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Sample records for scandium yttrium lanthanide

  1. Scandium, yttrium and the lanthanides

    International Nuclear Information System (INIS)

    Hart, F.A.

    1987-01-01

    This chapter on the chemistry of the coordination complexes of scandium, yttrium and the lanthanides includes sections on the nitrogen and oxygen donor ligands and complex halides of scandium, and the phosphorus and sulfur donor ligands of yttrium and the lanthanides. Complexes with the macrocylic ligands and with halides are also discussed. Sections on the NMR and electronic spectra of the lanthanides are also included. (UK)

  2. Scandium, yttrium and the lanthanide metals

    International Nuclear Information System (INIS)

    Brown, Paul L.; Ekberg, Christian

    2016-01-01

    The hydroxide and oxide phases that exist for scandium(III) include scandium hydroxide, which likely has both amorphous and crystalline forms, ScOOH(s), and scandium oxide. This chapter presents the data selected for the stability constants of the polymeric hydrolysis species of scandium at zero ionic strength. The behaviour of yttrium, and the lanthanide metals, in the environment is largely dependent on their solution equilibria. Hydrolysis and other complexation reactions of yttrium and the lanthanide metals are important in the disposal of nuclear waste. The trivalent lanthanide metals include lanthanum(III) through lutetium(III). A number of studies have reported a tetrad effect for the geochemical behaviour of the lanthanide series, including stability constants and distribution coefficients. The solubility of many of the lanthanide hydroxide phases has been studied at fixed ionic strength. In studying the hydrolysis of cerium(IV), a number of studies have utilised oxidation-reduction reactions in determining the relevant stability constants.

  3. Trends in metallo-organic chemistry of scandium, yttrium, and the lanthanides

    International Nuclear Information System (INIS)

    Singh, A.

    1994-01-01

    Several interesting aspects of the metallo-organic chemistry of group 3 and the lanthanides have been highlighted, which include: (a) the chemistry of a few notable organolanthanide compounds, alkoxo and aryloxo derivatives derived from sterically demanding ligands, (b) new trends in the chemistry of lanthanide heterometallic alkoxides, (c) an account of zero valent organometallics of yttrium and the lanthanides, and (d) aspects of agostic interactions in the lanthanide metallo-organic compounds. (author). 49 refs

  4. Structural characteristics and physical properties of diortho(pyro)silicate crystals of lanthanides yttrium and scandium grown by the Czochralski technique

    Energy Technology Data Exchange (ETDEWEB)

    Anan' eva, G.V.; Karapetyan, V.E.; Korovkin, A.M.; Merkulyaeva, T.I.; Peschanskaya, I.A.; Savinova, I.P.; Feofilov, P.P. (Gosudarstvennyj Opticheskij Inst., Leningrad (USSR))

    1982-03-01

    Optically uniform monocrystals of diortho (pyro) silicates of lanthanides, yttrium, and scandium were grown by the Czochralski technique. Four structural types of Ln/sub 2/(Si/sub 2/O/sub 7/) crystals were determined by the roentgenographic method. The presence of structural subgroups was also supported by the method of spectroscopic probes. Structural parameters were determined and data on certain physical properties (fusion temperature, density, refractive indices, transparency) of investigated crystals were presented. The generation of induced emission at lambda=1.057 ..mu..m was obtained in La/sub 2/(Si/sub 2/O/sub 7/)-Nd/sup 3 +/ crystal.

  5. Method for chromatographically recovering scandium and yttrium

    International Nuclear Information System (INIS)

    Snyder, T.S.; Stoltz, R.A.

    1991-01-01

    This paper describes a method for chromatographically recovering scandium and yttrium from the residue of a sand chlorinator. It comprises: providing a residue from a sand chlorinator, the residue containing scandium, yttrium, sodium, calcium and at least one radioactive metal of the group consisting of radium, thorium and uranium; digesting the residue with an acid to produce an aqueous liquid containing scandium, yttrium, sodium, calcium and at least one radioactive metal of the group consisting of radium, thorium and uranium; feeding the metal containing liquid through a cation exchanger; eluding the cation exchanger with an acid eluant to to produce: a first eluate containing at least half of the total weight of the calcium and sodium in the feed liquid; a second eluate containing at least half of the total weight of the one or more radioactive metals in the feed liquid; a third eluate containing at least half of the yttrium in the feed liquid, and a fourth eluate containing at least half of the weight of the scandium in the feed liquid

  6. Study on the coextraction of scandium-yttrium-lumogallion complex

    International Nuclear Information System (INIS)

    Okada, T.; Shimoishi, Y.; Miyata, H.; Toei, K.

    1977-01-01

    The coextraction of scandium-yttrium-lumogallion [LMG;4-chloro-6-(2,4-dihydroxyphenylazo)-1-hydroxybenzene-2-sulfonic acid] into diethyl ether has been studied. The acid dissociation constants of LMG, pKsub(a2) and pKsub(a3), were estimated to be 6.24 and 8.05 respectively. The composition of the complex extracted was determined by using the radioisotopes 46 Sc and 90 Y and by spectrophotometry of LMG and the ratio of the components was Sc:Y:LMG = 1:1:3. The coextraction scheme was discussed briefly. (author)

  7. Structural differences of half-sandwich complexes of scandium and yttrium containing bulky substituents

    Czech Academy of Sciences Publication Activity Database

    Fridrichová, Adéla; Růžička, A.; Lamač, Martin; Horáček, Michal

    2017-01-01

    Roč. 76, FEB 2017 (2017), s. 62-66 ISSN 1387-7003 R&D Projects: GA ČR(CZ) GAP207/12/2368 Institutional support: RVO:61388955 Keywords : scandium * yttrium * half-sandwich Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.640, year: 2016

  8. Process for recovering yttrium and lanthanides from wet-process phosphoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, J.A.; Weterings, C.A.

    1983-06-28

    Process for recovering yttrium and lanthanides from wet-process phosphoric acid by adding a flocculant to the phosphoric acid, separating out the resultant precipitate and then recovering yttrium and lanthanides from the precipitate. Uranium is recovered from the remaining phosphoric acid.

  9. Preparation, characterization and thermal behaviour study of double selenates of lanthanides, yttrium and beryllium

    International Nuclear Information System (INIS)

    Ribeiro, C.A.

    1988-01-01

    The lanthanides (III) and yttrium (III) double selenates were studied using common analytical methods, atomic absorption, X-ray diffraction infra-red absorption, thermogravimetry and differential thermal analysis. These compounds were prepared from the mixture of lanthanides (III) and yttrium (III) selenates aqueous solution and basic beryllium selenates aqueous solution, obeying equimolar relation (1:1) to the cation

  10. Adducts compounds of lanthanides (III) trifluoreacetates and yttrium and the N,N - dimenthylformamide

    International Nuclear Information System (INIS)

    Silva, M. das G. da.

    1983-01-01

    Some studies on lanthanides, f transition elements, and yttrium are presented. Adducts of lanthanides trifluoroacetates and N,N -dimethylformamide are described. The characterization of complexes from elementar analysis, conductance measurements, X-ray patterns, vibrational, electronics and fluorescence spectra are analysed. (M.J.C.) [pt

  11. Method of growing yttrium aluminate and/or lanthanide single crystals with perovskite structure

    International Nuclear Information System (INIS)

    Kvapil, Jiri; Perner, B.; Kvapil, Josef; Blazek, K.

    1989-01-01

    Single crystals of yttrium aluminate and/or lanthanide with perovskite structure are grown from melt in a vacuum at a pressure of gas residues of max. 0.01 Pa. The melt contains 1±0.05 gram-ions of aluminium per gram-ion of yttrium and/or lanthanides. The single crystals are then heated in a vacuum (0.01 Pa) at temperatures of 1,450 to 1,800 degC for 2 to 3 hours. (B.S.)

  12. Thermal decomposition of double selenates of lanthanides (III), yttrium (III) and ammonium

    International Nuclear Information System (INIS)

    Crespi, M.S.

    1989-01-01

    Double selenates of lanthanides, yttrium and ammonium were prepared by treating mixtures of simple selenates with equimolar amounts and then dried in a vacuum desiccator containing anhydrous calcium chloride, protected from light. The compounds were studied using the conventional analytical methods such as infrared absorption spectra, X-ray diffraction, differential thermal analysis (DTA), and thermogravimetry (TG). (author)

  13. Yttrium and lanthanides in human lung fluids, probing the exposure to atmospheric fallout

    Energy Technology Data Exchange (ETDEWEB)

    Censi, P., E-mail: censi@unipa.it [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy); I.A.M.C.-CNR - UOS di Capo Granitola, Via faro, 1 - 91026 Torretta Granitola, Campobello di Mazara (TP) (Italy); En.Bio.Tech. - Via Aquileia, 35 90100 Palermo (Italy); Tamburo, E. [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy); Speziale, S. [Deutsches GeoForschungsZentrum, Telegrafenberg, Potsdam, 14473 (Germany); Zuddas, P. [Institut Genie de l' Environnement et Ecodeveloppement and Departement Sciences de la Terre, UMR 5125, Universite Claude Bernard Lyon 1, 2 rue R. Dubois, Bat GEODE 69622 Villeurbanne Cedex (France); Randazzo, L.A. [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy); I.A.M.C.-CNR - UOS di Capo Granitola, Via faro, 1 - 91026 Torretta Granitola, Campobello di Mazara (TP) (Italy); En.Bio.Tech. - Via Aquileia, 35 90100 Palermo (Italy); Institut Genie de l' Environnement et Ecodeveloppement and Departement Sciences de la Terre, UMR 5125, Universite Claude Bernard Lyon 1, 2 rue R. Dubois, Bat GEODE 69622 Villeurbanne Cedex (France); Punturo, R. [Dipartimento di Scienze Geologiche, Universita di Catania, Corso Italia, 55 - 95129 Catania (Italy); Cuttitta, A. [I.A.M.C.-CNR - UOS di Capo Granitola, Via faro, 1 - 91026 Torretta Granitola, Campobello di Mazara (TP) (Italy); Arico, P. [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy)

    2011-02-28

    Inhalation of airborne particles can produce crystallization of phosphatic microcrysts in intraaveolar areas of lungs, sometimes degenerating into pulmonary fibrosis. Results of this study indicate that these pathologies are induced by interactions between lung fluids and inhaled atmospheric dust in people exposed to volcanic dust ejected from Mount Etna in 2001. Here, the lung solid-liquid interaction is evaluated by the distribution of yttrium and lanthanides (YLn) in fluid bronchoalveolar lavages on selected individuals according the classical geochemical approaches. We found that shale-normalised patterns of yttrium and lanthanides have a 'V shaped' feature corresponding to the depletion of elements from Nd to Tb when compared to the variable enrichments of heavy lanthanides, Y, La and Ce. These features and concurrent thermodynamic simulations suggest that phosphate precipitation can occur in lungs due to interactions between volcanic particles and fluids. We propose that patterns of yttrium and lanthanides can represent a viable explanation of some pathology observed in patients after prolonged exposure to atmospheric fallout and are suitable to become a diagnostic parameter of chemical environmental stresses.

  14. Addition compounds of yttrium and lanthanide perrhenates with tetramethylene sulphoxide

    International Nuclear Information System (INIS)

    Umeda, K.

    1977-01-01

    Adducts of lanthanide perrhenates with tetramethylene sulfoxide are prepared and characterized. The compounds having as general formula Ln(Re04) 3 .7.5 TMSO(ln=La-Lu and Y) are characterized by elemental analysis, infrared spectra, molar conductance measurements, x-ray powder patterns, differential scanning calorimetry curves, melting temperature range measurements and thermogravimetric analysis [pt

  15. Method of cerium separation from other lanthanides and yttrium

    International Nuclear Information System (INIS)

    Tran, Duc Hiep; Mostecky, J.

    1988-01-01

    Cerium is separated from a suspension produced during the aerial oxidation process. The suspension is subject to a cyclic process of two-stage fractional dissolution. Following the first dissolution, almost all cerium remains undissolved while 95% of the other lanthanides pass into the solution. The filtrate of the second stage of dissolution containing about 5% of ceriumm is returned for oxidation with the next batch of hydroxide mixed concentrate. Following oxidation, the two-stage fractional dissolution is repeated. This cycling provides quantitative cerium separation from other rare earth elements. (E.S.)

  16. The commercial production of compounds of the lanthanides and yttrium as CRT phosphor precursors

    International Nuclear Information System (INIS)

    Kilbourn, B.T.

    1987-01-01

    The consumer acceptance of color television at the start of the 60's was triggered by the phosphor industry's discovery and production of a satisfactory red phosphor using the element europium. This element, in the middle of the lanthanide series, had until that time been an academic curiosity, prepared only in gram quantities for research. The large-scale production by the lanthanide industry, in order to meet the demand for commercial quantities of high purity europium oxide, required the introduction of new technology. Lanthanide elements other than europium, such as cerium and terbium, are also needed as the active ions for many phosphors. In addition, the inert host lattice for those emitting ions can be provided by compounds of yttrium, the element above the lanthanides in the periodic table, with comparable properties. The lanthanide industry has developed processes to produce compounds of such elements in the required quantities and purities. For commercial separation of these elements a technology known as counter-current liquid-liquid extraction has been developed. This technique, commonly called solvent extraction, is illustrated and described. The initial ore preparation steps, together with the final high purity oxide production is also mentioned

  17. Interaction of phosphorus pentachloride with trichlorides of metals of the second half of lanthanide series and scandium subgroup

    International Nuclear Information System (INIS)

    Salyulev, A.B.; Vovkotrub, Eh.G.; Strekalovskij, V.N.

    1999-01-01

    With the use of Raman laser spectroscopy a study is made into interactions of molten TbCl 3 , ErCl 3 , YbCl 3 , YCl 3 and ScCl 3 with phosphorus pentachloride vapors at elevated pressure (up to 30-35 atm) as well as solid REM trichlorides with molten PCl 5 . It is revealed for first time that the interaction can be accompanied by reactions resulting in formation of complex chloride cations [PCl 4 ] + and anions [MCl 6 ] 3- of trivalent metals. The prediction is made about the possibility of chemical interaction of phosphorus pentachloride with trichlorides of all yttrium subgroup lanthanides under similar conditions

  18. Biamperometric analysis of nonaqueous scandium solutions containing lanthanides, lead and thorium

    International Nuclear Information System (INIS)

    Gevorgyan, A.M.; Talipov, Sh.T.; Kostylev, V.S.; Khadeev, V.A.; Nadol'skij, M.Ya.

    1978-01-01

    Investigated was a possibility of direct scandium titration in the presence of large rare earth quantities, and also a possibility of complexonometric scandium and rare earth sum determination at their joint presence in non-aqueous acetic acid solution. The titration was carried out at electrode voltage of 0.95V, background electrolyte concentration of lithium perchlorate being 0.2M. Non-aqueous magnesium complexonate was used as titrating reagent. Th and Pb complexonates are shown to be less stable as compared to Sc complexonate, and consequently, Th and Pb ions must not interfere with biamperometric titration of Sc ion. A method applied to analysis of binary mixture, containing scandium, and a method for model alloy and thortveitite mineral was developed. Well reproducible and precise enough results are obtained in all the cases. Ions of Bi, Cu, Cd, Zn, In, Ga and Ti interfere with determination

  19. Studies for the yttrium determination by activation analysis, in the presence of lanthanides. Application of the substoichiometric technique

    International Nuclear Information System (INIS)

    Silva, D.I.T. da.

    1978-01-01

    Some methods using extraction chromatography for the separation of yttrium from the lanthanide elements were applied. The separation of yttrium was studied, using di-(2 ethylhexyl) orthophosphoric acid as stationary phase, Kieselguhr as support and HNO 3 of concentration between 4,5 and 5,0 N as the mobile phase. In these conditions, about 50% of pure yttrium was obtained. The substoichiometric technique was applied to the determination of yttrium. The elements was partially complexed and the Y 3 + ions were separated from the complex (EDTA-Y) - by means of a cationic resin. The sensitivity, precision and accuracy which can be expected in the analytical results were studied. The possibility of the analysis of a sample containing 1 part per million of yttrium with an error just above 8% was demonstrated. It was also shown that, admitting an error of 10%, it is possible to determine 60 parts per billion of yttrium [pt

  20. Determination of rare-earth elements, yttrium and scandium in manganese nodules by inductively-coupled argon-plastma emission spectrometry

    Science.gov (United States)

    Fries, T.; Lamothe, P.J.; Pesek, J.J.

    1984-01-01

    A sequential-scanning, inductively-coupled argon plasma emission spectrometer is used for the determination of the rare-earth elements, plus yttrium and scandium, in manganese nodules. Wavelength selection is optimized to minimize spectral interferences from manganese nodule components. Samples are decomposed with mixed acids in a sealed polycarbonate vessel, and elements are quantified without further treatment. Results for U.S. Geological Survey manganese nodule standards A-1 and P-1 had average relative standard deviations of 6.8% and 8.1%, respectively, and results were in good agreement with those obtained by other methods. ?? 1984.

  1. Thermal decomposition of lanthanides (III) and yttrium (III) solid complexes from ethyl ene diamine tetraacetic acid

    International Nuclear Information System (INIS)

    Mercadante, A.

    1991-01-01

    Solid state compounds of lanthanides (III) and yttrium derived from ethyl ene diamine tetraacetic acid were prepared from respective basic carbonates, that were neutralized with EDTA stoichiometry quantities. Complexometry with EDTA, thermogravimetry (TG), differential thermal analysis (DTA) and X-ray diffraction have been used in the study of these compounds. The results of complexometry with EDTA as well as TG and DTA curves bed to the stoichiometry of these compounds the following general formula is obeyed: H[Ln(EDTA]. n H 2 O. X-ray powder patterns of these compounds permitted to establish two isomorphous series. The DTA ant TG curves allowed us to study the dehydration process, the thermal stability and thermal decomposition of these compounds. (C.G.C.)

  2. Yttrium and lanthanide nitrate complexes of N,N1-bis(4-antipyryl methylidene) ethylenediamine

    International Nuclear Information System (INIS)

    Joseph, Siby; Radhakrishnan, P.K.

    1998-01-01

    Complexes of yttrium and lanthanide nitrates with a Schiff base, N, N 1 -bis(4-antipyrylmethylidene)ethylenediamine (BAME) having the general formula [Ln(BAME) 2 (NO 3 )](NO 3 ) 2 , where Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho and Er have been synthesised and characterised by elemental analyses, molar conductance in non-aqueous solvents, electronic, infrared and proton NMR spectra. BAME acts as a neutral bidentate ligand coordinating through both azomethine nitrogen atoms. One of the nitrate groups is coordinated in a bidentate manner. A coordination number of six may be assigned to the metal ion in these complexes. The covalency parameters evaluated from the solid state electronic spectra suggest weak covalent character of the metal-ligand bond. (author)

  3. Complexes between lanthanide (III) and yttrium (III) picrates and tetra methylene sulfoxide as ligand

    International Nuclear Information System (INIS)

    Silva, M.A.A. da.

    1991-01-01

    The preparation and characterization of addition compounds between lanthanide (III) and yttrium (III) picrates and tetra methylene sulfoxide as ligand were described. The adducts were prepared in the molar relation 1 (salt): 3(ligand) in ethanol. They are microcrystalline with more intense color than those of their respective hydrated salts. At room temperature conditions they are non hygroscopic and do not present perceptible alterations. They became slightly opalescent, when heated between 363 and 423 K. At higher temperatures under several heating ratios, the behavior shown is the same: melting between 439 and 472 K. The characterization of the compounds was made by elemental analysis, electrolytic conductance measurements, X-ray powder patterns, infrared spectroscopy, visible electronic absorption and emission spectra of the neodymium (III) and europium (III), respectively. (author). 116 refs., 17 tabs., 11 figs

  4. Stability constants of mixed ligand complexes of lanthanide(III) and yttrium(III) with complexone and substituted salicylic acids

    International Nuclear Information System (INIS)

    Kolhe, Vishnu; Dwivedi, K.

    1996-01-01

    Salicylic acid and substituted salicylic acids are potential antimicrobial agents. Binary complexes of salicylic acid and its substituted derivatives with lanthanide(III) and yttrium(III) metal ions have been reported. There are reports on the ternary metal complexing equilibria with some lanthanide(III) and yttrium(III) metal ions involving aminopolycarboxylic acid as one ligand and salicylic acid (SA) and other related compounds as the second ligands. Ethylene glycol bis(2-aminoethylether)- N, N, N', N'-tetraacetic acid (EGTA) is an important member of aminopolycarboxylic acid and finds many applications in medicine and biology. Recently, few ternary complexes have been reported using EGTA as ligand. In view of biological importance of simple and mixed ligand complexes EGTA, SA and DNSA (3,5-dinitrosalicylic acid), a systematic study has been undertaken for the determination of stability constant and the results are reported. (author). 6 refs., 1 fig., 2 tabs

  5. Accurate determination of trace amounts of lanthanum, yttrium and all stable lanthanides in biological materials by Ion Chromatography

    International Nuclear Information System (INIS)

    Dybczynski, R.S.; Kulisa, K.; Danko, B.; Samczynski, Z.

    2007-01-01

    The analytical procedure for the isolation and preconcentration of La, Y and the lanthanides from biological materials and their determination by ion chromatography (IC) with the use of Dionex Ion Pac CS3 + CG3 column (sulfonic acid type), α-hydroxyisobutyric acid (α-HIBA) as an eluent, and PAR or Arsenazo III as color forming reagents, was elaborated. The scheme originally devised for NAA, involving microwave assisted digestion and multi step separation employing ion exchange and extraction chromatography columns was used to selectively recover REE fraction (without scandium) with 100% yield. The REE fraction was analyzed by IC at 25 and 70 o C. The run at 70 o C enabled resolution of Y and Dy peaks and as a result made possible quantitative determination of La, Y, and all lanthanides. Investigation on the mechanism of band spreading revealed that longitudinal diffusion in the stationary phase considerably contributed to the total plate height. Surprisingly, the plate height (H) calculated from Y peak was distinctly lower than H values of the adjacent lanthanides. The method was validated by analyzing several certified reference materials (CRMs). (authors)

  6. Complexes of (III) lanthanides isothiocyanate and (III) yttrium with 2,6-lutidine-n-oxide (2,6-LNO)

    International Nuclear Information System (INIS)

    Arico, E.M.

    1990-01-01

    The preparation and characterization of the complexes of yttrium and some lanthanides isothiocyanate with 2,6-lutidine-N-oxide (2,6-LNO) are described. The ligand employed in the synthesis of the compounds were prepared by the reaction of 2,6-lutidine with hydrogen peroxide in glacial acetic acid. The complexes were prepared using the relation 1:3 salt-ligand. Their characterization was made by elemental analysis, electrolytic conductance measurements, X-ray powder patterns, infrared spectra, electronic absorption spectra of the neodymium and fluorescence spectra of the europium compounds. (author)

  7. Thermal effects from modified endodontic laser tips used in the apical third of root canals with erbium-doped yttrium aluminium garnet and erbium, chromium-doped yttrium scandium gallium garnet lasers.

    Science.gov (United States)

    George, Roy; Walsh, Laurence J

    2010-04-01

    To evaluate the temperature changes occurring on the apical third of root surfaces when erbium-doped yttrium aluminium garnet (Er:YAG) and erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser energy was delivered with a tube etched, laterally emitting conical tip and a conventional bare design optical fiber tip. Thermal effects of root canal laser treatments on periodontal ligament cells and alveolar bone are of concern in terms of safety. A total of 64 single-rooted extracted teeth were prepared 1 mm short of the working length using rotary nickel-titanium Pro-Taper files to an apical size corresponding to a F5 Pro-Taper instrument. A thermocouple located 2 mm from the apex was used to record temperature changes arising from delivery of laser energy through laterally emitting conical tips or plain tips, using an Er:YAG or Er,Cr:YSGG laser. For the Er:YAG and Er,Cr:YSGG systems, conical fibers showed greater lateral emissions (452 + 69% and 443 + 64%) and corresponding lower forward emissions (48 + 5% and 49 + 5%) than conventional plain-fiber tips. All four combinations of laser system and fiber design elicited temperature increases less than 2.5 degrees C during lasing. The use of water irrigation attenuated completely the thermal effects of individual lasing cycles. Laterally emitting conical fiber tips can be used safely under defined conditions for intracanal irradiation without harmful thermal effects on the periodontal apparatus.

  8. Addition compounds of perchlorates from yttrium and lanthanides elements with the N,N,N',N'tetramethyl amide of phthalic acid

    International Nuclear Information System (INIS)

    Silva, C.P.G. da.

    1974-01-01

    The reaction between lanthanide perchlorates and yttrium with tetra methyl phthalamide (TMPA) was studied, and compounds of the general formula Ln (C 10 4 ) 3 . TMPA have been isolated. The compounds were characterized by analysis of their components, infra-red spectra, molar conductances in nitromethane and nitrobenzene, X ray powder patterns and thermal analysis. (author)

  9. Comparative evaluation of surface topography of tooth prepared using erbium, chromium: Yttrium, scandium, gallium, garnet laser and bur and its clinical implications.

    Science.gov (United States)

    Verma, Mahesh; Kumari, Pooja; Gupta, Rekha; Gill, Shubhra; Gupta, Ankur

    2015-01-01

    Erbium, chromium: Yttrium, scandium, gallium, garnet (Er, Cr: YSGG) laser has been successfully used in the ablation of dental hard and soft tissues. It has been reported that this system is also useful for preparing tooth surfaces and etching, but no consensus exist in the literature regarding the advantage of lasers over conventional tooth preparation technique. Labial surfaces of 25 extracted human maxillary central incisors were divided into two halves. Right half was prepared with diamond bur and left half with Er, Cr; YSGG laser and a reduction of 0.3-0.5 mm was carried out. Topography of prepared surfaces of five teeth were examined under scanning electron microscope (SEM). The remaining samples were divided into 4 groups of 10 specimens each based on the surface treatment received: One group was acid etched and other was nonetched. Composite resin cylinders were bonded on prepared surfaces and shear bond strength was assessed using a universal testing machine. The SEM observation revealed that the laser prepared surfaces were clean, highly irregular and devoid of a smear layer. Bur prepared surfaces were relatively smooth but covered with smear layer. Highest bond strength was shown by laser prepared acid etched group, followed by bur prepared the acid etched group. The bur prepared nonacid etched group showed least bond strength. Er, Cr: YSGG laser can be used for preparing tooth and bond strength value achieved by laser preparation alone without surface treatment procedure lies in the range of clinical acceptability.

  10. Investigation of concentration-dependence of thermodynamic properties of lanthanum, yttrium, scandium and terbium in eutectic LiCl-KCl molten salt

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yafei; Zhou, Wentao; Zhang, Jinsuo, E-mail: zhang.3558@osu.edu

    2016-09-15

    Thermodynamic properties of rare earth metals in LiCl-KCl molten salt electrolyte are crucial to the development of electrochemical separation for the treatment of used nuclear fuels. In the present study, activity coefficient, apparent potential, and diffusion coefficient of lanthanum, yttrium, scandium, and terbium in the molten salt (58 at% LiCl and 42 at% KCl) were calculated by the method of molecular dynamics simulation up to a concentration around 3 at% at temperatures of 723 K and 773 K. It was found that the activity coefficient and the apparent potential increase with the species concentration while diffusion coefficient shows a trend of increase followed by decrease. The calculated results were validated by available measurement data of dilution cases. This research extends the range of data to a wide component and would provide further insight to the pyroprocessing design and safeguards. - Highlights: • Investigation of activity coefficient, apparent potential and diffusion coefficient at different concentrations. • MD simulation was studied for the calculation of thermodynamic properties of rare earth elements in molten salt. • The present study is a pioneering work focusing on the concentration dependence of thermodynamic properties.

  11. Adducts of between lanthanide (III) trifluoromethanesulfonate and yttrium (III) and tetramethylene sulphoxide ligand

    International Nuclear Information System (INIS)

    Assis Araujo, F. de.

    1983-01-01

    The synthesis, characterization and spectroscopic properties of lanthanides trifluoromethanesulfonate complexes with tetramethylenesulfoxide (TMSO), are described. The interpretation of X-ray powder patterns show one isomorphous series. (M.J.C.) [pt

  12. Thermoanalytical, spectroscopic and DFT studies of heavy trivalent lanthanides and yttrium(III) with oxamate as ligand

    Energy Technology Data Exchange (ETDEWEB)

    Caires, Flavio Junior; Gaglieri, Caroline, E-mail: caires.flavio@fc.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Bauru, SP (Brazil). Faculdade de Ciencias; Nunes, Wilhan Donizete Goncalves; Nascimento, Andre Luiz Carneiro Soares do; Teixeira, Jose Augusto; Zangaro, Georgia Alvim Coelho; Treu-Filho, Oswaldo; Ionashiro, Massao [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil)

    2017-07-15

    Solid-state LnL{sub 3}∙nH{sub 2}O complexes, where Ln stands for trivalent lanthanides (Tb to Lu) or yttrium(III) and L is oxamate (NH{sub 2}COCO{sub 2}{sup -}), have been synthesized. The characterization of the complexes was performed by using elemental analysis (EA), complexometric titration with EDTA, thermoanalytical techniques such as simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC), evolved gas analysis (TG-FTIR), infrared spectroscopy (IR) and powder X-ray diffraction (XRPD). The results provided information about thermal behavior, crystallinity, stoichiometry, coordination sites, as well as the products released during thermal degradation of the complexes studied. Theoretical calculation of yttrium oxamate, as representative of all complexes was performed using density functional theory (DFT) for studying the molecular structure and vibrational spectrum of the investigated molecule in the ground state. The optimized geometrical parameters and theoretical vibrational spectrum obtained by DFT calculations are in good agreement with the experimental results. (author)

  13. Comparative study of the shear bond strength of composite resin bonded to enamel treated with acid etchant and erbium, chromium: Yttrium, scandium, gallium, garnet laser

    Directory of Open Access Journals (Sweden)

    Adel Sulaiman Alagl

    2016-01-01

    Full Text Available Aim: The purpose of this investigation is in vitro comparison of the shear bond strength (SBS of composite resin bonded to enamel pretreated with an acid etchant against enamel etched with erbium, chromium: yttrium, scandium, gallium, garnet (Er, Cr:YSGG laser. Materials and Methods: Sixty premolars were sectioned mesiodistally and these 120 specimens were separated into two groups of 60 each (Groups A and B. In Group A (buccal surfaces, enamel surface was etched using 37% phosphoric acid for 15 s. In Group B (lingual surfaces, enamel was laser-etched at 2W for 10 s by Er, Cr:YSGG laser operational at 2780 nm with pulse duration of 140 μs and a frequency of 20 Hz. After application of bonding agent on all test samples, a transparent plastic cylinder of 1.5 mm × 3 mm was loaded with composite and bonded by light curing for 20 s. All the samples were subjected to SBS analysis using Instron Universal testing machine. Failure modes were observed under light microscope and grouped as adhesive, cohesive, and mixed. Failure mode distributions were compared using the Chi-square test. Results: SBS values obtained for acid-etched enamel were in the range of 7.12–28.36 megapascals (MPa and for laser-etched enamel were in the range of 6.23–23.35 MPa. Mean SBS for acid-etched enamel was 15.77 ± 4.38 MPa, which was considerably greater (P < 0.01 than laser-etched enamel 11.24 ± 3.76 MPa. The Chi-square test revealed that the groups showed no statistically significant differences in bond failure modes. Conclusions: We concluded that the mean SBS of composite with acid etching is significantly higher as compared to Er, Cr: YSGG (operated at 2W for 10 s laser-etched enamel.

  14. Preparation, characterization and thermal behaviour study of 4-dimethyl amino benzal pyruvate of lanthanides (III) and yttrium (III) in solid state

    International Nuclear Information System (INIS)

    Miyano, M.H.

    1990-01-01

    Solid state compounds involving Ln and DMBP, where Ln trivalent lanthanides (except promethium) and yttrium; DMBP 4-dimethyl amino benzylidene pyruvate, were prepared by addition of ligand to the corresponding metal ions chlorides, both in aqueous solution. The precipitates were washed with distilled water and dried at 40 0 C in a forced circulation oven. Complexometry with EDTA, thermogravimetry (TG), differential thermal analysis (DTA), infra-red absorption and X-ray diffraction have been used in the study of these compounds. (author)

  15. On the elimination of cerium in lanthanides such as lanthanum, yttrium and europium

    International Nuclear Information System (INIS)

    Ishii, Eiichi; Miyake, Yoshizo

    1974-01-01

    The following two methods have been investigated for the separation of Ce, containing 0.002-1.0% in lanthanides such as La, Y and Eu. (1) Treatment of lanthanide oxides containing Ce by dilute acids. (2) Elimination of Ce by the conversion of its valency state and by the additional effect using scavenger. The concentration of Ce was determined using radiotracer techniques. The first method was unsuitable because Ce was highly soluble even in dilute acetic acid. In the case of the second method, the percentage of separaton of Ce in La or Y were 97-99% by the use of the scavenger, regardless of Ce contents. When 0.002-0.5% of Ce was contained in Y or Eu, high elimination percentage (98-99%) of Ce was obtained by the conversion of the valency state of Ce because of the formation of colloidal solutions

  16. Addition compounds of lanthanide-and yttrium trifluoromethanesulfonates and N,N-dimethylacetamide (DMA)

    International Nuclear Information System (INIS)

    Vicentini, G.; Tamura, T.

    1982-01-01

    Preparation of addition compounds of hydrated lanthanide trifluoromethanesulfonates and DMA, with general formula Ln (CF 3 SO 3 ) 3 .6H 2 O.x DMA is described. The compounds obtained are characterized by elemental analysis, X-ray diagrams, infrared absorption spectra, electrolytical conductance in nitromethane and acetonitrile, absorption spectra of the neodymium compound and emission spectra of the europium compound. (A.R.H.) [pt

  17. Polymerization of lanthanide acrylonitrile complexes.

    Science.gov (United States)

    el-Mossalamy, El-Sayed H; Khalil, Ahmed A

    2002-01-01

    The molecular complexes of some lanthanides scandium (Sc3+), yttrium (Y3+), lanthanum (La3+), gadolinium (Gd3+), cerium (Ce3+) and ytterbium (Yb3) have been studies in dimethyl formamide (DMF) spectrophtometrically equilibrium constants (K), molar extintion coefficient (epsilon), energy of transition (E) and free energy (delta G*) were calculated. The polymerization of acrylonitrile has been studied and investigated in the presence of Sc3+, Y3+, La3+, Gd3+, Ce3+, and Yb3+ ions. The IR spectra of the formed AN-M (III) Br3 polymer complexes show the absence of the C identical to N band and the presence of two new bands corresponding to NH2 and OH groups. Magnetic moment values and the thermal stabilities of homopolymer and the polymer complexes were studied by means of thermogravimetric analysis and the activation energies for degradation were calculated.

