimise biogas technology and processes and to improve the efficiency in all parts of the production chain from feedstock to biogas utilisation. Leading European research institutions and

  9. EU-retten 2

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig; Nielsen, Poul Runge

    Bogen indeholder en gennemgang af en række generelle problemstillinger vedrørende harmoniseringen indenfor EU samt en nærmere analyse af harmoniseringen på en række udvalgte områder: selskabsret, skatteret, finansielle tjenesteydelser samt den tekniske harmonisering der skal sikre varernes fri be...

  10. Competition in EU banking

    NARCIS (Netherlands)

    De Jonghe, Olivier; Diepstraten, Maaike; Schepens, Glenn; Beck, Thorsten; Casu, Barbara

    2017-01-01

    This chapter discusses recent EU-wide movements in bank competition and concentration. We start with a concise overview of the most frequently used competition and concentration measures. Given that different measures may capture different aspects of bank competition, we focus on the differences and

  11. EU-PIL

    DEFF Research Database (Denmark)

    Lookofsky, Joseph; Hertz, Ketilbjørn

    Now in a Second Edition comprising the Brussels I Regulation “recast”, as well as other key EU legislation and case law, this book brings together principles of juridical jurisdiction, choice of law, recognition of judgments and commercial arbitration. It shows the interrelationship of the rules...

  12. Performing the EU Referendum

    DEFF Research Database (Denmark)

    Moeran, Brian

    2016-01-01

    This editorial makes use of the EU Referendum to discuss the presence of magic in contemporary societies. It analysis magic in terms of magicians, magical representations, and magical rites – as originally expounded by Malinowski and Mauss – and argues that magic is to be found not only in politi...

  13. Unoccupied surface electronic structure of Gd(0001)

    International Nuclear Information System (INIS)

    Li, D.; Dowben, P.A.; Ortega, J.E.; Himpsel, F.J.

    1994-01-01

    The unoccupied surface electronic structure of Gd(0001) was investigated with high-resolution inverse-photoemission spectroscopy. An empty surface state near E F is observed at bar Γ. Two other surface-sensitive features are also revealed at 1.2 and 3.1 eV above the Fermi level. Hydrogen adsorption on Gd surfaces was used to distinguish the surface-sensitive features from the bulk features. The unoccupied bulk-band critical points are determined to be Γ 3 + at 1.9 eV and A 1 at 0.8 eV

  14. Distinguishing a SM-like MSSM Higgs boson from SM Higgs boson ...

    Indian Academy of Sciences (India)

    mass for various MSSM parameters tan β and mA. We observe that at fixed CM energy, in the SM, the total cross-section increases with the increase in Higgs boson mass whereas this trend is reversed for the MSSM. The changes that occur for the MSSM in comparison to the SM predictions are quantified in terms of the ...

  15. Phase equilibria and crystal chemistry of the CaO-½Gd2O3-CoOz system at 885 °C in air

    Science.gov (United States)

    Wong-Ng, W.; Laws, W.; Lapidus, S. H.; Ribaud, L.; Kaduk, J. A.

    2017-10-01

    The CaO-½Gd2O3-CoOz system prepared at 885 °C in air consists of two thermoelectric calcium cobaltate compounds, namely, the 2D thermoelectric oxide solid solution, (Ca3-xGdx)Co4O9-z (0 ≤ x ≤ 0.42) which has a misfit layered structure, and the 1D Ca3Co2O6 compound which consists of chains of alternating CoO6 trigonal prisms and CoO6 octahedra. Ca3Co2O6 was found to be a point compound. In the peripheral binary systems, Gd was not present in the Ca site of CaO, while a small solid solution region was identified for (Gd1-xCax)O(3-z)/2 (0 ≤ x ≤ 0.075). A solid solution region of distorted perovskite, (Gd1-xCax)CoO3-z (0 ≤ x ≤ 0.24, space group Pnma) was established. The structure of a member of the solid solution, (Gd0.92Ca0.08)CoO3-z, was determined using high resolution synchrotron radiation. A ternary oxide compound CaGdCoO4-z which has an orthorhombic structure (Bmab) was found to be stable at this temperature. Five solid solution tie-line regions and six three-phase regions were determined in the CaO-½Gd2O3-CoOz system. A comparison of the phase diagrams of the CaO-½R2O3-CoOz (R = La, Sm and Gd) systems is provided.

  16. The EU's Convergence Dilemma

    Directory of Open Access Journals (Sweden)

    Notermans Ton

    2015-02-01

    Full Text Available As economic stagnation continues to mark the EU in the fifth year of the euro zone crisis, political support for integration is waning. The European Parliament elections of 2014 returned a hitherto unparalleled number of Eurosceptic MEPs, with EU-critical parties becoming the largest ones in several Member States. Much of this Euroscepticism is driven by economic polarisation between core and peripheral countries. While an increasing number of voters in the northwestern creditor countries resent having to foot the bill for what they consider economic mismanagement in the periphery, voters in peripheral countries increasingly rebel against what they deem to be an economically catastrophic Diktat from Germany and its allies. Continued political support for European integration will hinge on successful income convergence in the EU but the current dilemma is that such policies might not be politically feasible. Periods of rapid convergence would seem to suggest that success depends on two main policy strategies. First, a monetary policy that promotes credit for productive purposes, leaves inflation control to other instruments, and employs selective credit rationing to prevent asset booms. Second, a vertical industrial policy prioritising selected industrial sectors. The first policy conflicts with the present framework of euro zone monetary policy, but that framework was only installed in the first place because many peripheral countries were desperately in search of an external constraint on domestic distributional conflict. Industrial policies, in turn, require a sufficient degree of state autonomy from business elites in order to be effective, but it is highly questionable whether most states in the EU possess such autonomy. Though there are, as yet hesitant, signs of a reorientation of both monetary and cohesion policy in the EU, the question of the institutional and political preconditions for their successful implementation has been largely

  17. The Cloud2SM Project

    Science.gov (United States)

    Crinière, Antoine; Dumoulin, Jean; Mevel, Laurent; Andrade-Barosso, Guillermo; Simonin, Matthieu

    2015-04-01

    From the past decades the monitoring of civil engineering structure became a major field of research and development process in the domains of modelling and integrated instrumentation. This increasing of interest can be attributed in part to the need of controlling the aging of such structures and on the other hand to the need to optimize maintenance costs. From this standpoint the project Cloud2SM (Cloud architecture design for Structural Monitoring with in-line Sensors and Models tasking), has been launched to develop a robust information system able to assess the long term monitoring of civil engineering structures as well as interfacing various sensors and data. The specificity of such architecture is to be based on the notion of data processing through physical or statistical models. Thus the data processing, whether material or mathematical, can be seen here as a resource of the main architecture. The project can be divided in various items: -The sensors and their measurement process: Those items provide data to the main architecture and can embed storage or computational resources. Dependent of onboard capacity and the amount of data generated it can be distinguished heavy and light sensors. - The storage resources: Based on the cloud concept this resource can store at least two types of data, raw data and processed ones. - The computational resources: This item includes embedded "pseudo real time" resources as the dedicated computer cluster or computational resources. - The models: Used for the conversion of raw data to meaningful data. Those types of resources inform the system of their needs they can be seen as independents blocks of the system. - The user interface: This item can be divided in various HMI to assess maintaining operation on the sensors or pop-up some information to the user. - The demonstrators: The structures themselves. This project follows previous research works initiated in the European project ISTIMES [1]. It includes the infrared

  18. Experimental MR imaging with Gd-DOTA: Preliminary results

    International Nuclear Information System (INIS)

    Schouman-Claeys, E.; Kien, P.; Caille, J.M.; Bonnemain, B.; Frija, G.

    1986-01-01

    To evaluate the paramagnetic properties of a new gadolinium chelate, Gd-DOTA, in vitro and in vivo MR imaging was performed with a 0.5-T supraconductive magnet. The in vitro study consisted in measuring the MR signal obtained with various concentrations of Gd-DOTA and Gd-DTPA in different solutions. Potentialization of the paramagnetic properties of both DOTA and DTPA can be achieved by deuterium, glycerol, and protein solutions. The in vivo study was performed in rabbits with various experimental lesions. Enhancement of anatomic details was obtained with both Gd-DOTA and Gd-DTPA. There was no significant difference between Gd-DOTA and Gd-DTPA, both for in vitro and in vivo experiments. Gd-DOTA appears to be a potential paramagnetic agent for MR imaging

  19. Electrochemical investigation of the redox couple Sm(III)/Sm(II) on a tungsten electrode in molten LiF-CaF2-SmF3

    International Nuclear Information System (INIS)

    Korenko, M.; Kubikova, B.; Stulov, Y.V.; Kuznetsov, S.A.; Ambrova, M.

    2014-01-01

    This article is focused on the electrochemical investigation (cyclic voltammetry and related studies) of the redox couple Sm(III)/Sm(II) in an eutectic LiF-CaF 2 melt containing SmF 3 . The first step of reduction for Sm(III) ions involving one electron exchange in soluble/soluble Sm(III)/Sm(II) system was found on a tungsten electrode. The study of the Sm(II)/Sm(0) electrode reaction was not feasible, due to insufficient electrochemical stability of LiF-CaF 2 . The first step was found reversible at temperatures 1,075 and 1,125 K up to polarization rate 1 V/s and at temperature 1,175 K the process was reversible at all sweep rates applied in this study. The diffusion coefficients (D) of Sm(II) and Sm(III) ions were determined by cyclic voltammetry, showing that D decreases when oxidation state increase, while the activation energy of diffusion (E a ) increases. The standard rate constants of charge transfer (k s) were calculated for the redox couple Sm(III)/Sm(II) at 1,075 and 1,125 K based on the data of cyclic voltammetry. (author)

  20. Highly luminescent Eu{sup 3+}-doped benzenetricarboxylate based materials

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ivan G.N. [Departamento de Química Fundamental, Instituto de Química da Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-900, SP (Brazil); Mustafa, Danilo, E-mail: dmustafa@iq.usp.br [Departamento de Química Fundamental, Instituto de Química da Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-900, SP (Brazil); Andreoli, Bruno [Departamento de Química Fundamental, Instituto de Química da Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-900, SP (Brazil); Felinto, Maria C.F.C. [Centro de Química do Meio Ambiente, Instituto de Pesquisas Energéticas e Nucleares, Av. Prof. Lineu Prestes 2242, São Paulo 05508-000, SP (Brazil); Malta, Oscar L. [Departamento de Química Fundamental, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego, 1235, Recife 50670-90, PE (Brazil); Brito, Hermi F., E-mail: hefbrito@iq.usp.br [Departamento de Química Fundamental, Instituto de Química da Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-900, SP (Brazil)

    2016-02-15

    [RE(TMA)] anhydrous complexes (RE{sup 3+}: Y, Gd and Lu) present high red emission intensity with a quantum efficiency (~45%) for the [Y(TMA):Eu{sup 3+}] complexes, due to the absence of non-radioactive decay pathways mediated by water molecules. The complexes were prepared in mild conditions. All the compounds are crystalline and thermostable up to 460 °C. Phosphorescence data of the complexes with Y, Gd and Lu show that the T{sub 1} state of the TMA{sup 3−} anion has energy higher than the {sup 5}D{sub 0} emitting level of the Eu{sup 3+} ion, indicating that the ligand can act as an intramolecular energy sensitizer. The photoluminescence properties of the doped materials were studied based on the excitation and emission spectra and luminescence decay curves. The experimental intensity parameters (Ω{sub λ}), lifetimes (τ), radiative (A{sub rad}) and non-radiative (A{sub nrad}) decay rates were determined and discussed. - Highlights: • Highly luminescent Europium doped anhydrous complexes. • Efficient monochromatic red light conversion molecular devices (LCMDs). • High emission quantum efficiencies.

  1. GdNCT of spontaneous canine melanoma

    International Nuclear Information System (INIS)

    Mitin, V.N.; Kulakov, V.N.; Khokhlov, V.F.

    2006-01-01

    The effectiveness of GdNCT has been studied in dogs with spontaneous melanoma of the mucousmembrane of the oral cavity patients on the NCT base at the IRT MEPhI reactor. The control group with melanomas was treated with neutrons. Fourteen canine patients were selected in the Clinic of Experimental Therapy affiliated with the RCRC RAMS. The calculation of doses has shown that the total dose of energy release depending on Gd concentration in the target can be several times higher than the dose produced by the reactor neutron beam. The calculations were carried out using the diffusion pharmacokinetic model. The gadolinium drug dipentast was administered intratumorally immediately prior to irradiation. The tumor size was estimated by measuring it in three projections. The tumor was irradiated for 60-90 minutes with a thermal neutron flux of 0.7x10 9 n/cm 2 s. The dose on tumor was 80-120 Gy, on surrounding tissues - 12-15 Gy. The treatment plan included immunotherapy with Roncoleikin in a dose of (15-10)x10 3 IE/kg. The results of GdNCT are still under observation. The results conform to those obtained by us earlier in cell cultures and inoculated experimental tumors. GdNCT is also effective in combination with immunotherapy. (author)

  2. Theoretical Magnon Dispersion Curves for Gd

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker; Harmon, B. N.; Freeman, A. J.

    1975-01-01

    The magnon dispersion curve of Gd metal has been determined from first principles by use of augmented-plane-wave energy bands and wave functions. The exchange matrix elements I(k⃗, k⃗′) between the 4f electrons and the conduction electrons from the first six energy bands were calculated under...

  3. Magnetic short range order in Gd

    International Nuclear Information System (INIS)

    Child, H.R.

    1976-01-01

    Quasielastic neutron scattering has been used to investigate magnetic short range order in Gd for 80 0 K 0 K. Short range order exists throughout this range from well below T/sub C/ = 291 0 K to well above it and can be reasonably well described by an anisotropic Orstein-Zernike form for chi

  4. Gd-substituted Bi-2223 superconductor

    Indian Academy of Sciences (India)

    The effects of gadolinium doping at calcium site on the normal and super- conducting properties of Bi-2223 system were ... quantities of the metal oxides and the carbonates were taken and thoroughly mixed. The calcination of the mixture after .... Therefore, Gd has higher solubility in (BiPb)-2223 as compared to Pr, and is, ...

  5. Study of the nuclear structure of {sup 155}Eu; Estudo da estrutura nuclear do {sup 155}Eu

    Energy Technology Data Exchange (ETDEWEB)

    Genezini, Frederico Antonio

    2004-07-01

    The {sup 155}Eu nuclide was investigated by the directional angular correlation technique following the {beta} decay of {sup 155}Sm. The angular correlation measurements were carried out using a setup with 4 Ge detectors and a multi parametric data acquisition system. To perform the data analysis a new methodology was developed . The multipole mixing ratios of twenty sixty {gamma}- transitions were determined. Seven of them agreed with the results of earlier angular correlation studies and nineteen obtained for the first time confirmed the multipolarity suggested in earlier electron capture studies. Besides, the spin of the level at 1106.83 keV as well as the parity of the level at 1301.41 keV have also been suggested. The nuclear structure of {sup 155}Eu was discussed successfully in terms of the single particle model using a deformed Woods-Saxon potential plus residual pairing interaction permitting the description of the rotational quasi-proton band heads. (author)

  6. Conceptual Design Plan SM-43 Replacement Project

    Energy Technology Data Exchange (ETDEWEB)

    University of California, Los Alamos National Laboratory, SCC Project Office

    2000-11-01

    The Los Alamos National Laboratory Conceptual Design Plan for the SM-43 Replacement Project outlines plans for replacing the SM-43 Administration Building. Topics include the reasons that replacement is considered a necessity; the roles of the various project sponsors; and descriptions of the proposed site and facilities. Also covered in this proposal is preliminary information on the project schedule, cost estimates, acquisition strategy, risk assessment, NEPA strategy, safety strategy, and safeguards and security. Spreadsheets provide further detail on space requirements, project schedules, and cost estimates.

  7. EU Food Health Law

    DEFF Research Database (Denmark)

    Edinger, Wieke Willemijn Huizing

    and rational dietary choices on the basis of the food information provided on food labels or generally available in society. In recent years, the EU legislative has shown increased commitment to further empower consumers in pace with the advancement of modern manufacturing and advertising techniques......This thesis shows that the distinction between food safety and non-safety issues in Regulation (EC) No 178/2002, the General Food Law (GFL), results in a grey area of regulation. This grey area comprises foods that do not pose a food safety risk in a legal sense, but that could pose a threat...... to human health because of other factors, such as their nutritional composition. The growing prevalence of obesity and non-communicable diseases are examples of contemporary health challenges that are difficult to fit into the rather narrow concept of food safety risks in the GFL. The conclusion is that EU...

  8. EU og Latinamerika

    DEFF Research Database (Denmark)

    Agustin, Oscar Garcia

    2008-01-01

    I juni blev EU’s medlemslande enige om et direktiv angående hjemsendelse. Direktivet er en del af EU’s strategi om at udvikle en fælles ramme mod den såkaldte illegale immigration. Det tog ikke lang til, før reaktionen kom, og den kom rigtig stærkt fra Latinamerika, blandt andet gennem et åbent...... brev fra den bolivianske præsident, Evo Morales, stilet til EU. En måned før vedtagelsen af direktivet var de latinamerikanske lande blevet enige om at satse på en fælles politik med EU, der skulle bygge på et princip om fælles ansvar og en helhedstilgang til international migration med inddragelse af...

