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Sample records for sm gd tb

  1. Thermochemical properties of lanthanoid-iron-perovskite at high temperatures. [La, Nd, Sm, Eu, Gd, Tb, Dy

    Energy Technology Data Exchange (ETDEWEB)

    Katsura, T; Kitayama, K; Sugihara, T [Tokyo Inst. of Tech. (Japan). Faculty of Science; Kimizuka, N

    1975-06-01

    The standard Gibbs energy of formation of C/sup -/FeO/sub 3/(C/sup -/=La, Nd, Sm, Eu, Gd, Tb, and Dy) from metallic iron, C/sub 2//sup -/O/sub 3/, and oxygen has been determined at temperatures from 1473 to 1673 K. Based on the free-energy data, the heat of reaction and the entropy change resulting from the reaction have been calculated. The values of the heat of reaction of LaFeO/sub 3/, NdFeO/sub 3/, SmFeO/sub 3/, EuFeO/sub 3/, and GdFeO/sub 3/ (the first group) were identical, - 107 kcal/mol, at the present temperature interval. However, the values of the heat of reaction of TbFeO/sub 3/ and DyFeO/sub 3/ (the second group) decreased with an increase in the temperature. The entropy change of each reaction in the first group was constant, independent of the temperature, and each value decreased in the sequence from LaFeO/sub 3/ to GdFeO/sub 3/. The entropy change of the second group decreased with an increase in the temperature. The change of the standard Gibbs energy was intimately related to the ionic radii of C/sup -/-ions, and the relationship between the Gibbs energy and the tolerance factor has been clarified.

  2. 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

  3. 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.

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

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    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.

  5. 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......, an intermediate stage involving a RE2O(C2H5CO2)4 composition was evidenced in the case of the Eu- and Sm-propionates. For all compounds, further decomposition of RE2O2CO3 into the corresponding sesquioxides (RE2O3) is accompanied by the release of CO2. The thermal decomposition of Dy- and Tb-propionates occurs...

  6. 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.

  7. 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)

  8. Structural relative stabilities and pressure-induced phase transitions for lanthanide trihydrides REH{sub 3} (RE=Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu)

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    Kong Bo, E-mail: kong79@yeah.net [National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900 (China); College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Zhang Lin, E-mail: zhanglinbox@263.net [National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900 (China); Chen Xiangrong [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Zeng Tixian [College of Physics and Electronic Information, China West Normal University, Nanchong 637002 (China); Cai Lingcang [National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900 (China)

    2012-06-15

    The structures, structural relative stabilities, pressure-induced phase transitions, and equations of state for lanthanide trihydrides REH{sub 3} (RE=Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu) are systematically studied using ab initio calculations under a core state model (CSM). The obtained ground-state parameters, such as lattice constants and bulk modulus, agree well with the available data. Among the P6{sub 3}/mm, P3-bar c1, and P6{sub 3}cm structures, the P6{sub 3}cm structure is found to be the most stable structure for lanthanide trihydride via the comparison of the calculated total energies. With the help of Birch-Murnaghan equation of state, the structural transitions from hexagonal to cubic for REH{sub 3} (RE=Sm, Gd, Ho, Er, and Lu) under pressure are affirmed; especially, the similar behavior of REH{sub 3} (RE= Tb, Dy, and Tm) is reasonably predicted for the first time by this means. For the transitions, the repulsive interactions of H-H atoms may play an important role in terms of the analysis of the structures in the vicinity of the theoretical phase transition.

  9. Platinum triangles in the Pt/Al framework of the intermetallic REPt6Al3 (RE = Ce-Nd, Sm, Gd, Tb) series

    International Nuclear Information System (INIS)

    Eustermann, Fabian; Stegemann, Frank; Renner, Konstantin; Janka, Oliver

    2017-01-01

    The compounds of the REPt 6 Al 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 6 Al 3 : wR = 0.0432, 759 F 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 3 triangles, centering the cavities of a flat honeycomb RE layer that are arranged in a..ABCA ' B ' C ' .. sequence. The other layer consists of condensed hexagonal [Pt 6 Al 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 6 Al 3 : T C = 5.0(1) K; GdPt 6 Al 3 : T C = 7.3(1) K; TbPt 6 Al 3 : T N = 3.6(1) K]. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. 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)

  11. Rare earth elements in the Pacific and Atlantic Oceans. [Pr, Tb, Ho, Tm, Lu, La, Nd, Sm, Eu, Gd, Yb, Ce

    Energy Technology Data Exchange (ETDEWEB)

    Baar, H J.W. de; Bacon, M P; Brewer, P G; Bruland, K W

    1985-09-01

    The first profiles of Pr, Tb, Ho, Tm and Lu in the Pacific Ocean, as well as profiles of La, Ce, Nd, Sm, Eu, Gd and Yb are reported. Concentrations of REE (except Ce) in the deep water are two to three times higher than those observed in the deep Atlantic Ocean. Surface water concentrations are typically lower than in the Atlantic Ocean, especially for the heavier elements Ho,Tm,Yb and Lu. Cerium is strongly depleted in the Pacific water column, but less so in the oxygen minimum zone. The distribution of the REE group is consistent with two simultaneous processes: (1) cycling similar to that of opal and calcium carbonate, and (2) adsorptive scavenging by settling particles and possibly by uptake at ocean boundaries. However, the first process can probably not be sustained by the low REE contents of shells, unless additional adsorption on surfaces is invoked. The second process, adsorptive scavenging, largely controls the oceanic distribution and typical seawater pattern of the rare earths. (author).

  12. Photoluminescence and cathodoluminescence properties of Sr{sub 2}Gd{sub 8}Si{sub 6}O{sub 26}:RE{sup 3+}(RE{sup 3+}=Tb{sup 3+}or Sm{sup 3+}) phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Sk. Khaja [Department of Electronics and Radio Engineering, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Rao, Gattupalli Manikya [Department of Physics, College of Science and Technology, Andhra University, Visakhapatanam, Andhra Pradesh 53003 (India); Raju, G. Seeta Rama; Krishna Bharat, L. [Department of Electronics and Radio Engineering, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Subba Rao, P.S.V., E-mail: raopsvs@rediffmail.com [Department of Physics, College of Science and Technology, Andhra University, Visakhapatanam, Andhra Pradesh 53003 (India); Yu, Jae Su, E-mail: jsyu@khu.ac.kr [Department of Electronics and Radio Engineering, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of)

    2016-10-15

    Trivalent terbium (Tb{sup 3+}) or samarium (Sm{sup 3+}) ions individually activated green and orange emitting Sr{sub 2}Gd{sub 8}Si{sub 6}O{sub 26} (SGSO) phosphors were synthesized by a citrate sol–gel method. The X-ray diffraction patterns of SGSO:Tb{sup 3+} and SGSO:Sm{sup 3+} phosphors exhibited the characteristic diffraction peaks of oxyapatite in a hexagonal lattice structure. The photoluminescence (PL) properties at ultraviolet (UV) or near-UV excitation wavelengths were measured for Tb{sup 3+} or Sm{sup 3+} ions doped SGSO phosphors as a function of its respective concentration. The PL spectra of SGSO:Tb{sup 3+} phosphors revealed the characteristic emission peaks of both Gd{sup 3+} and Tb{sup 3+} ions which are associated with 4f–4f transitions under 274 nm of excitation wavelength. When the concentration of Tb{sup 3+} ions increased over 0.05 mol (5 mol%), the emission intensities of {sup 5}D{sub 3} transitions decreased due to the well-known cross-relaxation process. However, based on the intensities of {sup 5}D{sub 4} transitions, the optimum concentration of Tb{sup 3+} ions was found to be 0.05 mol. Under 404 nm of excitation wavelength, the SGSO:Sm{sup 3+} phosphors exhibited the characteristic orange emission at 600 nm due to the {sup 4}G{sub 5/2}→{sup 6}H{sub 7/2} electronic transition. The optimum concentration of SGSO:Sm{sup 3+} phosphors was found to be 0.02 mol. The decay curves of the optimized SGSO:Tb{sup 3+} and SGSO:Sm{sup 3+} phosphors were well fitted to single exponential functions and their lifetimes were calculated. Furthermore, the optimized phosphor samples showed good thermal stability. Likewise, cathodoluminescence properties were also studied for the optimized samples as a function of filament current and accelerating voltage. The Commission International de I-Eclairage chromaticity coordinates were calculated for the SGSO:Tb{sup 3+} and SGSO:Sm{sup 3+} phosphors.

  13. Ion-irradiation resistance of the orthorhombic Ln_2TiO_5 (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_2TiO_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_2TiO_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_2TiO_5 before sequential improvement from Eu to Dy_2TiO_5 with T_c's dropping from 974 K to 712 K. In addition, bulk Dy_2TiO_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_2TiO_5, Eu_2TiO_5 and Tb_2TiO_5. • Systematic in-situ ion-irradiation study of almost complete Ln_2TiO_5 series (Ln = lanthanides) with orthorhombic crystal structure type. • The first grazing incidence study of bulk irradiated Dy_2TiO_5 looking for irradiation induced phase transition.

  14. 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

  15. General synthesis and structural evolution of a layered family of Ln8(OH)20Cl4 x nH2O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y).

    Science.gov (United States)

    Geng, Fengxia; Matsushita, Yoshitaka; Ma, Renzhi; Xin, Hao; Tanaka, Masahiko; Izumi, Fujio; Iyi, Nobuo; Sasaki, Takayoshi

    2008-12-03

    The synthesis process and crystal structure evolution for a family of stoichiometric layered rare-earth hydroxides with general formula Ln(8)(OH)(20)Cl(4) x nH(2)O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y; n approximately 6-7) are described. Synthesis was accomplished through homogeneous precipitation of LnCl(3) x xH(2)O with hexamethylenetetramine to yield a single-phase product for Sm-Er and Y. Some minor coexisting phases were observed for Nd(3+) and Tm(3+), indicating a size limit for this layered series. Light lanthanides (Nd, Sm, Eu) crystallized into rectangular platelets, whereas platelets of heavy lanthanides from Gd tended to be of quasi-hexagonal morphology. Rietveld profile analysis revealed that all phases were isostructural in an orthorhombic layered structure featuring a positively charged layer, [Ln(8)(OH)(20)(H(2)O)(n)](4+), and interlayer charge-balancing Cl(-) ions. In-plane lattice parameters a and b decreased nearly linearly with a decrease in the rare-earth cation size. The interlamellar distance, c, was almost constant (approximately 8.70 A) for rare-earth elements Nd(3+), Sm(3+), and Eu(3+), but it suddenly decreased to approximately 8.45 A for Tb(3+), Dy(3+), Ho(3+), and Er(3+), which can be ascribed to two different degrees of hydration. Nd(3+) typically adopted a phase with high hydration, whereas a low-hydration phase was preferred for Tb(3+), Dy(3+), Ho(3+), Er(3+), and Tm(3+). Sm(3+), Eu(3+), and Gd(3+) samples were sensitive to humidity conditions because high- and low-hydration phases were interconvertible at a critical humidity of 10%, 20%, and 50%, respectively, as supported by both X-ray diffraction and gravimetry as a function of the relative humidity. In the phase conversion process, interlayer expansion or contraction of approximately 0.2 A also occurred as a possible consequence of absorption/desorption of H(2)O molecules. The hydration difference was also evidenced by refinement results. The number of coordinated water

  16. 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)

  17. Synthesis and characterization of La(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III) and Dy(III) complexes of 2-acetylfuran-2-thenoylhydrazone

    International Nuclear Information System (INIS)

    Singh, B.; Singh, Praveen K.

    1998-01-01

    The reaction of 2-acetylfuran-2-thenoylhydrazone(afth) with Ln(III) trichlorides yields complexes of the type [Ln(afth)Cl 2 (H 2 O)(EtOH)]Cl, [Ln(III) = La, Pr, Nd, Sm, Eu, Gd, Tb and Dy]. The complexes have been characterized by molar conductance, magnetic susceptibility and TGA and DTA measurements, magnetic susceptibility and TGA and DTA measurements, FAB mass, infrared, proton NMR, electronic absorption and emission spectra. The terbium complex is found to be monomer from the FAB mass spectrum. The IR and NMR spectra suggest neutral tridentate behaviour of the Schiff base. A coordination number seven is proposed around the metal ions. Emission spectra suggest C 3v , symmetry around the metal ion with capped octahedron geometry for the europium complex. (author)

  18. 1,3-thiazole as suitable antenna ligand for lanthanide photoluminescence in [LnCl{sub 3}(thz){sub 4}].0.5thz, Ln = Sm, Eu, Gd, Tb, Dy

    Energy Technology Data Exchange (ETDEWEB)

    Dannenbauer, Nicole; Mueller-Buschbaum, Klaus [Wuerzburg Univ. (Germany). Inst. for Inorganic Chemistry; Kuzmanoski, Ana; Feldmann, Claus [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. for Inorganic Chemistry

    2014-02-15

    The series of luminescent monomeric lanthanide thiazole complexes [LnCl{sub 3}(thz){sub 4}].0.5thz (Ln = Sm, Eu, Gd, Tb, Dy; thz = 1,3-thiazole) has been synthesised and characterised by powder and single-crystal X-ray diffraction, IR and photoluminescence spectroscopy, DTA/TG as well as elemental analysis. The colourless compounds exhibit photoluminescence in the visible region with varying quantum efficiencies up to QY = 48 % for [LnCl{sub 3}(thz){sub 4}].0.5thz. Both, the lanthanide ions as well as the thiazole ligand contribute to the luminescence. Excitation can be achieved via intra-4f transitions and by exciting the ligand, emission is observed mainly from the lanthanide ions again by 4f transitions. Thiazole can transfer energy to the lanthanide ions, which further feeds the lanthanide emission by an efficient antenna effect even at room temperature. The lanthanide ions show pentagonal-bipyramidal coordination by three chloride anions and four N atoms of 1,3-thiazole, which leads to a strong {sup 5}D{sub 0} → {sup 7}F{sub 4} transition for europium. Significant differences arise as compared to thiophene complexes because no sulphur atom is involved in the metal coordination, as the thiazole ligand is solely coordinated via its nitrogen function. (orig.)

  19. ARPES study of the evolution of band structure and charge density wave properties in RTe3 ( R=Y , La, Ce, Sm, Gd, Tb, and Dy)

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Zahid; Brouet, Veronique; Yang, Wanli; Zhou, Xingjiang; Hussain, Zahid; Moore, R.G.; He, R.; Lu, D. H.; Shen, Z.X.; Laverock, J.; Dugdale, S.B.; Ru, N.; Fisher, R.

    2008-01-16

    We present a detailed angle-resolved photoemission spectroscopy (ARPES) investigation of the RTe3 family, which sets this system as an ideal"textbook" example for the formation of a nesting driven charge density wave (CDW). This family indeed exhibits the full range of phenomena that can be associated to CDWinstabilities, from the opening of large gaps on the best nested parts of Fermi surface (up to 0.4 eV), to the existence of residual metallic pockets. ARPES is the best suited technique to characterize these features, thanks to its unique ability to resolve the electronic structure in k space. An additional advantage of RTe3 is that theband structure can be very accurately described by a simple two dimensional tight-binding (TB) model, which allows one to understand and easily reproduce many characteristics of the CDW. In this paper, we first establish the main features of the electronic structure by comparing our ARPES measurements with the linear muffin-tinorbital band calculations. We use this to define the validity and limits of the TB model. We then present a complete description of the CDW properties and of their strong evolution as a function of R. Using simple models, we are able to reproduce perfectly the evolution of gaps in k space, the evolution of the CDW wave vector with R, and the shape of the residual metallic pockets. Finally, we give an estimation of the CDWinteraction parameters and find that the change in the electronic density of states n (EF), due to lattice expansion when different R ions are inserted, has the correct order of magnitude to explain the evolution of the CDW properties.

  20. Nitrato-complexes of Y(III), La(III), Ce(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III) and Ho(III) with 2-(2'-pyridyl) benzimidazole

    International Nuclear Information System (INIS)

    Mishra, A.; Singh, M.P.; Singh, V.K.

    1982-01-01

    The nitrato-complexes, [Y(PyBzH) 2 (NO 3 ) 2 ]NO 3 .H 2 O and Nd, Sm, Gd, Tb, Dy, Ho ; n=1-3, m=0-0.5 ; PyBzh=2-(2 -pyridyl)benzimidazole] are formed on interaction of the ligand with metal nitrates in ethanol. The electrical conductance values (116-129 ohm -1 cm 2 mol -1 ) suggest 1:1 electrolyte-nature of the complexes. Magnetic moment values of Ce(2.53 B.M.), Pr(3.62 B.M.), Nd(3.52 B.M.), Sm(1.70 B.M.), Gd(8.06 B.M.), Tb(9.44 B.M.), Dy(10.56 B.M.) and Ho(10.51 B.M.) in the complexes confirm the terpositive state of the metals. Infrared evidences are obtained for the existance of both coordinated (C 2 v) and uncoordinated (D 3 h) nitrate groups. Electronic absorption spectra of Pr(III)-, Nd(III)-, Sm(III)-, Tb(III)-, Dy(III)- and Ho(III)-complexes have been analysed in the light of LSJ terms. (author)

  1. Nitrato-complexes of Y(III), La(III), Ce(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III) and Ho(III) with 2-(2'-pyridyl) benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, A; Singh, M P; Singh, V K

    1982-05-01

    The nitrato-complexes, (Y(PyBzH)/sub 2/(NO/sub 3/)/sub 2/)NO/sub 3/.H/sub 2/O and Nd, Sm, Gd, Tb, Dy, Ho ; n=1-3, m=0-0.5 ; PyBzh=2-(2 -pyridyl)benzimidazole) are formed on interaction of the ligand with metal nitrates in ethanol. The electrical conductance values (116-129 ohm/sup -1/cm/sup 2/mol/sup -1/) suggest 1:1 electrolyte-nature of the complexes. Magnetic moment values of Ce(2.53 B.M.), Pr(3.62 B.M.), Nd(3.52 B.M.), Sm(1.70 B.M.), Gd(8.06 B.M.), Tb(9.44 B.M.), Dy(10.56 B.M.) and Ho(10.51 B.M.) in the complexes confirm the positive state of the metals. Infrared evidences are obtained for the existance of both coordinated (C/sub 2/v) and uncoordinated (D/sub 3/h) nitrate groups. Electronic absorption spectra of Pr(III)-, Nd(III)-, Sm(III)-, Tb(III)-, Dy(III)- and Ho(III)-complexes have been analysed in the light of LSJ terms.

  2. Ternary gallides RE_4Rh_9Ga_5, RE_5Rh_1_2Ga_7 and RE_7Rh_1_8Ga_1_1 (RE=Y, La-Nd, Sm, Gd, Tb). Intergrowth structures with MgCu_2 and CaCu_5 related slabs

    International Nuclear Information System (INIS)

    Seidel, Stefan; Rodewald, Ute C.; Poettgen, Rainer; Janka, Oliver

    2017-01-01

    Fourteen ternary gallides RE_4Rh_9Ga_5, RE_5Rh_1_2Ga_7 and RE_7Rh_1_8Ga_1_1 (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_4Rh_9Ga_5, Ce_5Rh_1_2Ga_7, Ce_7Rh_1_8Ga_1_1, Nd_5Rh_1_0_._4_4_(_4_)Ga_8_._5_6_(_4_), Nd_4Rh_9Ga_5 and Gd_4Rh_9Ga_5 were refined from single crystal X-ray diffractometer data. The new gallides are the n=2, 3 and 5 members of the RE_2_+_n Rh_3_+_3_n Ga_1_+_2_n structure series in the Parthe intergrowth concept. The slabs of these intergrowth structures derive from the cubic Laves phase MgCu_2 (Mg_2Ni_3Si as ternary variant) and CaCu_5 (CeCo_3B_2 as ternary variant). Only the Nd_5Rh_1_0_._4_4_(_4_)Ga_8_._5_6_(_4_) crystal shows Rh/Ga mixing within the Laves type slabs. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y_4Rh_9Ga_5 and Curie-Weiss paramagnetism for Gd_4Rh_9Ga_5 and Tb_4Rh_9Ga_5. Low-temperature data show ferromagnetic ordering at T_C=78.1 (Gd_4Rh_9Ga_5) and 55.8 K (Tb_4Rh_9Ga_5).

  3. Solution growth of Tb doped Gd_2O_3 film

    International Nuclear Information System (INIS)

    Ghosh, M.; Pitale, S.; Desai, D.G.; Patra, G.D.; Sen, S.; Gadkari, S.C.

    2016-01-01

    Nanomaterials of Gd_2O_3 have proven applications in medical imaging and cancer therapy due to the presence of element Gd. Also Gd_2O_3 films have been grown by vapor phase method as well as self assembly in solution and studied as a high-k dielectric and efficient luminescence material. Here, we report a method to obtain Tb doped Gd_2O_3 film by solution growth method followed by suitable heat treatment. Uniform films of Tb doped Gadolinium hydroxycarbonate have been deposited on fused quartz substrates kept inside a solution containing gadolinium nitrate, terbium nitrate and Urea maintained at 90°C. Gadolinium hydroxy-carbonate films are then treated at 800°C for 2 hour to obtain Tb doped cubic Gd_2O_3 as confirmed by X-ray diffraction measurement. The photoluminescence spectra display characteristic Tb emission at 544 nm when excited at 285 nm. The lifetime of Tb emission is found to be of the order of few microseconds. (author)

  4. 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 ...

  5. The isothermal section at 500 deg. C of the Gd-Tb-Ga ternary system

    International Nuclear Information System (INIS)

    Li, J.Q.; Jian, Y.X.; Ao, W.Q.; Zhuang, Y.H.; He, W.

    2006-01-01

    Phase equilibria in the Gd-Tb-Ga ternary system at 500 deg. C were investigated by X-ray powder diffraction and differential scanning calorimetry. The binary compounds, Gd 5 Ga 3 , Gd 3 Ga 2 , GdGa, GdGa 2 , Tb 5 Ga 3 , TbGa, TbGa 2 and TbGa 3 have been confirmed at 500 deg. C. No ternary compound was found in this system. The isothermal section of this system at 500 deg. C was constructed. It is composed of 7 single-phase regions, 8 two-phase regions and 2 three-phase regions. Four ternary continuous solid solutions (Gd, Tb), (Gd, Tb) 5 Ga 3 , (Gd, Tb)Ga, (Gd, Tb)Ga 2 were formed in this isothermal section. The maximum solid solubilities of Ga in (Gd, Tb) at 500 deg. C is 5.0 at.%. The homogeneity range of (Gd, Tb)Ga 2 is from 20 to 33.3 at.% Ga in Gd-Ga side but limited in Tb-Ga side. The solid solubilities of Ga in the other phases cannot be detected. The Curie temperatures of the Gd 0.6 Tb 0.4-x Ga x alloys increase from 270 to 298 K as x increases from 0 to 0.03

  6. 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}).

  7. The 500 deg. C isothermal section of the Gd-Tb-Co ternary system

    International Nuclear Information System (INIS)

    Zhou, K.W.; Zhuang, Y.H.; Li, J.Q.; Zhu, Q.M.; Deng, J.Q.

    2006-01-01

    The isothermal section of the phase diagram of the Gd-Tb-Co ternary system at 500 deg. C was investigated by X-ray powder diffraction, differential thermal analysis and metallographic analysis techniques. In this isothermal section, there are nine single-phase regions, eight two-phase regions and none three-phase region. No ternary compound was found. The compounds Gd 2 Co 17 and Tb 2 Co 17 , Gd 2 Co 7 and Tb 2 Co 7 , GdCo 3 and TbCo 3 , GdCo 2 and TbCo 2 , Gd 4 Co 3 and Tb 4 Co 3 , Gd 12 Co 7 and Tb 12 Co 7 , Gd 3 Co and Tb 3 Co, Gd and Tb form a continuous series of solid solutions. In addition, we experimentally determined the vertical section of pseudobinary system and the Curie temperature of Gd 1-x Tb x Co 2 (x from 0 to 1) series alloys

  8. Ternary silicides ScIr{sub 4}Si{sub 2} and RERh{sub 4}Si{sub 2} (RE = Sc, Y, Tb-Lu) and quaternary derivatives RERh{sub 4}Si{sub 2-x}Sn{sub x} (RE = Y, Nd, Sm, Gd-Lu) - structure, chemical bonding, and solid state NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vosswinkel, Daniel; Benndorf, Christopher; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Sao Paulo Univ., Sao Carlos (Brazil). Inst. of Physics; Matar, Samir F. [Bordeaux Univ., CNRS, ICMCB, UPR 9048, Pessac (France)

    2016-11-01

    The silicides ScIr{sub 4}Si{sub 2} and RERh{sub 4}Si{sub 2} (RE = Sc, Y, Tb-Lu) and silicide stannides RERh{sub 4}Si{sub 2-x}Sn{sub x}(RE = Y, Nd, Sm, Gd-Lu) were synthesized from the elements by arc-melting and subsequent annealing. The new compounds crystallize with the orthorhombic YRh{sub 4}Ge{sub 2} type structure, space group Pnma. They were characterized by X-ray powder patterns and several structures were refined from single crystal X-ray diffractometer data. The main structural motifs of this series of silicides are tricapped trigonal prisms formed by the transition metal and rare earth atoms. One of the two crystallographically independent silicon sites allows for formation of solid solutions with tin, exemplarily studied for ErRh{sub 4}Si{sub 2-x}Sn{sub x}. Electronic structure calculations reveal strong covalent Rh-Si bonding as the main stability factor. Multinuclear ({sup 29}Si, {sup 45}Sc, and {sup 89}Y) magic-angle spinning (MAS) NMR spectra of the structure representatives with diamagnetic rare-earth elements (Sc, Y, Lu) are found to be consistent with the crystallographic data and specifically confirm the selective substitution of Sn in the Si2 sites in the quaternary compounds YRh{sub 4}SiSn and LuRh{sub 4}SiSn.

  9. Energy transfer phenomena and Judd-Ofelt analysis on Sm{sup 3+} ions in K{sub 2}GdF{sub 5} crystal

    Energy Technology Data Exchange (ETDEWEB)

    Do, Phan Van [Thuyloi University, 175 Tay Son, Dong da Dist, Hanoi (Viet Nam); Tuyen, Vu Phi, E-mail: vptuyen@gust-edu.vast.vn [Graduate University of Science and Technology - VAST, 18 Hoang quoc Viet, Hanoi (Viet Nam); DuyTan University, K7/25 QuangTrung, Danang (Viet Nam); Quang, Vu Xuan [DuyTan University, K7/25 QuangTrung, Danang (Viet Nam); Khaidukov, Nicholas M. [Kurnakov Institute of General and Inorganic Chemistry, Moscow (Russian Federation); TrongThanh, Nguyen [Institute of Materials Science - VAST, 18 Hoang quoc Viet, Hanoi (Viet Nam); Sengthong, Bounyavong [DuyTan University, K7/25 QuangTrung, Danang (Viet Nam); Huy, Bui The, E-mail: buithehuy.nt@gmail.com [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of)

    2016-11-15

    The Raman, absorption, luminescence spectra and lifetimes curves of Sm{sup 3+}-doped K{sub 2}GdF{sub 5}were measured. Based on the Judd-Ofelt analysis, the values of radiative transition probabilities, branching ratios, integrated emission cross-sections and radiative lifetimes of excited states of Sm{sup 3+} in K{sub 2}GdF{sub 5} crystal were calculated. The migration of excitation energy between the Gd{sup 3+} ions and the trapping processes of Gd{sup 3+} excitation energy by Sm{sup 3+} and Tb{sup 3+}ions in K{sub 2}GdF{sub 5} crystal are reported. The role of the overlapping between the broad, allowed absorption bands of the RE{sup 3+} ions and the narrow absorption lines {sup 6}I{sub J} and {sup 6}P{sub J} of Gd{sup 3+} ions on the trapping rates of the RE{sup 3+} was discussed. The energy transfer between the Sm{sup 3+} ions was studied by the decay measurement, which has been fitted by Inokuti-Hirayama energy transfer model and revealed that electric dipole–quadrupole interaction is responsible for the energy transfer process in Sm{sup 3+} ions doped K{sub 2}GdF{sub 5} crystal.

  10. 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)

  11. Solvothermal syntheses, crystal structures, and properties of lanthanide(III) thioarsenates [Ln(dien)2(μ-1κ,2κ2-AsS4)]n (Ln==Sm, Eu, Gd) and [Ln(dien)2(1κ2-AsS4)] (Ln==Tb, Dy, Ho)

    International Nuclear Information System (INIS)

    Wang, Fang; Tang, Chunying; Chen, Ruihong; Zhang, Yong; Jia, Dingxian

    2013-01-01

    Solvothermal reactions of Ln 2 O 3 , As and S in diethylenetriamine (dien) at 170 °C for 6 days afforded two structural types of lanthanide thioarsenates with the general formulae [Ln(dien) 2 (μ-1κ,2κ 2 -AsS 4 )] n [Ln=Sm(1), Eu(2), Gd(3)] and [Ln(dien) 2 (1κ 2 -AsS 4 )] [Ln=Tb(4), Dy(5), Ho(6)]. The Ln 2 O 3 oxides were converted to [Ln(dien) 2 ] 3+ complex units in the solvothermal reactions. The As atom binds four S atoms, forming a tetrahedral AsS 4 unit. In 1−3, the AsS 4 units interconnect the [Ln(dien) 2 ] 3+ cations via Ln−S bonds as tridentate μ-1κ,2κ 2 -AsS 4 bridging ligands, resulting in the neutral coordination polymers [Ln(dien) 2 (μ-1κ,2κ 2 -AsS 4 )] n (Ln1). In 4−6, the AsS 4 units coordinate with the Ln 3+ ion of [Ln(dien) 2 ] 3+ as 1κ 2 -AsS 4 chelating ligands to form neutral coordination compounds [Ln(dien) 2 (1κ 2 -AsS 4 )] (Ln2). The Ln 3+ ions are in nine- and eight-coordinated environments in Ln1 and Ln2, respectively. The formation of Ln1 and Ln2 is related with ionic size of the Ln 3+ ions. Optical absorption spectra showed that 1−6 have potential use as semiconductors with the band gaps in the range 2.18−3.21 eV. - Graphical abstract: Two types of Ln-thioarsenates [Ln(dien) 2 (μ-1κ,2κ 2 -AsS 4 )] n and [Ln(dien) 2 (1κ 2 -AsS 4 )] were prepared by solvothermal methods and the soft Lewis basic AsS 4 3– ligand to Ln(III) centers with polyamine co-ligand was obtained. Display Omitted - Highlights: • Lanthanide thioarsenates were prepared by solvothermal methods. • The soft Lewis basic AsS 4 ligand coordinate Ln 3+ ions with coexistence polyamine ligands. • Two structural types of Ln-thioarsenates with structural turnover at Tb were obtained along Ln series. • The Ln-thioarsenates are potential semiconductors with optical band gaps in the range 2.18−3.21 eV

  12. 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

  13. 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.

  14. 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 .

  15. 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.

  16. Mixing of the odd-parity excitations in Nd, Sm and Gd nuclei with 86 and 87 neutrons

    International Nuclear Information System (INIS)

    Hammaren, Esko.

    1978-08-01

    The low- and medium-spin structure of the four nuclei 148 Sm 86 , 147 Nd 87 , 149 Sm 87 and 151 Gd 87 has been investigated experimentally and theoretically. The low-spin states of 151 Gd were obtained in the EC and β + decay of 151 Tb. The proposed level scheme, based on gamma-gamma coincidence and conversion-electron measurements, contains several new energy levels, among them a 5/2 - state at 427 keV. Nanosecond lifetimes of the states in 147 Nd were studied using the reaction 146 Nd(d,pγ) 147 Nd with 10 MeV deuterons. The reactions sup(148,150)Nd( 3 He,xn) at Esup(3sub(He)) = 19 - 27 MeV were used to study excited states in the nuclei 148 Sm and 149 Sm. Gamma-ray excitation fuctions, angular and time distributions, gamma-gamma coincidences and conversion electrons were measured. The presence of the Z = 64 closed proton core is proposed to be important for the structure of the even and odd isotones considered. Calculations performed for 148 Sm using the interacting-boson-approximation model and related to the N = 82, Z = 64 and N = 82, Z = 50 cores are discussed. The properties of the negative-parity low-spin states of the N = 87 isotones are explained with an axial particle-plus-rotor model. The calculated B(M1) and B(E2) probabilities are compared with a compilation of experimental values. Most of the spectroscopic factors of 149 Sm are reproduced well in the calculation. The consequences of nonaxiality are discussed for the fsub(7/2)- and hsub(9/2)-based excitations. The standard Meyer-ter-Vehn model calculation indicates different asymmetries for the fsub(7/2) and hsub(9/2) shells. (author)

  17. Analysis of the magnetic anisotropy in SmCo5 and GdCo5

    International Nuclear Information System (INIS)

    Zhao, T.; Jin, H.; Groessinger, R.; Kou, X.; Kirchmayr, H.R.

    1991-01-01

    The temperature dependence of the magnetic anisotropy constant K 1 for SmCo 5 and GdCo 5 is well reproduced by calculations based on a single-ion model taking into account the anisotropies of the R--Co exchange interaction and the Co-sublattice magnetic moment. The anisotropy of the R--Co exchange interaction plays an important role in reproducing the experimental K 1 (T) for SmCo 5 and GdCo 5 . It is found that the absolute value of the second order crystalline electric field parameter A 0 2 in SmCo 5 decreases monotonically with increasing temperature

  18. Solvothermal syntheses, crystal structures, and properties of lanthanide(III) thioarsenates [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} (Ln==Sm, Eu, Gd) and [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] (Ln==Tb, Dy, Ho)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Fang; Tang, Chunying; Chen, Ruihong; Zhang, Yong; Jia, Dingxian, E-mail: jiadingxian@suda.edu.cn

    2013-10-15

    Solvothermal reactions of Ln{sub 2}O{sub 3}, As and S in diethylenetriamine (dien) at 170 °C for 6 days afforded two structural types of lanthanide thioarsenates with the general formulae [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} [Ln=Sm(1), Eu(2), Gd(3)] and [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] [Ln=Tb(4), Dy(5), Ho(6)]. The Ln{sub 2}O{sub 3} oxides were converted to [Ln(dien){sub 2}]{sup 3+} complex units in the solvothermal reactions. The As atom binds four S atoms, forming a tetrahedral AsS{sub 4} unit. In 1−3, the AsS{sub 4} units interconnect the [Ln(dien){sub 2}]{sup 3+} cations via Ln−S bonds as tridentate μ-1κ,2κ{sup 2}-AsS{sub 4} bridging ligands, resulting in the neutral coordination polymers [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} (Ln1). In 4−6, the AsS{sub 4} units coordinate with the Ln{sup 3+} ion of [Ln(dien){sub 2}]{sup 3+} as 1κ{sup 2}-AsS{sub 4} chelating ligands to form neutral coordination compounds [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] (Ln2). The Ln{sup 3+} ions are in nine- and eight-coordinated environments in Ln1 and Ln2, respectively. The formation of Ln1 and Ln2 is related with ionic size of the Ln{sup 3+} ions. Optical absorption spectra showed that 1−6 have potential use as semiconductors with the band gaps in the range 2.18−3.21 eV. - Graphical abstract: Two types of Ln-thioarsenates [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} and [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] were prepared by solvothermal methods and the soft Lewis basic AsS{sub 4}{sup 3–} ligand to Ln(III) centers with polyamine co-ligand was obtained. Display Omitted - Highlights: • Lanthanide thioarsenates were prepared by solvothermal methods. • The soft Lewis basic AsS{sub 4} ligand coordinate Ln{sup 3+} ions with coexistence polyamine ligands. • Two structural types of Ln-thioarsenates with structural turnover at Tb were obtained along Ln series. • The Ln-thioarsenates are potential semiconductors

  19. Neutron diffraction studies on GdB{sub 6} and TbB{sub 6} powders

    Energy Technology Data Exchange (ETDEWEB)

    Luca, S.E.; Amara, M.; Galera, R.M.; Givord, F.; Granovsky, S.; Isnard, O.; Beneu, B

    2004-07-15

    We report here the first powder neutron diffraction study of GdB{sub 6} and TbB{sub 6}. GdB{sub 6} and TbB{sub 6} order antiferromagnetically at 15 and 21 K, respectively. In both compounds the transition at T{sub N} is of the first order. Moreover GdB{sub 6} presents a second spontaneous magnetic transition at T{sup *}=8 K. The present study shows that, in both compounds, the magnetic propagation vectors belong to the <((1)/(4)) ((1)/(4)) ((1)/(2))> star and that the direction of the magnetic moment is perpendicular to the ((1)/(2)) component of the wave-vector in GdB{sub 6}, while in TbB{sub 6} the moment is parallel to it. The deduced low-temperature values of the magnetic moments agree with those of the respective rare-earth trivalent ions.

  20. Neutron diffraction studies on GdB6 and TbB6 powders

    International Nuclear Information System (INIS)

    Luca, S.E.; Amara, M.; Galera, R.M.; Givord, F.; Granovsky, S.; Isnard, O.; Beneu, B.

    2004-01-01

    We report here the first powder neutron diffraction study of GdB 6 and TbB 6 . GdB 6 and TbB 6 order antiferromagnetically at 15 and 21 K, respectively. In both compounds the transition at T N is of the first order. Moreover GdB 6 presents a second spontaneous magnetic transition at T * =8 K. The present study shows that, in both compounds, the magnetic propagation vectors belong to the star and that the direction of the magnetic moment is perpendicular to the ((1)/(2)) component of the wave-vector in GdB 6 , while in TbB 6 the moment is parallel to it. The deduced low-temperature values of the magnetic moments agree with those of the respective rare-earth trivalent ions

  1. 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...

  2. 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)

  3. The equilibrium diagram and some properties of alloys Gd5Sb3-Tb5Sb3 system

    International Nuclear Information System (INIS)

    Azizov, Yu.S.; Abulkhaev, V.D.; Ganiev, I.N.

    2001-01-01

    The purpose of present work is investigation equilibrium diagram of Gd 5 Sb 3 -Tb 5 Sb 3 system in total range of concentrations. Equilibrium diagram of Gd 5 Sb 3 -Tb 5 Sb 3 system investigated by methods of difference-thermal, roentgen-phase and metallographic analyses. For the first time on the base of difference-thermal, roentgen-phase and metallographic analyses was formed the equilibrium diagram of Gd 5 Sb 3 -Tb 5 Sb 3 system. Was determined the cristal-chemical parameters of solid solutions with general formula Gd x Tb 5 - x Sb 3

  4. Magnetic properties of the germanides RE3Pt4Ge6 (RE=Y, Pr, Nd, Sm, Gd-Dy)

    International Nuclear Information System (INIS)

    Eustermann, Fabian; Eilers-Rethwisch, Matthias; Renner, Konstantin; Hoffmann, Rolf-Dieter; Poettgen, Rainer; Janka, Oliver; Oldenburg Univ.

    2017-01-01

    The germanides RE 3 Pt 4 Ge 6 (RE=Y, Pr, Nd, Sm, Gd-Dy) have been synthesized by arc-melting of the elements followed by inductive annealing to improve the crystallinity and allow for structural order. The compounds have been studied by powder X-ray diffraction; additionally the structure of Y 3 Pt 4 Ge 6 has been refined from single-crystal X-ray diffractometer data. It exhibits a (3+1)D modulated structure, indicating isotypism with Ce 3 Pt 4 Ge 6 . The crystal structure can be described as an intergrowth between YIrGe 2 - and CaBe 2 Ge 2 -type slabs along [100]. Temperature-dependent magnetic susceptibility measurements showed Pauli paramagnetism for Y 3 Pt 4 Ge 6 and Curie-Weiss paramagnetism for Pr 3 Pt 4 Ge 6 and Nd 3 Pt 4 Ge 6 . Sm 3 Pt 4 Ge 6 exhibits van Vleck paramagnetism, while antiferromagnetic ordering at T N =8.1(1) K and T N =11.0(1) K is observed for Gd 3 Pt 4 Ge 6 and Tb 3 Pt 4 Ge 6 , respectively.

  5. Energy transfer mechanism from Gd3+ to Sm3+ in K3Gd(PO4)2:Sm3+ phosphor

    International Nuclear Information System (INIS)

    Gupta, Palvi; Bedyal, A K; Kumar, Vinay; Khajuria, Y; Sharma, Vishal; Ntwaeaborwa, O M; Swart, H C

    2015-01-01

    Undoped K 3 Gd(PO 4 ) 2 and trivalent samarium (0.5–2.5 mol%) doped K 3 Gd(PO 4 ) 2 phosphors were synthesized by the solid-state method. The phase formation, optical and luminescence properties were investigated by x-ray diffraction (XRD), diffuse reflectance (DR) spectroscopy, and photoluminescence (PL) spectroscopy. The fluorescence decay spectra of the obtained phosphors were also recorded to study the energy transfer from sensitizer (Gd 3+ ) to activator (Sm 3+ ). Energy transfer effects from sensitizer to activator caused by rare-earth ions were mainly observed in the obtained PL and lifetime spectra. The decay curves of K 3 Gd(PO 4 ) 2 phosphor with different Sm 3+ ions concentrations were found to be non-exponential and the data is well fitted with the Inokuti–Hirayama (I–H) model. The energy transfer parameters such as critical distance for the transfer processes were determined. The Commission Internationale de l’Eclairage (CIE) chromatic coordinates and color-correlated temperature were also determined for the prepared phosphor. (paper)

  6. Cross Section Measurements for Some Elements Suited as Thermal Spectrum indicators: Cd, Sm, Gd and Lu

    Energy Technology Data Exchange (ETDEWEB)

    Sokolowski, E; Pekarek, H; Jonsson, E

    1964-05-15

    The effective cross sections of Cd, Sm, Gd and Lu have been measured by the oscillator technique in the spectrum of the central channel of the Swedish reactor R1. For Cd, Sm and Gd the 2200 m/s cross sections were deduced on the basis of Westcott's g and s factors. The values obtained were generally in agreement with other recent values obtained by integral methods, although a systematic trend indicated that the value T{sub n} - T{sub m} = 29 {+-} 10 deg C for the neutron spectrum, measured with a fast chopper, was slightly too high. A new value of T{sub n} - T{sub m} = 22.5 {+-} 3.5 deg C was deduced and new 2200 m/s cross sections were obtained by iteration. For natural Lu, the energy dependence of the cross section is not well known. Certain assumptions about the cross section function led to unreasonably high values for the 2200 m/s cross section. Complementary differential measurements of the cross sections of Cd, Sm and Gd were made with the Rl fast chopper. For Cd and Sm the 2200 m/s cross section thus obtained agreed within experimental error with those obtained from the integral measurements. For Gd, the chopper measured value was higher, confirming earlier findings and indicating that the Westcott g factor for Gd is too high. Cd: Integral meas. : {sigma}(2200) = 2,390 {+-} 45 b; Differential meas. : {sigma}(2200) = 2,445 {+-} 25 b; Sm: Integral meas. : {sigma}(2200) = 5,880 {+-} 90 b; Differential meas. : {sigma}(2200) = 5,740 {+-} 150 b; Gd: Integral meas. : {sigma}(2200) = 46,470 {+-} 550 b; Differential meas. : {sigma}(2200) = 47,900 {+-} 700 b.

  7. Cross Section Measurements for Some Elements Suited as Thermal Spectrum indicators: Cd, Sm, Gd and Lu

    Energy Technology Data Exchange (ETDEWEB)

    Sokolowski, E.; Pekarek, H.; Jonsson, E.

    1964-05-15

    The effective cross sections of Cd, Sm, Gd and Lu have been measured by the oscillator technique in the spectrum of the central channel of the Swedish reactor R1. For Cd, Sm and Gd the 2200 m/s cross sections were deduced on the basis of Westcott's g and s factors. The values obtained were generally in agreement with other recent values obtained by integral methods, although a systematic trend indicated that the value T{sub n} - T{sub m} = 29 {+-} 10 deg C for the neutron spectrum, measured with a fast chopper, was slightly too high. A new value of T{sub n} - T{sub m} = 22.5 {+-} 3.5 deg C was deduced and new 2200 m/s cross sections were obtained by iteration. For natural Lu, the energy dependence of the cross section is not well known. Certain assumptions about the cross section function led to unreasonably high values for the 2200 m/s cross section. Complementary differential measurements of the cross sections of Cd, Sm and Gd were made with the Rl fast chopper. For Cd and Sm the 2200 m/s cross section thus obtained agreed within experimental error with those obtained from the integral measurements. For Gd, the chopper measured value was higher, confirming earlier findings and indicating that the Westcott g factor for Gd is too high. Cd: Integral meas. : {sigma}(2200) = 2,390 {+-} 45 b; Differential meas. : {sigma}(2200) = 2,445 {+-} 25 b; Sm: Integral meas. : {sigma}(2200) = 5,880 {+-} 90 b; Differential meas. : {sigma}(2200) = 5,740 {+-} 150 b; Gd: Integral meas. : {sigma}(2200) = 46,470 {+-} 550 b; Differential meas. : {sigma}(2200) = 47,900 {+-} 700 b.

  8. Luminescence and energy transfer studies on Sm3+/Tb3+codoped telluroborate glasses for WLED applications

    Science.gov (United States)

    Uma, V.; Vijayakumar, M.; Marimuthu, K.; Muralidharan, G.

    2018-01-01

    A new series of Sm3+/Tb3+ codoped telluroborate glasses have been prepared by conventional melt quenching technique with the chemical composition (40-x-y)B2O3+15TeO2+15Li2O+15LiF+15NaF+xTb2O3+ySm2O3 (where x = 0, 0.5; y = 0, 0.05, 0.1, 0.25, 0.5, 1 and 2 wt%). The structural and optical behaviour of the prepared glasses were investigated through Fourier transform infrared spectroscopy (FTIR), optical absorption, photoluminescence and lifetime measurements. The fundamental vibrational units of the borate and tellurite network have been identified through FTIR spectra. Nephelauxetic ratio (βbar) and bonding parameter (δ) values indicate that the Smsbnd O bonds are ionic in nature. The characteristic emissions of terbium (543 nm, green) and samarium (645 nm, orange-red) were observed while exciting the Tb3+ ions. Higher magnitude of asymmetric intensity ratio (AIR) values confirms the higher asymmetry around the Sm3+ ion site. Decay profiles of Tb3+ ions (5D4 state) and Sm3+ ions (4G9/2 state) exhibit double exponential nature. The nature of interaction between the donor (Tb3+) and acceptor (Sm3+) has been analyzed through Inokuti-Hirayama (IH) model. Energy transfer from Tb3+ to Sm3+ ions is dominated by dipole-dipole type interaction. TBLT0.5S glass possess the better colour coordinates (0.41, 0.45) and colour correlated temperature (CCT) value (3524 K) and the same is suggested for eye safe warm white light emitting applications.

  9. The N=82 gap in /sup 146/Gd from beta -decay studies of Tb isotopes

    CERN Document Server

    Styczen, J; Kleinheinz, P; Piiparinen, M

    1981-01-01

    The beta -decay study of 23 s /sup 146/Tb suggests a ( pi h/sub 11/2/ nu d/sup -1//sub 3/2/) 5/sup -/ configuration for this activity. In its decay the authors have identified a pi h/sub 11/2/ to nu h/sub 9/2 / GT decay branch which populates neutron particle-hole states in /sup 146/Gd. Hence the N=82 single particle energy gap is less than 4 MeV. Neutron one-particle two-hole and two-particle one-hole states in /sup 145/Gd and /sup 147/Gd were identified in the beta -decays of 29 s /sup 145/Tb and 1.6 h /sup 147/Tb. (11 refs).

  10. High-speed magnetization reversal near the compensation temperature of amorphous GdTbFe

    International Nuclear Information System (INIS)

    Aeschlimann, M.; Vaterlaus, A.; Lutz, M.; Stampanoni, M.; Meier, F.; Siegmann, H.C.; Klahn, S.; Hansen, P.

    1991-01-01

    Using spin-polarized photoemission with a pulsed laser as light source, it is shown that the time for a thermally induced magnetization reversal depends critically on the temperature of the sample. For amorphous GdTbFe the time is shorter (longer) than the duration of the 16 ns laser pulses if the initial temperature is below (above) the compensation temperature

  11. Thermoelectric power of RFeAsO (R = Ce, Pr, Nd, Sm and Gd)

    International Nuclear Information System (INIS)

    Poddar, Asok; Mukherjee, Sanjoy; Samanta, Tanmay; Saha, Rajat S.; Mukherjee, Rajarshi; Dasgupta, Papri; Mazumdar, Chandan; Ranganathan, R.

    2009-01-01

    Thermoelectric powers of a series of compounds RFeAsO (R = Ce, Pr, Nd, Sm and Gd) have been reported for temperatures ranging from 77 K up to room temperature. The behavior of S(T) in this temperature range can be divided into three regions. Every region has been fitted with mathematical functions of T. The physical significance of separate terms in the mathematical functions has been discussed. Some kind of universality has been observed between different members of the series.

  12. Thermoelectric power of RFeAsO (R = Ce, Pr, Nd, Sm and Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Poddar, Asok, E-mail: asok.poddar@saha.ac.i [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, West Bengal (India); Mukherjee, Sanjoy [Department of Physics, The University of Burdwan, Golapbag, Burdwan 713 104, West Bengal (India); Samanta, Tanmay [Rishra High School, 15 Tilakram Dan Ghat Lane, Rishra, Hooghly, West Bengal (India); Saha, Rajat S.; Mukherjee, Rajarshi [Department of Physics, University of Burdwan, Golapbag, Burdwan 713 104, West Bengal (India); Dasgupta, Papri; Mazumdar, Chandan; Ranganathan, R. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, West Bengal (India)

    2009-07-15

    Thermoelectric powers of a series of compounds RFeAsO (R = Ce, Pr, Nd, Sm and Gd) have been reported for temperatures ranging from 77 K up to room temperature. The behavior of S(T) in this temperature range can be divided into three regions. Every region has been fitted with mathematical functions of T. The physical significance of separate terms in the mathematical functions has been discussed. Some kind of universality has been observed between different members of the series.

  13. A comparative study on the luminescence properties of Ce3+/Tb3+ doped Gd-based host nanomaterials

    Science.gov (United States)

    Jadhao, Charushila Vasant; Rani, Barkha; Sahu, Niroj Kumar

    2018-04-01

    A comparative study on the crystal phases and their respective luminescence behaviour of Gd3+ based host materials such as GdPO4, GdF3, GdVO4 and Gd2O3 sensitized with 7at.% Ce3+ and activated with 5 at.% Tb3+ have been reported. The nanomaterials were prepared by polyol method using ethylene glycol as solvent and found to have different crystal structures such as monoclinic, orthorhombic, tetragonal and cubic phase. Clear characteristics emission from Tb3+ has been observed in all the samples when excited in the absorption wavelength of Ce3+ and Gd3+ (˜280 nm). Among all the above materials, intense emission of Tb3+ is found in GdPO4 followed by GdF3, Gd2O3 and GdVO4 respectively. The Tb3+ emission is strongly influenced by the energy transfer process and crystal structure of the host materials and hence this study will be important for choosing suitable materials for display devices and biomedical applications.

  14. Photoluminescence and thermoluminescence properties of Tb3+ doped K3Gd(PO4)2 nanophosphor

    International Nuclear Information System (INIS)

    Gupta, Palvi; Bedyal, A.K.; Kumar, Vinay; Khajuria, Y.; Lochab, S.P.; Pitale, S.S.; Ntwaeaborwa, O.M.; Swart, H.C.

    2014-01-01

    Energy level diagram of Tb 3+ ion in the K 3 Gd(PO 4 ) 2 host lattice. - Highlights: • First time, a detailed TL and PL study on undoped and Tb 3+ doped K 3 Gd(PO 4 ) 2 nanophosphor. • Combustion method was employed to synthesize the Tb 3+ doped K 3 Gd(PO 4 ) 2 nanophosphor. • Mechanism of excitation and emission in undoped and Tb 3+ doped K 3 Gd(PO 4 ) 2 nanophosphor was given. - Abstract: Tb 3+ doped nanoparticulate K 3 Gd(PO 4 ) 2 phosphor was prepared by combustion method using urea as a fuel. The structure, optical and luminescent properties of the phosphor were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and thermoluminescence (TL) spectroscopy. In undoped K 3 Gd(PO 4 ) 2 , the excitation and emission peaks at 273 nm and 323 nm belongs to the 8 S 7/2 → 6 I J(J=7/2) and 6 P J(J=7/2) → 8 S 7/2 transitions of Gd 3+ while green emission was observed in the Tb 3+ doped K 3 Gd(PO 4 ) 2 . TL study was carried out after exposing the samples to γ-radiations (0.1–5 kGy) in the K 3 Gd(PO 4 ) 2 :Tb 3+ (1.5 mol%). The calculated kinetic parameters were compared with different methods. The band gap of the phosphor was estimated as 5.80 eV. The green shade of the Tb 3+ ion with the CIE coordinates (x, y) as (0.29, 0.54) was in good agreement with the well known green phosphors

  15. Laser-plasma source parameters for Kr, Gd, and Tb ions at 6.6 nm

    Energy Technology Data Exchange (ETDEWEB)

    Masnavi, Majid; Szilagyi, John; Parchamy, Homaira; Richardson, Martin C. [The Townes Laser Institute, College of Optics and Photonics, University of Central Florida, 4000 Central Florida Blvd., Orlando, Florida 32816 (United States)

    2013-04-22

    There is increasing interest in extreme-ultraviolet (EUV) laser-based lamps for sub-10-nm lithography operating in the region of 6.6 nm. A collisional-radiative model is developed as a post-processor of a hydrodynamic code to investigate emission from resonance lines in Kr, Gd, and Tb ions under conditions typical for mass-limited EUV sources. The analysis reveals that maximum conversion efficiencies of Kr occur at 5 Multiplication-Sign 10{sup 10}W/cm{sup 2}, while for Gd and Tb it was Asymptotically-Equal-To 0.9%/2{pi}sr for laser intensities of (2-5) Multiplication-Sign 10{sup 12}W/cm{sup 2}.

  16. Electrical characteristics of hybrid detector based Gd2O2S:Tb-Selenium for digital radiation imaging

    International Nuclear Information System (INIS)

    Kang, Sang-Sik; Park, Ji-Koon; Choi, Jang-Yong; Cha, Byung-Yul; Cho, Sung-Ho; Nam, Sang-Hee

    2005-01-01

    Fine Gd 2 O 2 S:Tb powders were synthesized by using a solution-combustion method for a high-resolution digital X-ray imaging detector. The PL spectrum showed that the phosphor was fully crystallized and that the Tb 3+ ions substituted well for the Gd 3+ sites. To investigate the X-ray response of the phosphor, a uniform Gd 2 O 2 S:Tb film was grown using a screen-printing method. The X-ray sensitivities of the 100 μm-Gd 2 O 2 S:Tb/30 μm -Se and 200 μm -Se detector were 470 and 420 pC/cm 2 /mR, respectively, at an electric field of 10 V/μm. The results of the study suggest that the hybrid detector has a significant potential in the application of digital radiography and fluoroscopy systems

  17. Perpendicular exchange coupling effects in ferrimagnetic TbFeCo/GdFeCo hard/soft structures

    Science.gov (United States)

    Wang, Ke; Wang, Yahong; Ling, Fujin; Xu, Zhan

    2018-04-01

    Bilayers consisting of magnetically hard TbFeCo and soft GdFeCo alloy were fabricated. Exchange-spring and sharp switching in a step-by-step fashion were observed in the TbFeCo/GdFeCo hard/soft bilayers with increasing GdFeCo thickness. A perpendicular exchange bias field of several hundred Oersteds is observed from the shift of minor loops pinned by TbFeCo layer. The perpendicular exchange energy is derived to be in the range of 0.18-0.30 erg/cm2. The exchange energy is shown to increase with the thickness of GdFeCo layer in the bilayers, which can be attributed to the enhanced perpendicular anisotropy of GdFeCo layer in our experimental range.

  18. 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.

  19. Molecular electrophosphorescence in (Sm, Gd)-β-diketonate complex blend for OLED applications

    International Nuclear Information System (INIS)

    Reyes, R.; Cremona, M.; Teotonio, E.E.S.; Brito, H.F.; Malta, O.L.

    2013-01-01

    In this work the preparation and characterization of the triple-layer organic light-emitting diode (OLED) using a mixture of the samarium and gadolinium β-diketonate complexes [Sm 0.5 Gd 0.5 (TTA) 3 (TPPO) 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 3 ) as electron transporting layer. The electroluminescence spectrum present emission narrow bands from the 4 G 5/2 → 6 H J transitions (where J=5/2, 7/2 and 9/2) characteristic of the Sm 3+ ion. These sharp lines are overlapped with a broad band attributed to the electrophosphorescence from the T 1 →S 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: ► Samarium and gadolinium complexes. ► OLED with complex blend (Sm,Gd). ► Electrophosphorescence emission detection. ► Application in OLED changing the color emission.

  20. Blue and green emitting Ce3+ and Tb3+ codoped Gd2O3 nanophosphors

    International Nuclear Information System (INIS)

    Loitongbam, Romeo Singh; Singh, W. Rameshwor

    2013-01-01

    Tb 3+ doped Gd 2 O 3 nanoparticles of 4-10 nm in size were synthesized from nitrate precursors by urea hydrolysis method in ethylene glycol medium at low temperature of 140 ℃. Characteristic Tb 3+ ion green emission corresponding to 5 D 4 ’! 7 F J was observed to be very strong, which further increases with heat treatment temperature. Characteristic blue color emission of Ce 3+ ion transitions for 5 d’! 2 F 7/2 and 2 F 5/2 (at 422 nm and 485 nm respectively) was found to be very strong in as-synthesized Ce 0.06 Tb 0.14 Gd 0.8 O 3 nanoparticles. However, its luminescence intensity decreases with increase in heating temperature or increase in the particle size/crystallinity, whereas there was a weak emission peak of Tb 3+ ion at 545 nm. The polycrystalline nature of as-prepared sample change to highly crystalline state when heated at elevated temperature (900 ℃). (author)

  1. Brillouin scattering on TbAsO4 and GdVO4

    International Nuclear Information System (INIS)

    Wehrle, H.

    1975-01-01

    Using a two-pass interferometer the set of elastic constants in TbAsO 4 was determined. On the basis of these constants the Debye temperature was evaluated for T→0. The crystallographic phase transition could not be demonstrated in either case (TbAsO 4 and TmAsO 4 ) because of small Brillouin-line intensity in the low-temperature region. The frequency shifts of the Brillouin lines detected in the case of GdVO 4 show an increase of 5% for the temperature change from room temperature to helium temperature. Assuming this dependence for TbAsO 4 , too, the Debye temperature is changed by 5%. (HPOE) [de

  2. 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

  3. 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.