  18. Electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of trace amount of lanthanides and yttrium in soil with polytetrafluroethylene emulsion as a chemical modifier

    International Nuclear Information System (INIS)

    He Man; Hu, Bin; Jiang Zucheng

    2005-01-01

    A method of electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the determination of trace lanthanides and yttrium in soil samples with a polytetrafluorethylene (PTFE) emulsion as chemical modifier to promote the vaporization of the analytes from the graphite furnace was developed in this paper. The analytical characteristics, spectral interference and matrix effect of the analytical method were evaluated and critically compared with those of pneumatic nebulization inductively coupled plasma mass spectrometry (PN-ICP-MS). Under the optimized operation conditions, the relative detection limits of lanthanides (La-Lu) and yttrium for ETV-ICP-MS and PN-ICP-MS were 0.4-20 ng l -1 and 1.0-21 ng l -1 , respectively, the absolute detection limits for ETV-ICP-MS were 4-200 fg, which were improved by 1-2 orders of magnitude compared with PN-ICP-MS. While the analytical precision of ETV-ICP-MS is worse than that of PN-ICP-MS, with the R.S.D.s (%) of 4.1-10% for the former and 2.9-7.8% for the latter. Regarding to the matrix effect, both conventional method and stepwise dilution method were employed to observe the effect of matrix and the very similar results were obtained. It was found that the highest tolerance concentration of the matrix is 1000 mg l -1 and 800 mg l -1 for ETV-ICP-MS and PN-ICP-MS, respectively. To assess the accuracy, the proposed method was applied to the determination of trace lanthanides and yttrium in three different soil standard reference materials and one soil sample, and the determined values are in good agreement with the certified values or reference values

  19. Binary and ternary chelates of scandium (III), Yttrium (III) and lanthanum (III) with ethyleneglycol-bis(. beta. -aminoethylether)-tetraacetic acid as primary and substituted salicylic acids as secondary ligands

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, A K; Chandra, M; Agarwala, B V; Dey, A K [Allahabad Univ. (India). Chemical Labs.

    1980-01-01

    Formation constants of binary and ternary complexes of the systems of the type: M-L and M-egta-L (M = scandium(III), yttrium(III) and lanthanum(III), egta = ethylene glycol-bis(..beta..-aminoethylether)-tetra acetic acid, L = o-cresotic acid (o-ca), m-cresotic acid (m-ca), 5-chlorosalicyclic acid(csa), and 3,5-dibromosalicylic acid (dbsa)) have been determined pH-metrically at 25deg and ..mu.. = 0.1M (KNO/sub 3/) in 50% (v/v) aqueous-ethanol medium. The order of stabilities of ternary complexes has been compared with those of corresponding binary complexes, and results discussed on the basis of coulombic interactions.

  20. Interaction of phosphorus pentachloride with trichlorides of metals of the second half of lanthanide series and scandium subgroup; Vzaimodejstvie pentakhlorida fosfora s trikhloridami metallov vtoroj poloviny semejstva lantanidov i podgruppy skandiya

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, A B; Vovkotrub, Eh G; Strekalovskij, V N [Inst. Vysokotemperaturnoj Ehlektrokhimii UrO RAN, Ekaterinburg (Russian Federation)

    1999-02-01

    With the use of Raman laser spectroscopy a study is made into interactions of molten TbCl{sub 3}, ErCl{sub 3}, YbCl{sub 3}, YCl{sub 3} and ScCl{sub 3} with phosphorus pentachloride vapors at elevated pressure (up to 30-35 atm) as well as solid REM trichlorides with molten PCl{sub 5}. It is revealed for first time that the interaction can be accompanied by reactions resulting in formation of complex chloride cations [PCl{sub 4}]{sup +} and anions [MCl{sub 6}]{sup 3-} of trivalent metals. The prediction is made about the possibility of chemical interaction of phosphorus pentachloride with trichlorides of all yttrium subgroup lanthanides under similar conditions.

  1. Addition compounds between lanthanide (III) and yttrium (III) and methanesulfonates (MS) and 3-picoline-N-oxide (3-pic NO)

    International Nuclear Information System (INIS)

    Zinner, L.B.

    1984-01-01

    The preparation and characterization of addition compounds between lanthanide methanesulfonates and 3-picoline-N-oxide of general formula Ln (MS) 3 .2(3-pic No), Ln being La, Yb and Y, were carried out. The techniques employed for characterization were: elemental analysis, X-ray diffraction, infrared absorption spectroscopy, electrolytic conductance in methanol, melting ranges and emission spectrum of the Eu (III) compound. (Author) [pt

  2. Scandium fluorides

    International Nuclear Information System (INIS)

    Melnikov, P.; Nalin, M.; Messaddeq, Y.

    1997-01-01

    A new modification of scandium fluoride has been synthesised. The compound is deficient in fluorine, with the composition ScF 2.76 . It belongs to the tetragonal system, lattice parameters being a=3.792 and c=6.740 A and may be obtained at low temperatures by the decomposition of the precursor NH 4 ScF 4 . The reaction is topotactic, tetragonal parameters of the precursor are a=4.021 and c=6.744 A. Structural relationships with various fluorides and ammonium aminofluorides are discussed. This synthesis route with IR-assisted decomposition should be considered as a soft-chemistry approach. (orig.)

  3. Determination of the fission products yields, lanthanide and yttrium, in the fission of 238U with neutrons of fission spectra

    International Nuclear Information System (INIS)

    Nicoli, I.G.

    1981-06-01

    A radiochemical investigation is performed to measure the cumulative fission product yields of several lantanides and yttrium nuclides in the 238 U by fission neutron spectra. Natural and depleted uranium are irradiated under the same experimental conditions in order to find a way to subtract the contribution of the 235 U fission. 235 U percentage in the natural uranium was 3.5 times higher than in the depleted uranium. Uranium oxides samples are irradiated inside the core of the Argonaut Reactor, at the Instituto de Engenharia Nuclear, and the lantanides and yttrium are chemically separated. The fission products gamma activities were detected, counted and analysed in a system constituted by a high resolution Ge(Li) detector, 4096 multichannel analyser and a PDP-11 computer. Cumulative yields for fission products with half-lives between 1 to 33 hours are measured: 93 Y, 141 La, 142 La, 143 Ce and 149 Nd. The chain total yields are calculated. The cumulative fission yields measured for 93 Y, 141 La, 142 La, 143 Ce and 149 Nd are 4,49%, 4,54%, 4,95%, 4,16% and 1,37% respectively and they are in good agreement with the values found in the literature. (Author) [pt

  4. Scandium Terminal Imido Chemistry.

    Science.gov (United States)

    Lu, Erli; Chu, Jiaxiang; Chen, Yaofeng

    2018-02-20

    Research into transition metal complexes bearing multiply bonded main-group ligands has developed into a thriving and fruitful field over the past half century. These complexes, featuring terminal M═E/M≡E (M = transition metal; E = main-group element) multiple bonds, exhibit unique structural properties as well as rich reactivity, which render them attractive targets for inorganic/organometallic chemists as well as indispensable tools for organic/catalytic chemists. This fact has been highlighted by their widespread applications in organic synthesis, for example, as olefin metathesis catalysts. In the ongoing renaissance of transition metal-ligand multiple-bonding chemistry, there have been reports of M═E/M≡E interactions for the majority of the metallic elements of the periodic table, even some actinide metals. In stark contrast, the largest subgroup of the periodic table, rare-earth metals (Ln = Sc, Y, and lanthanides), have been excluded from this upsurge. Indeed, the synthesis of terminal Ln═E/Ln≡E multiple-bonding species lagged behind that of the transition metal and actinide congeners for decades. Although these species had been pursued since the discovery of a rare-earth metal bridging imide in 1991, such a terminal (nonpincer/bridging hapticities) Ln═E/Ln≡E bond species was not obtained until 2010. The scarcity is mainly attributed to the energy mismatch between the frontier orbitals of the metal and the ligand atoms. This renders the putative terminal Ln═E/Ln≡E bonds extremely reactive, thus resulting in the formation of aggregates and/or reaction with the ligand/environment, quenching the multiple-bond character. In 2010, the stalemate was broken by the isolation and structural characterization of the first rare-earth metal terminal imide-a scandium terminal imide-by our group. The double-bond character of the Sc═N bond was unequivocally confirmed by single-crystal X-ray diffraction. Theoretical investigations revealed the presence

  5. Ion exchange purification of scandium

    Science.gov (United States)

    Herchenroeder, Laurie A.; Burkholder, Harvey R.

    1990-10-23

    An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity.

  6. Secret lanthanides.

    Science.gov (United States)

    Sturza, C M

    2014-09-15

    Lanthanides are a group of 15 chemical elements which, together with their salts, have come to be used in the last decade as homoeopathic remedies. The effective introduction of lanthanides and their salts into the clinical use, as homoeopathic remedies was based on the idea of Jan Scholten, MD to relate their physicochemical properties shown in the periodic table of elements to their homoeopathic potential. The lanthanides and their salts were prepared as homoeopathic remedies by Pharmacist Robert Münz.

  7. Specification and comparative calculation of enthalpies and Gibbs formation energies of anhydrous lanthanide nitrates

    International Nuclear Information System (INIS)

    Del' Pino, Kh.; Chukurov, P.M.; Drakin, S.I.

    1980-01-01

    Analyzed are the results of experimental depermination of formation enthalpies of waterless nitrates of lanthane cerium, praseodymium, neodymium and samarium. Using method of comparative calculation computed are enthalpies of formation of waterless lanthanide and yttrium nitrates. Calculated values of enthalpies and Gibbs energies of waterless lanthanide nitrate formation are tabulated

  8. Stability constants of scandium complexes, 1

    International Nuclear Information System (INIS)

    Itoh, Hisako; Itoh, Naomi; Suzuki, Yasuo

    1984-01-01

    The stability constants of scandium complexes with some carboxylate ligands were determined potentiometrically at 25.0 and 40.0 0 C and at an ionic strength of 0.10 with potassium nitrate as supporting electrolyte. The constants of the scandium complexes were appreciably greater than those of the corresponding lanthanoid complexes, as expected. The changes in free energy, enthalpy, and entropy for the formation of the scandium complexes were calculated from the stability constants at two temperatures. (author)

  9. Low temperature heat capacity of scandium and alloys of scandium

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, T. W.E.

    1977-12-01

    The heat capacity of three electrotransport purified scandium samples has been measured from 1 to 20/sup 0/K. The resultant electronic specific heat constant and Debye temperature are 10.337 +- 0.015 mJ/gm-atom K/sup 2/ and 346.7 +- 0.8/sup 0/K respectively, and these values are believed to be truly representative of intrinsic scandium. Alloying studies have also been carried out to investigate the band structure of scandium based on the rigid band model, with zirconium to raise the electron concentration and magnesium to lower it. The results are then compared to the theoretical band structure calculations. Low temperature heat capacity measurements have also been made on some dilute Sc-Fe alloys. An anomaly is observed in the C/T vs. T/sup 2/ plot, but the C vs. T curve shows no evidence of magnetic ordering down to 1/sup 0/K, and electrical resistance measurement from 4 to 0.3/sup 0/K also indicates that no magnetic ordering took place.

  10. Yttrium-90

    International Nuclear Information System (INIS)

    Ammerich, Marc; Frot, Patricia; Gambini, Denis-Jean; Gauron, Christine; Moureaux, Patrick; Herbelet, Gilbert; Lahaye, Thierry; Pihet, Pascal; Rannou, Alain; Vial, Eric

    2013-03-01

    This sheet belongs to a collection which relates to the use of radionuclides essentially in unsealed sources. Its goal is to gather on a single document the most relevant information as well as the best prevention practices to be implemented. These sheets are made for the persons in charge of radiation protection: users, radioprotection-skill persons, labor physicians. Each sheet treats of: 1 - the radio-physical and biological properties; 2 - the main uses; 3 - the dosimetric parameters; 4 - the measurement; 5 - the protection means; 6 - the areas delimitation and monitoring; 7 - the personnel classification, training and monitoring; 8 - the effluents and wastes; 9 - the authorization and declaration administrative procedures; 10 - the transport; and 11 - the right conduct to adopt in case of incident or accident. This sheet deals specifically with Yttrium-90

  11. Photocytotoxic lanthanide complexes

    Indian Academy of Sciences (India)

    Among many applications of lanthanides, gadolinium complexes are used as magnetic resonance imaging (MRI) contrast agents in clinical radiology and luminescent lanthanides for bioanalysis, imaging and sensing. The chemistry of photoactive lanthanide complexes showing biological applications is of recent origin.

  12. Thermodynamic characteristics of systems with solid solutions composed of crystal hydrates of lanthanide and yttrium chlorides, at 250C. III. Systems of Roozeboom's type IV, with restricted solid solutions

    International Nuclear Information System (INIS)

    Sokolova, N.P.

    1983-01-01

    The values of the activity, the activity coefficients, the free energy of mixing and the excess free energy of mixing have been calculated for CeCl 3 -LnCl 3 -H 2 O systems (where Ln identical with Sm, Gd, Dy, Ho, Er, Y) containing solid solutions of types IV and IVa. It is shown that the stability of the solid solutions decreases with increasing difference between the radii of the cations of cerium and the second lanthanide, which enter into the composition of the components of the solid solutions. The factors determining the composition of a liquid solution corresponding to the eutonic point are specified

  13. 2. Intermetallic compounds with lanthanides

    International Nuclear Information System (INIS)

    Elemans, J.B.A.A.

    1975-01-01

    Theoretical considerations are given concerning the structures of intermetallic compounds of the lanthanides and thorium (R) on the one hand, and with Fe, Co or Ni (M) on the other. They all derive from the parent composition RM 5 with the CaCu 5 hexagonal structure. This consists of alternate layers in which the M atoms are distinguished as M 1 and M 2 . The other compounds whose structures are studied are obtained by systematic replacement of R by M, or vice versa. In the first type, every third R is replaced by two M's yielding R 2 M 17 compounds. The substitution may be truly random or structured in two ways: so that either the hexagonal structure is maintained or that it is converted into a rhombihedral one. In the second type, one M (in a M 1 position) out of every five is replaced by one R, giving rise to RM 2 compounds which form Laves phases. In the third type, the M 1 's are replaced by R's, resulting in compounds RM 3 . In the fourth type, every third M is replaced by R, yielding R 2 M 7 compounds. With M = Co and R a light lanthanide, the compounds are ferromagnets; with R yttrium, thorium, or a heavy lanthanide, they are ferrimagnets. The preparation of the compounds in an arc-melting apparatus under an Ar-atmosphere followed by annealing is described

  14. Solvent extraction studies on separation of yttrium from xenotime

    International Nuclear Information System (INIS)

    Singh, D.K.; Anitha, M.; Kain, V.

    2017-01-01

    Rare earths consists a group of 15 element from La to Lu in the periodic table and it also includes Sc and Y since they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties. The unique physical-chemical properties of the REEs render them important in applications as varies as high strength magnets, lighting phosphors, policing compounds and ceramics. In particular, yttrium finds numerous applications in many areas including superconductors, lasers, phosphors, nuclear reactors, astronavigation, ceramics etc. Yttrium is chemically similar to heavy rare earths (HRE: terbium, dysprosium, erbium, holmium, ytterbium, thulium and lutecium). Yttrium behaves like HRE due to similarity in ionic radius and finds place between Ho and Er. The cross current profile in terms of the plot of concentration of yttrium in raffinate as a function of contact number indicated the complete recovery of rare earths from nitrate solution of xenotime wet cake

  15. Production of yttrium

    International Nuclear Information System (INIS)

    Day, J.G.

    1980-01-01

    A process is described for the production of yttrium metal, or of an alloy comprising a major proportion of yttrium, in which calcium (metal) and yttrium fluoride are reacted together by use of a submerged electric arc in a molten slag. (author)

  16. Extraction of scandium by organic substance melts

    International Nuclear Information System (INIS)

    Gladyshev, V.P.; Lobanov, F.I.; Zebreva, A.I.; Andreeva, N.N.; Manuilova, O.A.; Il'yukevich, Yu.A.

    1984-01-01

    Regularities of scandium extraction by the melts of octadecanicoic acid, n-carbonic acids of C 17 -C 20 commerical fraction and mixtures of tributylphosphate (TBP) with paraffin at (70+-1) deg C have been studied. The optimum conditions for scandium extraction in the melt of organic substances are determined. A scheme of the extraction by the melts of higher carbonic acids at ninitial metal concentrations of 10 -5 to 10 -3 mol/l has been suggested. The scandium compound has been isolated in solid form, its composition having been determined. The main advantages of extraction by melts are as follows: a possibility to attain high distribution coefficients, distinct separation of phases after extraction, the absence of emulsions, elimination of employing inflammable and toxic solvents, a possibility of rapid X-ray fluorescence determinatinon of scandium directly in solid extract

  17. Extraction of scandium by aromatic carboxylic acids

    International Nuclear Information System (INIS)

    Kamenev, V.F.; Fadeeva, V.I.

    1977-01-01

    Extraction of complex compounds af scandium with salicylic, phenyl- and diphenylacetic acids with chloroform solutions of tetraethyldiamideheptylphosphate as a donor-active additive in relation to the pH and reagent concentration has been studied. Extraction of salicylates of some elements (Ta, Nb, Zr, Hf, Mo) by solutions of tetraethyldiamideheptylphosphate in chloroform has been investigated, and the possibility of their extraction separation from scandium is shown

  18. Extraction of scandium by aromatic carboxylic acids

    Energy Technology Data Exchange (ETDEWEB)

    Kamenev, V F; Fadeeva, V I [Moskovskij Gosudarstvennyj Univ. (USSR)

    1977-04-01

    Extraction of complex compounds af scandium with salicylic, phenyl- and diphenylacetic acids with chloroform solutions of tetraethyldiamideheptylphosphate as a donor-active additive in relation to the pH and reagent concentration has been studied. Extraction of salicylates of some elements (Ta, Nb, Zr, Hf, Mo) by solutions of tetraethyldiamideheptylphosphate in chloroform has been investigated, and the possibility of their extraction separation from scandium is shown.

  19. A basic evaluated neutronic data file for elemental scandium

    International Nuclear Information System (INIS)

    Smith, A.B.; Meadows, J.W.; Howerton, R.J.

    1992-01-01

    This report documents an evaluated neutronic data file for elemental scandium, presented in the ENDF/B-VI format. This file should provide basic nuclear data essential for neutronic calculations involving elemental scandium. No equivalent file was previously available

  20. Double tungstates of metals of scandium and ammonium subgroups

    Energy Technology Data Exchange (ETDEWEB)

    Maksin, V I [AN Ukrainskoj SSR, Kiev. Inst. Kolloidnoj Khimii i Khimii Vody

    1980-06-01

    The methods of pH-potentiometry, conductometry, determination of residual concentrations of liquid phases and precipitations, selected by chemical analysis have been used for investigation R(NO/sub 3/)/sub 3/-(NH/sub 4/)/sub 2/WO/sub 2/-H/sub 2/O systems, (where R=Sc, Y, La). The formation of double tungstates NH/sub 4/R(WO/sub 4/)/sub 2/xnH/sub 2/O is established. The NH/sub 4/Sc(WO/sub 4/)/sub 2/x4.5H/sub 2/O, NH/sub 4/Yx(WO/sub 4/)/sub 2/x3H/sub 2/O, NH/sub 4/La(WO/sub 4/)/sub 2/x1.5H/sub 2/O compounds are synthesized in individual form. Precipitation conditions (pH, concentration ratio) and composition of the solid phase are determined. The behaviour of synthesized slats at thermolysis up to 880 deg C is studied. Physicochemical properties (color, solubility of the simple and double tungstates of scandium, yttrium and lanthanum with ammonium) is studied. IR spectra and X-ray diffraction analysis give idea about double salts structural transformations.

  1. Analytical chemistry of lanthanides

    International Nuclear Information System (INIS)

    Al-Sowdani, K.H.

    1986-12-01

    Candoluminescence of the lanthanides and the development of instruments for monitoring the phenomenon are described. The use of fluorescence spectroscopy, spectrofluorometry and spectrophotometry for the quantitative chemical analysis of the lanthanides is described. (U.K.)

  2. Thermodynamic and kinetic study of scandium(III) complexes of DTPA and DOTA: a step toward scandium radiopharmaceuticals.

    Science.gov (United States)

    Pniok, Miroslav; Kubíček, Vojtěch; Havlíčková, Jana; Kotek, Jan; Sabatie-Gogová, Andrea; Plutnar, Jan; Huclier-Markai, Sandrine; Hermann, Petr

    2014-06-23

    Diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) scandium(III) complexes were investigated in the solution and solid state. Three (45)Sc NMR spectroscopic references suitable for aqueous solutions were suggested: 0.1 M Sc(ClO4)3 in 1 M aq. HClO4 (δSc =0.0 ppm), 0.1 M ScCl3 in 1 M aq. HCl (δSc =1.75 ppm) and 0.01 M [Sc(ox)4](5-) (ox(2-) = oxalato) in 1 M aq. K2C2O4 (δSc =8.31 ppm). In solution, [Sc(dtpa)](2-) complex (δSc = 83 ppm, Δν = 770 Hz) has a rather symmetric ligand field unlike highly unsymmetrical donor atom arrangement in [Sc(dota)](-) anion (δSc = 100 ppm, Δν = 4300 Hz). The solid-state structure of K8[Sc2(ox)7]⋅13 H2O contains two [Sc(ox)3](3-) units bridged by twice "side-on" coordinated oxalate anion with Sc(3+) ion in a dodecahedral O8 arrangement. Structures of [Sc(dtpa)](2-) and [Sc(dota)](-) in [(Hguanidine)]2[Sc(dtpa)]⋅3 H2O and K[Sc(dota)][H6 dota]Cl2⋅4 H2O, respectively, are analogous to those of trivalent lanthanide complexes with the same ligands. The [Sc(dota)](-) unit exhibits twisted square-antiprismatic arrangement without an axial ligand (TSA' isomer) and [Sc(dota)](-) and (H6 dota)(2+) units are bridged by a K(+) cation. A surprisingly high value of the last DOTA dissociation constant (pKa =12.9) was determined by potentiometry and confirmed by using NMR spectroscopy. Stability constants of scandium(III) complexes (log KScL 27.43 and 30.79 for DTPA and DOTA, respectively) were determined from potentiometric and (45)Sc NMR spectroscopic data. Both complexes are fully formed even below pH 2. Complexation of DOTA with the Sc(3+) ion is much faster than with trivalent lanthanides. Proton-assisted decomplexation of the [Sc(dota)](-) complex (τ1/2 =45 h; 1 M aq. HCl, 25 °C) is much slower than that for [Ln(dota)](-) complexes. Therefore, DOTA and its derivatives seem to be very suitable ligands for scandium

  3. Yttrium aluminum garnet coating on glass substrate

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J., E-mail: eduardo.nassar@unifran.edu.br

    2016-02-15

    Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu{sup 3+} onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min{sup −1} and evaporation led to deposition of different numbers of layers of the YAG:Eu{sup 3+} film onto the glass substrate from a YAG:Eu{sup 3+} powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu{sup 3+}. • The matrix was deposited as transparent films. • The YAG:Eu{sup 3+} was deposited by sol–gel process onto glass substrate.

  4. Yttrium aluminum garnet coating on glass substrate

    International Nuclear Information System (INIS)

    Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J.

    2016-01-01

    Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu 3+ onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min −1 and evaporation led to deposition of different numbers of layers of the YAG:Eu 3+ film onto the glass substrate from a YAG:Eu 3+ powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu 3+ . • The matrix was deposited as transparent films. • The YAG:Eu 3+ was deposited by sol–gel process onto glass substrate.

  5. Unactivated yttrium tantalate phosphor

    International Nuclear Information System (INIS)

    Reddy, V.B.; Cheung, H.K.

    1992-01-01

    This patent describes an unactivated yttrium tantalate phosphor having M prime monoclinic structure and containing one or more additives of Rb and Al in an amount of between about 0.001 to 0.1 moles per mole of yttrium tantalate to improve brightness under X-radiation. This patent also describes an unactivated yttrium tantalate phosphor having M prime monoclinic structure and containing additives of Sr in an amount of between 0.001 to 0.1 moles per mole of yttrium tantalate and one or more of Rb and Al in an amount of between 0.001 to 0.1 moles per mole of yttrium tantalate the phosphor exhibiting a greater brightness under X-radiation than the phosphor absent Rb and Al

  6. Solvent extraction of tricomponent complexes of zirconium and scandium with salicylic acid and collidine

    International Nuclear Information System (INIS)

    Kochetkova, S.K.; Fadeeva, V.I.; Kalistratova, V.P.

    1976-01-01

    Extraction of tricomponent compounds of zirconium and scandium with salicylic acid (Sal) and collidine (Col) has been studied. Addition of Col widens considerably the pH range of maximum extraction of zirconium salicylate and makes it possible to extract quantitatively both zirconium and scandium in the following pH range: scandium at pH 3.8-5.2; zirconium at pH 2-4. Optimum concentrations of salicylic acid and collidine are 0.05 mol/l and 0.375 mol/l, respectively. The composition of the complexes being extracted has been studied by the shift equilibrium method. Chloroform extracts complexes having the ratio Zr:Sal:Col=1:2:1(pH=3); Sc:Sal:Col=1:3:1(pH=4), and 1:2:1(pH=5). The composition of the complexes being formed is assumed to be [Zr(OH) 3 (HSal) 2 ] - [ColH + ] (pH=3); Sc(HSal) 3 xCol (pH=4.0); Sc(OH)(HSal) 2 xCol (pH=5.0). Extraction of collidine-salicylate complexes of Hf, Th, La, and Y under the conditions of optimum extraction of zirconium and scandium has been investigated when concentration of Zr and Sc in the solution is 3.0.10μ- 5 -1.37.10 -4 mol/l, respectively. It has been shown that hafnium is extracted quantitatively (95-100%) at pH 2.3-4.6; thorium at pH 3.0-6.4; 60% of yttrium is extracted at pH 4.0-4.8; 25% of lanthanum is extracted at pH 3.3-4.9. At pH 2.0 it is possible to separate Zr from Sc,Y, and La; at pH 1.4-1.5 from small amounts of Hf and Tn. Separation of zirconium, from small amounts of hafnium, 10-fold amounts of thorium, 100-fold amounts of scandium and lanthanum is also possible

  7. Solvent extraction of tricomponent complexes of zirconium and scandium with salicylic acid and collidine

    Energy Technology Data Exchange (ETDEWEB)

    Kochetkova, S K; Fadeeva, V I; Kalistratova, V P [Moskovskij Gosudarstvennyj Univ. (USSR)

    1976-01-01

    Extraction of tricomponent compounds of zirconium and scandium with salicylic acid (Sal) and collidine (Col) has been studied. Addition of Col widens considerably the pH range of maximum extraction of zirconium salicylate and makes it possible to extract quantitatively both zirconium and scandium in the following pH range: scandium at pH 3.8-5.2; zirconium at pH 2-4. Optimum concentrations of salicylic acid and collidine are 0.05 mol/l and 0.375 mol/l, respectively. The composition of the complexes being extracted has been studied by the shift equilibrium method. Chloroform extracts complexes having the ratio Zr:Sal:Col=1:2:1(pH=3); Sc:Sal:Col=1:3:1(pH=4), and 1:2:1(pH=5). The composition of the complexes being formed is assumed to be (Zr(OH)/sub 3/(HSal)/sub 2/)/sup -/(ColH/sup +/) (pH=3); Sc(HSal)/sub 3/xCol (pH=4.0); Sc(OH)(HSal)/sub 2/xCol (pH=5.0). Extraction of collidine-salicylate complexes of Hf, Th, La, and Y under the conditions of optimum extraction of zirconium and scandium has been investigated when concentration of Zr and Sc in the solution is 3.0.10..mu..-/sup 5/-1.37.10/sup -4/ mol/l, respectively. It has been shown that hafnium is extracted quantitatively (95-100%) at pH 2.3-4.6; thorium at pH 3.0-6.4; 60% of yttrium is extracted at pH 4.0-4.8; 25% of lanthanum is extracted at pH 3.3-4.9. At pH 2.0 it is possible to separate Zr from Sc,Y, and La; at pH 1.4-1.5 from small amounts of Hf and Tn. Separation of zirconium, from small amounts of hafnium, 10-fold amounts of thorium, 100-fold amounts of scandium and lanthanum is also possible.

  8. Thermodecomposition of lanthanides (III) and ytrium (III) glucoheptonates

    International Nuclear Information System (INIS)

    Giolito, J.

    1987-01-01

    The lanthanides (III) and yttrium (III) glucoheptonates as well the D-glucoheptono 1-4 lactone were studied using common analytical methods, elemental microanalysis of carbon and hydrogen, thermogravimetry and differential scanning calorimetry. These compounds were prepared from the reaction between the lanthanides (III) and yttrium (III) hydroxides and glucoheptonic acid aqueous solution obtained by means of the delta lactone hydrolysis of this acid. After stoichiometric reaction the compounds were precipitated by the addition of absolute ethanol, washed with the same solvent and dried in desiccator. Thermogravimetric the (TG) curves of the lanthanides glucoheptonates of the ceric group present thermal profiles with enough differences permitting an easy caracterization of each compound and the yttrium (III) glucoheptonate TG curve showed a great similarity with the erbium (III) compound TG curve. The differential scanning calometry (DSC) curves showed endothermic and exothermic peaks by their shape, height and position (temperature) permit an easy and rapid identification of each compound specially if DSC and TG curves were examined simultaneously. (author) [pt

  9. Complexometric determination of scandium and aluminium

    International Nuclear Information System (INIS)

    Tikhonov, V.N.

    1980-01-01

    Described is the complexometric determination of scandium and aluminium by the method of reverse titration of EDTA excess by indium salt solution in the presence of the xylenol orange indicator. For the method selectivity increase fluorides are used as a camouflage substance at low pH values (2.5-3.0). The excess fluoride-ions preventing titration are bound by boric acid. Y, Tb, Ti, Zr, Cu, Zn, V, Mo, Co, Cr prevent the determination of Sc and Al

  10. Diffusion of hydrogen in yttrium

    International Nuclear Information System (INIS)

    Vorobyov, V.V.; Ryabchikov, L.N.

    1966-01-01

    In this work the diffusion coefficients of hydrogen in yttrium were determined from the rate at which the hydrogen was released from yttrium samples under a vacuum at temperatures of 450 to 850 0 C and from the quantity of hydrogen retained by yttrium at hydrogen pressures below 5 x 10 - 4 mm Hg in the same temperature range

  11. PIXE analysis of tumors and localization behavior of a lanthanide in nude mice

    Science.gov (United States)

    Chang, Pei-Jiun; Yang, Czau-Siung; Chou, Ming-Ji; Wei, Chau-Chin; Hsu, Chu-Chung; Wang, Chia-Yu

    1984-04-01

    We have used particle induced X-ray emission (PIXE) to analyze the elemental compositions and uptakes of a lanthanide, yttrium in this report, in tumors and normal tissues of nude mice. A small amount of yttrium nitrate was injected into nude mice with tumors. Samples of normal and malignant tissues taken from these mice were bombarded by the 2 MeV proton beam from a 3 MeV Van de Graaff accelerator with a Ge detector system to determine the relative elemental compositions of tissues and the relative concentrations of yttrium taken up by these tissues. We found that the uptakes of yttrium by tumors were at least five times more than those by normal tissues. Substantial differences were often observed between the trace element weight (or concentration) pattern of the cancerous and normal tissues. The present result is compared with human tissues.

  12. The Lanthanide Contraction Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, Michael; Oliver, Allen G.; Raymond, Kenneth N.

    2007-04-19

    A complete, isostructural series of lanthanide complexes (except Pm) with the ligand TREN-1,2-HOIQO has been synthesized and structurally characterized by means of single-crystal X-ray analysis. All complexes are 1D-polymeric species in the solid state, with the lanthanide being in an eight-coordinate, distorted trigonal-dodecahedral environment with a donor set of eight unique oxygen atoms. This series constitutes the first complete set of isostructural lanthanide complexes with a ligand of denticity greater than two. The geometric arrangement of the chelating moieties slightly deviates across the lanthanide series, as analyzed by a shape parameter metric based on the comparison of the dihedral angles along all edges of the coordination polyhedron. The apparent lanthanide contraction in the individual Ln-O bond lengths deviates considerably from the expected quadratic decrease that was found previously in a number of complexes with ligands of low denticity. The sum of all bond lengths around the trivalent metal cation, however, is more regular, showing an almost ideal quadratic behavior across the entire series. The quadratic nature of the lanthanide contraction is derived theoretically from Slater's model for the calculation of ionic radii. In addition, the sum of all distances along the edges of the coordination polyhedron show exactly the same quadratic dependency as the Ln-X bond lengths. The universal validity of this coordination sphere contraction, concomitant with the quadratic decrease in Ln-X bond lengths, was confirmed by reexamination of four other, previously published, almost complete series of lanthanide complexes. Due to the importance of multidentate ligands for the chelation of rare-earth metals, this result provides a significant advance for the prediction and rationalization of the geometric features of the corresponding lanthanide complexes, with great potential impact for all aspects of lanthanide coordination.

  13. Ternary scandium and transition metals germanides

    International Nuclear Information System (INIS)

    Kotur, B.Ya.

    1992-01-01

    Brief review of data on phase diagram of ternary Sc-Me-Ge systems (Me-d - , f-transition element) is given. Isothermal sections at 870 and 1070 K of 17 ternary systems are plotted. Compositions and their structural characteristics are presented. Variability of crystal structure is typical for ternary scandium germanides: 70 compounds with the studied structure belong to 23 structural types. Ternary germanides isostructural to types of Sm 4 Ge 4 , ZrCrSi 2 , ZrNiAl, ScCeSi, TiNiSi U 4 Re 7 Si 6 145 compounds from 70 under investigation are mostly formed in studied systems

  14. Extraction of scandium salicylate by tetraethyldiamidoheptyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Kamenev, V F; Fadeeva, V I; Zyk, N V [Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Analiticheskoj Khimii

    1976-11-01

    Scandium salicylate is extracted with chloroform in a narrow pH range 3-4 and at the maximum concentration of salicylic acid (H/sub 2/A) in an organic phase, the distribution coefficient reaches 0.1. In the presence of tetraethyldiamideheptylphosphate (DAHP) the zone of maximum extraction grows and the distribution coefficient increases. The ratio of the components in the complex extracted is Sc:H/sub 2/A:DAHPh=1:3:2. The extraction constant is Ksub(ex)=(2.00+-0.02).