  9. Direct measurement of the magnetocaloric effect of microstructured Gd eutectic compounds using a new fast automatic device

    Science.gov (United States)

    Canepa, Fabio; Cirafici, Salvino; Napoletano, Myrta; Ciccarelli, Carlo; Belfortini, Claudio

    2005-01-01

    A newly designed experimental device for direct measurement of the magnetocaloric effect has been assembled and tested. Details about calibration and preliminary measurements performed on Gd as a standard reference material are reported together with results concerning the magnetocaloric effect of three different Gd eutectic compositions (Gd-Gd 7Pd 3, Gd-GdZn, Gd-GdCd).

  10. 'EU divertor celebration day'

    International Nuclear Information System (INIS)

    Merola, M.

    2002-01-01

    The meeting 'EU divertor celebration day' organized on 16 January 2002 at Plansee AG, Reutte, Austria was held on the occasion of the completion of manufacturing activities of a complete set of near full-scale prototypes of divertor components including the vertical target, the dome liner and the cassette body. About 30 participants attended the meeting including Dr. Robert Aymar, ITER Director, representatives from EFDA, CEA, ENEA, IPP and others

  11. EU COMPARISON OF VAT

    Directory of Open Access Journals (Sweden)

    MARIA ZENOVIA GRIGORE

    2012-05-01

    Full Text Available VAT is one of the newest tools of the global economy and is widely adopted in most of the countries. For EU Member States is required not only the existence of VAT, but also that its main characteristics to be uniformly implemented. This should facilitate intra-Community transactions, but in practice does not as there are many local variations which can lead to costly errors and penalties. The objective of this paper is to collate data about the main characteristics of VAT in EU Member States and to highlight the key differences between them. This survey shows that there continue to be opportunities and risks for businesses trading cross border, as a result of differences in application of Community legislation on VAT. This led to the necessity of VAT reform. On this basis, the Commission adopted on the end of the last year a Communication on the future of VAT. This sets out the fundamental characteristics that must underlie the new VAT regime, and priority actions needed to create a simpler, more efficient and more robust VAT system in the EU.

  12. Calculation of the band structure of GdCo2, GdRh2 e GdIr2 by the APW method

    International Nuclear Information System (INIS)

    Carvalho, J.A.B. de.

    1974-03-01

    The band structure of GdCo 2 , GdRh 2 , GdIr 2 has been calculated by the APW method. A histogram of the density of states is presented for each compound. The bands are transition-metal-like, with s-d hybridization near the Fermi level. The 5d character near the Fermi level increases as one goes from Co to Ir

  13. Irradiation response of radio-frequency sputtered Al/Gd2O3/p-Si MOS capacitors

    Science.gov (United States)

    Kahraman, A.; Yilmaz, E.

    2017-10-01

    The usage of the Gadolinium oxide (Gd2O3) as sensitive region in the MOS (Metal-Oxide-Semiconductor)-based dosimeters was investigated in the presented study. The Gd2O3 films grown on p-type Si (100) by RF magnetron sputtering were annealed at 800 °C under N2 ambient. The back and front metal contacts were establishes to produce MOS capacitors. The fabricated Gd2O3 MOS capacitors were irradiated in the dose range 0.5-50 Gy by 60Co gamma source. The performed Capacitance-Voltage (C-V) curves of the Gd2O3 MOS capacitors shifted to right side relative to pre-irradiation one. While continuous increments in the oxide trapped charges with increasing in gamma dose were observed, interface trapped charges fluctuated in the studied dose range. However, the variation of the interface trapped charge densities was found in the order of 1011 cm-2 and no significant variation was observed with applied dose. These results confirm that a significant deterioration does not occur in the capacitance during the irradiation. The higher oxide trapped charges compared to interface trapped charges showed that these traps were more responsible for the shift of the C-V curves. The sensitivity and percentage fading after 105 min of the Gd2O3 MOS capacitor were found as 39.7±1.4 mV/Gy and 14.5%, respectively. The devices sensitivity was found to be higher than that of capacitors composed of Er2O3, Sm2O3, La2O3, Al2O3, and SiO2, but, the high fading values is seen as a major problem for these capacitors. Finally, the barrier height was investigated with gamma exposure and the results showed that its value increased with increasing in radiation dose due to possible presence of the acceptor-like interface states.

  14. Luminescence properties of different Eu sites in LiMgPO4:Eu2+, Eu3+

    International Nuclear Information System (INIS)

    Baran, A; Mahlik, S; Grinberg, M; Cai, P; Kim, S I; Seo, H J

    2014-01-01

    The effect of temperature on the luminescence properties of LiMgPO 4 doped with Eu 3+ and Eu 2+ are presented. Depending on the excitation wavelength, luminescence spectra consist of two distinct broad emission bands peaking at 380 nm and 490 nm related to 4f 6 5d 1  → 4f 7 ( 8 S 7/2 ) luminescence of Eu 2+ and to europium-trapped exciton, respectively, and/or several sharp lines between the 580 nm and 710 nm region, ascribed to the 5 D 0  →  7 F J (J = 0, 1, 2, 3 and 4) transitions in Eu 3+ . To explain all the features of the Eu 2+ and Eu 3+ luminescence we discussed the existence of two different Eu sites substituting for Li + , with short and long distance compensation. The evident effect of increasing the intensity of the Eu 2+ luminescence with increasing temperature was observed. It was considered that the charge compensation mechanism for Eu 3+ and Li + as well as Eu 2+ replacing Li + in the LiMgPO 4 is a long distance compensation that allows for the existence of some of the europium ions either as Eu 3+ at low temperature or as Eu 2+ at high temperature. We concluded that Eu 2+ in the Li + site with long distance compensation yields only 4f 6 5d 1  → 4f 7 luminescence, whereas Eu 2+ in the Li + site with short distance compensation yields 4f 6 5d 1  → 4f 7 luminescence and europium-trapped exciton emission. (paper)

  15. Structural, magnetic and magnetocaloric properties of EuMnO3 perovskite manganite: A comprehensive MCE study

    Science.gov (United States)

    Phebe Kokila, I.; Kanagaraj, M.; Sathish Kumar, P.; Peter, Sebastian C.; Sekar, C.; Annal Therese, Helen

    2018-02-01

    Pervoskite manganite EuMnO3 synthesized by solid-state route was studied for their structural and magnetocaloric properties. EuMnO3 formed a single phase compound in orthorhombic crystal structure with a space group of Pbnm. The zero field cooling and field cooling magnetic responses exhibit an optimal Neel temperature (TN) of 57 K. A stronger magnetic coupling between the EuMnO3 particles are observed by a delay in reaching TN. The magnetocaloric effect analyzed extensively from the negative entropy (‑ΔSm) change of 15.23 JKg‑1K‑1 for EuMnO3, exhibited a Relative Cooling Power (RCP) of ∼211 JKg‑1 at 1.2 T proposing EuMnO3 as a potential magnetic refrigerant.

  16. Calorimetric investigation on the Pb-Sm and Sn-Sm alloys

    International Nuclear Information System (INIS)

    Berrada, A.-E.-A.; Claire, Y.; Chafik el Idrissi, M.; Castanet, R.

    1997-01-01

    The integral enthalpy of formation of the Sm-Pb and Sm-Sn melts at 1203 K, h f , was determined by direct reaction calorimetry (drop method) in the Pb and Sn rich sides with the help of a high-temperature Tian-Calvet calorimeter. The results can be fitted respectively with reference to the mole fraction of samarium, x, as follows: f /kJmol -1 =x(1-x)(-109.8 -372.0.7x) with 0 Sm f /kJmol -1 =x(1- x)(-277.0+105.4x) with 0 Sm -1 respectively. Such negative values suggest the existence of a strong short-range order in the liquid state. The stoichiometry and the thermal stability of these associations needs additional thermodynamic determinations concerning mainly the free enthalpy of formation. It will be determined by Knudsen-effusion combined with mass spetrometry in a further work. (orig.)

  17. N -Sm A -Sm C phase transitions probed by a pair of elastically bound colloids

    Science.gov (United States)

    M, Muhammed Rasi; Zuhail, K. P.; Roy, Arun; Dhara, Surajit

    2018-03-01

    The competing effect of surface anchoring of dispersed microparticles and elasticity of nematic and cholesteric liquid crystals has been shown to stabilize a variety of topological defects. Here we study a pair of colloidal microparticles with homeotropic and planar surface anchoring across N -Sm A -Sm C phase transitions. We show that below the Sm A -Sm C phase transition the temperature dependence of interparticle separation (D ) of colloids with homeotropic anchoring shows a power-law behavior; D ˜(1-T /TA C) α , with an exponent α ≈0.5 . For colloids with planar surface anchoring the angle between the joining line of the centers of the two colloids and the far field director shows characteristic variation elucidating the phase transitions.

  18. Optical thermometry based on green upconversion emission in Er3+/Yb3+ codoped BaGdF5 glass ceramics

    Science.gov (United States)

    Wu, Ting; Zhao, Shilong; Lei, Ruoshan; Huang, Lihui; Xu, Shiqing

    2018-02-01

    Er3+/Yb3+ codoped BaGdF5 glass ceramics have been prepared and used to develop a portable all-fiber temperature sensor based on fluorescence intensity ratio technique. XRD and TEM results affirm the generation of BaGdF5 nanocrystals in the borosilicate glass. Eu3+ ions are used as spectral probe to investigate external environment around rare earth (RE) ions. Intense green upconversion emissions from Er3+ ions are detected in the BaGdF5 glass ceramics and their intensity are enhanced about three orders of magnitude after heat treatment, which is attributed to the enrichment of RE ions in the BaGdF5 phase. Based on green upconversion emission from Er3+ ions, the temperature sensing property of the portable all-fiber temperature sensor is studied. The maximum absolute sensitivity is 15.5 × 10‑4 K‑1 at 567 K and the relative sensitivity is 1.28% K‑1 at 298 K, respectively.

  19. Moessbauer and channeling experiments on TeSi and SmSi

    International Nuclear Information System (INIS)

    Kemerink, G.J.; Boerma, D.O.; Waard, H. de; Wit, J.C. de; Drentje, S.A.

    1980-01-01

    Considerable effort is made to obtain an insight in the structural and electronic properties of ion implanted elemental semiconductors. This research is strongly stimulated by the many applications of semi-conductor devices. We report here on Moessbauer studies of 129 TeSi and 153 SmSi, using the 27.8 keV transition in 129 I and the 103.2 keV transition in 153 Eu, respectively, and on channeling experiments on 128 TeSi and 152 SmSi with a 2 MeV α-beam from the Groningen Van de Graaff generator. In the Moessbauer experiments we used Cu 129 I and EuF 3 .1/2H 2 O as absorber materials. Source and absorber were held at 4.2 K. The implantations were generally done at room temperature with an implantation energy of 100-115 keV. For the Moessbauer and channeling measurements we applied similar Si single crystals and the same implantation and annealing conditions. Crystals with low doses could only be investigated with the Moessbauer effect

  20. CW laser properties of Nd:GdYAG, Nd:LuYAG, and Nd:GdLuAG mixed crystals

    Science.gov (United States)

    Di, J. Q.; Xu, X. D.; Li, D. Z.; Zhou, D. H.; Wu, F.; Zhao, Z. W.; Xu, J.; Tang, D. Y.

    2011-10-01

    Three mixed crystals, Nd:GdYAG, Nd:LuYAG, and Nd:GdLuAG, were grown by Czochralski method. We report the continuous-wave (CW) Nd:GdYAG, Nd:LuYAG, and Nd:GdLuAG laser operation under laser diode pumping. The maximum output powers are 4.11, 5.31, and 7.47 W, with slope efficiency of 73.0, 55.3, and 57.1%, respectively. With replacing Lu3+ or Y3+ ions with large Gd3+ ions, the pump efficiency increases.

  1. The crystallization of Al-Sm amorphous alloys

    International Nuclear Information System (INIS)

    Rizzi, P.; Baricco, M.; Battezzati, L.; Schumacher, P.; Greer, A.L.

    1995-01-01

    Amorphous alloys with composition Al 100-x Sm x (8 ≤ x ≤ 14) have been prepared by melt spinning in controlled atmosphere. The quenching conditions significantly influence the microstructure of as-quenched samples and their crystallization mechanisms. The crystallization was followed by means of DSC, XRD, TEM and SEM. Different mechanisms are observed as a function of composition. For low Sm content (Al 92 Sm 8 ), a primary crystallization occurs at about 180 C, with the formation of Al nanocrystals with a grain size of about 15 nm. A polymorphic crystallization is found in Al 90 Sm 10 , with the formation of a metastable intermetallic phase at about 220 C. For higher Sm content (Al 88 Sm 12 and Al 86 Sm 14 ), a eutectic crystallization at about 230 C gives a mixture of stable (Al and Al 11 Sm 3 ) and metastable phases. (orig.)

  2. الفائق التوصيل الكهربائي SmBa2Cu3O7-δ على خواص المركب Eu و Sn و Zn - تأثير التعويض الجزئي للعناصر

    Directory of Open Access Journals (Sweden)

    أحمد محمد كاظم

    2000-06-01

    Full Text Available تمت دراسة تأثير التعويض الجزئي لعناصرEu  و Sr و Zn في كل من العناصرSm و Ba و Cu  على الترتيب على خواص المركب SmBa2Cu3O7-d ذي التوصيلية الكهربائيةالفائقة في درجات الحرارة العالية. أظهرت النتائج أن التعويض الجزئي لعنصر اليوروبيوم Eu في عنصر السماريوم Sm  أبقى المركب محافظا على هيئة تركيب المعيني القائم بينما أدى إلى زيادة درجة الحرارة الحرجة من K 88 الى 107 K عندما تزداد قيمة التعويض من 0 الى 0.2. أما التعويض الجزئي لعنصر السترونتيوم Sr في عنصر الباريومBa بنسب  0 و 0.1 و 0.2 و 0.3 و 0.4  و 0.5 قد اظهر تشوها في التركيب البلوري و انخفاض في قيم حجم وحدة الخلية و درجة الحرارة الحرجة. أما التعويض الجزئي لعنصر الخارصين Zn في عنصر النحاسCu  بنسبة 0.3 قد أدى إلى تشوه كبير جدا في التركيب البلوري و فقدان لخاصية التوصيل الكهربائي الفائق.

  3. Shape tunable synthesis of Eu- and Sm-doped ZnO microstructures ...

    Indian Academy of Sciences (India)

    Velazquez J M, Baskaran S, Gaikwad A V, Ngo-Duc T T, He. X, Oye M M, Meyyappan M, Rout T K, Fu J Y and Banerjee. S 2013 ACS Appl. Mater. Interfaces 5 10650. 16. Sadollahkhani A, Kazeminezhad I, Lu J, Nur O, Hultman L and Willander M 2014 RSC Adv. 4 36940. 17. Kumar R, Anandan S, Hembram K and Rao T N ...

  4. Sm3+ and Eu3+ sorption in mixed phosphates of Zr

    International Nuclear Information System (INIS)

    Contreras R, A.

    2011-01-01

    The storage of high level radioactive waste in deep geological repositories is an issue of international research in countries with nuclear reactors. A major risk is the groundwater infiltration, which can cause degradation of the containers and leaching the radioactive waste through the different barriers. The study of materials for use as engineered barriers is fundamental, because if dissolution is present, the elements can be captured, ensuring that radioactive materials do not disperse off. The work is divided in four parts, the first describes the techniques developed for the synthesis of phosphates: NaZr 2 (PO 4 ) [NZP] and τ-Zr(Na 0.06 H 0.94 PO 4 ) 2 [TZP-Na], their chemical and morphological characterization, thermal stability and surface area. The obtained NZP shows a diffraction diagram similar to the Jcpds pattern, it has a surface area of 4.9±0.1 m 2 ·g -1 . There are not reports of diffraction patterns for TZP-Na, which has a surface area of 22.9±0.40 m 2 ·g -1 . The hydrogenphosphate obtained, τ-Zr(HPO 4 ) 2 , shows a diffraction diagram similar to that reported by Nor by. The second part presents the physicochemical characterization of the phosphates surface. The constants of formation of surface sites and their distribution were calculated using FITEQL 4.0. The sites surface density (d s ) were determined from potentiometric titration curves of phosphate, hydrogen phosphate and NaClO 4 0.5 M; d s were 3.2 sites nm -2 for NZP and 2.1 sites·nm -2 for TZP-Na. The values of curves formation constants for surface sites were, for NZP: K 1P-O =2, K 2P-O =-7, K 1Zr-O =6.11, K 1Zr-O =7.94, and for TZP-Na: K 1P-O =5.14, K 2P-O =-7.03, K 1Zr-O =2.60, K 1Zr-O =-9.85. The third part of the work reports the samarium and europium sorption curves on phosphate and on hydrogenphosphate at different ph values. The values of the curves were fed on FITEQL 4.0 program and NZP surface complexation constants were obtained. The results for the NZP show, for both lanthanides, a monodentate complex at the zirconium site and a bidentate complex on the phosphate site. The fourth part of the research reports on the stability of phosphate and hydrogenphosphate to gamma radiation, with doses of: 10, 30 and 50 MGy. The NZP irradiated at 50 MGy showed very slight changes in their morphology, which changed to hexagonal sheets to cubic form; heating the irradiated NZP regenerates the original morphology. The irradiated TZP-Na showed changes in its crystalline structure but without becoming amorphous, however it maintained its chemical and morphology structure. In conclusion, both phosphates, NaZr 2 (PO 4 ) and τ-Zr(Na 0.06 H 0.94 PO 4 ) 2 , may be considered for sorption of lanthanides in the barriers, even though the NZP is more resistant to radiation. (Author)

  5. Shape tunable synthesis of Eu- and Sm-doped ZnO microstructures ...

    Indian Academy of Sciences (India)

    SD), double distilled water (DD), degreased with acetone, ultra-sonically cleaned by DD and finally dried in air. 2.2 Synthesis of ZnO microdisks. The procedure reported by Self et al25 was followed. In brief,. 0.356g of zinc nitrate hexahydrate was ...