  4. Synthesis and photoluminescence properties of GdBO3:Ln3+ (Ln = Eu, Tb) nanofibers by electrospinning

    International Nuclear Information System (INIS)

    Shen, Hongzhi; Feng, Shuo; Wang, Ying; Gu, Yipeng; Zhou, Jing; Yang, Hang; Feng, Guanlin; Li, Liang; Wang, Wenquan; Liu, Xiaoyang; Xu, Dapeng

    2013-01-01

    Highlights: ► GdBO 3 :Ln 3+ nanofibers were synthesized successfully by electrospinning. ► The samples have the average diameter of 150 nm and the flexible morphology. ► The GdBO 3 : Eu 3+ nanofibers have the stronger orange emission. ► The luminescence properties are different from the reported bulk material. ► We describe the energy transform process of GdBO 3 :Ln 3+ system. - Abstract: GdBO 3 :Ln 3+ (Ln = Eu, Tb) nanofibers were synthesized using electrospinning combined with heat treatment. The synthesized nanofibers were characterized by X-ray diffraction, Raman spectroscopy, field emission-scanning electron microscopy, thermogravimetric and differential thermal analyses, and photoluminescence. The experimental results show that the flexible synthesized nanofibers have an average diameter of approximately 150 nm. The nanofibers consist of crystalline grains with diameters of about 40 nm and have a vaterite-type structure of GdBO 3 . The GdBO 3 :Eu 3+ nanofibers exhibit strong orange and weak red emissions with a low ratio of red to orange emission intensities, which is different from those of the reported bulk materials and nanoparticles. The luminescence properties of the synthesized GdBO 3 :Tb 3+ nanofibers are essentially consistent with those of the synthesized GdBO 3 :Tb 3+ powders by solid-state reaction.

  5. Magnetic properties of the filled skutterudite-type structure compounds GdRu4P12 and TbRu4P12 synthesized under high pressure

    OpenAIRE

    Sekine, C; Uchiumi, T; Shirotani, I; Matsuhira, kazuyuki; Sakakibara, T; Goto, T; Yagi, T

    2000-01-01

    We have succeeded in synthesizing filled skutterudite-type structure compounds GdRu4P12 and TbRu4P12 under high pressure. The magnetic properties of GdRu4P12 and TbRu4P12 have been studied by means of electrical resistivity, magnetic susceptibility, and magnetization measurements. Magnetic experiments suggest that the Gd and Tb ions in the compounds have trivalent state. The compound GdRu4P12 displays features that suggest the occurrence of antiferromagnetic ordering below TN=22 K. In TbRu4P1...

  6. Electronic and Spectral Properties of RRhSn (R = Gd, Tb) Intermetallic Compounds

    Science.gov (United States)

    Knyazev, Yu. V.; Lukoyanov, A. V.; Kuz'min, Yu. I.; Gupta, S.; Suresh, K. G.

    2018-02-01

    The investigations of electronic structure and optical properties of GdRhSn and TbRhSn were carried out. The calculations of band spectrum, taking into account the spin polarization, were performed in a local electron density approximation with a correction for strong correlation effects in 4f shell of rare earth metal (LSDA + U method). The optical studies were done by ellipsometry in a wide range of wavelengths, and the set of spectral and electronic characteristics was determined. It was shown that optical absorption in a region of interband transitions has a satisfactory explanation within a scope of calculations of density of electronic states carried out.

  7. Ferromagnetic and paramagnetic magnetization of implanted GaN:Ho,Tb,Sm,Tm films

    Energy Technology Data Exchange (ETDEWEB)

    Maryško, M., E-mail: marysko@fzu.cz; Hejtmánek, J.; Laguta, V. [Institute of Physics of ASCR v.v.i., Cukrovarnická 10, 162 00 Prague 6 (Czech Republic); Sofer, Z.; Sedmidubský, D.; Šimek, P.; Veselý, M. [Department of Inorganic Chemistry, Institute of Chemical Technology, 166 28 Prague 6 (Czech Republic); Mikulics, M. [Peter Grünberg Institut, PGI-9, Forschung Centrum, Jülich D-52425 (Germany); JARA, Fundamentals of Future Information Technology, D52425 Jülich (Germany); Buchal, C. [Peter Grünberg Institut, PGI-9, Forschung Centrum, Jülich D-52425 (Germany); Macková, A.; Malínský, P. [Nuclear Physics Institute of the ASCR v.v.i., 250 68 Řež (Czech Republic); Department of Physics, Faculty of Science, J.E.Purkinje University, České mládeže, 400 96 Ústí nad Labem (Czech Republic); Wilhelm, R. A. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Dresden (Germany); Technische Universität Dresden, 01062 Dresden (Germany)

    2015-05-07

    The SQUID magnetic measurements were performed on the GaN films prepared by metal-organic vapour phase epitaxy and implanted by Tb{sup 3+}, Tm{sup 3+}, Sm{sup 3+}, and Ho{sup 3+} ions. The sapphire substrate was checked by the electron paramagnetic resonance method which showed a content of Cr{sup 3+} and Fe{sup 3+} impurities. The samples 5 × 5 mm{sup 2} were positioned in the classical straws and within an estimated accuracy of 10{sup −6 }emu, no ferromagnetic moment was detected in the temperature region of 2–300 K. The paramagnetic magnetization was studied for parallel and perpendicular orientation. In the case of GaN:Tb sample, at T = 2 K, a pronounced anisotropy with the easy axis perpendicular to the film was observed which can be explained by the lowest quasi-doublet state of the non-Kramers Tb{sup 3+} ion. The Weiss temperature deduced from the susceptibility data using the Curie-Weiss (C-W) law was found to depend substantially on the magnetic field.

  8. 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)

  9. Crystal growth of Sm0.3Tb0.7FeO3 and spin reorientation transition in Sm1−xTbxFeO3 orthoferrite

    International Nuclear Information System (INIS)

    Wu, Anhua; Wang, Bo; Zhao, Xiangyang; Xie, Tao; Man, Peiwen; Su, Liangbi; Kalashnikova, A.M.; Pisarev, R.V.

    2017-01-01

    In this work, Sm 0.3 Tb 0.7 FeO 3 single crystal was successfully grown by optical floating zone method. Sm 0.3 Tb 0.7 FeO 3 samples with a-, b-, and c-orientation were manufactured by means of Laue photograph. Magnetic properties of Sm 0.3 Tb 0.7 FeO 3 single crystals are studied over a wide temperature range from 2 to 400 K. Spin reorientation transition from Γ 2 to Γ 4 are observed by means of the temperature dependence of magnetization It indicated the reorientation transition temperature of Sm 1−x Tb x FeO 3 single crystals is lowered with the contents of Tb contents rising based on this work and our previous works, thus the spin reorientation transition temperature can be adjusted through changing the compound in orthoferrites materials, which means that we can get orthoferrites single crystals with high magnetism property in various temperature through material design. - Highlights: • Sm 0.3 Tb 0.7 FeO 3 single crystals with various compounds were successfully grown by optical floating zone method. • The relation between SRT temperature and composition in Sm 1−x Tb x FeO 3 orthoferrite was indicated. • The spin reorientation transition temperature of Sm 1−x Tb x FeO 3 single crystals can be adjusted through changing the compound in orthoferrites materials.

  10. 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 Sub ject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 2.686, year: 2016

  11. X-ray excited photoluminescence near the giant resonance in solid-solution Gd(1-x)Tb(x)OCl nanocrystals and their retention upon solvothermal topotactic transformation to Gd(1-x)Tb(x)F3.

    Science.gov (United States)

    Waetzig, Gregory R; Horrocks, Gregory A; Jude, Joshua W; Zuin, Lucia; Banerjee, Sarbajit

    2016-01-14

    Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb(3+) centers upon excitation in proximity to the giant resonance of the host Gd(3+) ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism from multiple exciton generation to single thermal exciton formation and Auger decay processes. The solid-solution Gd1-xTbxOCl nanocrystals are further topotactically transformed with retention of a nine-coordinated cation environment to solid-solution Gd1-xTbxF3 nanocrystals upon solvothermal treatment with XeF2. The metastable hexagonal phase of GdF3 can be stabilized at room temperature through this topotactic approach and is transformed subsequently to the orthorhombic phase. The fluoride nanocrystals indicate an analogous but blue-shifted modulation of the X-ray excited optical luminescence of the Tb(3+) centers upon X-ray excitation near the giant resonance of the host Gd(3+) ions.

  12. Hydrothermal synthesis and luminescent properties of LnPO4:Tb,Bi (Ln=La,Gd) phosphors under UV/VUV excitation

    International Nuclear Information System (INIS)

    Wang Yuhua; Wu Chunfang; Wei Jie

    2007-01-01

    Monoclinic LnPO 4 :Tb,Bi (Ln=La,Gd) phosphors were prepared by hydrothermal reaction and their luminescent properties under ultraviolet (UV) and vacuum ultraviolet (VUV) excitation were investigated. LaPO 4 :Tb,Bi phosphor and GdPO 4 :Tb phosphor showed the strongest emission intensity under 254 and 147 nm excitation, respectively, because of the different energy transfer models. In UV region, Bi 3+ absorbed most energy then transferred to Tb 3+ , but in VUV region it was the host which absorbed most energy and transferred to Tb 3+

  13. Calculations of the Low-Lying Structures in the Even-Even Nd/Sm/Gd/Dy Isotopes

    Science.gov (United States)

    Lee, Su Youn; Lee, J. H.; Lee, Young Jun

    2018-05-01

    The nuclear structure of deformed nuclei has been studied using the interacting boson model (IBM). In this study, energy levels and E2 transition probabilities were determined for even nuclei in the Nd/Sm/Gd/Dy chains which have a transition characteristic between the rotational, SU(3) and vibrational, U(5) limits. The structure of the nuclei exhibits a slight breaking of the SU(3) symmetry in the direction of U(5), and therefore, we add the d-boson number operator n d , which is the main term of the U(5) symmetric Hamiltonian, to the SU(3) Hamiltonian of the IBM. The calculated results for low-lying energy levels and E2 transition rates in Nd/Sm/Gd/Dy isotopes are in reasonably good agreement with known experimental results.

  14. 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)

  15. Luminescence, Energy Transfer and Tunable Color of Ce3+- and Tb3+-Activated Na3Gd(BO3)2 Phosphors

    Science.gov (United States)

    Zhang, Xinguo; Pan, Jialiang; Mo, Fuwang

    2017-07-01

    A series of blue Na3Gd(BO3)2:Ce3+ and blue-to-green color-tunable Na3Gd (BO3)2:Ce3+,Tb3+ phosphors were synthesized by the solid-state method. The luminescence, concentration quenching and energy transfer (ET) process of Na3Gd(BO3)2:Ce3+,Tb3+ were investigated. Both Ce3+ and Tb3+ occupy the Gd3+ site in the Na3Gd(BO3)2 host. Na3Gd(BO3)2:Ce3+ exhibits strong ultraviolet absorption and broadband blue emission. The Ce3+ sensitization effect on Tb3+ has been verified by the variation of PL/PLE spectra, the Ce3+ decay lifetimes and the energy transfer efficiency of Na3Gd(BO3)2:Ce3+,Tb3+ phosphors. The maximum Ce3+-Tb3+ ET efficiency has been calculated to be 95%. The emitting color of the obtained phosphors can be modulated from blue (0.179, 0.204) through bluish-green (0.271, 0.391) to green (0.349, 0.551) by properly changing the ratio of Ce3+/Tb3+.

  16. Electronic and magnetic properties of SmCrSb3 and GdCrSb3: A first principles study

    International Nuclear Information System (INIS)

    Sandeep; Ghimire, M.P.; Thapa, R.K.

    2011-01-01

    The density of states (DOS) and the magnetic moments of SmCrSb 3 and GdCrSb 3 have been studied by first principles full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT). For the exchange-correlation potential, the local-spin density approximations with correlation energy (LSDA+U) method have been used. Total and partial DOS have been computed using the WIEN2k code. DOS result shows the exchange-splittings of Cr-3d and rare-earth (R) 4f states electrons, which are responsible for the ground state ferromagnetic (FM) behavior of the systems. The FM behavior of these systems is strongly influenced by the average number of Cr-3d and Sm (Gd) 4f-electrons. The effective moment of SmCrSb 3 is found to be 7.07 μ B while for GdCrSb 3 it is 8.27 μ B . The Cr atom plays a significant role on the magnetic properties due to the hybridization between Cr-3d and Sb-5p states. - Highlights: → DOS and the magnetic moments of SmCrSb 3 and GdCrSb 3 are studied by full-FP-LAPW method. → Exchange splitting of eg and t2g of Cr-3d states and the rare-earth 4f state electrons are responsible for ground state ferromagnetism. → Rare-earth magnetic moments are greater than Cr moment indicating presence of 4f states.

  17. 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.

  18. Sol-gel syntheses, luminescence, and energy transfer properties of α-GdB5O9:Ce(3+)/Tb(3+) phosphors.

    Science.gov (United States)

    Sun, Xiaorui; Gao, Wenliang; Yang, Tao; Cong, Rihong

    2015-02-07

    Sol-gel method was applied to prepare homogenous and highly crystalline phosphors with the formulas α-GdB5O9:xTb(3+) (0 ≤ x ≤ 1), α-Gd1-xCexB5O9 (0 ≤ x ≤ 0.40), α-GdB5O9:xCe(3+), 0.30Tb(3+) (0 ≤ x ≤ 0.15) and α-GdB5O9:0.20Ce(3+), xTb(3+) (0 ≤ x ≤ 0.10). The success of the syntheses was proved by the linear shrinkage or expansion of the cell volumes against the substitution contents. In α-GdB5O9:xTb(3+), an efficient energy transfer from Gd(3+) to Tb(3+) was observed and there was no luminescence quenching. The exceptionally high efficiency of the f-f excitations of Tb(3+) implies that these phosphors may be good green-emitting UV-LED phosphors. For α-Gd1-xCexB5O9, Ce(3+) absorbs the majority of the energy and transfers it to Gd(3+). Therefore, the co-doping of Ce(3+) and Tb(3+) leads to a significant enhancement in the green emission of Tb(3+). Our current results together with the study on α-GdB5O9:xEu(3+) in the literature indicate that α-GdB5O9 is a good phosphor host with advantages including controllable preparation, diverse cationic doping, the absence of concentration quenching, and effective energy transfer.

  19. Energy transfer and tunable multicolor emission and paramagnetic properties of GdF3:Dy(3+),Tb(3+),Eu(3+) phosphors.

    Science.gov (United States)

    Guan, Hongxia; Sheng, Ye; Xu, Chengyi; Dai, Yunzhi; Xie, Xiaoming; Zou, Haifeng

    2016-07-20

    A series of Dy(3+), Tb(3+), Eu(3+) singly or doubly or triply doped GdF3 phosphors were synthesized by a glutamic acid assisted one-step hydrothermal method. The samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and photoluminescence (PL) spectroscopy. The results show that the synthesized samples are all pure GdF3. The obtained samples have a peanut-like morphology with a diameter of about 270 nm and a length of about 600 nm. Under UV excitation, GdF3:Dy(3+), GdF3:Tb(3+) and GdF3:Eu(3+) samples exhibit strong blue, green and red emissions, respectively. By adjusting their relative doping concentrations in the GdF3 host, the different color hues of green and red light are obtained by co-doped Dy(3+), Tb(3+) and Tb(3+), Eu(3+) ions in the GdF3 host, respectively. Besides, there exist two energy transfer pairs in the GdF3 host: (1) Dy(3+) → Tb(3+) and (2) Tb(3+) → Eu(3+). More significantly, in the Dy(3+), Tb(3+), and Eu(3+) tri-doped GdF3 phosphors, white light can also be achieved upon excitation of UV light by adjusting the doping concentration of Eu(3+). In addition, the obtained samples also exhibit paramagnetic properties at room temperature (300 K) and low temperature (2 K). It is obvious that multifunctional Dy(3+), Tb(3+), Eu(3+) tri-doped GdF3 materials including tunable multicolors and intrinsic paramagnetic properties may have potential applications in the field of full-color displays.

  20. Magnetic properties of the germanides RE{sub 3}Pt{sub 4}Ge{sub 6} (RE=Y, Pr, Nd, Sm, Gd-Dy)

    Energy Technology Data Exchange (ETDEWEB)

    Eustermann, Fabian; Eilers-Rethwisch, Matthias; Renner, Konstantin; Hoffmann, Rolf-Dieter; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Janka, Oliver [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Oldenburg Univ. (Germany). Inst. fuer Chemie

    2017-07-01

    The germanides RE{sub 3}Pt{sub 4}Ge{sub 6} (RE=Y, Pr, Nd, Sm, Gd-Dy) have been synthesized by arc-melting of the elements followed by inductive annealing to improve the crystallinity and allow for structural order. The compounds have been studied by powder X-ray diffraction; additionally the structure of Y{sub 3}Pt{sub 4}Ge{sub 6} has been refined from single-crystal X-ray diffractometer data. It exhibits a (3+1)D modulated structure, indicating isotypism with Ce{sub 3}Pt{sub 4}Ge{sub 6}. The crystal structure can be described as an intergrowth between YIrGe{sub 2}- and CaBe{sub 2}Ge{sub 2}-type slabs along [100]. Temperature-dependent magnetic susceptibility measurements showed Pauli paramagnetism for Y{sub 3}Pt{sub 4}Ge{sub 6} and Curie-Weiss paramagnetism for Pr{sub 3}Pt{sub 4}Ge{sub 6} and Nd{sub 3}Pt{sub 4}Ge{sub 6}. Sm{sub 3}Pt{sub 4}Ge{sub 6} exhibits van Vleck paramagnetism, while antiferromagnetic ordering at T{sub N}=8.1(1) K and T{sub N}=11.0(1) K is observed for Gd{sub 3}Pt{sub 4}Ge{sub 6} and Tb{sub 3}Pt{sub 4}Ge{sub 6}, respectively.

  1. Luminescent GdVO_4:Sm"3"+ quantum dots enhance power conversion efficiency of bulk heterojunction polymer solar cells by Förster resonance energy transfer

    International Nuclear Information System (INIS)

    Bishnoi, Swati; Gupta, Vinay; Sharma, Gauri D.; Chand, Suresh; Sharma, Chhavi; Kumar, Mahesh; Haranath, D.; Naqvi, Sheerin

    2016-01-01

    In this work, we report enhanced power conversion efficiency (PCE) of bulk heterojunction polymer solar cells by Förster resonance energy transfer (FRET) from samarium-doped luminescent gadolinium orthovanadate (GdVO_4:Sm"3"+) quantum dots (QDs) to polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) polymer. The photoluminescence emission spectrum of GdVO_4:Sm"3"+ QDs overlaps with the absorption spectrum of PTB7, leading to FRET from GdVO_4:Sm"3"+ to PTB7, and significant enhancements in the charge-carrier density of excited and polaronic states of PTB7 are observed. This was confirmed by means of femtosecond transient absorption spectroscopy. The FRET from GdVO_4:Sm"3"+ QDs to PTB7 led to a remarkable increase in the power conversion efficiency (PCE) of PTB7:GdVO_4:Sm"3"+:PC_7_1BM ([6,6]-phenyl-C_7_1-butyric acid methyl ester) polymer solar cells. The PCE in optimized ternary blend PTB7:GdVO_4:Sm"3"+:PC_7_1BM (1:0.1:1.5) is increased to 8.8% from 7.2% in PTB7:PC_7_1BM. This work demonstrates the potential of rare-earth based luminescent QDs in enhancing the PCE of polymer solar cells.

  2. Ternary rhombohedral Laves phases RE_2Rh_3Ga (RE = Y, La-Nd, Sm, Gd-Er)

    International Nuclear Information System (INIS)

    Seidel, Stefan; Benndorf, Christopher; Heletta, Lukas; Poettgen, Rainer; Eckert, Hellmut; Sao Paulo Univ., Sao Carlos

    2017-01-01

    The ordered Laves phases RE_2Rh_3Ga (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_2Ni_3Si 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"2 values, 10 variables for Y_2Rh_3Ga, a=562.5(2), c=1194.4(2) pm, wR2=0.0519, 206 F"2 values, 11 variables for Ce_2Rh_3Ga and a=556.7(2), c=1184.1(3) pm, wR2=0.0396, 176 F"2 values, 11 variables for Tb_2Rh_3Ga. The Rh_3Ga tetrahedra are condensed via common corners and the large cavities left by the network are filled by the rare earth atoms. The RE_2Rh_3Ga Laves phases crystallize with a translationengleiche subgroup of the cubic RERh_2 Laves phases with MgCu_2 type. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y_2Rh_3Ga and La_2Rh_3Ga. Ce_2Rh_3Ga shows intermediate cerium valence while all other RE_2Rh_3Ga phases are Curie-Weiss paramagnets which order magnetically at low temperatures. The "8"9Y and "7"1Ga solid state nuclear magnetic resonance (NMR) spectra of the diamagnetic representative Y_2Rh_3Ga show well-defined single resonances in agreement with an ordered bulk phase. In comparison to the binary Laves phase YRh_2 a strongly increased "8"9Y resonance frequency is observed owing to a higher s-electron spin density at the "8"9Y nuclei as proven by density of states (DOS) calculations.

  3. Enhanced photoluminescence of Sm{sup 3+}/Bi{sup 3+} co-doped Gd{sub 2}O{sub 3} phosphors by combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guangsheng; Zhang Ying [Institute of Micro-system Physics, School of Physics and Electronics, Henan University, Kaifeng 475001 (China); Yin Jiang [Department of Physics, Nanjing University, Nanjing 210093 (China); Zhang, W.F. [Institute of Micro-system Physics, School of Physics and Electronics, Henan University, Kaifeng 475001 (China)], E-mail: wfzhang@henu.edu.cn

    2008-12-15

    Gd{sub 2}O{sub 3}:Sm{sup 3+} and Gd{sub 2}O{sub 3}:Sm{sup 3+},Bi{sup 3+} powders were prepared by a combustion method. Their structures were determined using X-ray diffraction. UV-visible absorption and photoluminescence spectra were investigated for Gd{sub 2}O{sub 3}:Sm{sup 3+} and Gd{sub 2}O{sub 3}:Sm{sup 3+},Bi{sup 3+} at different annealing temperatures and different doping concentrations. The emission spectra of all samples presented the characteristic emission narrow lines arising from the {sup 4}G{sub 5/2}{yields}{sup 6}H{sub J} transitions (J=5/2, 7/2, and 9/2) of Sm{sup 3+} ions upon excitation with UV irradiation. The emission intensity of Sm{sup 3+} ions was largely enhanced with introducing Bi{sup 3+} ions into Gd{sub 2}O{sub 3}:Sm{sup 3+} and the maximum occurred at a Bi{sup 3+} concentration of 0.5 mol%. The relevant mechanisms were discussed with the sensitization theory by Dexter and the aggregation behavior of Bi{sup 3+} ions.

  4. Investigations on the determination of traces of some rare earths (Eu, Sm, Gd, Y) in oxides of rare earths (Y2O3, Sm2O3, Gd2O3) by emission spectrography in d.c. arc

    International Nuclear Information System (INIS)

    Dittrich, K.; Gajek, M.; Luan, P.

    1978-01-01

    The evaporation of traces and matrices of rare earth elements was investigated in different atmospheres. It was found, that low-boiling rare earths elements, because of their extended formation of carbides evaporate more slowly than high-boiling rare earths elements. The evaporation of the traces depends on the matrices. 3 cases for the determination of traces of rare earths elements in oxides of other rare earths elements are derived from the results of the evaporation: Low- to high-boiling traces of rare earths elements in low-boiling matrices of rare earths elements, low-boiling traces in medium- to high-boiling matrices, and medium- to high-boiling traces in medium- to high-boiling matrices. The results of the determination are: in Y 2 O 3 : 14 ppm Sm, 2 ppm Eu; in Gd 2 O 3 : 18 ppm Y, 3 ppm Sm, 2 ppm Eu; in Sm 2 O 3 : 70 ppm Y, 370 ppm Gd, 16 ppm Eu. (author)

  5. Host-Sensitized and Tunable Luminescence of GdNbO4:Ln3+ (Ln3+ = Eu3+/Tb3+/Tm3+) Nanocrystalline Phosphors with Abundant Color.

    Science.gov (United States)

    Liu, Xiaoming; Chen, Chen; Li, Shuailong; Dai, Yuhua; Guo, Huiqin; Tang, Xinghua; Xie, Yu; Yan, Liushui

    2016-10-17

    Up to now, GdNbO 4 has always been regarded as an essentially inert material in the visible region with excitation of UV light and electron beams. Nevertheless, here we demonstrate a new recreating blue emission of GdNbO 4 nanocrystalline phosphors with a quantum efficiency of 41.6% and host sensitized luminescence in GdNbO 4 :Ln 3+ (Ln 3+ = Eu 3+ /Tb 3+ /Tm 3+ ) nanocrystalline phosphors with abundant color in response to UV light and electron beams. The GdNbO 4 and GdNbO 4 :Ln 3+ (Ln 3+ = Eu 3+ /Tb 3+ /Tm 3+ ) nanocrystalline phosphors were synthesized by a Pechini-type sol-gel process. With excitation of UV light and low-voltage electron beams, the obtained GdNbO 4 nanocrystalline phosphor presents a strong blue luminescence from 280 to 650 nm centered around 440 nm, and the GdNbO 4 :Ln 3+ nanocrystalline phosphors show both host emission and respective emission lines derived from the characterize f-f transitions of the doping Eu 3+ , Tb 3+ , and Tm 3+ ions. The luminescence color of GdNbO 4 :Ln 3+ nanocrystalline phosphors can be tuned from blue to green, red, blue-green, orange, pinkish, white, etc. by varying the doping species, concentration, and relative ratio of the codoping rare earth ions in GdNbO 4 host lattice. A single-phase white-light-emission has been realized in Eu 3+ /Tb 3+ /Tm 3+ triply doped GdNbO 4 nanocrystalline phosphors. The luminescence properties and mechanisms of GdNbO 4 and GdNbO 4 :Ln 3+ (Ln 3+ = Eu 3+ /Tb 3+ /Tm 3+ ) are updated.

  6. Experimental and theoretical study of pure and doped crystals: Gd2O2S, Gd2O2S:Eu3+ and Gd2O2S:Tb3+

    Science.gov (United States)

    Wang, Fei; Chen, Xiumin; Liu, Dachun; Yang, Bin; Dai, Yongnian

    2012-08-01

    Quantum chemistry and experimental method were used to study on pure and doped Gd2O2S crystals in this paper. The band structure and DOS diagrams of pure and doped Gd2O2S crystals which calculated by using DFT (Density Functional Theory) method were illustrated to explain the luminescent properties of impurities in crystals. The calculations of the crystal structure were finished by using the program of CASTEP (Cambridge Sequential Total Energy Package). The samples showed the characteristic emissions of Tb3+ ions with 5D4-7FJ transitions and Eu3+ ions with 5D0-7FJ transitions which emit pure green luminescence and red luminescence respectively. The experimental excitation spectra of Tb3+ and Eu3+ doped Gd2O2S are in agreement of the DOS diagrams over the explored energy range, which has allowed a better understanding of different luminescence mechanisms of Tb3+ and Eu3+ in Gd2O2S crystals.

  7. Transition to intermediate valence state and x-ray photoemission in Sm/sub 1-x/Gd/sub x/S

    International Nuclear Information System (INIS)

    Campagna, M.; Chui, S.T.; Wertheim, G.K.; Tosatti, E.

    1976-01-01

    We report a systematic x-ray photoemission study of the alloys Sm 1 /sub -//subx/Gd/subx/S for 0 2+ → Sm 3+ photoemission line shape using a model which has some similarities with the Jaccarino-Walker model for magnetic alloys. It assumes the existence of only two different kinds of Sm 2+ ions in Sm 1 /sub -//subx/Gd/subx/S for x approximately-less-than 16%. We discuss possible reasons for the fact that Gd does not show the usual clustering effects known to occur in many substitutional rare-earth alloys. Lattice-constant measurements for various substituents further illustrate the importance of electronic effects in the phase transition

  8. Syntheses and crystal structures of BaAgTbS{sub 3}, BaCuGdTe{sub 3}, BaCuTbTe{sub 3}, BaAgTbTe{sub 3}, and CsAgUTe{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Jai; Beard, Jessica C.; Ibers, James A. [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113 (United States); Mesbah, Adel [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113 (United States); ICSM-UMR 5257 CNRS/CEA/UM2/ENSCM, Bat 426, BP 17171, 30207 Bagnols/Ceze (France)

    2015-06-15

    Five new quaternary chalcogenides of the 1113 family, namely BaAgTbS{sub 3}, BaCuGdTe{sub 3}, BaCuTbTe{sub 3}, BaAgTbTe{sub 3}, and CsAgUTe{sub 3}, were synthesized by the reactions of the elements at 1173-1273 K. For CsAgUTe{sub 3} CsCl flux was used. Their crystal structures were determined by single-crystal X-ray diffraction studies. The sulfide BaAgTbS{sub 3} crystallizes in the BaAgErS{sub 3} structure type in the monoclinic space group C{sup 3},{sub 2h}-C2/m, whereas the tellurides BaCuGdTe{sub 3}, BaCuTbTe{sub 3}, BaAgTbTe{sub 3}, and CsAgUTe{sub 3} crystallize in the KCuZrS{sub 3} structure type in the orthorhombic space group D{sup 1},{sub 2}{sup 7},{sub h}-Cmcm. The BaAgTbS{sub 3} structure consists of edge-sharing [TbS{sub 6}{sup 9-}] octahedra and [AgS{sub 5}{sup 9-}] trigonal pyramids. The connectivity of these polyhedra creates channels that are occupied by Ba atoms. The telluride structure features {sup 2}{sub ∞}[MLnTe{sub 3}{sup 2-}] layers for BaCuGdTe{sub 3}, BaCuTbTe{sub 3}, BaAgTbTe{sub 3}, and {sup 2}{sub ∞}[AgUTe{sub 3}{sup 1-}] layers for CsAgUTe{sub 3}. These layers comprise [MTe{sub 4}] tetrahedra and [LnTe{sub 6}] or [UTe{sub 6}] octahedra. Ba or Cs atoms separate these layers. As there are no short Q..Q (Q = S or Te) interactions these compounds achieve charge balance as Ba{sup 2+}M{sup +}Ln{sup 3+}(Q{sup 2-}){sub 3} (Q = S and Te) and Cs{sup +}Ag{sup +}U{sup 4+}(Te{sup 2-}){sub 3}. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Host-sensitized luminescence properties in CaNb2O6:Ln(3+) (Ln(3+) = Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+)) phosphors with abundant colors.

    Science.gov (United States)

    Li, Kai; Liu, Xiaoming; Zhang, Yang; Li, Xuejiao; Lian, Hongzhou; Lin, Jun

    2015-01-05

    A series of Ln(3+) (Ln(3+) = Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+)) ion doped CaNb2O6 (CNO) phosphors have been prepared via the conventional high-temperature solid-state reaction route. The X-ray diffraction (XRD) and structure refinement, diffuse reflection, photoluminescence (PL), and fluorescent decay curves were used to characterize the as-prepared samples. Under UV radiation, the CNO host present a broad emission band from about 355 to 605 nm centered around 460 nm originating from the NbO6 octahedral groups, which has spectral overlaps with the excitation of f-f transitions of Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+) in CNO:Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+) samples. They show both host emission and respective emission lines derived from the characteristic f-f transitions of activators, which present different emission colors owing to the energy transfer from the NbO6 group in the host to Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+) with increasing activator concentrations. The decreases of decay lifetimes of host emissions in CNO:Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+) demonstrate the energy transfer from the hosts to Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+). The energy transfer mechanisms in CNO:Eu(3+)/Tb(3+)/Dy(3+) phosphors have been determined to be a resonant type via dipole-dipole mechanisms. For CNO:Sm(3+), the metal-metal charge transfer transition (MMCT) might contribute to the different variations of decay lifetimes and emission intensity from CNO:Eu(3+)/Tb(3+)/Dy(3+) samples. The best quantum efficiency is 71.2% for CNO:0.01/0.02Dy(3+). The PL properties of as-prepared materials indicate the promising application in UV-pumped white-emitting lighting diodes field.

  10. A template-free solvothermal synthesis and photoluminescence properties of multicolor Gd2O2S:xTb3+, yEu3+ hollow spheres

    Science.gov (United States)

    Sang, Xiaotong; Xu, Guangxi; Lian, Jingbao; Wu, Nianchu; Zhang, Xue; He, Jiao

    2018-06-01

    The multicolor Gd2O2S:xTb3+, yEu3+ hollow spheres were successfully synthesized via a template-free solvothermal route without the use of surfactant from commercially available Ln (NO3)3·6H2O (Ln = Gd, Tb and Eu), absolute ethanol, ethanediamine and sublimed sulfur as the starting materials. The phase, structure, particle morphology and photoluminescence (PL) properties of the as-obtained products were investigated by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM) and photoluminescence spectra. The influence of synthetic time on phase, structure and morphology was systematically investigated and discussed. The possible formation mechanism depending on synthetic time t for the Gd2O2S phase has been presented. These results demonstrate that the Gd2O2S hollow spheres could be obtained under optimal condition, namely solvothermal temperature T = 220 °C and synthetic time t = 16 h. The as-obtained Gd2O2S sample possesses hollow sphere structure, which has a typical size of about 2.5 μm in diameter and about 0.5 μm in shell thickness. PL spectroscopy reveals that the strongest emission peak for the Gd2O2S:xTb3+ and the Gd2O2S:yEu3+ samples is located at 545 nm and 628 nm, corresponding to 5D4→7F5 transitions of Tb3+ ions and 5D0→7F2 transitions of Eu3+ ions, respectively. The quenching concentration of Tb3+ ions and Eu3+ ions is 7%. In the case of Tb3+ and Eu3+ co-doped samples, when the concentration of Tb3+ or Eu3+ ions is 7%, the optimum concentration of Eu3+ or Tb3+ ions is determined to be 1%. Under 254 nm ultraviolet (UV) light excitation, the Gd2O2S:7%Tb3+, the Gd2O2S:7%Tb3+,1%Eu3+ and the Gd2O2S:7%Eu3+ samples give green, yellow and red light emissions, respectively. And the corresponding CIE coordinates vary from (0.3513, 0.5615), (0.4120, 0.4588) to (0.5868, 0.3023), which is also well consistent with their luminous photographs.

  11. Optical and magneto-optical properties of single crystals of RFe{sub 2} (R = Gd, Tb, Ho, and Lu) and GdCo{sub 2} intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.J.

    1999-02-12

    The author has studied the diagonal and off-diagonal optical conductivity of RFe{sub 2}(R = Gd, Tb, Ho, Lu) and GdCo{sub 2} single crystals grown by the flux method. Using spectroscopic ellipsometry the author has measured the dielectric function from 1.5 to 5.5 eV. The magneto-optical Kerr spectrometer at temperatures between 7 and 295 K and applied magnetic fields between 0.5 to 1.6 T. The apparatus and calibration method are described in detail. Using magneto-optical data and optical constants he derives the experimental value of the off-diagonal conductivity components. Theoretical calculations of optical conductivities and magneto-optical parameters were performed using the tight binding-linear muffin tin orbitals method within the local spin density approximation. He applied this TB-LMTO method to LuFe{sub 2}. The theoretical results obtained agree well with the experimental data. The oxidation effects on the diagonal part of the optical conductivity were considered using a three-phase model. The oxidation effects on the magneto-optical parameters were also considered by treating the oxide layer as a nonmagnetic thin transparent layer. These corrections change not only the magnitude but also the shape of the optical conductivity and the magneto-optical parameters.

  12. 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

  13. Theoretical investigations on the magnetocaloric and barocaloric effects in Tb{sub y}Gd{sub (1−y)}Al{sub 2} series

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, P.O.; Alho, B.P.; Alvarenga, T.S.T.; Nóbrega, E.P. [Instituto de Física, Universidade do Estado do Rio de Janeiro – UERJ, Rua São Francisco Xavier, 524, 20550-013 RJ (Brazil); Carvalho, A.Magnus G. [Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo – UNIFESP, 12231-280 São José dos Campos, SP (Brazil); Instituto Nacional de Metrologia, Qualidade e Tecnologia – INMETRO, 25250-020 Duque de Caxias, RJ (Brazil); Sousa, V.S.R. de; Caldas, A.; Oliveira, N.A. de [Instituto de Física, Universidade do Estado do Rio de Janeiro – UERJ, Rua São Francisco Xavier, 524, 20550-013 RJ (Brazil); Ranke, P.J. von, E-mail: von.ranke@uol.com.br [Instituto de Física, Universidade do Estado do Rio de Janeiro – UERJ, Rua São Francisco Xavier, 524, 20550-013 RJ (Brazil)

    2013-06-25

    Highlights: ► Anisotropic magnetocaloric effect in in Tb{sub 0.4}Gd{sub 0.6}Al{sub 2}. ► Prediction of barocaloric effect in Tb{sub 0.4}Gd{sub 0.6}Al{sub 2}. ►An optimal hybrid magnetocaloric material using Tb{sub y}Gd{sub (1-y)}Al{sub 2} compounds. -- Abstract: We report the calculations on the magnetocaloric and barocaloric effects in ferromagnetic series Tb{sub y}Gd{sub (1−y)}Al{sub 2}. Our model includes the crystalline electrical field interaction, exchange interactions among Tb–Tb, Gd–Gd and Tb–Gd magnetic ions and the Zeeman effect for an anisotropic system. The lattice and electronic entropies were included in adiabatic processes. The magnetocaloric effect calculated for magnetic field changes along the easy magnetic direction 〈1 1 1〉 is in good agreement with the experimental data. Calculation along the hard magnetization direction 〈0 0 1〉 predicts anomalous magnetocaloric effect, which was ascribed to the spin reorientation processes. From the available experimental data of Curie temperature dependence on pressure, the exchange model parameters were scaled and the barocaloric effect was calculated.

  14. Superdeformed bands in /sup 150/Gd and /sup 151/Tb: Evidence for the influence of high-N intruder states at large deformations

    Energy Technology Data Exchange (ETDEWEB)

    Fallon, P.; Alderson, A.; Bentley, M.A.; Bruce, A.M.; Forsyth, P.D.; Howe, D.; Roberts, J.W.; Sharpey-Schafer, J.F.; Twin, P.J.; Beck, F.A.

    1989-02-16

    Rotational bands, characteristic of a superdeformed prolate shape (epsilon approx. = 0.6) and extending to above spin 60 Planck constant, have been observed in both /sup 150/Gd and /sup 151/Tb. The magnitudes of the moments of inertia I/sup (2)/ were found to vary with frequency and the variation greatly exceeded that seen in /sup 148,149/Gd and /sup 151,152/Dy. The differences in the I/sup (2)/'s are attributed to the occupation of particular high-N orbitals. Moreover, contrary to the previous examples the bands in both /sup 150/Gd and /sup 151/Tb de-excited at a much higher rotational frequency of Planck constant..omega.. approx. = 0.4 MeV and this may indicate that the pair gap extends to higher frequencies in /sup 150/Gd and /sup 151/Tb.

  15. Eu{sup 3+}/Tb{sup 3+} doped cubic BaGdF{sub 5} multifunctional nanophosphors: Multicolor tunable luminescence, energy transfer and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Honglan; Liu, Guixia, E-mail: liuguixia22@163.com; Wang, Jinxian; Dong, Xiangting; Yu, Wensheng

    2017-06-15

    A series of BaGdF{sub 5}:Eu{sup 3+}/Tb{sup 3+} orange-green-yellow-white emitting nanophosphors (NPs) were successfully synthesized via hydrothermal method without assistance of any surfactant, catalyst, or template. The nanocrystals are in sphere-like morphology with an average size of approximately 46 nm. The quenching concentrations of Eu{sup 3+} and Tb{sup 3+} single doped BaGdF{sub 5} phosphors are 5.5% and 15%, respectively. The tunable color tone can be obtained in Eu{sup 3+} and Tb{sup 3+} co-doped BaGdF{sub 5} phosphors, the strong orange-white and green-yellow emissions can be seen in BaGdF{sub 5}:5.5%Eu{sup 3+}, y%Tb{sup 3+} and BaGdF{sub 5}:3.5%Tb{sup 3+}, x%Eu{sup 3+} phosphors, especially. More significantly, we realize the more standard white emission with a CIE chromaticity diagram point at (0.317, 0.321) and a lower correlated color temperature of 6979 K in the BaGdF{sub 5}: 5.5%Eu{sup 3+}, 4.5%Tb{sup 3+} sample. In addition, the energy transfer phenomenon from Tb{sup 3+} to Eu{sup 3+} ions is clearly observed in Tb{sup 3+}, Eu{sup 3+} co-doped BaGdF{sub 5} phosphors and the energy transfer efficiency can reach a maximum of 75%. Moreover, the as-prepared samples exhibit paramagnetic properties at room temperature. This type of multifunctional multicolor emitting nanophosphor has promising applications in the fields of full-color displays, biomedical science, MRI, and so on. - Graphical abstract: The cubic phase BaGdF{sub 5}:Eu{sup 3+}/Tb{sup 3+} sphere-like nanophosphors were prepared. Energy transfer mechanism, color-tunable emissions and magnetic properties of BaGdF{sub 5}:Eu{sup 3+}/Tb{sup 3+} have been studied, which could have promising applications in the fields of full-color displays, MRI and biomedical science, and so on.

  16. Synthesis RMn{sub 2}O{sub 5} (R = Gd and Sm) nano- and microstructures by a simple hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Gangqiang, E-mail: zgq2006@snnu.edu.cn [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Liu Peng [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Hojamberdiev, Mirabbos [Shaanxi Key Laboratory of Nano-materials and Technology, Xi' an University of Architecture and Technology, Xi' an 710055 (China); Ge Bao [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Liu Yun; Miao Hongyan; Tan Guoqiang [College of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi' an 710021 (China)

    2009-12-15

    Single-phase RMn{sub 2}O{sub 5} (R = Gd and Sm) nano- and microstructures have been successfully synthesized via a simple hydrothermal process at 250 deg. C for 24 h using NaOH as mineralizer. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and selective area electron diffraction patterns (SAED) were used to characterize the as-synthesized GdMn{sub 2}O{sub 5} and SmMn{sub 2}O{sub 5} samples. The effect of NaOH concentration and the molar ratio of Mn{sup 2+}/Mn{sup 7+} on the morphology and size of the final products was studied, and a possible formation mechanism of RMn{sub 2}O{sub 5} (R = Gd and Sm) nanoplates and nanorods under hydrothermal conditions was proposed.

  17. Hyperfine interaction studies of the perovskite oxides of the type RCrO3 (R = Gd, Tb e Dy)

    International Nuclear Information System (INIS)

    Silva, Renilson Adriano da

    2009-01-01

    ABO 3 perovskite oxides have ideal cubic structure, however, some distortions in this type of structure may induce changes from cubic to orthorhombic or rhombroedric symmetry. The larger atoms A are located at the center of a cube, the B atoms are on 8 vertices and oxygen atoms occupy 12 positions in the middle of each side of the cube. Distortions in this structure may lead to new magnetic and electrical properties, with great scientific and technological interest. In this work RCrO 3 (R = Gd, Tb, Dγ) compounds (also known as orthocromites) were studied. The samples were produced by means of sol-gel chemical procedure and analyzed by X-Ray Diffraction. The results showed a single phase with Pbnm space group. The perturbed gamma-gamma angular correlation (PAC) measurements were carried out using 181 Hf( 181 Ta) and 111 In( 111 Cd) nuclear probes, which substitute 'A' and 'B' positions respectively. The probe nuclei were introduced in the samples during the chemical procedures for preparation. One of the objectives of this work's was to study the hyperfine magnetic field and its variation as a function of temperature, crystallographic structure as well as the antiferromagnetic transition temperature (T N ). The PAC Measurements were carried out in the temperature range of 20 to 300 K for R = Gd, Tb and 20 to 800 K in the case of R = Dγ from. Electric field gradient was also measured as a function of temperature. It was possible to observe the expected transition as well as the alignment of Cr spins, as found in literature. The Neel temperatures (TN) for investigated samples are ∼170 K, ∼164 K and ∼148 K for GdCrO 3 , TbCrO 3 and DyCrO 3 respectively. (author)

  18. Fabrication and characterization of Gd2O2SO4:Tb3+ phosphors by sol-gel method

    Science.gov (United States)

    Aritman, I.; Yildirim, S.; Kisa, A.; Guleryuz, L. F.; Yurddaskal, M.; Dikici, T.; Celik, E.

    2017-02-01

    The objective of the innovative approaches of the scintillation materials to be used in the digital portal imaging systems in the radiotherapy applications is to research the GOS material production that has been activated with the rare earth elements (RE), to produce the scintillation detectors that have a rapid imaging process with a lesser radiation and higher image quality from these materials and to apply the radiographic imaging systems. The GOS: Tb3+ showed high emission peak and high x-ray absorption properties which have been determined for application to mammography and dental radiography. In this study, Gd2O2SO4:Tb3+ phosphors were fabricated by the sol-gel method that is a unique technique and not previously applied. Besides, the structural characterization of GOS: Tb3+ has been investigated. The strongest emission peak located at 549 nm under 312 nm UV light excitation was appeared on the GOS: Tb3+ phosphor particles. The characterization processing optimized by using FTIR, DTA-TG, XRD, XPS, SEM and the luminescence spectroscopy.

  19. Giant magnetic coercivity in YNi{sub 4}B-type SmNi{sub 3}TB (T=Mn–Cu) solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jinlei; Yan, Chang [Research Center for Solid State Physics and Materials, School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009 (China); Yapaskurt, V.O. [Department of Petrology, Geological Faculty Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation)

    2016-12-01

    The effects of transition metal substitution for Ni on the magnetic properties of the YNi{sub 4}B-type SmNi{sub 4}B via SmNi{sub 3}TB (T=Mn, Fe, Co, Cu) solid solutions have been investigated. SmNi{sub 4}B, SmNi{sub 3}MnB, SmNi{sub 3}FeB, SmNi{sub 3}CoB and SmNi{sub 3}CuB show ferromagnetic ordering at 40 K, 210 K, 322 K, 90 K and 57 K and field sensitive metamagnetic-like transitions at 15 K, 100 K, 185 K, 55 K and 15 K in a magnetic field of 10 kOe, respectively. The magnetocaloric effects of SmNi{sub 3}TB (T=Mn–Cu) were calculated in terms of isothermal magnetic entropy change (ΔS{sub m}). The magnetic entropy ΔS{sub m} reaches value of –0.94 J/kg K at 40 K for SmNi{sub 4}B, –1.5 J/kg K at 205 K for SmNi{sub 3}MnB, –0.54 J/kg K at 320 K for SmNi{sub 3}FeB, –0.49 J/kg K at 90 K for SmNi{sub 3}CoB and –0.54 J/kg K at 60 K for SmNi{sub 3}CuB in field change of 0–50 kOe around the Curie temperature. They show positive ΔS{sub m} of +0.71 J/kg K at ~10 K for SmNi{sub 4}B, +1.69 J/kg K at 30 K for SmNi{sub 3}MnB, +0.89 J/kg K at 110 K for SmNi{sub 3}FeB, +1.08 J/kg K at 25 K for SmNi{sub 3}CoB and +1.12 J/kg K at 10 K for SmNi{sub 3}CuB in field change of 0–50 kOe around the low temperature metamagnetic-like transition. Below the field induced transition temperature (change of magnetic structure), SmNi{sub 3}TB (T=Mn–Cu) exhibits giant magnetic coercivity of 74 kOe at 5 K for SmNi{sub 4}B, 69 kOe at 20 K (90 kOe at 10 K) for SmNi{sub 3}MnB, 77 kOe at 60 K for SmNi{sub 3}FeB, 88 kOe at 20 K for SmNi{sub 3}CoB and 52 kOe at 5 K for SmNi{sub 3}CuB. - Highlights: • YNi{sub 4}B-type SmNi{sub 3}{Mn, Fe, Co, Ni, Cu}B exhibit the Curie points at 39–322 K. • SmNi{sub 3}{Mn, Fe, Co, Ni, Cu}B show field induced transition at 15–185 K. • SmNi{sub 3}MnB shows huge magnetic hysteresis with coercive field of 69 kOe at 20 K. • SmNi{sub 3}FeB shows huge magnetic hysteresis with coercive field of 77 kOe at 60 K. • SmNi{sub 3}CoB shows giant coercive

  20. Photoluminescence and thermoluminescence properties of Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Palvi; Bedyal, A.K. [School of Physics, Shri Mata Vaishno Devi University, Katra, 182320 Jammu and Kashmir (India); Kumar, Vinay, E-mail: vinaykdhiman@yahoo.com [School of Physics, Shri Mata Vaishno Devi University, Katra, 182320 Jammu and Kashmir (India); Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA9300 (South Africa); Khajuria, Y. [School of Physics, Shri Mata Vaishno Devi University, Katra, 182320 Jammu and Kashmir (India); Lochab, S.P. [Inter University Accelerator Centre, Anura Asaf Ali Marg, P. O. Box 10502, New Delhi 110067 (India); Pitale, S.S. [Crystal Technology Laboratory,TPD, Bhabha Atomic Research Centre Trombay, Mumbai 400085 (India); Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA9300 (South Africa); Ntwaeaborwa, O.M.; Swart, H.C. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA9300 (South Africa)

    2014-12-15

    Energy level diagram of Tb{sup 3+} ion in the K{sub 3}Gd(PO{sub 4}){sub 2} host lattice. - Highlights: • First time, a detailed TL and PL study on undoped and Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor. • Combustion method was employed to synthesize the Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor. • Mechanism of excitation and emission in undoped and Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor was given. - Abstract: Tb{sup 3+} doped nanoparticulate K{sub 3}Gd(PO{sub 4}){sub 2} phosphor was prepared by combustion method using urea as a fuel. The structure, optical and luminescent properties of the phosphor were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and thermoluminescence (TL) spectroscopy. In undoped K{sub 3}Gd(PO{sub 4}){sub 2}, the excitation and emission peaks at 273 nm and 323 nm belongs to the {sup 8}S{sub 7/2} → {sup 6}I{sub J(J=7/2)} and {sup 6}P{sub J(J=7/2)} → {sup 8} S{sub 7/2} transitions of Gd{sup 3+} while green emission was observed in the Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2}. TL study was carried out after exposing the samples to γ-radiations (0.1–5 kGy) in the K{sub 3}Gd(PO{sub 4}){sub 2}:Tb{sup 3+} (1.5 mol%). The calculated kinetic parameters were compared with different methods. The band gap of the phosphor was estimated as 5.80 eV. The green shade of the Tb{sup 3+} ion with the CIE coordinates (x, y) as (0.29, 0.54) was in good agreement with the well known green phosphors.

  1. Luminescence and energy transfer of Tb3+-doped BaO-Gd2O3-Al2O3-B2O3-SiO2 glasses.

    Science.gov (United States)

    Zuo, Chenggang; Huang, Jinze; Liu, Shaoyou; Xiao, Anguo; Shen, Youming; Zhang, Xiangyang; Zhou, Zhihua; Zhu, Ligang

    2017-12-05

    Transparent Tb 3+ -doped BaO-Gd 2 O 3 -Al 2 O 3 -B 2 O 3 -SiO 2 glasses with the greater than 4g/cm 3 were prepared by high temperature melting method and its luminescent properties have been investigated by measured UV-vis transmission, excitation, emission and luminescence decay spectra. The transmission spectrum shows there are three weak absorption bands locate at about 312, 378 and 484nm in the glasses and it has good transmittance in the visible spectrum region. Intense green emission can be observed under UV excitation. The effective energy transfer from Gd 3+ ion to Tb 3+ ion could occur and sensitize the luminescence of Tb 3+ ion. The green emission intensity of Tb 3+ ion could change with the increasing SiO 2 /B 2 O 3 ratio in the borosilicate glass matrix. With the increasing concentration of Tb 3+ ion, 5 D 4 → 7 F J transitions could be enhanced through the cross relaxation between the two nearby Tb 3+ ions. Luminescence decay time of 2.12ms from 546nm emission is obtained. The results indicate that Tb 3+ -doped BaO-Gd 2 O 3 -Al 2 O 3 -B 2 O 3 -SiO 2 glasses would be potential scintillating material for applications in X-ray imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Photoluminescence characteristics of reddish-orange Eu{sup 3+} or Sm{sup 3+} singly-doped and Eu{sup 3+} and Sm{sup 3+} co-doped KZnGd(PO{sub 4}){sub 2} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jun Ho; Bandi, Vengala Rao; Grandhe, Bhaskar Kumar; Jang, Ki Wan; Lee, Ho Sueb [Changwon National University, Changwon (Korea, Republic of); Yi, Soung Soo [Silla University, Busan (Korea, Republic of); Jeong, Jung Hyun [Pukyong National University, Busan (Korea, Republic of)

    2011-02-15

    Eu{sup 3+} or Sm{sup 3+} singly-doped and Eu{sup 3+} and Sm{sup 3+} co-doped KZnGd(PO{sub 4}){sub 2} phosphors were synthesized by using a conventional solid state reaction method at 750 .deg. C. The emission spectra of KZnGd{sub 1-x}(PO{sub 4}){sub 2}:Eu{sup 3+}{sub x} with {lambda}{sub ex} = 395 nm and KZnGd{sub 1-y}(PO{sub 4}){sub 2}:Sm{sup 3+}{sub y} with {lambda}{sub ex} = 403 nm phosphors showed intense {sup 5}D{sub 0} {yields} {sup 7}F{sub 1}, {sup 4}G{sub 5/2} {yields} {sup 6}H{sub 7/2} emission transitions at 595 nm and 599 nm, respectively. The optimum relative intensity of the KZnGd{sub 1-x-y}(PO{sub 4}){sub 2}:Eu{sup 3+}{sub x} , Sm{sup 3+}{sub y} phosphor was obtained for the doping concentrations of (x = 0.09, y = 0.01). In addition, the temperature dependent luminescence intensity of the synthesized phosphors was investigated and the thermal stability of the KZnGd(PO{sub 4}){sub 2}:Eu{sup 3+} phosphor was found to be higher than that of standard YAG:Ce{sup 3+} and KZnGd{sub 1-x-y}(PO{sub 4}){sub 2}:Eu{sup 3+}{sub x} Sm{sup 3+}{sub y} under near ultra-violet (NUV) light emitting diode excitation (LED). Therefore, we suggest that Eu{sup 3+} or Sm{sup 3+} singly-doped and Eu{sup 3+} and Sm{sup 3+} co-doped KZnGd(PO{sub 4}){sub 2} phosphors should be efficient for different red-color-emitting display device applications and NUV-LED-based white-light-emitting diodes.

  3. 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.

  4. Field and sample history dependence of the compensation temperature in Sm0.97Gd0.03Al2

    International Nuclear Information System (INIS)

    Vaidya, U.V.; Rakhecha, V.C.; Sumithra, S.; Ramakrishnan, S.; Grover, A.K.

    2007-01-01

    We present magnetization data on three polycrystalline specimens of Sm 0.97 Gd 0.03 Al 2 : (1) as-cast (grainy texture), (2) powder, and (3) re-melted fast-quenched (plate). The data are presented for nominally zero- (ZFC) and high-field-cooling (HFC) histories. A zero cross-over in magnetization curve at some temperature T=T 0 was seen in ZFC data on grainy and powder samples, but not in the plate sample. At fields surpassing magnetocrystalline anisotropy, a 4f magnetic moment flip was still evidenced by HFC data in all samples at a compensation temperature T comp , which must necessarily be treated as distinct from T 0 (T 0 may not even exist). Proper understanding of T comp should take account of thermomagnetic history effects

  5. Development of Tb{sup 3+} activated gadolinium aluminate garnet (Gd{sub 3}Al{sub 5}O{sub 12}) as highly efficient green-emitting phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Xin; Li, Jinkai, E-mail: mse_lijk@ujn.edu.cn; Duan, Guangbin; Liu, Zongming, E-mail: ost_liuzm@ujn.edu.cn

    2016-11-15

    The powder processing of (Gd{sub 1-x}Tb{sub x}){sub 3}Al{sub 5}O{sub 12} (GdAG:Tb{sup 3+}) solid solutions was achieved through precursor synthesized via carbonate precipitation, followed by calcination at 1500 °C. The performance of the GdAG:Tb{sup 3+} phosphors were characterized by the combined techniques of XRD, FE-SEM, HR-TEM, PLE/PL, and fluorescence decay analyses. Lower Tb{sup 3+} doping can stabilize the crystal structure of GdAG garnet against its thermal decomposition. The GdAG:Tb{sup 3+} phosphors with good dispersion and fairly uniform particle morphology exhibit a series of {sup 5}D{sub 4}–{sup 7}F{sub J} transitions of Tb{sup 3+} with strongest green emission at ~544 nm ({sup 5}D{sub 4}–{sup 7}F{sub 5} transitions of Tb{sup 3+}) under UV excitation at ~277 nm (4f{sup 8}−4f{sup 7}5d{sup 1} transition of Tb{sup 3+}). The later is overlapping with {sup 8}S{sub 7/2}–{sup 6}I{sub J} intra f–f transition of Gd{sup 3+} indirectly suggesting the existence of energy transfer from Gd{sup 3+} to Tb{sup 3+}. With the Gd{sup 3+}–Tb{sup 3+} energy transfer, higher Tb{sup 3+} emission and quantum efficiency than the well-known YAG:Tb{sup 3+} and LuAG:Tb{sup 3+} were obtained in the present work. The effects of Tb{sup 3+} content on luminescent property of the phosphor, especially PLE/PL properties, fluorescence lifetime and quantum efficient, were thoroughly investigated, which were also compared to those of Tb{sup 3+}-activated YAG and LuAG compounds. The CIE chromaticity coordinates and quenching concentration of GdAG:Tb{sup 3+} were determined to be (~0.37, ~0.56) and ~10 at%, respectively. Keeping the optimum Tb{sup 3+} content at ~10 at%, the (Gd{sub 0.9}Tb{sub 0.1})AG phosphor possesses high internal and external quantum efficiencies of ~88.7% and ~73.6% under ~277 nm excitation, respectively. Owing to its improved luminescent property and high theoretical density, the phosphors of (Gd{sub 1-x}Tb{sub x})AG garnet developed in the present work are

  6. Optically stimulated luminescence of Tb{sup 3+}/Sm{sup 3+} doubly doped K{sub 2}YF{sub 5} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, L.; Marcazzo, J.; Santiago, M.; Caselli, E. [Universidad Nacional del Centro de la Provincia de Buenos Aires, Instituto de Fisica Arroyo Seco, Gral. Pinto 399, B7000GHG, Tandil (Argentina); Khaidukov, N. M., E-mail: jmarcass@exa.unicen.edu.ar [Kurnakov Institute of General and Inorganic Chemistry, RAS, Leninskii Prospekt 31, 119991 Moscow (Russian Federation)

    2014-08-15

    In this work optically stimulated luminescence (OSL) properties of K{sub 2}YF{sub 5} crystals doubly doped with Tb{sup 3+} and Sm{sup 3+} ions have been investigated for the first time. OSL responses for different dopant concentration and for optical stimulation with different wavelengths have been analyzed for each compound. Dosimetric properties of the most efficient composition, namely, K{sub 2}YF{sub 5}:1.0 at.% Tb{sup 3+}; 1.0 at.% Sm{sup 3+}, have been studied. Finally, the possible application of this single crystal as OSL dosimeter has been evaluated. (Author)

  7. Determination of diffusion coefficients for sulfide ions in solid electrolytes on the basis of BaSm2S4 and CaGd2S4

    International Nuclear Information System (INIS)

    Yurlov, I.S.; Ushakova, Yu.N.; Medvedeva, O.V.; Kalinina, L.A.; Shirokova, G.I.; Ananchenko, B.A.