  15. Lanthanide single molecule magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jinkui; Zhang, Peng [Chinese Academy of Sciences, Changchun (China). Changchun Inst. of Applied Chemistry

    2015-10-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures - an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and explore new directions.

  16. Lanthanide single molecule magnets

    CERN Document Server

    Tang, Jinkui

    2015-01-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs, and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures – an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and...

  17. Recovery of lanthanides

    International Nuclear Information System (INIS)

    Tilley, G.L.; Doyle, W.E.

    1990-01-01

    This paper discusses a method for recovering a lanthanide and thorium from a material containing a fluorine compound and the lanthanide and thorium. It comprises a. obtaining the material from a roasted, acid-leached bastnasite ore; b. forming a mixture of the material with at least about ten weight percent of silica; c. contacting the mixture with sulfuric acid; d. heating the mixture and sulfuric acid to a temperature of at least about 150 degrees C for at least about 3 hours to cause most of the fluorine to be released as a volatile material containing silicon and fluorine; e. contacting the reacted mixture with an aqueous medium consisting essentially of water to solubilize the lanthanide and thorium while leaving an insoluble residue; and f. separating the aqueous solution of the lanthanide and thorium from the insoluble residue

  18. Addition compounds of lanthamide (III) and yttrium (III) hexafluorophosphates and N,N - dimethylformamide

    International Nuclear Information System (INIS)

    Braga, L.S.P.

    1983-01-01

    Addition compounds of lanthanide (III) and yttrium (III) hexafluorophosphates and N-N-Dimetylformamide are described to characterize the complexes, elemental analysis, melting ranges, molar conductance measurements, X-ray powder patters infrared and Raman spectra, TG and DTA curves, are studied. Information concerning the decomposition of the adducts through the thermogravimetric curves and the differential thermal analysis curves is obtained. (M.J.C.) [pt

  19. Dissolution of lanthanide alumino-silicate oxynitride glasses

    Science.gov (United States)

    Bois, L.; Barré, N.; Guillopé, S.; Guittet, M. J.; Gautier-Soyer, M.; Duraud, J. P.; Trocellier, P.; Verdier, P.; Laurent, Y.

    2000-01-01

    The aqueous corrosion behavior of lanthanide aluminosilicate glasses has been studied under static conditions ( T=96°C, duration=1 and 3 months, glass surface area/leachate volume, S/ V=0.3 cm -1) by means of solution and solid analyses. It was found that these glasses exhibit a high chemical durability. The influence of yttrium, magnesium and nitrogen, which are supposed to improve the mechanical properties, on the chemical durability, has been investigated. After a one-month experiment, lanthanum and yttrium releases were found to be about 10 -7 mol l -1, while silicon and aluminum releases were about 10 -5 mol l -1. Yttrium seems to improve the chemical durability. The presence of nitrogen does not seem to modify the glass constituents releases, but seems to improve the surface state of the altered glass. XPS experiments reveal that lanthanum and yttrium are more concentrated near the surface (20-30 Å) of the glass after the leaching test.

  20. Lanthanoid and yttrium tellurates

    Energy Technology Data Exchange (ETDEWEB)

    Gonalez, C G; Guedes de Carvalho, R A [Faculdade de Engenharia, Porto (Portugal). Centro de Engenharia Quimica

    1978-05-01

    Preparation in aqueous medium of all the lanthanoid (except Ce and Pm) and yttrium tellurates is described. Chemical analyses, solubilities at 25/sup 0/C in water and thermograms of all the products prepared were determined. X-ray diffractograms and DTA and DTG curves of La, Gd and Yb tellurates were obtained and commented. Partial volatilization of lanthanoid is observed in the thermal analysis of tellurates.

  1. Scandium: its occurrence, chemistry, physics, metallurgy, biology, and technology

    International Nuclear Information System (INIS)

    Horovitz, C.T.

    1975-01-01

    This book describes the following aspects of scandium: discovery and history, occurrence in nature, geochemistry and mineralogy, chemical, physical and technological properties, fabrication and metallurgy, its biological significance and toxicology, and its uses. (Extensive references for each chapter)

  2. Interaction of scandium sesquioxide with carbon

    International Nuclear Information System (INIS)

    Vodop'yanov, A.G.; Zakharov, R.G.

    1986-01-01

    In the range of 2350-2470 degrees K at a PCO = 0.0 MPa, interaction in Sc 2 O 3 with carbon mixtures initially occurs by CO chemisorption at the scandium oxide surface and disproportionation into CO 2 and C, with subsequent replacement of oxygen in the oxide anion sublattice by carbon to form ScC. The carbide melt, creating a contact between the reagents, then transforms the process to a diffusion-based one. At 1820-2220 K in vacuum, reduction of the studied mixtures occurs by dissociative vaporization of the oxide, with precipitation of ScC at the carbon surface and generation of CO. The appearance of CO in the vapors of mixture leads to formation of an oxycarbide phase and to the partial occurrence of oxide dissociation

  3. The crystal structure of scandium dyhydrate triglycolate

    International Nuclear Information System (INIS)

    Dukareva, L.M.; Antishkina, A.S.; Porai-Koshits, M.A.; Ostrikova, V.N.; Arkhangel'skij, I.V.; Amanov, A.Z.

    1978-01-01

    The structure of colorless crystals of scandium glycolate dehydrate Sc(CH 2 OHCOO) 3 x2H 2 O, synthesized at the chemical department of MSU has been investigated. Parameters of the monoclinic lattice are determined according to roentgenograms of swing and Kforograms and are specified using the DRON-1 diffractor: a=14.624-+0.005 A; b=13.052-+0.003 A; c=5.730+-0.003 A; γ=96.26 deg+-0.01 deg; rhosub(exper.)=1.09 g/cm 3 ; Z=4; Sp.=P 2/b. Experimental photographic data are obtained using the KFOR chamber. Scannings of the layer lines h anti Ko-h anti K4, containing 742 independent reflexes are taken. Deciphering of the structure is carried out by means of analysis of the Paterson functions distribution and conventional and differential electron densities. Description of the system is presented

  4. Effects of erbium‑and chromium‑doped yttrium scandium gallium ...

    African Journals Online (AJOL)

    2014-08-21

    Aug 21, 2014 ... The Er, Cr: YSGG laser also caused deep defects on composite, compomer, and RMGIC ... In amalgam samples, neither laser left significant harmful effects at the ..... The Er, Cr: YSGG laser left shallow irradiation markings.

  5. Lanthanide metal-organic frameworks

    International Nuclear Information System (INIS)

    Cheng, Peng

    2015-01-01

    This book contains the following nine chapters: lanthanide metal-organic frameworks: syntheses, properties, and potential applications (Stephen Fordham, Xuan Wang, Mathieu Bosch, Hong-Cai Zhou); 2. chiral lanthanide metal-organic frameworks (Weisheng Liu, Xiaoliang Tang); 3. Porous lanthanide metal-organic frameworks for gas storage and separation (Bin Li, Banglin Chen); 4. Luminescent lanthanide metal-organic frameworks (Xue-Zhi Song, Shu-Yan Song, Hong-Jie Zhang); 5. Metal-organic frameworks based on lanthanide clusters (Lian Chen, Feilong Jiang, Kang Zhou, Mingyan Wu, Maochun Hong); 6. metal-organic frameworks with d-f cyanide bridges: structural diversity, bonding regime, and magnetism (Marilena Ferbinteanu, Fanica Cimpoesu, Stefania Tanase); 7. transition-lanthanide heterometal-organic frameworks: synthesis, structures, and properties (Wei Shi, Ke Liu, Peng Cheng); 8: MOFs of uranium and the actinides (Juan Su, Jiesheng Chen); 9. Nanostructured and/or nanoscale lanthanide metal-organic frameworks (Zhonghao Zhang, Zhiping Zheng).

  6. Lanthanide metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Peng (ed.) [Nankai Univ., Tianjin (China). Dept. of Chemistry

    2015-03-01

    This book contains the following nine chapters: lanthanide metal-organic frameworks: syntheses, properties, and potential applications (Stephen Fordham, Xuan Wang, Mathieu Bosch, Hong-Cai Zhou); 2. chiral lanthanide metal-organic frameworks (Weisheng Liu, Xiaoliang Tang); 3. Porous lanthanide metal-organic frameworks for gas storage and separation (Bin Li, Banglin Chen); 4. Luminescent lanthanide metal-organic frameworks (Xue-Zhi Song, Shu-Yan Song, Hong-Jie Zhang); 5. Metal-organic frameworks based on lanthanide clusters (Lian Chen, Feilong Jiang, Kang Zhou, Mingyan Wu, Maochun Hong); 6. metal-organic frameworks with d-f cyanide bridges: structural diversity, bonding regime, and magnetism (Marilena Ferbinteanu, Fanica Cimpoesu, Stefania Tanase); 7. transition-lanthanide heterometal-organic frameworks: synthesis, structures, and properties (Wei Shi, Ke Liu, Peng Cheng); 8: MOFs of uranium and the actinides (Juan Su, Jiesheng Chen); 9. Nanostructured and/or nanoscale lanthanide metal-organic frameworks (Zhonghao Zhang, Zhiping Zheng).

  7. Lifetime measurements and oscillator strengths in singly ionized scandium and the solar abundance of scandium

    Science.gov (United States)

    Pehlivan Rhodin, A.; Belmonte, M. T.; Engström, L.; Lundberg, H.; Nilsson, H.; Hartman, H.; Pickering, J. C.; Clear, C.; Quinet, P.; Fivet, V.; Palmeri, P.

    2017-12-01

    The lifetimes of 17 even-parity levels (3d5s, 3d4d, 3d6s and 4p2) in the region 57 743-77 837 cm-1 of singly ionized scandium (Sc II) were measured by two-step time-resolved laser induced fluorescence spectroscopy. Oscillator strengths of 57 lines from these highly excited upper levels were derived using a hollow cathode discharge lamp and a Fourier transform spectrometer. In addition, Hartree-Fock calculations where both the main relativistic and core-polarization effects were taken into account were carried out for both low- and high-excitation levels. There is a good agreement for most of the lines between our calculated branching fractions and the measurements of Lawler & Dakin in the region 9000-45 000 cm-1 for low excitation levels and with our measurements for high excitation levels in the region 23 500-63 100 cm-1. This, in turn, allowed us to combine the calculated branching fractions with the available experimental lifetimes to determine semi-empirical oscillator strengths for a set of 380 E1 transitions in Sc II. These oscillator strengths include the weak lines that were used previously to derive the solar abundance of scandium. The solar abundance of scandium is now estimated to logε⊙ = 3.04 ± 0.13 using these semi-empirical oscillator strengths to shift the values determined by Scott et al. The new estimated abundance value is in agreement with the meteoritic value (logεmet = 3.05 ± 0.02) of Lodders, Palme & Gail.

  8. Yttrium-90 - ED 4310

    International Nuclear Information System (INIS)

    Ammerich, M.; Frot, P.; Gambini, D.; Gauron, C.; Moureaux, P.; Herbelet, G.; Lahaye, T.; Pihet, P.; Rannou, A.; Vidal, E.

    2013-03-01

    This sheet presents the characteristics of yttrium-90, its origin, and its radio-physical and biological properties. It briefly describes its use in nuclear medicine. It indicates its dosimetric parameters for external exposure, cutaneous contamination, and internal exposure due to acute contamination or to chronic contamination. It indicates and comments the various exposure control techniques: ambient dose rate measurement, surface contamination measurement, atmosphere contamination. It addresses the means of protection: premise design, protection against external exposure and against internal exposure. It describes how areas are delimited and controlled within the premises: regulatory areas, controls to be performed. It addresses the personnel classification, training and medical survey. It addresses the issue of solid and liquid wastes and liquid or gaseous effluents. It briefly recalls the administrative procedures related to the authorization and declaration of possession and use of sealed and unsealed sources. It indicates regulatory aspects related to the transport of yttrium-90, describes what is to be done in case of incident or accident (for the different types of contamination or exposure)

  9. Hot-pressed silicon nitride with various lanthanide oxides as sintering additives

    Science.gov (United States)

    Ueno, K.; Toibana, Y.

    1984-01-01

    The effects of addition of various lanthanide oxides and their mixture with Y2O3 on the sintering of Si3N4 were investigated. The addition of simple and mixed lanthanide oxides promoted the densification of Si3N4 in hot-pressing at 1800 C under 300-400kg/ centimeters squared for 60 min. The crystallization of yttrium and lanthanide-silicon oxynitrides which was observed inn the sintered body containing yttrium-lanthanide mixed oxides as additives led to the formation of a highly refractory Si3N4 ceramic having a bending strength of 82 and 84 kg/millimeters squared at room temperature and 1300 C respectively. In a Y2O3+La2O3 system, a higher molar ratio of La2O3 to Y2O3 gave a higher hardness and strength at high temperatures. It was found that 90 min was an optimum sintering time for the highest strength.

  10. Highly sensitive luminescence method of scandium determination in the products of metallurgical reprocessing

    International Nuclear Information System (INIS)

    Matveets, M.A.; Akhmetova, S.D.

    1988-01-01

    Highly sensitive reaction of scandium with 1,10-phenanthroline and eosin is used for the development of luminescence method of its determination in metallurgical products. The effect of interfering elements is eliminated by scandium extraction with monocarboxylic acids. The method permits to determine scandium content from 5 x 10 -5 % (Sr 0.15 - 0.25)

  11. Luminescent lanthanide coordination polymers

    Energy Technology Data Exchange (ETDEWEB)

    Ma, L.; Evans, O.R.; Foxman, B.M.; Lin, W.

    1999-12-13

    One-dimensional lanthanide coordination polymers with the formula Ln(isonicotinate){sub 3}(H{sub 2}O){sub 2} (Ln = Ce, Pr, Nd, Sm, Eu, Tb; 1a-f) were synthesized by treating nitrate or perchlorate salts of Ln(III) with 4-pyridinecarboxaldehyde under hydro(solvo)thermal conditions. Single-crystal and powder X-ray diffraction studies indicate that these lanthanide coordination polymers adopt two different structures. While Ce(III), Pr(III), and Nd(III) complexes adopt a chain structure with alternating Ln-(carboxylate){sub 2}-Ln and Ln-(carboxylate){sub 4}-Ln linkages, Sm(III), Eu(III), and Tb(III) complexes have a doubly carboxylate-bridged infinite-chain structure with one chelating carboxylate group on each metal center. In both structures, the lanthanide centers also bind to two water molecules to yield an eight-coordinate, square antiprismatic geometry. The pyridine nitrogen atoms of the isonicotinate groups do not coordinate to the metal centers in these lanthanide(III) complexes; instead, they direct the formation of Ln(III) coordination polymers via hydrogen bonding with coordinated water molecules. Photoluminescence measurements show that Tb(isonicotinate){sub 3}(H{sub 2}O){sub 2} is highly emissive at room temperature with a quantum yield of {approximately}90%. These results indicate that highly luminescent lanthanide coordination polymers can be assembled using a combination of coordination and hydrogen bonds. Crystal data for 1a: monoclinic space group P2{sub 1}/c, a = 9.712(2) {angstrom}, b = 19.833(4) {angstrom}, c = 11.616(2) {angstrom}, {beta} = 111.89(3){degree}, Z = 4. Crystal data for 1f: monoclinic space group C2/c, a = 20.253(4) {angstrom}, b = 11.584(2) {angstrom}, c = 9.839(2) {angstrom}, {beta} = 115.64(3){degree}, Z = 8.

  12. Size Effects on Deformation and Fracture of Scandium Deuteride Films.

    Energy Technology Data Exchange (ETDEWEB)

    Teresi, C. S. [Univ. of Minnesota, Minneapolis, MN (United States); Hintsala, E. [Univ. of Minnesota, Minneapolis, MN (United States); Hysitron, Inc., Eden Prairie, MN (United States); Adams, David P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yang, Nancy Y. C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kammler, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moody, N. R. [Univ. of Minnesota, Minneapolis, MN (United States); Gerberich, W. W. [Univ. of Minnesota, Minneapolis, MN (United States)

    2017-07-01

    Metal hydride films have been observed to crack during production and use, prompting mechanical property studies of scandium deuteride films. The following focuses on elastic modulus, fracture, and size effects observed in the system for future film mechanical behavior modeling efforts. Scandium deuteride films were produced through the deuterium charging of electron beam evaporated scandium films using X-ray diffraction, scanning Auger microscopy, and electron backscatter diffraction to monitor changes in the films before and after charging. Scanning electron microscopy, nanoindentation, and focused ion beam machined micropillar compression tests were used for mechanical characterization of the scandium deuteride films. The micropillars showed a size effect for flow stress, indicating that film thickness is a relevant tuning parameter for film performance, and that fracture was controlled by the presence of grain boundaries. Elastic modulus was determined by both micropillar compression and nanoindentation to be approximately 150 GPa, Fracture studies of bulk film channel cracking as well as compression induced cracks in some of the pillars yielded a fracture toughness around 1.0 MPa-m1/2. Preliminary Weibull distributions of fracture in the micropillars are provided. Despite this relatively low value of fracture toughness, scandium deuteride micropillars can undergo a large degree of plasticity in small volumes and can harden to some degree, demonstrating the ductile and brittle nature of this material

  13. Triheterometallic Lanthanide Complexes Prepared from Kinetically Inert Lanthanide Building Blocks

    DEFF Research Database (Denmark)

    Sørensen, Thomas Just; Tropiano, Manuel; Kenwright, Alan M.

    2017-01-01

    Three molecular structures, each containing three different lanthanide(III) centres, have been prepared by coupling three kinetically inert lanthanide(III) complexes in an Ugi reaction. These 2 kDa molecules were purified by dialysis and characterised by NMR and luminescence techniques. The photo...... and lanthanide(III) centres in these molecules inhibits the efficient sensitisation of europium. We conclude that the intramolecular collisions required for efficient Dexter energy transfer from the sensitiser to the lanthanide(III) centre can be prevented by steric congestion....

  14. Formation of scandium carbides and scandium oxycarbide from the elements at high-(P, T) conditions

    International Nuclear Information System (INIS)

    Juarez-Arellano, Erick A.; Winkler, Bjoern; Bayarjargal, Lkhamsuren; Friedrich, Alexandra; Milman, Victor; Kammler, Daniel R.; Clark, Simon M.; Yan Jinyuan; Koch-Mueller, Monika; Schroeder, Florian; Avalos-Borja, Miguel

    2010-01-01

    Synchrotron diffraction experiments with in situ laser heated diamond anvil cells and multi-anvil press synthesis experiments have been performed in order to investigate the reaction of scandium and carbon from the elements at high-(P,T) conditions. It is shown that the reaction is very sensitive to the presence of oxygen. In an oxygen-rich environment the most stable phase is ScO x C y , where for these experiments x=0.39 and y=0.50-0.56. If only a small oxygen contamination is present, we have observed the formation of Sc 3 C 4 , Sc 4 C 3 and a new orthorhombic ScC x phase. All the phases formed at high pressures and temperatures are quenchable. Experimentally determined elastic properties of the scandium carbides are compared to values obtained by density functional theory based calculations. - Graphical Abstract Legend (TOC Figure): Table of Contents Figure Selected images recorded with a MAR345 image plate detector show the reaction of α-Sc and graphite at high-(P,T) conditions. Left: mixture of α-Sc and graphite. Right: recovered sample after laser heated the diamond anvil cell.

  15. Smelting of Scandium by Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Satoshi Fujii

    2017-09-01

    Full Text Available Scandium is being explored as an alloying element for aluminum alloys, which are gaining importance as high-performance lightweight structural alloys in the transportation industry. A few years ago, Sc was also found to be suitable for use in electrical devices. High-Sc-content ScAlN thin films have attracted significant attention because of their strong piezoelectricity. The piezoelectric response of ScAlN suggests that ScAlN thin films formed on a hard substrate would be suitable surface acoustic wave wideband filters for next-generation wireless communication systems. However, it is often difficult to use ScAlN thin films in MEMS devices—including acoustic ones—because of the extremely high price of metallic Sc, given the difficulty associated with smelting it. Here, we propose a novel process for smelting Sc metal by microwave irradiation. Sc metal was able to be obtained successfully from ScF3 through a microwave-irradiation-based carbon reduction reaction. The reaction temperature for this reduction process was approximately 880°C, which is half of that for the conventional smelting process involving reduction with Ca. Thus, the proposed microwave irradiation process has significant potential for use in the smelting of Sc metal.

  16. Scandium and zirconium ion complexing with salicylic acid

    International Nuclear Information System (INIS)

    Fadeeva, V.I.; Kochetkova, S.K.

    1979-01-01

    A study has been made of the extraction of complexes containing scandium and zirconium compounds and salicylic acid by using benzene, nitrobenzene, chloroform and isoamyl alcohol. It is shown that in the metal concentration range 10 -5 -10 -3 mole/l scandium forms mononuclear complexes composed of Sc(HSal) 3 (pH 2 (pH>4), zirconium - polynuclear complexes Zrsub(x)(OH)sub(y)(HSal)sub(n), where the x:n ratio varies from 0.5 to 1.5. Stability constants have been calculated for the salicylate scandium complexes in aqueous solution, equal to β 1 =(3+-1)x10 2 ; β 2 =(5.0+-0.6)x10 4 ; β 3 =(5.3+-0.3)x10 6

  17. Scandium and zirconium ion complexing with salicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Fadeeva, V I; Kochetkova, S K [Moskovskij Gosudarstvennyj Univ. (USSR)

    1979-08-01

    A study has been made of the extraction of complexes containing scandium and zirconium compounds and salicylic acid by using benzene, nitrobenzene, chloroform and isoamyl alcohol. It is shown that in the metal concentration range 10/sup -5/-10/sup -3/ mole/l scandium forms mononuclear complexes composed of Sc(HSal)/sub 3/ (pH<=4) and Sc(OH)(HSal)/sub 2/ (pH>4), zirconium - polynuclear complexes Zrsub(x)(OH)sub(y)(HSal)sub(n), where the x:n ratio varies from 0.5 to 1.5. Stability constants have been calculated for the salicylate scandium complexes in aqueous solution, equal to ..beta../sub 1/=(3+-1)x10/sup 2/; ..beta../sub 2/=(5.0+-0.6)x10/sup 4/; ..beta../sub 3/=(5.3+-0.3)x10/sup 6/.

  18. RARE EARTH ELEMENTS: A REVIEW OF PRODUCTION, PROCESSING, RECYCLING, AND ASSOCIATED ENVIRONMENTAL ISSUES

    Science.gov (United States)

    Rare earth elements (REEs) are a group of 15 chemical elements in the periodic table, specifically the lanthanides. Two other elements, scandium and yttrium, have a similar physiochemistry to the lanthanides, are commonly found in the same mineral assemblages, and are often refe...

  19. Valencies of the lanthanides

    OpenAIRE

    Johnson, David A.; Nelson, Peter G.

    2018-01-01

    The valencies of the lanthanides vary more than was once thought. In addition to valencies associated with a half-full shell, there are valencies associated with a quarter- and three-quarter-full shell. This can be explained on the basis of Slater’s theory of many-electron atoms. The same theory explains the variation in complexing constants in the trivalent state (the “tetrad effect”). Valency in metallic and organometallic compounds is also discussed.

  20. Yttrium and lanthanum recovery from low cerium carbonate, yttrium carbonate and yttrium concentrate

    International Nuclear Information System (INIS)

    Vasconcelos, Mari Estela de

    2006-01-01

    In this work, separation, enrichment and purification of lanthanum and yttrium were performed using as raw material a commercial low cerium rare earth concentrate named LCC (low cerium carbonate), an yttrium concentrate named 'yttrium carbonate', and a third concentrated known as 'yttrium earths oxide. The first two were industrially produced by the late NUCLEMON - NUCLEBRAS de Monazita e Associados Ltda, using Brazilian monazite. The 'yttrium earths oxide' come from a process for preparation of lanthanum during the course of the experimental work for the present thesis. The following techniques were used: fractional precipitation with urea; fractional leaching of the LCC using ammonium carbonate; precipitation of rare earth peroxycarbonates starting from the rare earth complex carbonates. Once prepared the enriched rare earth fractions the same were refined using the ion exchange chromatography with strong cationic resin without the use of retention ion and elution using the ammonium salt of ethylenediaminetetraacetic acid. With the association of the above mentioned techniques were obtained pure oxides of yttrium (>97,7%), lanthanum (99,9%), gadolinium (96,6%) and samarium (99,9%). The process here developed has technical and economic viability for the installation of a large scale unity. (author)

  1. Coordination chemistry of several radius-sensitive complexones and applications to lanthanide-actinide separations

    Energy Technology Data Exchange (ETDEWEB)

    Potter, M.W.

    1981-10-01

    The relationships between the lanthanide complex formation equilibria and the lanthanide-actinide separation application of three radius sensitive ligands have been studied. The consecutive stepwise formation constants of the 1:1, 2:1, and 3:1 chelate species formed by the interaction of DHDMB and the tripositive lanthanides and yttrium were determined potentiometrically at 0.1 M ionic strength and 25/sup 0/C. Results indicate that three different coordination modes, one tridentate and two bidentate are in evidence. Tracer level /sup 241/Am - /sup 155/Eu cation-exchange experiments utilizing DHDMB eluents indicate that this dihydroxycarboxylate does not form a sufficiently strong americium complex to elute that actinide ahead of europium. The overall stability of the americium 3:1 complex appears intermediate between samarium and europium. Cation-exchange elutions of /sup 241/Am, /sup 155/Eu, and /sup 160/Tb mixtures with EEDTA solutions prove that the EEDTA ligand is capable of eluting americium ahead of all of the tripositive lanthanide cations. The minimum separation occurs with terbium, where the Am-Tb separation factor is 1.71. 1,5-diaminopentane-N,N,N',N'-tetraacetic acid (PMDTA) was synthesized using cation exchange. A mathematical method was developed for the formation constants of the protonated and unprotonated lanthanide-PMDTA complexes from potentiometry. Cation-exchange elutions of tracer quantities of Am, Eu, and Tb revealed that terbium is eluted ahead of both americium and europium.

  2. Scandium/carbon filters for soft x rays

    NARCIS (Netherlands)

    Artioukov, IA; Kasyanov, YS; Kopylets, IA; Pershin, YP; Romanova, SA

    2003-01-01

    This Note deals with thin-film soft x-ray filters for operation at the wavelengths near carbon K edge (similar to4.5 nm). The filters were fabricated by magnetron sputtering deposition of thin layers of scandium (total thickness 0.1-0.2 mum) onto films of polypropylene (thickness 1.5 mum) and

  3. Heat capacity and solid solubility of iron in scandium

    International Nuclear Information System (INIS)

    Tsang, T.-W.E.

    1981-01-01

    The maximum solid solubility of iron in scandium was determined to be between 50 and 85 at.ppm in the as-cast condition. As the concentration of iron increases, it segregates along the grain boundary, as is evident from optical metallography and electron microprobe examinations. Annealing also causes the iron dissolved in scandium to separate out and cluster along the grain boundary. Heat capacity measurements show an anomaly in the C/T versus T 2 plots for iron concentrations of 19 at.ppm or greater. For iron dissolved in solid scandium the excess entropy due to the iron impurity is in agreement with the theoretical prediction of ck ln(2S + 1) for an impurity-conduction electron (Kondo) interaction, but is 4 - 8 times larger than the theoretical prediction when iron segregates along the grain boundary. Furthermore, our results suggest that most of the previously reported low temperature physical properties of scandium are probably in error because of either iron impurity-conduction electron interactions or Fe-Fe interactions in the precipitated second-phase Sc-Fe compound. (Auth.)

  4. Thermoelectric material comprising scandium doped zinc cadmium oxide

    DEFF Research Database (Denmark)

    2016-01-01

    There is presented a composition of scandium doped Zinc Cadmium Oxide with the general formula ZnzCdxScyO which the inventors have prepared, and for which material the inventors have made the insight that it is particularly advantageous as an n-type oxide material, such as particularly advantageous...

  5. Synthesis and properties of scandium ortho-phosphate

    International Nuclear Information System (INIS)

    Eshchenko, L.S.; Pechkovskij, V.V.; Dvoskina, R.N.

    1979-01-01

    With the aim to elucidate the influence of synthesis conditions on the chemical composition and properties of orthophosphates of scandium, the interaction of orthophosphoric acid and scandium-containing component (oxide or salt) was studied under various conditions. In the interaction of scandium salt, phosphoric acid and ammonia at room temperature and pH 3.0; 5.0; 7.0 and 9.0 amorphous scandium phosphates have been obtained with the composition of x Sc 2 O 3 xY P 2 O 5 xz NH 3 xn H 2 O. After prolonged staying in mother liquor, roentgenoamorphous precipitates of phosphates transform into the crystalline state. The dependences are studied of the specific surface of amorphous phosphates on pH of precipitation and temperature of the heat treatment (200-800 deg C). Precipitates obtained in a neutral medium at 400 deg C temperature of thermal treatment, show a maximum specific surface. At a temperature of 820-840 deg C the crystallization of amorphous phase occurs followed by the recrystallization and formation of anhydrous SePO 4 of zircon type

  6. Preparation of polycrystalline lithium-yttrium fluoride for subsequent mono crystallization

    International Nuclear Information System (INIS)

    Kowalczyk, E.; Radomski, J.; Diduszko, R.; Iwanejko, J.; Kowalczyk, Z.; Grasza, K.

    1994-01-01

    High purity lithium-yttrium (YLF) doped with rare earth elements (Nd, Pr, Ho or Tm) was obtained in a two-stage synthesis consisting of (1) reaction of ammonium fluoride with a mixture of lithium carbonate, yttrium oxide, and oxides of lanthanides, and (2) heating of the obtained reaction products at a temperature of about 700 C in an inert gas atmosphere. The phase and chemical purities of the obtained materials were characterized by X-ray diffraction and mass spectrometry techniques. Single crystal growth tests were carried out by means of the Bridgman method. The results showed that the proposed method for manufacture of polycrystalline YLF doped with rare earth elements is appropriate in principle but some parameters of the preparation process are to be more strictly defined. (author). 9 refs, 4 figs, 1 tab

  7. Preparation of polycrystalline lithium-yttrium fluoride for subsequent mono crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Kowalczyk, E.; Radomski, J.; Diduszko, R.; Iwanejko, J. [Institute of Vacuum Technology, Warsaw (Poland); Kowalczyk, Z. [Warsaw Univ. (Poland); Grasza, K. [Polska Akademia Nauk, Warsaw (Poland). Inst. Fizyki

    1994-12-31

    High purity lithium-yttrium (YLF) doped with rare earth elements (Nd, Pr, Ho or Tm) was obtained in a two-stage synthesis consisting of (1) reaction of ammonium fluoride with a mixture of lithium carbonate, yttrium oxide, and oxides of lanthanides, and (2) heating of the obtained reaction products at a temperature of about 700 C in an inert gas atmosphere. The phase and chemical purities of the obtained materials were characterized by X-ray diffraction and mass spectrometry techniques. Single crystal growth tests were carried out by means of the Bridgman method. The results showed that the proposed method for manufacture of polycrystalline YLF doped with rare earth elements is appropriate in principle but some parameters of the preparation process are to be more strictly defined. (author). 9 refs, 4 figs, 1 tab.

  8. Lanthanide complexation in aqueous solutions

    International Nuclear Information System (INIS)

    Choppin, G.R.

    1984-01-01

    The lanthanide elements form an extended series of cations with the same charge, slightly varying radii and useful magnetic and spectroscopic properties. Their use in technology is growing rapidly as their properties are more fully explored. The lanthanides also offer scientists valuable and often unique probes for investigating a variety of chemical and physical phenomena. This review has attempted to call attention to these latter uses without trying to provide a thorough discussion of all the relevant literature. Hopefully, awareness of the more interesting facets of present studies of lanthanide complexes in aqueous solution will spur even more advances in the use of these elements. (Auth.)

  9. Characterization and excitation behaviour studies of radionuclide (scandium) in glass matrix

    International Nuclear Information System (INIS)

    Rehana, Ishrat; Shahid, K.A.; Husain, S.; Muhammad, Din

    1999-01-01

    Directional movements of bed load in marine sediments are studied using a radioactive tracer, scandium, similar to the natural sediment in the area. Scandium glass prepared for this purpose was analyzed by atomic emission spectrography for quality assurance purposes. A buffer composed of graphite with 5% germanium oxide was used for accurate and reproducible analyses. The role of this buffer in the excitation behavior of scandium and variations in spectral line intensity with respect to various influencing parameters are reported. Volatilization of scandium was observed using the moving plate technique, with a dc-arc as the excitation source

  10. Lanthanide Cofactors for Triphosphorylation Ribozymes

    Science.gov (United States)

    Sweeney, K. J.; Müller, U. F.

    2017-07-01

    RNA world organisms could have used trimetaphosphate as energy source for thermodynamically unfavorable RNA polymerization. Using in vitro selection we show here that Lanthanides can serve as cofactors for ribozyme-catalyzed RNA triphosphorylation.

  11. Scandium - problem of ultra-trace-element essentiality

    International Nuclear Information System (INIS)

    Kist, A.A.; Zkuk, L.I.; Danilova, E.A.; Makhmudov, E.A.

    2006-01-01

    Full text: Role of constitutional and essential elements in Life is known quite well. It is also well known that all chemical elements present in the living matter. Nevertheless essentiality of at least 55 chemical elements (more than a half of number of natural elements) is still not accepted. In many cases these elements presumably play important role in the Life. On the other hand their essentiality is still under doubt. One of the 'strange' elements in this connection is scandium. Scandium is an element which is very 'simple' for instrumental neutron activation analysis (INAA). For many years in our laboratory were carried out studies on animals and human tissues and fluids elemental composition using INAA in which data for scandium were obtained as 'redundant' information. Essentiality of scandium was newer proven using accepted criteria of elements. Nevertheless in our studies were found various regularities, statistically significant inter-elemental correlations and correlations between elements in tissues and fluids versus clinic and biochemical data. There are some examples. There were found correlations of scandium hair concentration and blood glucose (r=0.68±0.13), body mass index (r=0.86±0.07), leukocyte with phagocytic activity migration inhibition test (r=0.68±0.18), size of cavity of the left heart auricle (r=-0.65±0.16), final systolic bulk (r=0.80±0.12), stroke output of heart (r=-0.79±0.12), final diastolic bulk (0.88±0.0080) etc. In addition using gel filtration in rat liver cytosol was found peak of scandium in elution curve. Examples and correlations given in the paper say in favor that scandium may play quite important role in biological processes and that the biological role of scandium should be studied more intensive. The most important criterion is an appearance of the organism dysfunction in case of removal of the studied elements from the diet (intake) which in all other sides remains completely valuable and disappearance of all

  12. Complexing of scandium with eriochromecyanine R and cetyltrimethylammonium

    International Nuclear Information System (INIS)

    Tikhonov, V.N.; Samarkina, T.V.