  6. Magnetic behavior of light rare earth ions in (Nd,Eu,Gd)-123 superconductors

    Czech Academy of Sciences Publication Activity Database

    Jirsa, Miloš; Rameš, Michal; Marcenat, C.; Wolf, T.

    2013-01-01

    Roč. 26, č. 4 (2013), s. 901-905 ISSN 1557-1939 R&D Projects: GA MŠk(CZ) ME10069 Institutional support: RVO:68378271 Keywords : high- T c superconductors * cuprates * thermodynamic properties * LRE-123 * paramagnetic ions Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.930, year: 2013

  7. Eu, Gd-Codoped Yttria Nanoprobes for Optical and T1-Weighted Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Timur Sh Atabaev

    2017-02-01

    Full Text Available Nanoprobes with multimodal functionality have attracted significant interest recently because of their potential applications in nanomedicine. This paper reports the successful development of lanthanide-doped Y2O3 nanoprobes for potential applications in optical and magnetic resonance (MR imaging. The morphology, structural, and optical properties of these nanoprobes were characterized by transmission electron microscope (TEM, field emission scanning electron microscope (FESEM, X-ray diffraction (XRD, energy-dispersive X-ray (EDX, and photoluminescence (PL. The cytotoxicity test showed that the prepared lanthanide-doped Y2O3 nanoprobes have good biocompatibility. The obvious contrast enhancement in the T1-weighted MR images suggested that these nanoprobes can be used as a positive contrast agent in MRI. In addition, the clear fluorescence images of the L-929 cells incubated with the nanoprobes highlight their potential for optical imaging. Overall, these results suggest that prepared lanthanide-doped Y2O3 nanoprobes can be used for simultaneous optical and MR imaging.

  8. The EU agencies’ role in policy diffusion beyond the EU

    DEFF Research Database (Denmark)

    Chatzopoulou, Sevasti

    The extensive literature on the EU agencies has mainly focused on their role in the harmonisation and expansion of regulatory standards within the EU. This paper joins this literature and investigates the role of EU agencies in policy diffusion beyond the EU borders. To operationalise this......, the paper identifies and compares the organisation structural characteristics in three decentralised agencies, namely the European Environmental Agency (EEA), the European Medicine Agency (EMA), and the European Food Safety Authority (EFSA). These agencies share a common interest in the environment...

  9. Preparation and quality control of {sup 153}Sm radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Swasono, R. Tamat; Widyastuti, W.; Purwadi, B.; Laksmi, I. [Radioisotope Production Center - BATAN, Jakarta (Indonesia)

    1998-10-01

    The paper summarizes the preparation and quality control of {sup 153}Sm-EDTMP and three {sup 153}Sm-radiosynovectomy agents. Natural and enriched Sm{sub 2}O{sub 3} (98.7% {sup 152}Sm) irradiated in RSG-GAS 30 MW reactor yielded pure and high specific activity {sup 153}Sm. Labeling of EDTMP with {sup 153}Sm was carried out by mixing {sup 153}SmCl{sub 3} solution of pH 4.0 to an EDTMP solution at room temperature then pH adjustment to 8. The {sup 153}Sm-EDTMP complex was separated from the free {sup 153}Sm{sup +3} on a Chelex 100 column. Radiochemical purity was determined by thin layer chromatography using Cellulose sheets and pyridine: ethanol: water (1: 2: 4) mixture as solvent. The {sup 153}Sm-EDTMP has been shown to be stable for two weeks. Three particulate preparations of {sup 153}Sm used for the irradiation of chronic synovitis have been studied. They are hydroxyapatite particles, human serum albumin microspheres and ferric hydroxide macroaggregates. The {sup 153}Sm-ferric hydroxide macroaggregates were prepared in a single step by coprecipitation of {sup 153}Sm in the formation of Fe(OH){sub 3}. Preparation of {sup 153}Sm-labelled hydroxyapatite particles and {sup 153}Sm-labelled albumin microspheres were carried out by {sup 153}Sm labelling of previously prepared particles. Radiolabelling efficiency were greater than 95% for hydroxyapatite particles and macroaggregates and was lower than 20% for albumin microspheres. The particle sizes were inspected using an optical microscope with a haemocytometer and micrometric ocular. (author)

  10. Gd-substituted Bi-2223 superconductor

    Indian Academy of Sciences (India)

    resistivity with a view to study metal-to-insulator transition, (2) the XRD patterns of the specimens with a view to study the .... values [4] of the transition temperatures for Gd-substituted (BiPb)-2212 specimens. The specimens of Batches I and II with x > 0.4 .... (retd) P N Dheer and Dr R G Sharma. 540. Pramana – J. Phys., Vol.

  11. GD SDR Automatic Gain Control Characterization Testing

    Science.gov (United States)

    Nappier, Jennifer M.; Briones, Janette C.

    2013-01-01

    The General Dynamics (GD) S-Band software defined radio (SDR) in the Space Communications and Navigation (SCAN) Testbed on the International Space Station (ISS) will provide experimenters an opportunity to develop and demonstrate experimental waveforms in space. The GD SDR platform and initial waveform were characterized on the ground before launch and the data will be compared to the data that will be collected during on-orbit operations. A desired function of the SDR is to estimate the received signal to noise ratio (SNR), which would enable experimenters to better determine on-orbit link conditions. The GD SDR does not have an SNR estimator, but it does have an analog and a digital automatic gain control (AGC). The AGCs can be used to estimate the SDR input power which can be converted into a SNR. Tests were conducted to characterize the AGC response to changes in SDR input power and temperature. This purpose of this paper is to describe the tests that were conducted, discuss the results showi ng how the AGCs relate to the SDR input power, and provide recommendations for AGC testing and characterization.

  12. Arterial injury promotes medial chondrogenesis in Sm22 knockout mice.

    Science.gov (United States)

    Shen, Jianbin; Yang, Maozhou; Jiang, Hong; Ju, Donghong; Zheng, Jian-Pu; Xu, Zhonghui; Liao, Tang-Dong; Li, Li

    2011-04-01

    Expression of SM22 (also known as SM22alpha and transgelin), a vascular smooth muscle cells (VSMCs) marker, is down-regulated in arterial diseases involving medial osteochondrogenesis. We investigated the effect of SM22 deficiency in a mouse artery injury model to determine the role of SM22 in arterial chondrogenesis. Sm22 knockout (Sm22(-/-)) mice developed prominent medial chondrogenesis 2 weeks after carotid denudation as evidenced by the enhanced expression of chondrogenic markers including type II collagen, aggrecan, osteopontin, bone morphogenetic protein 2, and SRY-box containing gene 9 (SOX9). This was concomitant with suppression of VSMC key transcription factor myocardin and of VSMC markers such as SM α-actin and myosin heavy chain. The conversion tendency from myogenesis to chondrogenesis was also observed in primary Sm22(-/-) VSMCs and in a VSMC line after Sm22 knockdown: SM22 deficiency altered VSMC morphology with compromised stress fibre formation and increased actin dynamics. Meanwhile, the expression level of Sox9 mRNA was up-regulated while the mRNA levels of myocardin and VSMC markers were down-regulated, indicating a pro-chondrogenic transcriptional switch in SM22-deficient VSMCs. Furthermore, the increased expression of SOX9 was mediated by enhanced reactive oxygen species production and nuclear factor-κB pathway activation. These findings suggest that disruption of SM22 alters the actin cytoskeleton and promotes chondrogenic conversion of VSMCs.

  13. Sm-Nd isotope province of Crust of Central Asia

    International Nuclear Information System (INIS)

    Kovalenko, V.I.; Yarmolyhk, V.V.; Kozakov, I.K.; Kovach, V.P.; Kotov, V.B.; Sal'nikova, E.B.

    1996-01-01

    Results on the Sm-Nd isotope systematic studies of granitoid rocks in the Central Asia are presented. The Sm-Nd isotope provinces, characterized by various Sm-Nd model ages of intrusive granitoids, are separated. The Doriferian, Caledonian, and Hercynian provinces refer to the main ones. 7 refs., 1 fig

  14. Kampen om det sibiriske smør

    DEFF Research Database (Denmark)

    Larsen, Inge Marie

    2001-01-01

    Afhandlingen følger opbygningen af og udviklingen i den vestsibiriske smørsektor og den internationale handel med sibirisk smør. Hvordan gik det til, at Rusland blev verdens næststørste smøreksportør? Indfaldsvinkelen er lokal sibirisk, national russisk og global, idet danske og engelske firmaers...

  15. Thermal Behaviour of Sm0.5 R 0.5FeO3 (R = Pr, Nd) Probed by High-Resolution X-ray Synchrotron Powder Diffraction.

    Science.gov (United States)

    Pavlovska, Olena; Vasylechko, Leonid; Buryy, Oleh

    2016-12-01

    Mixed ferrites Sm0.5Pr0.5FeO3 and Sm0.5Nd0.5FeO3 with orthorhombic perovskite structure isotypic with GdFeO3 were synthesized by solid-state reaction technique in air at 1473 K. Structural parameters obtained at room temperature prove a formation of continuous solid solutions in the SmFeO3-PrFeO3 and SmFeO3-NdFeO3 pseudo-binary systems. Sm0.5Pr0.5FeO3 and Sm0.5Nd0.5FeO3 show strongly anisotropic nonlinear thermal expansion: thermal expansion in the b direction is twice lower than in the a and c directions. The average linear thermal expansion coefficients of Sm0.5Pr0.5FeO3 and Sm0.5Nd0.5FeO3 in the temperature range of 298-1173 K are in the limits of (9.0-11.1) × 10(-6) K(-1), which is close to the values reported for the parent RFeO3 compounds. Subtle anomalies in the lattice expansion of Sm0.5Pr0.5FeO3 and Sm0.5Nd0.5FeO3 detected at 650-750 K reflect magnetoelastic coupling at the magnetic ordering temperature T N.

  16. Synthesis and characterization of Gd-doped magnetite nanoparticles

    International Nuclear Information System (INIS)

    Zhang, Honghu; Malik, Vikash; Mallapragada, Surya; Akinc, Mufit

    2017-01-01

    Synthesis of magnetite nanoparticles has attracted increasing interest due to their importance in biomedical and technological applications. Tunable magnetic properties of magnetite nanoparticles to meet specific requirements will greatly expand the spectrum of applications. Tremendous efforts have been devoted to studying and controlling the size, shape and magnetic properties of magnetite nanoparticles. Here we investigate gadolinium (Gd) doping to influence the growth process as well as magnetic properties of magnetite nanocrystals via a simple co-precipitation method under mild conditions in aqueous media. Gd doping was found to affect the growth process leading to synthesis of controllable particle sizes under the conditions tested (0–10 at% Gd 3+ ). Typically, undoped and 5 at% Gd-doped magnetite nanoparticles were found to have crystal sizes of about 18 and 44 nm, respectively, supported by X-ray diffraction and transmission electron microscopy. Our results showed that Gd-doped nanoparticles retained the magnetite crystal structure, with Gd 3+ randomly incorporated in the crystal lattice, probably in the octahedral sites. The composition of 5 at% Gd-doped magnetite was Fe (3−x) Gd x O 4 (x=0.085±0.002), as determined by inductively coupled plasma mass spectrometry. 5 at% Gd-doped nanoparticles exhibited ferrimagnetic properties with small coercivity (~65 Oe) and slightly decreased magnetization at 260 K in contrast to the undoped, superparamagnetic magnetite nanoparticles. Templation by the bacterial biomineralization protein Mms6 did not appear to affect the growth of the Gd-doped magnetite particles synthesized by this method. - Highlights: • Gd-doped magnetite nanoparticles are synthesized via aqueous co-precipitation method under mild conditions. • Gd doping affects growth of magnetite nanoparticles leading to tunable particle size. • Gd-doped magnetite nanoparticles exhibit ferrimagnetic properties.

  17. Magnetocaloric properties and solid solution strengthening of Gd-C and Gd-Dy-C alloys

    International Nuclear Information System (INIS)

    Chen Yungui; Wu Jinping; Xiao Sufen; Zhang Tiebang; Tang Yongbai; Tu Mingjing

    2006-01-01

    In this paper, the near room temperature magnetic refrigerating solid solution alloys, Gd 1-x -C x (x ≤ 5 at.%) and Gd 0.98-x Dy x C 0.02 (x ≤ 20 at.%), were investigated together with a consideration of mechanical properties required by the container of the refrigerant material in a magnetic refrigerator. The results show that the micro-hardness of pure gadolinium metal can be much improved by adding carbon. The Curie temperature and adiabatic temperature changes of the Gd 1-x C x (x 0.98-x Dy x C 0.02 alloys can be tuned by adding dysprosium and their adiabatic temperature changes do not change much in a magnetic field change of 0-1 T

  18. SM-1420 computer conjugation with the ES-5017 magnetic tape storage device and the SM-6313 printer

    International Nuclear Information System (INIS)

    Zhurkin, V.V.; Safonov, A.A.; Troitskij, A.N.

    1987-01-01

    The flow sheets are given and the methods of the technical implementation of expansion units of SM 5002.4 controllers to connect NML ES-5017 and analogue-digital printer ATsPU SM-6818, respectively, to SM-1420 computer are described

  19. Evaluation of Gd and Gd159 as new approaches for cancer treatment

    International Nuclear Information System (INIS)

    Galvao, I.; Neves, M.J.

    2011-01-01

    Metal compounds have shown many biological activities and have been successfully used as anticancer agents such cisplatin. Actually gadolinium (Gd) complexed with a porphyrin Motexafin (MGd) has been investigated as redox-active compound for treatment of cancer. 1 59G d decays by beta emission with an energy of 970 keV and half-life of 18.59 hours. The de-excitation can be via gamma ray and internal conversion electron emission followed by auger electrons and x rays. Considering all of this 1 59G d could be a interesting radionuclide to be as a radio therapeutical agent. The aims of this works were to evaluate the cytotoxicity of Gd and 1 59G d on malignant brain tumors such as glioblastoma multiform, the most frequent brain tumors which has a very poor prognosis. For this purpose, it was used human glioblastoma cell lines T98 (mutant p53) and U87 (wild-type p53) to investigate the cytotoxicity of gadolinium on cell metabolism by MTT assay and also morphological changes, chromatin condensation by DAPI assay and ROS generation. Gadolinium was able to decrease cell viability, the cells presented morphological changes like round shapes and blebs formation after cell treatment with 5x10 -6 M of Gd. Nuclear changing and ROS generation occurred in a dose dependent way indicating the cytotoxic effect of Gd. Treatment with 1 59G d increased all of changes observed with treatment with Gd. These results state for an additive effect of metal toxicity and radioactivity inducing ROS generation as the main mechanism of anti tumoral action of 1 59G d. The results obtained indicated that the radioactive analogues of Gd have increased cytotoxic effects and gadolinium can be a metal of choice for development of new drugs for cancer treatment. (author)

  20. The mercury-richest europium amalgam Eu{sub 10}Hg{sub 55}

    Energy Technology Data Exchange (ETDEWEB)

    Tambornino, Frank; Hoch, Constantin [Department of Chemistry, Ludwig-Maximilians-Universitaet Muenchen (Germany)

    2015-03-15

    The mercury-richest europium amalgam Eu{sub 10}Hg{sub 55} was synthesized by isothermal electrocrystallization from a solution of EuI{sub 3}.8DMF in DMF on a reactive mercury cathode. The crystal structure shows remarkable complexity and polar metal-metal bonding. Closely related to the structures of mercury-rich amalgams A{sub 11-x}Hg{sub 55+x} (A = Na, Ca, Sr), it shows underoccupied Hg positions along [00z]. Eu{sub 10}Hg{sub 55} can be described as hettotype structure of the Gd{sub 14}Ag{sub 51} structure type. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. X(5 Symmetry to 152Sm

    Directory of Open Access Journals (Sweden)

    Eid S. A.