    2007-01-01

    Coefficients of self-diffusion and coefficients of diffusion of the sulfur ion in solid electrolytes BaSm 2 S 4 and CaGd 2 S 4 are determined with recourse to methods of conductometry and potentiostatic chronoamperometry. A vacancy mechanism for the defect formation in solid solutions on the basis of barium thiosamarate and calcium thiogadolynate is proposed [ru

  8. 'Gigantic' increase of AFMR frequencies induced by nonmagnetic impurity ions in orthoferrites RFe1-xAlxO3 (R=Gd,Tb)

    International Nuclear Information System (INIS)

    Mukhin, A.A.; Parsegov, I.Yu.

    1996-01-01

    We observed a 'gigantic' increase (up to three times) of the AFMR frequencies ν 1,2 with decreasing temperature in GdFe 0.9 Al 0.1 O 3 and TbFe 0.925 Al 0.075 O 3 in contrast to pure GdFeO 3 and TbFeO 3 . The effects observed are explained by the appearance of an additional exchange field H mv ∼20 -36 kOe on rare-earth ions due to decompensation of the surrounding antiferromagnetically ordered Fe ions near nonmagnetic impurity ions. (orig.)

  9. Magnetism of cyano-bridged hetero-one-dimensional Ln3+-M3+ complexes (Ln3+ = Sm, Gd, Yb; M3+ = FeLS, Co).

    Science.gov (United States)

    Figuerola, Albert; Diaz, Carmen; Ribas, Joan; Tangoulis, Vassilis; Sangregorio, Claudio; Gatteschi, Dante; Maestro, Miguel; Mahía, José

    2003-08-25

    The reaction of Ln(NO(3))(3).aq with K(3)[Fe(CN)(6)] or K(3)[Co(CN)(6)] and 2,2'-bipyridine in water led to five one-dimensional complexes: trans-[M(CN)(4)(mu-CN)(2)Ln(H(2)O)(4) (bpy)](n)().XnH(2)O.1.5nbpy (M = Fe(3+) or Co(3+); Ln = Sm(3+), Gd(3+), or Yb(3+); X = 4 or 5). The structures for [Fe(3)(+)-Sm(3+)] (1), [Fe(3)(+)-Gd(3+)] (2), [Fe(3)(+)-Yb(3+)] (3), [Co(3)(+)-Gd(3+)] (4), and [Co(3)(+)-Yb(3+)] (5) have been solved; they crystallize in the triclinic space P1 and are isomorphous. The [Fe(3+)-Sm(3+)] complex is a ferrimagnet, its magnetic studies suggesting the onset of weak ferromagnetic 3-D ordering at 3.5 K. The [Fe(3+)-Gd(3+)] interaction is weakly antiferromagnetic. The isotropic nature of Gd(3+) allowed us to evaluate the exchange interaction (J = 0.77 cm(-)(1)).

  10. Thermoelectric properties, crystal and electronic structure of semiconducting RECuSe{sub 2} (RE = Pr, Sm, Gd, Dy and Er)

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeili, Mehdi [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Tseng, Yu-Chih [CANMET Materials, Natural Resources Canada, 183 Longwood Road South, Hamilton, Ontario L8P 0A5 (Canada); Mozharivskyj, Yurij, E-mail: mozhar@mcmaster.ca [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada)

    2014-10-15

    Highlights: • Crystal and electronic structure of monoclinic and trigonal RECuSe{sub 2} phases. • Thermoelectric properties of the RECuSe{sub 2} phases. • Temperature stability of the RECuSe{sub 2} phases. - Abstract: The ternary RECuSe{sub 2} phases have been prepared and structurally characterized. They adopt either a monoclinic structure (P2{sub 1}/c, z = 4) for lighter rare earths (RE = Pr, Sm and Gd) or Cu-disordered trigonal structure for heavier rare-earths (P3{sup ¯}m1, z = 1, RE = Dy and Er). The resistivity and Seebeck coefficient measurements on GdCuSe{sub 2}, DyCuSe{sub 2} and ErCuSe{sub 2} indicate that the studied phases are p-type semiconductors with relatively small activation energies (0.045–0.11 eV). However, their electrical resistivities are too high (0.45–220 Ω cm at room temperature) to make them competitive thermoelectric materials. Electronic structure calculations indicate presence of a band gap in the RECuSe{sub 2} phases.

  11. Thermoelectric properties, crystal and electronic structure of semiconducting RECuSe2 (RE = Pr, Sm, Gd, Dy and Er)

    International Nuclear Information System (INIS)

    Esmaeili, Mehdi; Tseng, Yu-Chih; Mozharivskyj, Yurij

    2014-01-01

    Highlights: • Crystal and electronic structure of monoclinic and trigonal RECuSe 2 phases. • Thermoelectric properties of the RECuSe 2 phases. • Temperature stability of the RECuSe 2 phases. - Abstract: The ternary RECuSe 2 phases have been prepared and structurally characterized. They adopt either a monoclinic structure (P2 1 /c, z = 4) for lighter rare earths (RE = Pr, Sm and Gd) or Cu-disordered trigonal structure for heavier rare-earths (P3 ¯ m1, z = 1, RE = Dy and Er). The resistivity and Seebeck coefficient measurements on GdCuSe 2 , DyCuSe 2 and ErCuSe 2 indicate that the studied phases are p-type semiconductors with relatively small activation energies (0.045–0.11 eV). However, their electrical resistivities are too high (0.45–220 Ω cm at room temperature) to make them competitive thermoelectric materials. Electronic structure calculations indicate presence of a band gap in the RECuSe 2 phases

  12. Direct two-photon excitation of Sm3+, Eu3+, Tb3+, Tb.DOTA-, and Tb.propargylDO3A in solution

    Science.gov (United States)

    Sørensen, Thomas Just; Blackburn, Octavia A.; Tropiano, Manuel; Faulkner, Stephen

    2012-07-01

    We have observed direct two-photon excitation of samarium, europium and terbium ions in solution upon near IR excitation using a tuneable pulsed light source, and have also studied two-photon processes in a pair of related terbium complexes, namely [Tb.DOTA]- and Tb.propargylDO3A. Direct two-photon excitation of lanthanides is observed in simple systems in the absence of sensitizing chromophores. Where even simple chromophores such as a triple bond are present in the complex, then single and two-photon excitation of chromophore excited states competes with direct two-photon excitation of the ions and is the dominant pathway for sensitizing formation of the lanthanide excited state.

  13. Synthesis, structure and photoluminescence of novel lanthanide (Tb(III), Gd(III)) complexes with 6-diphenylamine carbonyl 2-pyridine carboxylate

    International Nuclear Information System (INIS)

    An Baoli; Gong Menglian; Cheah, Kok-Wai; Wong, Wai-Kwok; Zhang Jiming

    2004-01-01

    A novel organic ligand, 6-diphenylamine carbonyl 2-pyridine carboxylic acid (HDPAP), and the corresponding lanthanide complexes, tris(6-diphenylamine carbonyl 2-pyridine carboxylato) terbium(III) (Tb-DPAP) and tris(6-diphenylamine carbonyl 2-pyridine carboxylato) gadolinium(III) (Gd-DPAP) have been designed and synthesized. The crystal structure and photoluminescence of Tb-DPAP and Gd-DPAP have been studied. The results showed that the lanthanide complexes have electroneutral structures, and the solid terbium complex emits characteristic green fluorescence of Tb(III) ions at room temperature while the gadolinium complex emits the DPAP ligand phosphorescence. The lowest triplet level of DPAP ligand was calculated from the phosphorescence spectrum of Gd-DPAP in N,N-dimethyl formamide (DMF) dilute solution determined at 77 K, and the energy transfer mechanisms in the lanthanide complexes were discussed. The lifetimes of the 5 D 4 levels of Tb 3+ ions in the terbium complex were examined using time-resolved spectroscopy, and the values are 0.0153±0.0001 ms for solid Tb(DPAP) 3 ·11.5H 2 O and 0.074±0.007 ms for 2.5x10 -5 mol/l Tb-DPAP ethanol solution

  14. Spectroscopic study of magnetic phase transitions and magnetic structures in rare earth ferroborates RFe3(BO3)4 (R = Y, Er, Tb, Gd)

    International Nuclear Information System (INIS)

    Popova, M.N.; Chukalina, E.P.; Stanislavchuk, T.N.; Bezmaternykh, L.N.

    2006-01-01

    One investigated into the absorption spectra of RFe 3 (BO 3 ) 4 , R=Y, Er, Tb, Gd rare earth borate single crystals containing erbium (1%) introduced to serve as a probe. On the basis of the temperature dependences of Er 3+ ion spectral line splittings one determined the values of the magnetic ordering temperatures of Er, Tb and Gd ferroborates and the temperatures of the spin reoriented first order phase transition in GdFe 3 (BO 3 ) 4 :Er 3+ (1%). On the basis of comparison of the splitting values of Er 3+ ion ground state in RFe 3 (BO 3 ) 4 (R=Y, Er, Tb) and in GdFe 3 (BO 3 )4 compounds the magnetic structure of which is known one makes a concussion about the orientation of iron magnetic moments in the magneto-ordered state: a lightly planar structure is observed for YFe 3 (BO 3 ) 4 and ErFe 3 (BO 3 ) 4 and a lightly axial one - for TbFe 3 (BO 3 ) 4 . One discusses the role of R 3+ ion single ion anisotropy when determining the magnetic structure type in RFe 3 (BO 3 ) 4 [ru

  15. 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)

  16. Weak ferromagnetism in Re0.67Ca0.33FeO3 (Re=La, Sm, Gd) nanoparticles

    International Nuclear Information System (INIS)

    Li Jiangong; Kou Xinli; Qin Yong; He Haiying

    2003-01-01

    Perovskite-type complex ferrite Re 0.67 Ca 0.33 FeO 3 (Re=La, Sm, Gd) nanoparticles of nearly the same particle size were prepared using sol-gel method. The influence of rare-earth ions on weak ferromagnetism in the Re 0.67 Ca 0.33 FeO 3 nanoparticles has been studied. The spontaneous magnetization M s of the Sm 0.67 Ca 0.33 FeO 3 nanoparticles is greater than that of Gd 0.67 Ca 0.33 FeO 3 nanoparticles; and M s of Gd 0.67 Ca 0.33 FeO 3 nanoparticles is greater than that of La 0.67 Ca 0.33 FeO 3 nanoparticles. The ferromagnetic component arising from the Fe sublattice increases with the decreasing rare-earth ionic radii. The magnetization of the rare-earth ions in the Sm 0.67 Ca 0.33 FeO 3 nanoparticles is smaller than that in the Gd 0.67 Ca 0.33 FeO 3 nanoparticles. The influences of the geometric and intrinsic magnetic characters of rare-earth ions as well as the particle size of the nanoparticles on weak ferromagnetism are discussed

  17. Luminescence properties of Sm, Tb(Sal){sub 3}Phen complex in polyvinyl alcohol: an approach for white-light emission

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Gagandeep; Rai, S B, E-mail: sbrai49@yahoo.co.in [Laser and Spectroscopy Laboratory, Department of Physics Banaras Hindu University, Varanasi, 221005 (India)

    2011-10-26

    Polyvinyl alcohol polymer films doped with Sm,Tb(Sal){sub 3}Phen complexes have been synthesized using solution casting technique. An enhancement in absorption intensity is observed revealing the encapsulation of rare earth ions by salicylic acid (Sal)/1,10 phenanthroline (Phen) complex. Photoluminescence spectra of the co-doped samples were examined by varying the concentration of Tb{sup 3+} keeping concentration of Sm{sup 3+} ions fixed and vice-versa. It is found that the polymer samples emit a combination of blue, green and orange-red wavelengths tunable to white light when excited with 355 nm radiation. The emission spectra also show a self-quenching effect at higher concentration of Sm{sup 3+} ions. An efficient energy transfer was observed from Tb{sup 3+} : {sup 5}D{sub 4} {yields} Sm{sup 3+} : {sup 4}G{sub 9/2}. The reason for the enhancement in fluorescence intensities of Sm{sup 3+} in the co-doped polymer sample is the intermolecular as well as the intramolecular energy transfer.

  18. New intermetallic compounds Ln(Ag, AL)4 (Ln-Y, Gd, Tb, Dy) and their structure

    International Nuclear Information System (INIS)

    Kuz'ma, Yu.B.; Stel'makhovich, B.M.

    1990-01-01

    By the methods of X-ray analysis crystal structure of compounds Ln(Ag,Al) 4 , where Ln-Y, Gd, Tb, Dy, posessing rhombic structure, is determined. The intermetallics have been prepared for the first time. Ways of atom distribution and their coordinates in DyAg 0.55 Al 3.45 structure (a=0.4296(1), b=04179(1), c=0.9995(3), R=0.093) are specified. Other compounds are formed in case of LnAgAl 3 compositions. Interatomic distances in Dy(Ag,Al) 4 structure are considered. A supposition is made on the formation in Ln-Ag-Al systems of a greater number of intermetallic compounds

  19. Hard X-ray MCD in GdNi/sub 5/ and TbNi/sub 5/ single crystals

    CERN Document Server

    Galera, R M

    1999-01-01

    XMCD experiments have been performed at the R L/sub 2,3/ and Ni K- edges on magnetically saturated single crystals of GdNi/sub 5/ and Tb Ni/sub 5/ ferromagnetic compounds. The spectra present huge and well structured dichroic $9 signals at both the R L/sub 2,3/ and the Ni K- edges. Structures from the quadrupolar (2p to 4f) transitions are clearly observed at the R L/sub 2,3/-edges. Though Ni is not magnetic, large intensities, up to 0.4, are measured at the $9 Ni K- edge. The Ni K-edge XMCD shows a three-peak structure which intensities dependent on the rare earth. (7 refs).

  20. Analysis of green luminescent Tb3+:Ca4GdO(BO3)3 powder phosphor

    International Nuclear Information System (INIS)

    Vengala Rao, B.; Rambabu, U.; Buddhudu, S.

    2007-01-01

    This paper reports on the emission analysis of a green luminescent Tb 3+ :Ca 4 GdO(BO 3 ) 3 powder phosphor based on the measurements of excitation, emission and lifetimes. Besides this, we have also observed an intense green emission from this powder phosphor under an UV source. The emission transitions of ( 5 D 4 →7 F 3,4,5,6 ) with λ exci =257 nm have been measured. Particularly, the green emission transition ( 5 D 4 →7 F 5 ) at 553 nm has been found to be more prominent and intense. Such green strong emission displaying powder phosphor will find applications in the development of coated screens in certain electronic systems. Apart from the emission analysis of this phosphor, XRD, SEM and FTIR studies have also been carried out in order to understand the structural details of it

  1. Surfactant mediated hydrothermal synthesis, characterization and luminescent properties of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} core shell nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Khajuria, Heena; Ladol, Jigmet; Khajuria, Sonika; Shah, Mohd Syed; Sheikh, H.N., E-mail: hnsheikh@rediffmail.com

    2016-08-15

    Highlights: • Core shell nanorods were synthesised by surfactant assisted hydrothermal method. • Morphology of core shell nanorods resembles those of core nanorods indicating coating of shell on cores. • More uniform and non-aggregated core shell nanorods were prepared in presence of surfactants. • Surfactant assisted prepared core shell nanorods show intense emission as compared to uncoated core nanorods. - Abstract: Core shell GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} nanorods were synthesized via hydrothermal route in the presence of different surfactants [cetyltrimethyl ammonium bromide (CTAB) and Sodium dodecyl sulphate (SDS)]. The nanorods were characterized by powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and photoluminescence (PL) studies. The X-ray diffraction results indicate good crystallinity and effective doping in core and core shell nanorods. SEM and TEM micrographs show that all of the as prepared gadolinium phosphate products have rod like shape. The compositional analysis of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} core was done by EDS. The emission intensity of the GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} core shell increased significantly with respect to those of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} core nanorods. The effect of surfactant on the uniformity, thickness and luminescence of the core shell nanorods was investigated.

  2. 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.

  3. 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.

  4. Observation of magnetization reversal behavior in Sm0.9Gd0.1Cr0.85Mn0.15O3 orthochromites

    Science.gov (United States)

    Panwar, Neeraj; Joby, Jostin P.; Kumar, Surendra; Coondoo, Indrani; Vasundhara, M.; Kumar, Nitu; Palai, Ratnakar; Singhal, Rahul; Katiyar, Ram S.

    2018-05-01

    Impact of co-doping (Gd and Mn) on the magnetic properties has been systematically investigated in SmCrO3 compound. For the synthesized compound Sm0.9Gd0.1Cr0.85Mn0.15O3 (SGCMO), below the Neel transition temperature and under low applied magnetic field, temperature induced magnetization reversal at 105 K (crossover temperature) was noticed in the field cooled magnetization curve. Magnetization reversal attained maximum value of -1.03 emu/g at 17 K where spin reorientation occurred. The magnetization reversal disappeared under higher applied field. From the M-H plots an enhancement in the magnetization was observed due to Gd doping. Magnetocaloric effect at low temperatures measured through the magnetic entropy change was found sixteen times higher for this compound as compared to pristine SmCrO3 and twice to that of SmCr0.85Mn0.15O3 compound. The study reveals the importance of co-doping in tailoring the magnetic properties of rare-earth chromites.

  5. RNi{sub 8}Si{sub 3} (R=Gd,Tb): Novel ternary ordered derivatives of the BaCd{sub 11} type

    Energy Technology Data Exchange (ETDEWEB)

    Pani, M., E-mail: marcella@chimica.unige.it [Department of Chemistry, University of Genova, Via Dodecaneso 31, 16146 Genova (Italy); Institute SPIN-CNR, Corso Perrone 24, 16152 Genova (Italy); Morozkin, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, Moscow, GSP-2 119992 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Provino, A.; Manfrinetti, P. [Department of Chemistry, University of Genova, Via Dodecaneso 31, 16146 Genova (Italy); Institute SPIN-CNR, Corso Perrone 24, 16152 Genova (Italy); Nirmala, R. [Indian Institute of Technology Madras, Chennai 600036 (India); Malik, S.K. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59082-970 (Brazil)

    2016-01-15

    The title compounds have been synthesized and characterized both from the structural and magnetic point of view. Both crystallize in a new monoclinic structure strictly related to the tetragonal BaCd{sub 11} type. The structure was solved by means of X-ray single-crystal techniques for GdNi{sub 8}Si{sub 3} and confirmed for TbNi{sub 8}Si{sub 3} on powder data; the corresponding lattice parameters (obtained from Guinier powder patterns) are a=6.3259(2), b=13.7245(5), c=7.4949(3) Å, β=113.522(3)°, V{sub cell}=596.64(3) Å{sup 3} and a=6.3200(2), b=13.6987(4), c=7.4923(2) Å, β=113.494(2)°, V{sub cell}=594.88(2) Å{sup 3}. The symmetry relationship between the tI48-I4{sub 1}/amd BaCd{sub 11} aristotype and the new ordered mS48-C2/c GdNi{sub 8}Si{sub 3} derivative is described via the Bärnighausen formalism within the group theory. The large Gd–Gd (Tb–Tb) distances, mediated via Ni–Si network, likely lead to weak magnetic interactions. Low-field magnetization vs temperature measurements indicate weak and field-sensitive antiferromagnetic ground state, with ordering temperatures of 3 K in GdNi{sub 8}Si{sub 3} and about 2–3 K in TbNi{sub 8}Si{sub 3}. On the other hand, the isothermal field-dependent magnetization data show the presence of competing interactions in both compounds, with a field-induced ferromagnetic behavior for GdNi{sub 8}Si{sub 3} and a ferrimagnetic-like behavior in TbNi{sub 8}Si{sub 3} at the ordering temperature T{sub C/N} of about (or slightly higher than) 3K. The magnetocaloric effect, quantified in terms of isothermal magnetic entropy change ΔS{sub m}, has the maximum values of –19.8 J(kg K){sup −1} (at 4 K for 140 kOe field change) and −12.1 J(kg K){sup −1} (at 12 K for 140 kOe field change) in GdNi{sub 8}Si{sub 3} and TbNi{sub 8}Si{sub 3}, respectively. - Graphical abstract: GdNi{sub 8}Si{sub 3} and TbNi{sub 8}Si{sub 3} compounds are isostructural, and crystallize in a new monoclinic type strictly related to the tetragonal

  6. The RELixSn2 (RE=La–Nd, Sm, and Gd; 0≤x<1) series revisited. Synthesis, crystal chemistry, and magnetic susceptibilities

    International Nuclear Information System (INIS)

    Makongo, Julien P.A.; Suen, Nian-Tzu; Guo, Shengping; Saha, Shanta; Greene, Richard; Paglione, Johnpierre; Bobev, Svilen

    2014-01-01

    This study is concerned with the ternary compounds RELi x Sn 2 (RE=La–Nd, Sm, and Gd; 0≤x 2 phases. These materials crystallize with the base-centered orthorhombic space group Cmcm (No. 63), and can be formally assigned with the CeNiSi 2 structure type (Pearson symbol oC16). Our systematic single-crystal X-ray diffraction studies revealed substantial Li-deficiencies in all cases, with SmSn 2 (space group Cmmm, ZrGa 2 structure type, Pearson symbol oC12) and GdSn 2 (space group Cmcm, ZrSi 2 structure type, Pearson symbol oC12) being completely lithium-free. The structure refinements also uncovered positional disorder on the Sn site neighboring the vacancies. The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn 2 and GdSn 2 structures are devoid of any disorder. Temperature-dependent studies of the magnetic response of the title compounds are also presented and discussed. -- Graphical abstract: RELi x Sn 2 (RE=La–Nd, 0≤x 2 structure type (a). The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn 2 (b) and GdSn 2 (c) structures are devoid of any disorder. Highlights: • The crystal structures of the RELi x Sn 2 (RE=La–Nd, 0≤x 2 structure type or defect variant of the CeNiSi 2 structure type. • SmSn 2 is isotypic with the ZrGa 2 structure, while RESn 2 (RE=Gd–Lu) are isotypic with the ZrSi 2 structure

  7. Theoretical investigations on magnetic entropy change in amorphous and crystalline systems: Applications to RAg (R=Tb, Dy, Ho) and GdCuAl

    Energy Technology Data Exchange (ETDEWEB)

    Ranke, P.J. von, E-mail: von.ranke@uol.com.br [Instituto de Física, Universidade do Estado do Rio de Janeiro – UERJ, Rua São Francisco Xavier, 524, 20550-013 RJ (Brazil); Nóbrega, E.P. [Instituto de Física, Universidade do Estado do Rio de Janeiro – UERJ, Rua São Francisco Xavier, 524, 20550-013 RJ (Brazil); Caldas, A. [Sociedade Unificada de Ensino Superior e Cultura, SUESC, 20211-351 Rio de Janeiro, RJ (Brazil); Alho, B.P. [Instituto de Aplicação Fernando Rodrigues da Silveira, Universidade do Estado do Rio de Janeiro, Rua Santa Alexandrina, 288, 20260-232 RJ (Brazil); Ribeiro, P.O.; Alvarenga, T.S.T.; Lopes, P.H.O.; Sousa, V.S.R. de [Instituto de Física, Universidade do Estado do Rio de Janeiro – UERJ, Rua São Francisco Xavier, 524, 20550-013 RJ (Brazil); Carvalho, A. Magnus G. [Laboratório Nacional de Luz Síncrotron, CNPEM, 13083-970 Campinas, SP (Brazil); Oliveira, N.A. de [Instituto de Física, Universidade do Estado do Rio de Janeiro – UERJ, Rua São Francisco Xavier, 524, 20550-013 RJ (Brazil)

    2014-11-15

    We report theoretical investigations on the magnetic entropy changes in amorphous systems through two different assumptions. In the first assumption, the HPZ-anisotropic model is considered to deal with the random direction of magnetic moments, where the amorphous RAg (R=Tb, Dy and Ho) were used as prototypes systems. In the second assumption, the amorphisation is parameterized through the exchange interaction distribution and GdCuAl, in amorphous and crystalline structures, were considered as prototypes systems. Comparisons between the magnetic entropy changes under amorphisation and under the usual magnetic field variation were performed. The model reveals the dependence of refrigerant capacity on the amorphisation parameter, and an optimum amorphisation parameter was calculated. - Highlights: • Theoretical investigation on RAg (R=Tb, Dy and Ho) and GdCuAl amorphous alloys. • Magnetic entropy changes in GdCuAl in both amorphous and crystalline structures. • The refrigerant capacity was compared in both amorphous and crystalline phases.

  8. Preparation of SmBCO layer for the surface optimization of GdYBCO film by MOCVD process based on a simple self-heating technology

    Science.gov (United States)

    Zhao, Ruipeng; Zhang, Fei; Liu, Qing; Xia, Yudong; Lu, Yuming; Cai, Chuanbing; Tao, Bowan; Li, Yanrong

    2018-07-01

    The MOCVD process was adopted to grow the REBa2Cu3O7-δ ((REBCO), RE = rare earth elements) films on the LaMnO3 (LMO) templates. Meanwhile, the LMO-template tapes are heated by the joule effect after applying a heating current through the Hastelloy metal substrates. The surface of GdYBCO films prepared by MOCVD method is prone to form outgrowths. So the surface morphology of GdYBCO film is optimized by depositing the SmBCO layer, which is an important process method for the preparation of high-quality multilayer REBCO films. At last, the GdYBCO/SmBCO/GdYBCO multilayer films were successfully prepared on the LMO templates based on the simple self-heating method. It is demonstrated that the GdYBCO surface was well improved by the characterization analysis of scanning electron microscope. And the Δω of REBCO (005) and Δφ of REBCO (103), which were performed by an X-ray diffraction system, are respectively 1.3° and 3.3° What's more, the critical current density (Jc) has been more than 3 MA/cm2 (77 K, 0 T) and the critical current (Ic) basically shows a trend of good linear increase with the increase of the number of REBCO layers.

  9. Optical and magneto-optical characterization of TbFeCo and GdFeCo thin films for high-density recording

    International Nuclear Information System (INIS)

    Hendren, W R; Atkinson, R; Pollard, R J; Salter, I W; Wright, C D; Clegg, W W; Jenkins, D F L

    2003-01-01

    Thin, optically semi-infinite films of amorphous TbFeCo and GdFeCo, suitable for magneto-optical recording, have been deposited by DC magnetron sputtering onto glass. Ellipsometric techniques have been used to determine the complex refractive index and complex magneto-optical parameter of the films in the wavelength range 400-900 nm, thus characterizing the materials. A review of the literature is presented and shows that the results for the TbFeCo films compare favourably with published results obtained from measurements conducted in situ, with the films protected with ZnS barrier layers. It is found that GdFeCo and TbFeCo are optically very similar, but magneto-optically the materials are quite different

  10. Optical and magneto-optical characterization of TbFeCo and GdFeCo thin films for high-density recording

    Energy Technology Data Exchange (ETDEWEB)

    Hendren, W R [Department of Pure and Applied Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Atkinson, R [Department of Pure and Applied Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Pollard, R J [Department of Pure and Applied Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Salter, I W [Department of Pure and Applied Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Wright, C D [School of Engineering and Computer Science, University of Exeter, Exeter EX4 4QF (United Kingdom); Clegg, W W [CRIST, University of Plymouth, Plymouth PL4 8AA (United Kingdom); Jenkins, D F L [CRIST, University of Plymouth, Plymouth PL4 8AA (United Kingdom)

    2003-03-12

    Thin, optically semi-infinite films of amorphous TbFeCo and GdFeCo, suitable for magneto-optical recording, have been deposited by DC magnetron sputtering onto glass. Ellipsometric techniques have been used to determine the complex refractive index and complex magneto-optical parameter of the films in the wavelength range 400-900 nm, thus characterizing the materials. A review of the literature is presented and shows that the results for the TbFeCo films compare favourably with published results obtained from measurements conducted in situ, with the films protected with ZnS barrier layers. It is found that GdFeCo and TbFeCo are optically very similar, but magneto-optically the materials are quite different.

  11. Rare Earth Chalcogels NaLnSnS4 (Ln = Y, Gd, Tb) for Selective Adsorption of Volatile Hydrocarbons and Gases

    KAUST Repository

    Edhaim, Fatimah

    2017-06-28

    The synthesis and characterization of the rare earth chalcogenide aerogels NaYSnS4, NaGdSnS4, and NaTbSnS4 is reported. Rare earth metal ions like Y3+, Gd3+, and Tb3+ react with the chalcogenide clusters [SnS4]4– in aqueous formamide solution forming extended polymeric networks by gelation. Aerogels obtained after supercritical drying have BET surface areas of 649 m2·g–1 (NaYSnS4), 479 m2·g–1 (NaGdSnS4), and 354 m2·g–1 (NaTbSnS4). Electron microscopy and physisorption studies reveal that the new materials have pores in the macro (above 50 nm) and meso (2–50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO2 over CH4 or H2. The notable adsorption capacity for toluene (NaYSnS4: 1108 mg·g–1; NaGdSnS4: 921 mg·g–1; and NaTbSnS4: 645 mg·g–1) and high selectivity for gases (CO2/H2: 172 and CO2/CH4: 50 for NaYSnS4, CO2/H2: 155 and CO2/CH4: 37 for NaGdSnS4, and CO2/H2: 75 and CO2/CH4: 28 for NaTbSnS4) indicate potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes.

  12. Levels in Gd156 excited in the decay of 5.6 d Tb156

    DEFF Research Database (Denmark)

    Hansen, P.Gregers; Nielsen, O.B.; Sheline, R.K.

    1959-01-01

    The decay of 5.6 day Tb156 has been studied by means of a six gap β-ray spectrometer, scintillation spectrometers, and coincidence techniques. Conversion electron and γ-ray coincidence measurements have been used extensively for obtaining quantitative estimates of γ-ray intensities. A description...... for transitions to a rotational band are observed. These features are discussed in terms of a probable mixing of the rotational bands....

  13. Magnetic properties of CaCu{sub 5}-type RNi{sub 3}TSi (R=Gd and Tb, T=Mn, Fe, Co and Cu) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Knotko, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Yao, Jinlei [Research Center for Solid State Physics and Materials, School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009 (China); Yuan, Fang; Mozharivskyj, Y. [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1 (Canada); Nirmala, R. [Indian Institute of Technology Madras, Chennai 600036 (India); Quezado, S.; Malik, S.K. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59082-970 (Brazil)

    2015-12-15

    Magnetic properties and magnetocaloric effect of CaCu{sub 5}-type RNi{sub 3}TSi (R=Gd and Tb, T=Mn, Fe, Co and Cu) compounds have been investigated. Magnetic measurements of RNi{sub 3}TSi display the increasing of Curie temperature and the decreasing of magnetocaloric effect and saturated magnetic moment in the row of ‘RNi{sub 3}CuSi–RNi{sub 3}NiSi–RNi{sub 3}CoSi–RNi{sub 3}MnSi–RNi{sub 3}FeSi’. In contrast to GdNi{sub 3}{Mn, Fe, Co}Si, TbNi{sub 3}{Mn, Fe, Co}Si exhibit significant magnetic hysteresis. The coercive field increases from TbNi{sub 4}Si (~0.5 kOe) to TbNi{sub 3}CoSi (4 kOe), TbNi{sub 3}MnSi (13 kOe) and TbNi{sub 3}FeSi (16 kOe) in field of 50 kOe at 5 K, whereas TbNi{sub 3}CuSi exhibits a negligible coercive field. - Graphical abstract: Magnetic measurements of RNi{sub 3}TSi show the increasing of Curie temperature and the decreasing of magnetocaloric effect and saturated magnetic moment in the row of 'RNi{sub 3}CuSi–RNi{sub 3}NiSi–RNi{sub 3}CoSi–RNi{sub 3}MnSi–RNi{sub 3}FeSi'. In contrast to GdNi{sub 3}{Mn, Fe, Co}Si, TbNi{sub 3}{Mn, Fe, Co}Si exhibit significant magnetic hysteresis. The coercive field increases from TbNi{sub 4}Si (~0.5 kOe) to TbNi{sub 3}CoSi (4 kOe), TbNi{sub 3}MnSi (13 kOe) and TbNi{sub 3}FeSi (16 kOe) in field of 50 kOe at 5 K, whereas TbNi{sub 3}CuSi exhibits a negligible coercive field. - Highlights: • CaCu{sub 5}-type RNi{sub 3}TSi show ferromagnetic ordering (R=Gd, Tb, T=Mn–Co, Cu). • Curie point increases in ‘RNi{sub 3}CuSi–RNi{sub 3}NiSi–RNi{sub 3}CoSi–RNi{sub 3}MnSi–RNi{sub 3}FeSi’ row. • MCE decreases in ‘RNi{sub 3}CuSi–RNi{sub 3}NiSi–RNi{sub 3}CoSi–RNi{sub 3}MnSi–RNi{sub 3}FeSi’ row. • TbNi{sub 3}{Mn, Fe, Co}Si exhibit significant magnetic hysteresis. • The coercive field of TbNi{sub 3}MnSi and TbNi{sub 3}FeSi reach 13 kOe and 16 kOe at 5 K.

  14. A study of luminescence from Eu"3"+, Ce"3"+, Tb"3"+ and Ce"3"+/Tb"3"+ in new potassium gadolinium phosphate K_3Gd_5(PO_4)_6

    International Nuclear Information System (INIS)

    Meng, Fangui; Zhang, Hongzhi; Chen, Cuili; Kim, Sun Il; Seo, Hyo Jin; Zhang, Xinmin

    2016-01-01

    New potassium gadolinium phosphate [K_3Gd_5(PO_4)_6] doped with Eu"3"+, Ce"3"+, Tb"3"+ and co-doped with Ce"3"+ and Tb"3"+ phosphors were prepared by high temperature solid state synthesis. Phase purity of the powders was checked by X-ray powder diffraction. Luminescence and excitation spectra of samples were reported. In particular, the interaction mechanism between Eu"3"+ ions was investigated in terms of the Inokuti–Hirayama model; it was found that the interactions between Eu"3"+ can be assigned to dipole–dipole interaction. K_3Gd_5(PO_4)_6:Eu"3"+ could act as a candidate for solid state lighting due to its strong absorption band in the near-UV region (350–400 nm). The energy transfer from Ce"3"+ to Tb"3"+ was confirmed and the mechanism was studied using Dexter's theory; it is concluded that electric dipole–dipole interaction predominates in the energy transfer process from Ce"3"+ to Tb"3"+ in the K_3Gd_5(PO_4)_6 host. The energy transfer efficiency and critical distance were also investigated. - Highlights: • Optical properties of K_3Gd_5(PO_4)_6:RE"3"+ are investigated for the first time. • The interaction mechanism between Eu"3"+ ions is attributed to dipole–dipole type. • K_3Eu_5(PO_4)_6 is a candidate phosphor for application to solid state lighting. • There exists an efficient energy transfer from Ce"3"+ to Tb"3"+ (η is up to 95%). • The mechanism of energy transfer process is electric dipole–dipole interaction.

  15. 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

  16. Effect of rapid quenching on the magnetism and magnetocaloric effect of equiatomic rare earth intermetallic compounds RNi (R = Gd, Tb and Ho)

    Energy Technology Data Exchange (ETDEWEB)

    Rajivgandhi, R. [Department of Physics, Indian Institute of Technology Madras, Chennai 600 036 (India); Arout Chelvane, J. [Defence Metallurgical Research Laboratory, Hyderabad 500 058 (India); Quezado, S.; Malik, S.K. [Departamento de F’ısica Teorica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59072-970 (Brazil); Nirmala, R., E-mail: nirmala@physics.iitm.ac.in [Department of Physics, Indian Institute of Technology Madras, Chennai 600 036 (India)

    2017-07-01

    Highlights: • Melt-spinning yields microcrystalline RNi (R = Gd, Tb and Ho) samples with texture. • The texture-induced anisotropy affects magnetic and magnetocaloric properties. • Melt-spinning helps one engineer magnetocaloric effect in rare-earth compounds. - Abstract: Magnetocaloric effect (MCE) in RNi (where R = Gd, Tb and Ho) compounds has been studied in their arc-melted and melt-spun forms. The compound GdNi has the orthorhombic CrB-type structure (Space group Cmcm, No. 63) and the compound HoNi has the orthorhombic FeB-type structure (Space group Pnma, No. 62) at room temperature regardless of their synthesis condition. However, arc-melted TbNi orders in a monoclinic structure (Space group P2{sub 1}/m, No. 11) and when it is rapidly quenched to a melt-spun form, it crystallizes in an orthorhombic structure (Space group Pnma, No. 62). The arc-melted GdNi, TbNi and HoNi compounds order ferromagnetically at ∼69 K, ∼67 K and ∼36 K (T{sub C}) respectively. While the melt-spun GdNi shows about 6 K increase in T{sub C}, the ordering temperature of TbNi remains nearly the same in both arc-melted and melt-spun forms. In contrast, a reduction in T{sub C} by about 8 K is observed in melt-spun HoNi, when compared to its arc-melted counterpart. Isothermal magnetic entropy change, ∆S{sub m}, calculated from the field dependent magnetization data indicates an enhanced relative cooling power (RCP) for melt-spun GdNi for field changes of 20 kOe and 50 kOe. A lowered RCP value is observed in melt-spun TbNi and HoNi. These changes could have resulted from the competing shape anisotropy and the granular microstructure induced by the melt-spinning process. Tailoring the MCE of rare earth intermetallic compounds by suitably controlled synthesis techniques is certainly one of the directions to go forward in the search of giant magnetocaloric materials.

  17. Evaluating x-ray detectors for radiographic applications: A comparison of nSCdS:Ag with Gd sub 2 O sub 2 S:Tb and Y sub 2 O sub 2 S:Tb screens

    CERN Document Server

    Kandarakis, I; Panayiotakis, G S; Nomicos, C D

    1997-01-01

    ZnSCdS:Ag was evaluated as a radiographic image receptor and was compared with Gd sub 2 O sub 2 S:Tb and Y sub 2 O sub 2 S:Tb phosphors often used in radiography. The valuation of a radiographic receptor was modelled as a three-step process: i) determination of light output intensity as related to the input radiation dose, (ii) determination of visible light characteristics with respect to radiographic optical detectors, and (iii) determination of image information transfer efficiency. The light intensity emitted per unit of x-ray exposure rate was measured and theoretically calculated for laboratory prepared screens with coating thicknesses from 20 to 220 mg cm sup - sup 2 and tube voltages rom 50 to 250 kVp. ZnSCdS:Ag light intensity was higher than that of d sub 2 O sub 2 S:Tb or Y sub 2 O sub 2 S:Tb for tube voltages less than 70 and 80 kVp respectively. ZnSCdS:Ag displayed the highest x-ray to light conversion efficiency (0.207) and had optical properties close to those of Gd sub 2 O sub 2 S:Tb nd Y sub ...

  18. Luminescent GdVO{sub 4}:Sm{sup 3+} quantum dots enhance power conversion efficiency of bulk heterojunction polymer solar cells by Förster resonance energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Bishnoi, Swati [CSIR-Network of Institutes for Solar Energy, New Delhi 110001 (India); Luminescent Materials and Devices Group, CSIR-National Physical Laboratory, New Delhi 110012 (India); Academy of Scientific and Innovative Research (AcSIR), CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Gupta, Vinay, E-mail: drvinaygupta@netscape.net; Sharma, Gauri D.; Chand, Suresh [CSIR-Network of Institutes for Solar Energy, New Delhi 110001 (India); Organic and Hybrid Solar Cells Group, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, New Delhi 110012 (India); Sharma, Chhavi; Kumar, Mahesh [Ultrafast Optoelectronics and Terahertz Photonics Lab, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, New Delhi 110012 (India); Haranath, D. [CSIR-Network of Institutes for Solar Energy, New Delhi 110001 (India); Luminescent Materials and Devices Group, CSIR-National Physical Laboratory, New Delhi 110012 (India); Naqvi, Sheerin [Luminescent Materials and Devices Group, CSIR-National Physical Laboratory, New Delhi 110012 (India)

    2016-07-11

    In this work, we report enhanced power conversion efficiency (PCE) of bulk heterojunction polymer solar cells by Förster resonance energy transfer (FRET) from samarium-doped luminescent gadolinium orthovanadate (GdVO{sub 4}:Sm{sup 3+}) quantum dots (QDs) to polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) polymer. The photoluminescence emission spectrum of GdVO{sub 4}:Sm{sup 3+} QDs overlaps with the absorption spectrum of PTB7, leading to FRET from GdVO{sub 4}:Sm{sup 3+} to PTB7, and significant enhancements in the charge-carrier density of excited and polaronic states of PTB7 are observed. This was confirmed by means of femtosecond transient absorption spectroscopy. The FRET from GdVO{sub 4}:Sm{sup 3+} QDs to PTB7 led to a remarkable increase in the power conversion efficiency (PCE) of PTB7:GdVO{sub 4}:Sm{sup 3+}:PC{sub 71}BM ([6,6]-phenyl-C{sub 71}-butyric acid methyl ester) polymer solar cells. The PCE in optimized ternary blend PTB7:GdVO{sub 4}:Sm{sup 3+}:PC{sub 71}BM (1:0.1:1.5) is increased to 8.8% from 7.2% in PTB7:PC{sub 71}BM. This work demonstrates the potential of rare-earth based luminescent QDs in enhancing the PCE of polymer solar cells.

  19. 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.

  20. The Effect of Tb and Sm Ions on the Photochromic Behavior of Two Spiropyrans of Benzoxazine Series in Solution

    Directory of Open Access Journals (Sweden)

    Esam Bakeir

    2008-01-01

    Full Text Available The photochromism of [7′-hydroxy-8′-formyl-3-methyl-4-oxospiro[1,3-benzoxazin-2,2′-[2H-1]benzopyran],SP(I,[7′-hydroxy-8′-formyl-3-benzyl-4-oxospiro[1,3-benzoxazin-2,2′-[2H-1]benzopyran] SP(II and their coordination with Tb3+and Sm3+ ions have been studied in DMF. UV/vis induced-color development due to heterolytic bond cleavage of SP(I and SP(II is greatly influenced by complexation with the lanthanide ions. The irradiation-induced color enhancement due to ring opening and thermal decoloration of the open forms of SP(I, SP(II follows first-order kinetics. Physical characteristics of the studied systems such as colorability and relaxation time of thermal bleaching parameters were determined. Moreover, light-energy transfer-induced luminescence of lanthanide ions via coordination with the two spirobenzoxazines was monitored.

  1. 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.

  2. Competing exchange interactions and their relevance for the magnetisation process in RMn6-xCrxSn6 powders (R=Y, Gd, Tb, Dy, Ho, Er)

    International Nuclear Information System (INIS)

    Brabers, J.H.V.J.; Zhou, G.F.; Colpa, J.H.P.; Buschow, K.H.J.; De Boer, F.R.

    1994-01-01

    The free-powder magnetisation of RMn 6-x Cr x Sn 6 compounds has been measured for compounds with R=Y, Gd, Tb, Dy, Ho, Er in fields up to 38 T, and interpreted in terms of a simple model, which is also outlined in this paper. From the measurements, estimates for the R-3d mean-field coupling constant (n RT ) could be derived for the cases where R=Gd, Tb, Dy, Ho, Er. In turn, the n RT values can be related to the microscopic spin-coupling constant (J RT ). In the case of YMn 6 Sn 6 the high-field measurement presents evidence for a very weak antiferromagnetic coupling between the Mn layers. Furthermore, values for the Mn moments (μ Mn ) were also derived from the magnetisation measurements. The estimated μ Mn values are of the order of 2.0 μ B . ((orig.))

  3. 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)

  4. Radioluminescence studies of colloidal oleate-capped β-Na(Gd,Lu)F4:Ln3+ nanoparticles (Ln = Ce, Eu, Tb).

    Science.gov (United States)

    Cooper, Daniel R; Capobianco, John A; Seuntjens, Jan

    2018-04-26

    We report on the synthesis, characterization, and radioluminescence quantification of several new varieties of nanoparticles with the general composition β-NaLnF4, incorporating known luminescent activator/sensitizer pairs. Using Monte Carlo modeling to complement luminescence measurements, we have calculated the radioluminescence yields and intrinsic conversion efficiencies of colloidally-dispersed nanoparticles by comparison to an organic liquid scintillator. While five of the compositions had low to modest radioluminescence yields relative to bulk materials, colloidal β-Na(Lu0.65Gd0.2Tb0.15)F4 displayed a strong output of 39 460 photons per MeV absorbed, comparable to some of the best non-hygroscopic bulk crystal scintillators and X-ray phosphors such as Gd2O2S:Tb. Measurements of β-Na(Lu0.65Gd0.2Tb0.15)F4 powder samples revealed persistent luminescence as well as stable charge trapping, warranting further investigation.

  5. Morphotropic phase boundary and magnetoelastic behaviour in ferromagnetic Tb{sub 1−x}Gd{sub x}Fe{sub 2} system

    Energy Technology Data Exchange (ETDEWEB)

    Adil, Murtaza; Yang, Sen, E-mail: yang.sen@mail.xjtu.edu.cn; Mi, Meng; Zhou, Chao, E-mail: zhouch1982@gmail.com; Wang, Jieqiong; Zhang, Rui; Liao, Xiaoqi; Wang, Yu; Ren, Xiaobing; Song, Xiaoping, E-mail: xpsong@mail.xjtu.edu.cn [School of Sciences, Frontier Institute of Science and Technology, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behaviour of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Ren, Yang [X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2015-03-30

    Morphotropic phase boundary (MPB), separating two ferroic phases of different crystal symmetries, has been studied extensively for its extraordinary enhancement of piezoelectricity in ferroelectrics. Based on the same mechanism, we have designed a magnetic MPB in the pseudobinary ferromagnetic system of Tb{sub 1−x}Gd{sub x}Fe{sub 2} and the corresponding crystal structure, magnetic properties, and magnetostriction are explored. With the synchrotron x-ray diffractometry, the structure symmetry of TbFe{sub 2}-rich compositions is detected to be rhombohedral (R) and that of GdFe{sub 2}-rich compositions is tetragonal (T) below T{sub c}. With the change of concentration, the value of magnetostriction of the samples changes monotonously, while the MPB composition Tb{sub 0.1}Gd{sub 0.9}Fe{sub 2}, which corresponds to the coexistence of R and T phases, exhibits the maximum magnetization among all available compositions and superposition of magnetostriction behaviour of R and T phases. Our result of MPB phenomena in ferromagnets may provide an effective route to design functional magnetic materials with exotic properties.

  6. A study on the photographic characteristics related to the morphology of phosphor layers in the ca wo4 and gd2o2s : Tb screen

    International Nuclear Information System (INIS)

    Lee, In Ja; Huh, Joon

    1993-01-01

    Recently, various screen film system have been introduced in diagnostic radiology. There are two kinds of screen film system : blue emitting Ca WO 4 screen has been largely used in these days. However, it tends to be changed to use green emitting Gd 2 O 2 S : Tb screen. In this study, photographic characteristics of Ca WO 4 , and Gd 2 O 2 S : Tb screen were investigated with luminescence, spectroscopy. The morphology of Ca WO 4 , and Gd 2 O 2 S : Tb were also observed by using scanning electron microscope. The result obtained were as follows: 1. There was small difference in the thickness of phosphor layers for the front and back screen of blue emitting system, but little difference in those of green emitting system. 2. There was no difference in the size of phosphor particles between the front and back screen for each screen. However, the particle size was different for the various kinds of screens. 3. The shape of phosphor particle was round with many faces for all the screens. 4. In the exposure of X - ray with the same intensity, luminescent intensity of a green emitting system was 6∼7 times larger than that of a blue emitting system. 5. The thickness of phosphor layers does not affect on the sensitivity of the screens exposed by X - ray

  7. Nuclear magnetic resonance study of (Y[sub 1-x]R[sub x])[sub 2]Co[sub 14]B compounds (R=Gd, Tb)

    Energy Technology Data Exchange (ETDEWEB)

    Myojin, T. (Takamatsu National Coll. of Technology, Takamatsu (Japan)); Hayashi, M. (Takamatsu Coll. (Japan)); Ohno, T. (Faculty of Engineering, Tokushima Univ. (Japan)); Imaeda, Y. (Faculty of Engineering, Tokushima Bunri Univ., Shido (Japan)); Ushida, T. (Faculty of Engineering, Tokushima Bunri Univ., Shido (Japan)); Tsujimura, A. (Faculty of Engineering, Tokushima Bunri Univ., Shido (Japan)); Hihara, T. (Faculty of Integrated Arts and Sciences, Hiroshima Univ. (Japan))

    1993-03-15

    Influence of the Gd spin on the Co hyperfine field has been studied by [sup 59] Co nuclear magnetic resonance (NMR) in (Y[sub 1-x]Gd[sub x])[sub 2]Co[sub 14]B compounds. It is shown that the hyperfine coupling constants from the Gd spin for 8j[sub 1] and 8j[sub 2] sites are negative while those for 16k[sub 1] and 16k[sub 2] sites are positive. The dependence of the spin orientation temperature on the non-magnetic Y concentration in (Y[sub 1-x]Tb[sub x])[sub 2]Co[sub 14]B is also investigated by magnetization and [sup 59]Co NMR measurements. A spin phase diagram for this compound is proposed. (orig.)

  8. Family of defect-dicubane Ni4Ln2 (Ln = Gd, Tb, Dy, Ho) and Ni4Y2 complexes: rare Tb(III) and Ho(III) examples showing SMM behavior.

    Science.gov (United States)

    Zhao, Lang; Wu, Jianfeng; Ke, Hongshan; Tang, Jinkui

    2014-04-07

    Reactions of Ln(III) perchlorate (Ln = Gd, Tb, Dy, and Ho), NiCl2·6H2O, and a polydentate Schiff base resulted in the assembly of novel isostructural hexanuclear Ni4Ln2 complexes [Ln = Gd (1), Tb (2), Dy (3), Ho (4)] with an unprecedented 3d-4f metal topology consisting of two defect-dicubane units. The corresponding Ni4Y2 (5) complex containing diamagnetic Y(III) atoms was also isolated to assist the magnetic studies. Interestingly, complexes 2 and 3 exhibit SMM characteristics and 4 shows slow relaxation of the magnetization. The absence of frequency-dependent in-phase and out-of-phase signals for the Ni-Y species suggests that the Ln ions' contribution to the slow relaxation must be effectual as previously observed in other Ni-Dy samples. However, the observation of χ″ signals with zero dc field for the Ni-Tb and Ni-Ho derivatives is notable. Indeed, this is the first time that such a behavior is observed in the Ni-Tb and Ni-Ho complexes.

  9. Preparation and studies of Eu3+ and Tb3+ co-doped Gd2O3 and Y2O3 sol-gel scintillating films

    International Nuclear Information System (INIS)

    Morales Ramirez, A. de J; Garcia Murillo, A.; Carrillo Romo, F. de J; Ramirez Salgado, J.; Le Luyer, C.; Chadeyron, G.; Boyer, D.; Moreno Palmerin, J.

    2009-01-01

    Eu 3+ (2.5 at.%) and Tb 3+ (0.005-0.01 at.%) co-doped gadolinium and yttrium oxide (Gd 2 O 3 and Y 2 O 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 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 3+ ) and 24 nm ± 3.0 (B = 0.01 Tb 3+ ). After treatment at 700 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 3+ - and Tb 3+ -doped Gd 2 O 3 and Y 2 O 3 powders showed that Tb 3+ contents of 0.005, 0.0075 and 0.01 at.% affected their optical properties. Lower Tb 3+ concentrations (down to 0.005 at.%) in both systems enhanced the light yield.

  10. Rare earth chalcogels NaLnSnS{sub 4} (Ln = Y, Gd, Tb) for selective adsorption of volatile hydrocarbons and gases

    Energy Technology Data Exchange (ETDEWEB)

    Edhaim, Fatimah; Rothenberger, Alexander [Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

    2017-08-16

    The synthesis and characterization of the rare earth chalcogenide aerogels NaYSnS{sub 4}, NaGdSnS{sub 4}, and NaTbSnS{sub 4} is reported. Rare earth metal ions like Y{sup 3+}, Gd{sup 3+}, and Tb{sup 3+} react with the chalcogenide clusters [SnS{sub 4}]{sup 4-} in aqueous formamide solution forming extended polymeric networks by gelation. Aerogels obtained after supercritical drying have BET surface areas of 649 m{sup 2}.g{sup -1} (NaYSnS{sub 4}), 479 m{sup 2}.g{sup -1} (NaGdSnS{sub 4}), and 354 m{sup 2}.g{sup -1} (NaTbSnS{sub 4}). Electron microscopy and physisorption studies reveal that the new materials have pores in the macro (above 50 nm) and meso (2-50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO{sub 2} over CH{sub 4} or H{sub 2}. The notable adsorption capacity for toluene (NaYSnS{sub 4}: 1108 mg.g{sup -1}; NaGdSnS{sub 4}: 921 mg.g{sup -1}; and NaTbSnS4: 645 mg.g{sup -1}) and high selectivity for gases (CO{sub 2}/H{sub 2}: 172 and CO{sub 2}/CH{sub 4}: 50 for NaYSnS{sub 4}, CO{sub 2}/H{sub 2}: 155 and CO{sub 2}/CH{sub 4}: 37 for NaGdSnS{sub 4}, and CO{sub 2}/H{sub 2}: 75 and CO{sub 2}/CH{sub 4}: 28 for NaTbSnS{sub 4}) indicate potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Color-tunable and white luminescence properties via energy transfer in single-phase KNaCa2(PO4)2:A (A = Ce3+, Eu2+, Tb3+, Mn2+, Sm3+) phosphors.

    Science.gov (United States)

    Geng, Dongling; Shang, Mengmeng; Zhang, Yang; Lian, Hongzhou; Lin, Jun

    2013-12-02

    A series of single-phase phosphors based on KNaCa2(PO4)2 (KNCP):A (A = Ce(3+), Eu(2+), Tb(3+), Mn(2+), Sm(3+)) have been prepared via the Pechini-type sol-gel method. Photoluminescence (PL) and cathodoluminescence (CL) properties of Ce(3+)-, Eu(2+)-, Tb(3+)-, Mn(2+)-, and Sm(3+)-activated KNCP phosphors were investigated. For the A singly doped KNCP samples, they exhibit the characteristic emissions of the A activator. Na(+) ions exhibit the best charge compensation result among Li(+), Na(+), and K(+) ions for Ce(3+)-, Tb(3+)-, and Sm(3+)-doped KNCP samples. The energy transfers from Ce(3+) to Tb(3+) and Mn(2+) ions as well as Eu(2+) to Tb(3+) and Mn(2+) have been validated. The emission colors of KNCP:Ce(3+)/Eu(2+), Tb(3+)/Mn(2+), Na(+) samples can be adjusted by energy transfer process and changing the Tb(3+)/Mn(2+) concentration. More importantly, white light emission in KNCP:Eu(2+), Mn(2+) system has been obtained. The KNCP:Tb(3+), Na(+) sample shows tunable luminescence from blue to cyan and then to green with the change of Tb(3+) concentration due to the cross-relaxation from (5)D3 to (5)D4. A white emission can also be realized in the single-phase KNCP host by reasonably adjusting the doping concentrations of Tb(3+) and Sm(3+) (reddish-orange emission) under low-voltage electron beam excitation. Additionally, the temperature-dependent PL properties of as-prepared phosphors reveal that the KNCP host has good thermal stability. Therefore, the KNCP:A (A = Ce(3+), Eu(2+), Tb(3+), Mn(2+), Sm(3+)) phosphors could be regarded as good candidates for UV W-LEDs and FEDs.

  12. Investigation of local magnetism in RZn (R = Ce, Gd, Tb, Dy) and GdCu intermetallic compounds using perturbed angular correlation gamma-gamma spectroscopy; Investigacao do magnetismo local em compostos intermetalicos do tipo RZn (R = Ce, Gd, Tb, Dy) e GdCu pela espectroscopia de correlacao angular gama-gama perturbada

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Brianna Bosch dos

    2010-07-01

    This work presents, from a microscopic point of view, a systematic study of the local magnetism in RZn (R = Ce, Gd, Tb, Dy) and GdCu intermetallic compounds through measurements of hyperfine interactions using the Perturbed Angular Correlation Gamma- Gamma Spectroscopy technique with {sup 111}In {yields} {sup 111}Cd and {sup 140}La {yields} {sup 140}Ce as probe nuclei. As the magnetism in these compounds originates from the 4f electrons of the rare-earth elements it is interesting to observe in a systematic study of RZn compounds the behavior of the magnetic hyperfine field with the variation of the number of 4f electrons in the R element. The use of probe nuclei {sup 140}La {yields} {sup 140}Ce is interesting because Ce{sup +3} ion posses one 4f electron which may contribute to the total hyperfine field, and the results showed anomalous behavior. The results for {sup 111}Cd probe showed that the temperature dependence of the magnetic hyperfine field follows the Brillouin function, and the magnetic hyperfine field decreases linearly with increase of the atomic number of rare earth when plotted as a function of the rare-earth J spin projection, showing that the main contribution to the magnetic hyperfine field in RZn compounds comes from the polarization of the conduction electrons. The results for the electric field gradient measured with {sup 111}Cd for all compounds showed a strong decrease with the atomic number of the rare-earth element. We have therefore assumed that the major contribution to the electric field gradient originates from the 4f electrons of the rare-earths. The measurements of the electric field gradient for GdCu with {sup 111}Cd, after temperature decreases and increases again showed that two different structures, CsCl-type cubic and FeB-type orthorhombic structures co-exist. Finally, it is the first time that measurements of hyperfine parameters have been carried out with theses two probe nuclei in the studied RZn. (author)

  13. 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

  14. Microstructural analyses and critical current densities in the high-Tc superconductor system ReBa2Cu3OX, with RE = Y, Sm, Eu, Gd, Dy, Ho

    International Nuclear Information System (INIS)

    Schindler, G.; Seebacher, B.

    1989-01-01

    The authors report on investigations into the impact of the rare earths (RE) as given in the title on the ceramic microstructure and the critical current density j c in the superconductor system REBa 2 Cu 3 O x . With RE = Sm, Eu, or Gd, the material is homogeneous in phase and crystallizes in platelets with maximum sizes of up to 350 μm. Material with RE = Y, Dy, or Ho exhibits grain sizes up to 500 μm, and a low amount of phase inhomogeneities. The critical currents measured are between 25 Acm -2 and 290 Acm -2 at 77 K, without external field. The highest values are found in systems with RE = Eu or Gd. (orig.) [de

  15. 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.