    1978-01-01

    Complexing of scandium with eriochromecyanine R (ECC) in the presence of cetyltrimethylammonium (CTA) is studied. At optimum value of pH 6.2 a three-component complex of blue colour is forming with the Sc:ECC:CTA = 1:3:5 relation of compounds. Lambdasub(max) for the complex varies from 585 to 615 nm, molarabsorption coefficient is equal to (1.48+-0.02)x10 5 . A method of photometric determination of Sc with ECC and CTA is suggested. Even considerable quantities of Mg, Ca, Sr, Zn, Cd, La, Mn, Ni do not affect the Sc determination, whereas Cu, Be, Al, Ga, Fe(3) and Pd(2) affect it to a great degree even in relation of 1:1. Camouflaging substances such as fluorides, citrates, tartrates and EDTA prevent from scandium complexing, that is why they should not be used to increase the determination selectivity

  13. Lanthanide/Actinide Opacities

    Science.gov (United States)

    Hungerford, Aimee; Fontes, Christopher J.

    2018-06-01

    Gravitational wave observations benefit from accompanying electromagnetic signals in order to accurately determine the sky positions of the sources. The ejecta of neutron star mergers are expected to produce such electromagnetic transients, called macronovae (e.g. the recent and unprecedented observation of GW170817). Characteristics of the ejecta include large velocity gradients and the presence of heavy r-process elements, which pose significant challenges to the accurate calculation of radiative opacities and radiation transport. Opacities include a dense forest of bound-bound features arising from near-neutral lanthanide and actinide elements. Here we present an overview of current theoretical opacity determinations that are used by neutron star merger light curve modelers. We will touch on atomic physics and plasma modeling codes that are used to generate these opacities, as well as the limited body of laboratory experiments that may serve as points of validation for these complex atomic physics calculations.

  14. Incommensurate composite crystal structure of scandium-II

    International Nuclear Information System (INIS)

    Fujihisa, Hiroshi; Gotoh, Yoshito; Yamawaki, Hiroshi; Sakashita, Mami; Takeya, Satoshi; Honda, Kazumasa; Akahama, Yuichi; Kawamura, Haruki

    2005-01-01

    The long-unknown crystal structure of the high pressure phase scandium-II was solved by powder x-ray diffraction and was found to have tetragonal host channels along the c axis and guest chains that are incommensurate with the host, as well as the high pressure phases of Ba, Sr, Bi, and Sb. The pressure dependences of the lattice constants, the incommensurability, the atomic distances, and the atomic volume were investigated

  15. Tetragonal ternary borides: superconductivity, ferromagnetism and the role of scandium

    International Nuclear Information System (INIS)

    Matthias, B.T.; Patel, C.K.N.; Barz, H.; Corenzwit, E.; Vandenberg, J.M.

    1978-01-01

    The authors report and discuss two discoveries made while studying the condensation phenomena of ternary rhodium borides, MRh 4 B 4 . M is generally a trivalent transition metal, usually a rare earth element RE. An exception is scandium which by itself does not form an isomorphous boride, but in combination with many other elements will do just that. A suprising correlation between ferromagnetic and superconducting transition temperatures has been found. (Auth.)

  16. Determination of scandium with salicylaldehyde and 2-aminobenzenearsonic acid

    International Nuclear Information System (INIS)

    Farias, P.A.M.; Hainberger, L.; Andrade, H.A.S.

    1984-01-01

    A new method for the spectrophotometric determination of scandium by means of a coloured complex formed with salicylaldehyde and 2-aminobenzenearsonic acid is described. Lambert-Beer's law is followed in the range of 0.2 - 2.0 μg/ml of the final solution. The maximum amounts of 39 ions that may be present without interfering in the method are listed. (Author) [pt

  17. The characteristics of aluminum-scandium alloys processed by ECAP

    International Nuclear Information System (INIS)

    Venkateswarlu, K.; Rajinikanth, V.; Ray, Ajoy Kumar; Xu Cheng; Langdon, Terence G.

    2010-01-01

    Aluminum-scandium alloys were prepared having different scandium additions of 0.2, 1.0 and 2.0 wt.% and these alloys were processed by equal-channel angular pressing (ECAP) at 473 K. The results show the grain refinement of the aluminum matrix and the morphology of the Al 3 Sc precipitates depends strongly on the scandium concentration. The tensile properties were evaluated after ECAP by pulling to failure at initial strain rates from 1.0 x 10 -3 to 1.0 x 10 -1 s -1 . The Al-1% Sc alloy exhibited the highest tensile strength of ∼250 MPa at a strain rate of 1.0 x 10 -1 s -1 . This alloy also exhibited a superior grain refinement of ∼0.4 μm after ECAP where this is attributed to a smaller initial grain size and an optimum volume fraction of dispersed Al 3 Sc precipitates having both micrometer and nanometer sizes.

  18. Use of lanthanide catalysts in air electrodes

    International Nuclear Information System (INIS)

    Souza Parente, L.T. de

    1982-01-01

    A review on the lanthanide catalysts suitable for the reduction catalysis of oxygen in air electrodes is presented. The kinds of lanthanide indicated to be used as catalysts of oxygen reduction are shown. (A.R.H.) [pt

  19. Calibration beads containing luminescent lanthanide ion complexes

    Science.gov (United States)

    The reliability of lanthanide luminescence measurements, by both flow cytometry and digital microscopy, will be enhanced by the availability of narrow-band emitting lanthanide calibration beads. These beads can also be used to characterize spectrographic instruments, including mi...

  20. Extraction chromatography of lanthanides, ch. 8

    International Nuclear Information System (INIS)

    Siekierski, S.; Fidelis, I.

    1975-01-01

    The extraction of lanthanides by chelate formation with acidic organophosphorous extractants, by solvation of salts, and in the form of ion pairs is reviewed. The double-double effect and its significance for the lanthanide as well as the actinide separation is discussed. A short survey of the existing data on the enthalpies of lanthanide extraction and on the influence of temperature on their separation factor is given. The resolution ability of columns used for the separation of lanthanides is briefly surveyed

  1. Coprecipitation of yttrium and aluminium hydroxide for preparation of yttrium aluminium garnet

    NARCIS (Netherlands)

    Vrolijk, J.W.G.A.; Willems, J.W.M.M.; Metselaar, R.

    1990-01-01

    Coprecipitation of yttrium and aluminium hydroxide for the preparation of pure yttrium aluminium garnet (YAG) powder with small grain size is the subject of this study. Starting materials are sulphates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3Al5O12), the pH during flocculation

  2. Adsorption and desorption of hydrolyzed metal ions. 3. Scandium and chromium

    International Nuclear Information System (INIS)

    Gray, B.; Matijevic, E.; Clarkson Univ., Potsdam, NY

    1987-01-01

    Adsorption of scandium(III) and chromium(III) species on a PVC latex was measured using radioactive isotopes; the uptake increased with increasing pH. The data were interpreted by combining aspects of the models of James and Healy and also of Anderson and Bockris. The experimental and calculated results agree quite well for scandium, but not for chromium. The deviation in the latter case is believed to be due to polymerization of the hydrolyzed chromium cations and to the interaction of chromium with the anionic surface groups of the latex. Neither of these interactions occur with scandium. Hydrolyzed scandium species adsorbed on the latex were removed by acidifying the dispersion, while chromium complexes were not, substantiating the proposed difference in the chemical nature of chromium and scandium species at the solid/solution interface. 32 refs.; 8 figs.; 8 tabs

  3. A new model for prediction of dispersoid precipitation in aluminium alloys containing zirconium and scandium

    International Nuclear Information System (INIS)

    Robson, J.D.

    2004-01-01

    A model has been developed to predict precipitation of ternary Al 3 (Sc, Zr) dispersoids in aluminium alloys containing zirconium and scandium. The model is based on the classical numerical method of Kampmann and Wagner, extended to predict precipitation of a ternary phase. The model has been applied to the precipitation of dispersoids in scandium containing AA7050. The dispersoid precipitation kinetics and number density are predicted to be sensitive to the scandium concentration, whilst the dispersoid radius is not. The dispersoids are predicted to enrich in zirconium during precipitation. Coarsening has been investigated in detail and it has been predicted that a steady-state size distribution is only reached once coarsening is well advanced. The addition of scandium is predicted to eliminate the dispersoid free zones observed in scandium free 7050, greatly increasing recrystallization resistance

  4. Separation of lanthanides through hydroxyapatite

    International Nuclear Information System (INIS)

    Garcia M, F.G.

    2006-01-01

    With the objective of obtaining from an independent way to each one of the lanthanides 151 Pm, 161 Tb, 166 Ho and 177 Lu free of carrier and with high specific activities starting from the indirect irradiation via, it intends in this work to determine the viability of separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu, by means of ion exchange column chromatography, using hydroxyapatite (HAp) and fluorite like absorbent material in complexing media. It is important to mention that have registered separation studies among lanthanides of the heavy group with those of the slight group, using the same mass and, in comparison with this work, quantities different from the father were used and of the son, also, that the separation studies were carried out among neighboring lanthanides. In this investigation, it was determined the effect that its have the complexing media: KSCN, sodium tartrate, sodium citrate, EDTA and aluminon, their pH and concentration, in the adsorption of the lanthanides in both minerals, in order to determine the chromatographic conditions for separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu. The work consists of five chapters, in the first one they are presented a theoretical introduction of the characteristics more important of the lanthanides, the hydroxyapatite and the fluorite; in the second, it is deepened in the ion exchange, as well as the two techniques (XRD and High Vacuum Electron Microscopy) to make the characterization of LnCI 3 (Ln = Nd, Gd, Dy or Yb) synthesized. The third chapter, it describes the methodology continued in our experimental work; in the room, its are presented the obtained results of the static and dynamic method to determine the viability of separation of neighboring lanthanides; and finally, the five chapter shows the conclusions. In this study, it is concludes that the separation among neighboring lanthanides cannot be carried out in the minerals and used media; because practically these lanthanides

  5. Kinetics and mechanism of hydrolysis of scandium sulfate

    International Nuclear Information System (INIS)

    Koshchej, E.V.; Stryapkov, A.V.; Podosenov, D.E.; Makarov, G.V.; Razdobreev, D.A.

    1998-01-01

    The Sc 2 (SO 4 ) 3 -H 2 SO 4 -H 2 O system is studied through the methods of pH-potentiometry, conductometry and turbidimetry at 298 and 318 K and ion force 0.01, 0.1 and 1.0. The hydrolysis mechanism including the processes in the system homogenous and heterogeneous constituents. The hydrolysis rates of scandium salts and their dependences on OH-ions concentration, solution ions force and temperature are found; the constants of the processes rate with participation of OH - and SO 4 2- ions and constants of the solid phase formation rate are calculated [ru

  6. Vibrational spectra of double oxides of calcium and scandium

    International Nuclear Information System (INIS)

    Porotnikov, N.V.; Kondratov, O.I.; Petrov, K.I.; Olikov, I.I.

    1981-01-01

    The vibrational spectra of calcium and scandium double oxides 40 CaSc 2 O 4 and 44 CaSc 2 O 4 in the range of 30-1000 cm -1 are studied. In the approximation of the polymer chains of the method of valent-force field the calculation of the theoretical vibrational spectrum of isotope-substituted compounds is made, the attribution of the experimental spectra is suggested, the frequency branches of the vibrations of periodic chains are built, the force field of crystals is evaluated [ru

  7. Texture and deformation mechanism of yttrium

    International Nuclear Information System (INIS)

    Adamesku, R.A.; Grebenkin, S.V.; Stepanenko, A.V.

    1992-01-01

    X-ray pole figure analysis was applied to study texture and deformation mechanism in pure and commercial polycrystalline yttrium on cold working. It was found that in cast yttrium the texture manifected itself weakly enough both for pure and commercial metal. Analysis of the data obtained made it possible to assert that cold deformation of pure yttrium in the initial stage occurred mainly by slip the role of which decreased at strains higher than 36%. The texture of heavily deformed commercial yttrium contained two components, these were an 'ideal' basic orientation and an axial one with the angle of inclination about 20 deg. Twinning mechanism was revealed to be also possible in commercial yttrium

  8. Scandium effect on mechanical properties of Al-6.5 % Mg alloy

    International Nuclear Information System (INIS)

    Drits, M.E.; Toropova, L.S.; Bykov, Yu.G.

    1982-01-01

    Quantitative evaluation of influence of small scandium additions (up to 0.5 wt%) on properties of Al-6.5% Mg binary alloy are carried out depending on test temperature in the range of -196 to 310 deg C. Alloys were tested on ''Instron'' machine at 1.3x10 - 3 s - 1 strain rate. Scandium additions are shown to increase plasticity at -196 deg C. Yield strength also increases with introduction of 0.2% Sc if deformation temperature does not exceed 250 deg C. The growth of ultimate strength is less significant. Elevated strength properties of alloys with scandium additions can be explained by a fine-grained structure

  9. Effect of scandium additions on microstructure and mechanical properties of Al-Zn-Mg alloy welds

    International Nuclear Information System (INIS)

    Dev, Selvi; Stuart, A. Archibald; Kumaar, R.C. Ravi Dev; Murty, B.S.; Rao, K. Prasad

    2007-01-01

    The microstructure and mechanical properties of fusion zones of medium strength Al-Zn-Mg alloy (RDE-40) welds obtained by using different fillers containing various amount of scandium was investigated. It was observed that addition of scandium led to very significant grain refinement in the fusion zone especially for scandium levels greater than the eutectic composition (0.55 wt%). The grain refinement led to the reduction in solidification cracking and improved the tensile properties of fusion zone compared to the ones obtained by the commercial AA5556 filler

  10. Biological toxicity of lanthanide elements on algae.

    Science.gov (United States)

    Tai, Peidong; Zhao, Qing; Su, Dan; Li, Peijun; Stagnitti, Frank

    2010-08-01

    The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04+/-0.61 micromol L(-1)) resulted in 50% reduction in growth of algae compared to the controls (0 micromol L(-1)) after 96 h (96 h-EC50). The biological toxicity of 13 lanthanides on marine monocellular algae was unrelated with the abundance of different lanthanide elements in nature, and the "Harkins rule" was not appropriate for the lanthanides. A mixed solution that contained equivalent concentrations of each lanthanide element had the same inhibition effect on algae cells as each individual lanthanide element at the same total concentration. This phenomenon is unique compared to the groups of other elements in the periodic table. Hence, we speculate that the monocellular organisms might not be able to sufficiently differentiate between the almost chemically identical lanthanide elements. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  11. Adsorption behaviour of scandium, yttrium, cerium and uranium from xylenol orange solutions onto anion-exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Chao, H E; Suzuki, N [Tohoku Univ., Sendai (Japan). Faculty of Science

    1981-04-01

    The effects of concentration, pH and anions on the adsorption behaviour of xylenol orange (XO) on the strong anion exchangers, Amberlite IRA-400 and Hitachi 2632 are described. The adsorption behaviour of the XO complexes of Ce(III), Y(III), Sc(III) and U(VI) on the Amberlite IRA-400 resin as a function of XO concentration and pH is reported. A continuous-flow radiometric detector is used to investigate the separations of the Ce(III)-Sc(III), Y(III)-Sc(III), and Ce(III)-Y(III) pairs on the XO-form Hitachi 2632 resin column by pH control. Satisfactory separations of the Ce(III)-Sc(III) and Y(III)-Sc(III) pairs are achieved.

  12. Interaction of intermetallic compounds formed by rare earths, scandium, yttrium and 3d-transition metals, with gaseous ammonia

    International Nuclear Information System (INIS)

    Shilkin, S.P.; Volkova, L.S.

    1992-01-01

    Interaction of the RT n intermetallic compounds, where R Sc, Y, rare earths, T = Fe, Co, Ni; n = 2,3,5, with gaseous ammonia under pressure of 1MPa and at temperatures of 293, 723 and 798 K is studied. It is established on the basis of roentgenographic studied, chemical analysis data, X-ray photoelectron spectroscopy and specific surface measurements that metallic matrixes of intermetallides decompose into nitrides and transition metal phases at temperatures of 723 and 798 K under effect of ammonia and independent of structural types of the source materials; partial or complete decomposition of intermetallides through ammonia with formation of transition metal mixture, binary hydrides and nitrides of the most electropositive metal the above systems occurs at the temperature of 293 K depending on the heat of the source compounds and their tendency to decomposition under ammonia effect

  13. Hydrothermal synthesis, crystal structures and photoluminescence properties of mixed europium–yttrium organic frameworks

    International Nuclear Information System (INIS)

    Han Yinfeng; Fu Lianshe; Mafra, Luís; Shi, Fa-Nian

    2012-01-01

    Three mixed europium–yttrium organic frameworks: Eu 2−x Y x (Mel)(H 2 O) 6 (Mel=mellitic acid or benzene-1,2,3,4,5,6-hexacarboxylic acid, x=0.38 1, 0.74 2, and 0.86 3) have been synthesized and characterized. All the compounds contain a 3-D net with (4, 8)-flu topology. The study indicates that the photoluminescence properties are effectively affected by the different ratios of europium and yttrium ions, the quantum efficiency is increased and the Eu 3+ lifetime becomes longer in these MOFs than those of the Eu analog. - Graphical abstract: Three mixed europium and yttrium organic frameworks: Eu 2−x Y x (Mel)(H 2 O) 6 (Mel=mellitic acid) have been synthesized and characterized. All the compounds contain a 3-D net with (4, 8)-flu topology. The study indicates that the photoluminescence properties are effectively affected by the different ratios of europium and yttrium ions, the quantum efficiency is increased and the Eu 3+ lifetime becomes longer in these MOFs than those of the Eu analog. Highlights: ► Three (4, 8)-flu topological mixed Eu and Y MOFs were synthesized under mild conditions. ► Metal ratios were refined by the single crystal data consistent with the EDS analysis. ► Mixed Eu and Y MOFs show longer lifetime and higher quantum efficiency than the Eu analog. ► Adding inert lanthanide into luminescent MOFs enlarges the field of luminescent MOFs.

  14. Reaction of yttrium polonides with carbon dioxide

    International Nuclear Information System (INIS)

    Abakumov, A.S.; Khokhlov, A.D.; Reznikova, N.F.

    1986-01-01

    It has been proved that heating of yttrium and tantalum in carbon dioxide to 500 and 800 0 C alters the gas phase composition, causing formation of carbon monoxide and reduction of oxygen content. A study of the thermal stability of yttrium polonides in carbon dioxide showed that yttrium sesqui- and monopolonides decompose at 400-430 0 C. The temperature dependence of the vapor pressure of polonium obtained upon decomposition of the referred polonides has been determined in a carbon dioxide environment radiotensometrically. The enthalpy of the process calculated from this dependence is close to the enthalpy of vaporization of elemental polonium in vacuo. The mechanism of the reactions has been suggested

  15. Complexonometric photometric titration of scandium in the presence of xylenol orange

    International Nuclear Information System (INIS)

    Kornev, V.I.

    1977-01-01

    Possibility has been studied of using xylenol orange (XO) for chelatometric determination of scandium by means of various chelates with the aid of photometric techniques. It has been established that the chelates applicable for the purpose are ethylenediamineteraacetic acid (EDTA), diethylenediaminetetraacetic acid (DEDTA), diethylenetriaminepentaacetic acid (DETPA), upon introducing of which into a solution containing a complex of scandium with XO (maximum light adsorption at 550 nm) the optical density gradually diminishes. Weakening of the light absorption is, evidently, associated with the destruction of the scandium complex with XO and formation of a colourless chelate acetate with one of the chelates. Chelatometric determination of scandium, using EDTA, DEDTA and DEPTA solutions with XO should be carried out in an acidic medium at pH=2.5-3.0. In this range of pH values interferences caused by the appearance of the Sc-XO complex in the solution are insignificant

  16. Knight shift in scandium and its alloys with hafnium and titanium

    International Nuclear Information System (INIS)

    Chachkhiani, Z.B.; Chechernikov, V.I.; Martynova, L.F.; Nidel'ko, V.I.; Chachkhiani, L.G.; Georgadze, G.S.

    1981-01-01

    Results of the investigation of NMR on 45 Sc nuclei and magnetic susceptibility of scandium and its solid solutions with titanium and hafnium are presented. It is shown that the existing hybridization of S and d zones in pure scandium and its alloys with titanium and hafnium affects the Knight shift reducing the value of the contact contribution. The temperature behaviour of the Knight shift from the temperature dependence and spin susceptibility of collectivized d electrons [ru

  17. Use of scandium ionic associates with salicylic- or 2-phenylquinoline-4-carboxylic acid and rhodamine C

    Energy Technology Data Exchange (ETDEWEB)

    Kononenko, L.I.; Bel' tyukova, S V; Drobyazko, V N; Poluehktov, N S [AN Ukrainskoj SSR, Kiev. Inst. Obshchej i Neorganicheskoj Khimii; AN Ukrainskoj SSR, Odessa. Inst. Obshchej i Neorganicheskoj Khimii)

    1975-09-01

    With salicylic or 2-phenylquinoline-4-carboxylic acid and rhodamine C scandium forms ion associations whose benzene solutions are capable of luminescence. Optimum conditions for the formation of complexes and the composition of the complex with the ratio of Sc:acid:rhodamine C = 1:2:1 are established. A possibility of luminescence determination of scandium in the presence of rare earths is shown.

  18. Analogs of N-cynnamoylphenylhydroxylamine as reagents for amperometric determination of scandium

    International Nuclear Information System (INIS)

    Shvedene, N.V.; Gallaj, Z.A.; Sheina, N.M.; Zujkova, N.V.

    1978-01-01

    To decrease the detection limit of scandium and increase selectivity of amperometric determination, oxidation of 2-furylacryloyl-N-p-chlorophenylhydroxylamine (FACPhHA) and 3-styrylacryloyl-N-phenylhydroxylamine (SAPhHA) on a graphite electrode has been studied by volt-amperometry. The possibility has been established of using the oxidation current of the reagent for plotting the titration curves. The solubility of scandium complexes with FACPhHA and SAPhHA under conditions of titration against the background with pH 6.0 has been determined and equals (2.1+-0.3)x10 -6 and (5.3+-0.3)x10 -7 , respectively. The methods have been developed of amperometric determination of scandium with the use of the considered reagents against backgrounds with pH 5.5-6.5. The use of SAPhHA has decreased the limit of scandium detection down to 0.1 mgk/ml. Besides, the amperometric method makes it possible to titrate in turbid and coloured media what is an advantage of this method. The developed method is used for determination of scandium in scandium silicide

  19. Effect of composition on the superplasticity of aluminium scandium alloys

    International Nuclear Information System (INIS)

    Bradley, E.L. III; Morris, J.W. Jr.

    1992-01-01

    Several aluminum alloys have been shown to exhibit superplasticty in the as-rolled condition. Previous work has shown that aluminum-scandium alloys also exhibit this behavior, but only with the addition of ternary alloying elements such as lithium and magnesium. These additions raised the strain-rate sensitivity of these alloys to 0.4-0.5 for selected strain rates at temperatures above 400 degrees C. A systematic study was undertaken of five Al-Sc alloys with varying lithium and magnesium concentrations in order to fully characterize the high temperature deformation mechanism. Specimens were deformed at a constant strain rate to predetermined true strains for textural and microstructural characterization. In this paper work is presented that will elucidate the effect of these different ternary additives on the superplastic deformation mechanism in these alloys

  20. Application of scandium oxide in an electron emission material

    International Nuclear Information System (INIS)

    Suqiu, Y.; Zhizheng, Z.; Yongde, W.

    1985-01-01

    Modern microwave devices impose a number of harsh requirements on the cathodes. For instance, they require cathodes having low working temperature, high emissive current density, slow evaporation rate of the emissive-active material, long lifetime, quick heating and so on. The commercial B-cathode is no longer able to meet these requirements completely. A scandate cathode may be a promising one for use in these devices. Adding rare-earth elements in the electron emission material has been reported in many papers. Based on a B-cathode we add a little amount of scandium oxide (about 3%) into emission material to manufacture a scandate cathode. The emission property of such a cathode has been improved greatly. If the composition is controlled correctly, the emission level of such a cathode may be five times more as high as the B-cathode

  1. Order-disorder phenomenon in lead scandium tantalate

    International Nuclear Information System (INIS)

    Wang, H.C.; Schulze, W.A.

    1990-01-01

    Lead scandium tatalate (PST) is a ferroelectric relaxor with the perovskite structure of A(B'B double-prime)O 3 . By suitable heat treatment, the B-site cations can be brought from a structurally disordered state into various degree of ordering. The degree of ordering is strongly affected by the amount of vacancies present in the materials. To suppress PbO loss during the sintering or annealing process, a PbO-rich atmosphere is supplied by materials having high PbO vapor pressure, such as PbZrO 3 . For PST ceramics with nearly zero weight loss, very long annealing times and higher annealing temperatures are required for ordering. The higher PbO-loss materials are found to be easily ordered. The introduction of a reducing atmosphere during annealing enhances the ordering process. The ordering process is characterized quantitatively by X-ray diffraction and qualitatively by Raman spectroscopy

  2. Electronic structure of lanthanide scandates

    Science.gov (United States)

    Mizzi, Christopher A.; Koirala, Pratik; Marks, Laurence D.

    2018-02-01

    X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and density functional theory calculations were used to study the electronic structure of three lanthanide scandates: GdSc O3,TbSc O3 , and DySc O3 . X-ray photoelectron spectra simulated from first-principles calculations using a combination of on-site hybrid and GGA +U methods were found to be in good agreement with experimental x-ray photoelectron spectra. The hybrid method was used to model the ground state electronic structure and the GGA +U method accounted for the shift of valence state energies due to photoelectron emission via a Slater-Janak transition state approach. From these results, the lanthanide scandate valence bands were determined to be composed of Ln 4 f ,O 2 p , and Sc 3 d states, in agreement with previous work. However, contrary to previous work the minority Ln 4 f states were found to be located closer to, and in some cases at, the valence band maximum. This suggests that minority Ln 4 f electrons may play a larger role in lanthanide scandate properties than previously thought.

  3. Yttrium doped BSCF membranes for oxygen separation

    DEFF Research Database (Denmark)

    Haworth, P.; Smart, S.; Glasscock, Julie

    2011-01-01

    This work investigates the partial substitution of yttrium in place of iron in BSCF to form Ba0.5Sr0.5Co0.8Fe0.2−xYxO3−δ, where x varied between 0 and 0.2. X-ray diffraction patterns showed the formation of a perovskite cubic phase structure up to x = 0.15, whilst the full substitution of yttrium...

  4. Crystallization of Yttrium and Samarium Aluminosilicate Glasses

    OpenAIRE

    Lago, Diana Carolina; Prado, Miguel Oscar

    2016-01-01

    Aluminosilicate glasses containing samarium and yttrium (SmAS and YAS glasses) exhibit high glass transition temperatures, corrosion resistance, and glass stability on heating which make them useful for technological applications. Yttrium aluminosilicate glass microspheres are currently being used for internal selective radiotherapy of liver cancer. During the preparation process, crystallization needs to be totally or partially avoided depending on the final application. Thus knowing the cry...

  5. Complexation of some trivalent lanthanides, scandium(III) and thorium(IV) by benzylidenepyruvates in aqueous solution

    International Nuclear Information System (INIS)

    Marques, R.N.; Moraes, M. de; Ionashiro, M.

    1997-01-01

    The protonation constants of 4-methylbenzylidenepyruvate (4Me-BP) and 4-isopropylbenzylidenepyruvate (4IP-BP) as well as the stability constants of their binary 1:1 complexes with Cu(II), La(III), Pr(III), Sm(III), Eu(III), Yb(III), Sc(III) and Th(IV) have been determined spectrophotometrically in aqueous solution at 25 C and ionic strength 0.500 M, maintained with sodium perchlorate. For all metal ions considered, the stability changes move in the same direction as the pK a of the ligands. Linear free energy relationships, as applied to oxygen donor substances, suggest the -COCOO - moiety as the metal binding site of the ligands. The results are discussed mainly taking into account that benzylidenepyruvates, besides the α-keto canonical form, may display other forms in aqueous solution with changing pH and the possible occurrence of extra intra-ligand charge polarization, induced by metal ions. (orig.)

  6. Photometric micro-determination of scandium and lanthanides by direct and successive titration using semi-xylenol orange

    International Nuclear Information System (INIS)

    Hafez, M.A.E.H.; Eman, M.E.S.M.

    1986-01-01

    The precision and accuracy attainable in direct titrations of the Sc 3+ , La 3+ or Er 3+ ion with a 0.001 M solution of the disodium salt of EDTA using semi-xylenol orange (SXO) as a metallochromic indicator were studied. Accurate results can be achieved by successive titration. The Sc 3+ ion is titrated at pH 2.4, the pH is adjusted to 5.6-5.9 by adding hexamethylenetetramine buffer solution and the La 3+ ion (or Er 3+ ion) is then titrated. A comparison of SXO and xylenol orange indicators for the successive titration of the Sc 3+ ion and lanthanum or erbium was carried out. (author)

  7. Lanthanides, thorium, iodine in terrestrail invertebrates

    International Nuclear Information System (INIS)

    Zhulidov, A.V.; Pokarzhevskij, A.D.; Katargin, N.V.; AN SSSR, Moscow

    1991-01-01

    It is shown that among examined terrestrial invertebrates the highest levels on lanthanide and thorium concentration are typical for animals, feeding on plant tissues - earthworms, molluscs, diploid. It is shown that there are no reasons to hope, that regularities of migration of transuranium elements and lanthanides in tropic chains are identical

  8. A sensitive fluorescent sensor of lanthanide ions

    CERN Document Server

    Bekiari, V; Lianos, P

    2003-01-01

    A fluorescent probe bearing a diazostilbene chromophore and a benzo-15-crown-5 ether moiety is a very efficient sensor of lanthanide ions. The ligand emits strong fluorescence only in the presence of specific ions, namely lanthanide ions, while the emission wavelength is associated with a particular ion providing high sensitivity and resolution.

  9. Concentration and Separation of Scandium from Ni Laterite Ore Processing Streams

    Directory of Open Access Journals (Sweden)

    Şerif Kaya

    2017-12-01

    Full Text Available The presence of a considerable amount of scandium in lateritic nickel-cobalt ores necessitates the investigation of possible processing alternatives to recover scandium as a byproduct during nickel and cobalt production. Therefore, in this study, rather than interfering with the main nickel-cobalt production circuit, the precipitation-separation behavior of scandium during a pH-controlled precipitation process from a synthetically prepared solution was investigated to adopt the Sc recovery circuit into an already existing hydrometallurgical nickel-cobalt hydroxide processing plant. The composition of the synthetic solution was determined according to the hydrometallurgical nickel laterite ore processing streams obtained from a HPAL (high-pressure sulphuric acid leaching process. In order to selectively precipitate and concentrate scandium with minimum nickel and cobalt co-precipitation, the pH of the solution was adjusted by CaCO3, MgO, Na2CO3, and NaOH. It was found that precipitation with MgO or Na2CO3 is more advantageous to obtain a precipitate containing higher amounts of scandium with minimum mass when compared to the CaCO3 route, which makes further processing more viable. As a result of this study, it is proposed that by a simple pH-controlled precipitation process, scandium can be separated from the nickel and cobalt containing process solutions as a byproduct without affecting the conventional nickel-cobalt hydroxide production. By further processing this scandium-enriched residue by means of leaching, SX (solvent extraction, and precipitation, an intermediate (NH42NaScF6 product can be obtained.

  10. Analysis of separation quality of scandium-46 and titanium using silica gel column

    International Nuclear Information System (INIS)

    Muhamad Basit Febrian; Yanuar Setiadi; Duyeh Setiawan; Titin Sri Mulyati; Nana Suherman

    2015-01-01

    In this study, quality test of scandium and titanium mixture separation system using a silica gel column has been conducted. This system will be used in the separation of medical radioisotopes of 47 Sc from TiO 2 enriched targets. 20 mg of TiO 2 and 5 mg of Sc 2 O 3 dissolved using 0.5 mL of 50% HF solvent with gentle heating at 60°C - 80°C for 1 hour then 4.5 mL H 2 O was added. Sc and Ti mixture is separated by passing it through a column of silica gel. In the determination of scandium released from silica gel, Sc-46 radiotracer was used. Only 51.60 ± 4.5% of 5 mg of scandium could be retained in the silica gel column. From 51.60% of absorbed scandium in the column, 98.29 ± 3.4% were eluted with 5 mL of H 2 O eluent. During elution of scandium from silica gel column, 2.81 grams of 20 mg of titanium came apart as breakthrough. In determination of recovery of titanium from silica gel, 51.76 ± 5.5% of the 20 mg Ti can be recovered from silica gel column using 5M HCl eluent, whereas remaining Ti were eluted using 40 ml of HCl 5M. Based on those result, it can be concluded that there are still titanium portion in scandium after the separation using a silica gel column. Further purification step using fresh silica gel column, can separate escaped titanium from scandium. (author)

  11. Addition compounds of lanthanide and yttrium-perchlorates and nitrates with N,N-Dimethylbenzamide (DMBA)

    International Nuclear Information System (INIS)

    Giesbrecht, E.; Tfouni, E.; Sao Paulo Univ.

    1980-01-01

    The synthesis and physical properties of the compounds Ln(ClO 4 ) 3 .6 DMBA and Ln.(NO 3 ) 3 .3DMBA (Ln=La to Lu, except Pm, and including Y), (DMBA=N,N-dimethylbenzamide) are reported. They were characterized by elemental analysis, melting ranges, infrared spectra, electrolytic conductance measurements and X-ray diffraction powder patterns. (Author) [pt

  12. Lanthanide-doped luminescent ionogels

    OpenAIRE

    Lunstroot, Kyra; Driesen, Kris; Nockemann, Peter; Van Hecke, Kristof; Van Meervelt, Luc; Görller-Walrand, Christiane; Binnemans, Koen; Bellayer, Séverine; Viau, Lydie; Le Bideau, Jean; Vioux, André

    2009-01-01

    Ionogels are solid oxide host networks confining at a meso-scale ionic liquids, and retaining their liquid nature. Ionogels were obtained by dissolving anthanide(III) complexes in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C6mim][Tf2N], followed by confinement of the lanthanide-doped ionic liquid mixtures in the pores of a nano-porous silica network. [C6mim][Ln(tta)4], where tta is 2-thenoyltrifluoroacetonate and Ln = Nd, Sm, Eu, Ho, Er, Yb, and [choli...