    2016-07-01

    Full Text Available The excited positive and negative parity states, potential energy surfaces, V ( ; , electromagnetic transition probabilities, B ( E 1, B ( E 2, electric monopole strength X ( E 0 = E 2 and staggering e ect, I = 1, were calculated successfully using the inter- acting boson approximation model IBA -1. The calculated values are compared to the available experimental data and show reasonable agreement. The energy ratios and contour plot of the potential energy surfaces show that 152 Sm is an X (5 candidate.

  2. Sm2Se3-PbSe system

    International Nuclear Information System (INIS)

    Shafagatova, G.G.; Nasibov, I.O.; Sultanov, T.I.; Rustamov, A.G.; Rustamov, P.G.

    1979-01-01

    The method of differential, X-ray phase microstructure analyses, and also microhardness and density measurements are used to study the system Sm 2 Se 3 -PbSe, and its state diagram has been constructed for the first time. It represents a quasi-binary cross section of the ternary system Sm-Pb-Se. It has been found that two new compounds, Sm 2 PbSe 4 and Sm 2 Pb 4 Se 7 , are formed in the system Sm 2 Se 3 -PbSe, of which the latter is peritectic. The region of PbSe-base α-solid solutions goes up to 6 mole%

  3. Ab initio study of the structural, electronic, elastic and magnetic properties of Cu2GdIn, Ag2GdIn and Au2GdIn

    International Nuclear Information System (INIS)

    Berri, Saadi; Maouche, Djamel; Zerarga, Fares; Medkour, Youcef

    2012-01-01

    We preformed first-principle calculations for the structural, electronic, elastic and magnetic properties of Cu 2 GdIn, Ag 2 GdIn and Au 2 GdIn using the full-potential linearized augmented plane wave (FP-LAPW) scheme within the generalized gradient approximation by Wu and Cohen (GGA-WC), GGA+U, the local spin density approximation (LSDA) and LSDA+U. The lattice parameters, the bulk modulus and its pressure derivative and the elastic constants were determined. Also, we present the band structures and the densities of states. The electronic structures of the ferromagnetic configuration for Heusler compounds (X 2 GdIn) have a metallic character. The magnetic moments were mostly contributed by the rare-earth Gd 4f ion.

  4. Eu(III) Complexes of Octadentate 1-Hydroxy-2-pyridinones: Stability and Improved Photophysical Performance

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Evan G.; D' Aleo, Anthony; Xu, Jide; Raymond, Kenneth N.

    2009-05-29

    The luminescence properties of lanthanoid ions can be dramatically enhanced by coupling them to antenna ligands that absorb light in the UV-visible and then efficiently transfer the energy to the lanthanoid centre. The synthesis and the complexation of Ln{sup III} cations (Ln = Eu, Gd) for a ligand based on four 1-hydroxy-2-pyridinone (1,2-HOPO) chelators appended to a ligand backbone derived by linking two L-lysine units (3LI-bis-LYS) is described. This octadentate Eu{sup III} complex ([Eu(3LI-bis-LYS-1,2-HOPO)]{sup -}) has been evaluated in terms of its thermodynamic stability, UV-visible absorption and luminescence properties. For this complex, the conditional stability constant (pM) is 19.9, which is an order of magnitude higher than diethylenetriaminepentacetic acid at pH = 7.4. This Eu{sup III} complex also shows an almost two-fold increase in its luminescence quantum yield in aqueous solution (pH = 7.4) when compared with other octadentate ligands. Hence, despite a slight decrease of the molar absorption coefficient, a much higher brightness is obtained for [Eu(3LI-bis-LYS-1,2-HOPO)]{sup -}. This overall improvement was achieved by saturating the coordination sphere of the Eu{sup III} cation, yielding an increased metal-centred efficiency by excluding solvent water molecules from the metal's inner sphere.

  5. Administrative sanctions in EU law

    NARCIS (Netherlands)

    de Moor-van Vugt, A.

    2012-01-01

    EU law has broadened the scope of administrative sanctioning by adding a variety of sanctions to the palette of sanctions in national law. Since the coming into force of the Charter, EU procedural standards are modelled on the ‘criminal charge’ case law of the ECtHR. These standards are discussed

  6. Trade microenterprises in EU economy

    Directory of Open Access Journals (Sweden)

    Zbigniew Gołaś

    2010-01-01

    Full Text Available The article shows the results of the analysis of positions of microenterprises in trade and repair in European Union (EU economy. The results show that microenterprises make up the most numerous group of economic subjects in EU. In terms of income generation, value added, labour productivity and financial efficiency the position of microenterprises in enterprises sector is conclusively the weakest.

  7. National Courts and EU Law

    DEFF Research Database (Denmark)

    rights in the area of freedom, security and justice. The analysis of each is enriched through diverse research methods such as case-law analysis, citation network analysis, interviews, surveys and statistics. With its new legal and empirical assessment covering the newest member states of the EU......This insightful and discerning book offers a fresh discourse on the functioning of national courts as decentralised EU courts and a new thematic for revising some older understandings of how national judges apply EU law. Organised into three key sections, the interdisciplinary chapters combine...... approaches and theories originating from law, political science, sociology and economics. The first section addresses issues relating to judicial dialogue and EU legal mandates, the second looks at the topic of EU law in national courts and the third considers national courts’ roles in protecting fundamental...

  8. 31 CFR 585.413 - Imports of goods originating in the FRY (S&M), and purchases of goods from the FRY (S&M).

    Science.gov (United States)

    2010-07-01

    ... FRY (S&M), and purchases of goods from the FRY (S&M). 585.413 Section 585.413 Money and Finance... of goods originating in the FRY (S&M), and purchases of goods from the FRY (S&M). Goods originating in the FRY (S&M) imported into the United States pursuant to an authorization or license are not...

  9. Investigation of the interactions of the components in the Sm-Pd-Ge system

    International Nuclear Information System (INIS)

    Kurenbaeva, J.M.; Seropegin, Yu.D.; Nikiforov, V.N.

    1998-01-01

    A variety of physicochemical analysis techniques have been employed in constructing the isothermal section of the phase diagram of the Sm-Pd-Ge system at 870 K. Several new ternary compounds have been found: Sm 3 Pd 20-18.5 Ge 6-7.5 , SmPd 2.50-1.75 Ge 1.50-2.25 , Sm 2 Pd 3 Ge 5 , Sm 2 PdGe 6 , SmPd 3 Ge, SmPd 2 Ge, SmPdGe 2 , SmPdGe, SmPd 0.8-0.5 Ge 1.2-1.5 , and Sm 2 PdGe. The temperature dependencies of the specific resistance were investigated for Sm 20 Pd 35 Ge 45 , Sm 20 Pd 40 Ge 40 , Sm 20 Pd 45 Ge 35 , and Sm 3 Pd 20 Ge 6 . (orig.)

  10. Coercivity Recovery Effect of Sm-Fe-Cu-Al Alloy on Sm2Fe17N3 Magnet

    Science.gov (United States)

    Otogawa, Kohei; Asahi, Toru; Jinno, Miho; Yamaguchi, Wataru; Takagi, Kenta; Kwon, Hansang

    2018-03-01

    The potential of a Sm-Fe-Cu-Al binder for improvement of the magnetic properties of Sm2Fe17N3 was examined. Transmission electron microscope (TEM) observation of a Sm-Fe-Cu-Al alloy-bonded Sm2Fe17N3 magnet which showed high coercivity revealed that the Sm-Fe-Cu-Al alloy had an effect of removing the surface oxide layer of the Sm2 Fe17N3 grains. However, the Sm-Fe-Cu-Al binder was contaminated by carbon and nitrogen, which originated from the organic solvent used as the milling medium during pulverization. To prevent carbon and nitrogen contamination, the Sm-Fe- Cu-Al alloy was added directly on the surface of the Sm2Fe17N3 grains by sputtering. Comparing the recovered coercivity per unit amount of the added binder the uncontaminated binder-coated sample had a higher coercivity recovery effect than the milled binder-added sample. These results suggested that sufficient addition of the contamination-free Sm-Fe-Cu-Al binder has the possibility to reduce the amount of binder necessary to produce a high coercive Sm2Fe17N3 magnet.

  11. Gd3Fe5O12 near the compensation temperature

    DEFF Research Database (Denmark)

    Hansen, Britt Rosendahl; Kuhn, Luise Theil; Bahl, Christian Robert Haffenden

    2010-01-01

    Applying a magnetic eld to a magnetic material will usually cause a change in the magnetic entropy of the material. If done adiabatically, the temperature of the material will change - this is the magnetocaloric eect. Gadolinium Iron Garnet (GdIG, Gd3Fe5O12) is a complex magnetic system with three...... magnetic sublattices, one Gd and two Fe. The Fe sites are strongly coupled antiferromagnetically, i.e. the magnetic moments are anti-parallel, while the Gd magnetic moment is weakly coupled antiferromagnetically to the resulting Fe moment. This results in a compensation temperature, where the total...

  12. Anomalous Hall effect in Fe/Gd bilayers

    KAUST Repository

    Xu, W. J.

    2010-04-01

    Non-monotonic dependence of anomalous Hall resistivity on temperature and magnetization, including a sign change, was observed in Fe/Gd bilayers. To understand the intriguing observations, we fabricated the Fe/Gd bilayers and single layers of Fe and Gd simultaneously. The temperature and field dependences of longitudinal resistivity, Hall resistivity and magnetization in these films have also been carefully measured. The analysis of these data reveals that these intriguing features are due to the opposite signs of Hall resistivity/or spin polarization and different Curie temperatures of Fe and Gd single-layer films. Copyright (C) EPLA, 2010

  13. From EuCARD to EuCARD-2

    CERN Multimedia

    Chaudron, M

    2013-01-01

    The one word that best describes the spirit of the EuCARD ’13 event (see here) that took place from 10 to 14 June at CERN is "collaboration". The event brought together more than 180 accelerator specialists from all over the world to celebrate the conclusion of the EuCARD project and to kick off its successor, EuCARD-2.   EuCARD-2 brings a global view to particle accelerator research in order to address challenges for future generations of accelerators. The project officially began on 1 May 2013 and will run for four years. With a total budget of €23.4 million, including an €8 million EU contribution, it will build upon the success of EuCARD and push it into an even more innovative regime. EuCARD-2 aims to significantly enhance multidisciplinary R&D for European accelerators and will actively contribute to the development of a European Research Area in accelerator science. This will be accomplished by promoting complementary expertise, cross-d...

  14. First-principles study of rare-earth (RE) cobaltites (RE=Nd,Sm,Gd,Dy,Er,Lu)

    Science.gov (United States)

    Topsakal, M.; Wentzcovitch, R. M.

    2014-12-01

    The lanthanide series of the periodic table comprises 15 members ranging from Lanthanum (La) to Lutetium (Lu). Although they are more abundant than silver, and some of them are more abundant than lead, they are known as rare-earth (RE) elements. The "rare" in their name refers to the difficulty of obtaining the pure elements, not to their abundances in nature. They are never found as free metals in the Earth's crust and do not exist as pure minerals. Using first-principles plane-wave calculations, we investigate the structural and electronic properties of rare-earth cobaltites (RECoO3). Structurally consistent Hubbard U treatment was shown to essential for proper description of strongly correlated cobalt-d electrons. We successfully capture the experimentally observed structural trends and give first-principles insights on interesting phenomena related with the cobalt spin state change. It was demonstrated that increase of crystal-field splitting energy between eg-t2g orbitals and shrinking of unoccupied σ*-bonding eg bands are responsible for the increase of onset spin-state transition temperature along the series.

  15. Octupole deformation in 149,151Sm nuclei

    International Nuclear Information System (INIS)

    Basu, S.; Chatterjee, J.M.; Banik, D.; Chattopadhyay, R.K.; Sharma, R.P.; Pardha Saradhi, S.K.

    1994-01-01

    Parity doublet states and alternating parity bands in 149,151 Sm nuclei observed in 148,150 Nd (α,3nγ) reactions at E α =37 and 35 MeV are presented here. Nineteen new transitions in 149 Sm and sixteen in 151 Sm have been observed in singles and γ-γ-t-r.f. coincidence experiments. Four alternating parity bands in 149 Sm and two in 151 Sm characterized by simplex quantum numbers are reported. The observed level schemes are interpreted in terms of octupole deformation. The energy difference due to parity splitting, collective rotational parameters, quasiparticle Routhians, single particle angular momentum alignments of bands with simplex quantum number s=±i in 149 Sm and with s=-i in 151 Sm have been calculated from the experimental results. From the E1, E2 branching ratios, the electric dipole moments are deduced to be left-angle D 0 right-angle=0.19±0.08 e fm for 149 Sm and left-angle D 0 right-angle=0.36±0.11 e fm for 151 Sm. The parameter C 1 , a function of the symmetry energy coefficient, has been estimated for 149 Sm from the liquid drop model of Strutinsky for deformed nucleus, and has been found to be C 1 =0.002003 -0.000159 +0.000087 fm

  16. EU-Russia Cultural Relations

    Directory of Open Access Journals (Sweden)

    Elena Sidorova

    2014-05-01

    Full Text Available This article analyzes the link between culture and diplomacy between Russia and the European Union, and shows the importance of cultural relations. It examines the common space of science, education and culture introduced at the 2003 EU-Russia Summit in St. Petersburg and the application of the principles of this concept that were established at the 2005 EU-Russia Summit in Moscow. It then considers EU-Russia collaboration on humanitarian action and the challenges that both parties face in this sphere. It also explains the formation of EU domestic and foreign cultural policy, and the role of European institutions and states in cultural affairs and diplomacy, as well as key elements and mechanisms of contemporary Russian foreign cultural policy. In addition, the article focuses on the European side of post-Soviet EU-Russia cultural relations. This cultural collaboration is defined as a competitive neighbourhood. EU and Russian interests collide: while Europeans try to promote their values, norms and standards within the framework of the European Neighbourhood Policy, Russia seeks to culturally influence and engage in this region for geostrategic and historical reasons. Finally, the article assesses the prospects for the EU-Russia cultural relations and emphasizes the role of ideology in improving such relations.

  17. ELECTRON CORRELATION-EFFECTS ON THE F(6)-MANIFOLD OF THE EU3+ IMPURITY IN BA2GDNBO6

    NARCIS (Netherlands)

    DIJKSTRA, F; DEJONG, WA; NIEUWPOORT, WC

    1995-01-01

    The effects of atomic and molecular electron correlation and Gaunt interaction on the transition energies between the D-5(0) and F-7(1,2) levels, arising from the (4)f(6) State of the europium ion, have been studied for the ion and for the [EuO6](9-) cluster as it is found in the Ba2GdNbO6 crystal.

  18. Synthesis and Characterization of Hollow Magnetic Alloy (GdNi2, Co5Gd Nanospheres Coated with Gd2O3

    Directory of Open Access Journals (Sweden)

    Wang Li

    2014-01-01

    Full Text Available Uniform magnetic hollow nanospheres (GdNi2, Co5Gd coated with Gd2O3 have been successfully prepared on a large scale via a urea-based homogeneous precipitation method using silica (SiO2 spheres as sacrificed templates, followed by subsequent heat treatment. Nitrogen sorption measurements and scanning electron microscope reveal that these hollow-structured magnetic nanospheres have the mesoporous shells that are composed of a large amount of uniform nanoparticles. After reduction treatment, these nanoparticles exhibit superparamagnetism that might have potential applications in medicine. Furthermore, the developed synthesis route may provide an important guidance for the preparation of other multifunctional hollow spherical materials.

  19. SM+Top at the LHC

    CERN Document Server

    McCarthy, Tom; The ATLAS collaboration

    2018-01-01

    This overview talk highlights some of the latest results by the ATLAS, CMS & LHCb collaborations. A particular focus is placed on some of the rarer Standard Model processes which have recently become accessible with the large set of proton-proton collision data collected during the successful second run of the LHC at $\\sqrt{s}$ = 13 TeV. Searches and cross-section measurements involving top quark signatures are given prominence, as well as those targeting highly boosted objects such as SM W/Z and Higgs bosons, and which consequently feature large-R jets and substructure techniques.

  20. EU Smart City Governance

    Directory of Open Access Journals (Sweden)

    Carmela Gargiulo

    2013-11-01

    Full Text Available In recent years European Commission has developed a set of documents for Members States tracing, directly or indirectly, recommendations for the transformation of the European city. The paper wants to outline which future EU draws for the city, through an integrated and contextual reading of addresses and strategies contained in the last documents, a future often suggested as Smart City. Although the three main documents (Cohesion Policy 2014-2020 of European Community, Digital Agenda for Europe and European Urban Agenda face the issue of the future development of European cities from different points of view, which are respectively cohesion social, ICT and urban dimension, each of them pays particular attention to urban and territorial dimension, identified by the name of Smart City. In other words, the paper aims at drawing the scenario of evolution of Smart Cities that can be delineated through the contextual reading of the three documents. To this end, the paper is divided into three parts: the first part briefly describes the general contents of the three European economic plan tools; the second part illustrates the scenarios for the future of the European city contained in each document; the third part seeks to trace the evolution of the Smart Cities issue developed by the set of the three instruments, in order to provide the framework of European Community for the near future of our cities. 