  16. 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)

  17. RE{sub 3}Au{sub 5}Zn (RE = Y, Sm, Gd-Ho). A new structure type with five- and six-membered rings as building units in a gold network

    Energy Technology Data Exchange (ETDEWEB)

    Gerke, Birgit; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie and NRW Graduate School of Chemistry

    2016-08-01

    RE{sub 3}Au{sub 5}Zn (RE = Y, Sm, Gd-Ho) intermetallic compounds were synthesized by melting the elements in sealed tantalum tubes. They exhibit a new structure type which was studied by X-ray diffraction on powders and refined from single crystal diffraction data: Cmcm, a = 736.9(2), b = 1489.4(2), c = 1330.4(3) pm, wR2 = 0.0371, 1184 F{sup 2} values and 55 variables for Y{sub 3}Au{sub 4.92}Zn{sub 1.08} and a = 739.0(1), b = 1495.8(2), c = 1339.2(2) pm, wR2 = 0.0325, 1410 F{sup 2} values and 54 variables for Tb{sub 3}Au{sub 5}Zn. The network consists of five- and six-membered gold rings in puckered conformations. Atoms of the rare earth elements are placed within the cavities of this network where every third cavity is filled by a Zn{sub 2} dumbbell. The structure is discussed in detail and compared with the gold substructure of Hf{sub 7}Au{sub 10}.

  18. 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.

  19. In vivo measurements of daily UV exposure of human anterior teeth using CaF{sub 2}:Tb,Sm as a thermoluminescence dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Saito, W., E-mail: saito-wataru@tsurumi-u.ac.j [Department of Operative Dentistry, Tsurumi University, School of Dental Medicine, 2-1-3, Tsurumi, Tsurumi-ku, Yokohama (Japan); Ikejima, I. [Department of Operative Dentistry, Tsurumi University, School of Dental Medicine, 2-1-3, Tsurumi, Tsurumi-ku, Yokohama (Japan); Fukuda, Y. [Department of Urban Environment, Faculty of Human Environment, Osaka Sangyo University, 3-1-1, Nakagaito, Daito, Osaka (Japan); Momoi, Y. [Department of Operative Dentistry, Tsurumi University, School of Dental Medicine, 2-1-3, Tsurumi, Tsurumi-ku, Yokohama (Japan)

    2011-03-15

    Ultraviolet radiation (UV) has been indicated as one of the causes of discoloration of dental materials yet the standard requires that dental polymers be irradiated with light from a xenon lamp, which includes UV, to evaluate their color stability. It is doubtful that dental polymers in the mouth are exposed to large energy of UV on a daily basis, but there have been no reports concerning exposure. In the present study, we used thermoluminescence (TL) from sintered CaF{sub 2}:Tb,Sm, which is highly sensitive to UV, to measure the daily energy of UV exposure to the labial surface of the maxillary anterior teeth, which are regarded as receiving the maximum exposure among oral tissues. We produced disks of CaF{sub 2} co-doped with Tb{sub 4}O{sub 7} and Sm{sub 2}O{sub 3} (sintered CaF{sub 2}:Tb,Sm) that were 5 mm in diameter and 1 mm thick, and placed them inside glass cases that had a 7-mm external diameter, 3-mm height, and 1-mm thickness of glass made of synthetic silica with {>=}90% UV transmittance. These glass cases were fixed in dental mouthpieces in a position corresponding to the central maxillary incisors. These mouthpieces were worn by 11 subjects and UV measurements were carried out over a 24-h period in a uniform environment. The results of these TL measurements showed a TL glow peak in the region of 430 K. This was the same as that seen with irradiation from a xenon lamp as basic illumination. The daily UV radiant energy was 72.2 mJ/cm{sup 2} (32.7-143.8 mJ/cm{sup 2}), calculated from the relationship between TL intensity and UV radiant energy. This corresponded to 0.02% of the UV radiant energy contained in the light irradiation specified by ISO 4049.

  20. 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.

  1. Transport properties in amorphous U/sub x/-T1/sub -//sub x/ films (T = Fe, Ni, Gd, Tb, and Yb) (invited)

    International Nuclear Information System (INIS)

    Freitas, P.P.; Plaskett, T.S.; Moreira, J.M.; Amaral, V.S.

    1988-01-01

    We describe the competing magnetic, localization, and phonon effects on the transport properties of amorphous magnetic U/sub x/T/sub 1-//sub x/ films, with T = Fe, Ni, Gd, Tb, and Yb. Amorphous U/sub x/Fe/sub 1-//sub x/ films change from collinear to random ferromagnetism as x increases, and the temperature dependence of the resistivity denotes the competing effects of spin-flip and non-spin-flip exchange scattering processes. The resistivity has a minimum at T/sub f/ rising sharply below this temperature. The sign of the magnetic resistivity and the magnetoresistance indicates >0, while the anisotropic magnetoresistance indicates a local exchange gap. Amorphous U/sub x/Gd/sub 1-//sub x/ and a-U/sub x/Tb/sub 1-//sub x/ are, respectively, spin glasses and random anisotropy dominated systems. The resistivity increases smoothly through T/sub f/ and has a slight upturn at low temperatures that we associate with weak localization. The magnetoresistance is negative in both systems and the anisotropic magnetoresistance is null, although the applied field induces anisotropic behavior in the Tb containing films (asperomagnets). All samples show quadratic and positive field dependence of magnetoresistance well inside the paramagnetic regime, and a linear regime below T/sub f/. At low temperatures and in the a-U/sub x/Gd/sub 1-//sub x/ films, negative (H)/sup 1/2/ and H 2 regimes occur and are associated with weak localization processes dominated by the inelastic mean free path

  2. Charge Carrier Trapping Processes in RE2O2S (RE = La, Gd, Y, and Lu)

    NARCIS (Netherlands)

    Luo, H.; Bos, A.J.J.; Dorenbos, P.

    2017-01-01

    Two different charge carrier trapping processes have been investigated in RE2O2S:Ln3+ (RE = La, Gd, Y, and Lu; Ln = Ce, Pr, and Tb) and RE2O2S:M (M = Ti4+ and Eu3+). Cerium, praseodymium and terbium act as recombination centers and hole trapping centers while host intrinsic defects provide the

  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. Isothiocyanato complexes of Gd(III), Tb(III), Dy(III) and Ho(III) with 2-(2'-pyridyl)benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, A; Singh, V K

    1982-01-01

    Six-coordinated complexes of the type (Ln(PyBzH)/sub 2/NCS.H/sub 2/O) (NCS)/sub 2/.nH/sub 2/O/mC/sub 2/H/sub 5/OH (Ln = Gd(III), Tb(III), Dy(III) and Ho(III), n=1-2; m=1) have been prepared from Ln(NCS)/sub 6//sup 3 -/. The room temperature magnetic moment values confirm the terpositive state of the lanthanide ions. Infrared spectra suggest the N-coordination of thiocyanate group. Electronic spectral studies of Tb(III), Dy(III) and Ho(III) complexes have been made in terms of LSJ term energies. 13 refs.

  5. 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.

  6. 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.

  7. Tunable luminescence properties and energy transfer of Ba{sub 3}NaLa(PO{sub 4}){sub 3}F:Tb{sup 3+},Sm{sup 3+} phosphors with apatite structure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Haikun; Liao, Libing, E-mail: clayl@cugb.edu.cn; Chen, Jian; Guo, Qingfeng; Zhang, Yuanyuan; Mei, Lefu, E-mail: mlf@cugb.edu.cn

    2016-01-15

    Tb{sup 3+}–Sm{sup 3+} co-doped Ba{sub 3}NaLa(PO{sub 4}){sub 3}F phosphors with apatite structure have been prepared by a high temperature solid-state reaction, and their luminescence properties have been investigated in detail. The energy transfer (ET) mechanism was verified as the dipole–quadrupole mechanism, and the ET efficiency as well as the critical distance is also estimated. As a result of fine-tuning of the emission composition of the Tb{sup 3+} and Sm{sup 3+} ions, tunable luminescence properties can be realized by combining the emission of Tb{sup 3+} and Sm{sup 3+} in a single host lattice under UV light excitation. The emission color of the obtained phosphors can be modulated from green to yellow by controlling the doping content of the Sm{sup 3+} ions with the fixed Tb{sup 3+} content. Additional, as the temperature increases from RT to 150 °C, the PL intensities of Ba{sub 3}NaLa{sub 0.7}(PO{sub 4}){sub 3}F:0.10Tb{sup 3+},0.20Sm{sup 3+} decreased to 80.4% and 78.6% of the initial PL intensity, corresponding to the intensity of transition of Sm{sup 3+} and transition of Tb{sup 3+} in the Ba{sub 3}NaLa{sub 0.7}(PO{sub 4}){sub 3}F:0.10Tb{sup 3+},0.20Sm{sup 3+} phosphor, respectively. These results indicate the series of Ba{sub 3}NaLa{sub 1−x−y}(PO{sub 4}){sub 3}F:xTb{sup 3+},ySm{sup 3+} phosphors can be acted as a good candidate for the application in white light-emitting diodes. - Highlights: • Tb{sup 3+},Sm{sup 3+}-codoped Ba{sub 3}NaLa(PO{sub 4}){sub 3}F phosphors have been synthesized. • The emission color of the obtained phosphors can be modulated from green to red. • This phosphor has a good thermal stability.

  8. 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.

  9. Effect of boron additions on phase formation and magnetic properties of TbCu{sub 7}-type melt spun SmFe ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Chuanjiang; Yu, Dunbo, E-mail: yudb2008@126.com; Li, Kuoshe; Luo, Yang; Jin, Jinling; Lu, Shuo; Li, Hongwei; Mao, Yongjun; Quan, Ningtao

    2016-08-15

    Melt spun ribbons of a series of SmFe{sub 12}B{sub x} (x=0.0, 0.5, 0.75, 1.0, 1.25, and 1.5) have been prepared by the melt spinning technique. Sm–Fe–B melt spun ribbons with single phase TbCu{sub 7}-type structure were prepared from the SmFe{sub 12}B{sub x} (x=0.5, 0.75, and 1.0) alloys at the surface velocity around 40 m/s. The addition of boron not only inhibits the appearance of soft magnetic phase α-Fe, but also enhances the ability of amorphous formation for melt spun Sm–Fe ribbons. The concentration of boron atoms, however, exceeds the limit of the solubility (x>1.0) of Sm–Fe alloys, which does not impede the appearance of α-Fe but accelerates the formation of metastable phase Sm{sub 2}Fe{sub 23}B{sub 3} that is unfavorable to their magnetic properties. Moreover, it is found that the addition of boron whose concentration is 0.0≤x≤0.75 can stabilize the metastable TbCu{sub 7}-type structure because of the increase of the lattice parameter ratio c/a. The magnetic properties of as-annealed SmFe{sub 12}B{sub 1.0} melt spun ribbons with an energy product of 2.19MGOe, a coercivity of 2.36 kOe and a remanence of 4.8 kGs have been achieved. The microstructural characteristics of as-annealed melt spun SmFe{sub 12} and SmFe{sub 12}B{sub 1.0} ribbons have been discussed as well. The following sequence of the hyperfine field H(6l)TbCu{sub 7}-type structure, and the

  10. Effect of boron additions on phase formation and magnetic properties of TbCu7-type melt spun SmFe ribbons

    International Nuclear Information System (INIS)

    Zheng, Chuanjiang; Yu, Dunbo; Li, Kuoshe; Luo, Yang; Jin, Jinling; Lu, Shuo; Li, Hongwei; Mao, Yongjun; Quan, Ningtao

    2016-01-01

    Melt spun ribbons of a series of SmFe 12 B x (x=0.0, 0.5, 0.75, 1.0, 1.25, and 1.5) have been prepared by the melt spinning technique. Sm–Fe–B melt spun ribbons with single phase TbCu 7 -type structure were prepared from the SmFe 12 B x (x=0.5, 0.75, and 1.0) alloys at the surface velocity around 40 m/s. The addition of boron not only inhibits the appearance of soft magnetic phase α-Fe, but also enhances the ability of amorphous formation for melt spun Sm–Fe ribbons. The concentration of boron atoms, however, exceeds the limit of the solubility (x>1.0) of Sm–Fe alloys, which does not impede the appearance of α-Fe but accelerates the formation of metastable phase Sm 2 Fe 23 B 3 that is unfavorable to their magnetic properties. Moreover, it is found that the addition of boron whose concentration is 0.0≤x≤0.75 can stabilize the metastable TbCu 7 -type structure because of the increase of the lattice parameter ratio c/a. The magnetic properties of as-annealed SmFe 12 B 1.0 melt spun ribbons with an energy product of 2.19MGOe, a coercivity of 2.36 kOe and a remanence of 4.8 kGs have been achieved. The microstructural characteristics of as-annealed melt spun SmFe 12 and SmFe 12 B 1.0 ribbons have been discussed as well. The following sequence of the hyperfine field H(6l)TbCu 7 -type structure, and the metastable phase Sm 2 Fe 23 B 3 will appear when the content of boron

  11. Critical evaluation and thermodynamic optimisation of the Si-RE systems: Part II. Si-RE system (RE = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y)

    International Nuclear Information System (INIS)

    Kim, Junghwan; Jung, In-Ho

    2015-01-01

    Highlights: • The (Si-RE) (RE = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y) systems have been reviewed. • The thermodynamic optimization of the (Si-RE) systems have been performed. • Systematic changes and similarities in the (Si-RE) systems were found. • The systematic approach resolved inconsistencies in the experimental data. • The systematic approach was used to assess the unexplored phase diagrams. - Abstract: A critical evaluation and optimisation of all available phase diagrams and thermodynamic data of the (Si-RE) (RE = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y) systems was conducted to obtain reliable thermodynamic functions of all the phases in the system. In the thermodynamic modelling, a systematic analysis involving the similarity and periodicity observed in the lanthanide series was applied to resolve inconsistencies in the experimental data and to estimate the unknown thermodynamic properties and phase equilibria data. In particular, the phase diagrams and thermodynamic properties of (Si-Tm) and (Si-Lu) systems which are rarely investigated can be predicted from this approach. Systematic trends in thermodynamic properties of solid and liquid phases and phase diagram of the entire (Si-RE) systems were summarized

  12. 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

  13. X-ray spectroscopic and magnetic studies of RBaCo_2O_5_._5, R = Pr, Nd, Sm, Gd and Y

    International Nuclear Information System (INIS)

    Ganorkar, S.; Priolkar, K. R.; Sarode, P. R.; Emura, S.

    2016-01-01

    The structural and magnetic properties of layered perovskites of the type RBaCo_2O_5_+_δ with δ ≤0.5 (R=Pr, Nd, Sm, Gd and Y) have been investigated. The samples were prepared by the sol-gel method and characterized by X-ray diffraction, magnetization and X-ray absorption near edge structure (XANES) spectroscopy. It is found that the magnetic properties depend on the size of the rare-earth ion. The critical size of the rare-earth ion introduces structural distortion which affects the Co-O hybridization in these layered perovskites. The detailed analysis of experimental and calculated XANES spectra throws some light on spin states of Co ions in these perovskites.

  14. Structural and optical properties of Tb-doped Na-Gd metaphosphate glasses and glass-ceramics

    Czech Academy of Sciences Publication Activity Database

    Moretti, F.; Vedda, A.; Nikl, Martin; Nitsch, Karel

    2009-01-01

    Roč. 21, č. 15 (2009), 155103/1-155103/7 ISSN 0953-8984 R&D Projects: GA AV ČR IAA200100626 Institutional research plan: CEZ:AV0Z10100521 Keywords : Na-Gd metaphosphate glass * glass -ceramics * NaGd(PO 3 ) 4 * optical properties * structural properties * Raman spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.964, year: 2009

  15. Optical emission, vibrational feature, and shear-thinning aspect of Tb3+-doped Gd2O3 nanoparticle-based novel ferrofluids irradiated by gamma photons

    Science.gov (United States)

    Paul, Nibedita; Hazarika, Samiran; Saha, Abhijit; Mohanta, Dambarudhar

    2013-10-01

    The present work reports on the spectroscopic and rheological properties of un-exposed and gamma (γ-) irradiated rare earth (RE) oxide nanoparticle-based ferrofluids (FFs). The FFs were produced by dispersing surfactant coated terbium (Tb3+)-doped gadolinium oxide (Gd2O3) nanoparticles in the ethanol medium and later on they were subjected to energetic γ-irradiation (1.25 MeV) at select doses (97 Gy and 2.635 kGy). The synthesized RE oxide nanoparticles were of ˜7 nm size and having a cubic crystal structure, as predicted from transmission electron microscopy and x-ray diffraction studies. Fourier transformed infra-red (FT-IR) spectra showed an adequate blue shift of the Gd-O vibrational stretching mode from a wavenumber value of ˜558 cm-1, for the un-irradiated sample to a value of ˜540 cm-1 corresponding to the irradiated sample (2.635 kGy). In contrast, photoluminescence spectra have revealed modification of defect states along with Tb3+ assisted radiative transitions. The rheology measurements have illustrated unusual shear thinning behavior of the FFs, with an apparently improved power index (s) value from 0.34 to 0.50, obtained for increasing γ-dose cases. The variation of the decay parameter with irradiation dose, as predicted from the nature of apparent viscosity curves, is attributed to the defect formation, role of impurity ions (Tb3+), and weakening of inter nanoparticle bonding. The unusual properties of the novel RE oxide based FFs may find scope in sealing and shielding elements in the radiation environment including accelerator and other related zones.

  16. Synthesis, structure and luminescence properties of binary and ternary complexes of lanthanide (Eu{sup 3+}, Sm{sup 3+} and Tb{sup 3+}) with salicylic acid and 1,10-phenanthroline

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Chen-Qi; Yan, Tian-Lu; Wang, Yi-Ting; Ye, Zi-Jun; Xu, Cun-Jin, E-mail: cjxu@hznu.edu.cn; Zhou, Wen-Jun

    2017-04-15

    A series of binary and ternary complexes of lanthanide (Eu{sup 3+}, Sm{sup 3+} and Tb{sup 3+}) with salicylic acid (Hsal) and 1,10-phenanthroline (phen) were synthesized, and characterized by element analysis, coordination titration analysis, IR, UV and TG-DTA. Their compositions were (NH{sub 4})[Ln(sal){sub 4}(H{sub 2}O){sub 2}] (Ln=Eu (1), Sm (2), Tb (3)) and (NH{sub 4})[Ln(sal){sub 4}(phen){sub 2}] (Ln=Eu (4), Sm (5), Tb (6)), respectively. In particular, the ternary complex of Eu{sup 3+}, 4, was characterized by X-ray diffraction, and luminescence intensities of binary and ternary complexes were compared. In case of Eu{sup 3+} and Sm{sup 3+} complexes, ternary complexes emitted stronger luminescence than corresponding binary complexes of salicylic acid and Ln{sup 3+}. On the other hand, the ternary Tb{sup 3+} complex had weaker luminescence than the binary complex because of back energy transfer from Tb{sup 3+} to phen. The CIE coordinates of 1–6 were calculated as (0.65, 0.35), (0.52, 0.48), (0.33, 0.59), (0.67, 0.33), (0.62, 0.38) and (0.36, 0.58), respectively, which enable these complexes to be promising candidates for red, green, or yellow component in OLEDs.

  17. 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.

  18. Enhancement of CdSiO3: Tb3+ green long-lasting phosphors by co-doping with Re3+ (Re3+=Gd3+, Y3+, La3+) ions

    International Nuclear Information System (INIS)

    Zeng, Wei; Wang, Yuhua; Han, Shaochun; Chen, Wenbo; Li, Gen

    2014-01-01

    CdSiO 3 : Tb 3+ , Re 3+ long-lasting phosphors were synthesized by the conventional high temperature solid-state method. A green-light phosphorescence phenomenon, which was associated with the 5 D 4 → 7 F J (J=6, 5, 4, 3) transitions of the Tb 3+ ion, was observed. Introduction of Re 3+ (Re 3+ =Gd 3+ , Y 3+ , La 3+ ) ions, which deepens the depth (E t ) or/and increases the density (n 0 ) of traps, greatly improved the afterglow properties of CdSiO 3 : Tb 3+ . Possible mechanism of CdSiO 3 : Tb 3+ , Re 3+ was discussed in this work. - Highlights: • CdSiO 3 : Tb 3+ , Re 3+ samples enrich the color of long-lasting afterglow phosphors in CdSiO 3 host. • Both the afterglow intensity and the lasting time are greatly enhanced for the co-doped samples, especially for Cd 0.96 SiO 3 : Tb 0.03 3+ , La 0.01 3+ . • Introduction of Re 3+ (Re 3+ =Gd 3+ , Y 3+ , La 3+ ) ions, which deepens the depth (E t ) or increase density(n 0 ) of traps, greatly improved the afterglow properties of CdSiO 3 : Tb 3+

  19. Color tunable emission in Ce3+ and Tb3+ co-doped Ba2Ln(BO3)2Cl (Ln=Gd and Y) phosphors for white light-emitting diodes.

    Science.gov (United States)

    Zhang, Niumiao; Guo, Chongfeng; Jing, Heng; Jeong, Jung Hyun

    2013-12-01

    Ce(3+) and Tb(3+) co-doped Ba2Ln(BO3)2Cl (Ln=Y and Gd) green emitting phosphors were prepared by solid state reaction in reductive atmosphere. The emission and excitation spectra as well as luminescence decays were investigated, showing the occurrence of efficient energy transfer from Ce(3+) to Tb(3+) in this system. The phosphors exhibit both a blue emission from Ce(3+) and a green emission from Tb(3+) under near ultraviolet light excitation with 325-375 nm wavelength. Emission colors of phosphors could be tuned from deep blue through cyan to green by adjusting the Tb(3+) concentrations. The energy transfer efficiency and emission intensity of Ba2Y(BO3)2Cl:Ce(3+), Tb(3+) precede those of Ba2Gd(BO3)2Cl:Ce(3+), Tb(3+), and the sample Ba2Y(BO3)2Cl:0.03Ce(3+), 0.10Tb(3+) is the best candidate for n-UV LEDs. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Synthesis and photoluminescence characteristics of (Y,Gd)BO3:RE (RE = Eu(3+), Ce(3+), Dy(3+) and Tb(3+)) phosphors for blue chip and near-UV white LEDs.

    Science.gov (United States)

    Rangari, V V; Singh, V; Dhoble, S J

    2016-03-01

    A series of Eu(3+)-, Ce(3+)-, Dy(3+)- and Tb(3+)-doped (Y,Gd)BO3 phosphors was synthesized by a solid-state diffusion method. X-Ray diffraction confirmed their hexagonal structure and the scanning electron microscopy results showed crystalline particles. The excitation spectra revealed that (Y,Gd)BO3 phosphors doped with Eu(3+), Ce(3+), Dy(3+) and Tb(3+) are effectively excited with near UV-light of 395 nm/blue light, 364, 351 and 314 nm, respectively. Photoluminescence spectra of Eu(3+)-, Ce(3+)- and Tb(3+)/Dy(3+)-doped phosphor showed intense emission of reddish orange, blue and white light, respectively. The phosphor Y0.60Gd0.38BO3:Ce0.02 showed CIE 1931 color coordinates of (0.158, 0.031) and better color purity compared with commercially available blue BAM:Eu(2+) phosphor. The phosphor (Y,Gd)BO3 doped with Eu(3+), Dy(3+) and Tb(3+) showed CIE 1931 color coordinates of (0.667, 0.332), (0.251, 0.299) and (0.333, 0.391) respectively. Significant photoluminescence characteristics of the prepared phosphors indicate that they might serve as potential candidates for blue chip and near-UV white light-emitting diode applications. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Fabrication and characterization of pixelated Gd{sub 2}O{sub 2}S:Tb scintillator screens for digital X-ray imaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongyul, E-mail: kjongyul@kaist.ac.kr [Korea Advanced Institute of Science and Technology, 335 Gwahangno, Daejeon 305-701 (Korea, Republic of); Kyoung Cha, Bo; Hyung Bae, Jun; Lee, Chae-hun; Kim, Hyungtaek; Chang, Sungho; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, 335 Gwahangno, Daejeon 305-701 (Korea, Republic of); Sim, Cheulmuu; Kim, Taejoo [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Daejeon 305-353 (Korea, Republic of)

    2011-05-15

    X-ray imaging detectors in combination with scintillator screens have been widely used in digital X-ray imaging applications. Gd{sub 2}O{sub 2}S:Tb was used as scintillation material for pixelated scintillator screens based on silicon substrates (wafer) with a micropore array of various dimensions fabricated using the photolithography and deep reactive ion etching (DRIE) process. The relative light output and the modulation transfer function (MTF) of each fabricated scintillator screen were measured by a cooled CCD and compared with those of Lanex screens. The spatial resolution of our scintillator screens was higher but their light outputs were lower than those of Lanex screen probably due to the loss of light at the wall surfaces. Therefore further treatment of the wall surface, such as reflective coating, seems necessary to compensate the light loss.

  2. Effects of pressure and magnetic field on transport properties of Y1-xRxCo2 alloys (R=Gd, Tb, Dy, Ho and Er)

    International Nuclear Information System (INIS)

    Takaesu, Y; Nakama, T; Kinjyo, A; Yonamine, S; Hedo, M; Yagasaki, K; Uchima, K; Uwatoko, Y; Burkov, A T

    2010-01-01

    Electrical resistivity ρ and thermopower S of Y 1-x R x Co 2 (R=Gd, Tb, Dy, Ho and Er) Laves phase alloy systems were measured at temperatures from 1.5 K to 300 K in magnetic fields up to 15 T and under hydrostatic pressure up to 2 GPa. We show that there is a universal linear relation between the pressure and magnetic field derivatives of the resistivity, dρ/dP and dρ/dB, with gradient, determined by pressure derivative of the critical metamagnetic field of the cobalt 3d electron system. A similar scaling behavior was found for the thermopower dependencies on pressure and alloy composition.

  3. 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)

  4. Tunable luminescence and energy transfer properties in Na{sub 3}Bi(PO4){sub 2}:Eu{sup 3+}, Tb{sup 3+}, Dy{sup 3+}, Sm{sup 3+} phosphors with high thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zizhong; Fu, Guangsheng; Yang, Yong; Yang, Zhiping, E-mail: yangzp2005@sohu.com; Li, Panlai, E-mail: li_panlai@126.com

    2017-04-15

    Na{sub 3}Bi(PO{sub 4}){sub 2}:Eu{sup 3+}/Tb{sup 3+}/Dy{sup 3+}/Sm{sup 3+} phosphors were synthesized via a high-temperature solid-state reaction method. The X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), diffuse reflection, photoluminescence (PL) and fluorescent decay curves were utilized to characterize the obtained phosphors. Under n-UV excitation, Na{sub 3}Bi(PO{sub 4}){sub 2}:Eu{sup 3+}/Tb{sup 3+}/Dy{sup 3+}/Sm{sup 3+} samples show the characteristic f-f emissions and present red, green, yellow and orange emission, respectively. When Tb{sup 3+}, Dy{sup 3+} and Sm{sup 3+} were co-doped into the Na{sub 3}Bi(PO{sub 4}){sub 2}:Eu{sup 3+} phosphors, tunable emission colors can be obtained and can be efficiently adjusted by varying the doping ions and the doping concentration. The energy transfer mechanisms were investigated in detail and demonstrated that there is an efficient energy transfer from Tb{sup 3+}, Dy{sup 3+} and Sm{sup 3+} to Eu{sup 3+} via a dipole-dipole interaction mechanism. Additional, as the temperature increases from RT to 150 °C, the PL intensity of Tb{sup 3+}-Eu{sup 3+}, Dy{sup 3+}-Eu{sup 3+} and Sm{sup 3+}-Eu{sup 3+} co-doped phosphors decreased to 86%, 85% and 88%, respectively, which prove good thermal stability. All the CIE coordinates of as-prepared phosphors are displayed and show abundant colors, making these materials have potential applications for n-UV-excited white-LEDs.

  5. Folic acid-conjugated GdPO{sub 4}:Tb{sup 3+}@SiO{sub 2} Nanoprobe for folate receptor-targeted optical and magnetic resonance bi-modal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xianzhu [Jiangxi Normal University, College of Life Science, Jiangxi Provincial Key Laboratory of Protection and Utilization of Subtropical Plant Resources of Jiangxi Province (China); Zhang, Xiaoying; Wu, Yanli, E-mail: Wanny118@126.com [Jiangxi Science and Technology Normal University, Jiangxi Key Laboratory of Organic Chemistry (China)

    2016-11-15

    Both fluorescent and magnetic nanoprobes have great potential applications for diagnostics and therapy. In the present work, a folic acid-conjugated and silica-modified GdPO{sub 4}:Tb{sup 3+} (GdPO{sub 4}:Tb{sup 3+}@SiO{sub 2}-FA) dual nanoprobe was strategically designed and synthesized for the targeted dual-modality optical and magnetic resonance (MR) imaging via a facile aqueous method. Their structural, optical, and magnetic properties were determined using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), ultraviolet-visible spectra (UV-Vis), photoluminescence (PL), and superconducting quantum interference device (SQUID). These results indicated that GdPO{sub 4}:Tb{sup 3+}@SiO{sub 2}-FA were uniform monodisperse core-shell structured nanorods (NRs) with an average length of ~200 nm and an average width of ~25 nm. The paramagnetic property of the synthesized GdPO{sub 4}:Tb{sup 3+}@SiO{sub 2}-FA NRs was confirmed with its linear hysteresis plot (M-H). In addition, the NRs displayed an obvious T{sub 1}-weighted effect and thus it could potentially serve as a T{sub 1}-positive contrast agent. The NRs emitted green lights due to the {sup 5}D{sub 4} → {sup 7}F{sub 5} transition of the Tb{sup 3+}. The in vitro assays with NCI-H460 lung cancer cells and human embryonic kidney cell line 293T cells indicated that the GdPO{sub 4}:Tb{sup 3+}@SiO{sub 2}-FA nanoprobe could specifically bind the cells bearing folate receptors (FR). The MTT assay of the NRs revealed that its cytotoxicity was very low. Further in vivo MRI experiments distinctively depict enhanced anatomical features in a xenograft tumor. These results suggest that the GdPO{sub 4}:Tb{sup 3+}@SiO{sub 2}-FA NPs have excellent imaging and cell-targeting abilities for the folate receptor-targeted dual-modality optical and MR imaging and can be potentially used as the nanoprobe for bioimaging.

  6. Formation constants of Sm(III), Dy(III), Gd(III), Pr(III) and Nd(III) complexes of tridentate schiff base, 2-[(1H-benzimidazol-2-yl-methylene) amino] phenol

    International Nuclear Information System (INIS)

    Omprakash, K.L.; Chandra Pal, A.V.; Reddy, M.L.N.

    1982-01-01

    A new tridentate schiff base, 2- (1H-benzimidazol-2-yl-methylene)amino phenol derived from benzimididazole-2-carbo-xaldehyde and 2-aminophenol has been synthesised and characterised by spectral and analytical data. Proton-ligand formation constants of the schiff base and metal-ligand formation constants of its complexes with Sm(III), Dy(III), Gd(III), Nd(III) and Pr(III) have been determined potentiometrically in 50% (v/v) aqueous dioxane at an ionic strength of 0.1M (NaClO 4 ) and at 25deg C using the Irving-Rossotti titration technique. The order of stability constants (logβ 2 ) is found to be Sm(III)>Dy(III)>Gd(III)>Pr(III)>Nd(III). (author)

  7. Formation constants of Sm(III), Dy(III), Gd(III), Pr(III) and Nd(III) complexes of tridentate schiff base, 2-((1H-benzimidazol-2-yl-methylene) amino) phenol

    Energy Technology Data Exchange (ETDEWEB)

    Omprakash, K L; Chandra Pal, A V; Reddy, M L.N. [Osmania Univ., Hyderabad (India). Dept. of Chemistry

    1982-03-01

    A new tridentate schiff base, 2- (1H-benzimidazol-2-yl-methylene)amino phenol derived from benzimididazole-2-carbo-xaldehyde and 2-aminophenol has been synthesised and characterised by spectral and analytical data. Proton-ligand formation constants of the schiff base and metal-ligand formation constants of its complexes with Sm(III), Dy(III), Gd(III), Nd(III) and Pr(III) have been determined potentiometrically in 50% (v/v) aqueous dioxane at an ionic strength of 0.1M (NaClO/sub 4/) and at 25deg C using the Irving-Rossotti titration technique. The order of stability constants (log..beta../sub 2/) is found to be Sm(III)>Dy(III)>Gd(III)>Pr(III)>Nd(III).

  8. Study of LnBaCo{sub 2}O{sub 6-d}elta (Ln = Pr, Nd, Sm and Gd) double perovskites as new cathode material for IT-SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, E; Mueller, M; Mogni, L; Caneiro, A, E-mail: mogni@cab.cnea.gov.a [Centro Atomico Bariloche-CNEA, Instituto Balseiro. Av. Bustillo 9500, S. C. de Bariloche 8400 (Argentina)

    2009-05-01

    Oxides with double perovskites structures of general composition LnBaCo{sub 2}O{sub 6-d}elta (Ln = Pr, Nd, Sm and Gd) were synthesized by solid state reaction with the purpose to evaluate new materials to be used as cathodes in intermediate temperature solid oxide fuel cell (IT-SOFC). A preliminary study about electrochemical properties was performed by impedance spectroscopy between 500 and 800 deg. C under atmosphere of pure O{sub 2}. Symmetrical cells were obtained by spray deposition of LnBaCo{sub 2}O{sub 6-d}elta (Ln = Pr, Nd, Sm and Gd) at both sides of a dense ceramic electrolyte. The impedance spectroscopy measurements as a function of temperatures show a hysteresis loop which could be associated to a tetragonal/orthorhombic phase transition. The existence of this transition was corroborated by high temperature X-Ray diffraction and Differential Scanning Calorimetry measurements.

  9. 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.

  10. 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...

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

    Science.gov (United States)

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

    2017-03-01

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

  12. 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.)

  13. Structural elucidation and magnetic behavior evaluation of rare earth (La, Nd, Gd, Tb, Dy) doped BaCoNi-X hexagonal nano-sized ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Majeed, Abdul, E-mail: abdulmajeed2276@gmail.com [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Khan, Muhammad Azhar, E-mail: azhar.khan@iub.edu.pk [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Raheem, Faseeh ur; Hussain, Altaf; Iqbal, F. [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Murtaza, Ghulam [Centre for Advanced Studies in Physics, Government College University, Lahore 54000 (Pakistan); Akhtar, Majid Niaz [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Shakir, Imran [Deanship of Scientific Research, College of Engineering, King Saud University, PO Box 800, Riyadh 11421 (Saudi Arabia); Warsi, Muhammad Farooq [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan)

    2016-06-15

    Rare-earth (RE=La{sup 3+}, Nd{sup 3+}, Gd{sup 3+}, Tb{sup 3+}, Dy{sup 3+}) doped Ba{sub 2}NiCoRE{sub x}Fe{sub 28−x}O{sub 46} (x=0.25) hexagonal ferrites were synthesized for the first time via micro-emulsion route, which is a fast chemistry route for obtaining nano-sized ferrite powders. These nanomaterials were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), as well as vibrating sample magnetometer (VSM). The XRD analysis exhibited that all the samples crystallized into single X-type hexagonal phase. The crystalline size calculated by Scherrer's formula was found in the range 7–19 nm. The variations in lattice parameters elucidated the incorporation of rare-earth cations in these nanomaterials. FTIR absorption spectra of these X-type ferrites were investigated in the wave number range 500–2400 cm{sup −1.} Each spectrum exhibited absorption bands in the low wave number range, thereby confirming the X-type hexagonal structure. The enhancement in the coercivity was observed with the doping of rare-earth cations. The saturation magnetization was lowered owing to the redistribution of rare-earth cations on the octahedral site (3b{sub VI}). The higher values of coercivity (664–926 Oe) of these nanomaterials suggest their use in longitudinal recording media. - Graphical abstract: Nano-sized rare-earth (RE=La{sup 3+}, Nd{sup 3+}, Gd{sup 3+}, Tb{sup 3+}, Dy{sup 3+}) doped Ba{sub 2}NiCoRE{sub x}Fe{sub 28−x}O{sub 46} (x=0.25) hexagonal ferrites were synthesized for the first time via micro-emulsion route and the crystallite size was found in the range 7–19 nm. The enhancement in the coercivity was observed with the doping of rare-earth cations. The higher values of coercivity (664–926 Oe) of these nanomaterials suggest their use in longitudinal recording media. - Highlights: • Micro-emulsion route was used to synthesize Ba{sub 2}NiCoRE{sub x}Fe{sub 28−x}O{sub 46} ferrites. • The crystallite size was found

  14. Structural elucidation and magnetic behavior evaluation of rare earth (La, Nd, Gd, Tb, Dy) doped BaCoNi-X hexagonal nano-sized ferrites

    International Nuclear Information System (INIS)

    Majeed, Abdul; Khan, Muhammad Azhar; Raheem, Faseeh ur; Hussain, Altaf; Iqbal, F.; Murtaza, Ghulam; Akhtar, Majid Niaz; Shakir, Imran; Warsi, Muhammad Farooq

    2016-01-01

    Rare-earth (RE=La 3+ , Nd 3+ , Gd 3+ , Tb 3+ , Dy 3+ ) doped Ba 2 NiCoRE x Fe 28−x O 46 (x=0.25) hexagonal ferrites were synthesized for the first time via micro-emulsion route, which is a fast chemistry route for obtaining nano-sized ferrite powders. These nanomaterials were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), as well as vibrating sample magnetometer (VSM). The XRD analysis exhibited that all the samples crystallized into single X-type hexagonal phase. The crystalline size calculated by Scherrer's formula was found in the range 7–19 nm. The variations in lattice parameters elucidated the incorporation of rare-earth cations in these nanomaterials. FTIR absorption spectra of these X-type ferrites were investigated in the wave number range 500–2400 cm −1. Each spectrum exhibited absorption bands in the low wave number range, thereby confirming the X-type hexagonal structure. The enhancement in the coercivity was observed with the doping of rare-earth cations. The saturation magnetization was lowered owing to the redistribution of rare-earth cations on the octahedral site (3b VI ). The higher values of coercivity (664–926 Oe) of these nanomaterials suggest their use in longitudinal recording media. - Graphical abstract: Nano-sized rare-earth (RE=La 3+ , Nd 3+ , Gd 3+ , Tb 3+ , Dy 3+ ) doped Ba 2 NiCoRE x Fe 28−x O 46 (x=0.25) hexagonal ferrites were synthesized for the first time via micro-emulsion route and the crystallite size was found in the range 7–19 nm. The enhancement in the coercivity was observed with the doping of rare-earth cations. The higher values of coercivity (664–926 Oe) of these nanomaterials suggest their use in longitudinal recording media. - Highlights: • Micro-emulsion route was used to synthesize Ba 2 NiCoRE x Fe 28−x O 46 ferrites. • The crystallite size was found in the range 7–19 nm. • The rare-earth incorporation enhanced the coercivity (664–926 Oe).

  15. DFT calculations, spectroscopic, thermal analysis and biological activity of Sm(III) and Tb(III) complexes with 2-aminobenzoic and 2-amino-5-chloro-benzoic acids

    Science.gov (United States)

    Essawy, Amr A.; Afifi, Manal A.; Moustafa, H.; El-Medani, S. M.

    2014-10-01

    The complexes of Sm(III) and Tb(III) with 2-aminobenzoic acid (anthranilic acid, AA) and 2-amino-5-chlorobenzoic acid (5-chloroanthranilic acid, AACl) were synthesized and characterized based on elemental analysis, IR and mass spectroscopy. The data are in accordance with 1:3 [Metal]:[Ligand] ratio. On the basis of the IR analysis, it was found that the metals were coordinated to bidentate anthranilic acid via the ionised oxygen of the carboxylate group and to the nitrogen of amino group. While in 5-chloroanthranilic acid, the metals were coordinated oxidatively to the bidentate carboxylate group without bonding to amino group; accordingly, a chlorine-affected coordination and reactivity-diversity was emphasized. Thermal analyses (TGA) and biological activity of the complexes were also investigated. Density Functional Theory (DFT) calculations at the B3LYP/6-311++G (d,p)_ level of theory have been carried out to investigate the equilibrium geometry of the ligand. The optimized geometry parameters of the complexes were evaluated using SDDALL basis set. Moreover, total energy, energy of HOMO and LUMO and Mullikan atomic charges were calculated. In addition, dipole moment and orientation have been performed and discussed.

  16. Magnetic ordering of Hf{sub 3}Ni{sub 2}Si{sub 3}-type {Sm, Tb, Er}{sub 3}Co{sub 2}Ge{sub 3} and {Tb, Ho}{sub 3}Ni{sub 2}Ge{sub 3} compounds

    Energy Technology Data Exchange (ETDEWEB)

    Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, Moscow, GSP-1, 119991 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation); Nirmala, R. [Indian Institute of Technology Madras, Chennai 600036 (India); Quezado, S.; Malik, S.K. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59082-970 (Brazil); Mozharivskyj, Y. [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1 (Canada); Isnard, O. [CNRS, Institut. Néel, 25 rue des Martyrs BP166 x, F-38042 Grenoble (France); Université Grenoble Alpes, Inst. Néel, F-38042 Grenoble (France)

    2017-02-15

    The magnetic ordering of Hf{sub 3}Ni{sub 2}Si{sub 3}-type {Sm, Tb, Er}{sub 3}Co{sub 2}Ge{sub 3} and {Tb, Ho}{sub 3}Ni{sub 2}Ge{sub 3} compounds (space group Cmcm, oC32) was investigated via magnetization measurements and neutron diffraction study in a zero-applied field. {Sm, Tb, Er}{sub 3}Co{sub 2}Ge{sub 3} and Ho{sub 3}Ni{sub 2}Ge{sub 3} exhibit field sensitive complex antiferromagnetic orderings with T{sub N}=51 K, T{sub m}=10 K for Sm{sub 3}Co{sub 2}Ge{sub 3}, T{sub N}=34 K, T{sub m}=13 K for Tb{sub 3}Co{sub 2}Ge{sub 3}, T{sub N}=7 K for Er{sub 3}Co{sub 2}Ge{sub 3} and T{sub N}=11 K for Ho{sub 3}Ni{sub 2}Ge{sub 3}. At 2 K and above the critical field of ~5 kOe, 20 kOe, 4 kOe and 7 kOe for Sm{sub 3}Co{sub 2}Ge{sub 3}, Tb{sub 3}Co{sub 2}Ge{sub 3}, Er{sub 3}Co{sub 2}Ge{sub 3} and Ho{sub 3}Ni{sub 2}Ge{sub 3}, respectively, saturation magnetizations per rare-earth atom are 6.5 μ{sub B} for Tb{sub 3}Co{sub 2}Ge{sub 3}, 7.0 μ{sub B} for Er{sub 3}Co{sub 2}Ge{sub 3} and 8.0 μ{sub B} for Ho{sub 3}Ni{sub 2}Ge{sub 3} in the field of 140 kOe, whereas magnetization of Sm{sub 3}Co{sub 2}Ge{sub 3} has an antiferromagnetic behaviour. The isothermal magnetic entropy change, ΔS{sub m}, indicates a field-induced ferromagnetic ordering in Sm{sub 3}Co{sub 2}Ge{sub 3}, Tb{sub 3}Co{sub 2}Ge3, Er{sub 3}Co{sub 2}Ge{sub 3} and Ho{sub 3}Ni{sub 2}Ge{sub 3} with a maximal ΔS{sub m} value of −10.9 J/kg K for Ho{sub 3}Ni{sub 2}Ge{sub 3} at 11 K for a field change of 50 kOe. In a zero-applied magnetic field, below T{sub N}=33 K and down to T{sub m}{sup ND}=15 K Tb{sub 3}Ni{sub 2}Ge{sub 3} shows an ac-antiferromagnetic ordering with the C2′/c magnetic space group, a K{sub 0}=[0, 0, 0] propagation vector and a a{sub Tb3Ni2Ge3}×b{sub Tb3Ni2Ge3}×c{sub Tb3Ni2Ge3} magnetic unit cell. Below T{sub m}{sup ND}=15 K, its magnetic structure is a sum of the ac-antiferromagnetic component with the C2′/c magnetic space group of the K{sub 0} vector and a sine-modulated a

  17. Kinetics of electrophilic exchange of lanthanide(3) and copper(2) ions in aqueous solutions of ethylenediaminetetraacetates. [Rare earths: La,Pr,Nd,Eu,Gd,Tb,Er,Yb

    Energy Technology Data Exchange (ETDEWEB)

    Nikitenko, S.I.; Martynenko, L.I.; Pechurova, N.I.; Spitsyn, V.I. (Moskovskij Gosudarstvennyj Univ. (USSR))

    1984-05-01

    Electrophilic exchange in the MA/sup -/ - Cu/sup 2 +/ (M/sup 3 +/=La/sup 3 +/, PUPSILON/sup 3 +/, Nd/sup 3 +/, Eu/sup 3 +/, Gd/sup 3 +/, Tb/sup 3 +/, Er/sup 3 +/, Yb/sup 3 +/, A/sup 4 -/=ethylenediaminetetraacetate) systems is studied. Copper is chosen as a constituent cation, because the stability of the CuA/sup 2 +/- complex is higher than that of the MA/sup -/ complex, besides the CuA/sup 2 -/, is characterized by a high extinction coefficient E/sub 280/=3200. Electrophilic exchange in the systems is shown to be realized through the acid dissociation mechanism and through the association mechanism. Consideration of the acid dissociation mechanism assumes that the exchange is limited by a break in the metal-oxygen bond in the intermediate protonated complex. In case of the association mechanism it is limited by a break in the metal-nitrogen bond in the intermediate binuclear complex. Rate constants of the limiting stage are calculated. Dependences of the rate constants of exchange on the stability of the complexes, the order number of the element, acidity of medium, Cu/sup 2 +/ concentration are given. Differences are shown to exist between the exchange mechanisms in the studied: systems for the REE of cerium and yttrium subgroups.

  18. 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.

  19. Study of hyperfine interactions in intermetallic compounds Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In; Estudo de interacoes hiperfinas em compostos intermetalicos Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In e Ho(Ni,Pd)In

    Energy Technology Data Exchange (ETDEWEB)

    Lapolli, Andre Luis

    2006-07-01

    Systematic behavior of magnetic hyperfine field (B{sub hf}) in the intermetallic compounds Gd(Ni,Pd,Cu)In Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In was studied by Perturbed Gamma-Gamma Angular Correlation spectroscopy. The measurements of B{sub hf} were carried out at the rare earth atom and in sites using the nuclear probes {sup 140}Ce and {sup 11}'1Cd respectively. The variation of hyperfine field with temperature, in most cases, follows the Brillouin function predicted from the molecular field theory. The hyperfine field values at rare earth atom sites obtained from {sup 140}Ce probe as well as at in sites obtained from {sup 111}Cd probe for each series of compounds were extrapolated to zero Kelvin B{sub hf}(T=0) from these curves. These values were compared with the values of the literature for other compounds containing the same rare earth element and all of them show a linear relationship with the ordering temperature. This indicates that the main contribution to B{sub hf} comes from the conduction electron polarization (CEP) through Fermi contact interaction and the principal mechanism of magnetic interaction in these compounds can be described by the RKKY type interaction. The values of B{sub hf}(T=0) for each family of intermetallic compounds RNiIn and RPdIn when plotted as a function of 4f spin projection of rare earth element also shows a linear relationship. Exceptions are the results for the compounds RNiIn obtained with {sup 111}Cd probe where a small deviation from linearity is observed. The results of the measurements carried out with the {sup 111}Cd probe were also analyzed to obtain the hyperfine parameters of the quadrupole interaction as a function of temperature for RPdln and GdNiIn compounds. The results show that for the compound GdPdIn there might be some Gd-In disorder at high temperature. (author)

  20. Study of hyperfine interactions in intermetallic compounds Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In; Estudo de interacoes hiperfinas em compostos intermetalicos Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In e Ho(Ni,Pd)In

    Energy Technology Data Exchange (ETDEWEB)

    Lapolli, Andre Luis

    2006-07-01

    Systematic behavior of magnetic hyperfine field (B{sub hf}) in the intermetallic compounds Gd(Ni,Pd,Cu)In Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In was studied by Perturbed Gamma-Gamma Angular Correlation spectroscopy. The measurements of B{sub hf} were carried out at the rare earth atom and in sites using the nuclear probes {sup 140}Ce and {sup 11}'1Cd respectively. The variation of hyperfine field with temperature, in most cases, follows the Brillouin function predicted from the molecular field theory. The hyperfine field values at rare earth atom sites obtained from {sup 140}Ce probe as well as at in sites obtained from {sup 111}Cd probe for each series of compounds were extrapolated to zero Kelvin B{sub hf}(T=0) from these curves. These values were compared with the values of the literature for other compounds containing the same rare earth element and all of them show a linear relationship with the ordering temperature. This indicates that the main contribution to B{sub hf} comes from the conduction electron polarization (CEP) through Fermi contact interaction and the principal mechanism of magnetic interaction in these compounds can be described by the RKKY type interaction. The values of B{sub hf}(T=0) for each family of intermetallic compounds RNiIn and RPdIn when plotted as a function of 4f spin projection of rare earth element also shows a linear relationship. Exceptions are the results for the compounds RNiIn obtained with {sup 111}Cd probe where a small deviation from linearity is observed. The results of the measurements carried out with the {sup 111}Cd probe were also analyzed to obtain the hyperfine parameters of the quadrupole interaction as a function of temperature for RPdln and GdNiIn compounds. The results show that for the compound GdPdIn there might be some Gd-In disorder at high temperature. (author)

  1. Hetero-metallic {3d-4f-5d} complexes: preparation and magnetic behavior of trinuclear [(L(Me2)Ni-Ln){W(CN)(8)}] compounds (Ln = Gd, Tb, Dy, Ho, Er, Y; L(Me2) = Schiff base) and variable SMM characteristics for the Tb derivative.

    Science.gov (United States)

    Sutter, Jean-Pascal; Dhers, Sébastien; Rajamani, Raghunathan; Ramasesha, S; Costes, Jean-Pierre; Duhayon, Carine; Vendier, Laure

    2009-07-06

    Assembling bimetallic {Ni-Ln}(3+) units and {W(CN)(8)}(3-) is shown to be an efficient route toward heteronuclear {3d-4f-5d} compounds. The reaction of either the binuclear [{L(Me2)Ni(H(2)O)(2)}{Ln(NO(3))(3)}] complexes or their mononuclear components [L(Me2)Ni] and Ln(NO(3))(3) with (HNBu(3))(3){W(CN)(8)} in dmf followed by diffusion of tetrahydrofuran yielded the trinuclear [{L(Me2)NiLn}{W(CN)(8)}] compounds 1 (Ln = Y), 2a,b (Gd), 3a,b (Tb), 4 (Dy), 5 (Ho), and 6 (Er) as crystalline materials. All of the derivatives possess the trinuclear core resulting from the linkage of the {W(CN)(8)} to the Ni center of the {Ni-Ln} unit. Differences are found in the solvent molecules acting as ligands and/or in the lattice depending on the crystallization conditions. For all the compounds ferromagnetic {Ni-W} and {Ni-Ln} (Ln = Gd, Tb, Dy, and Er} interactions are operative resulting in high spin ground states. Parameterization of the magnetic behaviors for the Y and Gd derivatives confirmed the strong cyano-mediated {Ni-W} interaction (J(NiW) = 27.1 and 28.5 cm(-1)) compared to the {Ni-Gd} interaction (J(NiGd) = 2.17 cm(-1)). The characteristic features for slow relaxation of the magnetization are observed for two Tb derivatives, but these are modulated by the crystal phase. Analysis of the frequency dependence of the alternating current susceptibility data yielded U(eff)/k(B) = 15.3 K and tau(0) = 4.5 x 10(-7) s for one derivative whereas no maxima of chi(M)'' appear above 2 K for the second one.

  2. β-Y(BO{sub 2}){sub 3}. A new member of the β-Ln(BO{sub 2}){sub 3} (Ln = Nd, Sm, Gd-Lu) structure family

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Martin K.; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2017-07-01

    β-Y(BO{sub 2}){sub 3} was synthesized in a Walker-type multianvil module at 5.9 GPa/1000 C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO{sub 2}){sub 3} crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a = 15.886(2), b = 7.3860(6), and c = 12.2119(9) Aa. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO{sub 2}){sub 3} (Ln = Nd, Sm, Gd-Lu).

  3. 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.

  4. 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.

  5. Magnetization fluctuation analysis and superconducting parameters of La0.5RE0.5BaCaCu3O7-δ(RE=Y, Sm, Gd, Dy, Ho, Yb) superconductor

    International Nuclear Information System (INIS)

    Parra Vargas, C.A.; Pimentel, J.L.; Pureur, P.; Landinez Tellez, D.A.; Roa-Rojas, J.

    2009-01-01

    In this work we report the analysis of magnetization experimental data of the La 0.5 RE 0.5 BaCaCu 3 O 7-δ (RE=Y, Sm, Gd, Dy, Ho, Yb) superconducting system. The data are analyzed in terms of thermal fluctuations on the magnetization excess ΔM(T) for different values of temperature in each one of the samples. We describe a procedure for extracting the penetration depth λ ab (∼1571A) and the coherence length ξ ab (∼1.52A) parameters from the magnetization, as a function of the applied magnetic field. This procedure was performed for polycrystalline samples of La 0.5 RE 0.5 BaCaCu 3 O 7-δ by using the theory of Bulaevskii, Ledvij and Kogan, which analyzes the vortex fluctuation in superconducting materials within the Lawrence-Doniach framework. These data allowed to determine the characteristic temperature value T * (73, 58, 48, 57, 56, 71 K, for RE=Y, Sm, Gd, Dy, Ho, Yb, respectively) in the magnetization curves for several magnetic fields. We calculated the data of magnetization excess from the curves of magnetization as a function of logarithm of applied field. We notice that the values for these superconducting parameters are in agreement with the reports for high temperature superconductors. The obtained value of superconducting volumetric fraction is compared with that obtained through the measure of the Meissner effect.

  6. Formation of modified TbCu{sub 7} and Th{sub 2}Zn{sub 17} type structures during annealing of mechanical-alloyed Sm-Fe powders

    Energy Technology Data Exchange (ETDEWEB)

    Teresiak, A.; Kubis, M.; Mattern, N.; Wolf, M.; Mueller, K.-H. [Inst. fuer Festkoerper- und Werkstofforschung, Dresden (Germany)

    1998-06-26

    Compounds with the nominal composition near Sm{sub 2}Fe{sub 17} were prepared by mechanical alloying starting from the elemental powders and subsequent annealing at temperatures, T{sub A}, between 600 C and 900 C. For crystal structure investigations of the non-equilibrium phases formed at various temperatures, XRD methods with following Rietveld analysis were applied. For T{sub A} between 600 C and 750 C a modified TbCu{sub 7}-type structure of space group P6/mmm was found, in which the Fe(2c) site is replaced by the partially (1/3) and randomly occupied Fe(6l) site. Its approximate composition is SmFe{sub 8.8-9.0}. For T{sub A} between 800 C to 900 C a disordered modified Th{sub 2}Zn{sub 17} structure (space group R anti 3m) was found that is formed by introducing additional randomly occupied Fe (6c) and Sm(3a) positions, respectively. The degree of order of Sm atoms and Fe-dumbbells along the c-direction increases with increasing T{sub A}. A decrease in the Fe concentration in the cell is observed for increasing T{sub A}. The completely ordered stoichiometric Th{sub 2}Zn{sub 17}-type structure could not be reached by annealing samples prepared from the ball-milled elemental powders. (orig.) 20 refs.

  7. 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

  8. Re-dispersion and film formation of GdVO4 :  Ln3+ (Ln3+ = Dy3+, Eu3+, Sm3+, Tm3+) nanoparticles: particle size and luminescence studies.

    Science.gov (United States)

    Shanta Singh, N; Ningthoujam, R S; Phaomei, Ganngam; Singh, S Dorendrajit; Vinu, A; Vatsa, R K

    2012-04-21

    GdVO(4) : Ln(3+) (Ln(3+) = Dy(3+), Eu(3+), Sm(3+), Tm(3+)) nanoparticles are prepared by a simple chemical route at 140 °C. The crystallite size can be tuned by varying the pH of the reaction medium. Interestingly, the crystallite size is found to increase significantly when pH increases from 6 to 12. This is related to slower nucleation of the GdVO(4) formation with increase of VO(4)(3-) present in solution. The luminescence study shows an efficient energy transfer from vanadate absorption of GdVO(4) to Ln(3+) and thereby enhanced emissions are obtained. A possible reaction mechanism at different pH values is suggested in this study. As-prepared samples are well dispersed in ethanol, methanol and water, and can be incorporated into polymer films. Luminescence and its decay lifetime studies confirm the decrease in non-radiative transition probability with the increase of heat treatment temperature. Re-dispersed particles will be useful in potential applications of life science and the film will be useful in display devices.

  9. A study of luminescence from Eu{sup 3+}, Ce{sup 3+}, Tb{sup 3+} and Ce{sup 3+}/Tb{sup 3+} in new potassium gadolinium phosphate K{sub 3}Gd{sub 5}(PO{sub 4}){sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Fangui; Zhang, Hongzhi [School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004 (China); Chen, Cuili; Kim, Sun Il [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Zhang, Xinmin, E-mail: xmzhuga@163.com [School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004 (China)

    2016-06-25

    New potassium gadolinium phosphate [K{sub 3}Gd{sub 5}(PO{sub 4}){sub 6}] doped with Eu{sup 3+}, Ce{sup 3+}, Tb{sup 3+} and co-doped with Ce{sup 3+} and Tb{sup 3+} phosphors were prepared by high temperature solid state synthesis. Phase purity of the powders was checked by X-ray powder diffraction. Luminescence and excitation spectra of samples were reported. In particular, the interaction mechanism between Eu{sup 3+} ions was investigated in terms of the Inokuti–Hirayama model; it was found that the interactions between Eu{sup 3+} can be assigned to dipole–dipole interaction. K{sub 3}Gd{sub 5}(PO{sub 4}){sub 6}:Eu{sup 3+} could act as a candidate for solid state lighting due to its strong absorption band in the near-UV region (350–400 nm). The energy transfer from Ce{sup 3+} to Tb{sup 3+} was confirmed and the mechanism was studied using Dexter's theory; it is concluded that electric dipole–dipole interaction predominates in the energy transfer process from Ce{sup 3+} to Tb{sup 3+} in the K{sub 3}Gd{sub 5}(PO{sub 4}){sub 6} host. The energy transfer efficiency and critical distance were also investigated. - Highlights: • Optical properties of K{sub 3}Gd{sub 5}(PO{sub 4}){sub 6}:RE{sup 3+} are investigated for the first time. • The interaction mechanism between Eu{sup 3+} ions is attributed to dipole–dipole type. • K{sub 3}Eu{sub 5}(PO{sub 4}){sub 6} is a candidate phosphor for application to solid state lighting. • There exists an efficient energy transfer from Ce{sup 3+} to Tb{sup 3+} (η is up to 95%). • The mechanism of energy transfer process is electric dipole–dipole interaction.