  13. DFTB{sup +} and lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Hourahine, B [Department of Physics, SUPA, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG (United Kingdom); Aradi, B; Frauenheim, T, E-mail: benjamin.hourahine@strath.ac.u [BCCMS, Universitaet Bremen, Am Fallturm 1, 28359 Bremen (Germany)

    2010-07-01

    DFTB{sup +} is a recent general purpose implementation of density-functional based tight binding. One of the early motivators to develop this code was to investigate lanthanide impurities in nitride semiconductors, leading to a series of successful studies into structure and electrical properties of these systems. Here we describe our general framework to treat the physical effects needed for these problematic impurities within a tight-binding formalism, additionally discussing forces and stresses in DFTB. We also present an approach to evaluate the general case of Slater-Koster transforms and all of their derivatives in Cartesian coordinates. These developments are illustrated by simulating isolated Gd impurities in GaN.

  14. Interaction of oxygen vacancies in yttrium germanates

    KAUST Repository

    Wang, Hao

    2012-01-01

    Forming a good Ge/dielectric interface is important to improve the electron mobility of a Ge metal oxide semiconductor field-effect transistor. A thin yttrium germanate capping layer can improve the properties of the Ge/GeO 2 system. We employ electronic structure calculations to investigate the effect of oxygen vacancies in yttrium-doped GeO 2 and the yttrium germanates Y 2Ge 2O 7 and Y 2GeO 5. The calculated densities of states indicate that dangling bonds from oxygen vacancies introduce in-gap states, but the system remains insulating. However, yttrium-doped GeO 2 becomes metallic under oxygen deficiency. Y-doped GeO 2, Y 2Ge 2O 7 and Y 2GeO 5 are calculated to be oxygen substoichiometric under low Fermi energy conditions. The use of yttrium germanates is proposed as a way to effectively passivate the Ge/dielectric interface. This journal is © 2012 the Owner Societies.

  15. Effects of iron on intermetallic compound formation in scandium modified Al–Si–Mg Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Patakham, Ussadawut [National Metal and Materials Technology Center, National Science and Technology Development Agency, 114 Thailand Science Park, Klong Nueng, Klong Luang, Pathumthani 12120 (Thailand); Limmaneevichitr, Chaowalit, E-mail: chaowalit.lim@mail.kmutt.ac.th [Production Engineering Department, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, 126 Pracha-Utid Rd., Bangmod, Tungkhru, Bangkok 10140 (Thailand)

    2014-12-15

    Highlights: • Iron reduces the modification effects of scandium in Al–Si–Mg alloys. • Morphologies of Sc-rich intermetallic phases vary with Fe and Sc contents and the cooling rates. • Sc neutralizes effects of Fe by changing Fe-rich intermetallic phases from platelets to more cubic. - Abstract: In general, iron has a strong tendency to dissolve in molten aluminum. Iron has very low solid solubility in aluminum–silicon casting alloys, so it will form intermetallic compounds that cause detrimental effects on mechanical properties. In this work, the effects of iron on intermetallic compound formations in scandium modified Al–Si–Mg alloys were studied. There were two levels of iron addition (0.2 and 0.4 wt.%) and two levels of scandium addition (0.2 and 0.4 wt.%). We found that the effects of scandium modification decreased with increasing iron addition. The morphologies of the complex intermetallic compounds were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD) techniques. It was found that scandium changes the morphology of Fe-rich intermetallic compounds from β-phase (plate-like) to α-phase, which reduces the harmful effects of β-phase.

  16. Kinetics of yttrium dissolution from waste ceramic dust

    OpenAIRE

    STOPIC SRECKO R.; FRIEDRIH BERND G.

    2016-01-01

    Yttrium is a silvery transition metal and has similar chemical properties to lanthanoids. Because of this similarity, yttrium belongs to rare earth elements. Ytttrium and yttrium oxide are mostly used in fluoroscent lamps, production of electrodes, in electronic filters, lasers, superconductors and as additives in various materials to improve their properties. Yttrium is mainly recovered from the minerals monazite [(Ce,La,Th,Nd,Y)PO4] and xenotime YPO4.The presence of radioactive elements suc...

  17. Study for the determination of samarium, europium,terbium, dysprosium and yttrium in gadolinium oxide matrix by means of atomic absorption spectrophotometry using a graphite furnace

    International Nuclear Information System (INIS)

    Caires, A.C.F.

    1985-01-01

    A study for determination of samarium, europium, terbium, dysprosium and yttrium in a gadolinium oxide matrix by atomic absorption spectrophotometry using a graphite furnace is presented. The best charrring and atomization conditions were estabilished for each element, the most convenient ressonance lines being selected as well. The study was carried out for the mentioned lanthanides both when pure and when in binary mixtures with gadolinium, besides those where all for them were together with gadolinium. The determination limits for pure lanthanides were found to be between 1.3 and 9.6 ng assuming a 20% relative standard deviation as acceptable. The detection limits were in the range 0.51 and 7.5 ng, assuming as positive any answer higher than twofold the standard deviation. (author) [pt

  18. Hydrogen storage in thin film magnesium-scandium alloys

    International Nuclear Information System (INIS)

    Niessen, R.A. H.; Notten, P.H. L.

    2005-01-01

    Thorough electrochemical materials research has been performed on thin films of novel magnesium-scandium hydrogen storage alloys. It was found that palladium-capped thin films of Mg x Sc (1-x) with different compositions (ranging from x=0.50 -0.90) show an increase in hydrogen storage capacity of more than 5-20% as compared to their bulk equivalents using even higher discharge rates. The maximum reversible hydrogen storage capacity at the optimal composition (Mg 80 Sc 20 ) amounts to 1795-bar mAh/g corresponding to a hydrogen content of 2.05 H/M or 6.7-bar wt.%, which is close to five times that of the commonly used hydride-forming materials in commercial NiMH batteries. Galvanostatic intermittent titration technique (GITT) measurements show that the equilibrium pressure during discharge is lower than that of bulk powders by one order of magnitude (10 -7 -bar mbar versus 10 -6 -bar mbar, respectively)

  19. The spectrum of four times ionized scandium, Sc V

    International Nuclear Information System (INIS)

    Smitt, R.; Ekberg, J.O.

    1985-01-01

    The spectrum of four times ionized scandium emitted from a sliding spark discharge has been observed using a 3 m normal incidence spectrograph and a 5 m grazing incidence spectrograph. About 450 lines in the wavelength region 160 A to 220 A have been identified as combinations between 46 odd levels belonging to the 3s 2 3p 5 , 3s 2 3p 4 4p and 3s3p 5 3d configurations and 72 even levels of the 3s3p 6 , 3s 2 3p 4 3d, 4d, 4s and 5s configurations. Of the previous identifications we have confirmed 18 levels. The level structure of the observed configurations has been theoretically interpreted by including configuration interaction effects. The inclusion of 3s 2 3p 3 3d 2 in the calculations of the odd parity configurations is found to be important. Almost all levels of 3s3p 5 3d show a considerable mixing with levels of 3s 2 3p 3 3d 2 , in some cases by as much as 50%. The energy parameters determined from least-squares fits to the observed level values are compared with Hartree-Fock calculations. The ionization energy is estimated to be 739 500 +- 1000 cm -1 . (91.65 +- 0,12 eV). (orig.)

  20. Aluminum-Scandium: A Material for Semiconductor Packaging

    Science.gov (United States)

    Geissler, Ute; Thomas, Sven; Schneider-Ramelow, Martin; Mukhopadhyay, Biswajit; Lang, Klaus-Dieter

    2016-10-01

    A well-known aluminum-scandium (Al-Sc) alloy, already used in lightweight sports equipment, is about to be established for use in electronic packaging. One application for Al-Sc alloy is manufacture of bonding wires. The special feature of the alloy is its ability to harden by precipitation. The new bonding wires with electrical conductivity similar to pure Al wires can be processed on common wire bonders for aluminum wedge/wedge (w/w) bonding. The wires exhibit very fine-grained microstructure. Small Al3Sc particles are the main reason for its high strength and prevent recrystallization and grain growth at higher temperatures (>150°C). After the wire-bonding process, the interface is well closed. Reliability investigations by active power cycling demonstrated considerably improved lifetime compared with pure Al heavy wires. Furthermore, the Al-Sc alloy was sputter-deposited onto silicon wafer to test it as chip metallization in copper (Cu) ball/wedge bonding technology. After deposition, the layers exhibited fine-grained columnar structure and small coherent Al3Sc particles with dimensions of a few nanometers. These particles inhibit softening processes such as Al splashing in fine wire bonding processes and increase the thickness of remnant Al under the copper balls to 85% of the initial thickness.

  1. Thermomechanical treatment of welded joints of aluminum-lithium alloys modified by scandium

    Science.gov (United States)

    Malikov, A. G.

    2017-12-01

    At present, the aeronautical equipment manufacture involves up-to-date high-strength aluminum alloys of decreased density resulting from the lithium admixture. Various technologies of fusible welding of these alloys are being developed. The paper presents experimental investigations of the optimization of the laser welding of aluminum alloys with the scandium-modified welded joint after thermomechanical treatment. The effect of scandium on the micro- and macrostructure is studied along with strength characteristics of the welded joint. It is found that thermomechanical treatment allows us to obtain the strength of the welded joint 0.89 for the Al-Mg-Li system and 0.99 for the Al-Cu-Li system with the welded joint modified by scandium in comparison with the base alloy after treatment.

  2. The enthalpy of solid scandium in the temperature range 406 - 1812 K

    International Nuclear Information System (INIS)

    Lyapunov, K.M.; Baginskij, A.V.; Stankus, S.V.

    2001-01-01

    Enthalpy of pure scandium was measured on massive calorimeter in the range from 406 to 1812 K by mixing method. The enthalpy of face centered close cubic lattice - body centered cubic lattice transformation is equal to ΔH t 4068 J/mol. Obtained value within the limits of error is compatible with the results given earlier (4009 J/mol). The dependence of the middle specific heat of scandium C p (T) on the temperature was shown in correlation with the results of other works. The results of the conducted experiments reinforce the conclusion made earlier about an absence (or a little) in the decomposition of an anharmonic component of the oscillation specific heat of scandium C p a (T) members proportional to the first or the second degrees of temperature [ru

  3. Pressure-induced structural change from hexagonal to fcc metal lattice in scandium trihydride

    International Nuclear Information System (INIS)

    Ohmura, A.; Machida, A.; Watanuki, T.; Aoki, K.; Nakano, S.; Takemura, K.

    2007-01-01

    We synthesized scandium hydrides by hydrogenation of a scandium foil with hydrogen fluid under high pressure at ambient temperature. Scandium dihydride (ScH 2 ) and trihydride (ScH 3 ) were prepared near 4 and 5 GPa, respectively. The hydrogenation process and pressure-induced structural changes in ScH 3 were investigated by synchrotron radiation X-ray diffraction measurements up to 54.7 GPa. A structural transition from hexagonal to the fcc lattice began at 30 GPa and was completed at 46 GPa via an intermediate state similar to those reported for other hexagonal trihydrides. The intermediate state was not interpreted in terms of a coexisting state for the low-pressure hexagonal and the high-pressure fcc structures. The onset transition pressure of ScH 3 supported the previously proposed relation that the hexagonal-fcc transition pressure is inversely proportional to the ionic radius of the trihydride

  4. Features of solid solutions composition in magnesium with yttrium alloys

    International Nuclear Information System (INIS)

    Drits, M.E.; Rokhlin, L.L.; Tarytina, I.E.

    1983-01-01

    Additional data on features of yttrium solid solutions composition in magnesium in the course of their decomposition investigation in the case of aging are obtianed. The investigation has been carried out on the base of a binary magnesium-yttrium alloy the composition of which has been close to maximum solubility (at eutectic temperature) and magnesium-yttrium alloys additionally doped with zinc. It is shown that higher yttrium solubility in solid magnesium than it has been expected, issueing from the difference in atomic radii of these metals indicates electron yttrium-magnesium atoms interaction. In oversaturated magnesium-yttrium solid solutions at earlier decomposition stages Mg 3 Cd type ordering is observed. At aging temperatures up to 250 deg C and long exposures corresponding to highest strengthening in oversaturated magnesium yttrium solid solutions a rhombic crystal lattice phase with three symmetric orientations is formed

  5. Scandium complexes with the tetraphenylethylene and anthracene dianions.

    Science.gov (United States)

    Ellis, John E; Minyaev, Mikhail E; Nifant'ev, Ilya E; Churakov, Andrei V

    2018-06-01

    The structural study of Sc complexes containing dianions of anthracene and tetraphenylethylene should shed some light on the nature of rare-earth metal-carbon bonding. The crystal structures of (18-crown-6)bis(tetrahydrofuran-κO)sodium bis(η 6 -1,1,2,2-tetraphenylethenediyl)scandium(III) tetrahydrofuran disolvate, [Na(C 4 H 8 O) 2 (C 12 H 24 O 6 )][Sc(C 26 H 20 ) 2 ]·2C 4 H 8 O or [Na(18-crown-6)(THF) 2 ][Sc(η 6 -C 2 Ph 4 ) 2 ]·2(THF), (1b), (η 5 -1,3-diphenylcyclopentadienyl)(tetrahydrofuran-κO)(η 6 -1,1,2,2-tetraphenylethenediyl)scandium(III) toluene hemisolvate, [Sc(C 17 H 13 )(C 26 H 20 )(C 4 H 8 O)]·0.5C 7 H 8 or [(η 5 -1,3-Ph 2 C 5 H 3 )Sc(η 6 -C 2 Ph 4 )(THF)]·0.5(toluene), (5b), poly[[(μ 2 -η 3 :η 3 -anthracenediyl)bis(η 6 -anthracenediyl)bis(η 5 -1,3-diphenylcyclopentadienyl)tetrakis(tetrahydrofuran)dipotassiumdiscandium(III)] tetrahydrofuran monosolvate], {[K 2 Sc 2 (C 14 H 10 ) 3 (C 17 H 13 ) 2 (C 4 H 8 O) 4 ]·C 4 H 8 O} n or [K(THF) 2 ] 2 [(1,3-Ph 2 C 5 H 3 ) 2 Sc 2 (C 14 H 10 ) 3 ]·THF, (6), and 1,4-diphenylcyclopenta-1,3-diene, C 17 H 14 , (3a), have been established. The [Sc(η 6 -C 2 Ph 4 ) 2 ] - complex anion in (1b) contains the tetraphenylethylene dianion in a symmetrical bis-η 3 -allyl coordination mode. The complex homoleptic [Sc(η 6 -C 2 Ph 4 ) 2 ] - anion retains its structure in THF solution, displaying hindered rotation of the coordinated phenyl rings. The 1D 1 H and 13 C{ 1 H}, and 2D COSY 1 H- 1 H and 13 C- 1 H NMR data are presented for M[Sc(Ph 4 C 2 ) 2 ]·xTHF [M = Na and x = 4 for (1a); M = K and x = 3.5 for (2a)] in THF-d 8 media. Complex (5b) exhibits an unsymmetrical bis-η 3 -allyl coordination mode of the dianion, but this changes to a η 4 coordination mode for (1,3-Ph 2 C 5 H 3 )Sc(Ph 4 C 2 )(THF) 2 , (5a), in THF-d 8 solution. A 45 Sc NMR study of (2a) and UV-Vis studies of (1a), (2a) and (5a) indicate a significant covalent contribution to the Sc-Ph 4 C 2 bond character. The unique Sc ate complex, (6

  6. Method for production of transparent yttrium oxide

    International Nuclear Information System (INIS)

    Dutta, S.K.; Gazza, G.A.

    1975-01-01

    The method comprises vacuum hot pressing the yttrium oxide (Y 2 O 3 ) powder in a graphite die at temperatures of between 1300 to 1500 0 C and uniaxial pressures of between 5000 to 7000 psi, for a period of 1 to 2 hours. (U.S.)

  7. New hydrotalcite-like compounds containing yttrium

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.M.; Barriga, C.; Ulibarri, M.A. [Universidad de Cordoba (Spain)] [and others

    1997-01-01

    The synthesis of hydrotalcite-type compounds containing yttrium was carried out by the coprecipitation of Mg(II), Al(III), and Y(III) cations at 60 degrees C with strong alkaline solutions. Thermal treatments were applied and changes studied.

  8. Bonding in scandium monosulfide a NaCl crystal type

    International Nuclear Information System (INIS)

    Merrick, J.A.

    1980-08-01

    The transition temperature of an order-disorder transition in Sc 0 81 S (R anti 3m to Fm3m) occurs at 700 0 C. A group of ordered sublattices on the NaCl-type lattice (Fm3m) was generated and a Madelung energy and configurational entropy were calculated for each sublattice assuming the ions to be Sc 2 48+ and S 2- . Mean field and pair interaction approximations were used to model long-range and short-range orderings, respectively. The electrostatic model fails to predict the observed short-range and long-range orderings. The high temperature vaporization of ScP was investigated by mass spectrometry and target collection Knudsen effusion at 1767 to 2209K. The composition ScP 1 00 vaporizes congruently to the gaseous species Sc, P, and P 2 . A temperature independent third law enthalpy of atomization (ΔH 0 /sub atom,298/ = 252.2 +- 2.8 kcal mole -1 ) has a value approx. 12 kcal larger than that reported for ScS. Nonrelativistic, nonself-consistent LAPW band structure calculations are reported for ScS. XPS and UPS measurements are reported for Sc 2 S 3 and several compositions Sc/sub 1-x/S (0.0 less than or equal to x less than or equal to 0.2). The Sc and S 2p binding energies (XPS) obtained for the defect scandium monosulfides are very close to those found in the pure elements, suggesting covalent bonding. The Sc 2p energy region has an interesting satellite structure

  9. Nonaqueous method for dissolving lanthanide and actinide metals

    International Nuclear Information System (INIS)

    Crisler, L.R.

    1975-01-01

    Lanthanide and actinide beta-diketonate complex molecular compounds are produced by reacting a beta-diketone compound with a lanthanide or actinide element in the elemental metallic state in a mixture of carbon tetrachloride and methanol

  10. The effects of aluminum or scandium on the toughness, density and ...

    African Journals Online (AJOL)

    The effects of the substitution of aluminum or scandium on the density, toughness as well as the stability of the phases formed by such an addition on platinum, iridium, rhodium and palladium metals were evaluated with the density functional quantum mechanical calculation methods. All the metals had four atoms per ...

  11. Study of competitive complexing in scandium(3)-xylenol-orange-hydroxyethyliminodiacetic acid system

    International Nuclear Information System (INIS)

    Kornev, V.I.; Mukanov, I.P.; Artem'eva, O.A.

    1976-01-01

    The competitive complexing in the system scandium(3)-xylene orange (XO)-hydroxyethyliminodiacetic acid (H 3 L) has been studied. Ligands act as competitive particles. It has been established preliminarily that introduction of H 3 L into the solution containing a mixture of Sc and Xo changes considerably the absorption spectra of the coloured complex. Weakening of light absorption indicates that the coloured complex with XO is destructed and colourless hydroxyethyliminodiacetate of scandium is formed. The formation of scandium hydroxyethyliminoacetate has been studied spectrophotometrically by equilibrium between the complexes. The dependence of optical density on pH, when the concentrations of reagents are constant, as well as on concetration of H 3 L has been studied. The composition of the complex (1:1) formed at pH 3.2 has been established graphically and the constant of the complex ScHL + instability has been calculated (PKsub(H)=10.69+-0.45). It has been shown that H 3 L, when interacting with scandium, behaves as dibasic ligand. It is most probable that during complex formation the hydrogen ion of the hydroxygroup is not replaced, although the participation of hydroxygroup in coordination is possible due to a donor-acceptor bond

  12. In situ observation of the reaction of scandium and carbon by neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Juarez-Arellano, Erick A., E-mail: eajuarez@unpa.edu.m [Institut fuer Geowissenschaften, Universitaet Frankfurt, Altenhoeferallee 1, 60438 Frankfurt a.M. (Germany); Universidad del Papaloapan, Circuito Central 200, Parque Industrial, Tuxtepec 68301 (Mexico); Winkler, Bjorn [Institut fuer Geowissenschaften, Universitaet Frankfurt, Altenhoeferallee 1, 60438 Frankfurt a.M. (Germany); Vogel, Sven C. [Los Alamos National Laboratory, Lujan Center. Mail Stop H805, Los Alamos, NM 87545 (United States); Senyshyn, Anatoliy [Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universitaet Muenchen, Lichtenbergstr. 1, D-85747 Garching (Germany); Materialwissenschaft, TU Darmstadt, Petersensstr. 23, D-64287 Darmstadt (Germany); Kammler, Daniel R. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Avalos-Borja, Miguel [CNyN, UNAM, A. Postal 2681, Ensenada, B.C. (Mexico)

    2011-01-05

    Research highlights: {yields} Exist two ScC cubic phases with B1-structure type differing in site occupancy of C. {yields} A new orthorhombic scandium carbide phase is formed at 1473(50) K. {yields} The recrystallization of alpha-Sc occurs between 1000 and 1223 K. - Abstract: The formation of scandium carbides by reaction of the elements has been investigated by in situ neutron diffraction up to 1823 K. On heating, the recrystallization of {alpha}-Sc occurs between 1000 and 1223 K. The formation of Sc{sub 2}C and ScC (NaCl-B1 type structure) phases has been detected at 1323 and 1373 K, respectively. The formation of a new orthorhombic scandium carbide phase was observed at 1473(50) K. Once the scandium carbides are formed they are stable upon heating or cooling. No other phases were detected in the present study, in which the system was always carbon saturated. The thermal expansion coefficients of all phases have been determined, they are constant throughout the temperature interval studied.

  13. New Lanthanide Alkynylamidinates and Diiminophosphinates

    Directory of Open Access Journals (Sweden)

    Farid M. Sroor

    2015-11-01

    Full Text Available This contribution reports the synthesis and structural characterization of several new lithium and lanthanide alkynylamidinate complexes. Treatment of PhC≡CLi with N,N′-diorganocarbodiimides, R–N=C=N–R (R = iPr, Cy (cyclohexyl, in THF or diethyl ether solution afforded the lithium-propiolamidinates Li[Ph–C≡C–C(NCy2] S (1: R = iPr, S = THF; 2: R = Cy, S = THF; 3: R = Cy, S = Et2O. Single-crystal X-ray diffraction studies of 1 and 2 showed the presence of typical ladder-type dimeric structures in the solid state. Reactions of anhydrous LnCl3 (Ln = Ce, Nd, Sm or Ho with 2 in a 1:3 molar ratio in THF afforded a series of new homoleptic lanthanide tris(propiolamidinate complexes, [Ph–C≡C–C(NCy2]3Ln (4: Ln = Ce; 5: Ln = Nd; 6: Ln = Sm; 7: Ln = Ho. The products were isolated in moderate to high yields (61%–89% as brightly colored, crystalline solids. The chloro-functional neodymium(III bis(cyclopropylethynylamidinate complex [{c-C3H5–C≡C–C(NiPr2}2Ln(µ-Cl(THF]2 (8 was prepared from NdCl3 and two equiv. of Li[c-C3H5–C≡C–C(NiPr2] in THF and structurally characterized. A new monomeric Ce(III-diiminophosphinate complex, [Ph2P(NSiMe32]2Ce(µ-Cl2Li(THF2 (9, has also been synthesized in a similar manner from CeCl3 and two equiv. of Li[Ph2P(NSiMe32]. Structurally, this complex resembles the well-known “ate” complexes (C5Me52Ln(µ-Cl2Li(THF2. Attempts to oxidize compound 9 using trityl chloride or phenyliodine(III dichloride did not lead to an isolable cerium(IV species.

  14. NMR study of structure of lanthanide complexes in solution

    International Nuclear Information System (INIS)

    Choppin, G.R.

    1976-01-01

    The diagnostic value PMR studies of diamagnetic lanthanide complexes to define the nature of the species in the lanthanide-pyruvate system is discussed. The use of NMR spectra of both diamagnetic and paramagnetic lanthanide complexes to obtain detailed structural information is reviewed

  15. Solution chemistry of lanthanide complexes

    International Nuclear Information System (INIS)

    Brittain, H.G.

    1979-01-01

    Intermolecular energy transfer from Tb 3+ to Eu 3+ , luminescence intensity measurements, potentiometric titrations, differential absorption spectroscopy, and spectroscopic titrations were all used to study the binding of lanthanide ions by serine and threonine. At low pH (3.0 to 6.0) the complexes are mononuclear and ligand is only weakly bound. In the pH interval of 6.0 to 8.5 stronger interaction takes place between the ligand and the metal (with possible coordination of the undissociated hydroxyl group), and self-association of complexes becomes important. Above pH 8.5, base hydrolysis of the complexes leads to highly associated species in solution and shortly above this pH an insoluble precipitate is formed. It was found that energy could be transferred from Tb 3+ to Eu 3+ more efficiently among complexes prepared from racemic ligands than in complexes made from resolved ligand, but this stereoselectivity was only observed at pH values greater than 6.5 and in solutions having a 1:10 ratio of metal-to-ligand. No stereoselectivity was found in solutions having 1:5 ratios, and this observation was explained by the existence of 1:2 metal-ligand complexes existing in solutions having the higher ratio of metal-to-ligand (only 1:1 complexes are then found at lower ratios of metal-to-ligand). (author)

  16. Magnetic structure of holmium-yttrium superlattices

    DEFF Research Database (Denmark)

    Jehan, D.A.; McMorrow, D.F.; Cowley, R.A.

    1993-01-01

    We present the results of a study of the chemical and magnetic structures of a series of holmium-yttrium superlattices and a 5000 angstrom film of holmium, all grown by molecular-beam epitaxy. By combining the results of high-resolution x-ray diffraction with detailed modeling, we show...... that the superlattices have high crystallographic integrity: the structural coherence length parallel to the growth direction is typically almost-equal-to 2000 angstrom, while the interfaces between the two elements are well defined and extend over approximately four lattice planes. The magnetic structures were...... determined using neutron-scattering techniques. The moments on the Ho3+ ions in the superlattices form a basal-plane helix. From an analysis of the superlattice structure factors of the primary magnetic satellites, we are able to determine separately the contributions made by the holmium and yttrium...

  17. Treatment of acromegaly by yttrium implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hibbert, J.; Shaheen, O.H.

    1977-01-01

    Yttrium implantation is one of the many ways of treating acromegaly. The advantages are the minor nature of the procedure and the fact that pituitary replacement is not as commonly required as after hypophysectomy. Thus in young female patients menstruation may be resumed following treatment and pregnancy has occurred. The procedure is not as free from complications as external irradiation but the response is more satisfactory.

  18. Yttrium and rare earths separation by ion exchange resin

    International Nuclear Information System (INIS)

    Pinatti, D.G.; Ayres, M.J.G.; Ribeiro, S.; Silva, G.L.J.P.; Silva, M.L.C.P.; Martins, A.H.

    1988-01-01

    The experimental results of yttrium and rare earths separation from Brazilian xenotime are presented. The research consist in five stage: 1) Preparation of yttrium, erbium and lutetium standard solutions, from solubilization of pure oxides 2) yttrium and rare earths separation by ion exchange chromatrography 3) Separation and recovery of EDTA 4) Precipitation and calcination and 4) Analytical control of process. (C.G.C.) [pt

  19. Lanthanides in the frame of Molecular Magnetism

    Directory of Open Access Journals (Sweden)

    Gatteschi D.

    2014-07-01

    Full Text Available Molecular magnetism is producing new types of materials which cover up to date aspects of basic science together with possible applications. This article highlights recent results from the point of view of lanthanides which are now intensively used to produce single molecule magnets, single chain and single ion magnets. After a short introduction reminding the main steps of development of molecular magnetism, the basic properties of lanthanides will be covered highlighting important features which are enhanced by the electronic structure of lanthanides, like spin frustration and chirality, anisotropy and non collinear axes in zero and one dimensional materials. A paragraph of conclusions will discuss what has been done and theperspectives to be expected.

  20. Curvature of the Lanthanide Contraction: An Explanation

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, Kenneth; Wellman, Daniel; Sgarlata, Carmelo; Hill, Aru

    2009-12-21

    A number of studies have shown that for isostructural series of the lanthanides (elements La through Lu), a plot of equivalent metal-ligand bond lengths versus atomic number differs significantly from linearity and can be better fit as a quadratic equation. However, for hydrogen type wave functions, it is the inverse of the average distance of the electron from the nucleus (an estimate of size) that varies linearly with effective nuclear charge. This generates an apparent quadratic dependence of radius with atomic number. Plotting the inverse of lanthanide ion radii (the observed distance minus the ligand size) as a function of effective nuclear charge gives very good linear fits for a variety of lanthanide complexes and materials. Parameters obtained from this fit are in excellent agreement with the calculated Slater shielding constant, k.

  1. Yttrium addition for high temperatures stainless steel

    International Nuclear Information System (INIS)

    Furtado, Nelson Cesar Chaves Pinto

    1997-07-01

    The current work studied the effect of Yttrium on the microstructure of 2% Nb, modified - HP steel, with respect to its mechanical properties. Alloys were prepared with nominal Yttrium additions of 0,1% and 0,25%. Microstructural analyses and mechanical tests were undertaken in the as-cast condition and after ageing for 100 h at 700 deg C, 900 deg C and 1100 deg C. Structural characterization was performed by optical microscopy, scanning and transmission electron microscopy (SEM/TEM/EDS), X-ray diffractometry and X-ray photoelectron spectroscopy (XPS). Tensile testing was performed at room temperature and 871 deg C and creep testing at 925 deg C at a loading of 55 MPa. The material produced exhibited superior mechanical properties and surface oxidation resistance than traditional alloys of this class, even through gravity cast in a magnetic furnace. Agglomerates of Yttrium-rich phases were identifies in both as-cast and aged specimens, always associated with chromium carbides of characteristic morphologies. These morphologies, combined with the microstructural constituents, may have established the factors which resulted in the improved metallurgical stability of these alloys under the experimental testing conditions and temperatures which simulated real industrial service conditions and temperatures. (author)

  2. Optimization of the radio lanthanides separation device

    International Nuclear Information System (INIS)

    Vera T, A. L.

    2009-01-01

    At present, cancer is a major cause of mortality in our country, therefore, its prevention, diagnosis and treatment are vital to health systems. The cancer treatment and other diseases, from monoclonal antibodies, peptides, or amino macro aggregates marked with beta particle emitting radionuclides, is a highly promising field. The radioactive lanthanides: Pm, Tb, Ho, and Lu are beta emitters, which possess nuclear and chemical properties, which have shown their feasibility as radioisotopes of radiotherapeutic use. However, these radioisotopes are not available commercially in this connection, the Research Laboratory of Radioactive Materials of the National Institute of Nuclear Research, has developed the methodology of production of these radioisotopes and based on this work is designed, constructed and installed the radio lanthanides separation device for the radioisotopes production routinely. This device is part of the cell, , which has and auxiliary air service, an extraction system and is protected with a 10 cm of lead shielding. The radio lanthanides separation device is manual and easy to handle. The main function of this equipment is the radio lanthanides separation from extractive chromatography through packed columns with a commercial resin (Ln SPS) and coated on the top and bottom by fiberglass. The radio lanthanides separation device comprises a main carrousel where the separation columns and elution containers are mounted. It also has a system of open irradiation vials, carrier samples for columns and glassware. This paper presents a detailed description of the radio lanthanides separation device and its management, which allows the radioisotopes production Pm, Tb, Ho, and Lu from the separation of its parents Nd, Dy, Gd, and Yb respectively. (Author)

  3. Gamma ray induced decomposition of lanthanide nitrates

    International Nuclear Information System (INIS)

    Joshi, N.G.; Garg, A.N.

    1992-01-01

    Gamma ray induced decomposition of the lanthanide nitrates, Ln(NO 3 ) 3 .xH 2 O where Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Tm and Yb has been studied at different absorbed doses up to 600 kGy. G(NO 2 - ) values depend on the absorbed dose and the nature of the outer cation. It has been observed that those lanthanides which exhibit variable valency (Ce and Eu) show lower G-values. An attempt has been made to correlate thermal and radiolytic decomposition processes. (author). 20 refs., 3 figs., 1 tab

  4. Factors in the complexation of lanthanides

    International Nuclear Information System (INIS)

    Choppin, G.R.

    1976-01-01

    The lanthanide cations are classified as hard acids and thus will coordinate strongly with oxygen and fluorine donor atoms. The electrostatic model is applied to lanthanide complexes with the dielectric constant as a parameter; the plot of ΔG vs sum of ionic radii confirm the ionic nature of the bonding. The enthalpy and entropy changes are shown to compensate each other to produce an almost linear variation in the free energy of complexation. Outer-sphere and inner-sphere complexation is discussed

  5. The geochemistry and mobility of the lanthanides in marine sediments

    International Nuclear Information System (INIS)

    Elderfield, H.

    1988-07-01

    A study has been made to evaluate lanthanide mobility in sediments directly by measuring concentrations of 10 lanthanide elements in sediments and pore waters. Due to the very low concentrations of the lanthanides in sea water relative to marine sediments, evidence of lanthanide mobilization is usually difficult to detect from studies of solid-phase geochemistry. Results show that the lanthanides can be extremely mobile. Concentrations in pore waters up to 100 times sea water concentrations have been measured. The conclusions are tentative but the present data suggest that the lanthanides are mobilized during oxidation of organic-rich sediments and are relocated in part in association with secondary Fe-rich phases. The behaviour of Ce is, predictably, somewhat different from the other lanthanides and may be more mobile as a consequence of its redox chemistry. (author)

  6. Studies of Lanthanide Transport in Metallic Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinsuo; Taylor, Christopher

    2018-04-02

    Metallic nuclear fuels were tested in fast reactor programs and performed well. However, metallic fuels have shown the phenomenon of FCCI that are due to deleterious reactions between lanthanide fission products and cladding material. As the burnup is increased, lanthanide fission products that contact with the cladding could react with cladding constituents such as iron and chrome. These reactions produce higher-melting intermetallic compounds and low-melting alloys, and weaken the mechanical integrity. The lanthanide interaction with clad in metallic fuels is recognized as a long-term, high-burnup cause of the clad failures. Therefore, one of the key concerns of using metallic fuels is the redistribution of lanthanide fission products and migration to the fuel surface. It is believed that lanthanide migration is in part due to the thermal gradient between the center and the fuel-cladding interface, but also largely in part due to the low solubility of lanthanides within the uranium-based metal fuel. PIE of EBR-II fuels shows that lanthanides precipitate directly and do not dissolve to an appreciable extent in the fuel matrix. Based on the PIE data from EBR-II, a recent study recommended a so-called “liquid-like” transport mechanism for lanthanides and certain other species. The liquid-like transport model readily accounts for redistribution of Ln, noble metal fission products, and cladding components in the fuel matrix. According to the novel mechanism, fission products can transport as solutes in liquid metals, such as liquid cesium or liquid cesium–sodium, and on pore surfaces and fracture surfaces for metals near their melting temperatures. Transport in such solutions is expected to be much more rapid than solid-state diffusion. The mechanism could explain the Ln migration to the fuel slug peripheral surface and their deposition with a sludge-like form. Lanthanides have high solubility in liquid cesium but have low solubility in liquid sodium. As a

  7. Sol gel synthesis for preparation of yttrium aluminium garnet

    NARCIS (Netherlands)

    Vrolijk, J.W.G.A.; Willems, J.W.M.M.; Metselaar, R.; With, de G.; Terpstra, R.A.; Metselaar, R.