  1. Enhanced room temperature multiferroicity in Gd doped BFO

    CSIR Research Space (South Africa)

    Pradhan, SK

    2009-01-01

    Full Text Available deficient Gd doped multiferroic BFO system. At particular doping level of Gd, this bulk ceramics showed spectacular M~H behavior at room temperature which is likely to open a new avenue for the potential applications in information storing technology as well...

  2. The magnetic anisotropy of Gd-Y alloys

    Science.gov (United States)

    Phu Thuy, Nguyen; Verdonk, H. J.; Menovsky, A.; Franse, J. J. M.; Gersdorf, R.

    1983-02-01

    Magnetic torque curves on single crystals of Gd 1- xY x ( x ⩽ 0.1) show a reduction of the anomalous contribution that was observed in pure Gd, with increasing Y-content. Several explanations of this phenomenon are indicated in this paper.

  3. A metastable Mg11Sm phase obtained by rapid solidification

    International Nuclear Information System (INIS)

    Budurov, S.

    1993-01-01

    Molten Mg-Sm alloys with a Sm concentration of 4.93, 6.86, and 8.35 at.% were rapidly soldified with the aid of a shock wave gun device. Investigations of the obtained splats were performed with the aid of DSC, X-ray analysis, and metallography. Rapid soldification of the eutectic MgSm 8.35 alloy forms a new Im3m-type phase. (orig.)

  4. Chemical methods for Sm-Nd separation and its application in isotopic geological dating

    International Nuclear Information System (INIS)

    Guo Qifeng.

    1990-01-01

    Three chemical methods for Sm-Nd separation are mainly desribed: low chromatography of butamone-ammonium thiocyanate for hight concentration Sm and Nd separation, P 240 column chromatography for medium concentration Sm-Nd separation, and pressure ion exchange for low concentration Sm-Nd. The first Sm-Nd synchrone obtained in China with Sm-Nd methods is introduced and Sm-Nd isotopic geological dating in Early Archaean rocks in eastern Hebei has been determined

  5. Gaps in EU Foreign Policy

    DEFF Research Database (Denmark)

    Larsen, Henrik

    of Capability-Expectations Gap in the study of European foreign policy. Through examples from relevant literature, Larsen not only demonstrates how this concept sets up standards for the EU as a foreign policy actor (that are not met by most other international actors) but also shows how this curtails analysis......This book argues that theories of European foreign policy are performative: they create the objects they analyse. In this text, Larsen outlines the performativity approach to the role of theories based on the work of Derrida and goes on to examine the performative role of Christopher Hill's concept...... of EU foreign policy. The author goes on to discuss how the widespread use of the concept of ‘gap' affects the way in which EU foreign policy has been studied; and that it always produces the same result: the EU is an unfulfilled actor outside the realm of “normal” actors in IR. This volume offers new...

  6. Biosimilar regulation in the EU.

    Science.gov (United States)

    Kurki, Pekka; Ekman, Niklas

    2015-01-01

    In the EU, the EMA has been working with biosimilars since 1998. This experience is crystallized in the extensive set of guidelines, which range from basic principles to details of clinical trials. While the guidance may appear complicated, it has enabled the development of biosimilars, of which 21 have managed to get marketing authorization. Currently marketed biosimilars in the EU have a good track record in safety and traceability. No biosimilars have been withdrawn from the market because of safety concerns. The most controversial issues with biosimilars are immunogenicity and extrapolation of therapeutic indications. The available data for these topics do not raise concerns among EU regulators. Interchangeability and substitution are regulated by individual EU member states.

  7. GENERAL OVERWIEV ON EU ECONOMY

    Directory of Open Access Journals (Sweden)

    NICOLETA GEORGETA PANAIT

    2013-05-01

    Full Text Available The impact of the international economic crisis on new EU member states has proven to be more severe than the first estimates of the economic analysts. The situation is different for each Member State, the nature and the dimension of the challenges faced are not identical, and the pace of reform is not the same. The economic crisis has prompted intense and sustained action by the EU's national governments, the European Central Bank and the Commission. All have been working closely together to support growth and employment, ensure financial stability, and put in place a better governance system for the future. Sustainable development in the future is the common responsibility of all Member States and EU institutions, because our economies are closely interlinked, and the EU economic governance now reconfigured to provide more effective responses at the policy level, to give a good reaction to the present and the future challenges.

  8. Gd-DTPA-enhanced dynamic MR imaging of the kidney

    International Nuclear Information System (INIS)

    Choyke, P.L.; Frank, J.A.; Carvlin, M.J.; Austin, H.; Girton, M.J.; Inscoe, S.; Black, J.

    1988-01-01

    Dynamic Gd-DTPA-enhanced MR imaging potentially can provide both anatomic and physiologic information about the kidneys. The authors performed 42 animal imaging studies with 1.5-T MR imaging after a bolus of Gd-DTPA (0.1 mmol/kg) was given. A reproducible pattern of enhancement was observed that could be divided into three phases. In phase I a cortical blush was seen, representing intravascular contrast. Phase II represented the tubular concentration of Gd-DTPA and was depicted as a centrally migrating band that reversed direction in the inner medulla. Phase III was a gradual darkening of the inner medulla caused by concentration in the collecting ducts. This pattern was predictably altered by hydration status. The patterns observed reflected alterations in concentration of Gd-DTPA occurring in the renal tubules and collecting ducts. Gd-DTPA-enhanced renal MR imaging is promising as a renal imaging technique

  9. Ferrimagnetic properties of Co/(Gd-Co) multilayers

    International Nuclear Information System (INIS)

    Svalov, A.V.; Fernandez, A.; Vas'kovskiy, V.O.; Tejedor, M.; Barandiaran, J.M.; Orue, I.; Kurlyandskaya, G.V.

    2006-01-01

    Co/(Gd-Co) multilayers have been prepared by rf-sputtering and investigated by means of Transverse Magnetooptic Kerr Effect (TMOKE), SQUID and VSM magnetometry. The composition of amorphous Gd 0.36 Co 0.64 layers was chosen so that their saturation magnetization was dominated by Gd moments in all the temperature range. Co and Gd-Co layers formed a macroscopic ferrimagnetically coupled system displaying a compensation temperature. Complete magnetic moment compensation was found at such point. An inversion of TMOKE hysteresis loops and a divergent behaviour of coercivity were also observed. By changing the layers thickness it has been possible to control the magnetic characteristics of the Co/(Gd-Co) structures, in particular the compensation takes place at different temperatures

  10. Fabrication of (U,Gd)O{sub 2} pellets and development of method for Gd content measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. S.; Song, K. W.; Kang, K. W.; Yang, J. H.; Kim, J. H.; Lee, C. B. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-05-01

    The goals of the investigation reported herein are to develope the recycling process of defective (U,Gd)O{sub 2} pellets and quality analysis method of sintered (U,Gd)O{sub 2} pellet. (U,Gd){sub 3}O{sub 8} powder is produced by oxidizing defective pellet then mixed with UO{sub 2} and Gd{sub 2}O{sub 3} powder. The mixed powder is milled, pressed and sintered to fabricate (U,Gd)O{sub 2} pellet. In above recycling process, (U,Gd){sub 3}O{sub 8} powder properties and milling condition are greatly affect the final sintered pellet quality of (U,Gd)O{sub 2}. The effects of oxidation temperature and time on powder property of recycled (U,Gd){sub 3}O{sub 8}, and milling method and time of powder mixture on sintered pellet property were investigated. The mixture had Gd{sub 2}O{sub 3} contents of 6 and 10wt% and also had recycled (U,Gd){sub 3}O{sub 8} contents of between 0 to 20wt%, respectively. The properties of sintered pellet such as density, grain size, fraction of cluster, Gd homogeneity are analysed and compared with those of pellets produced by foreign companies. The result shows that our pellet quality is compatible with or better than imported pellets. The more simple and effective way to measure the Gd contents in (U,Gd)O{sub 2} sintered pellet was invented. In first, we oxidized a certain amount of (U{sub 1-x}Gd{sub x})O{sub 2+z} pellet to (U{sub 1-x}Gd{sub x}){sub 3}O{sub 8} powder by annealing between 400{approx}950 .deg. C in air and measured the weight of it(W{sub 1}). And then annealing temperature raised to higher than 950 .deg. C and measured the weight of specimen(W{sub 2}). We found that (U{sub 1-x}Gd{sub x}){sub 3}O{sub 8} phase separated into (U{sub 1-y}Gd{sub y}){sub 4}O{sub 9} and U{sub 3}O{sub 8} in this annealing stage. In addition, the Gd atomic fraction in (U{sub 1-y}Gd{sub y}){sub 4}O{sub 9}, that is y, is independent of initial Gd contents x and has a fixed value. Using above described relations, we can finally found that {chi} in (U{sub 1-x}Gd

  11. Preparation and biodistribution of 153Sm-HEDTMP

    International Nuclear Information System (INIS)

    Jiang Shubin; Luo Shunzhong; Bing Wenzeng; Wang Wenjin; Wei Hongyuan; Hu Shu; Deng Houfu; Lei Yong

    2003-01-01

    HEDTMP (N-(2-hydroxyethyl) ethlenediamine-1,1,2-tri(methylene phosphonic acid)) was synthesized and labeled with 153 Sm. The labelling condition, stability, molar ratio of 153 Sm to HEDTMP, rabbit bone imaging and biodistribution of 153 Sm-HEDTMP in mice were investigated. The results showed that weak basic media and high concentration ligand were favorable to form 153 Sm-HEDTMP, and neutral or weak basic media increased stability of 153 Sm-HEDTMP. The higher the concentration of HEDTMP, the more stable the labelled complex. The results also indicated that the chemical mole ratio of 153 Sm-HEDTMP was 153 Sm:HEDTMP=1:1 and the skeleton uptake of 153 Sm-HEDTMP was high ((25.68 ± 1.22)ID%/g bone at 3h and (16.56 ± 1.01)ID%/g bone at 48h post-injection) while the nontarget tissue uptake is low. Therefore, 153 Sm-HEDTMP may be a promising bone tumor therapeutic agent

  12. SM-2 reactor potentialities for investigation of fusion reactor materials

    International Nuclear Information System (INIS)

    Tsykanov, V.A.; Samsonov, B.V.; Markina, N.V.; Polyakov, Yu.N.; Sluzhaev, V.I.; Losev, N.P.; Lobanov, G.P.

    1981-01-01

    The possibility of utilization of the SM-2 type reactors for fusion reactor (FR) materials testing is discussed. The measuring and calculational results, while estimating irradiation conditions in the SM-2 reactor channels, are given. The basic characteristics, necessary for correct simulation of FR parameters in fission reactors such as neutron flux density, radiation damage in the shift per atom values, gas accumulation, are considered. The characteristics of existing and tested in the SM-2 reactor investigational methods for studying structural and isolation materials are given. The conclusion about the possibility of SM-2 reactor utilization for the FR materials testing is made [ru

  13. Benefits of Gd for High Energy Neutrinos in SuperK-Gd

    Science.gov (United States)

    Fernández, Pablo; Super-Kamiokande Collaboration

    2017-09-01

    The SuperK-Gd project is the approved upgrade of the Super-Kamiokande (SK) detector in order to enable it to efficiently (> 80%) detect thermal neutrons by dissolving 0.2% of gadolinium sulphate (Gd2(SO4)3) into its water. This ability has also significant advantages in the analysis of high energy (> 102 MeV) neutrinos in SK, namely atmospheric and long baseline neutrinos from T2K. Here we present the improvements due to the use of the tagged final state neutrons in the separation of the interacting neutrinos and antineutrinos, the distinction between Neutral Current and Charged Current neutrino interactions, and the neutrino energy reconstruction. We study the impact of those features on both, atmospheric and long baseline neutrino oscillation analyses.

  14. Search for superdeformation in 144Gd

    International Nuclear Information System (INIS)

    Vivien, J.P.; Nourreddine, A.; Beck, F.A.; Byrski, T.; Gehringer, C.; Haas, B.; Merdinger, J.C.; Dudek, J.; Nazarewicz, W.

    1986-01-01

    Quasi-continuum γ-decay studies of 144 Gd have been performed using the 120 Sn( 28 Si,4n)reaction at 125, 135, 145 and 155 MeV bombarding energies. Angular distribution and multiplicity measurements have been done at the above energies. At 145 MeV bombarding energy a lifetime measurement has also been performed. Although a collective behaviour has been observed, the present data do not give evidence for population of superdeformed rotational bands. Theoretical interpretation using the cranking model with the Woods-Saxon field is given. The effects of temperature and pairing on the superdeformed configuration are discussed; superdeformation effects are predicted to disappear below I ∼ 60-70 ℎ when temperature exceeds ∼ 500 KeV

  15. New perspective for GdNCT. Gd-DTPA reaches the nucleus of glioblastoma cells in culture and in vivo

    International Nuclear Information System (INIS)

    Stasio, G. de; Gilbert, B.; Frazer, B.H.

    2000-01-01

    We investigated the prospects of gadolinium as a neutron capture therapy agent by combining three independent techniques to study the uptake of Gd-DTPA in vitro, in cultured glioblastoma cells, and in vivo, in the glioblastoma tissue sections after injection of Gd-DTPA and tumor extraction. We show that gadolinium not only penetrates the plasma membrane of glioblastoma cells grown in culture, but we also observe a statistically significant higher concentration of Gd in the nucleus relative to the cytoplasm. For the in vivo experiments, Gd-DTPA was administered to 6 glioblastoma patients before neurosurgery. The extracted bioptic tissue was then analyzed with spectromictroscopy, showing Gd localized in the nuclei of glioblastoma cells in 5 patients out of the 6 analyzed. (author)

  16. Synthesis, characterization and thermal behavior: Gd(NO3)3.6H2O to Gd2O3

    International Nuclear Information System (INIS)

    Ghonge, Darshana K.; Sheelvantra, Smita S.; Kalekar, Bhupesh B.; Raje, Naina

    2015-01-01

    Gadolinium oxide finds its application in nuclear as well as medical industry. It has been prepared from the thermal decomposition of gadolinium nitrate hexahydrate. Surface area of the synthesized compound was measured as 19 m 2 /g. EDS data shows only the presence of gadolinium and oxygen in the synthesized compound with the Gd to O ratio as calculated for Gd 2 O 3 , suggests the formation of pure Gd 2 O 3 . XRD analysis confirms the formation of pure cubic phase Gd 2 O 3 . In the absence of any report on the thermal behavior of GdNH, present studies have been carried out to understand the decomposition mechanism using simultaneous TG - DTA - EGA measurements

  17. Test of E1-radiative strength function and level density models by 155 Gd (n,2γ) 156 Gd reaction

    International Nuclear Information System (INIS)

    Voinov, A.V.

    1996-01-01

    The information about the level density of 156 Gd nucleus and strength functions of γ transitions extracted from two γ-cascade spectra of the 155 Gd (n,2γ) 156 Gd reaction is analyzed. The method of statistical simulation of γ-cascade intensity is applied for calculation of the main parameters of experimental spectra. The method is used to extract the information on the E1-radiative strength function of γ transitions and level density in the 156 Gd nucleus. It is shown that at an excitation energy above 3 MeV the level density of 156 Gd nucleus must decrease in comparison with that calculated within the Fermi gas model. Its is concluded that possible explanation of the observed effect is connected with the influence of pairing correlations on the level density in nuclei

  18. Små dimser med store potentialer

    DEFF Research Database (Denmark)

    Mikkelsen, Bent Egberg; Dobroczynski, Michal; Gade, Rikke

    2015-01-01

    Fødevare- og medialogiforskere på Aalborg Universitet har de seneste år udviklet og testet en række intelligente enheder. Fælles for dem er, at de er små og kan håndtere store mængder af data om forbrugernes adfærd. Et eksempel er FoodScape Tracker, som i realtid samarbejder med forbrugeren om, h......, hvad denne spiser. En anden ny enhed er Virtual Food Choice Simulator, som virtuelt kan simulere fødevareomgivelser i form af buffeter og supermarkeder uden udgifter til ombygning og fødevarer, og derved vise, hvad forbrugerne ser og ikke ser....

  19. INTERACTION MODE BETWEEN METHYLENE BLUE-Sm(III ...

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT. Spectroscopic and viscosity methods were applied to investigate the interaction between methylene blue (MB)-Sm(III) complex and herring sperm DNA by using acridine orange as a spectral probe in Tris-HCl buffer (pH 7.40). By means of molar ratio method, the binding ratios between MB-Sm(III) and DNA ...

  20. Symmetries for SM Alignment in multi-Higgs Doublet Models

    CERN Document Server

    Pilaftsis, Apostolos

    2016-01-01

    We derive the complete set of maximal symmetries for Standard Model (SM) alignment that may occur in the tree-level scalar potential of multi-Higgs Doublet Models, with $n > 2$ Higgs doublets. Our results generalize the symmetries of SM alignment, without decoupling of large mass scales or fine-tuning, previously obtained in the context of two-Higgs Doublet Models.

  1. Interaction mode between methylene blue-Sm(III) complex and ...

    African Journals Online (AJOL)

    Spectroscopic and viscosity methods were applied to investigate the interaction between methylene blue (MB)-Sm(III) complex and herring sperm DNA by using acridine orange as a spectral probe in Tris-HCl buffer (pH 7.40). By means of molar ratio method, the binding ratios between MB-Sm(III)and DNA were determined ...