  10. The Gd-Co-Al system at 870/1070 K as a representative of the rare earth-Co-Al family and new rare-earth cobalt aluminides: Crystal structure and magnetic properties

    Science.gov (United States)

    Morozkin, A. V.; Garshev, A. V.; Knotko, A. V.; Yapaskurt, V. O.; Mozharivskyj, Y.; Yuan, Fang; Yao, Jinlei; Nirmala, R.; Quezado, S.; Malik, S. K.

    2018-05-01

    The Gd-Co-Al system has been investigated at 870/1070 K by X-ray and elemental EDS analyses. The existence of the known compounds Gd2Co3Al9 (Y2Co3Ga9-type), Gd3Co4.5Al11.5 (Gd3Co4.6Al11) (Gd3Ru4Al12-type), Gd3Co6-7.4Al3-1.6 (CeNi3-type), GdCo1.15-0.65Al0.85-1.35 (MgZn2-type), Gd2Co2Al (Mo2NiB2-type) and Gd3Co3.5-3.25Al0.5-0.75 (W3CoB3-type) has been confirmed at 870/1070 K. Structure types have been determined for Gd2Co6Al19 (U2Co6Al19-type), Gd7Co6Al7 (Pr7Co6Al7-type), Gd6Co2-2.21Al1-0.79 (Ho6Co2Ga-type) and Gd14Co3.2Al2.8 (Gd14Co2.58Al3.42 at 970 K) (Lu14Co3In3-type). The structures of Gd6Co2Al, Gd6Co2.21Al0.79 and Gd14Co2.58Al3.42 flux-grown at 970 K have been refined from the single crystal X-ray diffraction data. Additionally, new ternary compounds Gd2Co5.7-5.3Al1.3-1.7 (Er2Co7-type) and Gd58Co20Al22 (unknown type structure) have been identified. Quasi-binary solid solutions were detected for Gd2Co17, GdCo5, Gd2Co7, GdCo3, GdCo2 and GdAl2 at 870/1070 K, while no appreciable solubility was observed for the other binary compounds in the Gd-Co-Al system. Magnetic properties of the Gd2Co3Al9, Gd3Co4.6Al11, Gd7Co6Al7, Gd6Co2.2Al0.8 and Gd14Co2.58Al3.42 compounds have been studied and are presented in this work. Gd6Co2.2Al0.8, Gd3Co4.6Al11, Gd7Co6Al7 and Gd14Co2.58Al3.42 order ferromagnetically, while Gd2Co3Al9 displays antiferromagnetic transition. Additionally, {Y, Sm, Tb - Tm}2Co6Al19 (U2Co6Al19-type), Yb2Co3Al9 (Y2Co3Ga9-type), {Y, Sm, Tm, Yb}3Co4.6Al11 (Gd3Ru4Al12-type) and Tb7Co6Al7 (Pr7Co6Al7-type) compounds have been synthesized and investigated.

  11. Use of the ion exchange method for the determination of stability constants of trivalent metal complexes with humic and fulvic acids II. Tb3+, Yb3+ and Gd3+ complexes in weakly alkaline conditions

    International Nuclear Information System (INIS)

    Dong Wenming; Li Weijuan; Tao Zuyi

    2002-01-01

    The conditional stability constants for tracer concentrations of Tb(III), Yb(III), and Gd(III) with three soil humic acids, three soil fulvic acids and a fulvic acid from weathered coal were determined at pH 9.0-9.1 (these values are similar to those in calcareous soils) in the presence of NaHCO 3 by using the anion exchange method. It was found that 1 : 1 and 1 : 2 complexes were simultaneously formed in the weakly alkaline conditions. The conditional stability constants of these 1 : 1 and 1 : 2 complexes were calculated from the distribution coefficients of rare earth elements at various concentrations of humate or fulvate. The stability constants indicate the very high stability of trivalent Tb 3+ , Yb 3+ and Gd 3+ complexes with humic substances in weakly alkaline conditions. The key parameters necessary for the experimental determination of the conditional stability constants of metal ions with humic substances in the presence of NaHCO 3 by using an anion exchange method were discussed. The conditional stability constants of these 1 : 1 and 1 : 2 complexes were compared in this paper. It was found that stabilities of Tb 3+ 1 : 1 and 1 : 2 complexes with humic acid are greater than the corresponding ones with fulvic acid from the same soil. In addition, the effect of the presence of Ca 2+ as a competitor on the stabilities of 1 : 1 and 1 : 2 complexes of Yb was examined and no pronounced change of stabilities of 1 : 1 complex was found, even though Ca 2+ is in a 10 3 excess to Yb 3+

  12. Oxide fluoride sulfides of the lanthanoids with the formula M{sub 6}O{sub 2}F{sub 8}S{sub 3} (M = La-Nd, Sm, Gd); Oxidfluoridsulfide der Lanthanoide vom Formeltyp M{sub 6}O{sub 2}F{sub 8}S{sub 3} (M = La-Nd, Sm, Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Grossholz, Hagen; Zimmermann, Dirk D.; Janka, Oliver; Schleid, Thomas [Stuttgart Univ. (Germany). Inst. fuer Anorganische Chemie

    2013-07-15

    The lanthanoid(III) oxide fluoride sulfides M{sub 6}O{sub 2}F{sub 8}S{sub 3} (M = La-Nd, Sm, Gd) can be obtained by reacting the rare-earth metals, their trifluorides and sesquioxides with elemental sulfur in appropriate molar ratios at 850 C flux-assisted by NaCl in gas-tightly sealed niobium or tantalum ampoules. All compounds are colorless, except for those containing M = Pr with green, M = Nd with lilac and M = Sm with yellow color. They form transparent single crystals as needles or rods. The M{sub 6}O{sub 2}F{sub 8}S{sub 3} representatives crystallize in a hexagonal structure (space group: P6{sub 3}/m; a {approx} 1382-1326, c {approx} 398-376 pm, c/a {approx} 0.288-0.284; Z = 2) with two different crystallographic M{sup 3+} positions. The (M2){sup 3+} cations reside in ninefold coordination of anions arranged as tricapped trigonal prisms formed by three F{sup -}, four mixed-occupied O{sup 2-}/F{sup -} and two S{sup 2-} anions, resembling the unique M{sup 3+} coordination sphere of the M{sub 3}OF{sub 5}S-type oxide fluoride sulfides. The (M1){sup 3+} cations are surrounded by square antiprisms built of four O{sup 2-}/F{sup -} and S{sup 2-} anions each, which are capped by one F{sup -} anion each, again resulting in a ninefold coordination similar to that of the A-MFS-type fluoride sulfides. While the crystallographically unique S{sup 2-} anions have six cationic neighbors arranged in trigonal prisms, there are four different light-anion positions. Two of them, representing only fluoride anions, are situated in a triangular environment of cations ((F1){sup -}: planar, (F2){sup -}: non-planar). The mixed-occupied light-anion positions (F3){sup -}/(O3){sup 2-} and (F4){sup -}/(O4){sup 2-} exhibit tetrahedral coordination spheres with a ratio F{sup -}: O{sup 2-} = 2:1. The M{sub 6}O{sub 2}F{sub 8}S{sub 3} arrangement is characterized by an empty hexagonal channel structure created by (F1){sup -} anions with a potential of accommodating alkali-metal cations like Na

  13. 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.

  14. Estimation of tau1 for the host Kramers' Ln3+ ions (Ln = Nd, Sm and Yb) from the EPR linewidths of Gd3+ impurity ions in Ln2(SO4)3.8H2O

    International Nuclear Information System (INIS)

    Malhotra, V.M.; Buckmaster, H.A.

    1981-01-01

    It is shown that the EPR linewidth data published by Misra and Mikolajczak for Gd 3+ impurity ions in Ln 2 (SO 4 ) 3 .8H 2 O (Ln = Nd, Sm and Yb) single crystals at 77 and 300 K can be used to estimate the effective spin-lattice relaxation time of Kramers' host ions. The various relaxation mechanisms which are operative in the lanthanides are reviewed and discussed. The estimated relaxation times are shown to be a sensitive function of the host ion energy level splittings and the temperature. The estimated effective spin-lattice relaxation times in these hosts are in reasonable agreement with those expected from a resonance Orbach process

  15. K2Ln2As2Se9 (Ln = Sm, Gd): the first quaternary rare-earth selenoarsenate compounds with a 3D framework containing chairlike As2Se4 units.

    Science.gov (United States)

    Wu, Yuandong; Bensch, Wolfgang

    2009-04-06

    The new compounds K(2)Ln(2)As(2)Se(9) (Ln = Sm, Gd) were obtained by applying the reactive flux method. The structure consists of a three-dimensional (3D) [Ln(2)As(2)Se(9)](2-) framework with K(+) ion-filling tunnels running along the b axis. The two unique Ln(3+) cations are coordinated by two Se(2)(2-) dumbbells, two AsSe(3)(3-) pyramids, and one chairlike As(2)Se(4)(2-) unit in a bicapped trigonal-prismatic geometry. The Ln(3+)-centered trigonal prisms share triangular faces with neighboring prisms, forming one-dimensional chains along the b axis. These chains are linked to each other to form layers by sharing Se(2-) anions on the capped sites of the trigonal prisms. The As(2)Se(4) units connect these layers to form the 3D framework.

  16. Stabilization of the ferromagnetic metallic state in rare earth-doped La0.49X0.01Ca0.50MnO3+δ (X=Nd, Sm, Gd and Yb)

    International Nuclear Information System (INIS)

    Aslam, Affia; Hasanain, S.K.; Akhtar, M.J.; Nadeem, M.

    2006-01-01

    We report the effects of disorder induced by a small amount of substitution of the smaller cations (Nd, Sm, Gd and Yb) for La in the La 0.50 Ca 0.50 MnO 3+δ system. With decreasing size of the dopant, the ferromagnetic and metallic state is stabilized while the AFM and insulating behaviour is completely eliminating. The magnetic moment below T c increases in general, with decreasing dopant size. The behaviour is interpreted in terms of the destabilization of the charge ordering (CO) due to the disorder induced by the size mismatch of the cations. Our data support the view that close to the COI-FM phase boundary, the effect of disorder is to weaken the CO that is more sensitive to disorder, whereas it leaves the more robust double exchange relatively unaffected, thereby extending the region in phase space where the FM phase is stable

  17. 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.)

  18. 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.

  19. 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)

  20. Study of hyperfine interactions in intermetallic compounds Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In

    International Nuclear Information System (INIS)

    Lapolli, Andre Luis

    2006-01-01

    Systematic behavior of magnetic hyperfine field (B hf ) in the intermetallic compounds Gd(Ni,Pd,Cu)In Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In was studied by Perturbed Gamma-Gamma Angular Correlation spectroscopy. The measurements of B hf were carried out at the rare earth atom and in sites using the nuclear probes 140 Ce and 11 '1Cd respectively. The variation of hyperfine field with temperature, in most cases, follows the Brillouin function predicted from the molecular field theory. The hyperfine field values at rare earth atom sites obtained from 140 Ce probe as well as at in sites obtained from 111 Cd probe for each series of compounds were extrapolated to zero Kelvin B hf (T=0) from these curves. These values were compared with the values of the literature for other compounds containing the same rare earth element and all of them show a linear relationship with the ordering temperature. This indicates that the main contribution to B hf comes from the conduction electron polarization (CEP) through Fermi contact interaction and the principal mechanism of magnetic interaction in these compounds can be described by the RKKY type interaction. The values of B hf (T=0) for each family of intermetallic compounds RNiIn and RPdIn when plotted as a function of 4f spin projection of rare earth element also shows a linear relationship. Exceptions are the results for the compounds RNiIn obtained with 111 Cd probe where a small deviation from linearity is observed. The results of the measurements carried out with the 111 Cd probe were also analyzed to obtain the hyperfine parameters of the quadrupole interaction as a function of temperature for RPdln and GdNiIn compounds. The results show that for the compound GdPdIn there might be some Gd-In disorder at high temperature. (author)

  1. 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.

  2. Rare Earth Chalcogels NaLnSnS4 (Ln = Y, Gd, Tb) for Selective Adsorption of Volatile Hydrocarbons and Gases

    KAUST Repository

    Edhaim, Fatimah; Rothenberger, Alexander

    2017-01-01

    that the new materials have pores in the macro (above 50 nm) and meso (2–50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO2 over CH4 or H2. The notable adsorption capacity for toluene (NaYSnS4: 1108 mg·g–1; NaGdSn

  3. 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.

  4. 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)

  5. Heat capacity of RFe{sub x}Mn{sub 12-x} (R = Gd, Tb and Dy) compounds: wiping out a cooperative 4f-4f exchange interaction by breaking the 3d-4f magnetic symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Pique, C; Blanco, J A; Abad, E [Departamento de Fisica, Universidad de Oviedo, Campus de Viesques, E-33204 Gijon (Spain); Burriel, R; Artigas, M [Instituto de Ciencia de Materiales de Aragon (CSIC-Universidad de Zaragoza), E-50009 Zaragoza (Spain); Fernandez-RodrIguez, J [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex (France)], E-mail: pique@uniovi.es

    2008-08-27

    Using adiabatic calorimetry the heat capacity of a series of RFe{sub x}Mn{sub 12-x} (R = Gd, Tb and Dy) compounds has been measured from 3 to 350 K. The substitution of Fe for Mn in RFe{sub x}Mn{sub 12-x} influences both the magnetic interactions on the 3d sublattice and the magnetism of R (the Neel temperature doubles on going from x = 0 to 6 and the compounds become ferromagnetic for x = 8 with Curie temperatures of around 300 K). In pure TbMn{sub 12} the heat-capacity data shows a {lambda}-type anomaly associated with the independent cooperative magnetic ordering of the R sublattice ({approx}5 K), while the anomaly related to the Mn magnetic ordering ({approx}100 K) is rather smooth, as observed in other itinerant magnetic systems such as YMn{sub 12}. In contrast, the substitution of Fe for Mn leads, on the one hand, to a more localized magnetic behaviour of the 3d sublattice, and, on the other, to magnetic polarization effects between the 3d and 4f sublattices, together with the disappearance of the cooperative magnetic ordering of the R sublattice due to the breaking of the antiferromagnetic symmetry in the 3d sublattice. This is reflected in the heat-capacity curve through a smooth Schottky-like anomaly. In the case of Gd compounds the magnitude of the exchange molecular-field parameter has been deduced by fitting the magnetic contribution to the heat capacity within a simple mean-field model. From this analysis we found that this molecular field acting on the rare-earth site increases with the iron concentration, reaching values as large as 48 T for the concentration x = 6. A similar analysis of the heat capacity in the ordered phase on the Tb compounds also leads to an enhancement of the molecular field with increasing Fe content. These results allow checking the possible crystal-field parameters for these RFe{sub x}Mn{sub 12-x} compounds.

  6. 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.

  7. 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

    International Nuclear Information System (INIS)

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

    2017-01-01

    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 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 2 in N 2 atmosphere. The results of SAXS, XRD, N 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 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.

  8. 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....

  9. Completing the series. New coordination networks of composition {sup 3}{sub ∞}[RE{sub 2}(ADC){sub 3}(H{sub 2}O){sub 6}].2H{sub 2}O with RE = Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Y and ADC{sup 2-} = acetylenedicarboxylate ({sup -}O{sub 2}C-C≡C-CO{sub 2}{sup -})

    Energy Technology Data Exchange (ETDEWEB)

    Gramm, Verena K.; Schuy, Andrea; Ruschewitz, Uwe [Institut fuer Anorganische Chemie, Koeln Univ. (Germany); Suta, Markus; Wickleder, Claudia [Anorganische Chemie, Universitaet Siegen (Germany); Sternemann, Christian [Fakultaet Physik / DELTA, Technische Universitaet Dortmund (Germany)

    2018-02-01

    The crystal structures of {sup 3}{sub ∞}[RE{sub 2}(ADC){sub 3}(H{sub 2}O){sub 6}].2H{sub 2}O (RE = Pr, Nd, Sm, Eu, Tb, Dy) were solved and refined from X-ray single crystal data. They crystallize in a structure type already known for RE = La, Ce and Gd (P1, no. 2, Z = 2), which is characterized by REO{sub 9} polyhedra forming dimeric units being the nodes of a 3D framework structure linked by ADC{sup 2-} anions ({sup -}O{sub 2}C-C≡C-CO{sub 2}{sup -} = acetylenedicarboxylate). From synchrotron powder diffraction data it was shown that isostructural coordination networks are formed for RE = Ho, Er, Y, whereas for RE = Tm, Yb, Lu a new structure type crystallizing in a highly complex crystal structure with a large orthorhombic unit cell is found. All compounds are obtained by slow evaporation of an aqueous solution containing RE(OAc){sub 3}.xH{sub 2}O and acetylenedicarboxylic acid (H{sub 2}ADC). The coordination networks of composition {sup 3}{sub ∞}[RE{sub 2}(ADC){sub 3}(H{sub 2}O){sub 6}].2H{sub 2}O were thoroughly investigated by thermal analysis and for RE = Eu, Tb, a strong red and green photoluminescence was observed and investigated by means of UV/Vis spectroscopy. (copyright 2018 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Proton configurations and pairing correlations at the N=80 superdeformed shell closure: Study of 145Tb

    International Nuclear Information System (INIS)

    Mullins, S.M.; Schmeing, N.C.; Flibotte, S.; Hackman, G.; Rodriguez, J.L.; Waddington, J.C.; Yao, L.; Andrews, H.R.; Galindo-Uribarri, A.; Janzen, V.P.; Radford, D.C.; Ward, D.; DeGraaf, J.; Drake, T.E.; Pilotte, S.; Paul, E.S.

    1994-01-01

    A superdeformed band has been observed in the N=80 nucleus 145 Tb which was produced with the reactions 112 Sn( 37 Cl,2p2n) and 118 Sn( 31 P,4n) at bombarding energies of 187 and 160 MeV, respectively. Since superdeformed bands also exist in the three lighter N=80 isotones 142 Sm, 143 Eu, and 144 Gd, it is now possible to understand the valence-proton configurations of these bands in a systematic way. The T (2) dynamic moment of inertia in 145 Tb shows no evidence for the N = 6 quasiproton crossing that is observed in 144 Gd. Comparison with cranked Woods-Saxon and total Routhian surface calculations suggests that the proton configuration in 145 Tb is 6 1 direct-product[404] 9/2 + 2 in which the quasiproton crossing is blocked. Furthermore, like 143 Eu and 142 Sm, there is no evidence in the T (2) for the N=6 quasineutron crossing predicted by the calculations. This may indicate that static neutron pairing correlations are quenched at the N=80 superdeformed shell closure

  11. RE{sub 3}Ga{sub 9}Ge (RE=Y, Ce, Sm, Gd and Yb): compounds with an open three-dimensional polygallide framework synthesized from liquid gallium

    Energy Technology Data Exchange (ETDEWEB)

    Zhuravleva, M A; Kanatzidis, M G

    2003-07-01

    The RE{sub 3}Ga{sub 9}Ge compounds (RE=Y, Ce, Sm, Gd and Yb) were synthesized at 850 deg. C in quantitative yield from reactions containing excess liquid Ga. The orthorhombic crystal structure is characterized by a unique three-dimensional open Ga framework with parallel straight tunnels. In the tunnels, inserted are arrays of the RE atoms together with interpenetrated monoatomic RE-Ga-Ge planes. A complex disordered arrangement of the RE and Ga atoms is observed in the monoatomic plane. Depending on the extent of disorder, the crystal structure could be presented either in a sub-cell (no ordering) or in a super-cell (partial ordering). Single-crystal X-ray data for Ce{sub 3}Ga{sub 9}Ge sub-structure: space group Immm, Z=2, cell parameters a=4.3400(12) A; b=10.836(3) A; and c=11.545(3) A; super-structure: space group Cmma, Z=8, cell parameters a=8.680(3) A; b=23.090(7) A; and c=10.836(3) A. The refinement based on the full-matrix least squares on F{sub o}{sup 2}[I>2{sigma}(I)] converged to final residuals R{sub 1}/wR{sub 2}=0.0226/0.0528 and 0.0729/0.1569 for the sub- and super-structures, respectively. The relationship between the disordered sub-structure and partially ordered super-structure is discussed. Magnetic susceptibility measurements show Curie-Weiss behavior at the temperatures above 30 K with the negative Weiss constants {theta}=-49(1) and-7.7 K for Gd and Ce analogs, respectively. An antiferromagnetic transition is observed in the Gd analog at T{sub N}=26.1 K. The {mu}{sub eff} obtained for both analogs is close to the RE{sup 3+} free-ion value.

  12. 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

  13. 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.

  14. 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

  15. Effects of annealing on the microstructure, corrosion resistance, and mechanical properties of RE{sub 65}Co{sub 25}Al{sub 10} (RE=Ce, La, Pr, Sm, and Gd) bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Zhou [School of Materials Science and Engineering, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China); Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China); Xing, Qi; Sun, Zhenxi; Xu, Jing; Zhao, Zhengfeng [School of Materials Science and Engineering, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China); Chen, Shuying; Liaw, Peter K. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN (United States); Wang, Yan, E-mail: mse_wangy@ujn.edu.cn [School of Materials Science and Engineering, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China); Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China)

    2015-02-25

    The effects of annealing on the microstructure, corrosion resistance and mechanical properties of the RE{sub 65}Co{sub 25}Al{sub 10} (RE=Ce, La, Pr, Sm, and Gd) bulk metallic glasses (BMGs) were studied. Microstructural changes are induced after annealing below the onset crystallization temperature of 484 K, resulting in the variation of thermal stability and crystallization behavior. A proper annealing enhances the corrosion resistance in 3.5 wt% NaCl solution, which can be attributed to reduction of the electrochemical activity and galvanic coupling effects in the chloride solution. Moreover, the RE-based BMG annealed at 484 K possesses the higher corrosion potential and lower corrosion current density, combined with the corrosion morphologies, which suggests the best corrosion resistance. Annealing can also obviously change the mechanical properties and fracture morphologies. It presents that free volume annihilation can cause more difficulty in the elastic atom rearrangement for the as-annealed RE-based BMGs.

  16. 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

  17. Energies, Wavelengths, and Transition Rates for Ga-Like Ions (Nd XXX-Tb XXXV)

    Science.gov (United States)

    El-Sayed, Fatma; Attia, S. M.

    2016-03-01

    Energies, wavelengths, transition probabilities, oscillator strengths, and line strengths have been calculated for 4s24p-4s4p2 and 4s24p-4s24d transitions in gallium-like ions from Z = 60 to 65, for Nd XXX, Pm XXXI, Sm XXXII, Eu XXXIII, Gd XXXIV, and Tb XXXV using the fully relativistic multiconfi guration Dirac-Fock method. The correlation with the n = 4 complex and the quantum electrodynamic effects have been considered in the calculations. The obtained results have been compared with the available experimental and other theoretical results.

  18. The new carbodiimide Li_2Gd_2Sr(CN_2)_5 having a crystal structure related to that of Gd_2(CN_2)_3

    International Nuclear Information System (INIS)

    Unverfehrt, Leonid; Stroebele, Markus; Meyer, H. Juergen

    2013-01-01

    The new carbodiimide compounds Li_2RE_2Sr(CN_2)_5 (RE = Sm, Gd, Eu, Tb) were prepared by a straight forward solid state metathesis reaction of REF_3, SrF_2, and Li_2(CN_2) at around 600 C. The crystal structure of Li_2Gd_2Sr(CN_2)_5 was solved based on X-ray single-crystal diffraction data. Corresponding Li_2RE_2Sr(CN_2)_5 compounds were analyzed by isotypic indexing of their powder patterns. The crystal structure of Li_2Gd_2Sr(CN_2)_5 can be well related to that of Gd_2(CN_2)_3, because both structures are based on layered structures composed of close packed layers of [N=C=N]"2"- sticks, alternating with layers of metal ions. The crystal structure of Li_2Gd_2Sr(CN_2)_5 can be considered to contain an ABC layer sequence of [N = C=N]"2"- layers with the interlayer voids being occupied by (three) distinct types of cations. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Evaluation of optoelectronic response and Raman active modes in Tb{sup 3+} and Eu{sup 3+}-doped gadolinium oxide (Gd{sub 2}O{sub 3}) nanoparticle systems

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Nibedita [National Institute of Technology Nagaland, Department of Physics, Dimapur, Nagaland (India); Tezpur University, Department of Physics, Tezpur, Assam (India); Mohanta, D. [Tezpur University, Department of Physics, Tezpur, Assam (India)

    2016-09-15

    Rare earth oxide (Tb{sup 3+}:Gd{sub 2}O{sub 3} and Eu{sup 3+}:Gd{sub 2}O{sub 3}) nanophosphors are exploited through spectroscopic and microscopic tools with special emphasis on D-F mediated radiative emission and Raman active vibrational modes. Powder X-ray diffraction measurements have revealed cubic crystal structure of the nanosystems and with an average crystallite size varying between ∝3.2 and 4.8 nm. Photoluminescence (PL) spectra of Tb{sup 3+} doped systems signify intense blue-green (∝490 nm) and green (∝544 nm) emissions mediated by {sup 5}D{sub 4} → {sup 7}F{sub 6} and {sup 5}D{sub 4} → {sup 7}F{sub 5} transitional events; respectively. In the PL responses of Eu{sup 3+} doped nanoparticle systems, we also identify magnetically-driven {sup 5}D{sub 0} → {sup 7}F{sub 1} (∝591 nm) and electrically driven {sup 5}D{sub 0} → {sup 7}F{sub 2} (∝619 nm) radiative features which seem to improve with increasing doping level. However, the magnitude of Judd-Ofelt (J-O) intensity parameters (Ω {sub 2,} {sub 4}), is significantly lowered for the high doping cases. Raman spectra of the undoped and RE doped systems exhibited several A{sub g} and F{sub g} modes in the range of Raman shift ∝100-600 cm{sup -1}. In the Raman spectra, the peaks located at ∝355 cm{sup -1} are assigned to the mixed mode of F{sub g} + A{sub g}, the line width of which was found to increase with RE doping. Moreover, owing to the enhanced defect concentration in the doped systems than its undoped counterpart, we anticipate a faster phonon relaxation and consequently, a suppression of phonon lifetime in the former case. (orig.)

  20. TB Terms

    Science.gov (United States)

    ... sputum can also be used to do a culture. TB blood test – a test that uses a blood sample to find out if you are infected with TB bacteria. The test measures the response to TB proteins when they are mixed with a small amount of blood. Examples of these TB blood tests include QuantiFERON ® -TB ...

  1. Emission analysis of Tb3+ -and Sm3+ -ion-doped (Li2 O/Na2 O/K2 O) and (Li2 O + Na2 O/Li2 O + K2 O/K2 O + Na2 O)-modified borosilicate glasses.

    Science.gov (United States)

    Naveen Kumar Reddy, B; Sailaja, S; Thyagarajan, K; Jho, Young Dahl; Sudhakar Reddy, B

    2018-05-01

    Four series of borosilicate glasses modified by alkali oxides and doped with Tb 3+ and Sm 3+ ions were prepared using the conventional melt quenching technique, with the chemical composition 74.5B 2 O 3 + 10SiO 2 + 5MgO + R + 0.5(Tb 2 O 3 /Sm 2 O 3 ) [where R = 10(Li 2 O /Na 2 O/K 2 O) for series A and C, and R = 5(Li 2 O + Na 2 O/Li 2 O + K 2 O/K 2 O + Na 2 O) for series B and D]. The X-ray diffraction (XRD) patterns of all the prepared glasses indicate their amorphous nature. The spectroscopic properties of the prepared glasses were studied by optical absorption analysis, photoluminescence excitation (PLE) and photoluminescence (PL) analysis. A green emission corresponding to the 5 D 4 → 7 F 5 (543 nm) transition of the Tb 3+ ions was registered under excitation at 379 nm for series A and B glasses. The emission spectra of the Sm 3+ ions with the series C and D glasses showed strong reddish-orange emission at 600 nm ( 4 G 5/2 → 6 H 7/2 ) with an excitation wavelength λ exci = 404 nm ( 6 H 5/2 → 4 F 7/2 ). Furthermore, the change in the luminescence intensity with the addition of an alkali oxide and combinations of these alkali oxides to borosilicate glasses doped with Tb 3+ and Sm 3+ ions was studied to optimize the potential alkali-oxide-modified borosilicate glass. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Solid-state amorphization of SmFe{sub 3} by hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, K.H.; Kubis, M.; Handstein, A.; Gutfleisch, O.

    2000-05-10

    Hydrogen-induced amorphization (HIA) has received much attention as a method for the preparation of amorphous compounds since its discovery by Yeh et al. Meanwhile it has been observed for a large number of intermetallic compounds with C15, C23, B8{sub 2}, DO{sub 19} and L1{sub 2} structures. E.G. the C15 Laves-type compounds (MgCu{sub 2}-type structure) of rare earth (R) - transition metal (T) compounds RT{sub 2} show HIA for R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er. Aoki et al. postulated that new amorphizing compounds can be expected at high hydrogen pressures. In this work, the structural changes of SmFe{sub 3} (PuNi{sub 3}-type structure) during heating in high hydrogen pressures are reported.

  3. Solid-state amorphization of SmFe3 by hydrogenation

    International Nuclear Information System (INIS)

    Mueller, K.H.; Kubis, M.; Handstein, A.; Gutfleisch, O.

    2000-01-01

    Hydrogen-induced amorphization (HIA) has received much attention as a method for the preparation of amorphous compounds since its discovery by Yeh et al. Meanwhile it has been observed for a large number of intermetallic compounds with C15, C23, B8 2 , DO 19 and L1 2 structures. E.G. the C15 Laves-type compounds (MgCu 2 -type structure) of rare earth (R) - transition metal (T) compounds RT 2 show HIA for R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er. Aoki et al. postulated that new amorphizing compounds can be expected at high hydrogen pressures. In this work, the structural changes of SmFe 3 (PuNi 3 -type structure) during heating in high hydrogen pressures are reported

  4. Spontaneous polarization and pyroelectric effect in improper ferroelectrics-ferroelastics Gd2(MoO4)3 and Tb2(MoO4)3 at low temperature

    International Nuclear Information System (INIS)

    Matyjasik, S; Shaldin, Yu.V.

    2013-01-01

    Experimental dependencies for spontaneous polarization ΔP s (T) and pyroelectric coefficient γ s (T)for Gd 2 (MoO 4 ) 3 (GMO) and Tb 2 (MoO 4 ) 3 (TMO) reported here differs from those for intrinsic ferroelectrics. We found fundamental distinction in GMO and TMO samples behavior at their repolarization at the fixed temperatures 300 and 4.2 K. In TMO monodomainization temperature does not affect experimental data, while in GMO monodomainization at 4.2 K results in increase of ΔP s (T) by order of magnitude at 85 K and γ s (T) dependence shows well-defined anomalies, reaching a record magnitude of 3 centre dot 10 -4 C/(m 2 centre dot K) at T = 25 K. At T = 200 K the pyroelectric coefficients values are -1.45 centre dot 10 -6 C/(m 2 centre dot K) and-1.8 centre dot 10 -6 C/(m 2 centre dot K). Taking into account our data, results related to transformation of structure in (001) plane and symmetry reasons we suggested crystallographic model of GMO type improper ferroelectric. It is formed by four meso-tetrahedrons constructed of three coordination tetrahedrons MO 4 (a, b and c types). In the framework of this model we discuss the physical meaning of pseudodeviator Q 12 *, coefficient, that initiate the phase transition at T > 433 K from noncentrosymmetric phase (mm2) to another one (4-bar2m).

  5. Reaction kinetics of H{sub 2}, O{sub 2}, and H{sub 2}O with rare earths (Y, La, Ce, Pr, Nd, Gd, Tb, Dy, and Er) at 298 K

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, M.; Ohata, Y. [Course of Applied Science, Graduate School of Engineering, Tokai University, 4-1-1 Kita-Kaname, Hiratsuka, Kanagawa 259-1292 (Japan); Uchida, H., E-mail: huchida@keyaki.cc.u-tokai.ac.jp [Course of Applied Science, Graduate School of Engineering, Tokai University, 4-1-1 Kita-Kaname, Hiratsuka, Kanagawa 259-1292 (Japan)

    2013-12-15

    Highlights: ► H{sub 2} molecules react with a clean surface of each RE sample at the highest reactivity even at 298 K. ► The H{sub 2} reactivity becomes reduced by the formation of dihydrides of each RE sample. ► The RE with a clean surface adsorb O{sub 2} more than one monolayer of O{sub 2} even at 298 K. ► The quantitative reactivity of the H atoms dissociated from H{sub 2}O was calculated. -- Abstract: High reactivity of rare earths (RE) with H{sub 2}, O{sub 2} and H{sub 2}O is well known even at room temperature. The formation of stable surface oxides/hydroxides on the surface is the one of serious problems in the production and use of materials containing RE. We have investigated the quantitative reactivities of H{sub 2}, O{sub 2}, and H{sub 2}O with the surface of Y, La, Ce, Pr, Nd, Gd, Tb, Dy, and Er under ultra high vacuum condition. The H{sub 2}, O{sub 2} and H{sub 2}O gases exhibited the highest reactivity on the clean surface of the RE at 298 K. This means that all gas molecules impinging the surface dissociate and chemisorbed. The O atoms dissociated from O{sub 2} adsorb to for oxides layers of the metals. The H atoms dissociated from H{sub 2} diffuse into the metals to form hydrides which were found to decrease the H{sub 2} reactivity. The H atoms dissociated form H{sub 2}O diffuse into the metals or form hydroxides of the metals. With increasing coverage of each gas molecules, the reactivity of each gas was decreased by several orders of magnitude.

  6. Investigation of the transport properties and compositions of the Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} series (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi)

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, Scott [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Yuan, Fang [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Kosuda, Kosuke; Kolodiazhnyi, Taras [Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Mozharivskyj, Yurij, E-mail: mozhar@mcmaster.ca [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada)

    2016-10-15

    The Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} phases (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi) were successfully prepared from high temperature reactions at 1225–1300 °C. These phases maintain the same structure types as the parent RE{sub 9}Pn{sub 5}O{sub 5} phases, except for a Ca/RE mixing. The study and preparation of these phases was motivated by the desire to shift the metallic type properties of the parent RE{sub 9}Pn{sub 5}O{sub 5} phases to a level more suitable for thermoelectric applications. Electrical resistivity measurements performed on pure, bulk samples indicated all phases to be narrow band gap semiconductors or semimetals, supporting the charge balanced electron count of the Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} composition. Unfortunately, all samples are too electrically resistive for any potential usage as thermoelectrics. Electronic band structure calculations performed on idealized RE{sub 9}Pn{sub 5}O{sub 5} structures revealed the presence of a pseudogap at the Fermi level, which is consistent with the observed electrical resistivity and Seebeck coefficient behavior. - Graphical abstract: Ca substitution in RE{sub 9}Pn{sub 5}O{sub 5} leads to charge-balanced Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} phases with semiconducting or semimetallic properties. - Highlights: • The RE{sub 9}Pn{sub 5}O{sub 5} structure may be stabilized with calcium substitution in the form of Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5}. • The Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} phases maintain the parent P 4/n structure, albeit with Ca/RE mixing. • The Ca{sub 2}RE{sub 7}Sb{sub 5}O{sub 5} phases behave as semiconductors while Ca{sub 2}RE{sub 7}Bi{sub 5}O{sub 5} are semimetals with electron-electron correlations. • Electronic structure calculations yield a semimetal-like density of states for both Ca{sub 2}RE{sub 7}Sb{sub 5}O{sub 5} and Ca{sub 2}RE{sub 7}Bi{sub 5}O{sub 5}.

  7. Synthesis, structure, luminescent, and magnetic properties of carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2] (Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato).

    Science.gov (United States)

    Ehama, Kiyomi; Ohmichi, Yusuke; Sakamoto, Soichiro; Fujinami, Takeshi; Matsumoto, Naohide; Mochida, Naotaka; Ishida, Takayuki; Sunatsuki, Yukinari; Tsuchimoto, Masanobu; Re, Nazzareno

    2013-11-04

    Carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2]·solvent were synthesized through atmospheric CO2 fixation reaction of [Zn(II)L(n)(H2O)2]·xH2O, Ln(III)(NO3)3·6H2O, and triethylamine, where Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato. Each Zn(II)2Ln(III)2 structure possessing an inversion center can be described as two di-μ-phenoxo-bridged {Zn(II)L(n)Ln(III)(NO3)} binuclear units bridged by two carbonato CO3(2-) ions. The Zn(II) ion has square pyramidal coordination geometry with N2O2 donor atoms of L(n) and one oxygen atom of a bridging carbonato ion at the axial site. Ln(III) ion is coordinated by nine oxygen atoms consisting of four from the deprotonated Schiff-base L(n), two from a chelating nitrate, and three from two carbonate groups. The temperature-dependent magnetic susceptibilities in the range 1.9-300 K, field-dependent magnetization from 0 to 5 T at 1.9 K, and alternating current magnetic susceptibilities under the direct current bias fields of 0 and 1000 Oe were measured. The magnetic properties of the Zn(II)2Ln(III)2 complexes are analyzed on the basis of the dicarbonato-bridged binuclear Ln(III)-Ln(III) structure, as the Zn(II) ion with d(10) electronic configuration is diamagnetic. ZnGd1 (L(1)) and ZnGd2 (L(2)) show a ferromagnetic Gd(III)-Gd(III) interaction with J(Gd-Gd) = +0.042 and +0.028 cm(-1), respectively, on the basis of the Hamiltonian H = -2J(Gd-Gd)ŜGd1·ŜGd2. The magnetic data of the Zn(II)2Ln(III)2 complexes (Ln(III) = Tb(III), Dy(III)) were analyzed by a spin Hamiltonian including the crystal field effect on the Ln(III) ions and the Ln(III)-Ln(III) magnetic interaction. The Stark splitting of the ground state was so evaluated, and the energy pattern indicates a strong easy axis (Ising type) anisotropy. Luminescence spectra of Zn(II)2Tb(III)2 complexes were observed, while those

  8. Effect of mixing RE elements (Nd, Sm, Gd, Eu, Y, Yb) on the RE2BaCuO5/Nd4-2xBa2+2xCu2-xO10-2x phases in RE cuprate high-Tc superconductors

    International Nuclear Information System (INIS)

    Langhorn, J.B.; Black, M.A.; McGinn, P.J.

    1999-01-01

    The phases RE 2 BaCuO 5 /RE 4 Ba 2 Cu 2 O 10 phases (where RE is a mixture of Nd, Sm, Gd, Eu, Y and Yb) have been synthesized in an oxygen atmosphere and subsequently characterized. The mixing of RE elements which inherently form the RE 2 BaCuO 5 phase through the peritectic decomposition of REBa 2 Cu 3 O 7-x (RE123) (i.e. Sm, Gd, Eu, Y, Yb), was observed to give homogeneous mixing of the elements in the 211 phase. In contrast it was found that on mixing Nd with other RE elements a mixture of the Nd 4-2x Ba 2+2x Cu 2-x O 10-2x (Nd422) and RE 2 BaCuO 5 (RE211) phases resulted. It was also observed that on mixing Nd with other REs a finite amount of the RE is substituted into the Nd422 phase and Nd into the RE211. (author)

  9. Octupole excitations in 146Sm

    International Nuclear Information System (INIS)

    Bizzeti, P.G.; Bizzetti-Sona, A.M.

    1998-01-01

    The mean lives of the lowest 9 - and 12 + states of 146 Sm have been measured by means of the RDM. Their (preliminary) values are r m (9 - )=0.97±0.05 ns and r m (12 + )=15±2 ps, respectively. The strengths of the collective E3 transitions of the 12 + →9 - →6 6 cascade are compared with the corresponding ones in 148 Gd

  10. 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...

  11. Testing for TB Infection

    Science.gov (United States)

    ... Adverse Events TB Treatment of Persons Living with HIV TB Treatment and Pregnancy TB Treatment for Children Drug-Resistant TB Research TB Epidemiologic Studies Consortium Research Projects Publications TB Trials Consortium Study ...

  12. Luminescence and magnetic properties of novel nanoparticle-sheathed 3D Micro-Architectures of Fe0.5R0.5(MoO4)1.5:Ln3+ (R = Gd3+, La3+), (Ln = Eu, Tb, Dy) for bifunctional application

    Science.gov (United States)

    Krishnan, Rajagopalan; Thirumalai, Jagannathan; Kathiravan, Arunkumar

    2015-01-01

    For the first time, we report the successful synthesis of novel nanoparticle-sheathed bipyramid-like and almond-like Fe0.5R0.5(MoO4)1.5:Ln3+ (R = Gd3+, La3+), (Ln = Eu, Tb, Dy) 3D hierarchical microstructures through a simple disodium ethylenediaminetetraacetic acid (Na2EDTA) facilitated hydrothermal method. Interestingly, time-dependent experiments confirm that the assembly-disassembly process is responsible for the formation of self-aggregated 3D architectures via Ostwald ripening phenomena. The resultant products are characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), photoluminescence (PL), and magnetic measurements. The growth and formation mechanisms of the self-assembled 3D micro structures are discussed in detail. To confirm the presence of all the elements in the microstructure, the energy loss induced by the K, L shell electron ionization is observed in order to map the Fe, Gd, Mo, O, and Eu components. The photo luminescence properties of Fe0.5R0.5(MoO4)1.5 doped with Eu3+, Tb3+, Dy3+ are investigated. The room temperature and low temperature magnetic properties suggest that the interaction between the local-fields introduced by the magnetic Fe3+ ions and the R3+ (La, Gd) ions in the dodecahedral sites determine the magnetism in Fe0.5R0.5(MoO4)1.5:Eu3+. This work provides a new approach to synthesizing the novel Fe0.5R0.5(MoO4)1.5:Ln3+ for bi-functional magnetic and luminescence applications.

  13. Synthesis and magneto-structural studies on a new family of carbonato bridged 3d-4f complexes featuring a [CoLn(CO3)] (Ln = La, Gd, Tb, Dy and Ho) core: slow magnetic relaxation displayed by the cobalt(ii)-dysprosium(iii) analogue.

    Science.gov (United States)

    Majee, Mithun Chandra; Towsif Abtab, Sk Md; Mondal, Dhrubajyoti; Maity, Manoranjan; Weselski, Marek; Witwicki, Maciej; Bieńko, Alina; Antkowiak, Michał; Kamieniarz, Grzegorz; Chaudhury, Muktimoy

    2018-03-06

    A new family of [3 + 3] hexanuclear 3d-4f complexes [(μ 3 -CO 3 ){Co II Ln III L(μ 3 -OH)(OH 2 )} 3 ]-(ClO 4 )·mC 2 H 5 OH·nH 2 O (1-5) [Ln = La (1), Gd (2), Tb (3), Dy (4), and Ho (5)] have been prepared in moderate to high yields (62-78%) following a self-assembly reaction between the ligand 6,6',6''-(nitrilotris(methylene))tris-(2-methoxy-4-methylphenol) (H 3 L), Co(OAc) 2 ·4H 2 O and the lanthanide ion precursors in the mandatory presence of tetrabutylammonium hydroxide. During the reaction, atmospheric carbon dioxide is fixed in the product molecule as a bridging carbonato ligand which connects all the three lanthanide centers of this molecular assembly through a rare η 2 :η 2 :η 2 -μ 3 mode of bridging as revealed from X-ray crystallography. The metal centers in all these compounds, except the Gd III analogue (2), are coupled in antiferromagnetic manner while the nature of coupling in the CoGd complex is ferromagnetic. DFT calculations revealed that this ferromagnetic interaction occurs most likely by the Co II -Gd III superexchange, mediated via the bridging oxygen atoms. Only the Co II -Dy III compound (4) displayed a slow relaxation of the magnetization at a very low temperature as established by AC susceptibility measurements. The data provides an estimation of the activation energy U/k B = 9.2 K and the relaxation time constant τ 0 = 1.0 × 10 -7 s.

  14. Determination of '14 MeV' cross sections for (n,p)-, (n,α)-, (n,2n)-, and (n,np + pn + d)-reactions on the elements Sc, Ni, Ge, Pd, Cd, Sm, Dy, Gd, and Yb in consideration of the 'effective' n-energy spectra

    International Nuclear Information System (INIS)

    Weigel, H.; Michel, R.; Herr, W.

    1975-01-01

    A total of 24 cross sections was determined for (n,p)-, (n,α)-, (n,2n)-, and (n,np + pn + d)-reactions of fast (so called '14 MeV') neutrons on the elements Sc, Ni, Ge, Pd, Cd, Sm, Dy, Gd, and Yb. 58 Ni(n,p) 58 Co served as monitor reaction. It is a special feature of this work that calculated neutron energy spectra for the '14 MeV' n-tube (Type Philips 18602) were considered, thus enabling us to supply each individual sigma-value with the respective n-energy distribution. On the basis of an extensive literature search (up to the beginning of 1973) the sigma-data were compared with experimental results of other authors and with those deduced from the statistical model. For some nuclides (e.g. 58 Ni, 154 Gd, 168 Yb, 176 Yb) it was possible to show the limits of applicability of the latter model. Summarizing, 12 cross sections and 3 isomeric ratios, nearly all of which belong to reaction products with rather long half-lifes, were determined for the first time. (orig.) [de

  15. Determination of '14 MeV' cross sections for (n,p), (n,. cap alpha. ), (n,2n), and (n,np + pn + d) reactions on the elements Sc, Ni, Ge, Pd, Cd, Sm, Dy, Gd, and Yb in consideration of the 'effective' n-energy spectra

    Energy Technology Data Exchange (ETDEWEB)

    Weigel, H; Michel, R; Herr, W [Koeln Univ. (F.R. Germany). Inst. fuer Kernchemie

    1975-01-01

    A total of 24 cross sections was determined for (n,p), (n,..cap alpha..), (n,2n), and (n,np + pn + d) reactions of fast (so called '14-MeV') neutrons on the elements Sc, Ni, Ge, Pd, Cd, Sm, Dy, Gd, and Yb. /sup 58/Ni(n,p)/sup 58/Co served as monitor reaction. It is a special feature of this work that calculated neutron energy spectra for the '14 MeV' n-tube (Type Philips 18602) were considered; each individual sigma value could thus be supplied with the respective n-energy distribution. On the basis of an extensive literature search (up to the beginning of 1973), the sigma data were compared with experimental results of other authors and with those deduced from the statistical model. For some nuclides (e.g. /sup 58/Ni, /sup 154/Gd, /sup 168/Yb, /sup 176/Yb) it was possible to show the limits of applicability of the latter model. Summarizing, 12 cross sections and 3 isomeric ratios, nearly all of which belong to reaction products with rather long half-lifes, were determined for the first time.

  16. Superconductivity in ABa 2Cu 3O 7-x compounds, where A = (R 1) x(R 2) 1-x and R1, R2 = Y, Sm, Eu, Gd, Tb, Dy, Yb, Zr, Nb AND La

    Science.gov (United States)

    Poddar, A.; Mandal, P.; Choudhury, P.; Das, A. N.; Ghosh, B.

    1988-06-01

    The electrical resistance has been measured for the titled compounds. All the compounds show superconductivity at about 90 K except La-system whose superconducting behavior depends much on the preparation procedure. Magnetization measurements has been made at 77 K and the Hmax (field at which negative magnetization is maximum) values for the above systems are in the range 170 - 320 Oe.

  17. 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)

  18. 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

  19. 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.

  20. Treatment: Latent TB Infection (LTBI) and TB Disease

    Science.gov (United States)

    ... Adverse Events TB Treatment of Persons Living with HIV TB Treatment and Pregnancy TB Treatment for Children Drug-Resistant TB Research TB Epidemiologic Studies Consortium Research Projects Publications TB Trials Consortium Study ...

  1. 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

  2. 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.

  3. In vivo radiochemical properties of Tb-149: A new radiolanthanide for targeted cancer therapy

    International Nuclear Information System (INIS)

    Allen, B.J.; Beyer, G.J.; Morel, C.H.; Aleksandrova, Y.; Jahn, S.

    1996-01-01

    Full text: 149 Tb (4.15 h) decays by the emission of both 3.9 MeV alpha particles (17% branching) and positrons (4% branch), and uniquely combines both therapeutic and PET diagnostic properties. In this paper we report the production route, systemic studies of radio-lanthanides with ethylenediaminetetra methylene phosphonate (EDTMP) ligand, and the first 149 Tb phantom studies using PET. The radio-lanthanides used in this study were produced at the ISOLDE (isotope separator on-line) facility at CERN. They are produced carrier free, isotopically and chemically separated (isobaric separation using cation exchange chromatography) in a form suitable for protein labelling. Batches up to 20 mCi of 1 4 9T b are available. We have established relationships between biokinetics, EDTMP concentration, and the ionic radius of the radiolanthanide used. The tumour to liver ratio in mice reaches a maximum value at 1 mM 10 mM and decreases from 10 by almost two decades according to the ionic radius of the lanthanide. For Tb, a tumour to liver ratio of 5 can be obtained, similar to Gd. No significant differences in the uptake in bone for all lanthanides in the EDTMP system were observed. A fast blood clearance allows clear bone images to be obtained via PET at 60-90 min post-injection, as shown with rabbits using 142 Sm-EDTMP. The first phantom PET studies with 149 Tb are also reported. We conclude that the fast biokinetics and the alpha decay mode open up new possibilities for a more efficient endo-radionuclide therapy using EDTMP. The high purity of the 149T b (isotopically separated and carrier free) produced in this way makes it very suitable for the labelling of octretides

  4. 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.

  5. 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.

  6. 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 ...

  7. 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.

  8. Carbonato-bridged Ni(II)2Ln(III)2 (Ln(III) = Gd(III), Tb(III), Dy(III)) complexes generated by atmospheric CO2 fixation and their single-molecule-magnet behavior: [(μ4-CO3)2{Ni(II)(3-MeOsaltn)(MeOH or H2O)Ln(III)(NO3)}2]·solvent [3-MeOsaltn = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato].

    Science.gov (United States)

    Sakamoto, Soichiro; Fujinami, Takeshi; Nishi, Koshiro; Matsumoto, Naohide; Mochida, Naotaka; Ishida, Takayuki; Sunatsuki, Yukinari; Re, Nazzareno

    2013-06-17

    Atmospheric CO2 fixation of [Ni(II)(3-MeOsaltn)(H2O)2]·2.5H2O [3-MeOsaltn = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato], Ln(III)(NO3)3·6H2O, and triethylamine occurred in methanol/acetone, giving a first series of carbonato-bridged Ni(II)2Ln(III)2 complexes [(μ4-CO3)2{Ni(II)(3-MeOsaltn)(MeOH)Ln(III)(NO3)}2] (1Gd, 1Tb, and 1Dy). When the reaction was carried out in acetonitrile/water, it gave a second series of complexes [(μ4-CO3)2{Ni(II)(3-MeOsaltn)(H2O)Ln(III)(NO3)}2]·2CH3CN·2H2O (2Gd, 2Tb, and 2Dy). For both series, each Ni(II)2Ln(III)2 structure can be described as two di-μ-phenoxo-bridged Ni(II)Ln(III) binuclear units bridged by two carbonato CO3(2-) units to form a carbonato-bridged (μ4-CO3)2{Ni(II)2Ln(III)2} structure. The high-spin Ni(II) ion has octahedral coordination geometry, and the Ln(III) ion is coordinated by O9 donor atoms from Ni(II)(3-MeOsaltn), bidentate NO3(-), and one and two oxygen atoms of two CO3(2-) ions. The NO3(-) ion for the first series roughly lie on Ln-O(methoxy) bonds and are tilted toward the outside, while for the second series, the two oxygen atoms roughly lie on one of the Ln-O(phenoxy) bonds due to the intramolecular hydrogen bond. The temperature-dependent magnetic susceptibilities indicated a ferromagnetic interaction between the Ni(II) and Ln(III) ions (Ln(III) = Gd(III), Tb(III), Dy(III)) for all of the complexes, with a distinctly different magnetic behavior between the two series in the lowest-temperature region due to the Ln(III)-Ln(III) magnetic interaction and/or different magnetic anisotropies of the Tb(III) or Dy(III) ion. Alternating-current susceptibility measurements under the 0 and 1000 Oe direct-current (dc) bias fields showed no magnetic relaxation for the Ni(II)2Gd(III)2 complexes but exhibited an out-of-phase signal for Ni(II)2Tb(III)2 and Ni(II)2Dy(III)2, indicative of slow relaxation of magnetization. The energy barriers, Δ/kB, for the spin flipping were estimated from the Arrhenius

  9. Magnetic ordering in Sc{sub 2}CoSi{sub 2}-type R{sub 2}FeSi{sub 2} (R=Gd, Tb) and R{sub 2}CoSi{sub 2} (R=Y, Gd–Er) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Knotko, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Pani, M. [Department of Chemistry, University of Genova, Via Dodecaneso 31, 16146 Genova (Italy); Institute SPIN-CNR, C. Perrone 24, 16152 Genova (Italy); Nirmala, R. [Indian Institute of Technology Madras, Chennai 600036 (India); Quezado, S.; Malik, S.K. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59082-970 (Brazil)

    2016-09-01

    Magnetic and magnetocaloric properties of Sc{sub 2}CoSi{sub 2}-type R{sub 2}TSi{sub 2} (R=Gd–Er, T=Fe, Co) compounds have been studied using magnetization data. These indicate the presence of mixed ferromagnetic and antiferromagnetic interactions in these compounds. One observes a ferromagnetic transition followed by an antiferromagnetic order and a further possible spin-reorientation transition at low temperatures. Compared to Gd{sub 2}{Fe, Co}Si{sub 2}, the Tb{sub 2}FeSi{sub 2} and {Tb–Er}{sub 2}CoSi{sub 2} compounds exhibit remarkable hysteresis (for e.g. Tb{sub 2}FeSi{sub 2} shows residual magnetization M{sub res}/Tb=2.45 μ{sub B}, coercive field H{sub coer}=14.9 kOe, and critical field H{sub crit}~5 kOe at 5 K) possibly due to the magnetocrystalline anisotropy of the rare earth. The R{sub 2}{Fe, Co}Si{sub 2} show relatively small magnetocaloric effect (i.e. isothermal magnetic entropy change, ΔS{sub m}) around the magnetic transition temperature: the maximal value of MCE is demonstrated by Ho{sub 2}CoSi{sub 2} (ΔS{sub m}=−8.1 J/kg K at 72 K and ΔS{sub m}=−9.4 J/kg K at 23 K in field change of 50 kOe) and Er{sub 2}CoSi{sub 2} (ΔS{sub m}=−13.6 J/kg K at 32 K and ΔS{sub m}=−8.4 J/kg K at 12 K in field change of 50 kOe). - Highlights: • {Gd–Er}{sub 2}{Fe, Co}Si{sub 2} show high-temperature ferromagnetic-type transitions. • {Gd–Er}{sub 2}{Fe, Co}Si{sub 2} show low-temperature spin-reorientation transitions. • Tb{sub 2}FeSi{sub 2} and {Tb–Er}{sub 2}CoSi{sub 2} compounds exhibit low-temperature hysteresis. • Tb{sub 2}FeSi{sub 2} shows M{sub res}/Tb=2.45 μ{sub B}, H{sub coer}=14.9 kOe and H{sub crit} ~5 kOe at 5 K • Considerable magnetocaloric effect is exhibited by Ho{sub 2}CoSi{sub 2} and Er{sub 2}CoSi{sub 2}.

  10. 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.))

  11. Strategisch management (SM)

    NARCIS (Netherlands)

    Nagel, A.P.; Vercouteren, W.J.J.C.; Hoek, van der N.; Lohman, T.A.M.; Vermeulen, N.

    1996-01-01

    Kernbegrippen die bij de discussie van strategisch management (SM) aan de orde komen, zijn productinnovatie op ondernemingsniveau (oftewel strategische productinnovatie, SPI) en technologiestrategie. In dit artikel wordt een raamwerk van SM geintroduceerd. Daartoe worden de verschillende fasen van

  12. Synthesis and luminescence properties of BaTiO3:RE (RE = Gd , Dy ...

    Indian Academy of Sciences (India)

    thermoluminescence (TL) properties of BaTiO3 samples doped with Gd3+, Dy3+, Tb3+ and Lu3+ were investigated. ... electron microscope using an accelerating voltage of 20 kV. .... doping of 1% mole Gd3+ ion into the BaTiO3 compound.

  13. Tuberculosis Facts - Exposure to TB

    Science.gov (United States)

    Tuberculosis (TB) Facts Exposure to TB What is TB? “TB” is short for a disease called tuberculosis. TB is spread through the air from one ... Viral Hepatitis, STD, and TB Prevention Division of Tuberculosis Elimination

  14. Tuberculosis Facts - Testing for TB

    Science.gov (United States)

    Tuberculosis (TB) Facts Testing for TB What is TB? “TB” is short for a disease called tuberculosis. TB is spread through the air from one ... Viral Hepatitis, STD, and TB Prevention Division of Tuberculosis Elimination

  15. Lanthanide 4f-level location in AVO4:Ln3+ (A = La, Gd, Lu) crystals

    NARCIS (Netherlands)

    Krumpel, A.H.; Van der Kolk, E.; Cavalli, E.; Boutinaud, P.; Bettinelli, M.; Dorenbos, P.

    2009-01-01

    The spectral properties of LaVO4, GdVO4 and LuVO4 crystals doped with Ce3+, Pr3+, Eu3+ or Tb3+ have been investigated in order to determine the position of the energy levels relative to the valence and conduction bands of the hosts along the trivalent and divalent lanthanide series. Pr3+ and Tb3+

  16. Multi-quasiparticle excitations in 145Tb

    International Nuclear Information System (INIS)

    Zheng Yong; Zhou Xiaohong; Zhang Yuhu; Liu Minliang; Guo Yingxiang; Lei Xiangguo; Kusakari, H.; Sugawara, M.

    2004-01-01

    High-spin states in 145 Tb have been populated using the 118 Sn( 32 S, 1p4n) reaction at a beam energy of 165 MeV. The level scheme of 145 Tb has been established for the first time. The level scheme shows characteristics of spherical or slightly oblate nucleus. Based on the systematic trends of the level structure in the neighboring N=80 isotones, the level structure in 145 Tb below 2 MeV excitation is well explained by coupling an h 11/2 valence proton to the even-even 144 Gd core. Above 2 MeV excitation, most of the yrast levels are interpreted with multi-quasiparticle shell-model configurations. (authors)

  17. 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.