    1989-01-01

    Sol-gel—synthesis for preparation of pure yttrium aluminium garnet powder with small grain size is subject of this ongoing study. Starting materials were sulfates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3A1SO1Z) pH during hydrolysis as well as temperature during calcination and

  8. Process Design Aspects for Scandium-Selective Leaching of Bauxite Residue with Sulfuric Acid

    OpenAIRE

    Konstantinos Hatzilyberis; Theopisti Lymperopoulou; Lamprini-Areti Tsakanika; Klaus-Michael Ochsenkühn; Paraskevas Georgiou; Nikolaos Defteraios; Fotios Tsopelas; Maria Ochsenkühn-Petropoulou

    2018-01-01

    Aiming at the industrial scale development of a Scandium (Sc)-selective leaching process of Bauxite Residue (BR), a set of process design aspects has been investigated. The interpretation of experimental data for Sc leaching yield, with sulfuric acid as the leaching solvent, has shown significant impact from acid feed concentration, mixing time, liquid to solids ratio (L/S), and number of cycles of leachate re-usage onto fresh BR. The thin film diffusion model, as the fundamental theory for l...

  9. Diagrammatic Representation of Electronic Correlations in Photoionization Process: Application to Scandium

    International Nuclear Information System (INIS)

    Liu Mengmeng; Ma Xiaoguang

    2011-01-01

    The conversion rules under which an algebraic expression can be obtained from a corresponding photoionization Goldstone diagram have been given systematically in the present work. The electronic correlations in the photoionization processes then could be studied diagrammatically. The application to atomic scandium shows that the present theoretical scheme can give reasonable photoionization cross sections, which agree well with the experimental results. (atomic and molecular physics)

  10. Pressure-induced polyamorphism in lanthanide-solute metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Li, Liangliang; Li, Renfeng; Liu, Haozhe [Harbin Institute of Technology, Harbin (China); Center for High Pressure Science Technology Advanced Research, Changchun (China); Wang, Luhong [Harbin Institute of Technology, Harbin (China); Qu, Dongdong [School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, QLD (Australia); Zhao, Haiyan [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL (United States); Center for Advanced Energy Studies, University of Idaho, Idaho Falls, ID (United States); Chapman, Karena W.; Chupas, Peter J. [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL (United States)

    2017-06-15

    The electronic structure inheritance of lanthanide-solvent atoms in lanthanide-based metallic glasses has been proposed. Is a polyamorphism possible in lanthanide-solute metallic glasses? So far, polyamorphic phase transitions in metallic glass containing lanthanide have been observed only in lanthanide-solvent metallic glasses. Here, a pressure-induced transition between two distinct amorphous states, accompanied by a 7% volume collapse at ambient pressure, was observed in La{sub 43.4}Pr{sub 18.6}Al{sub 14}Cu{sub 24} metallic glass, with low lanthanide content, by using in situ X-ray total scattering method. The transformation also indicated by changes in short range and medium range order. Thus, it is proposed that the lanthanide-solute metallic glasses also inherit 4f electronic transition from pure lanthanide element in polyamorphic transition. This discovery offers a supplement to research on lanthanide-based metallic glasses, which further provides a new perspective of the polyamorphic transformation in metallic glasses containing lanthanide element. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Pilot-scale recovery of rare earths and scandium from phosphogypsum and uranium leachates

    Directory of Open Access Journals (Sweden)

    Mashkovtsev Maxim

    2016-01-01

    Full Text Available Ural Federal University (UrFU and VTT have performed joint research on development of industrial technologies for the extraction of REM and Scandium compounds from phosphogypsum and Uranium ISL leachate solutions. Leaching-absorption experiments at UrFU have been supported with multicomponent solution modelling by VTT. The simulations have been performed with VTT’s ChemSheet/Balas program and can be used for speciation calculations in the lixiviant solution. The experimental work combines solvent extraction with advanced ion exchange methodology in a pilot facility capable of treating 5 m3 solution per hour. Currently, the plant produces cerium carbonate, lanthanum oxide, neodymium oxide and concentrate of heavy rare earth metals. A batch of 45 t solids has been processed with the gain of 100 kg’s of REM concentrate. A mini-pilot plant with productivity above 50 liters per hour has been applied to recover scandium oxide and REE concentrates from the uranium ISL solution. As the preliminary product contains radioactivity (mainly strontium, an additional decontamination and cleaning of both concentrates by extraction has rendered a necessity. Finally a purified 99% concentrate of scandium oxide as well as 99% rare earth concentrate are received.

  12. Effect of scandium on the phase composition and mechanical properties of ABM alloys

    Science.gov (United States)

    Molchanova, L. V.

    2010-09-01

    The effect of scandium on the composition and mechanical properties of ABM-1 alloys (Al-30% Be-5% Mg) is studied. The scandium content is varied from 0.1 to 0.5 wt %. It is established that, in the studied part of the Al-Be-Mg-Sc system, an aluminum solid solution (Al) and the ScBe13 compound are in equilibrium with a beryllium solid solution (Be). Magnesium dissolves in both the aluminum component and the ScBe13 compound. The strengthening effect related to the decomposition of the solid solution and the precipitation of Al3Sc cannot be extended to the strengthening of ABM-type alloys. Additions of 0.1-0.15 wt % Sc only weakly improve the mechanical properties of the alloys due to the refinement of beryllium-component grains. At high scandium contents, the strength increases insignificantly due to primary precipitation of ScBe13 and the plasticity decreases simultaneously.

  13. Influence of scandium on the pitting behaviour of Al-Zn-Mg-Cu alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wloka, J. [Department of Materials Sciences, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen (Germany); Virtanen, S. [Department of Materials Sciences, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen (Germany)], E-mail: virtanen@ww.uni-erlangen.de

    2007-11-15

    In this paper the influence of small scandium additions (<0.26 wt.%) on the corrosion properties of the high-strength Al-Zn-Mg-Cu alloy AA7010 is investigated. The addition of scandium (in combination with the grain refiner Zr) leads to the formation of Al{sub 3}Sc{sub x}Zr{sub 1-x} phases. These coarse particles disturb the grain structure near the particle/matrix interface, which facilitates the initiation of localized corrosion in potentio-dynamic scans. Microelectrochemical investigations revealed a slightly cathodic character of these particles and a passive range beyond the breakdown potential of the matrix. Mass loss measurements show that the addition of scandium increases the mass loss during the initial period. The corrosion morphology was investigated with optical and scanning electron microscopy. The composition of the phases was determined with energy-dispersive X-ray analysis. Micro-capillary measurements were performed to investigate the electrochemical properties of single phases surrounded by matrix.

  14. Abscopal Effects and Yttrium-90 Radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Ghodadra, Anish; Bhatt, Sumantha [University Pittsburgh School of Medicine, Department of Radiology (United States); Camacho, Juan C. [Emory University School of Medicine, Department of Radiology and Imaging Sciences (United States); Kim, Hyun S., E-mail: kevin.kim@yale.edu [University Pittsburgh School of Medicine, Department of Radiology (United States)

    2016-07-15

    We present the case of an 80-year-old male with squamous cell carcinoma with bilobar hepatic metastases who underwent targeted Yttrium-90 radioembolization of the right hepatic lobe lesion. Subsequently, there was complete regression of the nontargeted, left hepatic lobe lesion. This may represent the first ever reported abscopal effect in radioembolization. The abscopal effect refers to the phenomenon of tumor response in nontargeted sites after targeted radiotherapy. In this article, we briefly review the immune-mediated mechanisms responsible for the abscopal effect.

  15. Nonlinear FMR spectra in yttrium iron garnet

    Directory of Open Access Journals (Sweden)

    Yu.M. Bunkov, P.M. Vetoshko, I.G. Motygullin, T.R. Safin, M.S. Tagirov, N.A. Tukmakova

    2015-12-01

    Full Text Available Results of demagnetizing effect studies in yttrium iron garnet Y3Fe5O12 thin films are reported. Experiments were performed on X-Band of electron paramagnetic resonance spectrometer at room temperature. The ferromagnetic resonance (FMR spectra were obtained for one-layer single crystal YIG films for different values of the applied microwave power. Nonlinear FMR spectra transformation by the microwave power increasing in various directions of magnetic field sweep was observed. It is explained by the influence of the demagnetization action of nonequilibrium magnons.

  16. Cerium and yttrium oxide nanoparticles are neuroprotective

    International Nuclear Information System (INIS)

    Schubert, David; Dargusch, Richard; Raitano, Joan; Chan, S.-W.

    2006-01-01

    The responses of cells exposed to nanoparticles have been studied with regard to toxicity, but very little attention has been paid to the possibility that some types of particles can protect cells from various forms of lethal stress. It is shown here that nanoparticles composed of cerium oxide or yttrium oxide protect nerve cells from oxidative stress and that the neuroprotection is independent of particle size. The ceria and yttria nanoparticles act as direct antioxidants to limit the amount of reactive oxygen species required to kill the cells. It follows that this group of nanoparticles could be used to modulate oxidative stress in biological systems

  17. Systemic analysis of thermodynamic properties of lanthanide halides

    International Nuclear Information System (INIS)

    Mirsaidov, U.; Badalov, A.; Marufi, V.K.

    1992-01-01

    System analysis of thermodynamic characteristics of lanthanide halides was carried out. A method making allowances for the influence of spin and orbital moments of momentum of the main states of lanthanide trivalent ions in their natural series was employed. Unknown in literature thermodynamic values were calculated and corrected for certain compounds. The character of lanthanide halide thermodynamic parameter change depending on ordinal number of the metals was ascertained. Pronouncement of tetrad-effect in series of compounds considered was pointed out

  18. Radical-lanthanide ferromagnetic interaction in a T bIII bis-phthalocyaninato complex

    Science.gov (United States)

    Komijani, Dorsa; Ghirri, Alberto; Bonizzoni, Claudio; Klyatskaya, Svetlana; Moreno-Pineda, Eufemio; Ruben, Mario; Soncini, Alessandro; Affronte, Marco; Hill, Stephen

    2018-02-01

    Recent studies have highlighted the importance of organic ligands in the field of molecular spintronics, via which delocalized electron-spin density can mediate magnetic coupling to otherwise localized 4 f moments of lanthanide ions, which show tremendous potential for single-molecule device applications. To this end, high-field/high-frequency electron paramagnetic resonance (EPR) spectroscopy is employed to study a neutral terbium bis-phthalocyaninato metalorganic complex, [TbPc2 ] 0, with the aim of understanding the magnetic interaction between the Ising-like moment of the lanthanide ion and the unpaired spin density on the coordinating organic radical ligand. The measurements were performed on a previously unknown [TbPc2 ] 0 structural phase crystallizing in the Pnma space group. EPR measurements on powder samples of [TbPc2 ] 0 reveal an anisotropic spectrum, which is attributed to the spin-1/2 radical coupled weakly to the EPR-silent T bIII ion. Extensive double-axis rotation studies on a single crystal reveal two independent spin-1/2 signals with differently oriented (albeit identical) uniaxial g -tensors, in complete agreement with x-ray structural studies that indicate two molecular orientations within the unit cell. The easy-axis nature of the radical EPR spectra thus reflects the coupling to the Ising-like T bIII moment. This is corroborated by studies of the isostructural [YPc2 ] 0 analog (where Y is nonmagnetic yttrium), which gives a completely isotropic radical EPR signal. The experimental results for the terbium complex are well explained on the basis of an effective model that introduces a weak ferromagnetic Heisenberg coupling between an isotropic spin-1/2 and an anisotropic spin-orbital moment, J =6 , that mimics the known, strong easy-axis Tb ⋯P c2 crystal-field interaction.

  19. Yttrium synovectomy: a meta-analysis of the literature

    International Nuclear Information System (INIS)

    Jones, G.

    1993-01-01

    Yttrium synovectomy for chronic synovitis of the knee enjoys widespread usage in Australia with approximately 400 patients receiving yttrium-90 in 1991. Despite abundant anecdotal evidence of its efficacy there is a paucity of controlled trials and those that have been done have produced conflicting results and have been of insufficient sample size. To critically and quantitatively evaluate the published English literature on comparative trials of yttrium-90 therapy for chronic synovitis of the knee, the technique of meta-analysis was utilised. The literature search was carried out using the MeSH terms of synovectomy and knee; and yttrium. This was augmented by referring to reviews, current textbooks and back-references. Outcome measures varied between trials but could be grouped as treatment success. The Peto modification of Mantel and Haenszl was used for statistical pooling of data yielding a pooled odds ratio (OR). The literature search revealed ten controlled trials of which two were excluded from further analysis. It was found that yttrium was superior to placebo (OR 2.42, 95% CI 1.02-5.73) but it is recommended that this result should be interpreted with caution due to possible publication bias. It is concluded that there is insufficient evidence from comparative trials of yttrium in the English literature to show that yttrium synovectomy is convincingly superior to triamcinolone (OR 1.89, 95% CI 0.81-10.55) or other active modalities (OR 1.04, 95% CI 0.72-1.52). 25 refs., 4 tabs

  20. Lanthanide doped strontium-barium cesium halide scintillators

    Science.gov (United States)

    Bizarri, Gregory; Bourret-Courchesne, Edith; Derenzo, Stephen E.; Borade, Ramesh B.; Gundiah, Gautam; Yan, Zewu; Hanrahan, Stephen M.; Chaudhry, Anurag; Canning, Andrew

    2015-06-09

    The present invention provides for a composition comprising an inorganic scintillator comprising an optionally lanthanide-doped strontium-barium, optionally cesium, halide, useful for detecting nuclear material.

  1. Ultrasmall lanthanide oxide nanoparticles for biomedical imaging and therapy

    CERN Document Server

    Lee, Gang Ho

    2014-01-01

    Most books discuss general and broad topics regarding molecular imagings. However, Ultrasmall Lanthanide Oxide Nanoparticles for Biomedical Imaging and Therapy, will mainly focus on lanthanide oxide nanoparticles for molecular imaging and therapeutics. Multi-modal imaging capabilities will discussed, along with up-converting FI by using lanthanide oxide nanoparticles. The synthesis will cover polyol synthesis of lanthanide oxide nanoparticles, Surface coatings with biocompatible and hydrophilic ligands will be discussed and TEM images and dynamic light scattering (DLS) patterns will be

  2. Giant exchange interaction in mixed lanthanides

    Science.gov (United States)

    Vieru, Veacheslav; Iwahara, Naoya; Ungur, Liviu; Chibotaru, Liviu F.

    2016-01-01

    Combining strong magnetic anisotropy with strong exchange interaction is a long standing goal in the design of quantum magnets. The lanthanide complexes, while exhibiting a very strong ionic anisotropy, usually display a weak exchange coupling, amounting to only a few wavenumbers. Recently, an isostructural series of mixed (Ln = Gd, Tb, Dy, Ho, Er) have been reported, in which the exchange splitting is estimated to reach hundreds wavenumbers. The microscopic mechanism governing the unusual exchange interaction in these compounds is revealed here by combining detailed modeling with density-functional theory and ab initio calculations. We find it to be basically kinetic and highly complex, involving non-negligible contributions up to seventh power of total angular momentum of each lanthanide site. The performed analysis also elucidates the origin of magnetization blocking in these compounds. Contrary to general expectations the latter is not always favored by strong exchange interaction. PMID:27087470

  3. Intercalation of lanthanide trichlorides in graphite

    International Nuclear Information System (INIS)

    Stumpp, E.; Nietfeld, G.

    1979-01-01

    The reactions of the whole series of lanthanide trichlorides with graphite have been investigated. Intercalation compounds have been prepared with the chlorides of Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, Y whereas LaCl 3 , CeCl 3 , PrCl 3 and NdCl 3 do not intercalate. The compounds were characterized by chemical and X-ray analysis. The amount of c-axis increase is consistent with the assumption that the chlorides are intercalated in form of a chloride layer sandwich resmbling the sheets in YCl 3 . The chlorides which do not intercalate crystallize in the UCl 3 structure having 3 D arrangements of ions. Obviously, these chlorides cannot form sheets between the carbon layers. The ability of AlCl 3 to volatilize lanthanide chlorides through complex formation in the gas phase can be used to increase the intercalation rate strikingly. (author)

  4. Diagnostic study about lanthanides (rare earths)

    International Nuclear Information System (INIS)

    Ribeiro, G.F.

    1985-01-01

    The world situation of rare earths (lanthanides) is evaluated, and a comparison of the Brazilian situation in respect to other countries is established, concerning the following aspects: geology of mineral deposits; main sources, uses, reserves and production; their consumption, prices and state-of-art of geological researches and industrial processes for physical and chemical separation / concentration of these elements. (C.L.B.) [pt

  5. Effective core potential methods for the lanthanides

    International Nuclear Information System (INIS)

    Cundari, T.R.; Stevens, W.J.

    1993-01-01

    In this paper a complete set of effective core potentials (ECPs) and valence basis sets for the lanthanides (Ce to Lu) are derived. These ECPs are consistent not only within the lanthanide series, but also with the third-row transition metals which bracket them. A 46-electron core was chosen to provide the best compromise between computational savings and chemical accuracy. Thus, the 5s and 5p are included as ''outer'' core while all lower energy atomic orbitals (AOs) are replaced with the ECP. Generator states were chosen from the most chemically relevant +3 and +2 oxidation states. The results of atomic calculations indicate that the greatest error vs highly accurate numerical potential/large, even-tempered basis set calculations results from replacement of the large, even-tempered basis sets with more compact representations. However, the agreement among atomic calculations remains excellent with both basis set sizes, for a variety of spin and oxidation states, with a significant savings in time for the optimized valence basis set. It is expected that the compact representation of the ECPs and valence basis sets will eventually encourage their use by computational chemists to further explore the bonding and reactivity of lanthanide complexes

  6. Hardening mechanisms of spray formed Al-Zn-Mg-Cu alloys with scandium and other elemental additions

    International Nuclear Information System (INIS)

    Sharma, M.M.; Amateau, M.F.; Eden, T.J.

    2006-01-01

    The hardening mechanisms in spray formed Al-Zn-Mg-Cu alloys with additions of chromium, zinc and scandium were studied. The microstructure of the spray formed alloys was analyzed by transmission electron microscopy. A range of tensile strengths were achieved, and varied based on elemental additions, and second phase particle strengthening. To explain the significantly higher strength in one alloy with scandium, theoretical results due to the yield stress of Al-Zn-Mg-Cu alloys as a function of volume fraction and precipitate particle size, were compared to experimental data. Both the possibilities of coherency and order strengthening are examined. The significant additional hardening achieved in the alloy with scandium is attributed to small ordered particles of Al 3 Sc, which precipitated during aging

  7. Potential for photocatalytic degradation of the potassic diclofenac using scandium and silver modified titanium dioxide thin films

    International Nuclear Information System (INIS)

    Ciola, R.A.; Oliveira, C.T.; Lopes, S.A.; Cavalheiro, A.A.

    2011-01-01

    The potential for photocatalytic degradation of the potassic diclofenac drug was investigated using titanium dioxide thin films modified with two modifier types, scandium and silver, both prepared by Sol-Gel method. It was demonstrated by UVVis spectroscopy analysis of the solutions containing the drug, under UV-A light irradiation that the degradation efficiency of the titanium dioxide photocatalyst is dependent of the semiconductor nature and that the scandium accelerates the first step of the degradation when compared to the silver. This result seems to be related to the redox potential of the electron-hole pair, once the scandium modifying sample generates a p type semiconductor that reduces the band gap. The extra holes attract more strongly the chorine ion present in diclofenac and leading to the releasing more easily. However, after the first byproducts degradation the following steps are not facilitated, making the silver modifying more advantageous. (author)

  8. Extraction of nitrates of lanthanoids (3) of the yttrium group and yttrium (3) by trialkylbenzylammonium nitrate in toluene

    International Nuclear Information System (INIS)

    Pyartman, A.K.; Kovalev, S.V.; Keskinov, V.A.; Kopyrin, A.A.

    1997-01-01

    A study was made on extraction of nitrates of lanthanoids (3) of the yttrium group (terbium-lutetium) and yttrium (3) by trialkylbensylammonium nitrate in toluene at T=298.15 K pH 2. Extraction isotherms are described with account of formation of compound of (R 4 N) 2 [Ln(NO 3 ) 5 ] composition in organic phase. Values of extraction constants decreasing in terbium (3)-lutetium (3) series, were calculated. Value of extraction constant for yttrium (3) is close to the value of extraction constant for ytterbium (3). 13 refs., 2 figs., 3 tabs

  9. Annual reports in inorganic and general syntheses 1974

    CERN Document Server

    Niedenzu, Kurt

    1975-01-01

    Annual Reports in Inorganic and General Syntheses-1974 presents an organized annual summary of synthetic developments in inorganic chemistry and its related areas. The book discusses the chemistry of simple and complex metal hydrides of main groups I, II, and III, boron, aluminium, gallium, indium, thallium, silicon, germanium, tin, lead, phosphorus, arsenic, antimony, bismuth, chalcogens, halogens, and pseudohalogens. The text also describes the chemistry of scandium, yttrium, lanthanides, actinides, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, ma

  10. Phosphors containing boron and metals of Group IIIA and IIIB

    Science.gov (United States)

    Setlur, Anant Achyut; Srivastava, Alok Mani; Comanzo, Holly Ann; Manivannan, Venkatesan

    2006-10-31

    A phosphor comprises: (a) at least a first metal selected from the group consisting of yttrium and elements of lanthanide series other than europium; (b) at least a second metal selected from the group consisting of aluminum, gallium, indium, and scandium; (c) boron; and (d) europium. The phosphor is used in light source that comprises a UV radiation source to convert UV radiation to visible light.

  11. Annual reports in inorganic and general syntheses 1972

    CERN Document Server

    Niedenzu, Kurt

    1973-01-01

    Annual Reports in Inorganic and General Syntheses-1972 presents an organized annual summary of synthetic developments in inorganic chemistry and its related areas. The book discusses alkali and alkaline earth elements, alloys, silver, gold, zinc, cadmium, mercury, boron, aluminum, gallium, indium, thallium, yttrium, scandium, lanthanides, actinides, titanium, zirconium, hafnium, Group V and VI transition elements, manganese, technetium, rhenium, iron, cobalt, nickel, ruthenium, osmium, rhodium, and iridium. The text also describes the chemistry of palladium, platinum, silicon, germanium, tin,

  12. Radiolabeling Of Albumin Particles With Yttrium-90

    International Nuclear Information System (INIS)

    Nguyen Thi Thu; Nguyen Thi Khanh Giang; Bui Van Cuong, Vo Thi Cam Hoa

    2011-01-01

    This paper presents the process of the radiolabeling of microaggregated albumin particles with radionuclide Yttrium-90 using the directed method. The albumin microsphere kit was prepared in sodium phosphate buffer. The original solution includes 2 mg albumin particle and 0.5 mg stannous chloride dihydrate. The albumin particles size was ranged from 5 ?m to 30 ?m. The mixture was washed three times with phosphate buffer saline, pH 7.2 by centrifugation and suspended in 0.5 M sodium acetate buffer, pH 6. Yttrium - 90 in 1.0 M acetic acid was collected from 90 Sr/ 90 Y generator. The labeling of the particles with Y-90 (185 MBq) was performed at pH 5.5 in acetate buffer with agitating for 60 min at room temperature. The labeled albumin suspensions were centrifuged at 3000 rpm for 15 min. Labeling yields was calculated using centrifugation, filtration and compared with paper chromatography, which is developed in the Tris Acetic EDTA. In this system, the unbound of Y-90 migrates to an R f of 0.9-1.0 and the radiolabeled albumin particles remains at the point of origin (R f = 0). The size of 90 Y-albumin particles was compared with the albumin particles in the original solution to be sure that they did not change during the labeling treatment. The radiolabeling yields were more than 80%. The labeled compound was dialysis in phosphate buffer. The radiochemical purity was 98%. The 90 Y- albumin is an ideal radiopharmaceutical for potential use in malignant cancer treatment as brachytherapy. (author)

  13. Etudes optiques de nouveaux materiaux laser: Des orthosilicates dopes a l'ytterbium: Le yttrium (lutetium,scandium) pentoxide de silicium

    Science.gov (United States)

    Denoyer, Aurelie

    La decouverte et l'elaboration de nouveaux materiaux laser solides suscitent beaucoup d'interet parmi la communaute scientifique. En particulier les lasers dans la gamme de frequence du micron debouchent sur beaucoup d'applications, en telecommunication, en medecine, dans le domaine militaire, pour la, decoupe des metaux (lasers de puissance), en optique non lineaire (doublage de frequence, bistabilite optique). Le plus couramment utilise actuellement est le Nd:YAG dans cette famille de laser, mais des remplacants plus performants sont toujours recherches. Les lasers a base d'Yb3+ possedent beaucoup d'avantages compares aux lasers Nd3+ du fait de leur structure electronique simple et de leur deterioration moins rapide. Parmi les matrices cristallines pouvant accueillir l'ytterbium, les orthosilicates Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5 se positionnent tres bien, du fait de leur bonne conductivite thermique et du fort eclatement de leur champ cristallin necessaire a l'elaboration de lasers quasi-3 niveaux. De plus l'etude fine et systematique des proprietes microscopiques de nouveaux materiaux s'avere toujours tres interessante du point de vue de la recherche fondamentale, c'est ainsi que de nouveaux modeles sont concus (par exemple pour le champ cristallin) ou que de nouvelles proprietes inhabituelles sont decouvertes, menant a de nouvelles applications. Ainsi d'autres materiaux dopes a l'ytterbium sont connus pour leurs proprietes de couplage electron-phonon, de couplage magnetique, d'emission cooperative ou encore de bistabilite optique, mais ces proprietes n'ont encore jamais ete mises en evidence dans Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5. Ainsi, cette these a pour but l'etude des proprietes optiques et des interactions microscopiques dans Yb:Y2SiO 5, Yb:Lu2SiO5 et Yb:Sc2SiO5. Nous utilisons principalement les techniques d'absorption IR et de spectroscopie Raman pour determiner les excitations du champ cristallin et les modes de vibration dans le materiau. Des mesures optiques sous champ magnetique ont egalement ete effectuees dans le but de caracteriser le comportement de ces excitations lorsqu'elles sont soumises a l'effet Zeeman. La resonance paramagnetique electronique a permis de completer cette etude de l'eclatement Zeeman suivant toutes les orientations du cristal. Enfin la fluorescence par excitation selective et la fluorescence induite par Raman FT, completent la description des niveaux d'energie et revelent l'existence d'emission cooperative de deux ions Yb3+ et de transferts d'energie. Les resultats de cette these apportent une contribution originale dans le domaine des nouveaux materiaux lasers par l'etude et la comprehension des interactions fines et des proprietes microscopiques d'un materiau en particulier. Ils debouchent a la fois sur des applications possibles dans le domaine de l'optique et des lasers, et sur la comprehension d'aspects fondamentaux. Cette these a prouve l'interet de ces matrices pour leur utilisation comme lasers solides: un fort eclatement du champ cristallin favorable a l'elaboration de laser quasi-3 niveaux, et de larges bandes d'absorption (dues a un fort couplage electron-phonon et a des raies satellites causees par une interaction d'echange entre deux ions Yb3+) qui permettent la generation d'impulsions laser ultra-courtes, l'accordabilite du laser, etc. De plus la miniaturisation des lasers est possible pour l'optique integree grace a des couches minces synthetisees par epitaxie en phase liquide dont nous avons demontre la tres bonne qualite structurale et l'ajustement possible de certains parametres. Nous avons reconstruit le tenseur g du niveau fondamental (qui donne des informations precieuses sur les fonctions d'onde), ceci dans le but d'aider les theoriciens a concevoir un modele de champ cristallin valide. Plusieurs mecanismes de transferts d'energie ont ete mis en evidence: un mecanisme de relaxation d'un site vers l'autre, un mecanisme d'emission cooperative, et un mecanisme d'excitation de l'Yb3+ par le Tm3+ (impurete presente dans le materiau). Ces transferts sont plutot nefastes pour la fabrication d'un laser mais sont interessants pour l'optique non lineaire (doublage de frequence, memoires optiques). Enfin, plusieurs elements (le couplage magnetique de paire, le couplage electron-phonon et l'emission cooperative) nous ont permis de conclure sur le caractere covalent de la matrice. Nous avons d'ailleurs demontre ici le role de la covalence dans l'emission cooperative, transition habituellement attribuee aux interactions multipolaires electriques.

  14. Comparative evaluation of surface topography of tooth prepared using erbium, chromium: Yttrium, scandium, gallium, garnet laser and bur and its clinical implications

    Directory of Open Access Journals (Sweden)

    Mahesh Verma

    2015-01-01

    Conclusions: Er, Cr: YSGG laser can be used for preparing tooth and bond strength value achieved by laser preparation alone without surface treatment procedure lies in the range of clinical acceptability.

  15. Effect of adhesive system application for cavities prepared with erbium, chromium: yttrium scandium gallium garnet laser on rat dental pulp tissue.

    Science.gov (United States)

    Takada, Mayo; Suzuki, Masaya; Haga-Tsujimura, Maiko; Shinkai, Koichi

    2017-07-01

    We examined the effects of adhesive systems under study applied for a laser-cut cavity using an Er,Cr:YSGG laser on rat dental pulp at 24 h and 14 days postoperatively. Group 1, laser-cut cavities were treated with a self-etching-primer and bonding agent; group 2, pretreated with a phosphoric-acid, and then treated with a self-etching-primer and bonding agent; group 3, pretreated with a phosphoric-acid and sodium-hypochlorite, and then treated with a self-etching-primer and bonding agent; and group 4, treated with an all-in-one adhesive. A flowable resin composite was used as filling material for each cavity treated with each group. A glass-ionomer-cement was used as a control. The following items were evaluated: pulp-tissue-disorganization (PTD), inflammatory-cell-infiltration (ICI), tertiary-dentin-formation (TDF), and bacterial-penetration (BP). The results were statistically analyzed using the Kruskal-Wallis test and Mann-Whitney U test. No significant differences were observed among the experimental groups for all parameters after 24 h and 14 days (P > 0.05). The majority of the specimens showed PTD with edema formation after 24 h; however, all the specimens demonstrated pulpal healing with TDF after 14 days. On the parameter of TDF, all groups showed significant differences between the two postoperative periods (P < 0.01). On the parameter of ICI, a significant difference was found between the two postoperative periods in group 4 (P < 0.05). No specimens showed BP. The pretreatment on the cavity prepared with the laser using phosphoric-acid or sodium-hypochlorite did not affect the dental pulp healing of rat tooth.

  16. Thermoanalytical study of the decomposition of yttrium trifluoroacetate thin films

    International Nuclear Information System (INIS)

    Eloussifi, H.; Farjas, J.; Roura, P.; Ricart, S.; Puig, T.; Obradors, X.; Dammak, M.

    2013-01-01

    We present the use of the thermal analysis techniques to study yttrium trifluoroacetate thin films decomposition. In situ analysis was done by means of thermogravimetry, differential thermal analysis, and evolved gas analysis. Solid residues at different stages and the final product have been characterized by X-ray diffraction and scanning electron microscopy. The thermal decomposition of yttrium trifluoroacetate thin films results in the formation of yttria and presents the same succession of intermediates than powder's decomposition, however, yttria and all intermediates but YF 3 appear at significantly lower temperatures. We also observe a dependence on the water partial pressure that was not observed in the decomposition of yttrium trifluoroacetate powders. Finally, a dependence on the substrate chemical composition is discerned. - Highlights: • Thermal decomposition of yttrium trifluoroacetate films. • Very different behavior of films with respect to powders. • Decomposition is enhanced in films. • Application of thermal analysis to chemical solution deposition synthesis of films

  17. Yttrium Nitrate mediated Nitration of Phenols at room temperature in ...

    Indian Academy of Sciences (India)

    The described method is selective for phenols. ... the significant cause of post translational modification that can ... decades, significant attention was paid on nitration of phenols to .... Progress of the reaction can be noted visually. Yttrium.

  18. The influence of the diluent nature on scandium extraction by the phenol-formaldehyde resol oligomer yarrezin B

    International Nuclear Information System (INIS)

    Semenov, S.A.; Valkina, E.M.; Reznik, A.M.

    1996-01-01

    The paper studies the effect of diluent nature on scandium extraction by Yarrezin B phenol-formaldehyde resol oligomer using n-octan, toluene, chloroform, n-octanol and kerosene as an example. Correlation coefficients of dependences of scandium distribution factor on some parameters of diluents are calculated. Possibility to use some parameters of diluents to predict their effect on extraction indices is determined. Hildebrandt solubility parameter of extracting agent and parameters of extracting agent-diluent interaction according to Flory-Haggins are calculated. 13 refs., 2 figs., 4 tabs

  19. Attempts at treating rheumatoid arthritis with radioactive yttrium

    International Nuclear Information System (INIS)

    Scott, J.T.

    1979-01-01

    Two years' observations on 33 knee joints in 33 patients with rheumatoid arthritis did not prove a therapeutic effect of Y 90 , which was tested in a randomized study against non-radioactive yttrium. It was noticable that 9 knee joints of the isotope group but only one of the control group became unstable. Independent of the yttrium treatment, significant improvement was noticed in patients where fibrin clots had been washed out of the joints in the course of arthroscopies. (orig.) [de

  20. Treatment of rheumatoid arthritis with 90yttrium. Follow up studies

    International Nuclear Information System (INIS)

    Teuber, J.; Baenkler, H.W.; Regler, G.; Erlangen-Nuernberg Univ., Erlangen

    1978-01-01

    90 Yttrium-silicate was injected into 131 knee-joints from patients with rheumatoid arthritis with stadium II-IV according to Steinbrocker. The observation period lasted until two years. After three months about 80% and after 24 months still more than 50% of the patients treated showed complete or partial remission. Side-effects as formerly observed with 198 -goldpreparations did not occur. Therefore the treatment with 90 Yttrium-silicate offers an alternative to surgical synovectomy. (orig.) [de

  1. Thermal decomposition of yttrium(III) propionate and butyrate

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude

    2013-01-01

    The thermal decompositions of yttrium(III) propionate monohydrate (Y(C2H5CO2)3·H2O) and yttrium(III) butyrate dihydrate (Y(C3H7CO2)3·2H2O) were studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction and hot-stage microscopy. These two...