  2. Sm 3 + phosphor as orange-red emitting material

    Indian Academy of Sciences (India)

    Sm 3 + -activated NaSrPO4 phosphors could be efficiently excited at 403 nm, and exhibited a bright red emission mainly including four wavelength peaks of 565, 600, 646 and 710 nm. The highest emission intensity was foundfor NaSr 1 − x PO 4 : x Sm 3 + with a composition of x = 0.007 . Concentration quenching was ...

  3. 31 CFR 208.5 - Availability of the ETA SM.

    Science.gov (United States)

    2010-07-01

    ... as Treasury's Financial Agent for the offering of the account pursuant to Public Law 104-208... offers ETAs SM. Any Federally-insured financial institution shall be eligible, but not required, to offer ETAs SM as Treasury's Financial Agent. A Federally-insured financial institution that elects to offer...

  4. Magnetoelastic behaviour of Gd sub 5 Ge sub 4

    CERN Document Server

    Magen, C; Algarabel, P A; Marquina, C; Ibarra, M R

    2003-01-01

    A complete investigation of the complex magnetic behaviour of Gd sub 5 Ge sub 4 by means of linear thermal expansion and magnetostriction measurements (5-300 K, 0-120 kOe) has been carried out. Our results support the suggested existence in this system of a coupled crystallographic-magnetic transition from a Gd sub 5 Ge sub 4 -type Pnma (antiferromagnetic) to a Gd sub 5 Si sub 4 -type Pnma (ferromagnetic) state. Strong magnetoelastic effects are observed at the field-induced first-order magnetic-martensitic transformation. A revised magnetic and crystallographic H- T phase diagram is proposed.

  5. Magnetic transitions and thermomagnetic properties of GdCu6

    International Nuclear Information System (INIS)

    Chattopadhyay, M.K.; Arora, P.; Mondal, P.; Roy, S.B.

    2010-01-01

    We report results of dc magnetization and specific heat studies focusing on the paramagnetic to antiferromagnetic transition in GdCu 6 . These results clearly reveal the evidences of multiple magnetic transitions in GdCu 6 . In addition, a marked thermomagnetic irreversibility is observed in the temperature dependence of magnetization in low ( 6 is quite large in the temperature regime below 20 K, which indicates to the potential of GdCu 6 as a magnetic regenerator material for cryocooler related applications. Isothermal magnetic entropy change estimated from the results of magnetization and specific heat measurements shows a change in sign at the antiferromagnetic ordering temperature.

  6. Phantom and animal studies of a new hepatobiliary agent for MR imaging: comparison of Gd-DTPA-DeA with Gd-EOB-DTPA.

    Science.gov (United States)

    Yoshikawa, Kohki; Inoue, Yusuke; Akahane, Masaaki; Shimada, Morio; Itoh, Sayaka; Seno, Atsushi; Hayashi, Sanshin

    2003-08-01

    To investigate the characteristics of Gd-DTPA-DeA as a hepatobiliary contrast agent for MR imaging in comparison with those of Gd-EOB-DTPA. We undertook phantom experiments to assess T1 relaxivity for Gd-DTPA-DeA, Gd-EOB-DTPA, and Gd-DTPA in human plasma. For Gd-DTPA-DeA and Gd-EOB-DTPA, we evaluated the contrast effect in rats using an SPGR sequence. The contrast ratios of liver and abdominal aorta were measured up to 21 minutes after intravenous administration of the agents. Visualization of the bile duct and renal pelvis was also assessed. In human plasma, T1 relaxivity was similar for Gd-DTPA-DeA and Gd-EOB-DTPA, and higher than those for Gd-DTPA. Whereas the contrast ratio of liver peaked about five minutes after the injection of Gd-EOB-DTPA and was followed by a subsequent decline, a continuous rise was shown for Gd-DTPA-DeA, resulting in a larger maximal contrast effect. Contrast ratios of the abdominal aorta were larger for Gd-DTPA-DeA. Biliary excretion was observed for both agents but occurred earlier with Gd-EOB-DTPA. While renal excretion was shown for all rats three minutes after the injection of Gd-EOB-DTPA, it was not observed for Gd-DTPA-DeA. Gd-DTPA-DeA may be used as a hepatobiliary contrast agent and shows different pharmacokinetics from Gd-EOB-DTPA. Copyright 2003 Wiley-Liss, Inc.

  7. Thermodynamic calculation of Al-Gd and Al-Gd-Mg phase equilibria checked by key experiments

    International Nuclear Information System (INIS)

    Groebner, J.; Kevorkov, D.; Schmid-Fetzer, R.

    2001-01-01

    The binary Al-Gd and the ternary Al-Gd-Mg systems were calculated using the Calphad method. It is demonstrated that previous interpretation of ternary liquidus temperatures below 700 C must be related to other phase equilibria. The actual ternary liquidus temperatures are much higher, up to some 600 C above the previous interpretation in literature. They are widely governed by the high-melting compounds Al 2 Gd and Al 3 Gd with liquidus surfaces stretching far into the ternary system. A small number of key experiments in this work confirmed the calculated liquidus temperature and the phase relations. The available experimental data in literature fit excellently with the calculation in the binary Al-Gd system. In the ternary Al-Gd-Mg system, which is shown in several sections of the phase diagram, a good agreement can be observed too, considering the necessary reinterpretation of the liquidus temperatures suggested by Rokhlin et al. Ternary solubilities were not found experimentally. The ternary compound Al 4 GdMg (τ) forms in a ternary peritectic reaction at 761 C. (orig.)

  8. Detection of antifungal properties in Lactobacillus paracasei subsp. paracasei SM20, SM29, and SM63 and molecular typing of the strains.

    Science.gov (United States)

    Schwenninger, Susanne Miescher; von Ah, Ueli; Niederer, Brigitte; Teuber, Michael; Meile, Leo

    2005-01-01

    Lactobacilli isolated from different food and feed samples such as raw milk, cheese, yoghurt, olives, sour dough, as well as corn and grass silage, were screened for their antifungal activities. Out of 1,424 isolates tested, 82 were shown to be inhibitory to different yeasts (Candida spp. and Zygosaccharomyces bailii) and a Penicillium sp., which were previously isolated from spoiled yoghurt and fruits. Carbohydrate fermentation patterns suggested that a substantial portion, 25%, belonged to the Lactobacillus casei group, including L. casei, L. paracasei, and L. rhamnosus. The isolates SM20 (DSM14514), SM29 (DSM14515), and SM63 (DSM14516) were classified by PCR using species-specific primers to target the corresponding type strains (L. casei, L. paracasei, and L. rhamnosus) as controls. Further molecular typing methods such as randomly amplified polymorphic DNA, pulsed-field gel electrophoresis, and sequencing analysis of the 16S rRNA gene allowed classifying strains SM20, SM29, and SM63 as L. paracasei subsp. paracasei in accordance with the new reclassification of the L. casei group proposed by Collins et al.

  9. Assessment of microseeds biodegradability of Sm and Sm:Ba splenic implants in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, Savio Lana; Barroso, Thiago Vinicius Villar [Faculdade de Ciencias Medicas de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Anatomia; Campos, Tarcisio P.R., E-mail: campos@nuclear.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Ciencias e Tecnicas Nucleares

    2009-07-01

    The radioactive interstitial implants have applications in controlling neoplasm in several regions of the human body. Currently the permanent brachytherapy seeds implanted in the spleen and other organs are made of I-125 seeds. After the total emission of radiation, the metal encapsulated seed remains inert in the implanted area. Seeds of bioactive ceramics have been prepared with Sm-152 incorporation to be activated in Sm-153. This study aimed to develop surgical technique for implanting biodegradable micro-seeds in the spleen of the rabbit. Three micro-seeds were introduced by hypodermic needle in the spleen in eight rabbits by median laparotomy. Subsequently, there were clinical and functional reactions of the animal to the implanted foreign body. The other objective was to perform the animal monitoring by radiography, produced in time sequence, and pathological studies of a fragment of the spleens of rabbits. The results show the effectiveness of surgery, the identification of the implanted material by radiography in vivo, and the biocompatibility of micro-seeds most of Sm and Sm:Ba. These seeds of reduced volume, 0.3x 1.6 mm, could be monitored for radiological studies in 2 periods: early and later implant. On the later studies, radiography was taken at 60d post-implant. Biopsies were taken and radiographs of the samples were also performed for evidencing the degradation state of the seeds. The results of the two groups of four rabbits are presented. They show partial degradation of the seed verified by radiographic contrast which is related to the atomic number of the elements and mass density in the seed. The biopsy showed that the ceramic is clearly absorbed by the spleen tissue and form tissue-implant interface. The histological slides showed an inflammatory reaction with presence of fibrosis of the giant cell foreign body. In conclusion, the radiograph shows a suitable noninvasive technique for monitoring the degradation of micro-seed ceramics in vivo

  10. Assessment of microseeds biodegradability of Sm and Sm:Ba splenic implants in rabbits

    International Nuclear Information System (INIS)

    Siqueira, Savio Lana; Barroso, Thiago Vinicius Villar; Campos, Tarcisio P.R.

    2009-01-01

    The radioactive interstitial implants have applications in controlling neoplasm in several regions of the human body. Currently the permanent brachytherapy seeds implanted in the spleen and other organs are made of I-125 seeds. After the total emission of radiation, the metal encapsulated seed remains inert in the implanted area. Seeds of bioactive ceramics have been prepared with Sm-152 incorporation to be activated in Sm-153. This study aimed to develop surgical technique for implanting biodegradable micro-seeds in the spleen of the rabbit. Three micro-seeds were introduced by hypodermic needle in the spleen in eight rabbits by median laparotomy. Subsequently, there were clinical and functional reactions of the animal to the implanted foreign body. The other objective was to perform the animal monitoring by radiography, produced in time sequence, and pathological studies of a fragment of the spleens of rabbits. The results show the effectiveness of surgery, the identification of the implanted material by radiography in vivo, and the biocompatibility of micro-seeds most of Sm and Sm:Ba. These seeds of reduced volume, 0.3x 1.6 mm, could be monitored for radiological studies in 2 periods: early and later implant. On the later studies, radiography was taken at 60d post-implant. Biopsies were taken and radiographs of the samples were also performed for evidencing the degradation state of the seeds. The results of the two groups of four rabbits are presented. They show partial degradation of the seed verified by radiographic contrast which is related to the atomic number of the elements and mass density in the seed. The biopsy showed that the ceramic is clearly absorbed by the spleen tissue and form tissue-implant interface. The histological slides showed an inflammatory reaction with presence of fibrosis of the giant cell foreign body. In conclusion, the radiograph shows a suitable noninvasive technique for monitoring the degradation of micro-seed ceramics in vivo

  11. EU Legitimacy and Social Affiliation

    DEFF Research Database (Denmark)

    Gunnarsson, Jan Sture Gunnar

    2009-01-01

    Analyses of European governance usually put the member states in the foreground, placing the citizens in the background. This article brings explanations of EU legitimacy down to the level of individuals. A method is suggested that combines explanations based on individual interests and a sociolo......Analyses of European governance usually put the member states in the foreground, placing the citizens in the background. This article brings explanations of EU legitimacy down to the level of individuals. A method is suggested that combines explanations based on individual interests...

  12. EU Policy. A Debate on EU Energy Policy

    International Nuclear Information System (INIS)

    Cohen, R.; Kjoelbye, L.; Aaslund, A.; Zwitserloot, R.

    2008-01-01

    Views from four experts in the field of energy on the EU's energy policy, as laid down in the Third Package, are presented. Kjoelbye and Cohen argue about the pros and cons of unbundling, Aaslund defends the policy of reciprocity towards Gazprom, and Zwitserloot warns that Europe's anti-Gazprom policy endangers security of supply

  13. Neutronic analysis of Gd2O3 as burnable poison

    International Nuclear Information System (INIS)

    Lecot, C.A.

    1990-01-01

    For the reactors core design, the use of burnable poisons is one of the options for the control of in excess reactivity and the power form factor. As alternative procedures, the absorbing material may be included in pellets of an inert material or in fuel pellets. Besides, a cladding material and the locations of the fuel elements must be chosen for the first case. The CAREM reactor core design foresees the use of gadolinium oxide (Gd 2 O 3 ) as burnable poison. In this work, a comparative study was made, from the neutronic point of view, among the following alternatives for the poisons location: a) Gd 2 O 3 bars supports in alumina (Al 2 O 3 ), sheathed in steel; b) Gd 2 O 3 bars supports in alumina sheathed in Zry-4; c) Gd 2 O 3 in uranium dioxide (UO 2 ) fuel pellets. (Author) [es

  14. Electronic Structure of GdCuGe Intermetallic Compound

    Science.gov (United States)

    Lukoyanov, A. V.; Knyazev, Yu. V.; Kuz'min, Yu. I.

    2018-04-01

    The electronic structure of GdCuGe intermetallic compound has been studied. Spin-polarized energy spectrum calculations have been performed by the band method with allowance for strong electron correlations in the 4 f-shell of gadolinium ions. Antiferromagnetic ordering of GdCuGe at low temperatures has been obtained in a theoretical calculation, with the value of the effective magnetic moment of gadolinium ions reproduced in fair agreement with experimental data. The electronic density of states has been analyzed. An optical conductivity spectrum has been calculated for GdCuGe; it reveals specific features that are analogous to the ones discovered previously in the GdCuSi compound with a similar hexagonal structure.

  15. Electron impact excitation of Gd XXXVII

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, K.M.; Keenan, F.P. [Dept. of Pure and Applied Physics, Queen' s Univ., Belfast (United Kingdom); Norrington, P.H.; Bell, K.L. [Dept of Applied Maths. and Theoretical Physics, Queen' s Univ., Belfast (United Kingdom); Pert, G.J. [Dept. of Physics, York Univ., York (United Kingdom); Rose, S.J. [Plasma Physics Group, Rutherford Appleton Lab., Oxon (United Kingdom)

    2000-01-01

    Energy levels and radiative rates for transitions among the 107 fine-structure levels belonging to the (1s{sup 2}2s{sup 2}2p{sup 6}) 3s{sup 2}3p{sup 6}3d{sup 10}, 3s{sup 2}3p{sup 6}3d{sup 9}4l, 3s{sup 2}3p{sup 5}3d{sup 10}4l, and 3s3p{sup 6}3d{sup 10}4l configurations of Ni-like Gd XXXVII have been calculated using the GRASP code. The collision strengths have also been computed but among the lowest 59 levels only, at 4 representative energies of 200, 400, 600 and 800 Ryd, using the Dirac Atomic R-matrix code. Detailed calculations for collision strengths and rate coefficients are in progress. (author)

  16. Trial of MR cholangiopancreatography combined with Gd-DTPA

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Koshi; Ha-Kawa, S.K.; Kurokawa, Hiroaki; Nakano, Yoshihisa; Tanaka, Yoshimasa [Kansai Medical Univ., Moriguchi, Osaka (Japan); Asakura, Tamaki; Maeda, Toshihiko; Ohshima, Taichi

    1997-08-01

    Gd-DTPA can be used as a negative contrast agent on T2-weighted images because of T2 shortening effect. Fast asymmetric spin echo (FASE) sequences were used on magnetic resonance cholangiopancreatography (MRCP). Precontrast images showed high signal intensity in choledochalpancreatic venous plexus, which aggravated visualization of the bile duct and pancreatic duct. Intravenous administration of Gd-DTPA reduced signal intensity in pericholedochal or peripancreatic small veins, and improved image quality of MRCP. (author)

  17. GdF in Hungary: the East in progress

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    After Germany and the Czech Republic, Gaz de France (GdF) has decided to export its know-how and technologies about natural gas into Hungary. Thanks to the Hungarian privatization program started in 1995, GdF could obtain the major participation in the Degaz and Egaz companies, two out of the five local distribution companies, and controls 22% of the natural gas distribution in Hungary. (J.S.)

  18. Evaluation of hypothetical (153)Gd source for use in brachytherapy.

    Science.gov (United States)

    Ghorbani, Mahdi; Behmadi, Marziyeh

    2016-01-01

    The purpose of this work is to evaluate the dosimetric parameters of a hypothetical (153)Gd source for use in brachytherapy and comparison of the dosimetric parameters with those of (192)Ir and (125)I sources. Dose rate constant, the radial dose function and the two dimensional (2D) anisotropy function data for the hypothetical (153)Gd source were obtained by simulation of the source using MCNPX code and then were compared with the corresponding data reported by Enger et al. A comprehensive comparison between this hypothetical source and a (192)Ir source with similar geometry and a (125)I source was performed as well. Excellent agreement was shown between the results of the two studies. Dose rate constant values for the hypothetical (153)Gd, (192)Ir, (125)I sources are 1.173 cGyh(-1) U(-1), 1.044 cGyh(-1) U(-1), 0.925 cGyh(-1) U(-1), respectively. Radial dose function for the hypothetical (153)Gd source has an increasing trend, while (192)Ir has more uniform and (125)I has more rapidly falling off radial dose functions. 2D anisotropy functions for these three sources indicate that, except at 0.5 cm distance, (192)Ir and (125)I have more isotropic trends as compared to the (153)Gd source. A more uniform radial dose function, and 2D anisotropy functions with more isotropy, a much higher specific activity are advantages of (192)Ir source over (153)Gd. However, a longer half-life of (153)Gd source compared to the other two sources, and lower energy of the source with respect to (192)Ir are advantages of using (153)Gd in brachytherapy versus (192)Ir source.