  18. 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)

  19. Find TB. Treat TB. Working together to eliminate TB.

    Centers for Disease Control (CDC) Podcasts

    2014-02-26

    In this podcast, Dr. Sundari Mase, Medical Team Lead in the Field Services and Evaluation Branch in the Division of Tuberculosis Elimination, discusses World TB Day and the 2014 theme.  Created: 2/26/2014 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 2/26/2014.

  20. Enhancing Sm{sup 3+} red emission via energy transfer from Bi{sup 3+}→Sm{sup 3+} based on terbium bridge mechanism in Ca{sub 2}Al{sub 2}SiO{sub 7} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Li, Minhong; Wang, LiLi; Ran, Weiguang; Ren, Chunyan; Song, Zeling; Shi, Jinsheng, E-mail: jsshiqn@aliyun.com

    2017-04-15

    Currently, the key change for white-LED is to improve the luminescence efficiency of red phosphor. Sm{sup 3+} activated phosphor was considered due to suitable emission position of red light. However, the luminescence intensity in the red region is weak. For enhancing red-emitting of Sm{sup 3+}, Bi{sup 3+} and Tb{sup 3+} ions were introduced into Ca{sub 2}Al{sub 2}SiO{sub 7}:Sm{sup 3+} phosphors based on the concept of energy transfer. For Ca{sub 2}Al{sub 2}SiO{sub 7}:Bi{sup 3+}, Sm{sup 3+} samples, it can be observed that the energy transfer process was blocked. Hence, Tb{sup 3+} was introduced into Ca{sub 2}Al{sub 2}SiO{sub 7}:Bi{sup 3+}, Sm{sup 3+} samples to increase Sm{sup 3+} luminescence intensity based on Bi{sup 3+}→Tb{sup 3+}→Sm{sup 3+} energy transfer process. Compared with Sm{sup 3+} single-doped Ca{sub 2}Al{sub 2}SiO{sub 7} phosphor, the luminescence intensity of Sm{sup 3+} was enhanced by 2.6 times. It can be found that Tb{sup 3+} ions play a role of storing the energy or transfer bridge from Bi{sup 3+}→ Sm{sup 3+} by investigating the Ca{sub 2}Al{sub 2}SiO{sub 7}:Bi{sup 3+}, Tb{sup 3+} and Ca{sub 2}Al{sub 2}SiO{sub 7}:Tb{sup 3+}, Sm{sup 3+} energy transfer mechanism. All these results suggest that terbium branch mechanism plays an important role on enhancing activators luminescence intensity.

  1. The low-energy β(-) and electron emitter (161)Tb as an alternative to (177)Lu for targeted radionuclide therapy.

    Science.gov (United States)

    Lehenberger, Silvia; Barkhausen, Christoph; Cohrs, Susan; Fischer, Eliane; Grünberg, Jürgen; Hohn, Alexander; Köster, Ulli; Schibli, Roger; Türler, Andreas; Zhernosekov, Konstantin

    2011-08-01

    The low-energy β(-) emitter (161)Tb is very similar to (177)Lu with respect to half-life, beta energy and chemical properties. However, (161)Tb also emits a significant amount of conversion and Auger electrons. Greater therapeutic effect can therefore be expected in comparison to (177)Lu. It also emits low-energy photons that are useful for gamma camera imaging. The (160)Gd(n,γ)(161)Gd→(161)Tb production route was used to produce (161)Tb by neutron irradiation of massive (160)Gd targets (up to 40 mg) in nuclear reactors. A semiautomated procedure based on cation exchange chromatography was developed and applied to isolate no carrier added (n.c.a.) (161)Tb from the bulk of the (160)Gd target and from its stable decay product (161)Dy. (161)Tb was used for radiolabeling DOTA-Tyr3-octreotate; the radiolabeling profile was compared to the commercially available n.c.a. (177)Lu. A (161)Tb Derenzo phantom was imaged using a small-animal single-photon emission computed tomography camera. Up to 15 GBq of (161)Tb was produced by long-term irradiation of Gd targets. Using a cation exchange resin, we obtained 80%-90% of the available (161)Tb with high specific activity, radionuclide and chemical purity and in quantities sufficient for therapeutic applications. The (161)Tb obtained was of the quality required to prepare (161)Tb-DOTA-Tyr3-octreotate. We were able to produce (161)Tb in n.c.a. form by irradiating highly enriched (160)Gd targets; it can be obtained in the quantity and quality required for the preparation of (161)Tb-labeled therapeutic agents. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. 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

  3. Two hexagonal series of lanthanoid(III) oxide fluoride selenides.: M{sub 6}O{sub 2}F{sub 8}Se{sub 3} (M = La - Nd) and M{sub 2}OF{sub 2}Se (M = Nd, Sm, Gd - Ho)

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Dirk D.; Grossholz, Hagen; Wolf, Sarah; Schleid, Thomas [Institut fuer Anorganische Chemie, Universitaet Stuttgart (Germany); Janka, Oliver [Institut fuer Anorganische Chemie, Universitaet Stuttgart (Germany); Institut fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Universitaet Muenster (Germany); Mueller, Alexander C. [Institut fuer Anorganische Chemie, Universitaet Stuttgart (Germany); Institut fuer Textilchemie und Chemiefasern, Denkendorf (Germany)

    2015-09-15

    Two hexagonal series of lanthanoid(III) oxide fluoride selenides with similar structure types can be obtained by the reaction of the components MF{sub 3}, M{sub 2}O{sub 3}, M, and Se in sealed niobium tubes at 850 C using CsI as fluxing agent. The compounds with the lighter and larger representatives (M = La - Nd) occur with the formula M{sub 6}O{sub 2}F{sub 8}Se{sub 3}, whereas with the heavier and smaller ones (M = Nd, Sm, Gd - Ho) their composition is M{sub 2}OF{sub 2}Se. For both systems single-crystal determinations were used in all cases. The compounds crystallize in the hexagonal crystal system (space group: P6{sub 3}/m) with lattice parameters of a = 1394-1331 pm and c = 403-372 pm (Z = 2 for M{sub 6}O{sub 2}F{sub 8}Se{sub 3} and Z = 6 for M{sub 2}OF{sub 2}Se). The (M1){sup 3+} cations show different square antiprismatic coordination spheres with or without an extra capping fluoride anion. All (M2){sup 3+} cations exhibit a ninefold coordination environment shaped as tricapped trigonal prism. In both structure types the Se{sup 2-} anions are sixfold coordinated as trigonal prisms of M{sup 3+} cations, being first condensed by edges to generate trimeric units and then via faces to form strands running along [001]. The light anions reside either in threefold triangular or in fourfold tetrahedral cationic coordination. For charge compensation, both structures have to contain a certain amount of oxide besides fluoride anions. Since F{sup -} and O{sup 2-} can not be distinguished by X-ray diffraction, bond-valence calculations were used to address the problem of their adjunction to the available crystallographic sites. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Mycobacteria and TB

    National Research Council Canada - National Science Library

    Kaufmann, S. H. E. (Stephan H. E.); Hahn, Helmut

    2003-01-01

    .... Scientists investigating the epidemiology, immunology and molecular biology of TB or engaged in vaccine and drug development as well as physicians and social workers treating TB patients will benefit...

  5. 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.

  6. Magnetic properties of Tb1-xSmxMn2Si2 silicides

    International Nuclear Information System (INIS)

    Kilic, A.; Kervan, S.; Gencer, A.

    2005-01-01

    The structural and magnetic properties of polycrystalline Tb 1-x Sm x Mn 2 Si 2 (0= 2 Si 2 -type structure with the space group I4/mmm. Substitution of Sm for Tb leads to a linear increase of the lattice constants and the unit cell volume. The lattice constants and the unit cell volume obey Vegard's law. At low temperatures, the rare earth sublattice orders and reconfigures the ordering in the Mn sublattice. The Neel temperature T N (Mn) determined by DSC technique decreases linearly with increase in Sm content x. The results are collected in an x-T magnetic-phase diagram

  7. Questions and Answers about TB

    Science.gov (United States)

    ... disease. Introduction Testing and Treatment TB Disease Glossary Introduction Introduction What is TB? Why is TB still ... chest x-ray is made by exposing a film to x-rays that pass through the chest. ...

  8. TB in Captive Elephants

    Centers for Disease Control (CDC) Podcasts

    2017-04-27

    Dr. Barry Kreiswirth, founding director of the Public Health Research Institute, TB Center, at Rutgers University, discusses TB in three captive elephants.  Created: 4/27/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 4/27/2017.

  9. Gd-Ni-Si system

    International Nuclear Information System (INIS)

    Bodak, O.I.; Shvets, A.F.

    1983-01-01

    By X-ray phase analysis method isothermal cross section of phase diagram of the Gd-Ni-Si system at 870 K is studied. The existence of nine previously known compounds (GdNisub(6.72)Sisub(6.28), GdNi 10 Si 2 , GdNi 5 Si 3 , GdNi 4 Si, GdNi 2 Si 2 , GdNiSi 3 , GdNiSi 2 , Gd 3 Ni 6 Si 2 and GdNiSi) is confirmed and three new compounds (GdNisub(0.2)Sisub(1.8), Gdsub(2)Nisub(1-0.8)Sisub(1-1.2), Gd 5 NiSi 4 ) are found. On the base of Gd 2 Si 3 compound up to 0.15 at. Ni fractions, an interstitial solid solution is formed up to 0.25 at Ni fractions dissolution continues of substitution type. The Gd-Ni-Si system is similar to the Y-Ni-Si system

  10. Tuberculosis Facts - TB and HIV/AIDS

    Science.gov (United States)

    Tuberculosis (TB) Facts TB and HIV/AIDS What is TB? “TB” is short for a disease called tuberculosis. TB is spread through the air from one ... Viral Hepatitis, STD, and TB Prevention Division of Tuberculosis Elimination

  11. Superconductivity and magnetism in Ir-doped GdFeAsO

    International Nuclear Information System (INIS)

    Cui, Y.J.; Chen, Y.L.; Cheng, C.H.; Yang, Y.; Jiang, J.; Wang, Y.Z.; Zhang, Y.; Zhao, Y.

    2010-01-01

    The 5d-transition metal, Ir has successfully been doped at Fe site and induced superconductivity in GdFeAsO at T c = 18.9 K and ∼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 0.8 Ir 0.2 AsO was extrapolated to around 24 T, much smaller than that of F-doped GdFeAsO owing to a relatively low T c and small value of dH c2 /dT.

  12. The volumetric and thermochemical properties of YCl{sub 3}(aq), YbCl{sub 3}(aq), DyCl{sub 3}(aq), SmCl{sub 3}(aq), and GdCl{sub 3}(aq) at T=(288.15, 298.15, 313.15, and 328.15) K and p=0.1 MPa[Trivalent metal chlorides; Densities; Heat capacities; Single ion properties; Calorimetry; Densimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hakin, Andrew W. E-mail: hakin@uleth.ca; Lukacs, Michael J.; Liu, Jin Lian; Erickson, Kristy

    2003-11-01

    Relative densities and massic heat capacities have been measured for acidified aqueous solutions of YCl{sub 3}(aq), YbCl{sub 3}(aq), DyCl{sub 3}(aq), SmCl{sub 3}(aq), and GdCl{sub 3}(aq) at T=(288.15, 298.15, 313.15, and 328.15) K and p=0.1 MPa. These measurements have been used to calculate experimental apparent molar volumes and heat capacities which, when used in conjunction with Young's rule, were used to calculate the apparent molar properties of the aqueous chloride salt solutions. The latter calculations required the use of volumetric and thermochemical data for aqueous solutions of hydrochloric acid that have been previously reported in the literature. The concentration dependences of the apparent molar properties have been modeled using Pitzer ion interaction equations to yield apparent molar volumes and heat capacities at infinite dilution. The temperature and concentration dependences of the apparent molar volumes and heat capacities of each trivalent salt system were modeled using modified Pitzer ion interaction equations. These equations utilized the revised Helgeson, Kirkham, and Flowers equations of state to model the temperature dependences of apparent molar volumes and heat capacities at infinite dilution. Calculated apparent molar volumes and heat capacities at infinite dilution have been used to calculate single ion properties for the investigated trivalent metal cations. These values have been compared to those previously reported in the literature. The differences between single ion values calculated in this study and those values calculated from thermodynamic data for aqueous perchlorate salts are also discussed.

  13. HIV and Tuberculosis (TB)

    Science.gov (United States)

    ... AIDS Drugs Clinical Trials Apps skip to content HIV and Opportunistic Infections, Coinfections, and Conditions Home Understanding ... 4 p.m. ET) Send us an email HIV and Tuberculosis (TB) Last Reviewed: June 14, 2018 ...

  14. Tuberculosis (TB): Treatment

    Science.gov (United States)

    ... Education & Training Home Conditions Tuberculosis (TB) Tuberculosis: Treatment Tuberculosis: Treatment Make an Appointment Refer a Patient Ask ... or bones is treated longer. NEXT: Preventive Treatment Tuberculosis: Diagnosis Tuberculosis: History Clinical Trials For more than ...

  15. Tuberculosis Facts - You Can Prevent TB

    Science.gov (United States)

    Tuberculosis (TB) Facts You Can Prevent TB What is TB? “TB” is short for a disease called tuberculosis. TB is spread through the air from one ... Viral Hepatitis, STD, and TB Prevention Division of Tuberculosis Elimination TB Facts: You Can Prevent TB What ...

  16. Tuberculosis Facts - TB Can Be Treated

    Science.gov (United States)

    Tuberculosis (TB) Facts TB Can Be Treated What is TB? “TB” is short for a disease called tuberculosis. TB is spread through the air from one ... Viral Hepatitis, STD, and TB Prevention Division of Tuberculosis Elimination Page 1 of 2 TB Facts: TB ...

  17. New tetragonal derivatives of cubic NaZn13-type structure: RNi6Si6 compounds, crystal structure and magnetic ordering (R=Y, La, Ce, Sm, Gd–Yb)

    International Nuclear Information System (INIS)

    Pani, M.; Manfrinetti, P.; Provino, A.; Yuan, Fang; Mozharivskyj, Y.; Morozkin, A.V.; Knotko, A.V.; Garshev, A.V.; Yapaskurt, V.O.; Isnard, O.

    2014-01-01

    Novel RNi 6 Si 6 compounds adopt the new CeNi 6 Si 6 -type structure for R=La–Ce (tP52, space group P4/nbm N 125-1) and new YNi 6 Si 6 -type structure for R=Y, Sm, Gd–Yb (tP52, space group P4 ¯ b2N 117) that are tetragonal derivative of NaZn 13 -type structure, like LaCo 9 Si 4 -type. The CeNi 6 Si 6 , GdNi 6 Si 6 , TbNi 6 Si 6 , DyNi 6 Si 6 and HoNi 6 Si 6 compounds are Curie–Weiss paramagnets down to ∼30 K, and do not order magnetically down to 5 K. However, the inverse paramagnetic susceptibility of LaNi 6 Si 6 does not follow Curie–Weiss law. The DyNi 6 Si 6 shows ferromagnetic-like saturation behaviour at 5 K in applied fields of 50 kOe, giving rise to a magnetic moment value of 6.5 μ B /f.u. in 50 kOe. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi 6 Si 6 with K=[±1/4, ±1/4, 0] wave vector below ∼10 K. - Graphical abstract: Novel (La, Ce)Ni 6 Si 6 compounds adopt the new CeNi 6 Si 6 -type structure and (Y, Sm, Gd–Yb) adopt the new YNi 6 Si 6 -type structure that are tetragonal derivative of NaZn 13 -type structure, like LaCo 9 Si 4 -type. The CeNi 6 Si 6 , GdNi 6 Si 6 , TbNi 6 Si 6 , DyNi 6 Si 6 and HoNi 6 Si 6 compounds are Curie–Weiss paramagnets down to ∼30 K, and do not order magnetically down to 4.2 K. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi 6 Si 6 with K=[±1/4, ±1/4, 0] wave vector below ∼10 K. Display Omitted - Highlights: • The new (La, Ce)Ni 6 Si 6 compounds adopt the new CeNi 6 Si 6 -type structure. • The new (Y, Sm, Gd–Yb)Ni 6 Si 6 compounds adopt the new YNi 6 Si 6 -type structure. • TbNi 6 Si 6 has square modulated c-collinear antiferromagnetic ordering below ∼10 K

  18. New tetragonal derivatives of cubic NaZn{sub 13}-type structure: RNi{sub 6}Si{sub 6} compounds, crystal structure and magnetic ordering (R=Y, La, Ce, Sm, Gd–Yb)

    Energy Technology Data Exchange (ETDEWEB)

    Pani, M.; Manfrinetti, P.; Provino, A. [INFM and Dipartimento di Chimica e Chimica Industriale, Universita‘ di Genova, Via Dodecaneso 31, 16146 Genova (Italy); Yuan, Fang; Mozharivskyj, Y. [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4M1 (Canada); Morozkin, A.V., E-mail: morozkin@general.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Knotko, A.V.; Garshev, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Isnard, O. [Université Grenoble Alpes, Inst NEEL, BP166, F-38042 Grenoble (France); CNRS, Institut NEEL, 25 rue des martyrs, F-38042 Grenoble (France)

    2014-02-15

    Novel RNi{sub 6}Si{sub 6} compounds adopt the new CeNi{sub 6}Si{sub 6}-type structure for R=La–Ce (tP52, space group P4/nbm N 125-1) and new YNi{sub 6}Si{sub 6}-type structure for R=Y, Sm, Gd–Yb (tP52, space group P4{sup ¯}b2N 117) that are tetragonal derivative of NaZn{sub 13}-type structure, like LaCo{sub 9}Si{sub 4}-type. The CeNi{sub 6}Si{sub 6}, GdNi{sub 6}Si{sub 6}, TbNi{sub 6}Si{sub 6}, DyNi{sub 6}Si{sub 6} and HoNi{sub 6}Si{sub 6} compounds are Curie–Weiss paramagnets down to ∼30 K, and do not order magnetically down to 5 K. However, the inverse paramagnetic susceptibility of LaNi{sub 6}Si{sub 6} does not follow Curie–Weiss law. The DyNi{sub 6}Si{sub 6} shows ferromagnetic-like saturation behaviour at 5 K in applied fields of 50 kOe, giving rise to a magnetic moment value of 6.5 μ{sub B}/f.u. in 50 kOe. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi{sub 6}Si{sub 6} with K=[±1/4, ±1/4, 0] wave vector below ∼10 K. - Graphical abstract: Novel (La, Ce)Ni{sub 6}Si{sub 6} compounds adopt the new CeNi{sub 6}Si{sub 6}-type structure and (Y, Sm, Gd–Yb) adopt the new YNi{sub 6}Si{sub 6}-type structure that are tetragonal derivative of NaZn{sub 13}-type structure, like LaCo{sub 9}Si{sub 4}-type. The CeNi{sub 6}Si{sub 6}, GdNi{sub 6}Si{sub 6}, TbNi{sub 6}Si{sub 6}, DyNi{sub 6}Si{sub 6} and HoNi{sub 6}Si{sub 6} compounds are Curie–Weiss paramagnets down to ∼30 K, and do not order magnetically down to 4.2 K. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi{sub 6}Si{sub 6} with K=[±1/4, ±1/4, 0] wave vector below ∼10 K. Display Omitted - Highlights: • The new (La, Ce)Ni{sub 6}Si{sub 6} compounds adopt the new CeNi{sub 6}Si{sub 6}-type structure. • The new (Y, Sm, Gd–Yb)Ni{sub 6}Si{sub 6} compounds adopt the new YNi{sub 6}Si{sub 6}-type structure. • TbNi{sub 6}Si

  19. 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.

  20. 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.

  1. Ultraviolet photoluminescence in Gd-doped silica and phosphosilicate fibers

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2017-04-01

    Full Text Available Optical fiber lasers operating in the near infrared and visible spectral regions have relied on the spectroscopic properties of rare earth ions such as Yb3+, Er3+, Tm3+, Nd3+, and Sm3+. Here, we investigate Gd3+ doping in phosphosilicate and pure silica fibers using solution doping and sol-gel techniques, respectively, for potential applications in the ultraviolet. Photoluminescence spectra for optical fiber bundles and fiber preforms were recorded and compared. Emissions at 312 nm (phosphosilicate and 314 nm (pure silica were observed when pumping to the Gd3+ 6DJ, 6IJ, and 6PJ = 5/2, 3/2 energy levels. Oxygen deficient center was observed in solution doping sample with a wide absorption band centered at around 248 nm not affecting pumping to 6IJ states.

  2. 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

  3. 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.

  4. TB or not TB?: a case of isolated testicular TB with scrotal involvement.

    LENUS (Irish Health Repository)

    Bhargava, A

    2009-06-01

    Despite the genitourinary tract being the most common site affected by extrapulmonary TB, isolated testicular TB remains a rare clinical entity. In patients with co-morbidities such as hepatic impairment, treatment proves a challenge, as first-line hepatotoxic pharmaceuticals are contraindicated. Here, we report a case of isolated testicular TB with scrotal involvement, on a background of hepatic dysfunction.

  5. Compensation scheme for online neutron detection using a Gd-covered CdZnTe sensor

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan, E-mail: jonathan.dumazert@cea.fr; Coulon, Romain; Kondrasovs, Vladimir; Boudergui, Karim

    2017-06-11

    The development of portable and personal neutron dosimeters requires compact and efficient radiation sensors. Gd-157, Gd-155 and Cd-113 nuclei present the highest cross-sections for thermal neutron capture among natural isotopes. In order to allow for the exploitation of the low and medium-energy radiative signature of the said captures, the contribution of gamma background radiation, falling into the same energy range, needs to be cancelled out. This paper introduces a thermal neutron detector based on a twin-dense semiconductor scheme. The neutron-sensitive channel takes the form of a Gd-covered CdZnTe crystal, a high density and effective atomic number detection medium. The background compensation will be carried out by means of an identical CdZnTe sensor with a Tb cover. The setting of a hypothesis test aims at discriminating the signal generated by the signature of thermal neutron captures in Gd from statistical fluctuations over the compensation of both independent channels. The measurement campaign conducted with an integrated single-channel chain and two metal Gd and Tb covers, under Cs-137 and Cf-252 irradiations, provides first quantitative results on gamma-rejection and neutron sensitivity. The described study of concept gives grounds for a portable, online-compatible device, operable in conventional to controlled environments.

  6. Structure-function analysis and genetic interactions of the SmG, SmE, and SmF subunits of the yeast Sm protein ring.

    Science.gov (United States)

    Schwer, Beate; Kruchten, Joshua; Shuman, Stewart

    2016-09-01

    A seven-subunit Sm protein ring forms a core scaffold of the U1, U2, U4, and U5 snRNPs that direct pre-mRNA splicing. Using human snRNP structures to guide mutagenesis in Saccharomyces cerevisiae, we gained new insights into structure-function relationships of the SmG, SmE, and SmF subunits. An alanine scan of 19 conserved amino acids of these three proteins, comprising the Sm RNA binding sites or inter-subunit interfaces, revealed that, with the exception of Arg74 in SmF, none are essential for yeast growth. Yet, for SmG, SmE, and SmF, as for many components of the yeast spliceosome, the effects of perturbing protein-RNA and protein-protein interactions are masked by built-in functional redundancies of the splicing machine. For example, tests for genetic interactions with non-Sm splicing factors showed that many benign mutations of SmG, SmE, and SmF (and of SmB and SmD3) were synthetically lethal with null alleles of U2 snRNP subunits Lea1 and Msl1. Tests of pairwise combinations of SmG, SmE, SmF, SmB, and SmD3 alleles highlighted the inherent redundancies within the Sm ring, whereby simultaneous mutations of the RNA binding sites of any two of the Sm subunits are lethal. Our results suggest that six intact RNA binding sites in the Sm ring suffice for function but five sites may not. © 2016 Schwer et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  7. Structure–function analysis and genetic interactions of the SmG, SmE, and SmF subunits of the yeast Sm protein ring

    Science.gov (United States)

    Schwer, Beate; Kruchten, Joshua; Shuman, Stewart

    2016-01-01

    A seven-subunit Sm protein ring forms a core scaffold of the U1, U2, U4, and U5 snRNPs that direct pre-mRNA splicing. Using human snRNP structures to guide mutagenesis in Saccharomyces cerevisiae, we gained new insights into structure–function relationships of the SmG, SmE, and SmF subunits. An alanine scan of 19 conserved amino acids of these three proteins, comprising the Sm RNA binding sites or inter-subunit interfaces, revealed that, with the exception of Arg74 in SmF, none are essential for yeast growth. Yet, for SmG, SmE, and SmF, as for many components of the yeast spliceosome, the effects of perturbing protein–RNA and protein–protein interactions are masked by built-in functional redundancies of the splicing machine. For example, tests for genetic interactions with non-Sm splicing factors showed that many benign mutations of SmG, SmE, and SmF (and of SmB and SmD3) were synthetically lethal with null alleles of U2 snRNP subunits Lea1 and Msl1. Tests of pairwise combinations of SmG, SmE, SmF, SmB, and SmD3 alleles highlighted the inherent redundancies within the Sm ring, whereby simultaneous mutations of the RNA binding sites of any two of the Sm subunits are lethal. Our results suggest that six intact RNA binding sites in the Sm ring suffice for function but five sites may not. PMID:27417296

  8. Optical isotype shifts of 146Sm and 151Sm

    International Nuclear Information System (INIS)

    Eastham, D.A.; Walker, P.M.; Griffith, J.A.R.; Evans, D.E.; England, J.G.; Grant, I.S.

    1984-01-01

    We have measured the optical isotope shifts of 146 Sm and 151 Sm by laser resonance fluorescence. From these measurements the changes in the mean square nuclear radii are: delta 2 > (A=144 to 146)=0.266(10) fm 2 , and delta 2 > (A=151 to 152)=0.262(10) fm 2 . These results, together with those of the stable isotopes, show that the average nuclear expansion of samarium can be accounted for by the liquid drop model with deformations. (orig.)

  9. AC susceptibility, XRD and DSC studies of Sm1-xGdxMn2Si2 silicides

    International Nuclear Information System (INIS)

    Kervan, S.; Kilic, A.; Gencer, A.

    2004-01-01

    X-ray powder diffraction, AC susceptibility and differential scanning calorimetry (DSC) studies were performed on the polycrystalline Sm 1-x Gd x Mn 2 Si 2 (0≤x≤1) compounds. All compounds investigated crystallize in the body-centered tetragonal ThCr 2 Si 2 -type structure with the space group I4/mmm. Substitution of Gd for Sm leads to a linear decrease of the lattice constants and the unit cell volume. The lattice constants and the unit cell volume obey Vegard's law. At low temperatures, the rare earth sublattice orders and reconfigures the ordering in the Mn sublattice. The samples with x=0.6 and 0.8 exhibit spin reorientation phenomenon. The Neel temperature T N (Mn) determined by DSC technique and the Curie temperature T C (RE) increase linearly with increasing Gd content x. The results are summarized in the x-T magnetic phase diagram

  10. Energy transfer processes in Tb(III)-dibenzoylmethanate complexes with phosphine oxide ligands

    International Nuclear Information System (INIS)

    Silva Junior, Francisco A.; Nascimento, Helenise A.; Pereira, Dariston K.S.; Teotonio, Ercules E.S.; Espinola, Jose Geraldo P.; Faustino, Wagner M.; Sa, Gilberto F.

    2013-01-01

    The Tb 3+ -β-diketonate complexes [Tb(DBM) 3 L], [Tb(DBM) 2 (NO 3 )L 2 ] and [Tb(DBM)(NO 3 ) 2 (HMPA) 2 ] (DBM = dibenzoylmethanate; L: TPPO triphenylphosphine oxide or HMPA=hexamethylphosphine oxide) were prepared and characterized by elemental analysis (CHN), complexometric titration with EDTA and Fourier transform infrared (FTIR) spectroscopy, and the photoluminescence properties evaluated. The triplet state energies of the coordinated DBM ligands were determined using time-resolved phosphorescence spectra of analogous Gd 3+ complexes. The results show that the energies increase along with the number of coordinated nitrate anions replacing the DBM ligand in the complexes. The luminescence spectra and emission lifetime measurements revealed that the ligand-to-metal energy transfer efficiency follows the same tendency. Unlike the tris-DBM complexes, bis- and mono-DBM presented high luminescence, and may act as promising candidates for preparation of the emitting layer of light converting molecular devices (LCMDs). (author)

  11. Magnetocaloric effect and refrigeration cooling power in amorphous Gd7Ru3 alloys

    OpenAIRE

    Pramod Kumar; Rachana Kumar

    2015-01-01

    In this paper, we report the magnetic, heat capacity and magneto-caloric effect (MCE) of amorphous Gd7Ru3 compound. Both, temperature dependent magnetization and heat capacity data reveals that two transitions at 58 K and 34 K. MCE has been calculated in terms of isothermal entropy change (ΔSM) and adiabatic temperature change (ΔTad) using the heat capacity data in different fields. The maximum values of ΔSM and ΔTad are 21 Jmol−1K−1 and 5 K respectively, for field change of 50 kOe whereas re...

  12. Lifetime measurement in 144Gd

    International Nuclear Information System (INIS)

    Jensen, H.J.; Gast, W.; Georgiev, A.; Jaeger, H.M.; Lieder, R.M.; Utzelmann, S.; Gierlik, M.; Morek, T.; Przestrzelska, K.; Rzaca-Urban, T.; Dewald, A.; Kuehn, R.; Meier, C.; Ender, C.; Haertlein, T.

    1996-01-01

    The lifetime measurements of excited states in 144 Gd were carried out using the Koeln RDM-plunger together with the 2 x 3 CLUSTER detector setup in Heidelberg. The nucleus was populated in the 100 Mo( 48 Ti,4n) 144 Gd reaction at a beam energy of 205 MeV giving a recoil velocity of v/c = 2.6 %. Three and higher fold γ-ray coincidences were measured at 12 target-stopper distances ranged from 0 to 400 μm. Both the dipole and quadrupole bands in 144 Gd have been observed. The analysis is in progress

  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. Komatiites of the Onverwacht Group, S. Africa: REE geochemistry, Sm/Nd age and mantle evolution

    Science.gov (United States)

    Jahn, Bor-Ming; Gruau, G.; Glikson, A. Y.

    1982-08-01

    Komatiites of the Tjakastad Subgroup of the Onverwacht Group (S. Africa) were dated by the Sm/Nd method. A whole-rock isochron yields an age of 3.56±0.24 (2 σ) AE, with initial 143Nd/144Nd ratio of 0.50818±23 (2 σ), corresponding to ɛ Nd( T)= + 1.9±4.5. This age is interpreted as the time of initial Onverwacht volcanism. This result agrees with earlier Sm/Nd data of Hamilton et al. (1979) and is consistent with the Rb-Sr result of Jahn and Shih (1974). Komatiites may be divided into 3 groups based on the typology of heavy REE distributions (Jahn and Gruau 1981). According to this scheme, the Onverwacht komatiites of the present study belong to two groups: the predominant Group II rocks showing (Gd/Yb)N≃1.4, CaO/Al2O3 = 1.33, Al2O3/TiO2≃10.6; and the subordinate Group III rocks with (Gd/Yb)Nconnotation of the chemical parameters, such as CaO/Al2O3, (Gd/Yb)N or Al2O3/TiO2 ratio has not been firmly established. The characteristic “high” CaO/Al2O3 or (Gd/Yb)N ratios in many Onverwacht Group rocks can also be explained as a result of local short-term mantle heterogeneity.

  15. Fabrication, magnetostriction properties and applications of Tb-Dy-Fe alloys: a review

    Directory of Open Access Journals (Sweden)

    Nai-juan Wang

    2016-03-01

    Full Text Available As an excellent giant-magnetostrictive material, Tb-Dy-Fe alloys (based on Tb0.27-0.30Dy0.73-0.70Fe1.9-2 Laves compound can be applied in many engineering fields, such as sonar transducer systems, sensors, and micro-actuators. However, the cost of the rare earth elements Tb and Dy is too high to be widely applied for the materials. Nowadays, there are two different ways to substitute for these alloying elements. One is to partially replace Tb or Dy by cheaper rare earth elements, such as Pr, Nd, Sm and Ho; and the other is to use non-rare earth elements, such as Co, Al, Mn, Si, Ce, B, Be and C, to substitute Fe to form single MgCu2-type Laves phase and a certain amount of Re-rich phase, which can reduce the brittleness and improve the corrosion resistance of the alloy. This paper systemically introduces the development, the fabrication methods and the corresponding preferred growth directions of Tb-Dy-Fe alloys. In addition, the effects of alloying elements and heat treatment on magnetostrictive and mechanical properties of Tb-Dy-Fe alloys are also reviewed, respectively. Finally, some possible applications of Tb-Dy-Fe alloys are presented.

  16. Lanthanide-doped NaGdF4 core-shell nanoparticles for non-contact self-referencing temperature sensors.

    Science.gov (United States)

    Zheng, Shuhong; Chen, Weibo; Tan, Dezhi; Zhou, Jiajia; Guo, Qiangbing; Jiang, Wei; Xu, Cheng; Liu, Xiaofeng; Qiu, Jianrong

    2014-06-07

    We report that non-contact self-referencing temperature sensors can be realized with the use of core-shell nanostructures. These lanthanide-based nanothermometers (NaGdF4:Yb(3+)/Tm(3+)@Tb(3+)/Eu(3+)) exhibit higher sensitivity in a wide range from 125 to 300 K based on two emissions of Tb(3+) at 545 nm and Eu(3+) at 615 nm under near-infrared laser excitation.

  17. X-ray excited photoluminescence near the giant resonance in solid-solution Gd1-xTbxOCl nanocrystals and their retention upon solvothermal topotactic transformation to Gd1-xTbxF3

    Science.gov (United States)

    Waetzig, Gregory R.; Horrocks, Gregory A.; Jude, Joshua W.; Zuin, Lucia; Banerjee, Sarbajit

    2015-12-01

    Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb3+ centers upon excitation in proximity to the giant resonance of the host Gd3+ ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism from multiple exciton generation to single thermal exciton formation and Auger decay processes. The solid-solution Gd1-xTbxOCl nanocrystals are further topotactically transformed with retention of a nine-coordinated cation environment to solid-solution Gd1-xTbxF3 nanocrystals upon solvothermal treatment with XeF2. The metastable hexagonal phase of GdF3 can be stabilized at room temperature through this topotactic approach and is transformed subsequently to the orthorhombic phase. The fluoride nanocrystals indicate an analogous but blue-shifted modulation of the X-ray excited optical luminescence of the Tb3+ centers upon X-ray excitation near the giant resonance of the host Gd3+ ions.Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb3+ centers upon excitation in proximity to the giant resonance of the host Gd3+ ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism

  18. Combustion synthesis of micron-sized Sm2Co17 particles via mechanochemical processing

    International Nuclear Information System (INIS)

    Liu, W.; McCormick, P.G.

    1998-01-01

    Full text: The spontaneous formation of Sm 2 Co 17 micron-sized particles via a mechanically induced combustion reaction has been investigated. Sm 2 Co 17 alloy particles of 0.1--2 μm in size embedded in a CaO matrix formed directly via a combustion reaction induced by milling the powder mixture of Sm 2 O 3 , CoO, CaO and Ca over a critical time. The micron-sized Sm 2 Co 17 particles were found to have the TbCu 7 -type structure and characterized by a coercivity value of 7.8 kOe while embedded in the CaO matrix. The effect of subsequent heat treatment on the structure and magnetic properties of as-milled samples was also investigated. Removal of the CaO by a carefully controlled washing process yielded micron-sized Sm 2 Co 17 particles without significant oxidation of the particles. These fine Sm 2 Co 17 particles can be used to produce anisotropic bulk or bonded magnets

  19. Crystallographic and 119Sn and 155Gd Moessbauer analyses of Gd5Ge2(Si1-xSnx)2 (x = 0.23 and x = 0.40)

    International Nuclear Information System (INIS)

    Campoy, J. C. P.; Santos, A. O. dos; Cardoso, L. P.; Paesano, A.; Raposo, M. T.; Fabris, J. D.

    2010-01-01

    We report the structural characterization of Gd 5 Ge 2 (Si 1-x Sn x ) 2 (x = 0.23 and x = 0.40) compounds by means of 100 and 298 K-X-ray diffractometry (XRD) and 4 K- 155 Gd and 298 K- 119 Sn Moessbauer spectroscopy. These compounds order ferromagnetically at 218.4 and 172.7 K, respectively. At ∼100 K, it was identified the Gd 5 Si 4 -orthorhombic phase (type I) for both samples. At ∼298 K, it was identified a Gd 5 Si 2 Ge 2 -monoclinic phase, for x = 0.23 and a Sm 5 Sn 4 -orthorhombic phase (type II), for x 0.40. The Rietveld analysis of XRD data suggests a first order magneto-structural transition at Curie temperature for both compositions. Moessbauer results are well consistent with the proposed crystallographic models for these systems.

  20. Medicinal plants used to treat TB in Ghana.

    Science.gov (United States)

    Nguta, Joseph Mwanzia; Appiah-Opong, Regina; Nyarko, Alexander K; Yeboah-Manu, Dorothy; Addo, Phyllis G A

    2015-06-01

    The current study was designed to document medicinal plant species that are traditionally used to treat tuberculosis (TB) by Ghanaian communities. The medicinal plants used against TB or its signs and symptoms were selected using library and online published data searches. A guided questionnaire interview was also conducted with a botanist involved in plant collection at the Centre for Scientific Research into Plant Medicine (CSRPM) at Mampong. Data obtained were entered in Excel and summarized into means and frequencies using SPSS 12.0.1 for windows, and expressed as tables and bar graphs. A total of 15 medicinal plant species distributed between 13 genera and 13 families were documented. The following medicinal plant species were found to be used against TB in Greater Accra and Eastern parts of Ghana: Azadirachta indica A. Juss. Stem bark (Meliaceae), Hygrophila auriculata Heine, whole plant (Acanthaceae), Chenopodium ambrosioides L. leaves (Amaranthaceae), Coix lacryma-jobi L. glumes (Poaceae), Solanum torvum Sw. unripe fruits (Solanaceae), Solanum torvum Sw. leaves (Solanaceae), Bidens pilosa L. whole plant (Asteraceae), Phyllanthus fraternus G.L. Webster leaves (Phyllanthaceae), Dissotis rotundifolia (Sm.) Triana, leaves (Melastomataceae), Cymbopogon giganteus Chiov. Leaves (Poaceae), Cyperus articulatus L. roots (Cyperaceae), Allium sativum L. bulb (Amaryllidaceae), Zingiber officinale Roscoe, rhizomes (Zingiberaceae), Allium cepa L. bulbs (Amaryllidaceae), Allium cepa L. leaves (Amaryllidaceae), Aloe vera var. barbadensis aqueous extract from leaves (Xanthorrhoeaceae), Aloe vera var. barbadensis organic extract from leaves (Xanthorrhoeaceae), Cocos nucifera Linn, water (Arecaceae) and Cocos nucifera Linn. Husk (Arecaceae). The collected plant species could be a source of a new class of drugs against TB. Bioactivity guided fractionation is recommended to identify lead compounds for antimycobacterial activity. The current paper documents for the first time

  1. The Gd14Ag51 structure type and its relation to some complex amalgam structures

    International Nuclear Information System (INIS)

    Tambornino, Frank; Sappl, Jonathan; Hoch, Constantin

    2015-01-01

    Highlights: • The Gd 14 Ag 51 structure type has been revisited on the basis of single crystal diffraction data. • Symmetry analysis from electron density and TEM shows the space group P6/m to be true. • Gd 14 Ag 51 shows good metallic behaviour. • Structure relations to alkali, alkaline-earth and rare-earth metal amalgams can be established. • Complexity values for the RE 14 Ag 51 structure family were calculated. - Abstract: A plethora of binary and ternary intermetallic compounds has been assigned to the Gd 14 Ag 51 structure type, crystallising in the hexagonal system (space group P6/m, a = 1264.30(18) pm, c = 933.58(11) pm for Gd 14 Ag 51 ). Starting in the late 1960s, much work has been invested in the structural elucidation of these crystal structures. However, reliable single crystal data are scarce, and most structure type assignments have been performed merely on the basis of powder data. We have redetermined four representatives of the binary RE 14 Ag 51 structure type (RE = Y, Ce, Gd, Tb) with modern high-precision single crystal X-ray methods. The assignment of the Gd 14 Ag 51 structure type to space group P6/m was additionally verified by careful analysis of high resolution transmission electron micrographs. We emphasise the close relation of the Gd 14 Ag 51 structure type to the structures of some recently described amalgams of similar composition focussing on disorder phenomena and structural complexity. Furthermore, we provide detailed information on synthesis as well as electrical and magnetic properties for Gd 14 Ag 51 , the parent compound of this structure family

  2. 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

  3. Standard Missile-6 (SM-6)

    Science.gov (United States)

    2016-12-01

    attack or Anti-Ship Cruise Missiles in flight. The SM-6 ERAM program is an evolutionary, capabilities based acquisition program that will use spiral ...Prior SAR Total O&S Estimates - Dec 2014 SAR 460.3 Programmatic/Planning Factors 0.0 Cost Estimating Methodology 0.0 Cost Data Update 0.0 Labor Rate

  4. Growth of multiferroic Gd1-xYxMnO3 single crystals by optical floating zone technique

    International Nuclear Information System (INIS)

    Sarguna, R.M.; Ganesamoorthy, S.; Sridharan, V.; Subramanian, N.

    2014-01-01

    Rare earth manganites RMnO 3 with distorted perovskite structure are excellent multiferroic materials. The discovery of magnetic spin driven ferroelectricity in orthorhombic manganites (TbMnO 3 ) has sparked a surge in research into understanding the fundamental mechanism of multiferroic behavior. These systems fall under the category of type-2 multiferroics, the change of spatially modulated magnetic moment from sinusoidal to cycloidal gives rise to electric polarization. The magnetic structure depends upon the Mn-O-Mn bond angle. GdMnO 3 shows multiferroic properties only in the presence of applied magnetic field. When a magnetic field is applied along the b-axis, GdMnO 3 enters a ferroelectric state with an electric polarisation along the c-axis. By altering the Mn-O-Mn angle it is expected that GdMnO 3 will show multiferroic property even in the absence of magnetic field like TbMnO 3 . To alter the Mn-O-Mn bond angle GdMnO 3 was substituted with Y having lower ionic radius at Gd site. The effect of Y doping at the rare-earth site in GdMnO 3 investigated on polycrystalline samples of Gd 1-x Y x MnO 3 demonstrated a magneto-electric coupling in x=0.1-0.4. Single crystals are expected to give much amplified signal in respect of ferroelectric and magnetic properties. In this work we have grown Y substituted Gd 1-x Y x MnO 3 (x = 0.2, 0.3 and 0.4) by optical floating zone technique under different gas atmosphere. Growth rate of 1-2 mm/h yielded crack free crystals. Quality of the crystals was checked using Laue diffraction. Effect of growth rate and atmosphere pressure will be presented in this talk. (author)

  5. Detectemos la TB. Tratemos la TB. Trabajemos juntos para eliminar la TB. (Find TB. Treat TB. Working together to eliminate TB.)

    Centers for Disease Control (CDC) Podcasts

    2014-02-26

    Este podcast trata sobre el Día Mundial de la Tuberculosis y el tema de los CDC para el año 2014.  Created: 2/26/2014 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 2/26/2014.

  6. Investigation of BaMoO4-Ln2(MoO4)3 systems (Ln = Nd, Sm, Yb)

    International Nuclear Information System (INIS)

    Vakulyuk, V.V.; Evdokimov, A.A.; Khomchenko, G.P.

    1982-01-01

    Using the methods of X-ray phase and differential-thermal analyses phase ratios in the systems BaMoO 4 -Ln 2 (MoO 4 ) 3 (Ln=Nd, Sm, Yb); BaNd 2 (MoO 4 ) 4 -MaGd 2 (MoO 4 ) are studied. Unit cell parameters and the character of melting of the compounds BaLn 2 (MoO 4 ) 4 are specified. Effect of growth conditions on laminated nature of BaGd 2 (MoO 4 ) 4 monocrystals is studied

  7. 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)

  8. Småhuse: Indretning og funktion

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Sigbrand, Lone; Frandsen, Anne Kathrine

    Denne anvisning omhandler generelle krav og anbefalinger til indretning og funktion af nybyggede småhuse i henhold til bestemmelserne i Bygningsreglement 2010 (BR10). Småhuse - Indretning og funktionSmåhuse omfatter fritliggende og sammenbyggede enfamiliehuse med lodret lejlighedsskel i indtil...

  9. 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.

  10. Luminescence studies of Sm(III) and Cm(III) complexes in NaSCN/DHDECMP extraction systems

    CERN Document Server

    Chung, D Y; Kimura, T

    1999-01-01

    Laser-induced fluorescence (LIF) studies of Sm(III) and Cm(III) complexes in the NaSCN/DHDECMP solvent extraction system were carried out. Luminescence lifetimes were measured to determine the number of water molecules coordinated to Sm(III), Tb(III), Dy(III), and Cm(III) in the sodium thiocyanate solution and in the DHDECMP phase. The hydration number of Sm(III), Tb(III), Dy(III), and Cm(III) in the sodium thiocyanate solution decreased linearly with increasing sodium thiocyanate concentration. The hydration numbers of Sm(III), Dy(III), and Cm(III) in the DHDECMP phase decreased with increasing sodium thiocyanate concentration. The water molecules in the inner coordination sphere of Sm(III) and Dy(III) extracted into the DHDECMP were not completely removed at low sodium thiocyanate concentration but decreased with increasing sodium thiocyanate concentration. However, in the case of Cm(III) extracted into the DHDECMP phase from the sodium thiocyanate solution, there was no water in the inner coordination sphe...

  11. Ion chromatography separation of lanthanides at trace concentrations from Gd Matrix and quantification by ICP-MS

    International Nuclear Information System (INIS)

    Raut, V.V.; Jeyakumar, S.; Nagar, B.K.; Deb, S.B.; Saxena, M.K.; Tomar, B.S.

    2014-01-01

    Gadolinium compounds are mainly used as burnable poison. The presence of certain impurities is undesirable in the nuclear grade Gd compounds. Gd 2 O 3 , a most common raw material used for the preparation of nuclear grade Gd compounds. Analysis of rare earth impurities in Gd-matrices is one of the important exercises carried out to ensure the purity of Gd 2 O 3 . Determination of lanthanides at trace concentrations in lanthanide (Gd) matrix is complicated and difficult to realize. This is because the selective separation of REE's in one of the lanthanide elements is a challenging task. The present study was carried out to explore the feasibility of separating trace level lanthanides from Gd matrix by ion interaction chromatography (IIC) and to develop an analytical methodology for the determination of lanthanides by inductively coupled plasma mass spectrometry (ICP-MS). In the present investigation, the reversed phase column was dynamically modified into sulphonic acid functionalized surface by using 0.025 M n-Octane sulphonic acid (OSA). With α-HIBA eluent system, the elution order follows as Lu to La. The separations are employed with gradient elution mode. Since the sample has large excess of Gd, elution profiles with concentration gradient of HIBA were attempted. Separated fractions of Light lanthanides (LLn) and Heavy lanthanides (HLn) were collected and analyzed by ICP-MS. During MS analysis, it was observed that due to high concentration of salt (Na salt of OSA) present in the collected fractions caused difficulty in ICP-MS . Hence the experiments were carried out using another ion interacting reagent viz. 0.03 M camphor-10-sulphonic acid (CSA). Initial concentration of HIBA was kept at 0.025 M up to 15 min for the elution of HLns i.e. from Lu to Tb and it was then increased to 0.05 M to 0.3 M in 30 min. After elution of Tb, outlet of the column was switched to drain for 7 min to separate bulk Gd fraction. From 22 to 35 min effluent fraction containing Eu

  12. Applied strain dependence of critical current and internal lattice strain for BaHfO_3-doped GdBa_2Cu_3O_y coated conductors

    International Nuclear Information System (INIS)

    Usami, Takashi; Yoshida, Yutaka; Ichino, Yusuke; Sugano, Michinaka; Machiya, Shutaro; Ibi, Akira; Izumi, Teruo

    2016-01-01

    The strain effect of REBa_2Cu_3O_y (REBCO: RE = Y, Gd, Sm)-coated conductors (CCs) on critical current (I_c) is one of the most fundamental factors for superconducting coil applications. In this study, we aim to clarify the effect of artificial pinning center shapes on the strain effect in BHO-doped GdBCO CCs. To achieve this, we fabricated a Pure-GdBCO CC, a BHO nanorod-doped GdBCO CC and a multilayered-GdBCO (ML-GdBCO) CC, and carried out bending tests. As the result, the strain dependence of I_c for each CC showed an upward convex and the peak strain of the BHO-doped GdBCO CC shifts towards the compressive strain independent of the BHO shapes. In addition, the strain sensitivity of I_c in the GdBCO CCs including BHO becomes smaller. To clarify the difference between the strain sensitivity of I_c and the peak strain among the CCs, we evaluated the residual strain and the slopes of the internal lattice strains against the applied tensile strain (β). From this measurement, the residual strains for the Pure-GdBCO CC and the ML-GdBCO CC were almost the same. In addition, there was no change in the β value between the Pure-GdBCO and ML-GdBCO CCs. These results suggest that the changes in peak strain and strain sensitivity were not related to the internal lattice strain. (author)

  13. Litigation as TB Rights Advocacy

    Science.gov (United States)

    2016-01-01

    Abstract One thousand people die every day in India as a result of TB, a preventable and treatable disease, even though the Constitution of India, government schemes, and international law guarantee available, accessible, acceptable, quality health care. Failure to address the spread of TB and to provide quality treatment to all affected populations constitutes a public health and human rights emergency that demands action and accountability. As part of a broader strategy, health activists in India employ Public Interest Litigation (PIL) to hold the state accountable for rights violations and to demand new legislation, standards for patient care, accountability for under-spending, improvements in services at individual facilities, and access to government entitlements in marginalized communities. Taking inspiration from right to health PIL cases (PILs), lawyers in a New Delhi-based rights organization used desk research, fact-findings, and the Right To Information Act to build a TB PIL for the Delhi High Court, Sanjai Sharma v. NCT of Delhi and Others (2015). The case argues that inadequate implementation of government TB schemes violates the Constitutional rights to life, health, food, and equality. Although PILs face substantial challenges, this paper concludes that litigation can be a crucial advocacy and accountability tool for people living with TB and their allies. PMID:27781000

  14. Temperature effects on separation of Gd3+ from Gd-DTPA-folate using nanofiltration method

    Science.gov (United States)

    Rahayu, I.; Indraneli, R. P.; Yuliyati, Y. B.; Anggraeni, A.; Soedjanaatmadja, U. M. S.; Bahti, H. H.

    2018-05-01

    MRI is one of the best techniques in medical diagnostics. Contrast agents are used to improve the visual of organs that are difficult to distinguish through MRI. Gd-DTPA-folate is one of the specific contrast agents against cancer diagnosis, because it has a high affinity to folate receptors. In the complexing Gd-DTPA-folate, does not rule out the complexity step runs imperfectly, so there is still Gd3+ in the Gd-DTPA-folate complex. The separation of Gd3+ from the Gd-DTPA-folate complex is important to eliminate toxic effects on the contrast agent. This study aims to determine the effect of temperature on the separation of Gd-DTPA-folate from Gd3+ with nanofiltration. The method are preparation Gd-DTPA-folate from GdCl3.6H2O and DTPA-folate by reflux method, then separated Gd-DTPA-folate complex from Gd3+ with nanofiltration at variation temperature (40, 41, 42, 43, 44oC ). Then, the values of flux and rejection coefficients were analyzed. The results showed that the optimum temperature for the separation of Gd3+ from Gd-DTPA-folate was achieved at 42.6°C with the rejection coefficient of 24% and the permeate flux of 403 L.m-2.h-1.

  15. Biomarkers of latent TB infection

    DEFF Research Database (Denmark)

    Ruhwald, Morten; Ravn, Pernille

    2009-01-01

    For the last 100 years, the tuberculin skin test (TST) has been the only diagnostic tool available for latent TB infection (LTBI) and no biomarker per se is available to diagnose the presence of LTBI. With the introduction of M. tuberculosis-specific IFN-gamma release assays (IGRAs), a new area...... of in vitro immunodiagnostic tests for LTBI based on biomarker readout has become a reality. In this review, we discuss existing evidence on the clinical usefulness of IGRAs and the indefinite number of potential new biomarkers that can be used to improve diagnosis of latent TB infection. We also present...... early data suggesting that the monocyte-derived chemokine inducible protein-10 may be useful as a novel biomarker for the immunodiagnosis of latent TB infection....

  16. 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.

  17. TB in Children in the United States

    Science.gov (United States)

    ... Regimen for Latent TB Infection-Patient Education Brochure Posters Mantoux Tuberculin Skin Test Wall Chart World TB ... site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel file Audio/Video file Apple ...

  18. 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

  19. Extensively Drug-Resistant TB

    Centers for Disease Control (CDC) Podcasts

    2016-12-16

    Dr. Charlotte Kvasnovsky, a surgery resident and Ph.D. candidate in biostatistics, discusses various types of drug resistance in TB patients in South Africa.  Created: 12/16/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 12/16/2016.

  20. TB in Wild Asian Elephants

    Centers for Disease Control (CDC) Podcasts

    2017-05-10

    Dr. Susan Mikota, co-founder of Elephant Care International, discusses TB in wild Asian elephants.  Created: 5/10/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 5/10/2017.

  1. Community Involvement in TB Research

    NARCIS (Netherlands)

    M. van der Werf (Marloes); S.G. Heumann (Silke); E.M.H. Mitchell

    2011-01-01

    textabstractWhile communities at risk have been both drivers and partners in HIV research, their important role in TB research is yet to be fully realized. Involvement of communities in tuberculosis care and prevention is currently on the international agenda. This creates opportunities and

  2. GD 358 - the demise of rotational splitting?

    International Nuclear Information System (INIS)

    Hill, J.A.

    1987-01-01

    Observations of GD 358 were obtained at the McDonald Observatory in 1982 and 1985 in order to determine its periods, stability, and rates of period change. The period structure could not be resolved, and the results indicate that GD 358 does not fit the rotational splitting model. It is suggested that if the changes in the amplitude spectra of GD 358 are due to beating of stable modes, then the number of modes must be large. 7 references

  3. Measurement of 160Tb and 161Tb in nuclear forensics samples

    International Nuclear Information System (INIS)

    Jiang, J.; Davies, A.V.; Britton, R.E.

    2017-01-01

    160 Tb and 161 Tb are important radionuclides to measure when analysing a Nuclear Forensics sample. An analytical method for the measurement of both 160 Tb and 161 Tb was developed in this study. Terbium was separated and purified using exchange resin and TrisKem LN Resin. The purified fraction containing 160 Tb and 161 Tb was measured by gamma spectrometry and liquid scintillation counting. The counting efficiencies of 160 Tb and 161 Tb were determined using the CIEMAT/NIST efficiency tracing method. The LSC count rate ratio, R160 Tb /R161 Tb , on the reference date was determined by sequential counting and calculated using a custom script based on their half-lives. (author)

  4. 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 ...

  5. 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)

  6. Prospective use of soluble urokinase plasminogen activator receptor to screen TB co-infected with HIV patient among TB patient

    Directory of Open Access Journals (Sweden)

    Tri Yudani Mardining Raras

    2017-10-01

    Conclusion: Plasma suPAR level of TB patients co-infected with HIV showed significantly difference from that of TB-AFB(+ patients suggested its potential to screen the TB/HIV among pulmonary TB-AFB(+ patients.

  7. Heightened vulnerability to MDR-TB epidemics after controlling drug-susceptible TB.

    Directory of Open Access Journals (Sweden)

    Jason D Bishai

    2010-09-01

    Full Text Available Prior infection with one strain TB has been linked with diminished likelihood of re-infection by a new strain. This paper attempts to determine the role of declining prevalence of drug-susceptible TB in enabling future epidemics of MDR-TB.A computer simulation of MDR-TB epidemics was developed using an agent-based model platform programmed in NetLogo (See http://mdr.tbtools.org/. Eighty-one scenarios were created, varying levels of treatment quality, diagnostic accuracy, microbial fitness cost, and the degree of immunogenicity elicited by drug-susceptible TB. Outcome measures were the number of independent MDR-TB cases per trial and the proportion of trials resulting in MDR-TB epidemics for a 500 year period after drug therapy for TB is introduced.MDR-TB epidemics propagated more extensively after TB prevalence had fallen. At a case detection rate of 75%, improving therapeutic compliance from 50% to 75% can reduce the probability of an epidemic from 45% to 15%. Paradoxically, improving the case-detection rate from 50% to 75% when compliance with DOT is constant at 75% increases the probability of MDR-TB epidemics from 3% to 45%.The ability of MDR-TB to spread depends on the prevalence of drug-susceptible TB. Immunologic protection conferred by exposure to drug-susceptible TB can be a crucial factor that prevents MDR-TB epidemics when TB treatment is poor. Any single population that successfully reduces its burden of drug-susceptible TB will have reduced herd immunity to externally or internally introduced strains of MDR-TB and can experience heightened vulnerability to an epidemic. Since countries with good TB control may be more vulnerable, their self interest dictates greater promotion of case detection and DOTS implementation in countries with poor control to control their risk of MDR-TB.

  8. Identification of 162Gd and a new type of identical bands

    International Nuclear Information System (INIS)

    Jones, E. F.; Gore, P. M.; Hamilton, J. H.; Ramayya, A. V.; Dodder, R. S.; Beyer, C. J.; Hwang, J. K.; Zhang, X. Q.; Kormicki, J.; Zhu, S. J.; Lima, A. P. de; Cole, J. D.; Aryaeinejad, R.; Ma, W. C.; Ter-Akopian, G. M.; Daniel, A. V.; Oganessian, Yu. Ts.; Rasmussen, J. O.; Asztalos, S. J.; Lee, I. Y.