  2. Activated phosphors having matrices of yttrium-transition metal compound

    International Nuclear Information System (INIS)

    De Kalb, E.L.; Fassel, V.A.

    1975-01-01

    A method is described for preparing a phosphor composition containing a lanthanide activator element with a host matrix having a transition element as a major component. The host matrix is composed of certain rare earth phosphates or vanadates such as YPO 4 with a portion of the rare earth replaced with one or more of the transition elements. On x-ray or other electromagnetic excitation, trace lanthanide impurities or additives within the phosphor are spectrometrically determined from their characteristic luminescence

  3. Lanthanide ions as spectral converters for solar cells

    NARCIS (Netherlands)

    van der Ende, B.M.; Aarts, L.; Meijerink, A.

    2009-01-01

    The use of lanthanide ions to convert photons to different, more useful, wavelengths is well-known from a wide range of applications (e.g. fluorescent tubes, lasers, white light LEDs). Recently, a new potential application has emerged: the use of lanthanide ions for spectral conversion in solar

  4. Luminescent lanthanide reporters: new concepts for use in bioanalytical applications

    International Nuclear Information System (INIS)

    Vuojola, Johanna; Soukka, Tero

    2014-01-01

    Lanthanides represent the chemical elements from lanthanum to lutetium. They intrinsically exhibit some very exciting photophysical properties, which can be further enhanced by incorporating the lanthanide ion into organic or inorganic sensitizing structures. A very popular approach is to conjugate the lanthanide ion to an organic chromophore structure forming lanthanide chelates. Another approach, which has quickly gained interest, is to incorporate the lanthanide ions into nanoparticle structures, thus attaining improved specific activity and a large surface area for biomolecule immobilization. Lanthanide-based reporters, when properly shielded from the quenching effects of water, usually express strong luminescence emission, multiple narrow emission lines covering a wide wavelength range, and exceptionally long excited state lifetimes enabling time-gated luminescence detection. Because of these properties, lanthanide-based reporters have found widespread applications in various fields of life. This review focuses on the field of bioanalytical applications. Luminescent lanthanide reporters and assay formats utilizing these reporters pave the way for increasingly sensitive, simple, and easily automated bioanalytical applications. (topical review)

  5. Determination of aluminium, scandium and rare earth elements by emission flame spectrometry

    International Nuclear Information System (INIS)

    Otruba, V.; Sommer, L.

    1989-01-01

    Emission spectrometry in nitrous oxide-acetylene flames in combination with a highly resolving double monochromator and sensitive detecting system enables simple, sensitive and selective determinations of aluminium, scandium and all rare earth elements with exception of cerium in complicated matrices. Calibration plots are linear for a large concentration interval (≤ 100 μgxml -1 ), detection limits are in ngxml -1 level and RSD does not exceed 3% on the optimal concentration level of the particular element. The determination of Al, Sc, Eu and Yb showed particular advantages as to methods using ICP-spectrometry. (orig.)

  6. 3He release characteristics of metal tritides and scandium--tritium solid solutions

    International Nuclear Information System (INIS)

    Perkins, W.G.; Kass, W.J.; Beavis, L.C.

    1975-01-01

    Tritides of such metals as scandium, titanium, and erbium are useful materials for determining the effects of helium accumulation in metallic solids, for example, CTR first wall materials. Such effects include lattice strain and gross deformation, as reported elsewhere, which are related to 3 He retention and ultimate release. Long term gas release studies have indicated that, during the early life of a metal ditritide, a large fraction of the 3 He is retained in the solid. At more advanced ages (2 to 4 years, depending on the parent metal), the 3 He release rate becomes comparable to the generation rate. Statistical analysis of the data indicates that the acceleration in 3 He release rate depends on accumulated 3 He concentration rather than strictly on age. 3 He outgassing results are presented for thin films of ScT 2 , TiT 2 , and ErT 2 , and the critical 3 He concentrations are discussed in terms of a percolation model. Phase transformations which occur on tritide formation cast some doubt on the validity of extrapolating results obtained for metal tritides to predictions regarding the accumulation of helium in metals. Scandium is unique among the early transition and rare-earth metals in that the metal exhibits a very high room temperature tritium solubility (T/Sc = 0.4) with no phase transformation. Indeed, even the lattice parameters of the hcp scandium lattice are only minimally changed by tritium solution, and we have succeeded in obtaining single crystal ScT 0 . 3 samples in two crystallographic orientations. Using a very sensitive technique, we have measured 3 He emission from both these samples, as well as from fine-grained thin film scandium-tritium solid solution samples (ScT 0 . 3 - 0 . 4 ). The fine-grained film samples release 3 He at 2 to 3 percent of the generation rate, while the emission rate from the single-crystal samples is approximately 0.05 percent of the generation rate, indicating a strong grain size effect

  7. Scandium-doped zinc cadmium oxide as a new stable n-type oxide thermoelectric material

    DEFF Research Database (Denmark)

    Han, Li; Christensen, Dennis Valbjørn; Bhowmik, Arghya

    2016-01-01

    Scandium-doped zinc cadmium oxide (Sc-doped ZnCdO) is proposed as a new n-type oxide thermoelectric material. The material is sintered in air to maintain the oxygen stoichiometry and avoid instability issues. The successful alloying of CdO with ZnO at a molar ratio of 1 : 9 significantly reduced...... is a good candidate for improving the overall conversion efficiencies in oxide thermoelectric modules. Meanwhile, Sc-doped ZnCdO is robust in air at high temperatures, whereas other n-type materials, such as Al-doped ZnO, will experience rapid degradation of their electrical conductivity and ZT....

  8. Scandium sorption by immobilized microdispersed forms of phosporus-containing ion exchangers

    International Nuclear Information System (INIS)

    Sokolova, Yu.V.; Kurdyumov, G.M.; Smirnov, A.V.; Mezhirov, M.S.

    1991-01-01

    The possibility to improve considerably kinetics of scandium sorption by phosphate ion exchangers, immobilized into polyacrylonitrile (PAN) fibers, as compared with granular samples of ion exchangers, was shown. The influence of dispersion degree of immobilized ionite particles on sorption rate was studied. It is ascertained that the ionite grinding to the particle size ≤ 52 μm is sufficient for the rate increase by 1-1.5 orders. A lower swelling of the immobilized ion exchanger is its additional advantage as compared with granular form

  9. Separation and estimation of lanthanides using high performance liquid chromatography

    International Nuclear Information System (INIS)

    Datta, Arpita; Sivaraman, N.; Vasudeva Rao, P.R.

    2012-01-01

    The separation efficiency of individual lanthanides depends on the stability constant of the metal-ligand complex. Therefore, stability constant data of lanthanide complexes is important in the development of high performance separation procedures. The dynamic ion exchange HPLC technique was employed at our laboratory to estimate the stability constant of lanthanides with various complexing agents. In these studies, the retention times as well as capacity factors of lanthanides and some actinides were measured as a function of CSA, complexing agent concentrations and mobile phase pH. From these studies, a correlation has been established between capacity factor of a metal ion, concentrations of ion-pairing reagent and complexing agent with the stability constant of lanthanide complex

  10. Experimental solubility measurements of lanthanides in liquid alkalis

    Science.gov (United States)

    Isler, Jeremy; Zhang, Jinsuo; Mariani, Robert; Unal, Cetin

    2017-11-01

    In metallic nuclear fuel, lanthanide fission products play a crucial role in the fuel burnup-limiting phenomena of fuel cladding-chemical interaction (FCCI). The lanthanides have been hypothesized to transport by a 'liquid-like' mechanism out of the metallic fuel to the fuel peripheral to cause FCCI. By liquid fission product cesium and liquid bond sodium, the lanthanides are transported to the peripheral of the fuel through the porosity of the fuel. This work investigates the interaction between the lanthanides and the alkali metals by experimentally measuring the solubility of lanthanides within liquid sodium, and neodymium in liquid cesium and mixtures of cesium and sodium. The temperature dependence of the solubility is experimentally determined within an inert environment. In addition, the dependence of the solubility on the alkali metal concentration in liquid mixtures of cesium and sodium was examined. In quantifying the solubility, the fundamental understanding of this transport mechanism can be better determined.

  11. Lanthanide contraction effect on crystal structures of lanthanide coordination polymers with cyclohexanocucurbit[6]uril ligand

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Li-Mei [College of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001 (China); Liu, Jing-Xin, E-mail: jxliu411@ahut.edu.cn [College of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (China)

    2017-01-15

    A series of compounds based on the macrocyclic ligand cyclohexanocucurbit[6]uril (Cy6Q[6]) with formulas (Ln(H{sub 2}O){sub 6}Cy6Q[6])·2(CdCl{sub 4})·H{sub 3}O·xH{sub 2}O [isomorphous with Ln=La (1), Ce (2), Pr (3) and Nd (4), x=11 (1), 11 (2), 10 (3) and 11 (4)], (Sm(H{sub 2}O){sub 5}Cy6Q[6])·2(CdCl{sub 4})·H{sub 3}O·10H{sub 2}O (5) and (Ln(H{sub 2}O){sub 5}(NO{sub 3})@Cy6Q[6])·2(CdCl{sub 4})·2H{sub 3}O·xH{sub 2}O [isomorphous with Ln=Gd (6), Tb (7) and Dy (8), x=8 (6), 6 (7) and 6 (8)], have been successfully synthesized by the self-assembly of Cy6Q[6] with the corresponding lanthanide nitrate under hydrochloric acid aqueous solution in the presence of CdCl{sub 2}. Single-crystal X-ray diffraction analyses revealed that compounds 1–8 all crystallize in monoclinic space group P2{sub 1}/c, and display 1D coordination polymer structures. The lanthanide contraction effect on the structures of 1–8 has also been investigated and discussed in detail. In contrast, the reaction of Cy6Q[6] with the Ho(NO){sub 3}, Tm(NO){sub 3}, Yb(NO){sub 3} under the same conditions resulted in the compounds 9–11 with formulas Cy6Q[6]·2(CdCl{sub 4})·2H{sub 3}O·xH{sub 2}O [isomorphous with x=10 (9), 10 (10), and 9 (11)], in which no lanthanide cations are observed. The structural difference of these compounds indicates that the Cy6Q[6] may be used in the separation of lanthanide cations. - Graphical abstract: The reaction of cyclohexanocucurbit[6]uril with lanthanide ions (La{sup 3+}, Ce{sup 3+}, Pr{sup 3+}, Nd{sup 3+}, Sm{sup 3+}, Gd{sup 3+}, Tb{sup 3+}, Dy{sup 3+}, Ho{sup 3+}, Tm{sup 3+} and Yb{sup 3+}) under hydrochloric acid in the presence of CdCl{sub 2} resulted in eleven compounds, which demonstrate interesting lanthanide contraction effect and provide a means of separating lanthanide ions. - Highlights: • Eleven compounds of the Ln{sup 3+} with the Cy6Q[6] were synthesized and described. • Compounds 1-8 demonstrate interesting lanthanide contraction effect.

  12. Separation device of radio lanthanides (DISER)

    International Nuclear Information System (INIS)

    Vera T, A.L.; Monroy G, F.; Vazquez M, J.C.; Jimenez B, F.

    2008-01-01

    At the present time the cancer is one of the main causes of mortality in our country, therefore, its prevention, diagnostic and treatment is of vital importance for those health systems. The treatment of the cancer and other illnesses, starting from monoclonal antibodies, peptides, macro aggregates or marked aminoacids with beta particles emitting radioisotopes, it is an extremely promising field. The radioactive lanthanides: Promethium 149, Terbium 161, Holmium 166 and Lutetium 177 are beta emitting (β), which possess nuclear and chemical properties that have shown their feasibility like radioisotopes of radiotherapeutic use. However, these radioisotopes are not commercially available; to this respect, the Radioactive Materials Research Laboratory (LIMR) of the National Institute of Nuclear Research (ININ), it has developed the methodology of production of these radioisotopes and based on these works, there is designed, built and mounted the Radio lanthanides Separation Device (DISER) able to carry out the radioisotopes production in a routine way. This device is content in a cell that has an auxiliary air service, an extraction system and it is protected with a lead armor-plating of 10 cm. The DISER it is manual and easy of managing. The main function of this equipment is the radio lanthanides separation starting from the extractive chromatography by means of packed columns with a commercial resin (LnSPS) and recovered in the superior and inferior part by fiber glass. The DISER is composed by a main carrousel where the separation columns and the elution recipients are mounted. Also counts with an opening system of irradiation vials, port samples for columns and glass material. The present work presents a detailed description of the DISER, as well as its handling that allows to produce the radioisotopes Promethium-149, Terbium-161, Holmium-166 and Lutetium-177 starting from the separation of its parent elements Neodymium-149, Gadolinium-161, Dysprosium-166 and

  13. Thermodynamic study on the complexation of Trivalent actinide and lanthanide cation by N-donor ligands in homogeneous conditions; Etude thermodynamique de la complexation des ions actinide (III) et lanthanide (III) par des ligands polyazotes en milieu homogene

    Energy Technology Data Exchange (ETDEWEB)

    Miguirditchian, M

    2004-07-01

    Polydentate N-donor ligands, alone or combined with a synergic acid, may selectively extract minor actinides(III) from lanthanide(III) ions, allowing to develop separation processes of long-live radioelements. The aim of the researches carried out during this thesis was to better understand the chemical mechanisms of the complexation of f-elements by Adptz, a tridentate N-donor ligand, in homogeneous conditions. A thermodynamic approach was retained in order to estimate, from an energetic point of view, the influence of the different contributions to the reaction, and to acquire a complete set of thermodynamic data on this reaction. First, the influence of the nature of the cation on the thermodynamics was considered. The stability constants of the 1/1 complexes were systematically determined by UV-visible spectrophotometry for every lanthanide ion (except promethium) and for yttrium in a mixed solvent methanol/water in volume proportions 75/25%. The thermodynamic parameters ({delta}H{sup 0} {delta}{sup S}) of complexation were estimated by the van't Hoff method and by micro-calorimetry. The trends of the variations across the lanthanide series are compared with similar studies. The same methods were applied to the study of three actinide(III) cations: plutonium, americium and curium. The comparison of these values with those obtained for the lanthanides highlights the increase of stability of these complexes by a factor of 20 in favor of the actinide cations. This gap is explained by a more exothermic reaction and is associated, in the data interpretation, to a higher covalency of the actinide(III)-nitrogen bond. Then, the influence of the change of solvent composition on the thermodynamic of complexation was studied. The thermodynamic parameters of the complexation of europium(III) by Adptz were determined for several fractions of methanol. The stability of the complex formed increases with the percentage of methanol in the mixed solvent, owing to an

  14. Calmodulin-lanthanide ion exchange kinetics

    International Nuclear Information System (INIS)

    Buccigross, J.; O'Donnell, C.; Nelson, D.

    1985-01-01

    A flow dialysis apparatus suitable for the study of high affinity metal binding proteins has been utilized to study calmodulin-metal exchange kinetics. Calmodulin labeled with Eu-155 and Gd-153 was dialyzed against buffer containing various competing metal ions. The rate of metal exchange was monitored by a gamma-ray scintillation detector. The kinetics of exchange are first order, and the rates fall into two categories: Ca (II) and CD (II) in one, and the lanthanides Eu (III), Gd (III), and La (III) in the other

  15. Thermal decomposition of lanthanide and actinide tetrafluorides

    International Nuclear Information System (INIS)

    Gibson, J.K.; Haire, R.G.

    1988-01-01

    The thermal stabilities of several lanthanide/actinide tetrafluorides have been studied using mass spectrometry to monitor the gaseous decomposition products, and powder X-ray diffraction (XRD) to identify solid products. The tetrafluorides, TbF 4 , CmF 4 , and AmF 4 , have been found to thermally decompose to their respective solid trifluorides with accompanying release of fluorine, while cerium tetrafluoride has been found to be significantly more thermally stable and to congruently sublime as CeF 4 prior to appreciable decomposition. The results of these studies are discussed in relation to other relevant experimental studies and the thermodynamics of the decomposition processes. 9 refs., 3 figs

  16. Analysis and separation of lanthanide elements

    International Nuclear Information System (INIS)

    Almeida Pimentel, E. de.

    1973-01-01

    Improvements of rare earth separation by the combined use of acetic and critic acid were studied and analytical methods for determining some of the lanthanides were tryed out. Separations of the R.E. studied were favorable when citric acid (solution A) and acetic acid (solution B) were used in the proportion of 10:1 at pH=4,00. Neutron activation, spectro-photometric, polarographic, volumetric and gravimetric procedures allowed the determination of 8 R.E.; samarium, neodymium, praseodymium, lanthanum, cerium, holmium, erbium and europium

  17. Structure and Magnetic Properties of Lanthanide Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, James Henry [Vanderbilt Univ., Nashville, TN (United States)

    2014-06-01

    We have had considerable success on this project, particularly in the understanding of the relationship between nanostructure and magnetic properties in lanthanide nanocrystals. We also have successfully facilitated the doctoral degrees of Dr. Suseela Somarajan, in the Department of Physics and Astronomy, and Dr. Melissa Harrison, in the Materials Science Program. The following passages summarize the various accomplishments that were featured in 9 publications that were generated based on support from this grant. We thank the Department of Energy for their generous support of our research efforts in this area of materials science, magnetism, and electron microscopy.

  18. Spectral studies of Lanthanide interactions with membrane surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Karukstis, K.K.; Kao, M.Y.; Savin, D.A.; Bittker, R.A.; Kaphengst, K.J.; Emetarom, C.M.; Naito, N.R.; Takamoto, D.Y. [Harvey Mudd College, Claremont, CA (United States)

    1995-03-23

    We have monitored the interactions of the series of trivalent lanthanide cations with the thylakoid membrane surface of spinach chloroplasts using two complementary spectral techniques. Measurements of the fluorescence emission of the extrinsic probe 2-p-toluidinonaphthalene-6-sulfonate (TNS) and the absorbance of the intrinsic chromophore chlorophyll provide two sensitive means of characterizing the dependence of the cation-membrane interaction on the nature of the cation. In these systems, added lanthanide cations adsorb onto the membrane surface to neutralize exposed segments of membrane-embedded protein complexes. The lanthanide-induced charge neutralization increases the proximity of added TNS anion to the membrane surface as evidenced by variations in the TNS fluorescence level and wavelength of maximum emission. Our results reveal a strong dependence of TNS fluorescence parameters on both lanthanide size and total orbital angular momentum L value. Lanthanides with greater charge density (small size and/or low L value) enhance the TNS fluorescence level to a greater extent. A possible origin for the lanthanide-dependent TNS fluorescence levels is suggested in terms of a heterogeneity in the number and type of TNS binding sites. The data are consistent with the proposal that larger lanthanides with smaller enthalpies of hydration induce more significant membrane appression. 59 refs., 9 figs., 2 tabs.

  19. Mechanical properties of lanthanum and yttrium chromites

    Energy Technology Data Exchange (ETDEWEB)

    Paulik, S.W.; Armstrong, T.R. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-12-31

    In an operating high-temperature (1000{degrees}C) solid oxide fuel cell (SOFC), the interconnect separates the fuel (P(O{sub 2}){approx}10{sup -16} atm) and the oxidant (P(O2){approx}10{sup 0.2} atm), while being electrically conductive and connecting the cells in series. Such severe atmospheric and thermal demands greatly reduce the number of viable candidate materials. Only two materials, acceptor substituted lanthanum chromite and yttrium chromite, meet these severe requirements. In acceptor substituted chromites (Sr{sup 2+} or Ca{sup 2+} for La{sup 3+}), charge compensation is primarily electronic in oxidizing conditions (through the formation of Cr{sup 4+}). Under reducing conditions, ionic charge compensation becomes significant as the lattice becomes oxygen deficient. The formation of oxygen vacancies is accompanied by the reduction of Cr{sup 4+} ions to Cr{sup 3+} and a resultant lattice expansion. The lattice expansion observed in large chemical potential gradients is not desirable and has been found to result in greatly reduced mechanical strength.

  20. Tungsten - Yttrium Based Nuclear Structural Materials

    Science.gov (United States)

    Ramana, Chintalapalle; Chessa, Jack; Martinenz, Gustavo

    2013-04-01

    The challenging problem currently facing the nuclear science community in this 21st century is design and development of novel structural materials, which will have an impact on the next-generation nuclear reactors. The materials available at present include reduced activation ferritic/martensitic steels, dispersion strengthened reduced activation ferritic steels, and vanadium- or tungsten-based alloys. These materials exhibit one or more specific problems, which are either intrinsic or caused by reactors. This work is focussed towards tungsten-yttrium (W-Y) based alloys and oxide ceramics, which can be utilized in nuclear applications. The goal is to derive a fundamental scientific understanding of W-Y-based materials. In collaboration with University of Califonia -- Davis, the project is designated to demonstrate the W-Y based alloys, ceramics and composites with enhanced physical, mechanical, thermo-chemical properties and higher radiation resistance. Efforts are focussed on understanding the microstructure, manipulating materials behavior under charged-particle and neutron irradiation, and create a knowledge database of defects, elemental diffusion/segregation, and defect trapping along grain boundaries and interfaces. Preliminary results will be discussed.

  1. Neutron scattering study of yttrium iron garnet

    Science.gov (United States)

    Shamoto, Shin-ichi; Ito, Takashi U.; Onishi, Hiroaki; Yamauchi, Hiroki; Inamura, Yasuhiro; Matsuura, Masato; Akatsu, Mitsuhiro; Kodama, Katsuaki; Nakao, Akiko; Moyoshi, Taketo; Munakata, Koji; Ohhara, Takashi; Nakamura, Mitsutaka; Ohira-Kawamura, Seiko; Nemoto, Yuichi; Shibata, Kaoru

    2018-02-01

    The nuclear and magnetic structure and full magnon dispersions of yttrium iron garnet Y3Fe5O12 have been studied using neutron scattering. The refined nuclear structure is distorted to a trigonal space group of R 3 ¯ . The highest-energy dispersion extends up to 86 meV. The observed dispersions are reproduced by a simple model with three nearest-neighbor-exchange integrals between 16 a (octahedral) and 24 d (tetrahedral) sites, Ja a, Ja d, and Jd d, which are estimated to be 0.00 ±0.05 , -2.90 ±0.07 , and -0.35 ±0.08 meV, respectively. The lowest-energy dispersion below 14 meV exhibits a quadratic dispersion as expected from ferromagnetic magnons. The imaginary part of q -integrated dynamical spin susceptibility χ″(E ) exhibits a square-root energy dependence at low energies. The magnon density of state is estimated from χ″(E ) obtained on an absolute scale. The value is consistent with the single chirality mode for the magnon branch expected theoretically.

  2. Studies on yttrium-containing smart alloys

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Felix; Wegener, Tobias; Litnovsky, Andrey; Rasinski, Marcin; Linsmeier, Christian [Forschungszentrum Juelich GmbH, Institut fuer Energie- und Klimaforschung - Plasmaphysik (Germany); Mayer, Joachim [Ernst Ruska-Centrum, 52425 Juelich (Germany)

    2016-07-01

    Tungsten is the main candidate as plasma-facing armour material for future fusion reactors, like DEMO. Advantages of tungsten include high melting point, high thermal conductivity, low tritium retention, and low erosion yield. A problem is oxide volatilisation under accidental conditions where the temperature of the first wall can reach 1200 K to 1450 K and air ingress occurs. Therefore smart tungsten alloys are developed. Smart alloys are supposed to preserve properties of tungsten during plasma operation coupled with suppressed tungsten oxide formation in case of an accident. Lab-scale tungsten-chromium-yttrium (W-Cr-Y) samples prepared by magnetron sputtering are used as model system. The mechanisms of oxidation and its dynamics are studied using a thermogravimetric system, focussed ion beam, and electron microscopy. A composition scan was conducted: The new material composition featuring W, ∝ 12 wt.% Cr, ∝ 0.3 wt.% Y showed strongest suppression of oxidation, no pores, and least internal oxidation. At 1273 K in argon-oxygen atmosphere an oxidation rate of 3 . 10{sup -6} mg{sup 2}cm{sup -4}s{sup -1} was measured. At 1473 K ternary W-Cr-Y alloys suppressed evaporation up to 20 min while for W-Cr evaporation was already evident after 5 min. Comparison of passivation in dry and humid atmosphere, at temperatures of 1073 K to 1473 K is performed.

  3. Yttrium-90 microsphere induced gastrointestinal tract ulceration

    Directory of Open Access Journals (Sweden)

    Rikabi Ali A

    2008-09-01

    Full Text Available Abstract Background Radiomicrosphere therapy (RT utilizing yttrium-90 (90Y microspheres has been shown to be an effective regional treatment for primary and secondary hepatic malignancies. We sought to determine a large academic institution's experience regarding the extent and frequency of gastrointestinal complications. Methods Between 2004 and 2007, 27 patients underwent RT for primary or secondary hepatic malignancies. Charts were subsequently reviewed to determine the incidence and severity of GI ulceration. Results Three patients presented with gastrointestinal bleeding and underwent upper endoscopy. Review of the pretreatment angiograms showed normal vascular anatomy in one patient, sclerosed hepatic vasculature in a patient who had undergone prior chemoembolization in a second, and an aberrant left hepatic artery in a third. None had undergone prophylactic gastroduodenal artery embolization. Endoscopic findings included erythema, mucosal erosions, and large gastric ulcers. Microspheres were visible on endoscopic biopsy. In two patients, gastric ulcers were persistent at the time of repeat endoscopy 1–4 months later despite proton pump inhibitor therapy. One elderly patient who refused surgical intervention died from recurrent hemorrhage. Conclusion Gastrointestinal ulceration is a known yet rarely reported complication of 90Y microsphere embolization with potentially life-threatening consequences. Once diagnosed, refractory ulcers should be considered for aggressive surgical management.

  4. Lanthanide light for biology and medical diagnosis

    International Nuclear Information System (INIS)

    Bünzli, Jean-Claude G.

    2016-01-01

    Optical imaging emerges as a vital component of the various techniques needed to meet the stringent requirements of modern bioanalysis and bioimaging. Lanthanide luminescent bioprobes (LLBs) have greatly contributed to this field during the past 35 years because they have definite advantages such as little or no photobleaching and, thanks to time-gated detection, high sensitivity. The review summarizes the numerous tools offered by LLBs under their various forms, coordination compounds, nanoparticles, upconverting nanoparticles and their bioconjugates. It then focuses on biosensing, including point-of-care analysis, and then on both in vitro and in vivo bioimaging with visible and NIR light. The last section compares the performances of LLBs versus those of other commonly used bioprobes (organic dyes, quantum dots, and transition metal complexes). It is concluded that although LLBs will not replace all of existing bioprobes, they add invaluable new specific technologies to the biologist and medical doctor toolboxes. A good deal of improvements are achieved through nanotechnologies, which demonstrates that progresses in biosciences depend on the intersection of different disciplines, photophysics, chemistry, biochemistry, nanotechnology, and materials science. - Highlights: • Lanthanide luminescent bioprobes (LLBs) are indispensable tools in biosciences. • The tools provided by LLBs are summarized. • Main trends in biosensing and point-of-care analysis are presented. • Issues regarding optical bioimaging with visible and NIR light are described. • Characteristics of LLBs, including nanoparticles, are compared to other bioprobes.

  5. Lanthanide light for biology and medical diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Bünzli, Jean-Claude G., E-mail: jean-claude.bunzli@epfl.ch [Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002 (China); Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland)

    2016-02-15

    Optical imaging emerges as a vital component of the various techniques needed to meet the stringent requirements of modern bioanalysis and bioimaging. Lanthanide luminescent bioprobes (LLBs) have greatly contributed to this field during the past 35 years because they have definite advantages such as little or no photobleaching and, thanks to time-gated detection, high sensitivity. The review summarizes the numerous tools offered by LLBs under their various forms, coordination compounds, nanoparticles, upconverting nanoparticles and their bioconjugates. It then focuses on biosensing, including point-of-care analysis, and then on both in vitro and in vivo bioimaging with visible and NIR light. The last section compares the performances of LLBs versus those of other commonly used bioprobes (organic dyes, quantum dots, and transition metal complexes). It is concluded that although LLBs will not replace all of existing bioprobes, they add invaluable new specific technologies to the biologist and medical doctor toolboxes. A good deal of improvements are achieved through nanotechnologies, which demonstrates that progresses in biosciences depend on the intersection of different disciplines, photophysics, chemistry, biochemistry, nanotechnology, and materials science. - Highlights: • Lanthanide luminescent bioprobes (LLBs) are indispensable tools in biosciences. • The tools provided by LLBs are summarized. • Main trends in biosensing and point-of-care analysis are presented. • Issues regarding optical bioimaging with visible and NIR light are described. • Characteristics of LLBs, including nanoparticles, are compared to other bioprobes.

  6. Hyperpolarized 89Y NMR spectroscopic detection of yttrium ion and DOTA macrocyclic ligand complexation: pH dependence and Y-DOTA intermediates

    Science.gov (United States)

    Ferguson, Sarah; Kiswandhi, Andhika; Niedbalski, Peter; Parish, Christopher; Kovacs, Zoltan; Lumata, Lloyd

    Dissolution dynamic nuclear polarization (DNP) is a rapidly emerging physics technique used to enhance the signal strength in nuclear magnetic resonance (NMR) and imaging (MRI) experiments for nuclear spins such as yttrium-89 by >10,000-fold. One of the most common and stable MRI contrast agents used in the clinic is Gd-DOTA. In this work, we have investigated the binding of the yttrium and DOTA ligand as a model for complexation of Gd ion and DOTA ligand. The macrocyclic ligand DOTA is special because its complexation with lanthanide ions such as Gd3+ or Y3+ is highly pH dependent. Using this physics technology, we have tracked the complexation kinetics of hyperpolarized Y-triflate and DOTA ligand in real-time and detected the Y-DOTA intermediates. Different kinds of buffers were used (lactate, acetate, citrate, oxalate) and the pseudo-first order complexation kinetic calculations will be discussed. The authors would like to acknowledge the support by US Dept of Defense Award No. W81XWH-14-1-0048 and Robert A. Welch Foundation Grant No. AT-1877.

  7. Diphenyl-phosphinyl-morpholide (DPPM) lanthanide trifluoroacetate adducts

    International Nuclear Information System (INIS)

    Carvalho, L.R.F. de; Kim, D.J.

    1984-01-01

    Preparation and properties of adducts of lanthanide salts and diphenyl-phosphinyl-morpholide (DPPM) have been described in the literature. Addition compounds containing lanthanide nitrates, isothiocyanates, perchlorates, chlorides, bromides with DPPM have been obtained. In this article, the preparation and characterization of the addition compounds of lanthanide trifluoroacetates (TFA) with DPPM are reported. The compounds of general formula Ln (TFA) 3 . 3DPPM, Ln= La-Lu, Y were characterized by elemental analysis, melting ranges, infrared spectra, absorption and emission visible spectra, X-ray powder patterns. (Author) [pt

  8. Lanthanide-doped upconverting phosphors for bioassay and therapy

    Science.gov (United States)

    Guo, Huichen; Sun, Shiqi

    2012-10-01

    Lanthanide-doped fluorescent materials have gained increasing attention in recent years due to their unique luminescence properties which have led to their use in wide-ranging fields including those of biological applications. Aside from being used as agents for in vivo imaging, lanthanide-doped fluorescent materials also present many advantages for use in bioassays and therapy. In this review, we summarize the applications of lanthanide-doped up-converting phosphors (UCPs) in protein and gene detection, as well as in photodynamic and gene therapy in recent years, and outline their future potential in biological applications. The current report could serve as a reference for researchers in relevant fields.

  9. Lanthanide (III) complexes of 2-(N-salicylideneamino)-4-phenylthiazole

    International Nuclear Information System (INIS)

    Sasidharan, G.N.; Mohanan, K.; Lakshmi Prabha, A.N.

    2002-01-01

    Lanthanide(III) complexes of 2-(N-salicylideneamino)-4- phenylthiazole (HSAT) have been synthesised and characterised by elemental, analytical, thermogravimetric, molar conductance, UV- visible, IR and NMR spectral data. The ligand coordinates to the lanthanide(III) ion in a tridentate fashion without deprotonation, giving complexes of the type [Ln(HSAT) 2 (NO 3 ) 3 ] and [Ln(HSAT) 2 (H 2 0) 3 Cl 3 ]. The spectral data reveal that the ligand is bonded to the lanthanide ion through azomethine nitrogen, ring nitrogen and phenolic oxygen without deprotonation. The nitrate group acts in a bidentate fashion. The ligand and the metal complexes exhibit antibacterial and antifungal activities. (author)

  10. Yttrium implantation effects on extra low carbon steel and pure iron

    Energy Technology Data Exchange (ETDEWEB)

    Caudron, E.; Buscail, H. [Clermont-Ferrand-2 Univ., Le Puy en Velay (France). Lab. Vellave d`Elaboration; Jacob, Y.P.; Stroosnijder, M.F. [Institute for Advanced Materials, Joint Research Center, The European Commission, 21020, Ispra (Vatican City State, Holy See) (Italy); Josse-Courty, C. [Laboratoire de Recherche sur la Reactivite des Solides, UMR 56-13 CNRS, UFR Sciences et Techniques, 9 Avenue A. Savary, B.P. 400, 21011, Dijon Cedex (France)

    1999-05-25

    Extra low carbon steel and pure electrolytic iron samples were yttrium implanted using ion implantation technique. Compositions and structures of pure iron and steel samples were investigated before and after yttrium implantation by several analytical and structural techniques (RBS, SIMS, RHEED and XRD) to observe the yttrium implantation depth profiles in the samples. This paper shows the different effects of yttrium implantations (compositions and structures) according to the implanted sample nature. (orig.) 23 refs.

  11. Studies on yttrium oxide coatings for corrosion protection against molten uranium

    International Nuclear Information System (INIS)

    Chakravarthy, Y.; Bhandari, Subhankar; Pragatheeswaran; Thiyagarajan, T.K.; Ananthapadmanabhan, P.V.; Das, A.K.; Kumar, Jay; Kutty, T.R.G.

    2012-01-01

    Yttrium oxide is resistant to corrosion by molten uranium and its alloys. Yttrium oxide is recommended as a protective oxide layer on graphite and metal components used for melting and processing uranium and its alloys. This paper presents studies on the efficacy of plasma sprayed yttrium oxide coatings for barrier applications against molten uranium

  12. Fragment molecular orbital method for studying lanthanide interactions with proteins

    Energy Technology Data Exchange (ETDEWEB)

    Tsushima, Satoru [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biophysics; Komeiji, Y. [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Mochizuki, Y. [Rikkyo Univ., Tokyo (Japan)

    2017-06-01

    The binding affinity of the calcium-binding protein calmodulin towards Eu{sup 3+} was studied as a model for lanthanide protein interactions in the large family of ''EF-hand'' calcium-binding proteins.