  19. Conversion of VUV to visible in K{sub 5}Li{sub 2}LnF{sub 10} containing rare-earth ions (Ln=Pr-Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Solarz, P.; Dominiak-Dzik, G.; Ryba-Romanowski, W

    2004-01-14

    Potential of single crystals of K{sub 5}Li{sub 2}LnF{sub 10} for application as VUV excited phosphors has been examined. The crystals can be doped by rare-earth ions (Pr-Gd) with concentrations up to 100 at.% keeping a minimal distance between two of the nearest rare-earth ions superior to 6.5 Angst. For this reason the efficiency of self-quenching of their luminescence is greatly reduced. Luminescence spectra and excitation spectra in the 50-250 nm spectral region have been recorded at room temperature. Intense visible and UV emission excited in the VUV region has been observed in crystals containing Nd, Eu and Gd. Slightly weaker emission in crystals containing praseodymium and markedly weaker emission in crystals containing samarium has been recorded and attributed to enhanced selfquenching of luminescence. Tentative assignment of spectra has been proposed.

  20. Radiation damage in CaF2: Gd

    International Nuclear Information System (INIS)

    Prado, L.

    1979-01-01

    Calcium fluoride crystals doped with Gd 3+ at four different concentrations were irradiated at room temperature. The damage produced by radiation and the primary and secondary effects as well were studied by optical spectroscopy. The increase in optical absorption (with loss of transparency) varied from sample as a function of concentration and dose. The coloration curves showed an evolution from two to three radiation damage steps when going from a pure to the most Gd 3+ concentrated sample. The obtained spectra were analysed at characteristic wave lenghts of electronic defects (photochromic centers, F and its aggregates) and of Gd 3+ and Gd 2+ defects. As a result of the radiation damage the valence change (Gd 3+ →Gd 2+ ) and its reversible character under thermal activation were directly observed. These effects were correlated with other observed effects such as the room temperature luminescence after the irradiation ceased. The non radiative F centers formation from the interaction of holes and photochromic centers was also observed and analysed. A thermal activation study of the several defects responsible for the different absorption bands was made. Values of activation energies were obtained as expected for the kind of defects involved in these processes [pt

  1. Investigation of nanocrystalline Gd films loaded with hydrogen

    KAUST Repository

    Hruška, Petr

    2015-01-01

    The present work reports on microstructure studies of hydrogen-loaded nanocrystalline Gd films prepared by cold cathode beam sputtering on sapphire (112¯0) substrates. The Gd films were electrochemically step-by-step charged with hydrogen and the structural development with increasing concentration of absorbed hydrogen was studied by transmission electron microscopy and in-situ   X-ray diffraction using synchrotron radiation. The relaxation of hydrogen-induced stresses was examined by acoustic emission measurements. In the low concentration range absorbed hydrogen occupies preferentially vacancy-like defects at GBs typical for nanocrystalline films. With increasing hydrogen concentration hydrogen starts to occupy interstitial sites. At the solid solution limit the grains gradually transform into the ββ-phase (GdH2). Finally at high hydrogen concentrations xH>2.0xH>2.0 H/Gd, the film structure becomes almost completely amorphous. Contrary to bulk Gd specimens, the formation of the γγ-phase (GdH3) was not observed in this work.

  2. A new entry in GdNCT. The nanodosimetry

    International Nuclear Information System (INIS)

    Cerullo, Nicola; Bufalino, Domenico; Esposito, Juan

    2006-01-01

    The GdNCT is a recently proposed therapy, mainly based on the action of Auger and IC electrons, generated by 157 Gd after neutron activation. The energy carried out by these electrons is limited to about 1% of total energy of the reaction, but due to high electron LET, if the emitter is bound to DNA, their action is very effective. Some Gd compounds have the property to be bound to DNA. Therefore the evaluation of the DNA damage caused by the Gd-emitted electrons is a key issue. The DNA damage is due to almost double strand breaks (DSB) in the DNA double helix chain. The dimensions concerned are of the order of 2 to 3 nm. Therefore, in the study of GdNCT, besides macro and micro, we must use the new 'nanodosimetry', based on particle interactions in the nanometric sites. A general review on GdNCT state of the art and on the nanometric Monte Carlo computing techniques, applied to a DNA model, is here presented. (author)

  3. J.sub.c./sub.-B performance study of an OCMG (Nd-EU-GD)-123 material doped by sub-micrometre Gd-211 particles

    Czech Academy of Sciences Publication Activity Database

    Jirsa, Miloš; Muralidhar, M.; Murakami, M.; Noto, K.; Nishizaki, T.; Kobayashi, N.

    2001-01-01

    Roč. 14, - (2001), s. 50-57 ISSN 0953-2048 R&D Projects: GA AV ČR IAA1010919 Institutional research plan: CEZ:AV0Z1010914 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.511, year: 2001

  4. Effect of nanoscopic ZrO.sub.2./sub. particles on flux pinning in (Nd,Eu,Gd)-123/Gd-211 composites

    Czech Academy of Sciences Publication Activity Database

    Muralidhar, M.; Sakai, N.; Jirsa, Miloš; Murakami, M.; Koshizuka, N.

    2004-01-01

    Roč. 17, - (2004), s. 1129-1132 ISSN 0953-2048 Institutional research plan: CEZ:AV0Z1010914 Keywords : ZrO 2 particles pinning by nanoscopic particles * high T c superconductor s * melt-textured compounds Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.556, year: 2004

  5. EU Legitimacy and Social Affiliation

    DEFF Research Database (Denmark)

    Gunnarsson, Jan Sture Gunnar

    Analyses of European governance usually bring the member states into the fore placing the citizens in the background. By means of economic analysis, this paper brings explanations of EU legitimacy down to the level of individuals. A method will be suggested that combines explanations based...

  6. Coping with EU environmental legislation

    DEFF Research Database (Denmark)

    Anker, Helle Tegner; de Graaf, Kars; Purdy, Ray

    2015-01-01

    and Denmark. It also examines how EU initiatives may influence these principles and practices. The article concludes that the steering of transposition processes by general transposition principles and objectives alone, and in particular those dominated by a ‘burden reducing’ agenda, has a limited focus...

  7. EU citizenship and direct taxation

    NARCIS (Netherlands)

    E.W. Ros (Erik)

    2017-01-01

    markdownabstractThe main question addressed in this study is: _How has the concept of EU citizenship influenced the legal autonomy of Member States; most notably in the field of direct taxation and are the implications of that influence on the tax autonomy of Member States acceptable?_

  8. EU Legitimacy and Social Affiliation

    DEFF Research Database (Denmark)

    Gunnarsson, Jan Sture Gunnar

    2009-01-01

    Analyses of European governance usually put the member states in the foreground, placing the citizens in the background. This article brings explanations of EU legitimacy down to the level of individuals. A method is suggested that combines explanations based on individual interests and a sociolo...

  9. Fundamentals of EU VAT law

    NARCIS (Netherlands)

    van Doesum, A.; van Kesteren, H.W.M.; van Norden, G.J.

    Fundamentals of EU VAT Law aims at providing a deep insight into the systematics, the functioning and the principles of the European Value Added Tax (VAT) system. VAT is responsible for generating approximately EUR 903 billion per year in tax revenues across the European Union – revenues that play a

  10. EU Competition Policy Since 1990

    DEFF Research Database (Denmark)

    Bartalevich, Dzmitry

    2013-01-01

    in anticartel enforcement policies, antimonopoly regulation, and the regulation of mergers and acquisitions. The purpose of this article is to fill the gap by attempting to link EU competition policy with U.S. antitrust, provide a critical overview of the most important elements of European competition policy......, and merger control....

  11. Zelfvoorzieningslandbouw op de EU-agenda

    NARCIS (Netherlands)

    Jongeneel, R.A.; Kerkhoffs, S.

    2005-01-01

    Het is onwaarschijnlijk dat de zelfvoorzieningslandbouw in de nieuwe lidstaten door de toetreding tot de EU snel zal verdwijnen. De duale sectorstructuur van de landbouw zadelt de EU met een nieuw probleem op. Dit vraagt om een meer gedifferentieerd landbouwbeleid.

  12. Rotating disk atomization of Gd and Gd-Y for hydrogen liquefaction via magnetocaloric cooling

    Energy Technology Data Exchange (ETDEWEB)

    Slinger, Tyler [Iowa State Univ., Ames, IA (United States)

    2016-12-17

    In order to enable liquid hydrogen fuel cell technologies for vehicles the cost of hydrogen liquefaction should be lowered. The current method of hydrogen liquefaction is the Claude cycle that has a figure of merit (FOM) of 0.3-0.35. New magnetocaloric hydrogen liquefaction devices have been proposed with a FOM>0.5, which is a significant improvement. A significant hurdle to realizing these devices is the synthesis of spherical rare earth based alloy powders of 200μm in diameter. In this study a centrifugal atomization method that used a rotating disk with a rotating oil quench bath was developed to make gadolinium and gadolinium-yttrium spheres. The composition of the spherical powders included pure Gd and Gd0.91Y0.09. The effect of atomization parameters, such as superheat, melt properties, disk shape, disk speed, and melt system materials and design, were investigated on the size distribution and morphology of the resulting spheres. The carbon, nitrogen, and oxygen impurity levels also were analyzed and compared with the magnetic performance of the alloys. The magnetic properties of the charge material as well as the resulting powders were measured using a vibrating sample magnetometer. The saturation magnetization and Curie temperature were the target properties for the resulting spheres. These values were compared with measurements taken on the charge material in order to investigate the effect of atomization processing on the alloys.

  13. The isothermal section (500 C) of the Gd-Cu-Ni ternary phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Huaiying [Guangxi Univ., Nanning (China). Mater. Sci. Inst.; Zhuang Yinghong [Guangxi Univ., Nanning (China). Mater. Sci. Inst.; Gu Zhengfei [Guilin Electrical Equipment Scientific Research Institute, Guilin (China)

    1995-04-15

    The isothermal section (500 C) of the Gd-Cu-Ni ([Gd]{<=}33.3 at.%) ternary phase diagram was determined using differential thermal analysis, optical microscopy, X-ray diffraction and electron microprobe techniques. This partial isothermal section consists of 12 single-phase regions, 24 two-phase regions and 12 three-phase regions. The 12 single-phase regions include one ternary compound (Gd(Cu{sub 1-x}Ni{sub x}){sub 3}, x=0.2-0.46), four Gd-Cu compounds (GdCu{sub 2}, Gd{sub 2}Cu{sub 9}, GdCu{sub 5}, GdCu{sub 6}), six Gd-Ni compounds (GdNi{sub 2}, GdNi{sub 3}, Gd{sub 2}Ni{sub 7}, GdNi{sub 4}, GdNi{sub 5}, Gd{sub 2}Ni{sub 17}) and the {alpha}-(Cu,Ni) solid solution. ((orig.))

  14. Defect Engineering by Codoping in KCaI3 :Eu2 + Single-Crystalline Scintillators

    Science.gov (United States)

    Wu, Yuntao; Li, Qi; Jones, Steven; Dun, Chaochao; Hu, Sheng; Zhuravleva, Mariya; Lindsey, Adam C.; Stand, Luis; Loyd, Matthew; Koschan, Merry; Auxier, John; Hall, Howard L.; Melcher, Charles L.

    2017-09-01

    Eu2 + -doped alkali or alkali earth iodide scintillators with energy resolutions ≤3 % at 662 keV promise the excellent discrimination ability for radioactive isotopes required for homeland-security and nuclear-nonproliferation applications. To extend their applications to x-ray imaging, such as computed tomography scans, the intense afterglow which delays the response time of such materials is an obstacle that needs to be overcome. However, a clear understanding of the origin of the afterglow and feasible solutions is still lacking. In this work, we present a combined experimental and theoretical investigation of the physical insights of codoping-based defect engineering which can reduce the afterglow effectively in KCaI3:Eu2 + single-crystal scintillators. We illustrate that Sc3 + codoping greatly suppresses the afterglow, whereas Y3 + , Gd3 + , or La3 + codoping enhances the afterglow. Meanwhile, a light yield of 57 000 photons / MeV and an energy resolution of 3.4% at 662 keV can be maintained with the appropriate concentration of Sc3 + codoping, which makes the material promising for medical-imaging applications. Through our thermoluminescence techniques and density-functional-theory calculations, we are able to identify the defect structures and understand the mechanism by which codoping affects the scintillation performance of KCaI3:Eu2 + crystals. The proposed defect-engineering strategy is further validated by achieving afterglow suppression in Mg2 + codoped KCaI3:Eu2 + single crystals.

  15. Redetermination of [EuCl2(H2O6]Cl

    Directory of Open Access Journals (Sweden)

    Frank Tambornino

    2014-06-01

    Full Text Available The crystal structure of the title compound, hexaaquadichloridoeuropium(III chloride, was redetermined with modern crystallographic methods. In comparison with the previous study [Lepert et al. (1983. Aust. J. Chem. 36, 477–482], it could be shown that the atomic coordinates of some O atoms had been confused and now were corrected. Moreover, it was possible to freely refine the positions of the H atoms and thus to improve the accurracy of the crystal structure. [EuCl2(H2O6]Cl crystallizes with the GdCl3·6H2O structure-type, exhibiting discrete [EuCl2(H2O6]+ cations as the main building blocks. The main blocks are linked with isolated chloride anions via O—H...Cl hydrogen bonds into a three-dimensional framework. The Eu3+ cation is located on a twofold rotation axis and is coordinated in the form of a Cl2O6 square antiprism. One chloride anion coordinates directly to Eu3+, whereas the other chloride anion, situated on a twofold rotation axis, is hydrogen bonded to six octahedrally arranged water molecules.

  16. Determination of the valence in Sm-based filled skutterudite compounds

    International Nuclear Information System (INIS)

    Mizumaki, M.; Tsutsui, S.; Tanida, H.; Uruga, T.; Kikuchi, D.; Sugawara, H.; Sato, H.

    2006-01-01

    We have measured XAS spectra at Sm L 3 -edge in four Sm-based filled skutterudite compounds. The only XAS spectrum of SmOs 4 Sb 12 around the Sm L 3 -edge exhibit a double peak structure that is the characteristic feature of the mixed valence system due to Sm 2+ and Sm 3+ states whereas those of others exhibit a single peak structure characteristic in Sm 3+ systems. The average valence of Sm ions in SmOs 4 Sb 12 was 2.83. We conclude that the presence of a non-magnetic Sm 2+ state correlates with the unusual heavy fermion state in SmOs 4 Sb 12

  17. Assessing EU perception in Kazakhstan's mass media

    Directory of Open Access Journals (Sweden)

    Bakyt Ospanova

    2017-01-01

    Our main findings suggest that Kazakhstan's mass media positively perceives the role of the EU in the region. Moreover, they tend to portray the EU mainly as an economic powerhouse. Our findings support some suggestions by similar studies of the EU's external perception.

  18. Brexit, the EU and the Middle East

    DEFF Research Database (Denmark)

    Seeberg, Peter

    2017-01-01

    Following the Brexit referendum the UK is leaving the EU and this means that the UK no longer stands together with the EU on the international scene. The British Prime Minister Theresa May has recently invoked the EU Treaty Article 50 initiating the Brexit process and obviously the UK leaders know...

  19. Magnetic properties of Sm5Fe17 melt-spun ribbons and their borides

    Directory of Open Access Journals (Sweden)

    Tetsuji Saito

    2015-10-01

    Full Text Available Sm5Fe17 melt-spun ribbons exhibited low coercivity and partly or mostly consisted of the amorphous phase. Annealing of Sm5Fe17 melt-spun ribbon resulted in the formation of the Sm5Fe17 phase. The annealed Sm5Fe17 melt-spun ribbon exhibited a high coercivity. It was found that the addition of B to the Sm5Fe17 alloy resulted in the promotion of the Sm2Fe14B phase. Annealed Sm5Fe17Bx (x = 0.5 melt-spun ribbons consisted of the Sm5Fe17 phase together with the Sm2Fe14B and SmFe2 phases. On the other hand, annealed Sm5Fe17Bx (x = 1.0-1.5 melt-spun ribbons consisted of the Sm2Fe14B and SmFe2 phases without the Sm5Fe17 phase. The resultant Sm5Fe17Bx (x = 1.0-1.5 melt-spun ribbons still showed a coercivity of around 2 kOe. The annealed Sm5Fe17 melt-spun ribbon exhibited a high coercivity over 25 kOe and a remanence of 40 emu/g, whereas the annealed Sm5Fe17B1.0 melt-spun ribbon exhibited a high remanence of 65 emu/g and a coercivity of 2.0 kOe.

  20. CCSDS SM and C Mission Operations Interoperability Prototype

    Science.gov (United States)

    Lucord, Steven A.