    1998-01-01

    From γ-γ-γ coincidence measurements in spontaneous fission of 252 Cf, level energies were established to spins 14 + to 20 + in many neutron-rich nuclei. New isotope 162 Gd was identified. Yrast bands of 152,154,156 Nd, 156,158,160 Sm, and 160,162 Gd exhibit near-identical transition energies and moments of inertia (MOI) shifted by the same constant amounts for every spin state from 2 + to 12 + or 14 + for nuclei differing by 2n, 4n, 2p, 4p, α, α+2p, and α+2n. These shifted identical bands (SIB) are a new phenomenon. Analysis of all known even-even proton- to neutron-rich nuclei from Ba(Z=56) to Os(Z=76) reveal no SIB for proton-rich nuclei and few cases of SIB for the most neutron-rich pairs around N=98-102 separated by 2n and 2p

  9. 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

  10. The Gd{sub 14}Ag{sub 51} structure type and its relation to some complex amalgam structures

    Energy Technology Data Exchange (ETDEWEB)

    Tambornino, Frank; Sappl, Jonathan; Hoch, Constantin, E-mail: constantin.hoch@cup.uni-muenchen.de

    2015-01-05

    Highlights: • The Gd{sub 14}Ag{sub 51} structure type has been revisited on the basis of single crystal diffraction data. • Symmetry analysis from electron density and TEM shows the space group P6/m to be true. • Gd{sub 14}Ag{sub 51} shows good metallic behaviour. • Structure relations to alkali, alkaline-earth and rare-earth metal amalgams can be established. • Complexity values for the RE{sub 14}Ag{sub 51} structure family were calculated. - Abstract: A plethora of binary and ternary intermetallic compounds has been assigned to the Gd{sub 14}Ag{sub 51} structure type, crystallising in the hexagonal system (space group P6/m, a = 1264.30(18) pm, c = 933.58(11) pm for Gd{sub 14}Ag{sub 51}). Starting in the late 1960s, much work has been invested in the structural elucidation of these crystal structures. However, reliable single crystal data are scarce, and most structure type assignments have been performed merely on the basis of powder data. We have redetermined four representatives of the binary RE{sub 14}Ag{sub 51} structure type (RE = Y, Ce, Gd, Tb) with modern high-precision single crystal X-ray methods. The assignment of the Gd{sub 14}Ag{sub 51} structure type to space group P6/m was additionally verified by careful analysis of high resolution transmission electron micrographs. We emphasise the close relation of the Gd{sub 14}Ag{sub 51} structure type to the structures of some recently described amalgams of similar composition focussing on disorder phenomena and structural complexity. Furthermore, we provide detailed information on synthesis as well as electrical and magnetic properties for Gd{sub 14}Ag{sub 51}, the parent compound of this structure family.

  11. Ferromagnetic and paramagnetic magnetization of implanted GaN:Ho,Tb,Sm,Tm films

    Czech Academy of Sciences Publication Activity Database

    Maryško, Miroslav; Hejtmánek, Jiří; Laguta, Valentyn; Sofer, Z.; Sedmidubský, D.; Šimek, P.; Veselý, M.; Mikulics, M.; Buchal, C.; Macková, Anna; Malinský, Petr; Wilhelm, R. A.

    2015-01-01

    Roč. 117, č. 17 (2015), "17B907-1"-"17B907-4" ISSN 0021-8979 R&D Projects: GA ČR GA13-20507S; GA ČR(CZ) GBP108/12/G108; GA MŠk LM2011019 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : magnetic field, * ferromagnetic and paramagnetic magnetization Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.101, year: 2015

  12. checkCIF/PLATON report Datablock: Sm

    Indian Academy of Sciences (India)

    Moiety formula C59 H45 N2 O6 Sm. Sm (C14 H12 N2) ... 4.0 Ratio. PLAT234_ALERT_4_C Large Hirshfeld Difference O4 -- C24 .. 0.16 Ang. ... outliers and unusual parameters, but every test has its limitations and alerts that are not important.

  13. Influence of nitrogenation on structure development and magnetic properties of mechanically alloyed and annealed Sm-Fe powders

    Energy Technology Data Exchange (ETDEWEB)

    Teresiak, A.; Kubis, M.; Mattern, N.; Wolf, M.; Gruner, W.; Mueller, K.-H. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany)

    1999-11-15

    Sm-Fe-N compounds were prepared by mechanical alloying, subsequent annealing and nitrogenation. For crystal structure investigations of the non-equilibrium phases Sm{sub 2}Fe{sub 17+y}N{sub x}, formed at various annealing temperatures T{sub A} for 1 h, X-ray diffraction with following Rietveld analysis was used. A volume expansion of 6.2% was observed after nitrogenation. As for the non-nitrided Sm-Fe alloys a modified TbCu{sub 7}-type structure (space group P6/mmm) and a modified Th{sub 2}Zn{sub 17}-type structure (space group R anti 3m) have been observed. However, for nitrogenated Sm-Fe samples the modified Th{sub 2}Zn{sub 17}-type structure forms already for annealing at T{sub A}=750 C prior to nitrogenation. For samples annealed, prior to nitrogenation, between T{sub A}=600 and 700 C the modified TbCu{sub 7}-type structure was found, in which the nitrogen occupies randomly the 3f position with an occupancy larger than 1/3. The partially ordered, modified Th{sub 2}Zn{sub 17}-type structure formed for 750 CSm(3a) positions. The degree of order of the Sm atoms and Fe-dumbbells increases with increasing T{sub A}. The nitrogen occupies the octahedral interstitial positions 9e in the latter cases. The nitrogen content is higher in the hexagonal phase than in the rhombohedral phase. Optimum magnetic properties were obtained for T{sub A}=750 C. Here we found a coercivity {mu}{sub 0J}H{sub c}=3.7 T and a good squareness of the demagnetization curve. (orig.)

  14. Influence of nitrogenation on structure development and magnetic properties of mechanically alloyed and annealed Sm-Fe powders

    International Nuclear Information System (INIS)

    Teresiak, A.; Kubis, M.; Mattern, N.; Wolf, M.; Gruner, W.; Mueller, K.-H.

    1999-01-01

    Sm-Fe-N compounds were prepared by mechanical alloying, subsequent annealing and nitrogenation. For crystal structure investigations of the non-equilibrium phases Sm 2 Fe 17+y N x , formed at various annealing temperatures T A for 1 h, X-ray diffraction with following Rietveld analysis was used. A volume expansion of 6.2% was observed after nitrogenation. As for the non-nitrided Sm-Fe alloys a modified TbCu 7 -type structure (space group P6/mmm) and a modified Th 2 Zn 17 -type structure (space group R anti 3m) have been observed. However, for nitrogenated Sm-Fe samples the modified Th 2 Zn 17 -type structure forms already for annealing at T A =750 C prior to nitrogenation. For samples annealed, prior to nitrogenation, between T A =600 and 700 C the modified TbCu 7 -type structure was found, in which the nitrogen occupies randomly the 3f position with an occupancy larger than 1/3. The partially ordered, modified Th 2 Zn 17 -type structure formed for 750 C A 2 Zn 17 -type structure by introducing additional Fe(6c) and Sm(3a) positions. The degree of order of the Sm atoms and Fe-dumbbells increases with increasing T A . The nitrogen occupies the octahedral interstitial positions 9e in the latter cases. The nitrogen content is higher in the hexagonal phase than in the rhombohedral phase. Optimum magnetic properties were obtained for T A =750 C. Here we found a coercivity μ 0J H c =3.7 T and a good squareness of the demagnetization curve. (orig.)

  15. Evaluation of Radioisotope Production Process of 153Sm and 153Sm-EDTMP Radiopharmaceuticals

    International Nuclear Information System (INIS)

    Kadarisman; Sri Hastini; Yayan Tahyan; Abidin; Dadang Hafid; Enny Lestari

    2007-01-01

    Experiments on the process of 153 Sm radioisotope and labeling of 153 Sm-EDTMP radiopharmaceuticals were carried out. This experiments included preparation of Sm 2 O 3 target, dissolution of post irradiation, determination of radioactivity concentration of 153 Sm radioisotope, radionuclide purity, EDTMP labeling, determination of radiochemical purity and pH. In these experiments the total radioactivity 153 Sm product is round about 2845.83 mCi to 36963.31 mCi, or with the radioactivity concentration between 474 mCi/ml to 6160.55 mCi/ml in the SmCl 3 solution form, each its volume is 6.0 ml, and the samarium content is 5.76 mg/ml, and the radionuclide purity of 153 Sm is 100 %. All of the 153 Sm- EDTMP radiopharmaceuticals product are fulfilled requirements the radioactivity concentration, Sm content, radiochemical purity and pH. The radioactivity concentration of 153 Sm-EDTMP radiopharmaceuticals is 37.50 mCi/ml (minimum) to 283.50 mCi/ml (highest). The pH 7.5 were 8 products, and the rest are pH 8.5. Radiochemical purity of 153 Sm-EDTMP are round about 90.00 % to 99.44 %. (author)

  16. Distinguishing a SM-like MSSM Higgs boson from SM Higgs boson at muon collider

    International Nuclear Information System (INIS)

    Singhal, Jai Kumar; Singh, Sardar; Nagawat, Ashok K.

    2007-01-01

    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 tanβ and m A . 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 relative percentage deviation in cross-section. The observed deviations in cross-section for different choices of Higgs boson masses suggest that the measurements of the cross-section could possibly distinguish the SM-like MSSM Higgs boson from the SM Higgs boson. (author)

  17. TB control programmes: the challenges for Africa.

    Science.gov (United States)

    Harries, T

    1996-11-01

    Governmental neglect of tuberculosis (TB), inadequately managed and inaccurately designed TB control programs, population growth, and the HIV epidemic account for the resurgence of TB in sub-Saharan Africa. The World Health Organization and the International Union against TB and Lung Disease have developed a TB control strategy that aims to reduce mortality, morbidity, and transmission of TB. It aims for an 85% cure rate among detected new cases of smear-positive TB and a 70% rate of detecting existing smear-positive TB cases. The strategy involves the provision of short-course chemotherapy (SCC) to all identified smear-positive TB cases through directly observed treatment (DOTS). SCC treatment regimens for smear-positive pulmonary TB recommended for sub-Saharan African countries are: initial phase = daily administration over 2 months of streptomycin, rifampicin, isoniazid, and pyrazinamide; continuation phase = 3 doses over 4 months of isoniazid and rifampicin or daily administration of thiacetazone and isoniazid or of ethambutol and isoniazid. A TB control policy must be implemented to bring about effective TB control. The essential elements of this policy include political commitment, case detection through passive case-finding, SCC, a regular supply of essential drugs, and a monitoring and evaluation system. Political commitment involves establishing a National TB Control Program to be integrated into the existing health structure. Increased awareness of TB in the community and among health workers and a reference laboratory are needed to make case finding successful. A distribution and logistics system is needed to ensure uninterrupted intake of drugs throughout treatment. These regimens have been very successful and cost-effective but pose several disadvantages (e.g., heavy workload of recommended 3 sputum smear tests). A simplified approach involves 1 initial sputum smear for 6 months; 6-months, intermittent rifampicin-based therapy, 100% DOTS throughout

  18. Favored neutron excitations in superdeformed Gd-147

    NARCIS (Netherlands)

    Theisen, C; Khadiri, N; Vivien, JP; Ragnarsson, J; Beausang, CW; Beck, FA; Belier, G; Byrski, T; Curien, D; deFrance, G; Disdier, D; Duchene, G; Finck, C; Flibotte, S; Gall, B; Haas, B; Hanine, H; Herskind, B; Kharraja, B; Merdinger, JC; Nourreddine, A; Nyako, BM; Perez, GE; Prevost, D; Stezowski, O; Rauch, I; Rigollet, C; Savajols, H; SharpeySchafer, J; Twin, PJ; Wei, L; Zuber, K

    1996-01-01

    Four new superdeformed (SD) bands have been observed in Gd-147 using the EUROGAM II spectrometer. By comparison with (146,148,149),Gd SD bands, we use the effective alignment to assign excited band configurations, with the support of the Nilsson-Strutinsky cranking formalism. The effect of the

  19. Influence of annealing and nitrogenation on structure and magnetic properties of mechanically alloyed Sm-Fe powders

    International Nuclear Information System (INIS)

    Teresiak, A.; Kubis, M.; Mattern, N.; Wolf, M.; Mueller, K.-H.

    1998-01-01

    Sm-Fe-N compounds were prepared by mechanical alloying, subsequent annealing and nitrogenation. For crystal structure investigations of the non-equilibrium phases Sm 2 Fe 17+x and Sm 2 Fe 17+x N y , respectively, formed at the various annealing temperatures T A , XRD with following Rietveld analysis was used. For T A between 600 C and 750 C a modified hexagonal TbCu 7 structure (space group P6/mmm) was found in which the Fe(2c) site is replaced by the partially (1/3) and randomly occupied Fe(61) site. The approximated composition is SmFe 8.8-9.0 . The nitrogenated alloys crystallize in the same structure for 600 C A A ≤ 900 C a disordered modified Th 2 Zn 17 structure (space group R anti 3m) was found that is formed by introducing additional Fe (6c) and Sm(3a) positions. The degree of order of the Sm- and Fe-atoms in c-direction increases with increasing annealing temperature. The completely ordered stoichiometric Sm 2 Fe 17 structure could not be reached by annealing the ball milled elemental powders. The nitrided alloys already form this intermediate structure at T A = 750 C. The interstitial nitrogen occupies the 9e site. The estimated nitrogen content is higher in the hexagonal phases than in the rhombohedral phase. Optimum magnetic properties, in particular a coercitivity μ 01 H C = 3.7 T and a good squareness of the demagnetization curve, were obtained for T A = 750 C. Here we found a nitrogen content of y = 3 for Sm 2 Fe 17+x N y . (orig.)

  20. Physico-chemical characterization of terbium-161-chloride (161TbCl3) radioisotope from irradiated natural gadolinium oxide target

    International Nuclear Information System (INIS)

    Azmairit Aziz; Nana Suherman

    2015-01-01

    Currently cancer patients are increasing every year in Indonesia and become the third leading cause of death after heart disease and high blood pressure. Terbium-161 ( 161 Tb) is a low β- emitter (E β - = 0.155 MeV, T 1/2 = 6.9 d) and very similar to 177 Lu in terms of half-life, E β - energy and chemical properties.However, 161 Tb also ejects internal conversion electrons and Auger electrons which can provide a greater therapeutic effect than 177 Lu. Radioisotope of 161 Tb can be produced as a carrier-free for use in labeling of biomolecules as a targeted radiopharmaceutical for cancer therapy. 161 Tb was obtained through 160 Gd(n,γ) 161 Tb nuclear reaction by thermal neutron bombardment on 100 mg of natural gadolinium oxide target in RSG-G.A. Siwabessy at a thermal neutron flux of ~10 14 n.cm -2 .s -1 and followed by radiochemical separation of 161 Tb from Gd isotopes using extraction chromatography method. The physico-chemical characterization of 161 TbCl 3 solution was studied by determination of its radionuclide purity by means of a γ-rays spectrometry with HP-Ge detector coupled to a multichannel analyzer (MCA). Radiochemical purity was determined using paper chromatography and paper electrophoresis methods. The results showed that 161 TbCl 3 radioisotope has a pH of 2, radiochemical purity of 99.64 ± 0.34%, radionuclide purity of 99.69 ± 0.20%, specific activity and radioactive concentration at the end of irradiation (EOI) of 2.26 – 5.31 Ci/mg and 3.84 – 9.03 mCi/mL, respectively. 161 TbCl 3 solution stable for 3 weeks at room temperature with a radiochemical purity of 98.41 ± 0.42%. 161 TbCl 3 solution from irradiated natural gadolinium oxide target has the physico-chemical characteristic that meets the requirements for use as a precursor in preparation of radiopharmaceuticals. (author)

  1. Preparation and spectral analysis of a new Tb3+-doped CaO-MgO-SiO2 glass ceramics

    International Nuclear Information System (INIS)

    Cheng Jinshu; Tian Peijing; Zheng Weihong; Xie Jun; Chen Zhenxia

    2009-01-01

    Tb 3+ -doped CaO-MgO-SiO 2 glass ceramics have been prepared and characterized. The structure and optical properties of the glass ceramics were studied by XRD, SEM, Raman, and fluorescence spectra. The precipitated crystalline phase in the glass ceramics was columnar CaMgSi 2 O 6 . Raman spectra showed the introduction of rare earth nearly had no influence on the sample structure. Fluorescence measurements showed that Tb 3+ ions entered into the diopside crystalline phase and induced a much stronger emission in the glass ceramics than that in the corresponding glass. With increase of Tb 3+ content and the introduction of Gd 3+ , the fluorescence intensity of the luminescent glass ceramic increased

  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. Magnetic and magnetocaloric properties of partially disordered RFeAl (R = Gd, Tb) intermetallic

    Czech Academy of Sciences Publication Activity Database

    Kaštil, Jiří; Javorský, P.; Kamarád, Jiří; Diop, L.V.B.; Isnard, O.; Arnold, Zdeněk

    2014-01-01

    Roč. 54, Nov (2014), s. 15-19 ISSN 0966-9795 Institutional support: RVO:68378271 Keywords : magnetic properties * thermodynamic properties * energy systems Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.131, year: 2014

  5. Peculiarities of component interaction in {Gd, Er}-V-Sn Ternary systems at 870 K and crystal structure of RV6Sn6 stannides

    International Nuclear Information System (INIS)

    Romaka, L.; Stadnyk, Yu.; Romaka, V.V.; Demchenko, P.; Stadnyshyn, M.; Konyk, M.

    2011-01-01

    Highlights: → {Gd, Er}-V-Sn ternary systems at 870 K are characterized by formation of stannides with general compositions RV 6 Sn 6 . → Isostructural RV 6 Sn 6 compounds were also found with Y, Dy, Ho, Tm, and Lu. → The crystal structure of RV 6 Sn 6 compounds was determined by powder diffraction method. → Structural analysis showed that RV 6 Sn 6 compounds (R = Gd, Dy-Tm, Lu) are disordered; YV 6 Sn 6 is characterized by structure ordering. - Abstract: The phase equilibria in the Gd-V-Sn and Er-V-Sn ternary systems were studied at 870 K by means of X-ray and metallographic analyses in the whole concentration range. Both Gd-V-Sn and Er-V-Sn systems are characterized by formation of one ternary compound at investigated temperature, with stoichiometry RV 6 Sn 6 (SmMn 6 Sn 6 -type, space group P6/mmm, a = 0.55322(3) nm, c = 0.91949(7) nm for Gd, a = 0.55191(2) nm, c = 0.91869(8) nm for Er). Solubility of the third component in the binary compounds was not observed. Compounds with the SmMn 6 Sn 6 -type were also found with Dy, Ho, Tm, and Lu, while YV 6 Sn 6 compound crystallizes in HfFe 6 Ge 6 structure type. All investigated compounds are the first ternary stannides with rare earth elements and vanadium.

  6. 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

  7. Energy transfer processes in Tb(III)-dibenzoylmethanate complexes with phosphine oxide ligands

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, Francisco A.; Nascimento, Helenise A.; Pereira, Dariston K.S.; Teotonio, Ercules E.S.; Espinola, Jose Geraldo P.; Faustino, Wagner M., E-mail: teotonioees@quimica.ufpb.br [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Departamento de Quimica; Brito, Hermi F. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Quimica. Departamento de Quimica Fundamental; Felinto, Maria Claudia F.C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), SP (Brazil); Sa, Gilberto F. [Universidade Federal de Pernambuco (UFPE/CCEN), Recife, PE (Brazil). Centro de Ciencias Exatas e da Natureza. Departamento de Quimica Fundamental

    2013-04-15

    The Tb{sup 3+}-{beta}-diketonate complexes [Tb(DBM){sub 3}L], [Tb(DBM){sub 2}(NO{sub 3})L{sub 2}] and [Tb(DBM)(NO{sub 3}){sub 2} (HMPA){sub 2}] (DBM = dibenzoylmethanate; L: TPPO triphenylphosphine oxide or HMPA=hexamethylphosphine oxide) were prepared and characterized by elemental analysis (CHN), complexometric titration with EDTA and Fourier transform infrared (FTIR) spectroscopy, and the photoluminescence properties evaluated. The triplet state energies of the coordinated DBM ligands were determined using time-resolved phosphorescence spectra of analogous Gd{sup 3+} complexes. The results show that the energies increase along with the number of coordinated nitrate anions replacing the DBM ligand in the complexes. The luminescence spectra and emission lifetime measurements revealed that the ligand-to-metal energy transfer efficiency follows the same tendency. Unlike the tris-DBM complexes, bis- and mono-DBM presented high luminescence, and may act as promising candidates for preparation of the emitting layer of light converting molecular devices (LCMDs). (author)

  8. Luminescence Properties of Self-Aggregating TbIII-DOTA-Functionalized Calix[4]arenes

    Science.gov (United States)

    Mayer, Florian; Tiruvadi Krishnan, Sriram; Schühle, Daniel T.; Eliseeva, Svetlana V.; Petoud, Stéphane; Tóth, Éva; Djanashvili, Kristina

    2018-01-01

    Self-aggregating calix[4]arenes carrying four DOTA ligands on the upper rim for stable complexation of paramagnetic GdIII-ions have already been proposed as MRI probes. In this work, we investigate the luminescence properties of TbIII-DOTA-calix[4]arene-4OPr containing four propyl-groups and compare them with those of the analogue substituted with a phthalimide chromophore (TbIII-DOTA-calix[4]arene-3OPr-OPhth). We show that, given its four aromatic rings, the calix[4]arene core acts as an effective sensitizer of Tb-centered luminescence. Substituents on the lower rim can modulate the aggregation behavior, which in turn determines the luminescence properties of the compounds. In solid state, the quantum yield of the phthalimide derivative is almost three times as high as that of the propyl-functionalized analogue demonstrating a beneficial role of the chromophore on Tb-luminescence. In solution, however, the effect of the phthalimide group vanishes, which we attribute to the large distance between the chromophore and the lanthanide, situated on the opposite rims of the calix[4]arene. Both quantum yields and luminescence lifetimes show clear concentration dependence in solution, related to the strong impact of aggregation on the luminescence behaviour. We also evidence the variability in the values of the critical micelle concentration depending on the experimental technique. Such luminescent calix[4]arene platforms accommodating stable lanthanide complexes can be considered valuable building blocks for the design of dual MR/optical imaging probes.

  9. 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)

  10. 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)

  11. Site preference of metal atoms in Gd_5_-_xM_xTt_4 (M = Zr, Hf; Tt = Si, Ge)

    International Nuclear Information System (INIS)

    Yao, Jinlei; Mozharivskyj, Yurij

    2011-01-01

    Zirconium and hafnium were incorporated into the Gd_5Ge_4 and Gd_5Si_4 parent compounds in order to study the metal-site occupation in the M_5X_4 magnetocaloric phases (M = metals; X = p elements) family. The Gd_5_-_xZr_xGe_4 phases adopt the orthorhombic Sm_5Ge_4-type (space group Pnma) structure for x ≤ 1.49 and the tetragonal Zr_5Si_4-type (P4_12_12) structure for x ≥ 1.77. The Gd_5_-_xHf_xSi_4 compounds crystallize in the orthorhombic Gd_5Si_4-type (Pnma) structure for x ≤ 0.41 and the Zr_5Si_4-type structure for x ≥ 0.7. In both systems, single-crystal X-ray diffraction reveals that the Zr/Hf atoms preferentially occupy the slab-surface M2 and slab-center M3 sites, both of which have a significantly larger Zr/Hf population than the slab-surface M1 site. The metal-site preference, i.e. the coloring problem on the three metal sites, is discussed considering geometric and electronic effects of the local coordination environments. The analysis of the metal-site occupation in Gd_5_-_xZr_xGe_4 and Gd_5_-_xHf_xSi_4 as well as other metal-substituted M_5X_4 systems suggests that both geometric and electronic effects can be used to explain the metal-site occupation. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  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. Observation of dipole bands in 144Sm

    International Nuclear Information System (INIS)

    Raut, R.; Ganguly, S.; Kshetri, R.; Banerjee, P.; Bhattacharya, S.; Dasmahapatra, B.; Mukherjee, A.; Sahasarkar, M.; Goswami, A.; Basu, S.K.; Bhattacharjee, T.; Mukherjee, G.; Chakraborty, A.; Ghughre, S.S.; Krishichayan; Mukhopadhyay, S.; Gangopadhyay, G.; Singh, A.K.

    2007-01-01

    The nucleus 144 Sm (Z=62, N=82), with its proximity to the shell closure and possibilities of particles and holes occupying high j orbitals, following appropriate excitations, is a suitable system for observation of dipole (MR) bands

  14. Air stability and magnetic properties of GdN, TiN, and (Gd,Ti)N nanoparticles

    International Nuclear Information System (INIS)

    Si Pingzhan; Choi, C. J.; Tegus, O.; Brueck, E.; Geng, D. Y.; Zhang, Z. D.

    2008-01-01

    GdN, TiN, and (Gd,Ti)N nanoparticles were prepared by arc evaporating Gd, Ti, and Gd-Ti alloys in N 2 , respectively. Most of these nanoparticles show narrow size distribution with average diameter of 20 nm. Shell/core structure was observed in the (Gd,Ti)N nanoparticles, in which the shell was formed by surface reaction with air. (Gd,Ti)N nanoparticles are more stable than GdN nanoparticles in air due partially to the formation of the protective shell. The Curie temperature of GdN nanoparticles is lower than that of the bulk GdN. Both GdN and (Gd, Ti)N nanoparticles are difficult to reach magnetic saturation and show zero coercivity

  15. Favored neutron excitations in superdeformed 147Gd

    International Nuclear Information System (INIS)

    Theisen, C.; Khadiri, N.; Vivien, J.P.; Ragnarsson, I.; Beausang, C.W.; Beck, F.A.; Belier, G.; Byrski, T.; Curien, D.; de France, G.; Disdier, D.; Duchene, G.; Finck, C.; Flibotte, S.; Gall, B.; Haas, B.; Hanine, H.; Herskind, B.; Kharraja, B.; Merdinger, J.C.; Nourreddine, A.; Nyako, B.M.; Perez, G.E.; Prevost, D.; Stezowski, O.; Rauch, V.; Rigollet, C.; Savajols, H.; Sharpey-Schafer, J.; Twin, P.J.; Wei, L.; Zuber, K.

    1996-01-01

    Four new superdeformed (SD) bands have been observed in 147 Gd using the EUROGAM II spectrometer. By comparison with 146,148,149 Gd SD bands, we use the effective alignment to assign excited band configurations, with the support of the Nilsson-Strutinsky cranking formalism. The effect of the crossing of the [642]5/2 and [651]1/2 neutron orbitals lying just below the magic N=86 SD shell gap has been investigated for the 146,147,148 Gd bands. Evidence for the [411]1/2 orbital is also given. copyright 1996 The American Physical Society

  16. Why healthcare workers are sick of TB

    Directory of Open Access Journals (Sweden)

    Arne von Delft

    2015-03-01

    Full Text Available Dr Thato Mosidi never expected to be diagnosed with tuberculosis (TB, despite widely prevalent exposure and very limited infection control measures. The life-threatening diagnosis of primary extensively drug-resistant TB (XDR-TB came as an even greater shock. The inconvenient truth is that, rather than being protected, Dr Mosidi and thousands of her healthcare colleagues are at an increased risk of TB and especially drug-resistant TB. In this viewpoint paper we debunk the widely held false belief that healthcare workers are somehow immune to TB disease (TB-proof and explore some of the key factors contributing to the pervasive stigmatization and subsequent non-disclosure of occupational TB. Our front-line workers are some of the first to suffer the consequences of a progressively more resistant and fatal TB epidemic, and urgent interventions are needed to ensure the safety and continued availability of these precious healthcare resources. These include the rapid development and scale-up of improved diagnostic and treatment options, strengthened infection control measures, and focused interventions to tackle stigma and discrimination in all its forms. We call our colleagues to action to protect themselves and those they care for.

  17. Giant anisotropy of magnetocaloric effect in TbMnO3 single crystals

    Science.gov (United States)

    Jin, Jin-Ling; Zhang, Xiang-Qun; Li, Guo-Ke; Cheng, Zhao-Hua; Zheng, Lin; Lu, Yi

    2011-05-01

    The magnetocaloric effect (MCE) in TbMnO3 single crystals was investigated by isothermal magnetization curves for the ab plane at low temperatures. Large magnetic entropy change, ΔSM = -18.0 J/kg K, and the refrigerant capacity, RC = 390.7 J/kg, are achieved near the ordering temperature of Tb3+ moment (TNTb) under 70 kOe along the a axis. Furthermore, the TbMnO3 single crystal exhibits a giant MCE anisotropy. The difference of ΔSMand RC between the a and b axes is field and temperature dependent, which reaches maximum values of 11.4 J/kg K and 304.1 J/kg, respectively. By taking magnetocrystalline anisotropy into account, the rotating ΔSMwithin the ab plane can be well simulated, indicating that the anisotropy of ΔSMis directly contributed from the magnetocrystalline anisotropy. Our finding for giant MCE anisotropy in TbMnO3 single crystals explores the possibility of using this material for magnetic refrigerators by rotating its magnetization vector rather than moving it in and out of the magnet.

  18. The effects of Tb substitution for La on the magnetic properties of LaFe11.5Si1.5 compound

    Science.gov (United States)

    Imam, H.; Zhang, H. G.; Xu, L.; Zhao, J. L.; Gao, X. X.; Yue, M.

    2018-05-01

    The structural and magnetic properties of La1-yTbyFe11.5Si1.5 compounds have been investigated. The substituted 5 percent of Tb has remarkably increased the maximum entropy change (-ΔSM) to a value of 25.2 J/kg·K. However, a further increase of Tb leads to a monotonous decrease in the entropy change, mainly due to phase separation. The Tb substitution also can lower the thermal and magnetic hysteresis loss of the system. Another feature of this replacement is that, with Tb content higher than 10 percent, the Curie temperature (TC) starts to increase and reaches 197 K when 30 percent of La is substituted. These results indicate that La1-yTbyFe11.5Si1.5 may be a promising candidate for magnetic refrigeration material in certain temperature range.

  19. The SM and MIR reactors operation experience

    International Nuclear Information System (INIS)

    Kuprienko, V.A.; Klinov, A.V.; Svyatkin, M.N.; Shamardin, V.K.

    1995-01-01

    The SM and MIR operation experience show that continuous work on the problem of ageing, in all its aspects, allows for prolongation of the research plant life cycle by several folds as compared to the initial project. The redesigned SM-3 reactor will operate for another 20 years. The similar result is expected from the MIR planned reconstruction which scope will be the topic of future presentations. (orig.)

  20. Promising therapy of XDR-TB/MDR-TB with thioridazine an inhibitor of bacterial efflux pumps

    DEFF Research Database (Denmark)

    Amaral, L; Martins, M; Viveiros, M

    2008-01-01

    -TB) - a M. tuberculosis organism that is resistant to the most effective second line drugs available for the treatment of TB. This review provides detailed, significant evidence that supports the use of an old neuroleptic compound, thioridazine (TZ), for the management of MDR-TB and XDR-TB infections...... therapy predictably ineffective and death is inevitable, compassionate therapy with TZ should be contemplated. The risks are small and the rewards great....

  1. Electronic and ionic transport in Ce0.8PrxTb0.2-xO2-δ and evaluation of performance as oxygen permeation membranes

    DEFF Research Database (Denmark)

    Chatzichristodoulou, Christodoulos; Hendriksen, Peter Vang

    2012-01-01

    is significantly enhanced relative to that of a Ce0.9Gd0.1O1.95-δ membrane at high oxygen activities of the permeate gas (aO2 an > 10-15) due to the enhanced electronic conductivity of the Ce0.8PrxTb0.2-xO2-δ compounds. Interference between the ionic and electronic flows has a significant positive effect......The electronic conductivity of Ce0.8PrxTb0.2-xO2-δ (x = 0, 0.05, 0.10, 0.15, 0.20) was determined in the oxygen activity range aO2 ≈ 103 to aO2 ≈ 10-17 at 700- 900 °C by means of Hebb-Wagner polarisation. The electronic conductivity of all the Ce0.8PrxTb0.2-xO2-δ compositions was significantly...... enhanced as compared to that of Ce0.9Gd0.1O1.95-δ, and its value was found to increase with increasing Pr/Tb ratio. The ionic mobility of Ce0.8PrxTb0.2-xO2-δ is similar to that of Ce1- 2δGd2δO2-δ at the same oxygen vacancy concentration. The calculated oxygen flux of a Ce0.8PrxTb0.2-xO2-δ membrane...

  2. Gamma ray irradiation characteristics of SM fibers

    International Nuclear Information System (INIS)

    Ito, Ryuichi; Okano, Hiroaki; Hashiba, Keichi; Nakai, Hisanori

    1987-01-01

    1.3 μm range single mode (SM) optical fibers have been used for wide application of mainly long distance communication. At present, in order to realize the larger capacity and longer distance between relay points, the development of 1.5 μm range SM fibers of low dispersion and small loss has been actively promoted. As for the radiation withstanding property of SM fibers, report is scarce. The authors reported on the gamma ray irradiation characteristics of 1.3 μm range SM fibers, but since 1.5 μm range SM fibers are designed with the different structure from that of 1.3 μm fibers, it is necessary to evaluate from new viewpoint. In this report, mainly on the structure having triangular distribution, the effect that the manufacturing condition and the structural defects of glass exert on the gamma ray irradiation characteristics is described. The specimens were mainly dispersion shift type fibers (DSF), and for comparison, single window, double window and 1.3 μm SM fibers were examined. Co-60 gamma ray was irradiated, and the optical loss and electron spin resonance were measured. By low temperature and low speed drawing, the good result in the optical loss was obtained. The presence of oxygen at the time of sintering materials had no effect. The dependence of the ESR on the drawing condition was not very remarkable. (Kako, I.)

  3. 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.

  4. Stop TB in My Lifetime: A Call for a World Free of TB - World TB Day 2013

    Centers for Disease Control (CDC) Podcasts

    2012-03-12

    In this podcast Dr. Kenneth Castro, Director of the Division of Tuberculosis Elimination, discusses World TB Day, the 2013 slogan and theme.  Created: 3/12/2012 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 3/13/2012.

  5. The association between ARV and TB drug resistance on TB treatment outcome among Kazakh TB/HIV patients.

    Science.gov (United States)

    Mishkin, Kathryn; Alaei, Kamiar; Alikeyeva, Elmira; Paynter, Christopher; Aringazina, Altyn; Alaei, Arash

    2018-02-26

    TB drug resistance poses a serious threat to the public health of Kazakhstan. This paper presents findings related to TB treatment outcome and drug resistant status among people coinfected with HIV and TB in Kazakhstan. Cohort study using data were provided by the Kazakhstan Ministry of Health's National Tuberculosis Program for 2014 and 2015. Chi-square and logistical regression were performed to understand factors associated with drug resistant TB status and TB treatment outcome. In bivariate analysis, drug resistant status was significantly associated with year of TB diagnosis (p=0.001) viral load (p=0.03). TB treatment outcome was significantly associated with age at diagnosis (p=01), ARV treatment (p <0.0001), and TB drug resistant status (p=0.02). In adjusted analysis, drug resistance was associated with increased odds of successful completion of treatment with successful result compared to treatment failure (OR 6.94, 95% CI: 1.39-34.44) CONCLUSIONS: Our results suggest that being drug resistant is associated with higher odds of completing treatment with successful outcome, even when controlling for receipt of ARV therapy. Copyright © 2018. Published by Elsevier Ltd.

  6. Structure, magnetism, and transport of single-crystalline R NiSi3 (R = Y, Gd-Tm, Lu)

    Science.gov (United States)

    Arantes, Fabiana R.; Aristizábal-Giraldo, Deisy; Masunaga, Sueli H.; Costa, Fanny N.; Ferreira, Fabio F.; Takabatake, Toshiro; Mendonça-Ferreira, Leticie; Ribeiro, Raquel A.; Avila, Marcos A.

    2018-04-01

    We report on the physical properties of the intermetallic series R NiSi3 (R =Y , Gd-Tm, Lu). High quality single crystals with platelike morphology were grown using the Sn flux method. X-ray powder diffraction data show that this series crystallizes in the orthorhombic space group Cmmm, and Laue patterns indicate that the b axis remains perpendicular to the plane of the plates. Magnetization measurements show anisotropic antiferromagnetic ground states for R = Gd-Tm with Néel temperatures ranging from TN=2.6 K (TmNiSi3) up to 32.2 K (TbNiSi3), as well as metamagnetic transitions that in some cases appear together with hysteresis (TbNiSi3,DyNiSi3, and HoNiSi3). The easy axis changes from a axis to b axis on going from R = Gd-Ho to R = Er-Tm. All transitions from antiferromagnetic to paramagnetic states are clearly marked by sharp peaks in specific heat as well as in the derivative of resistivity measurements, which show metallic temperature dependence for all compounds and residual values in the range of 1 μ Ω cm . DyNiSi3 has two close phase transitions, while HoNiSi3 presents distinct critical temperatures for applied fields in the a or c directions (10.4 and 6.3 K, respectively), pointing to possible component-specific ordering of the local magnetic moments.

  7. Curie temperature rising by fluorination for Sm2Fe17

    Directory of Open Access Journals (Sweden)

    Matahiro Komuro

    2013-02-01

    Full Text Available Fluorine atoms can be introduced to Sm2Fe17 using XeF2 below 423 K. The resulting fluorinated Sm2Fe17 powders have ferromagnetic phases containing Sm2Fe17FY1(0Sm2Fe17FY2 (1Sm2Fe17, and α-Fe. The unit cell for Sm2Fe17 is elongated by the fluorination. The largest unit cell volume among the rhombohedral Sm2Fe17 compounds is 83.8 nm3, which is 5.8% larger than Sm2Fe17. The rhombohedral Sm2Fe17 with the largest unit cell volume is dissociated above 873 K, and fluorination increases Curie temperature from 403 K for Sm2Fe17 to 675 K. This increase can be explained by the magneto-volume effect.

  8. μ+ depolarization in AlGd alloys

    International Nuclear Information System (INIS)

    Kohn, S.; Brown, J.A.; Heffner, R.H.; Huang, C.Y.; Kitchens, T.A. Jr.; Leon, M.; Olsen, C.E.; Schillaci, M.E.

    1979-01-01

    The μ + depolarization rate in dilute AlGd alloys containing 50 and 450 atomic ppm Gd was measured in a transverse field of 80 Oe over the temperature range 6-300 K. For both alloys, Λ increased dramatically above 200 K, reaching values of 0.69 and 0.93 μs -1 , respectively, near room temperature. The results are interpreted as providing evidence for a thermally-activated trapping mechanism. (Auth.)

  9. Extensively Drug-Resistant Tuberculosis (XDR TB)

    Science.gov (United States)

    ... TB Reference Laboratory Network, the National TB Surveillance System in the United States, the national reference laboratory of South Korea, and ... capacity in the U.S. and abroad; and Developing education, risk, and media communications ... – United States, 1993–2006 CDC. CDC’s Role in Preventing XDR ...

  10. TB Testing for People Living with HIV

    Centers for Disease Control (CDC) Podcasts

    2012-07-23

    Dr. Kenneth Castro, Director of the Division of Tuberculosis Elimination, explains why it is important for people living with HIV to be tested for TB.  Created: 7/23/2012 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 7/23/2012.

  11. 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.

  12. 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)

  13. Effect of terbium substitution on the magnetocaloric properties of Gd3Ga5O12

    International Nuclear Information System (INIS)

    Reshmi, C.P.; Savitha Pillai, S.; Varma, Manoj Raama; Suresh, K.G.

    2011-01-01

    The magnetic refrigeration is an environment friendly cooling technology based on magnetocaloric effect. The most crucial ingredient behind a magnetic refrigerator is a magnetic material which possesses large magnetocaloric effect. Certain materials when placed in a magnetic field suddenly get heats up and suddenly cooled down by the application and the removal of magnetic field due to their change in entropy. This is measured either in terms of isothermal entropy change and adiabatic temperature change observed when the applied magnetic field is varied. The refrigerators which operate below 15K have applications in liquefying helium and for the development of space based cooling system for the space crafts. The material of choice in this temperature range is rare earth gallium garnets. Rare earth garnets are complex ceramic oxides having the chemical formula A 3 B 2 C 3 O 12 have attracted attention due to their interesting magnetic properties. The magnetism in R 3 Ga 5 O 12 is due to the exchange interaction between the rare earth spins. In the proposed work we have chosen Gd 3 Ga 5 O 12 as parent material, substituted Tb systematically in the place of Gd. The structural studies were done by using Rietveld analysis of X-Ray diffraction. There is a systematic variation of volume and lattice parameter upon substitution of Tb. The magnetic characterizations were done by a vibrating sample magnetometer. The experimental magnetic moments of the materials were calculated from the M-T curve by using Curie-Weiss fit and are good agreement with the theoretical values. There is a systematic increase of magnetic moments by Tb substitution. The magnetocaloric effect is calculated by using the integrated Maxwell's relation from the magnetization data. At low magnetic fields the Tb substituted compounds show good MCE values than GGG. Tb substitution enhances the magnetocaloric effect at low magnetic fields and the ΔS M values are higher for x = 1 and 3 at 1T. Hence these

  14. Understanding social context on TB cases

    Science.gov (United States)

    Ariyanto, Y.; Wati, D. M.

    2017-01-01

    Tuberculosis (TB) nowadays still becomes one of the world’s deadliest communicable disease. More than half were in South-East Asia and Western Pacific Regions, including Indonesia. As developing country, Indonesia remains classic problems in overcoming TB, that is discontinuation on treatment. Most of discontinuation on treatment among TB patients are affected by diagnostic delay that caused by patient delay. These phenomena occur in many areas, rural to suburb, coastal to plantation, and so on, and they are related with social context among community that could be social capital for each community to deal with TB. Jember as one of county in East Java is known as plantation area. It also has a high prevalence of TB. This study focused on understanding about social context among community, especially on plantation area. This cross-sectional study involved in three districts of Jember, those are Tanggul, Pakusari, and Kalisat. The data were obtained directly from the TB patients, local community, and Primary Health Care (PHC) where the patients recorded. Spatial analysis and social network analysis (SNA) were applied to obtain health seeking behavior pattern among the TB patients coincide the community. Most of TB patients had already chosen health professionals to lead the treatment, although some of them remained to choose self-medication. Meanwhile, SNA showed that religious leader was considered as main part of countermeasures of TB. But they didn’t ever become central figures. So it can be concluded that there are other parts among community who can contribute due to combatting on TB.

  15. HIV/TB co-infection:perspectives of TB patients and providers on the integrated HIV/TB pilot program in Tamilnadu, India

    OpenAIRE

    Lakshminarayanan, Mahalakshmi

    2009-01-01

    The WHO recommends routine HIV testing among TB patients as a key strategy to combat the dual HIV/TB epidemic. India has integrated its HIV and TB control programs and is offering provider initiated HIV testing for all TB patients since 2007. Using a mixed methods approach, this study aims to understand the perspectives of TB patients and providers on the integrated HIV/TB pilot program in Tamilnadu, India. A survey conducted by the Tuberculosis Research Center, India on 300 TB patients is th...

  16. Description and exploitation of benchmarks involving {sup 149}Sm, a fission product taking part of the burn up credit in spent fuels

    Energy Technology Data Exchange (ETDEWEB)

    Anno, J.; Poullot, G. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire; Fouillaud, P.; Grivot, P. [CEA Centre d`Etudes de Valduc, 21 - Is-sur-Tille (France)

    1995-12-31

    Up to now, there was no benchmark to validate the Fission Products (FPs) cross sections in criticality safety calculations. The protection and nuclear safety institute (IPSN) has begun an experimental program on 6 FPs ({sup 103}Rh, {sup 133}Cs, {sup 143}Nd, {sup 149}Sm, {sup 152}Sm, and {sup 155}Gd daughter of {sup 155}Eu) giving alone a decrease of reactivity equal to half the whole FPs in spent fuels (except Xe and I). Here are presented the experiments with the {sup 149}Sm and the results obtained with the APOLLO I-MORET III calculations codes. 11 experiments are carried out in a zircaloy tank of 3.5 1 containing slightly nitric acid solutions of Samarium (96,9% in weight of {sup 149S}m) at 0.1048 -0.2148 - 0.6262 g/l concentrations. It was placed in the middle of arrays of UO{sub 2} rods (4.742 % U5 weight %) at square pitch of 13 mm. The underwater height of the rods is the critical parameter. In addition, 7 experiments were performed with the same apparatus with water and boron proving a good experimental representativeness and a good accuracy of the calculations. As the reactivity worth of the Sm tank is between 2000 and 6000 10{sup -5}, the benchmarks are well representative and the cumulative absorption ratios show that {sup 149}Sm is well qualified under 1 eV. (authors). 8 refs., 7 figs., 6 tabs.

  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. High spin states in 143Sm

    International Nuclear Information System (INIS)

    Raut, R.; Ganguly, S.; Kshetri, R.; Banerjee, P.; Bhattacharya, S.; Dasmahapatra, B.; Mukherjee, A.; Mukherjee, G.; Sarkar, M. Saha; Goswami, A.; Gangopadhyay, G.; Mukhopadhyay, S.; Krishichayan,; Chakraborty, A.; Ghughre, S. S.; Bhattacharjee, T.; Basu, S. K.

    2006-01-01

    The high spin states of 143 Sm have been studied by in-beam γ-spectroscopy following the reaction 130 Te( 20 Ne,7n) 143 Sm at E lab =137 MeV, using a Clover detector array. More than 50 new gamma transitions have been placed above the previously known J π =23/2 - , 30 ms isomer at 2795 keV. The level scheme of 143 Sm has been extended up to 12 MeV and spin-parity assignments have been made to most of the newly proposed level. Theoretical calculation with the relativistic mean field approach using blocked BCS method, has been performed. A sequence of levels connected by M1 transitions have been observed at an excitation energy ∼8.6 MeV. The sequence appears to be a magnetic rotational band from systematics

  19. 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.

  20. 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.

  1. Sm 3+-doped polymer optical waveguide amplifiers

    Science.gov (United States)

    Huang, Lihui; Tsang, Kwokchu; Pun, Edwin Yue-Bun; Xu, Shiqing

    2010-04-01

    Trivalent samarium ion (Sm 3+) doped SU8 polymer materials were synthesized and characterized. Intense red emission at 645 nm was observed under UV laser light excitation. Spectroscopic investigations show that the doped materials are suitable for realizing planar optical waveguide amplifiers. About 100 μm wide multimode Sm 3+-doped SU8 channel waveguides were fabricated using a simple UV exposure process. At 250 mW, 351 nm UV pump power, a signal enhancement of ˜7.4 dB at 645 nm was obtained for a 15 mm long channel waveguide.

  2. 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)

  3. 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)

  4. An investigation of the Pd-Ag-Ru-Gd quaternary system phase diagram

    International Nuclear Information System (INIS)

    Zhang Kanghou; Xu Yun

    2005-01-01

    On the basis of the Ag-Pd-Gd, Ag-Ru-Gd and Pd-Ru-Gd ternary systems, the partial phase diagram of Pd-Ag-Ru-Gd (Gd 3 Gd and Ag 51 Gd 14 ; five two-phase regions: Pd(Ag) + (Ru), Pd(Ag) + Ag 51 Gd 14 (Ru) + Ag 51 Gd 14 , Pd(Ag) + Pd 3 Gd and (Ru) + Pd 3 Gd; three three-phase regions: Pd(Ag) + Pd 3 Gd + (Ru), Pd(Ag) + Ag 51 Gd 14 + (Ru) and (Ru) + Ag 51 Gd 14 + Pd 3 Gd; one four-phase region Pd(Ag) + (Ru) + Ag 51 Gd 14 + Pd 3 Gd. No new quaternary intermetallic phase has been found

  5. 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

  6. 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.

  7. Luminescent properties of Tb doped gadolinium aluminate nanophosphors for display and forensic applications

    Directory of Open Access Journals (Sweden)

    P.K. Jisha

    2017-12-01

    Full Text Available A novel green light emitting GdAlO3:Tb3+ (1–11 mol% nanophosphor has been synthesized by the solution combustion method and the final products were characterized. The energy band gap of the samples was estimated in the range of 5.13–5.88 eV from diffuse reflectance spectra. The effect of the added Tb3+ ions on the electronic structure was considered based on the absolute electronegativity. The characteristic photoluminescence emission corresponding to the transition 5D4→7Fj (j = 6, 5, 4, 3 of the Tb3+ ions was observed in the wavelength range of 500–650 nm, and assigned due to the f–f transitions upon the 378 nm excitation. The optimized nanophosphor was found suitable for applications in the latent fingerprint detection. The photometric characterization has revealed the excellent color chromaticity coordinates and the correlated color temperature levels. They are on the same level of commercial phosphors and quite useful for green WLEDs, solid state displays and forensic applications as well.

  8. Magnetic short-range order in Gd

    International Nuclear Information System (INIS)

    Child, H.R.

    1978-01-01

    The magnetic short-range order in a ferromagnetic, isotopically enriched 160 Gd metal single crystal has been investigated by quasielastic scattering of 81-meV neutrons. Since Gd behaves as an S-state ion in the metal, little anisotropy is expected in its magnetic behavior. However, the data show that there is anisotropic short-range order present over a large temperature interval both above and below T/sub C/. The data have been analyzed in terms of an Ornstein-Zernike Lorentzian form with anisotropic correlation ranges. These correlation ranges as deduced from the observed data behave normally above T/sub C/ but seem to remain constant over a fairly large interval below T/sub C/ before becoming unobservable at lower temperatures. These observations suggest that the magnetic ordering in Gd may be a more complicated phenomenon than first believed

  9. Fabrication and photoluminescence properties of color-tunable light emitting lanthanide doped GdVO4 hierarchitectures

    International Nuclear Information System (INIS)

    Amurisana, Bao; Bao, Lihong; Bao, Liang; Tegus, O.

    2017-01-01

    The flower-like GdVO 4 :Ln 3+ ( Ln 3+ =Eu 3+ , Dy 3+ , Sm 3+ , Tm 3+ ) hierarchitectures have been successfully synthesized on a glass slide substrate through a one-pot hydrothermal route assisted by disodium ethylenediaminetetraacetic acid (Na 2 H 2 L, where L 4- =(CH 2 COO) 2 N(CH 2 ) 2 N(CH 2 COO) 2 4- ). A high density and ordered flower-like GdVO 4 :Ln 3+ hierarchitectures grew epitaxially on glass substrate. The as-prepared flower-like architectures with the size about 6 μm are constructed by the numerous radially oriented single-crystalline nanorods with the width from 20 nm to 200 nm and the length from 500 nm to 3 μm. The morphologies, the thickness, and the density of as-grown flower clusters can be readily tuned by tailoring the growth time and Na 2 H 2 L/Gd 3+ molar ratio. The possible formation mechanism of flower-like GdVO 4 :Ln 3+ hierarchitectures is discussed on the basis of the results from the controlled experiments under hydrothermal conditions. Because of an energy transfer from vanadate groups to dopants, the flower-like GdVO 4 :Ln 3+ ( Ln 3+ =Eu 3+ , Dy 3+ , Sm 3+ and Tm 3+ ) superstructures showed strong characteristic dominant emissions of the Eu 3+ , Dy 3+ , Sm 3+ and Tm 3+ ions at 617 nm ( 5 D 0 → 7 F 2 , strong red), 575 nm ( 4 F 9/2 → 6 H 13/2 , yellow), 604 nm ( 4 G 5/2 → 6 H 7/2 , orange-red) and 476 nm ( 1 G 4 – 3 H 6 , blue) under ultraviolet excitation, respectively.Further, the emission color of the product can also be tuned by selecting the dopant Ln 3+ with characteristic emissions and varying the concentration ratio of co-doping activators. This approach could be extended to the fabrication of hierarchical structures for other oxide micro/nanomaterials, and may provide a general way to achieve multicolor-tunable emission for many applications.

  10. Magnetic and transport properties of amorphous ferro magnetic Gd--Au, Gd--Ni and Gd--Co alloys obtained by splat-cooling

    International Nuclear Information System (INIS)

    Durand, J.; Poon, S.J.

    1977-06-01

    We present the results of magnetization and transport measurements on the amorphous Gd 80 Au 20 , Gd 68 Ni 32 and Gd 67 Co 33 alloys over a temperature range of 1.8 to 300 0 K in fields up to 75 kOe. These ferromagnetic alloys obtained by splat-cooling have Curie temperatures T/sub c/ of 150, 125 and 175 0 K, respectively. The saturation moment per Gd atom extrapolated to 0 0 K is estimated to be 7 +- 0.1 μ/sub B/. The exchange integrals for Gd-Au and Gd-Ni are determined from the value of T/sub c/ and from the temperature dependence of the saturation magnetization. The zero-field resistivity for Gd-Ni and Gd-Co exhibits maxima around T/sub c/. We present some preliminary results of magnetoresistivity measurements with applied field parallel and perpendicular to the foil plane. The anisotropy is in-plane for Gd-Co. For the Gd-Au and Gd-Ni alloys, there is no well-defined easy axis

  11. Magnetic properties of ball-milled TbFe2 and TbFe2B

    Indian Academy of Sciences (India)

    Unknown

    1. Introduction. The RFe2 (R = rare earth) Laves phase compounds are known to possess large cubic anisotropy (Clark et al 1972) and highest Curie temperature (TC) of all RT2 compounds. (T = transition metal). RFe2 ... TbFe2 and TbFe2B were prepared by arc melting the high pure elements (Tb and B, 99⋅9% purity; Fe, ...

  12. Host markers in Quantiferon supernatants differentiate active TB from latent TB infection: preliminary report

    Directory of Open Access Journals (Sweden)

    Walzl Gerhard

    2009-05-01

    Full Text Available Abstract Background Interferon gamma release assays, including the QuantiFERON® TB Gold In Tube (QFT have been shown to be accurate in diagnosing Mycobacterium tuberculosis infection. These assays however, do not discriminate between latent TB infection (LTBI and active TB disease. Methods We recruited twenty-three pulmonary TB patients and 34 household contacts from Cape Town, South Africa and performed the QFT test. To investigate the ability of new host markers to differentiate between LTBI and active TB, levels of 29 biomarkers in QFT supernatants were evaluated using a Luminex multiplex cytokine assay. Results Eight out of 29 biomarkers distinguished active TB from LTBI in a pilot study. Baseline levels of epidermal growth factor (EGF soluble CD40 ligand (sCD40L, antigen stimulated levels of EGF, and the background corrected antigen stimulated levels of EGF and macrophage inflammatory protein (MIP-1β were the most informative single markers for differentiation between TB disease and LTBI, with AUCs of 0.88, 0.84, 0.87, 0.90 and 0.79 respectively. The combination of EGF and MIP-1β predicted 96% of active TB cases and 92% of LTBIs. Combinations between EGF, sCD40L, VEGF, TGF-α and IL-1α also showed potential to differentiate between TB infection states. EGF, VEGF, TGF-α and sCD40L levels were higher in TB patients. Conclusion These preliminary data suggest that active TB may be accurately differentiated from LTBI utilizing adaptations of the commercial QFT test that includes measurement of EGF, sCD40L, MIP-1β, VEGF, TGF-α or IL-1α in supernatants from QFT assays. This approach holds promise for development as a rapid diagnostic test for active TB.

  13. Ni3d-Gd4f correlation effects on the magnetic behaviour of GdNi

    Energy Technology Data Exchange (ETDEWEB)

    Paulose, P L [Tata Inst. of Fundamental Research, Bombay (India); Patil, Sujata [Tata Inst. of Fundamental Research, Bombay (India); Mallik, R [Tata Inst. of Fundamental Research, Bombay (India); Sampathkumaran, E V [Tata Inst. of Fundamental Research, Bombay (India); Nagarajan, V [Tata Inst. of Fundamental Research, Bombay (India)

    1996-07-01

    The results of magnetization and heat-capacity measurements on the alloys, Gd{sub 1-x}Y{sub x}Ni (x=0.0, 0.25, 0.5, 0.75 and 0.9) are reported. The data suggest that there is a Gd induced magnetic moment on Ni, which may in turn enhance Gd-Gd exchange interaction strength in GdNi. The induced moment (on Ni) apparently exhibits itinerant ferromagnetism in the magnetically ordered state of GdNi. (orig.).

  14. Photoluminescence related to Gd3+:N-vacancy complex in GaN:Gd multi-quantum wells

    International Nuclear Information System (INIS)

    Almokhtar, Mohamed; Emura, Shuichi; Koide, Akihiro; Fujikawa, Takashi; Asahi, Hajime

    2015-01-01

    Highlights: • We grew Gd-doped GaN multi-quantum wells (MQWs) with quantum layer thickness of one nm by MBE. • The X-ray absorption near edge structure spectra observed at Gd LIII-edge indicate a nitrogen vacancy adjacent to Gd substituting the Ga ion in Gd-doped GaN MQW. • The photoluminescence of the samples is discussed considering the formation of a Gd 3+ :Nitrogen-vacancy complex. • A model is presented considering exciton-polaron formation trapped in defect sites around the Gd 3+ :N-vacancy complex in Gd-doped GaN MQWs. - Abstract: The photoluminescence of Gd-doped GaN multi-quantum wells (MQWs) is presented and discussed considering the formation of a Gd 3+ :Nitrogen-vacancy (N-vacancy) complex. A lower energy photoluminescence peak was observed for the Gd-doped GaN MQW sample with respect to the main peak assigned to a neutral donor bound exciton (D 0 X) of the undoped GaN MQW sample. The X-ray absorption near edge structure spectrum observed at Gd L III -edge indicates a nitrogen vacancy adjacent to the Gd substituting the Ga ion in Gd-doped GaN MQW sample. Local stresses around the Gd dopants in Gd-doped GaN matrix generated due to the larger diameter of the Gd 3+ ion with respect to the Ga 3+ ion can be relieved by the creation of vacancies. The lower formation energy of N-vacancies in GaN matrix introduce them as a preferred candidate to relieve the generated stresses. A Gd 3+ :N-vacancy complex consisting of a Gd 3+ ion and the created nitrogen vacancy adjacent to the Gd 3+ dopant is likely to form in GaN:Gd matrix. The lower photoluminescence peak energy observed in the Gd-doped GaN MQW sample is assigned to the recombination of an exciton captured at the Gd 3+ :N-vacancy complex forming a small polaron-like state. A model is presented considering the small exciton-polaron population in defect sites captured around the Gd 3+ ions in the Gd-doped GaN

  15. Gd-DTPA-enhanced dynamic MR imaging

    International Nuclear Information System (INIS)

    Frank, J.A.; Choyke, P.L.; Carvlin, M.; Inscoe, S.; Austin, H.; Dwyer, A.J.; Girton, M.; Black, J.

    1988-01-01

    This paper describes dynamic enhanced renal MR imaging, a new method of identifying specific derangements in renal function. Various diuretics were employed in 45 animal experiments to demonstrate the effects on the normal renal enhancement pattern (EP) after Gd-DTPA. Since different diuretics, osmotic (O), carbonic anhydrase (CA), and loop (L), are active at different sites, specific EP alterations are observed. Imaging was performed with 32 5.1-second sequential gradient recalled acquisition in a steady state images following a bolus of Gd-DTPA

  16. 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

  17. Providing an address for delivery of nanoencapsulated TB drugs

    CSIR Research Space (South Africa)

    Lemmer, Yolandy

    2010-06-01

    Full Text Available compliance and drug resistance pose a great challenge to TB treatment programs worldwide. To improve the current inadequate therapeutic management of TB, a polymeric anti-TB nanodrug delivery system, for anti-TB drugs, was developed that could enable entry...