    2010-01-01

    This slide presentation reviews the prototype of the Spacecraft Monitor and Control (SM&C) Operations for interoperability among other space agencies. This particular prototype uses the German Space Agency (DLR) to test the ideas for interagency coordination.

  1. The simultaneous mass and energy evaporation (SM2E) model.

    Science.gov (United States)

    Choudhary, Rehan; Klauda, Jeffery B

    2016-01-01

    In this article, the Simultaneous Mass and Energy Evaporation (SM2E) model is presented. The SM2E model is based on theoretical models for mass and energy transfer. The theoretical models systematically under or over predicted at various flow conditions: laminar, transition, and turbulent. These models were harmonized with experimental measurements to eliminate systematic under or over predictions; a total of 113 measured evaporation rates were used. The SM2E model can be used to estimate evaporation rates for pure liquids as well as liquid mixtures at laminar, transition, and turbulent flow conditions. However, due to limited availability of evaporation data, the model has so far only been tested against data for pure liquids and binary mixtures. The model can take evaporative cooling into account and when the temperature of the evaporating liquid or liquid mixture is known (e.g., isothermal evaporation), the SM2E model reduces to a mass transfer-only model.

  2. Structural and physical properties of Sm 3 doped magnesium zinc ...

    Indian Academy of Sciences (India)

    Samarium (Sm 3 + ) doped magnesium zinc sulfophosphate glass system of composition ( 60 – x )P 2 O 5 –20MgO–20ZnSO 4 – x Sm 2 O 3 ( x = 0.0 , 0.5, 1.0, 1.5 and 2.0 mol%) were synthesized using melt-quenching technique. The structure and physical properties of prepared glass samples were characterized.

  3. EU Studies in Denmark and Sweden

    DEFF Research Database (Denmark)

    Garski, Salla; Jørgensen, Knud Erik; Manners, Ian

    2012-01-01

    In this brief chapter we take stock of Danish and Swedish scholarship on the European Union (EU). We intend to analyze and evaluate Danish and Swedish scholarship on EU issues, using a mixed methodology integrated into the analysis of this chapter. The method integrates a secondary analysis...... of leading literature by Garský; an extensive comparative bibliometric survey building on Manners (2007); and the comparative assessments of EU studies by Jørgensen and Manners based on their professional experiences of EU studies across Europe. The chapter points out controversies on research perspectives......, and suggests new EU research questions that collaborative projects could address....

  4. Synergistic effect of Al and Gd on enhancement of mechanical properties of magnesium alloys

    Directory of Open Access Journals (Sweden)

    Bita Pourbahari

    2017-04-01

    Full Text Available The effect of Gd/Al ratio on the properties of as-cast Mg-Gd-Al-Zn alloys was investigated by changing the chemical composition from that of AZ61 to GZ61. At the ratio of 1, the Al2Gd phase becomes predominant and Mg17Al12 is hardly seen in the microstructure. As a potent inoculant, the Al2Gd phase resulted in intense grain refinement and enhancement of strength, ductility and toughness. For instance, the tensile strength and elongation to failure of Mg-3Gd-3Al-1Zn alloy were enhanced by ~4% and 180% compared with those of AZ61 alloy, respectively. However, at high Gd/Al ratios, the Al2Gd phase was replaced by (Mg,Al3Gd and Mg5Gd phases and very large grain sizes were achieved, which led to poor tensile properties and the appearance of cleavage facets on the fracture surfaces. Therefore, it can be deduced that the presence of Gd and Al, in appropriate amounts to reach Gd/Al ratio of ~ 1, is required for the achievement of grain refinement, good ductility, high strength, and the appearance of ductile fracture surfaces in the Mg-Gd-Al-Zn system. Conclusively, the Mg-Gd-Al-Zn alloys can be considered as a new class of structural magnesium alloy and it is superior to both AZ (Mg-Al-Zn and GZ (Mg-Gd-Zn series of alloys.

  5. Electrochemical reduction of Eu (III) in propionic media

    International Nuclear Information System (INIS)

    Brotto, M.E.; Rabockai, T.

    1988-01-01

    Some chronopotentiometric studies of Eu (III) electro-reducion in propionic media that suggests the presence of two parallel rections: Eu (III) → Eu (II) and Eu (III) → Eu (II) → Y are presented. Some experimental data, such Eu (III) reducion, electrolysis of solutions and ionic power of the system are discussed. (M.J.C.) [pt

  6. EU Law and Multiple Discrimination

    DEFF Research Database (Denmark)

    Nielsen, Ruth

    2006-01-01

    In EU law, nationality and gender were the only equality issues on the legal agenda from the outset in 1958 and for about 40 years. Multiple discrimination was not addressed until the 1990's. The intersectionality approach which has been widely discussed outside Europe has mainly been used with a...... with a view to gendermainstreaming the fight against other kinds of discrimination (on grounds of ethnic origin, age, etc).......In EU law, nationality and gender were the only equality issues on the legal agenda from the outset in 1958 and for about 40 years. Multiple discrimination was not addressed until the 1990's. The intersectionality approach which has been widely discussed outside Europe has mainly been used...

  7. Menneskerettigheder og handelspolitik i EU

    DEFF Research Database (Denmark)

    Manners, Ian

    2012-01-01

    to food, the right heat, the right to have a job"; we still live with this division today. There have been a number of attempts over the last 10-15 years, who have tried to work around these problems. One of them is a movement within the UN are trying to reinterpret what it means to have 'development...... point for reaction against the liberalization of the global economy. It is extremely interesting. Again this demonstrates the complexity of EU policy. Some Member States were quite supportive of the WTO, while others expected the ILO to take the lead. See, for example, the declaration on "Core Labour...... is this contradiction "free and fair trade" in the same sentence becomes, in an attempt both economically and politically to get it to make sense within the EU. Ian Manners is a professor and works at Roskilde University, the Institute for society and globalization. His research is globalization and Europeanisation...

  8. EU focus on climate change

    International Nuclear Information System (INIS)

    2002-01-01

    Faced with the mounting evidence of the harmful effects of climate change, the European Union is convinced that the world must take urgent action to tackle the problem. That is why the EU has been at the forefront of international efforts to deal with climate change for well over a decade. The EU is convinced that the status quo is simply not an option. Without urgent, concerted action, the problem will continue to get worse with potentially disastrous consequences. That is why the European Union has consistently taken the lead in international moves to tackle climate change and why it will continue to develop this strategy for as long as it takes to guarantee a world for ourselves and our children where everyone can grow, breathe and live in safety

  9. Good Governance in the EU

    Directory of Open Access Journals (Sweden)

    Gina Livioara GOGA

    2009-10-01

    Full Text Available Considering the EU adhesion, good governance has been analyzed from different perspectives, in the judicial literature being an analytic model or a normative concept. Some authors have wondered if this concept is a fashion, comprising some older ideas and principles, while other authors have asserted that the reasons why different methods of governance appear in the EU are based on “the complexity and the uncertainty of the problems on the agenda, an irreducible, the new approaches on public administration and law, hidden competencies, legitimacy and subsidiarity”. At a normative level, the White Paper of European Governance consecrated five principles on which good governance is based upon: openness, participation, responsibility, efficiency and coherence.

  10. Polarized single crystal neutron diffraction study of the zero-magnetization ferromagnet Sm1 -xGdxAl2 (x =0.024 )

    Science.gov (United States)

    Chatterji, T.; Stunault, A.; Brown, P. J.

    2018-02-01

    We have determined the temperature evolution of the spin and orbital moments in the zero-magnetization ferromagnet Sm1 -xGdxAl2 (x = 0.024) by combining polarized and unpolarized single crystal neutron diffraction data. The sensitivity of the polarized neutron technique has allowed the moment values to be determined with a precision of ≈0.1 μB . Our results clearly demonstrate that, when magnetized by a field of 8 T, the spin and orbital moments in Sm1 -xGdxAl2 are oppositely directed, so that the net magnetization is very small. Below 60 K the contributions from spin and orbital motions are both about 2 μB , with that due to orbital motion being slightly larger than that due to spin. Between 60 and 65 K the contributions of each to the magnetization fall rapidly and change sign at Tcomp ≈67 K , above which the aligned moments recover but with the orbital magnetization still slightly higher than the spin one. These results imply that above Tcomp the small resultant magnetization of the Sm3 + ion is oppositely directed to the magnetizing field. It is suggested that this anomaly is due to polarization of conduction electron spin associated with the doping Gd3 + ions.

  11. Gd-HOPO Based High Relaxivity MRI Contrast Agents

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Ankona; Raymond, Kenneth

    2008-11-06

    Tris-bidentate HOPO-based ligands developed in our laboratory were designed to complement the coordination preferences of Gd{sup 3+}, especially its oxophilicity. The HOPO ligands provide a hexadentate coordination environment for Gd{sup 3+} in which all he donor atoms are oxygen. Because Gd{sup 3+} favors eight or nine coordination, this design provides two to three open sites for inner-sphere water molecules. These water molecules rapidly exchange with bulk solution, hence affecting the relaxation rates of bulk water olecules. The parameters affecting the efficiency of these contrast agents have been tuned to improve contrast while still maintaining a high thermodynamic stability for Gd{sup 3+} binding. The Gd- HOPO-based contrast agents surpass current commercially available agents ecause of a higher number of inner-sphere water molecules, rapid exchange of inner-sphere water molecules via an associative mechanism, and a long electronic relaxation time. The contrast enhancement provided by these agents is at least twice that of commercial contrast gents, which are based on polyaminocarboxylate ligands.

  12. Epi-thermal neutron diffraction of Gd alloy, (3)

    International Nuclear Information System (INIS)

    Watanabe, Noboru; Ishikawa, Yoshikazu; Sekine, Hisashi; Suzuki, Michio; Fujii, Hironobu.

    1975-01-01

    Epi-thermal neutron diffraction of Gd alloy was studied. A single crystal of GdZn was made by the Bridgman's method, and the degree of order was 1.00. One of the epi-thermal neutron diffraction patterns from the GdZn single crystal is shown. The nuclear scattering amplitude of Gd was obtained as bsub(Gd)=(1.15 +- 0.15) x 10 -12 cm, which is in good agreement with the value obtained from the comparison with the magnetic diffraction of Gdsub(0.9)Ysub(0.1). The epi-thermal neutron diffraction of Gdsub(0.85)Thsub(0.15) was also studied. The magnetic satellite line was clearly seen at low temperature. Higher order satellite line could not be observed. The magnetic structures in which the satellite is observed at are proper screw, cycloid, transverse sine wave and conical structures. The possibility of the conical structure was eliminated by the observed diffraction patterns at room temperature and at 80 0 K. The magnetic structure factors for the other three structures were obtained. At present, it is unable to determine the magnetic structure for Gdsub(0.85)Thsub(0.15). (Kato, T.)

  13. Large magnetocaloric effect of GdNiAl2 compound

    International Nuclear Information System (INIS)

    Dembele, S.N.; Ma, Z.; Shang, Y.F.; Fu, H.; Balfour, E.A.; Hadimani, R.L.; Jiles, D.C.; Teng, B.H.; Luo, Y.

    2015-01-01

    This paper presents the structure, magnetic properties, and magnetocaloric effect of the polycrystalline compound GdNiAl 2 . Powder X-ray diffraction (XRD) measurement and Rietveld refinement revealed that GdNiAl 2 alloy is CuMgAl 2 -type phase structure with about 1 wt% GdNi 2 Al 3 secondary phase. Magnetic measurements suggest that the compound is ferromagnetic and undergoes a second-order phase transition near 28 K. The maximum value of magnetic entropy change reaches 16.0 J/kg K for an applied magnetic field change of 0–50 kOe and the relative cooling power was 6.4×10 2 J/kg. It is a promising candidate as a magnetocaloric material working near liquid hydrogen temperature (~20 K) exhibiting large relative cooling power. - Highlights: • Preferred orientation with axis of [010] was found in the GdNiAl 2 compound. • The ΔS Mmax and the RCP are 16.0 J/kg K and 640 J/kg, respectively, for ΔH=50 kOe. • Relative low rare earth content in GdNiAl 2 comparing with other candidates

  14. EU Law and Multiple Discrimination

    DEFF Research Database (Denmark)

    Nielsen, Ruth

    2006-01-01

    In EU law, nationality and gender were the only equality issues on the legal agenda from the outset in 1958 and for about 40 years. Multiple discrimination was not addressed until the 1990's. The intersectionality approach which has been widely discussed outside Europe has mainly been used...... with a view to gendermainstreaming the fight against other kinds of discrimination (on grounds of ethnic origin, age, etc)....

  15. Macroeconomic Imbalances in the EU

    OpenAIRE

    Stefan Ederer; Peter Reschenhofer

    2013-01-01

    This paper aims to identify different growth patterns in the EU which led to the emergence of macroeconomic imbalances. It provides a detailed statistical picture of the evolution of various macroeconomic variables on the demand as well as on the supply side, before, in and after the financial and economic crisis of 2008/09. It investigates the causes and discusses various ’channels’ which led to macroeconomic imbalances by means of a descriptive analysis of the key determinants of macroecono...

  16. Remanent magnetization of amorphous La--Gd--Au alloys with high Gd content

    Energy Technology Data Exchange (ETDEWEB)

    Poon, S.J.; Durand, J.

    1977-04-01

    Results of bulk magnetic measurements are reported for splat-cooled amorphous alloys (La/sub 100-x/Gd/sub x/)/sub 80/Au/sub 20/ over the concentrated region between the dilute (x less than or equal to 1 at.%) and the ferromagnetic range (x > 70 at.%). For x less than or equal to 40 at.% alloys, low field susceptibility maxima occur at temperatures proportional to x, and the reduced remanent magnetization M/sub rs/(T)/x depends only on the reduced temperature T/x. Our results are analyzed in the spirit of a phenomenological model of uncompensated magnetic clouds. The interplay of the RKKY interaction and of the anisotropic dipolar forces is sufficient to account for the order of magnitude of the remanent magnetization for x less than or equal to 40 alloys.

  17. Electron paramagnetic resonance of Gd3+ in TlGdSe2

    International Nuclear Information System (INIS)

    Duczmal, M.; Mosiniewicz-Szablewska, E.; Pokrzywnicki, S.

    2003-01-01

    Electron paramagnetic resonance has been studied on the polycrystalline sample of the layer compound TlGdSe 2 . When the temperature is lowered from room temperature the linewidth reaches a shallow minimum near 60 K and then decreases rapidly below 15 K. From the two-dimensional molecular field model two exchange constants J 1 and J 2 with the nearest and next nearest neighbors were estimated. The calculated high-temperature limit of the linewidth (341 mT) is in fair agreement with the experimental value (314 mT). It may be slightly improved after taking into account the preferred orientation of the sample. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  18. 31 CFR 585.315 - Person in the FRY (S&M).

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Person in the FRY (S&M). 585.315... General Definitions § 585.315 Person in the FRY (S&M). The term person in the FRY (S&M) includes any... under the laws of any jurisdiction in the FRY (S&M). ...

  19. School version of ESTE EU

    International Nuclear Information System (INIS)

    Carny, P.; Suchon, D.; Chyly, M.; Smejkalova, E.; Fabova, V.

    2008-01-01

    ESTE EU is information system and software for radiological impacts assessment to the territory of the country in case of radiation accident inside/outside of the country .The program enables to model dispersion of radioactive clouds in small-scale and meso-scale. The system enables the user to estimate prediction of the source term (release to the atmosphere ) for any point of radiation/nuclear accident in Europe (for any point of the release, but especially for the sites of European power reactors ). The system enables to utilize results of real radiological monitoring in the process of source term estimation. Radiological impacts of release to the atmosphere are modelled and calculated across the Europe and displayed in the geographical information system (GIS). The school version of ESTE EU is intended for students of the universities which are interested in or could work in the field of emergency response, radiological and nuclear accidents, dispersion modelling, radiological impacts calculation and urgent or preventive protective measures implementation. The school version of ESTE EU is planned to be donated to specialized departments of faculties in Slovakia, Czech Republic, etc. System can be fully operated in Slovak, Czech or English language. (authors)

  20. School version of ESTE EU

    International Nuclear Information System (INIS)

    Carny, P.; Suchon, D.; Chyly, M.; Smejkalova, E.; Fabova, V.

    2009-01-01

    ESTE EU is information system and software for radiological impacts assessment to the territory of the country in case of radiation accident inside/outside of the country .The program enables to model dispersion of radioactive clouds in small-scale and meso-scale. The system enables the user to estimate prediction of the source term (release to the atmosphere ) for any point of radiation/nuclear accident in Europe (for any point of the release, but especially for the sites of European power reactors ). The system enables to utilize results of real radiological monitoring in the process of source term estimation. Radiological impacts of release to the atmosphere are modelled and calculated across the Europe and displayed in the geographical information system (GIS). The school version of ESTE EU is intended for students of the universities which are interested in or could work in the field of emergency response, radiological and nuclear accidents, dispersion modelling, radiological impacts calculation and urgent or preventive protective measures implementation. The school version of ESTE EU is planned to be donated to specialized departments of faculties in Slovakia, Czech Republic, etc. System can be fully operated in Slovak, Czech or English language. (authors)