  18. HIV-Associated TB: Facts 2013

    Science.gov (United States)

    ... 2012 . Around 75% of these people live in sub-Saharan Africa.  TB is the leading cause of death among ... adopted by policy makers and implemented by all health facilities offering HIV care services.  The number of ...

  19. Thermally stimulated properties in ZnSe:Tb and ZnSe:(Mn, Tb) phosphors

    Science.gov (United States)

    Mishra, A. K.; Mishra, S. K.; Pandey, S. P.; Lakshmi Mishra, Kshama

    2018-02-01

    Thermoluminescence studies were performed of ZnSe:Tb and ZnSe:(Mn, Tb) phosphors. A method of preparation for ZnSe phosphors doped with Tb and (Mn, Tb) has been discussed. The thermoluminescence (TL) properties of these phosphors have been studied from 100 to 370 K temperature after exciting by UV radiation (365 nm) at three uniform heating rates 0.4, 0.6 and 0.9 K/s. The trapping parameters like trap depth, lifetime of electrons and capture cross-section have also been determined using various methods.

  20. Immunomodulation by vitamin D: implications for TB

    OpenAIRE

    Chun, Rene F; Adams, John S; Hewison, Martin

    2011-01-01

    TB remains a major cause of mortality throughout the world. Low vitamin D status has been linked to increased risk of TB and other immune disorders. These observations suggest a role for vitamin D as a modulator of normal human immune function. This article will detail the cellular and molecular mechanisms by which vitamin D regulates the immune system and how vitamin D insufficiency may lead to immune dysregulation. The importance of vitamin D bioavailability as a mechanism for defining the ...

  1. 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.)

  2. 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

  3. Magnetic and transport properties of sputtered Gd-Y multilayers

    International Nuclear Information System (INIS)

    Freitas, P.P.; From, M.; Melo, L.V.

    1991-01-01

    Gd-Y-Gd multilayers were prepared that show a magnetoresistance enhancement for an Y layer separation of 30 A. This magnetoresistance enhancement is an interface effect and occurs in samples where some degree of antiferromagnetic coupling is present

  4. Characterization of element and mineral content in Artemisia annua ...

    African Journals Online (AJOL)

    Dr DIALLO

    2013-06-26

    Jun 26, 2013 ... The mineral elements are present in different kinds of herbal leaves in various proportions .... rare earth elements (Dy, Eu, Gd, Sm, Tb and Yb) were not detected in ..... behaviour of leached aluminum in tea infusions. The Sci.

  5. 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)

  6. New AMS method to measure the atom ratio {sup 146}Sm/{sup 147}Sm for a half-life determination of {sup 146}Sm

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, N. [Tandem Accelerator Complex, Research Facility Center for Science and Technology, University of Tsukuba (Japan); Paul, M., E-mail: paul@vms.huji.ac.il [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Alcorta, M. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Bowers, M.; Collon, P. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556-5670 (United States); Deibel, C.M. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 46624 (United States); DiGiovine, B. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Goriely, S. [Universite Libre de Bruxelles, CP-226, Brussels 1050 (Belgium); Greene, J.P.; Henderson, D.J.; Jiang, C.L. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Kashiv, Y. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556-5670 (United States); Kay, B.P.; Lee, H.Y.; Marley, S.T. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Nakanishi, T. [Faculty of Chemistry, Institute of Science and Engineering, Kanazawa University (Japan); Pardo, R.C.; Patel, N.; Rehm, K.E. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Robertson, D. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556-5670 (United States); and others

    2013-01-15

    The extinct p-process nuclide {sup 146}Sm (t{sub 1/2} = 103 {+-} 5 Myr) is known to have been present in the Early-Solar System and has been proposed as an astrophysical chronometer. {sup 146}Sm is also intensely used to date meteorite and planetary differentiation processes, enhancing the importance of an accurate knowledge of the {sup 146}Sm half-life. We are engaged in a new determination of the {sup 146}Sm half-life in which the {sup 146}Sm/{sup 147}Sm atom ratio is determined by accelerator mass spectrometry at the ATLAS facility of Argonne National Laboratory. In order to reduce systematic errors in the AMS determination of the {sup 146}Sm/{sup 147}Sm ratios (in the range of 10{sup -7}-10{sup -9}), {sup 146}Sm and {sup 147}Sm ions were alternately counted in the same detector in the focal plane of a gas-filled magnet, respectively in continuous-wave and attenuated mode. Quantitative attenuation is obtained with the 12 MHz pulsed and ns-bunched ATLAS beam by chopping beam pulses with an RF sweeper in a ratio (digitally determined) down to 1:10{sup 6}. The experiments and preliminary results are discussed.

  7. 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.

  8. 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...

  9. Multipole mixing ratios in /sup 154/Gd

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Won Mo; Song, Choong Sik; Joo, Koan Sik

    1985-06-01

    We have measured gamma-gamma angular correlations to determine the mixing ratios of several gamma transitions in /sup 154/Gd. The results are compared with those derived from the pairing-plus-quadrupole model and from the interacting boson model.

  10. 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)

  11. 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

  12. 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...

  13. 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, ...

  14. Hyperfine structure in the Gd II spectrum and the nuclear electric quadrupole moment of 157Gd

    International Nuclear Information System (INIS)

    Clieves, H.P.; Steudel, A.

    1979-01-01

    The hyperfine structure of 157 Gd was investigated in 20 Gd II lines by means of a photoelectric recording Fabry-Perot interferometer with digital data processing. The hyperfine splitting factors, A and B, were obtained by computer fits to the observed line structures. Using a multiconfigurational set of wave functions in intermediate coupling derived by Wyart, mono-electronic parameters were deduced by a parametric treatment. The nuclear electric quadrupole moment of 157 Gd was evaluated from the quadrupole interaction of the 5d electron in 4f 7 5d6s, the 5d electron in 4f 7 5d6p, and the 6p electron in 4f 7 5d6p. The three values obtained for the quadrupole moment agree very well. The final result, corrected for Sternheimer shielding, is Q( 157 Gd) = 1.34(7) x 10 -24 cm 2 . (orig.) [de

  15. Measurement of Gd content in (U,Gd)O2 using thermal gravimetric analysis

    International Nuclear Information System (INIS)

    Kim, Keon Sik; Yang, Jae Ho; Kang, Ki Won; Song, Kun Woo; Kim, Gil Moo

    2004-01-01

    We propose a simple and precise method for measuring the Gd content in the (U,Gd)O 2 pellet by only measuring the weight variation of the pellet during thermal heat treatment in air. The (U,Gd)O 2 fuel pellets were oxidized at 475 deg. C, subsequently heat treated at 1300 deg. C, and then cooled to room temperature in air. The accompanying weight variations were measured using thermo gravimetric analysis (TGA). The measured weight variations were mathematically analyzed with reference to the successive phase reactions during the heat treatment. This method provides an advantage in that the rare-earth element content including Gd can be measured using relatively simple equipment such as an electric furnace and a balance

  16. Luminescence Properties of Self-Aggregating TbIII-DOTA-Functionalized Calix[4]arenes

    Directory of Open Access Journals (Sweden)

    Florian Mayer

    2018-01-01

    Full Text Available Self-aggregating calix[4]arenes carrying four DOTA ligands on the upper rim for stable complexation of paramagnetic GdIII-ions have already been proposed as MRI probes. In this work, we investigate the luminescence properties of TbIII-DOTA-calix[4]arene-4OPr containing four propyl-groups and compare them with those of the analog substituted with a phthalimide chromophore (TbIII-DOTA-calix[4]arene-3OPr-OPhth. We show that, given its four aromatic rings, the calix[4]arene core acts as an effective sensitizer of Tb-centered luminescence. Substituents on the lower rim can modulate the aggregation behavior, which in turn determines the luminescence properties of the compounds. In solid state, the quantum yield of the phthalimide derivative is almost three times as high as that of the propyl-functionalized analog demonstrating a beneficial role of the chromophore on Tb-luminescence. In solution, however, the effect of the phthalimide group vanishes, which we attribute to the large distance between the chromophore and the lanthanide, situated on the opposite rims of the calix[4]arene. Both quantum yields and luminescence lifetimes show clear concentration dependence in solution, related to the strong impact of aggregation on the luminescence behavior. We also evidence the variability in the values of the critical micelle concentration depending on the experimental technique. Such luminescent calix[4]arene platforms accommodating stable lanthanide complexes can be considered valuable building blocks for the design of dual MR/optical imaging probes.

  17. 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.

  18. Description and exploitation of benchmarks involving 149Sm, a fission product taking part of the burn up credit in spent fuels

    International Nuclear Information System (INIS)

    Anno, J.; Poullot, G.

    1995-01-01

    Up to now, there was no benchmark to validate the Fission Products (FPs) cross sections in criticality safety calculations. The protection and nuclear safety institute (IPSN) has begun an experimental program on 6 FPs ( 103 Rh, 133 Cs, 143 Nd, 149 Sm, 152 Sm, and 155 Gd daughter of 155 Eu) giving alone a decrease of reactivity equal to half the whole FPs in spent fuels (except Xe and I). Here are presented the experiments with the 149 Sm and the results obtained with the APOLLO I-MORET III calculations codes. 11 experiments are carried out in a zircaloy tank of 3.5 1 containing slightly nitric acid solutions of Samarium (96,9% in weight of 149S m) at 0.1048 -0.2148 - 0.6262 g/l concentrations. It was placed in the middle of arrays of UO 2 rods (4.742 % U5 weight %) at square pitch of 13 mm. The underwater height of the rods is the critical parameter. In addition, 7 experiments were performed with the same apparatus with water and boron proving a good experimental representativeness and a good accuracy of the calculations. As the reactivity worth of the Sm tank is between 2000 and 6000 10 -5 , the benchmarks are well representative and the cumulative absorption ratios show that 149 Sm is well qualified under 1 eV. (authors). 8 refs., 7 figs., 6 tabs

  19. Non-adherence to anti-TB drugs among TB/HIV co-infected patients ...

    African Journals Online (AJOL)

    Non-adherence to anti-TB drugs among TB/HIV co-infected patients in Mbarara Hospital ... and its associated factors have not been studied in these patients in Uganda. ... Methods: A cross-sectional study with qualitative and quantitative data ...

  20. tb diagnostics challenges of tb diagnosis and treatment in south africa

    African Journals Online (AJOL)

    2007-06-01

    Jun 1, 2007 ... 45 currently provides treatment to 3 000 patients. Eighty-nine per cent of those accessing ART have symptomatic HIV disease. (WHO clinical stage 3 and 4) with a median CD4 cell count of. 95 cells/µl. More than 50% have a history of prior completed. TB treatment, 15% are on current TB treatment, 11% are.

  1. Integration of TB and ART services fails to improve TB treatment ...

    African Journals Online (AJOL)

    The median CD4+ count of HIV-positive patients was 152 cells/μl (interquartile range (IQR) 71 - 277) for integrated facilities and 148 cells/μl (IQR 67 - 260) for single-service facilities. There was no statistical difference in the TB treatment outcome profile between integrated and single-service facilities for all TB patients (p=0.

  2. 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

  3. Host composition dependent tunable multicolor emission in the single-phase Ba2(Ln(1-z)Tb(z))(BO3)2Cl:Eu phosphors.

    Science.gov (United States)

    Xia, Zhiguo; Zhuang, Jiaqing; Meijerink, Andries; Jing, Xiping

    2013-05-14

    A new strategy based on the host composition design has been adopted to obtain efficient color-tunable emission from Ba2Ln(0.97-z)Tb(z)(BO3)2Cl:0.03Eu (Ln = Y, Gd and Lu, z = 0-0.97) phosphors. This study reveals that the single-phase Ba2Ln(1-z)Tb(z)(BO3)2Cl compounds can be applied to use allowed Eu(2+) absorption transitions to sensitize Eu(3+) emission via the energy transfer Eu(2+) → (Tb(3+))n → Eu(3+). The powder X-ray diffraction (XRD) and Rietveld refinement analysis shows single-phase Ba2Ln(1-z)Tb(z)(BO3)2Cl. As-prepared Ba2Ln(0.97-z)Tb(z)(BO3)2Cl:0.03Eu phosphors show intense green, yellow, orange and red emission under 377 nm near ultraviolet (n-UV) excitation due to a variation in the relative intensities of the Eu(2+), Tb(3+) and Eu(3+) emission depending on the Tb content (z) in the host composition, allowing color tuning. The variation in emission color is explained by energy transfer and has been investigated by photoluminescence and lifetime measurements and is further characterized by the Commission Internationale de l'éclairage (CIE) chromaticity indexes. The quantum efficiencies of the phosphors are high, up to 74%, and show good thermal stabilities up to 150 °C. This investigation demonstrates the possibility to sensitize Eu(3+) line emission by Eu(2+)via energy migration over Tb(3+) resulting in efficient color tunable phosphors which are promising for use in solid-state white light-emitting diodes (w-LEDs).

  4. Influence of annealing and nitrogenation on structure and magnetic properties of mechanically alloyed Sm-Fe powders

    Energy Technology Data Exchange (ETDEWEB)

    Teresiak, A.; Kubis, M.; Mattern, N.; Wolf, M.; Mueller, K.-H. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany)

    1998-07-01

    Sm-Fe-N compounds were prepared by mechanical alloying, subsequent annealing and nitrogenation. For crystal structure investigations of the non-equilibrium phases Sm{sub 2}Fe{sub 17+x} and Sm{sub 2}Fe{sub 17+x}N{sub y}, respectively, formed at the various annealing temperatures T{sub A}, XRD with following Rietveld analysis was used. For T{sub A} between 600 C and 750 C a modified hexagonal TbCu{sub 7} structure (space group P6/mmm) was found in which the Fe(2c) site is replaced by the partially (1/3) and randomly occupied Fe(61) site. The approximated composition is SmFe{sub 8.8-9.0}. The nitrogenated alloys crystallize in the same structure for 600 C < T{sub A} < 700 C. In this case the interstitial nitrogen randomly occupies the 3f site partially (1/3). For 800 C {<=} T{sub A} {<=} 900 C a disordered modified Th{sub 2}Zn{sub 17} structure (space group R anti 3m) was found that is formed by introducing additional Fe (6c) and Sm(3a) positions. The degree of order of the Sm- and Fe-atoms in c-direction increases with increasing annealing temperature. The completely ordered stoichiometric Sm{sub 2}Fe{sub 17} structure could not be reached by annealing the ball milled elemental powders. The nitrided alloys already form this intermediate structure at T{sub A} = 750 C. The interstitial nitrogen occupies the 9e site. The estimated nitrogen content is higher in the hexagonal phases than in the rhombohedral phase. Optimum magnetic properties, in particular a coercitivity {mu}{sub 01}H{sub C} = 3.7 T and a good squareness of the demagnetization curve, were obtained for T{sub A} = 750 C. Here we found a nitrogen content of y = 3 for Sm{sub 2}Fe{sub 17+x}N{sub y}. (orig.)

  5. Superconductivity at 43K in SmFeAsO1-xFx

    Science.gov (United States)

    Chen, X. H.; Wu, T.; Wu, G.; Liu, R. H.; Chen, H.; Fang, D. F.

    2008-06-01

    Since the discovery of high-transition-temperature (high-Tc) superconductivity in layered copper oxides, extensive effort has been devoted to exploring the origins of this phenomenon. A Tc higher than 40K (about the theoretical maximum predicted from Bardeen-Cooper-Schrieffer theory), however, has been obtained only in the copper oxide superconductors. The highest reported value for non-copper-oxide bulk superconductivity is Tc = 39K in MgB2 (ref. 2). The layered rare-earth metal oxypnictides LnOFeAs (where Ln is La-Nd, Sm and Gd) are now attracting attention following the discovery of superconductivity at 26K in the iron-based LaO1-xFxFeAs (ref. 3). Here we report the discovery of bulk superconductivity in the related compound SmFeAsO1-xFx, which has a ZrCuSiAs-type structure. Resistivity and magnetization measurements reveal a transition temperature as high as 43K. This provides a new material base for studying the origin of high-temperature superconductivity.

  6. 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.

  7. High spin states in 143Sm

    International Nuclear Information System (INIS)

    Raut, R.; Ganguly, S.; Kshetri, R.; Mukherjee, G.; Mukherjee, A.; Banerjee, P.; Saha Sarkar, M.; Bhattacharya, S.; Goswami, A.; Bhattacharjee, T.; Basu, S.K.; Mukhopadhyaya, S.; Krishichayan; Chakraborty, A.; Gangopadhyay, G.

    2004-01-01

    Large amount of experimental data has been obtained in the recent past on several Nd (Z=60) and Pm (Z=61) isotopes near N=82 shell closure which exhibits an irregular yrast sequence, typical of a non-spherical shape at low spins. The nucleus 143 Sm (Z=62) with a single neutron hole in the N=82 closed shell was investigated as a part of this proposed study

  8. Model SM-1 ballast density gauge

    International Nuclear Information System (INIS)

    Gao Weixiang; Fang Jidong; Zhang Xuejuan; Zhang Reilin; Gao Wanshan

    1990-05-01

    The ballast density is one of the principal parameters for roadbed operating state. It greatly affects the railroad stability, the accumulation of railroad residual deformation and the amount of work for railroad maintenance. SM-1 ballast density gauge is designed to determine the density of ballast by using the effect of γ-ray passed through the ballast. Its fundamentals, construction, specifications, application and economic profit are described

  9. 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.

  10. A superdeformed band in {sup 142}Sm

    Energy Technology Data Exchange (ETDEWEB)

    Hackman, G; Mullins, J M; Kuehner, J A; Prevost, D; Waddington, J C [McMaster Univ., Hamilton, ON (Canada). Dept. of Physics; Galindo-Uribarri, A; Janzen, V P; Radford, D C; Schmeing, N; Ward, D [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

    1992-08-01

    Observation of {gamma}-{gamma} coincidences from the reaction {sup 124}Sn({sup 24}Mg,6n){sup 142}Sm at 145 MeV indicates the existence of a rotational band with dynamic moment of inertia J{sup (2)} similar to that of the superdeformed band in the isotone {sup 143}Eu. This result is consistent with calculations predicting superdeformed structures in N = 80, Z {approx} 64 nuclei. (author). 8 refs., 4 figs.

  11. Ordered perovskites with cationic vacancies. 9. Compounds of the type Sr/sub 2/Srsub(1/4)Bsub(1/2)sup(III)vacantsub(1/4)WO/sub 6/ equivalent to Sr/sub 8/SrB/sub 2/sup(III)vacantW/sub 4/O/sub 24/ (Bsup(III) = La, Pr, Nd, Sm - Tm, Y)

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S; Ehmann, A [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1981-08-01

    The compounds Sr/sub 2/Srsub(1/4)Bsub(1/2)sup(III)vacantsub(1/4)WO/sub 6/ equivalent to Sr/sub 8/SrB/sub 2/sup(III)vacantW/sub 4/O/sub 24/ belong to the group of perovskites with octahedral cationic vacancies (cation/vacancy ratio (CN 6) = 7:1). For the larger Bsup(III) ions (La, Pr, Nd, Sm-Dy) different ordering effects are observed. The perovskites with Bsup(III) = Sm, Eu, Gd are polymorphic too (HT modification: higher ordered cubic perovskite (Bsup(III) = Gd: a = 2 x 8.23/sub 4/ A); LT modification: hexagonal perovskite stacking polytype (Bsup(III) = Gd: a = 9.95/sub 4/ A; c = 19.0/sub 4/ A)). With the smaller Bsup(III) ions (Ho, Er, Tm and Y) a cubic, 1:1 ordered perovskite type is observed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  13. 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

  14. Electronic and Ionic Transport in Ce0.8PrxTb0.2−xO2−δ and Evaluation of Performance as Oxygen Permeation Membranes

    DEFF Research Database (Denmark)

    Chatzichristodoulou, Christodoulos; Hendriksen, Peter Vang

    2012-01-01

    to that of Ce0.9Gd0.1O1.95−δ, and was found to increase with increasing Pr/Tb ratio. The oxide ion mobility in Ce0.8PrxTb0.2−xO2−δ is similar to that in Ce1−2δGd2δO2−δ at the same oxygen vacancy concentration. Based on the measured ionic and electronic conductivities, fluxes through thin film Ce0.8PrxTb0.2−xO2......The electronic conductivity of Ce0.8PrxTb0.2−xO2−δ (x = 0, 0.05, 0.10, 0.15, 0.20) was determined in the oxygen activity range aO2 ≈ 103 – 10−17 at 700–900°C by Hebb-Wagner polarization. The electronic conductivity of all the Ce0.8PrxTb0.2−xO2−δ compositions was significantly enhanced as compared......−δ membranes were calculated. Calculated fluxes exceed 10 Nml min−1 cm−2 under oxyfuel relevant conditions (T = 800°C, aO2,permeate side = 10−3). Hence, in terms of transport properties, these materials are promising for this application. Interference between the ionic and electronic flows has...

  15. 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.

  16. The role of antiretroviral therapy in reducing TB incidence and mortality in high HIV-TB burden countries

    Directory of Open Access Journals (Sweden)

    Anthony D Harries

    2016-03-01

    Full Text Available With the adoption of the new Sustainable Development Goals in 2016, all countries have committed to end the tuberculosis (TB epidemic by 2030, defined as dramatic reductions in TB incidence and mortality combined with zero TB-induced catastrophic costs for families. This paper explores how antiretroviral therapy (ART in high HIV-TB burden countries may help in reducing TB incidence and mortality and thus contribute to the ambitious goal of ending TB. ART in people living with HIV has a potent TB preventive effect, with this being most apparent in those with the most advanced immunodeficiency. Early ART also significantly reduces the risk of TB, and with new World Health Organization guidance released in 2015 about initiating ART in all persons living with HIV irrespective of CD4 count, there is the potential for enormous benefit at the population level. Already, several countries with high HIVTB burdens have seen dramatic declines in TB case notification rates since ART scale up started in 2004. In patients already diagnosed with HIV-associated TB, mortality can be significantly decreased by ART, especially if started within 2–8 weeks of anti-TB treatment. The benefits of ART on TB incidence and TB mortality can be further augmented respectively by the addition of isoniazid preventive therapy and cotrimoxazole preventive therapy. These interventions must be effectively implemented and scaled up in order to end the TB epidemic by 2030.

  17. 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.

  18. Magnetic properties of TbTiGe

    International Nuclear Information System (INIS)

    Prokes, K.; Tegus, O.; Brueck, E.; Gortenmulder, T.J.; Boer, F.R. de; Buschow, K.H.J.

    2001-01-01

    We have studied the magnetic properties of the compound TbTiGe by means of neutron diffraction in the temperature range 1.7-310 K. We also report on magnetization measurements made at different temperatures and fields. The compound TbTiGe adopts the tetragonal CeFeSi-structure type and orders antiferromagnetically at T N =286 K. The structure is collinear antiferromagnetic in the whole temperature range below T N , with the magnetic moments aligned along the tetragonal c-axis. The uncommon shape of the temperature dependence of the magnetization observed in our sample is attributed to small amounts of the ferromagnetic low-temperature modification of TbTiGe

  19. Study of fuel element characteristic of SM and SMP (SM-PRIMA) fuel assemblies

    International Nuclear Information System (INIS)

    Klinov, A.V.; Kuprienko, V.A.; Lebedev, V.A.; Makhin, V.M.; Tuchnin, L.M.; Tsykanov, V.A.

    1999-01-01

    The paper discusses the techniques and results of reactor tests and post-reactor investigations of the SM reactor fuel elements and fuel elements developed in the process of designing the specialized PRIMA test reactor with the SM reactor fuel elements used as a prototype and which are referred to as the SMP fuel elements. The behavior of fuel elements under normal operating conditions and under deviation from normal operating conditions was studied to verify the calculation techniques, to check the calculation results during preparation of the SM reactor safety substantiation report and to estimate the possibility of using such fuel elements in other projects. During tests of fuel rods under deviation from normal operating conditions their advantages were shown over fuel elements, the components of which were produced using the Al-based alloys. (author)

  20. TB case detection in Tajikistan – analysis of existing obstacles

    Directory of Open Access Journals (Sweden)

    Alexei Korobitsyn

    2013-10-01

    Full Text Available Background: Tajikistan National TB Control ProgramObjective: (1 To identify the main obstacles to increasing TB Detection in Tajikistan. (2 To identify interventions that improve TB detection.Methods: Review of the available original research data, health normative base, health systems performance and national economic data, following WHO framework for detection of TB cases, which is based on three scenarios of why incident cases of TB may not be notified.Results: Data analysis revealed that some aspects of TB case detection are more problematic than others and that there are gaps in the knowledge of specific obstacles to TB case detection. The phenomenon of “initial default” in Tajikistan has been documented; however, it needs to be studied further. The laboratory services detect infectious TB cases effectively; however, referrals of appropriate suspects for TB diagnosis may lag behind. The knowledge about TB in the general population has improved. Yet, the problem of TB related stigma persists, thus being an obstacle for effective TB detection. High economic cost of health services driven by under-the-table payments was identified as another barrier for access to health services.Conclusion: Health system strengthening should become a primary intervention to improve case detection in Tajikistan. More research on reasons contributing to the failure to register TB cases, as well as factors underlying stigma is needed.

  1. Acute toxicity of injection of 153Sm-EDTMP

    International Nuclear Information System (INIS)

    Chen Baiwei; Chai Xuehong

    2004-01-01

    Sm-153 has several distinct advantages as a radiopharmaceutical for the treat of patients with bone to skeletal metastasis. Sm-153 shows high skeletal uptake and rapid blood and nonosseous tissue clearance. Several paper have considered the toxicity of 153Sm-EDTMP. We report the acute toxicity in mice and rats after injection of 153Sm-EDTMP or unlabeled EDTMP. The EDTMP was injected to mice by 9.76, 7.8, 6.25, 5, 4 mg/Kg. The logarithmic dose of EDTMP were given to mice to determine LD50. The LD50 of EDTMP in mice is 7.1 mg/Kg. The decay of 153Sm-EDTMP for 4 months were injected to mice at dose of 225 mg/Kg. 153Sm-EDTMP were given at 4 difference dosage to rats by 74 MBq/Kg, 370 MBq/Kg, 1110 MBq/Kg, 1850 MBq/Kg. The LD50 of 153Sm-EDTMP in rats is more than 370 MBq/Kg. Although the cold EDTMP LD50 was low, chelated with Sm can decrease it's toxicity. The decay 153Sm-EDTMP can be safe at dose of 225 mg/Kg. The clinical dose will be used at 37 MBq/Kg. So there is no need to consider to acute toxicity in clinical used 153Sm-EDTMP in designated regimen because the safe range is wide enough to cover clinical used. (authors)

  2. Dielectric spectroscopy of the SmQ* phase

    Science.gov (United States)

    Perkowski, P.; Bubnov, A.; Piecek, W.; Ogrodnik, K.; Hamplová, V.; Kašpar, M.

    2011-11-01

    Liquid crystal possessing two biphenyl moieties in the molecular core and lateral chlorine substitution far from the chiral chain has been studied by dielectric spectroscopy. On cooling from the isotropic phase, the material possesses the frustrated smectic Q* (SmQ*) and SmCA* phases. It has been confirmed by dielectric spectroscopy that the SmQ* phase can be related to the SmCA* anti-ferroelectric phase. However, only one relaxation process has been observed in the SmQ* phase, while in the SmCA*, two relaxations are clearly detectable. It seems that the mode found in the SmQ* can be connected with high-frequency anti-phase mode observed in the SmCA* phase. Its relaxation frequency is similar to PH relaxation frequency, but is weaker. The same relaxation has been observed even a few degrees above the SmQ*-Iso phase transition. Another explanation for the mode detected in SmQ* and isotropic phases can be molecular motions around short molecular axis.

  3. 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_xO_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.

  4. Tuberculosis: The Connection between TB and HIV (the AIDS Virus)

    Science.gov (United States)

    ... Regimen for Latent TB Infection-Patient Education Brochure Posters Mantoux Tuberculin Skin Test Wall Chart World TB ... site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel file Audio/Video file Apple ...

  5. Combination of TB lymphadenitis and metastatic LAP in breast cancer

    Directory of Open Access Journals (Sweden)

    Abdolhassan Talaiezadeh

    2015-06-01

    Full Text Available Tuberculosis (TB may present as pulmonary and extra-pulmonary. TB lymphadenitis is the most common presentation of extra-pulmonary TB. TB lymphadenitis should be taken into account in the differential diagnosis of different disorders such as metastatic lymphadenopathy. The reported patient was a 65-year-old lady with breast cancer and conglomerated and matted axillary lymphadenopathy who received chemotherapy. She presented with more extensive axillary LAP contrary to our expectation. Modified radical mastectomy was done and pathology analysis reported TB lymphadenitis associated with metastatic LAP. Under cover of anti-TB therapy adjuvant chemoradiation therapy was started. Accordingly, we recommend TB be ruled out in every patient who needs chemotherapy in the endemic region because chemotherapy may cause the extension of TB in the body.

  6. Patient satisfaction with TB care clinical consultations in Kampala: a ...

    African Journals Online (AJOL)

    ... on treatment outcome. Keywords: Patient satisfaction, TB care clinical consultations, cross sectional study. ... Background: Tuberculosis (TB) remains a major global ... Measurement of outcome: Variables considered were; how long the ... Key: ART= Antiretroviral Therapy. Characteristic. Parameter n (%). Sex. Female.

  7. Tuberculosis: Learn the Signs and Symptoms of TB Disease

    Science.gov (United States)

    ... this? Submit What's this? Submit Button Past Emails Tuberculosis (TB) Disease: Symptoms and Risk Factors Language: English ( ... Español (Spanish) Recommend on Facebook Tweet Share Compartir Tuberculosis (TB) is a disease caused by bacteria that ...

  8. Luminescence properties of the Sm-doped borate glasses

    International Nuclear Information System (INIS)

    Kindrat, I.I.; Padlyak, B.V.; Drzewiecki, A.

    2015-01-01

    The optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Sm-doped glasses with Li 2 B 4 O 7 , LiKB 4 O 7 , CaB 4 O 7 , and LiCaBO 3 compositions were investigated and analysed. The Li 2 B 4 O 7 :Sm, LiKB 4 O 7 :Sm, CaB 4 O 7 :Sm, and LiCaBO 3 :Sm glasses of high optical quality have been obtained from the corresponding polycrystalline compounds in the air atmosphere, using a standard glass technology. On the basis of electron paramagnetic resonance (EPR) and optical spectra analysis it was shown that the samarium impurity is incorporated into the glass network as Sm 3+ (4f 5 , 6 H 5/2 ) ions, exclusively. All observed 4f – 4f transitions of the Sm 3+ centres in the optical absorption and luminescence spectra of the investigated glasses are identified. Most intense emission band of the Sm 3+ ions peaked about 598 nm ( 4 G 5/2 → 6 H 7/2 transition) is characterised by a single exponential decay with typical lifetime values, which depend on the basic glass composition as well as concentration and local structure of the Sm 3+ luminescence centres. The quantum efficiency has been evaluated for observed transitions of the Sm 3+ centres using obtained experimental lifetimes and radiative lifetimes calculated by Judd–Ofelt theory. The calculated high quantum efficiencies and measured quantum yields of luminescence show that the investigated borate glasses are perspective luminescence materials. Energy transfer from the Ce 3+ non-controlled impurity and intrinsic luminescence centres to the Sm 3+ centres has been observed. Peculiarities of the Sm 3+ local structure in the network of investigated glasses have been discussed based on the obtained spectroscopic results and structural data. - Highlights: • The Sm-doped Li 2 B 4 O 7 , LiKB 4 O 7 , CaB 4 O 7 , and LiCaBO 3 glasses of high quality were obtained. • EPR, optical absorption and luminescence spectra of Sm 3+ ions in obtained glasses were

  9. 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.

  10. Comparison of PPD test in household contacts of smear-positive and -negative tuberculosis (TB

    Directory of Open Access Journals (Sweden)

    Zohreh Azarkar

    2015-01-01

    Conclusions: The most important way to prevent TB is omission of the disease transmission sources (TB patients by anti-TB treatment. Extensive studies are needed to ensure that contacts of patients with pulmonary TB are identified and appropriately screened.

  11. Exploring workplace TB interventions with foreign-born Latino workers.

    Science.gov (United States)

    Eggerth, Donald E; Keller, Brenna M; Flynn, Michael A

    2018-05-15

    Persons born outside the United States are more likely to be diagnosed with tuberculosis disease (TB) than native-born individuals. Foreign-born Latinos at risk of TB may be difficult to reach with public health interventions due to cultural and institutional barriers. Workplaces employing large concentrations of foreign-born Latinos may be useful locations for TB interventions targeting this high-risk population. This study used a two-phase approach to investigate the feasibility of workplace TB interventions. The first phase investigated employer knowledge of TB and receptiveness to allowing TB interventions in their businesses through 5 structured interviews. The second phase investigated foreign-born workers' knowledge of TB and their receptiveness to receiving TB interventions in their places of employment through 12 focus groups stratified by gender and education. Phase 1: Only 1 of the 5 employers interviewed had a high level of knowledge about TB, and three had no knowledge other than that TB was a disease that involved coughing. They were receptive to workplace TB interventions, but were concerned about lost productivity and customers finding out if an employee had TB. Phase 2: There was no observed differences in responses between gender and between the bottom two education groups, so the final analysis took place between a gender-combined lower education group and higher education group. The higher education group tended to have knowledge that was more accurate and to view TB as a disease associated with poverty. The lower education group tended to have more misconceptions about TB and more often expressed concern that their employers would not support worksite interventions. The results from both phases indicate that more TB education is needed among both foreign-born Latino workers and their employers. Obstacles to implementing workplace TB interventions include knowledge, potential productivity loss, employer liability, and perceived customer response

  12. Diagnosis of active TB using aptamers

    CSIR Research Space (South Africa)

    Khati, M

    2013-08-01

    Full Text Available of the disease. We have shown in a proof-of-concept case-controlled study that the aptamer-based diagnostic tool was able to accurately detect all cases of active TB from sputum samples of patients, including smear-negative culture positive and samples from...

  13. 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)

  14. Effect of Al{sub 2}Gd on microstructure and properties of laser clad Mg–Al–Gd coatings

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong; Zhang, Ke; Yao, Chengwu [Shanghai Key Lab of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Dong, Jie [National Engineering Research Center of Light Alloy Net Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Li, Zhuguo, E-mail: lizg@sjtu.edu.cn [Shanghai Key Lab of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Emmelmann, Claus [Institute of Laser and System Technologies, Hamburg University of Technology, Hamburg, 21073 (Germany)

    2015-03-01

    Highlights: • Mg–Al–Gd coatings with different Gd contents were fabricated by fiber laser cladding. • Chemical compositions and crystal structures of the second phases were characterized. • Dispersion of Al{sub 2}Gd led to further grain refining and elevated mechanical properties. • Al{sub 2}Gd improved high-temperature performances by preventing tiny liquation. - Abstract: In order to investigate the effects of Gd addition on the microstructures and properties of magnesium coatings, the Mg–7.5Al–xGd (x = 0, 2.5, 5.0 and 7.5 wt.%) coatings on cast magnesium alloy were fabricated by laser cladding with wire feeding. The results indicated that the gadolinium (Gd) addition led to the formation of a cubic Al{sub 2}Gd phase as well as suppressed the precipitation of eutectic Mg{sub 17}Al{sub 12} phase. The laser clad coating containing nominally 7.5 wt.% Gd presented the highest microhardness, ultimate tensile strength and yield strength at both room temperature and high temperatures. The enhancement of heat resistant capacities was chiefly attributed to the existence of thermally stable Al{sub 2}Gd particles, which prevented tiny liquation of eutectic phases along the grain boundaries and made great contributions on maintaining high yield ratio during high-temperature deformation.

  15. Effect of Al2Gd on microstructure and properties of laser clad Mg–Al–Gd coatings

    International Nuclear Information System (INIS)

    Chen, Hong; Zhang, Ke; Yao, Chengwu; Dong, Jie; Li, Zhuguo; Emmelmann, Claus

    2015-01-01

    Highlights: • Mg–Al–Gd coatings with different Gd contents were fabricated by fiber laser cladding. • Chemical compositions and crystal structures of the second phases were characterized. • Dispersion of Al 2 Gd led to further grain refining and elevated mechanical properties. • Al 2 Gd improved high-temperature performances by preventing tiny liquation. - Abstract: In order to investigate the effects of Gd addition on the microstructures and properties of magnesium coatings, the Mg–7.5Al–xGd (x = 0, 2.5, 5.0 and 7.5 wt.%) coatings on cast magnesium alloy were fabricated by laser cladding with wire feeding. The results indicated that the gadolinium (Gd) addition led to the formation of a cubic Al 2 Gd phase as well as suppressed the precipitation of eutectic Mg 17 Al 12 phase. The laser clad coating containing nominally 7.5 wt.% Gd presented the highest microhardness, ultimate tensile strength and yield strength at both room temperature and high temperatures. The enhancement of heat resistant capacities was chiefly attributed to the existence of thermally stable Al 2 Gd particles, which prevented tiny liquation of eutectic phases along the grain boundaries and made great contributions on maintaining high yield ratio during high-temperature deformation

  16. 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

  17. Antiretroviral treatment uptake in patients with HIV- associated TB ...

    African Journals Online (AJOL)

    ART results in a 64 - 95% reduction in mortality risk 5 and is an essential component of care. How soon to start. ART after TB treatment initiation has become clearer from randomised controlled trials. These show that integration of ART and TB treatment in all HIV-associated TB patients regardless of CD4 count significantly.

  18. Assessment of the Diagnostic Potential of Clinotech TB Screen Test ...

    African Journals Online (AJOL)

    The Clinotech TB Screen test, a 3rd generation multi-antigen rapid chromatographic immunoassay for detection of IgG antibodies in serum against recombinant protein antigens 38kDa, 16kDa and 6kDa, was assessed for its diagnostic potential for diagnosis of active pulmonary TB in routine TB control programme in Abia ...

  19. Antiretroviral treatment uptake in patients with HIV associated TB ...

    African Journals Online (AJOL)

    Background. Delivery of integrated care for patients with HIV-associated TB is challenging. We assessed the uptake and timing of antiretroviral treatment (ART) among eligible patients attending a primary care service with co-located ART and TB clinics. Methods. In a retrospective cohort study, all HIV-associated TB patients ...

  20. 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.

  1. Heat capacity and magnetocaloric effect in polycrystalline Gd 1-xSm xMn 2Si 2

    Science.gov (United States)

    Kumar, Pramod; Singh, Niraj K.; Suresh, K. G.; Nigam, A. K.; Malik, S. K.

    2007-12-01

    We report the magnetocaloric effect in terms of isothermal magnetic entropy change as well as adiabatic temperature change, calculated using the heat capacity data. Using the zero-field heat capacity data, the magnetic contribution to the heat capacity has been estimated. The variations in the magnetocaloric behavior have been explained on the basis of the magnetic structure of these compounds. The refrigerant capacities have also been calculated for these compounds.

  2. Thermal expansion and conductivity of RE2Sn2O7 (RE = La, Nd, Sm, Gd, Er and Yb) pyrochlores

    International Nuclear Information System (INIS)

    Feng, J.; Xiao, B.; Zhou, R.; Pan, W.

    2013-01-01

    Graphical abstract: Calculated cohesive energies and formation enthalpies of RE 2 Sn 2 O 7 compounds. The formation enthalpies at 298 K are more close to the experimental values. -- The calculated cohesive energies and formation enthalpies of Rare earth stannate (RE 2 Sn 2 O 7 ) compounds are in good agreement with the corresponding experimental values. The thermal expansion coefficients (TECs) of rare earth stannates are 7–9 × 10 −6 K −1 at high temperature. The results show that local spin density approximation predicts smaller TECs than the real values. The computed thermal conductivity of RE 2 Sn 2 O 7 is 1.8–2.5 W (m · K) −1 at 1273 K using the Slack–Clarke model, indicating that RE 2 Sn 2 O 7 compounds exhibit good thermal insulating properties at high temperature

  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. Level Lifetime Measurements in ^150Sm

    Science.gov (United States)

    Barton, C. J.; Krücken, R.; Beausang, C. W.; Caprio, M. A.; Casten, R. F.; Cooper, J. R.; Hecht, A. A.; Newman, H.; Novak, J. R.; Pietralla, N.; Wolf, A.; Zyromski, K. E.; Zamfir, N. V.; Börner, H. G.

    2000-10-01

    Shape/phase coexistence and the evolution of structure in the region around ^152Sm have recently been of great interest. Experiments performed at WNSL, Yale University, measured the lifetime of low spin states in a target of ^150Sm with the recoil distance method (RDM) and the Doppler-shift attenuation method (DSAM). The low spin states, both yrast and non-yrast, were populated via Coulomb excitation with a beam of ^16O. The experiments were performed with the NYPD plunger in conjunction with the SPEEDY γ-ray array. The SCARY array of solar cells was used to detect backward scattered projectiles, selecting forward flying Coulomb excited target nuclei. The measured lifetimes yield, for example, B(E2) values for transitions such as the 2^+2 arrow 2^+1 and the 2^+3 arrow 0^+_1. Data from the RDM measurment and the DSAM experiment will be presented. This work was supported by the US DOE under grants DE-FG02-91ER-40609 and DE-FG02-88ER-40417.

  5. Magnetic properties of Sm-based filled skutterudite phosphides

    Energy Technology Data Exchange (ETDEWEB)

    Giri, R.; Sekine, C.; Shimaya, Y.; Shirotani, I.; Matsuhira, K.; Doi, Y.; Hinatsu, Y.; Yokoyama, M.; Amitsuka, H

    2003-05-01

    Filled skutterudites SmFe{sub 4}P{sub 12} and SmOs{sub 4}P{sub 12} have been prepared at high temperature and high pressure. The temperature dependence of electrical resistivity in both compounds shows metallic behavior. The magnetic susceptibility and specific heat measurements indicate that SmFe{sub 4}P{sub 12} shows a ferromagnetic ordering at 1.5 K, whereas SmOs{sub 4}P{sub 12} is an antiferromagnet with a T{sub N} of 4.6 K.

  6. Anomalous Hall effect in Fe/Gd bilayers

    KAUST Repository

    Xu, W. J.; Zhang, Bei; Liu, Z. X.; Wang, Z.; Li, W.; Wu, Z. B.; Yu, R. H.; Zhang, Xixiang

    2010-01-01

    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

  7. 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

  8. Evaluation of the exothermicity of the chemi-ionization reaction Sm + O → SmO+ + e−

    International Nuclear Information System (INIS)

    Cox, Richard M; Kim, JungSoo; Armentrout, P. B.; Bartlett, Joshua; VanGundy, Robert A.; Heaven, Michael C.; Ard, Shaun G.; Shuman, Nicholas S.; Viggiano, Albert A.; Melko, Joshua J.

    2015-01-01

    The exothermicity of the chemi-ionization reaction Sm + O → SmO + + e − has been re-evaluated through the combination of several experimental methods. The thermal reactivity (300–650 K) of Sm + and SmO + with a range of species measured using a selected ion flow tube-mass spectrometer apparatus is reported and provides limits for the bond strength of SmO + , 5.661 eV ≤ D 0 (Sm + -O) ≤ 6.500 eV. A more precise value is measured to be 5.72 5 ± 0.07 eV, bracketed by the observed reactivity of Sm + and SmO + with several species using a guided ion beam tandem mass spectrometer (GIBMS). Combined with the established Sm ionization energy (IE), this value indicates an exothermicity of the title reaction of 0.08 ± 0.07 eV, ∼0.2 eV smaller than previous determinations. In addition, the ionization energy of SmO has been measured by resonantly enhanced two-photon ionization and pulsed-field ionization zero kinetic energy photoelectron spectroscopy to be 5.7427 ± 0.0006 eV, significantly higher than the literature value. Combined with literature bond energies of SmO, this value indicates an exothermicity of the title reaction of 0.14 ± 0.17 eV, independent from and in agreement with the GIBMS result presented here. The evaluated thermochemistry also suggests that D 0 (SmO) = 5.83 ± 0.07 eV, consistent with but more precise than the literature values. Implications of these results for interpretation of chemical release experiments in the thermosphere are discussed

  9. Phase-Transition and Magnetic Moment of the Gd3+ Ion in the Gd2Fe17 Compound

    Institute of Scientific and Technical Information of China (English)

    HAO Yan-Ming; FU Bin; ZHOU Yan; ZHAO Miao

    2009-01-01

    The structure and magnetic phase transitions of the Gd2Fe17 compound are investigated by using a differential thermal/thermogravimetric analyzer, x-ray diffraction, and magnetization measurements. The result shows that there are two phase structures for the Gd2Fe17 compound: the hexagonal Th2Ni17-type structure at high tem-peratures (above 1243℃), and the rhombohedrai Th2Zn17-type structure, respectively. A method to measure the magnetic moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound is presented. The moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound from 77 to 500 K are measured in this way with a vibrating sample magnetometer. A detailed discussion is presented.

  10. SmBaCoCuO5+x as cathode material based on GDC electrolyte for intermediate-temperature solid oxide fuel cells

    International Nuclear Information System (INIS)

    Lue Shiquan; Long, Guohui; Ji Yuan; Meng Xiangwei; Zhao Hongyuan; Sun Cuicui

    2011-01-01

    Research highlights: → We synthesize a new kind of layered perovskite SmBaCoCuO 5+x (SBCCO) as a cathode material of a solid oxide fuel cell. → There are some reports on the performance of cathodes in proton-conducting SOFCs based on BaCe 0.8 Sm 0.2 O 3-δ electrolyte. → However, to the best of our knowledge, the performance of SBCCO cathodes in oxygen-ion conducting SOFCs has not been reported to date. → In this work, the ceramic powder SBCCO is examined as a cathode for IT-SOFCs based on Ce 0.9 Gd 0.1 O 1.95 (GDC) electrolyte. - Abstract: The performance of SmBaCoCuO 5+x (SBCCO) cathode has been investigated for their potential utilization in intermediate-temperature solid oxide fuel cells (IT-SOFCs). The powder X-ray diffraction (XRD), thermal expansion and electrochemical performance on Ce 0.9 Gd 0.1 O 1.95 (GDC) electrolyte are evaluated. XRD results show that there is no chemical reaction between SBCCO cathode and GDC electrolyte when the temperature is below 950 o C. The thermal expansion coefficient (TEC) value of SBCCO is 15.53 x 10 -6 K -1 , which is ∼23% lower than the TEC of the SmBaCo 2 O 5+x (SBCO) sample. The electrochemical impedance spectra reveals that SBCCO symmetrical half-cells by sintering at 950 deg. C has the best electrochemical performance and the area specific resistance (ASR) of SBCCO cathode is as low as 0.086 Ω cm 2 at 800 o C. An electrolyte-supported fuel cell generates good performance with the maximum power density of 517 mW cm -2 at 800 deg. C in H 2 . Preliminary results indicate that SBCCO is promising as a cathode for IT-SOFCs.

  11. TIME Impact - a new user-friendly tuberculosis (TB) model to inform TB policy decisions.

    Science.gov (United States)

    Houben, R M G J; Lalli, M; Sumner, T; Hamilton, M; Pedrazzoli, D; Bonsu, F; Hippner, P; Pillay, Y; Kimerling, M; Ahmedov, S; Pretorius, C; White, R G

    2016-03-24

    Tuberculosis (TB) is the leading cause of death from infectious disease worldwide, predominantly affecting low- and middle-income countries (LMICs), where resources are limited. As such, countries need to be able to choose the most efficient interventions for their respective setting. Mathematical models can be valuable tools to inform rational policy decisions and improve resource allocation, but are often unavailable or inaccessible for LMICs, particularly in TB. We developed TIME Impact, a user-friendly TB model that enables local capacity building and strengthens country-specific policy discussions to inform support funding applications at the (sub-)national level (e.g. Ministry of Finance) or to international donors (e.g. the Global Fund to Fight AIDS, Tuberculosis and Malaria).TIME Impact is an epidemiological transmission model nested in TIME, a set of TB modelling tools available for free download within the widely-used Spectrum software. The TIME Impact model reflects key aspects of the natural history of TB, with additional structure for HIV/ART, drug resistance, treatment history and age. TIME Impact enables national TB programmes (NTPs) and other TB policymakers to better understand their own TB epidemic, plan their response, apply for funding and evaluate the implementation of the response.The explicit aim of TIME Impact's user-friendly interface is to enable training of local and international TB experts towards independent use. During application of TIME Impact, close involvement of the NTPs and other local partners also builds critical understanding of the modelling methods, assumptions and limitations inherent to modelling. This is essential to generate broad country-level ownership of the modelling data inputs and results. In turn, it stimulates discussions and a review of the current evidence and assumptions, strengthening the decision-making process in general.TIME Impact has been effectively applied in a variety of settings. In South Africa, it

  12. Obstructive lung disease as a complication in post pulmonary TB

    Science.gov (United States)

    Tarigan, A. P.; Pandia, P.; Eyanoer, P.; Tina, D.; Pratama, R.; Fresia, A.; Tamara; Silvanna

    2018-03-01

    The case of post TB is a problem that arises in the community. Pulmonary tuberculosis (TB) can affect lung function. Therefore, we evaluated impaired pulmonary function in subjects with diagnosed prior pulmonary TB. A Case Series study, pulmonary function test was performed in subjects with a history of pulmonary tuberculosis; aged ≥18 years were included. Exclusion criteria was a subject who had asthma, obesity, abnormal thorax and smoking history. We measured FEV1 and FVC to evaluate pulmonary function. Airflow obstruction was FEV1/FVC%pulmonary TB, 5 subjects (23%) had airflow obstruction with FEV1/FVC% value pulmonary TB.

  13. 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

    When the model dosimetry system YPO4: Ce3+, Sm3+ is exposed to X-rays, the charge state of the dopants changes, becoming Ce4+ and Sm2+ via hole and electron trapping, respectively which are metastable; the original charge states can be achieved through electron transfer back from Sm2+ to Ce4+ via......) and its temperature dependence to provide insights into thermal quenching, and c) the kinetics of localised recombination from Sm2+ to Ce4+ on nanoseconds to seconds time scales using sub-band-edge excitation....

  14. Magnetocaloric effect and transport properties of Gd5Ge2(Si1-x Sn x )2 (x=0.23 and 0.40) compounds

    International Nuclear Information System (INIS)

    Campoy, J.C.P.; Plaza, E.J.R.; Nascimento, F.C.; Coelho, A.A.; Pereira, M.C.; Fabris, J.D.; Raposo, M.T.; Cardoso, L.P.; Persiano, A.I.C.; Gama, S.

    2007-01-01

    We report a study about the structural properties of polycrystalline samples of nominal composition Gd 5 Ge 2 (Si 1- x Sn x ) 2 (x=0.23, 0.40) that closely influence their physical behavior particularly related to electric resistivity and magnetocaloric (MCE) effect. The samples were characterized by X-ray diffraction (XRD) using the Rietveld refinement method, metallographic analyses, 119 Sn Moessbauer spectroscopy, DC magnetization and electrical transport measurements. It was identified a Gd 5 Si 2 Ge 2 -monoclinic phase for x=0.23 and a Sm 5 Sn 4 -orthorhombic phase (type II) for x=0.40, both with two non-equivalent crystallographic sites for the Sn ions. We were able to infer on the role of tin on the magnetic and transport properties in these compounds

  15. Technology and tuberculosis control: the OUT-TB Web experience.

    Science.gov (United States)

    Guthrie, Jennifer L; Alexander, David C; Marchand-Austin, Alex; Lam, Karen; Whelan, Michael; Lee, Brenda; Furness, Colin; Rea, Elizabeth; Stuart, Rebecca; Lechner, Julia; Varia, Monali; McLean, Jennifer; Jamieson, Frances B

    2017-04-01

    Develop a tool to disseminate integrated laboratory, clinical, and demographic case data necessary for improved contact tracing and outbreak detection of tuberculosis (TB). In 2007, the Public Health Ontario Laboratories implemented a universal genotyping program to monitor the spread of TB strains within Ontario. Ontario Universal Typing of TB (OUT-TB) Web utilizes geographic information system (GIS) technology with a relational database platform, allowing TB control staff to visualize genotyping matches and microbiological data within the context of relevant epidemiological and demographic data. OUT-TB Web is currently available to the 8 health units responsible for >85% of Ontario's TB cases and is a valuable tool for TB case investigation. Users identified key features to implement for application enhancements, including an e-mail alert function, customizable heat maps for visualizing TB and drug-resistant cases, socioeconomic map layers, a dashboard providing TB surveillance metrics, and a feature for animating the geographic spread of strains over time. OUT-TB Web has proven to be an award-winning application and a useful tool. Developed and enhanced using regular user feedback, future versions will include additional data sources, enhanced map and line-list filter capabilities, and development of a mobile app. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  16. Lay beliefs of TB and TB/HIV co-infection in Addis Ababa, Ethiopia: a qualitative study

    Directory of Open Access Journals (Sweden)

    Frich Jan C

    2011-08-01

    Full Text Available Abstract Background Knowledge about lay beliefs of etiology, transmission and treatment of TB, and lay perceptions of the relationship between TB and HIV is important for understanding patients' health seeking behavior and adherence to treatment. We conducted a study to explore lay beliefs about TB and TB/HIV co-infection in Addis Ababa, Ethiopia. Findings We conducted a qualitative study using in-depth interviews with 15 TB/HIV co-infected patients and 9 health professionals and focus group discussions with 14 co-infected patients in Addis-Ababa, Ethiopia. We found that a predominant lay belief was that TB was caused by exposure to cold. Excessive sun exposure, exposure to mud, smoking, alcohol, khat and inadequate food intake were also reported as causes for TB. Such beliefs initially led to self-treatment. The majority of patients were aware of an association between TB and HIV. Some reported that TB could transform into HIV, while others said that the body could be weakened by HIV and become more susceptible to illnesses such as TB. Some patients classified TB as either HIV-related or non-HIV-related, and weight loss was a hallmark for HIV-related TB. The majority of patients believed that people in the community knew that there was an association between TB and HIV, and some feared that this would predispose them to HIV-related stigma. Conclusion There is a need for culturally sensitive information and educational efforts to address misperceptions about TB and HIV. Health professionals should provide information about causes and treatment of TB and HIV to co-infected patients.

  17. A comparison of Gd-BOPTA and Gd-DOTA for contrast-enhanced MRI of intracranial tumours

    International Nuclear Information System (INIS)

    Colosimo, C.; Knopp, M.V.; Barreau, X.; Gerardin, E.; Kirchin, M.A.; Guezenoc, F.; Lodemann, K.P.

    2004-01-01

    A two-centre intra-individual crossover study was performed in 23 patients with suspected high-grade glioma or metastases to assess and compare the safety and enhancement characteristics of two different MRI contrast media (gadobenate dimeglumine, Gd-BOPTA and gadoterate meglumine, Gd-DOTA) at equivalent doses of 0.1 mmol/kg body weight. T1-weighted spin-echo (SE) and T2-weighted fast SE images were obtained before and T1-weighted images 0, 2, 4, 6, 8 and 15 min after injection. T1-weighted images with magnetisation transfer contrast were acquired 12 min after injection. Qualitative assessment by blinded, off-site readers (reader 1: 19 patients; reader 2: 21) and on-site investigators (23) revealed significant (P ≤0.005) overall preference for Gd-BOPTA over Gd-DOTA for contrast enhancement (Gd-BOPTA preferred in 18, 15 and 18 cases; Gd-DOTA in 0, 1 and 1 and no preference in 1, 5 and 4; off-site readers 1 and 2, and on-site investigators, respectively). A similar significant preference for Gd-BOPTA was expressed by off-site readers and on-site investigators for lesion-to-brain contrast, lesion delineation, internal lesion structure, and overall image preference. Quantitative assessment by off-site readers revealed significantly (p<0.05) greater lesion enhancement with Gd-BOPTA than with Gd-DOTA at all times from 2 min after injection. (orig.)

  18. The effect of Gd doping on the electrical and photoelectrical properties of Gd:ZnO/p-Si heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Baturay, Silan [Department of Physics, Faculty of Science, Dicle University, 21280 Diyarbakir (Turkey); Ocak, Yusuf Selim, E-mail: yusufselim@gmail.com [Department of Science, Faculty of Education, Dicle University, 21280 Diyarbakir (Turkey); Science and Technology Application and Research Center, Dicle University, 21280 Diyarbakir (Turkey); Kaya, Derya [Department of Physics, Institute of Natural Applied Sciences, Dicle University, 21280 Diyarbakir (Turkey)

    2015-10-05

    Highlights: • Undoped and Gd doped ZnO thin films were deposited onto p-Si semiconductor. • The Gd:ZnO/p-Si heterojunctions were compared with undoped ZnO/p-Si heterojunction. • A strong effect of Gd doping on the performance of the devices were reported. - Abstract: Undoped ZnO thin films, as well as 1%, 3% and 5% Gd-doped ZnO films, were deposited on p-type Si using spin coating. The structural properties of these thin films were analysed using X-ray diffraction, and the current–voltage (I–V) and capacitance–voltage (C–V) characteristics of the Gd:ZnO/p-Si heterojunctions were compared with those of the undoped ZnO/p-Si heterojunctions. We found that Gd doping had a strong effect on the performance of the devices, and that the Gd:ZnO/p-Si heterojunctions formed with 1% Gd-doped ZnO were the most strongly rectifying, and had the highest barrier height and the lowest series resistance. Furthermore, the I–V measurements of the 1% Gd-doped ZnO/p-Si heterojunction exhibited the strongest response to light.

  19. Propiedades estructurales y magnéticas de aleaciones Gd0.257 -xTbxFe0.743 obtenidas por aleamiento mecánico

    Directory of Open Access Journals (Sweden)

    Mauricio Galvis-Patiño

    2017-01-01

    Full Text Available En el presente trabajo se reporta el estudio de las propiedades estructurales y magnéticas de la composición en forma de polvo de Gd0.257-xTbxFe0.743 con x=0,  0.1285,  0.257,preparados por Aleamiento Mecánico (AM en atmosfera de argón durante 72 horas mediante un molino planetario de alta energía ;la caracterización estructural se realizó por medio de Difractometría de rayos X(DRX, para la caracterización magnética se utilizó la espectroscopía Mössbauer, los ciclos de histéresis se llevaron a cabo a través de  PPMS (Physical Property Measurement System, Sistema de Medidas de Propiedades Físicas. La fase de α-Fe se presenta en los tres difractogramas mediante un pico característico cuya  intensidad disminuye al reemplazar el Tb por el Gd, presentándose la menor en x= 0 así mismo se observa un aumento de su ancho atribuible a la presencia de átomos de Gd en lugares propios del Fe. Los espectros Mössbauer (EM fueron ajustados con sextetos, dobletes, singletes y distribuciones de campo hiperfino lo que señala que el orden magnético se ve alterado al sustituir el Tb por el Gd en la composición. Las propiedades magnéticas extrínsecas de la composición en estudio, la caracterizan como materiales magnéticamente semiduros.

  20. 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.