  13. Recovery of uranium and the lanthanides from phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Habashi, F; Awadalla, F T; Zailaf, M

    1986-06-01

    A process is proposed for the treatment of phosphate rock for the recovery of uranium and lanthanides. The process assures the production of phosphatic fertilisers without polluting the environment with radioactive material.

  14. Lanthanide-doped luminescent nanomaterials from fundamentals to bioapplications

    CERN Document Server

    Chen, Xueyuan; Tu, Datao

    2014-01-01

    Lanthanide-Doped Luminescent Nanomaterials reviews the latest advances in the development of lanthanide-doped luminescent inorganic nanoparticles for potential bioapplications. This book covers the chemical and physical fundamentals of these nanoparticles, such as the controlled synthesis methodology, surface modification chemistry, optical physics, and their promising applications in diverse bioassays, with an emphasis on heterogeneous and homogeneous in-vitro biodetection of tumor biomarkers. This book is intended for those readers who are interested in systematically understanding the materials design strategy, optical behavior of lanthanide ions, and practical bioapplications of lanthanide nanoparticles. It primarily focuses on the interdisciplinary frontiers in chemistry, physics and biological aspects of luminescent nanomaterials. All chapters were written by scientists active in this field and for a broad audience, providing both beginners and advanced researchers with comprehensive information on the ...

  15. Pressure of saturated vapor of yttrium and zirconium acetylacetonates

    Energy Technology Data Exchange (ETDEWEB)

    Trembovetskij, G.V.; Berdonosov, S.S.; Murav' eva, I.A.; Martynenko, L.I. (Moskovskij Gosudarstvennyj Univ. (USSR))

    1984-08-01

    The static method and the flow method using /sup 91/Y and /sup 95/Zr radioactive indicators have been applied to determine pressure of saturated vapour of yttrium and zirconium acetylacetonates. Values of thermodynamic functions ..delta..Hsub(subl)=(98+-16)kJ/mol and ..delta..Ssub(subl.)=(155+-30)J/mol x K are calculated for sublimation of yttrium acetylacetonate. For sublimation of zirconium acetylacetonates ..delta..Hsub(subl) equals (116+-38) kJ/mol and ..delta..Ssub(subl) is equal to (198+-65) J/molxK.

  16. Determination of copper oxidizing power in superconducting yttrium ceramics

    International Nuclear Information System (INIS)

    Pontaler, R.P.; Lebed', N.B.

    1989-01-01

    A new photometric method for determining the formal copper degree of oxidation and oxygen deficiency in superconducting high-temperature oxides containing yttrium, barium and copper is developed. The method is based on oxidation of Co(2) complex with EDTA by Cu(3) ions in acetrate buffer solution with pH 4.2-4.7 and allows one to determine 1-10% of Cu(3). Relative standard deviation when determining Cu(3) makes up 0.03-0.05. Using a qualitative reaction with the application of sodium vanadate hydrochloride solution the absence of peroxide compound in superconducting yttrium ceramics is ascertained

  17. Lanthanide extraction with 2,5-dimethyl-2-hydroxyhexanoic acid

    International Nuclear Information System (INIS)

    Miller, J.H.

    1977-12-01

    This research is concerned with the solvent extraction into chloroform of the lanthanides, using 2,5-dimethyl-2-hydroxyhexanoic acid (DMHHA). This acid is the first α-hydroxy aliphatic acid to be studied as an extracting agent for the lanthanides. The chloroform-water DMHHA partition constant was determined to be 1.0 (at 0.1 M ionic strength and 25 0 C). The acid dimerizes in chloroform with a constant of 56. The light lanthanides can be extracted into chloroform by forming complexes with the DMHHA anions. The extracted metal species is highly aggregated. This extraction has a solubility limit which increases with the addition of unionized acid. The resultant extract is also highly aggregated. At unionized acid-to-metal ratios greater than one, extractions first occur followed by the slow precipitation of the lanthanide. At the tracer level, neodymium is extracted primarily as NdA 3 (HA) 5 and (NdA 3 ) 2 (HA)/sub q/. Very small amounts of (NdA 3 ) 2 and other metal aggregates are also present. The heavy lanthanides do not extract from solutions of DMHHA and its potassium salt, but form aqueous emulsions and precipitates. In the presence of the organic soluble tetrabutylammonium ion the heavy lanthanides can be extracted, presumably as ion pairs. The stability constants of the light lanthanides and DMHHA were determined. The separation factors obtained from DMHHA extractions of the light lanthanides were also investigated and found to be comparable to those obtained employing normal aliphatic carboxylic acid

  18. Why does the lumen maintenance of sodium-scandium metal halide lamps improve by VHF operation?

    International Nuclear Information System (INIS)

    Van Erk, W; Luijks, G M J F; Hitchcock, W

    2011-01-01

    Lifetime experiments show that sodium-scandium metal halide lamps perform better on very high frequency (VHF) drivers than on low frequency (LF) constant wattage autotransformer (CWA) ballasts. The question why, will be addressed with focus on arc tube aspects. It is argued that at high frequency operation sodium loss is less, and that the absence of thermal fluctuations in the electrode tip causes less damage and cracking to this part of the electrode. Sudden lm W -1 drops, observed with CWA-operated lamps, most probably occur when the arc attaches on such a corroded and cracked surface. Thorium is effective as an emitter both in the CWA and the VHF operation mode, despite the absence of cataphoretic transport to the cathode in the VHF case.

  19. Why does the lumen maintenance of sodium-scandium metal halide lamps improve by VHF operation?

    Energy Technology Data Exchange (ETDEWEB)

    Van Erk, W [Philips Lighting, Sondervick 47, 5505 NB Veldhoven (Netherlands); Luijks, G M J F [Advanced Development Lighting, Philips Lighting, PO Box 80020, 5600 JM Eindhoven (Netherlands); Hitchcock, W, E-mail: Gerard.luijks@philips.com [Philips Lighting Company, 7265 Route 54, Bath, NY 14810 (United States)

    2011-06-08

    Lifetime experiments show that sodium-scandium metal halide lamps perform better on very high frequency (VHF) drivers than on low frequency (LF) constant wattage autotransformer (CWA) ballasts. The question why, will be addressed with focus on arc tube aspects. It is argued that at high frequency operation sodium loss is less, and that the absence of thermal fluctuations in the electrode tip causes less damage and cracking to this part of the electrode. Sudden lm W{sup -1} drops, observed with CWA-operated lamps, most probably occur when the arc attaches on such a corroded and cracked surface. Thorium is effective as an emitter both in the CWA and the VHF operation mode, despite the absence of cataphoretic transport to the cathode in the VHF case.

  20. Influence of scandium on the microstructure and mechanical properties of A319 alloy

    International Nuclear Information System (INIS)

    Emadi, Daryoush; Rao, A.K. Prasada; Mahfoud, Musbah

    2010-01-01

    Recycling of aluminum scrap alloys by melting is gaining its importance in foundry sector. During recycling, some of the alloying elements present in scrap alloys eventually become trace/tramp impurities in the recycled alloy. These elements could potentially affect the alloy's microstructure and hence its mechanical properties. In the present work, an attempt has been made to investigate the effect of one of such trace elements on the microstructure and mechanical properties of A319 alloy. The element chosen for the present investigation is scandium (Sc). This paper discusses the effects of the additions of trace amount of Sc on the microstructure and mechanical properties of A319 alloy in as-cast, T6 and T7 heat treated conditions.

  1. Thermodynamic study of sublimation, melting and vaporization of scandium(III) dipivaloylmethanate derivatives

    International Nuclear Information System (INIS)

    Zherikova, Kseniya V.; Zelenina, Ludmila N.; Chusova, Tamara P.; Gelfond, Nikolay V.; Morozova, Natalia B.

    2016-01-01

    Highlights: • Thermal properties of two volatile fluorinated Sc(III) beta-diketonates were studied. • Saturated and unsaturated vapor pressures were measured. • DSC analysis was carried out. • Sublimation, evaporation and melting enthalpies and entropies were derived. • Effect of fluorine introduction on volatility and thermal stability was established. - Abstract: The present work deals with the investigation of thermal properties of two volatile scandium(III) beta-diketonates with 2,2,6,6-tetramethyl-4-fluoro-3,5-heptanedione and 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione which have been synthesized and purified. Using the static method with glass membrane gauge-manometer the temperature dependencies of saturated and unsaturated vapor pressure were measured for the first time. The temperatures and enthalpies of melting were measured for these compounds by differential scanning calorimetry. The standard thermodynamic characteristics of enthalpy and entropy for sublimation, vaporization and melting processes were derived.

  2. Dielectric matrix, dynamical matrix and phonon dispersion in hcp transition metal scandium

    International Nuclear Information System (INIS)

    Singh, Joginder; Singh, Natthi; Prakash, S.

    1976-01-01

    Complete dielectric matrix is evaluated for hcp transition metal scandium using the non-interacting s- and d-band model. The local field corrections which are consequence of the non-diagonal part of the dielectric matrix are calculated explicitly. The free electron approximation is used for the s-electrons and the simple tight-binding approximation is used for the d-electrons. The theory developed by Singh and others is used to invert the dielectric matrix and the explicit expressions for the dynamical matrix are obtained. The phonon dispersion relations are investigated by using the renormalized Animalu transition metal model potential (TMMP) for bare ion potential. The contribution due to non-central forces which arise due to local fields is found to be 20%. The results are found in resonably good agreement with the experimental values. (author)

  3. Bottom sediment transport study at Haiphong port using radioactive scandium as tracer

    International Nuclear Information System (INIS)

    Pham Ngoc Chuong; Phan Son Hai; Pham Duy Hien

    1993-01-01

    A radioisotope tracer experiment was performed for investigating the bedload movement at the site near the access channel to Haiphong port, North Vietnam. The scandium glass and a number of mechanical devices were manufactured locally for the experiment. Simple and safe procedures were adopted for the production, transportation and injection of radioactive tracer materials. Five tracking experiments were carried out covering the period of 84 days in winter 1992-1993. The experimental results provide a firm basis for elaborating appropriate measures against the siltation problem at Haiphong port, especially for the design of a new access channel with a better orientation with respect to the directions of the water flow and bedload transport, as proposed recently by the Port Authority. (Author). 2 refs, 4 figs

  4. Polysulfide coordination clusters of the lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ying-Zhao; Bestgen, Sebastian; Gamer, Michael T.; Roesky, Peter W. [Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Karlsruhe (Germany); Konchenko, Sergey N. [Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Karlsruhe (Germany); Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University (Russian Federation)

    2017-10-16

    The reaction of [(DippForm){sub 2}Ln(thf){sub 2}] with an excess of elemental sulfur in toluene resulted in the formation of the trinuclear polysulfide coordination clusters [(DippForm){sub 3}Ln{sub 3}S{sub 12}] (Ln=Sm, Yb; DippForm=N,N'-bis(2,6-diisopropylphenyl)formamidinate). These are the first f element coordination clusters (Ln{sub n}S{sub x}) with a larger polysulfide unit (n and x>2). The formation of the coordination clusters can be rationalized by the reductive cleavage of S{sub 8} with divalent lanthanides. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Modification mechanism of eutectic silicon in Al–6Si–0.3Mg alloy with scandium

    Energy Technology Data Exchange (ETDEWEB)

    Patakham, Ussadawut [Manufacturing and Systems Engineering Program, Department of Production Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, 126 Pracha-Utid Rd., Bangmod, Tungkhru, Bangkok 10140 (Thailand); Kajornchaiyakul, Julathep [National Metal and Material Technology Center, National Science and Technology Development Agency, 114 Thailand Science Park, Klong Nueng, Klong Luang, Pathumthani 12120 (Thailand); Limmaneevichitr, Chaowalit, E-mail: chaowalit.lim@kmutt.ac.th [Manufacturing and Systems Engineering Program, Department of Production Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, 126 Pracha-Utid Rd., Bangmod, Tungkhru, Bangkok 10140 (Thailand)

    2013-10-25

    Highlights: •Morphologies and growth of Sc and Sr-modified eutectic silicon resemble those of dendrites. •Crystal orientation of eutectic aluminum depends on growth characteristics of eutectic silicon. •We report strong evidence of the occurrence of an impurity-induced twinning mechanism. -- Abstract: The modification mechanism of eutectic silicon in Al–6Si–0.3Mg alloy with scandium was studied. The crystallographic orientation relationships between primary dendrites and the eutectic phase of unmodified and modified Al–6Si–0.3 Mg alloys were determined using electron backscatter diffraction (EBSD). The orientation of aluminum modified with scandium in the eutectic phase was different from that of the neighboring primary dendrites. This result implies that eutectic aluminum grows epitaxially from the surrounding primary aluminum dendrites in the unmodified alloy and that eutectic aluminum grows competitively from the surrounding primary aluminum dendrites in the modified alloy. The pole figure maps of eutectic Si in the [1 0 0], [1 1 0] and [1 1 1] axes of the unmodified and Sc-modified alloys were different, suggesting that the eutectic Al and Si crystals in modified alloy growth are more isotropic and cover a larger set of directions. The lattice fringes of Si of the alloys with and without Sc modification were different in the TEM results. The lattice fringes of Si in modified alloy were found to be multiple twins. However, this was not observed in the unmodified alloy. The growth characteristic of eutectic Si crystal in modified alloy suggests the occurrence of multiple twinning reactions and the formation of a high density of twins. This modification mechanism by Sc is explained by the results of scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analysis, which provide strong evidence of the occurrence of the impurity-induced twinning (IIT) mechanism.

  6. Insights into the mantle geochemistry of scandium from a meta-analysis of garnet data

    Science.gov (United States)

    Chassé, Mathieu; Griffin, William L.; Alard, Olivier; O'Reilly, Suzanne Y.; Calas, Georges

    2018-06-01

    The meta-analysis of about 13,000 analyses of scandium content in garnet grains shows that, below the spinel-garnet transition, this phase carries about three-quarters of the Sc budget of the mantle, indicating its control on Sc mobility. The Sc content of garnets in mafic rocks is low, due to a dilution effect resulting from their high modal content in garnet. Garnets from ultramafic rocks exhibit a wider range of Sc concentrations. We assess the relative influence of thermobarometry, crystal chemistry and fluid-related events on the distribution of Sc in garnet from such rocks to improve the tracking of geochemical processes in the mantle. Pressure and temperature of equilibration in the mantle are second-order factors influencing the Sc content of garnet, while crystal chemistry, in particular Cr/Cr+Al and Ca/Ca+Mg, is the main parameter controlling the compatibility of Sc. Scandium is incorporated in both X and Y sites of Cr-Ca-rich garnets, resulting in a behaviour intermediate between rare-earth elements, incorporated in the X site, and trivalent transition elements, occupying the Y site. This affinity for both sites results in a mild compatibility of Sc in the garnet stability field of the mantle; hence Sc concentration in garnet increases with melt extraction and can be reduced by silicate-melt metasomatism. In contrast, metasomatism by volatile-rich fluids increases the Sc concentration in garnet. The control of garnet on the compatibility of Sc in deep lithospheric rocks demonstrates the potential of using Sc to track the conditions of formation of magmas and their residual rocks, as well as the origin and nature of metasomatic fluids.

  7. Study of quantum dot based on tin/yttrium mixed oxide doped with terbium to be used as biomarker

    International Nuclear Information System (INIS)

    Paganini, Paula P.; Felinto, Maria Claudia F.C.; Kodaira, Claudia A.; Brito, Hermi F.; Nunes, Luiz Antonio O.

    2009-01-01

    Quantum dots (semiconductors nanocrystals) have brought a promising field to develop a new generation of luminescent biomarkers. The use of lanthanides ions as luminescent markers has many advantages, for example a security method, low cost, high specificity and also the luminescence can be promptly measured with high sensibility and accuracy. These luminescent dots are functionalized with biomolecules. For the luminophore particle to be connect with biologicals molecules (for example covalent antibody) is necessary a previous chemical treatment to modify luminophore particle surface and this process is called functionalization. A prior chemical treatment with changes on the surface luminophore particle is necessary to couple the luminophore to biological molecules. This process can be used as coating which can protect these particles from being dissolved by acid as well as provide functional groups for biological conjugation. This work presents a photoluminescence study of nanoparticles based on tin/yttrium mixed oxides doped with terbium (SnO 2 /Y 2 O 3 :Tb 3+ ), synthesized by coprecipitation method. The nanoparticles were submitted to thermal treatment and characterized by X-Ray Powder Diffraction (XRD) that showed cassiterite phase formation and the influence of thermal treatment on nanoparticles structures. These nanoparticles going to be functionalized with a natural polysaccharide (chitosan) in order to form microspheres. These microspheres going to be irradiated with gamma radiation to sterilization and it can be evaluated if the nanoparticles are resistant to irradiation and they do not lose functionality with this process. (author)

  8. Surface modifications induced by yttrium implantation on low manganese-carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Caudron, E.; Buscail, H. [Univ. Blaise Pascal Clermont-Fd II, Le Puy en Velay (France). Lab. Vellave d' Elaboration et d' Etude des Materiaux; Haanapel, V.A.C.; Jacob, Y.P.; Stroosnijder, M.F. [Institute for Health and Consumer Protection, Joint Research Center, The European Commission, 21020, Ispra (Italy)

    1999-12-15

    Low manganese-carbon steel samples were ion implanted with yttrium. Sample compositions and structures were investigated before and after yttrium implantations to determine the yttrium distribution in the sample. Yttrium implantation effects were characterized using several analytical and structural techniques such as X-ray photoelectron spectroscopy, reflection high energy electron diffraction, X-ray diffraction, glancing angle X-ray diffraction and Rutherford backscattering spectrometry. In this paper it is shown that correlation between composition and structural analyses provides an understanding of the main compounds induced by yttrium implantation in low manganese-carbon steel. (orig.)

  9. On the use of hydrogen peroxide as a masking agent for the determination of yttrium in uranium oxide - yttrium oxide mixture

    International Nuclear Information System (INIS)

    Rastogi, R.K.; Chaudhuri, N.K.; Rizvi, G.H.; Subramanian, M.S.

    1985-01-01

    The use of peroxide as a masking agent for uranium during the EDTA titration of yttrium in an yttrium-uranium mixture containing large amounts of uranium was investigated. High acetate ion concentration was necessary to keep the peroxy complex of uranium in solution during the titration. It was observed that uranium could be tolerated up to 500 mg in the determination of yttrium with 0.5 ml of 30% hydrogen peroxide in approx. 1M acetate medium. The precision and accuracy of the method based on 16 determinations of yttrium at 6-16 mg level in the presence of 300 mg uranium was found to be +-0.2%. (author)

  10. High performance yttrium-doped BSCF hollow fibre membranes

    DEFF Research Database (Denmark)

    Haworth, P.; Smart, S.; Glasscock, Julie

    2012-01-01

    measurements in air was similar for both compositions, suggesting that the higher oxygen fluxes obtained for BSCFY hollow fibres could be attributed to the higher non-stoichiometry due to yttrium addition to the BSCF crystal structure. In addition, the improvement of oxygen fluxes for small wall thickness (∼0...

  11. Microstructure and defect chemistry of yttrium aluminium garnet ceramics

    International Nuclear Information System (INIS)

    Schuh, L.H.

    1989-01-01

    This thesis describes basic aspects concerning the defect chemistry and the microstructure of yttrium aluminium garnet ceramics. The work consists of three parts: a literature study, an experimental part and a section giving computer simulation data of defects. (author). 320 refs.; 68 figs.; 72 schemes; 32 tabs

  12. A thermal neutron scattering law for yttrium hydride

    Science.gov (United States)

    Zerkle, Michael; Holmes, Jesse

    2017-09-01

    Yttrium hydride (YH2) is of interest as a high temperature moderator material because of its superior ability to retain hydrogen at elevated temperatures. Thermal neutron scattering laws for hydrogen bound in yttrium hydride (H-YH2) and yttrium bound in yttrium hydride (Y-YH2) prepared using the ab initio approach are presented. Density functional theory, incorporating the generalized gradient approximation (GGA) for the exchange-correlation energy, is used to simulate the face-centered cubic structure of YH2 and calculate the interatomic Hellmann-Feynman forces for a 2 × 2 × 2 supercell containing 96 atoms. Lattice dynamics calculations using PHONON are then used to determine the phonon dispersion relations and density of states. The calculated phonon density of states for H and Y in YH2 are used to prepare H-YH2 and Y-YH2 thermal scattering laws using the LEAPR module of NJOY2012. Analysis of the resulting integral and differential scattering cross sections demonstrates adequate resolution of the S(α,β) function. Comparison of experimental lattice constant, heat capacity, inelastic neutron scattering spectra and total scattering cross section measurements to calculated values are used to validate the thermal scattering laws.

  13. Structural and dielectric properties of yttrium substituted nickel ferrites

    International Nuclear Information System (INIS)

    Ognjanovic, Stevan M.; Tokic, Ivan; Cvejic, Zeljka; Rakic, Srdjan; Srdic, Vladimir V.

    2014-01-01

    Graphical abstract: - Highlights: • Dense NiFe 2−x Y x O 4 ceramics (with 0 ≤ x ≤ 0.3) were prepared. • Pure spinels were obtained for x ≤ 0.07 while for x ≥ 0.15 samples had secondary phases. • With addition of yttrium, ac conductivity slightly increased. • We suggest several effects that can explain the observed changes in ac conduction. • With addition of yttrium, dielectric constant increased while the tg δ decreased. - Abstract: The influence of Y 3+ ions on structural and dielectric properties of nickel ferrites (NiFe 2−x Y x O 4 , where 0 ≤ x ≤ 0.3) has been studied. The as-synthesized samples, prepared by the co-precipitation method, were analyzed by XRD and FTIR which suggested that Y 3+ ions were incorporated into the crystal lattice for all the samples. However, the XRD analysis of the sintered samples showed that secondary phases appear in the samples with x > 0.07. The samples have densities greater than 90% TD and the SEM images showed that the grain size decreases with the addition of yttrium. Dielectric properties measured from 150 to 25 °C in the frequency range of 100 Hz–1 MHz showed that the addition of yttrium slightly increases the ac conductivity and decreases the tg δ therefore making the materials better suited for the use in microwave devices

  14. Thermal decomposition of yttrium(III) hexanoate in argon

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Suarez Guevara, Maria Josefina; Attique, Fahmida

    2015-01-01

    The thermal decomposition of yttrium(III) hexanoate (Y(C5H11CO2)3)·xH2O in argon was studied by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction at a laboratory Cu-tube source and in-situ experiments at a synchrotron radiation source as well as hot...

  15. Thermal decomposition of Yttrium(III) isovalerate in argon

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Yue, Zhao; Tang, Xiao

    2016-01-01

    The thermal behaviour of yttrium(III) isovalerate (Y(C4H9CO2)3) was studied in argon by means of thermogravimetry, differential thermal analysis, FTIR-spectroscopy, hot-stage optical microscopy and X-ray diffraction with a laboratory Cu-tube source as well as with a synchrotron radiation source...

  16. Thermal decomposition of yttrium(III) valerate in argon

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Yue, Zhao; Tang, Xiao

    2014-01-01

    The thermal decomposition of yttrium(III) valerate (Y(C4H9CO2)3) was studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction, in-situ synchrotron diffraction and hot-stage microscopy as well as room temperature optical microscopy. Melting...

  17. Polymorphism and electrical behaviour of yttrium thin films

    International Nuclear Information System (INIS)

    Kaul, U.K.; Srivastava, O.N.

    1978-01-01

    It appears that the thickness-resistivity behaviour of yttrium embodying a thickness-dependent polymorphic phase transition can be explained in terms of surface scattering by taking into account the effect of the change in phase. It is interesting to note that, as a result of the polymorphic transition, the resistivity-thickness curve has an unusual shape. (Auth.)

  18. A new f.c.c. phase in yttrium films

    International Nuclear Information System (INIS)

    Kaul, V.K.; Srivastava, O.N.

    1976-01-01

    A new polymorphic phase characterised by a face-centered cubic structure, with lattice parameter 5.83 +- 0.02A, has been identified in thin films of yttrium. Electron diffraction evidence and electrical resistivity measurements have been carried out in order to detect the new f.c.c. phase. (Auth.)

  19. Multiscale Study of Hydrogen Adsorption on Six Designed Covalent Organic Frameworks Based on Porphyrazine, Cyclobutane and Scandium

    International Nuclear Information System (INIS)

    Li Le-Le; Gao Teng-Fei; Zhang Ruan-Yu; Zhang Hong

    2014-01-01

    The first-principles method of hydrogen adsorption is used to investigate the interaction of H_2 with the scandium-porphyrazine (Sc-Pz) and porphyrazine (Pz) clusters. The result shows that the interaction of H_2 with Sc-Pz is stronger than with Pz. Then grand canonical Monte Carlo simulations are used to investigate hydrogen adsorption in six designed covalent organic frameworks (COFs), which are designed based on porphyrazine, cyclobutane and scandium. When the pressure is from 0.1 to 100 bar and the temperature is 298 K and 77 K, the hydrogen adsorption capacities of the six COFs are calculated. We further study the importance of Sc and fillers to improve the H_2 uptake in the modified COFs by analyzing the isosteric heat of hydrogen adsorption. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  20. Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping

    KAUST Repository

    Wang, Feng; Han, Yu; Lim, Chinseong; Lu, Yunhao; Wang, Juan; Xu, Jun; Chen, Hongyu; Zhang, Chun; Hong, Minghui; Liu, Xiaogang

    2010-01-01

    or hexagonal) and upconversion emission colour (green to blue) through use of trivalent lanthanide dopant ions introduced at precisely defined concentrations. We use first-principles calculations to confirm that the influence of lanthanide doping on crystal

  1. Evidence of yttrium silicate inclusions in YSZ-porcelain veneers.

    Science.gov (United States)

    Stoner, Brian R; Griggs, Jason A; Neidigh, John; Piascik, Jeffrey R

    2014-04-01

    This report introduces the discovery of crystalline defects that can form in the porcelain veneering layer when in contact with yttria-stabilized zirconia (YSZ). The focus was on dental prostheses and understanding the defects that form in the YSZ/porcelain system; however the data reported herein may have broader implications toward the use and stability of YSZ-based ceramics in general. Specimens were cut from fully sintered YSZ plates and veneering porcelain was applied (X-ray (EDAX) was used for microstructural and elemental analysis. EDAX, for chemical analysis and transmission electron diffraction (TED) for structural analysis were both performed in the transmission electron microscope (TEM). Additionally, in order to spatially resolve Y-rich precipitates, micro-CT scans were conducted at varying depths within the porcelain veneer. Local EDAX (SEM) was performed in the regions of visible inclusions and showed significant increases in yttrium concentration. TEM specimens also showed apparent inclusions in the porcelain and selected area electron diffraction was performed on these regions and found the inclusions to be crystalline and identified as either yttrium-silicate (Y2 SiO5 ) or yttrium-disilicate (Y2 Si2 O7 ). Micro-CT data showed that yttrium-silicate precipitates were distributed throughout the thickness of the porcelain veneer. Future studies are needed to determine whether many of the premature failures associated with this materials system may be the result of crystalline flaws that form as a result of high temperature yttrium diffusion near the surfaces of YSZ. © 2013 Wiley Periodicals, Inc.

  2. Yttrium-90 microspheres for the treatment of hepatocellular carcinoma.

    Science.gov (United States)

    Geschwind, Jean Francois H; Salem, Riad; Carr, Brian I; Soulen, Michael C; Thurston, Kenneth G; Goin, Kathleen A; Van Buskirk, Mark; Roberts, Carol A; Goin, James E

    2004-11-01

    Unresectable hepatocellular carcinoma is extremely difficult to treat. TheraSphere consists of yttrium-90 (a pure beta emitter) microspheres, which are injected into the hepatic arteries. This article reviews the safety and survival of patients with hepatocellular carcinoma who were treated with yttrium-90 microspheres. Eighty patients were selected from a database of 108 yttrium-90 microsphere-treated patients and were staged by using Child-Pugh, Okuda, and Cancer of the Liver Italian Program scoring systems. Patients were treated with local, regional, and whole-liver approaches. Survival from first treatment was analyzed with Kaplan-Meier and Cox regression methods. Adverse events and complications of treatment were coded by using the Southwest Oncology Group toxicity scoring system. Patients received liver doses ranging from 47 to 270 Gy. Thirty-two patients (40%) received more than 1 treatment. Survival correlated with pretreatment Cancer of the Liver Italian Program scores ( P = .002), as well as with the individual Cancer of the Liver Italian Program components, Child-Pugh class, alpha-fetoprotein levels, and percentage of tumor replacement. Patients classified as Okuda stage I (n = 54) and II (n = 26) had median survival durations and 1-year survival rates of 628 days and 63%, and 384 days and 51%, respectively ( P = .02). One patient died of liver failure judged as possibly related to treatment. Thus, in selected patients with hepatocellular carcinoma, yttrium-90 microsphere treatment is safe and well tolerated. On the basis of these results, a randomized controlled trial is warranted comparing yttrium-90 microsphere treatment with transarterial chemoembolization by using the Cancer of the Liver Italian Program system for prospective stratified randomization.

  3. Electronic, magnetic, and magnetocrystalline anisotropy properties of light lanthanides

    Science.gov (United States)

    Hackett, Timothy A.; Baldwin, D. J.; Paudyal, D.

    2017-11-01

    Theoretical understanding of interactions between localized and mobile electrons and the crystal environment in light lanthanides is important because of their key role in much needed magnetic anisotropy in permanent magnet materials that have a great impact in automobile and wind turbine applications. We report electronic, magnetic, and magnetocrystalline properties of these basic light lanthanide elements studied from advanced density functional theory (DFT) calculations. We find that the inclusion of onsite 4f electron correlation and spin orbit coupling within the full-potential band structure is needed to understand the unique magnetocrystalline properties of these light lanthanides. The onsite electron correlation, spin orbit coupling, and full potential for the asphericity of charge densities must be taken into account for the proper treatment of 4f states. We find the variation of total energy as a function of lattice constants that indicate multiple structural phases in Ce contrasting to a single stable structure obtained in other light lanthanides. The 4f orbital magnetic moments are partially quenched as a result of crystalline electric field splitting that leads to magnetocrystalline anisotropy. The charge density plots have similar asphericity and environment in Pr and Nd indicating similar magnetic anisotropy. However, Ce and Sm show completely different asphericity and environment as both orbital moments are significantly quenched. In addition, the Fermi surface structures exemplified in Nd indicate structural stability and unravel a cause of anisotropy. The calculated magnetocrystalline anisotropy energy (MAE) reveals competing c-axis and in-plane anisotropies, and also predicts possibilities of unusual structural deformations in light lanthanides. The uniaxial magnetic anisotropy is obtained in the double hexagonal closed pack structures of the most of the light lanthanides, however, the anisotropy is reduced or turned to planar in the low symmetry

  4. Scandium interaction with diantipyrylmethane homologues and 2-(n-sulphophenylazo)-1,8-dihydroxynaphthalene-3,6 sodium disulphonate

    Energy Technology Data Exchange (ETDEWEB)

    Ganago, L I; Alinovskaya, L A [AN Belorusskoj SSR, Minsk. Inst. Fiziki Tverdogo Tela i Poluprovodnikov

    1979-01-01

    The reactions of scandium with homologs of diantipyrilmethane (DAM)-propyldiantipyrilmethane (PDAM) and phenyldiantipyrilmethane (PhDAM) - are studied. The relationship of components in the complexes formed is found, and chemism of their formation is established. The complexes Sc-SPADNE (sodium salt 2-(n-sulphophenylazo)-1,8-dioxynaphthalene-3,6-disulphonic acid) are shown to form within a wide pH range. The maximum yield of complexes is observed at 6.0-7.5 pH. By the ion-exchange method the anion character of heteroligand scandium complexes is established. The complex Sc-SPADNE-PDAM is faster as compared with the complexes Sc-SPADNE-DAM and Sc-SPADNE-PhDAM. The decrease in amine excess and increase in the sensitivity of heteroligand formation of the complexes of scandium with SPADNE and PDAM make them better suited for analysis. The technique is developed for the determination of Sc/sub 2/O/sub 3/ in perovskites using the complete differential spectrophotometry method.

  5. Lanthanide-doped nanoparticles as the active optical medium in polymer-based devices

    NARCIS (Netherlands)

    Stouwdam, J.W.

    2004-01-01

    The luminescence of lanthanide ions in organic environment is greatly reduced compared to inorganic materials. This thesis describes the doping of the lanthanide ions in the core of inorganic nanoparticles that are soluble in organic solvents as a way to shield the lanthanide ions from the organic

  6. Calorimetric approach of lanthanides (3) complexation and extraction by malonamides

    International Nuclear Information System (INIS)

    Flandin, J.L.

    2001-01-01

    In the field of long lived radionuclides separation, diamides are interesting extractants because of their ability to co-extract trivalent lanthanides and actinides, which is a preliminary and essential step in high level radioactive waste reprocessing. The research carried out contributes to a better understanding of the mechanisms and the aim is the determination of thermodynamics properties (Δ r G, Δ r H et Δ r S) related to the complexation and the extraction of lanthanides(III) by malonamides. The first part of the document deals with the complexation of lanthanides(III) by an hydrosoluble diamide. The experimental results obtained by UV-visible spectrometry, TRLIF, NMR and microcalorimetric titration proved that lanthanides(III)-TEMA interactions in aqueous medium are very weak and that the complexation reaction is endothermic. The TEMA ligand still stays in the second coordination sphere of coordination of the lanthanide ion. The second part of this study focuses on the extraction of neodymium(III) nitrate by a lipophilic diamide which is an exothermic reaction. The influence of the composition of aqueous and organic phases on the thermodynamics properties Δ r G et Δ r H has been studied by microcalorimetric titration. The most influent parameter is the total concentration in extractant. As a consequence, thermodynamic values are very dependent on the organic phase organisation before and alter extraction. At the same time, this study showed the interest of the calorimetric approach for the analysis of basic reactions like diamide dilution and their organisation as oligomeric aggregates. (author)

  7. High performance separation of lanthanides and actinides

    International Nuclear Information System (INIS)

    Sivaraman, N.; Vasudeva Rao, P.R.

    2011-01-01

    The major advantage of High Performance Liquid Chromatography (HPLC) is its ability to provide rapid and high performance separations. It is evident from Van Deemter curve for particle size versus resolution that packing materials with particle sizes less than 2 μm provide better resolution for high speed separations and resolving complex mixtures compared to 5 μm based supports. In the recent past, chromatographic support material using monolith has been studied extensively at our laboratory. Monolith column consists of single piece of porous, rigid material containing mesopores and micropores, which provide fast analyte mass transfer. Monolith support provides significantly higher separation efficiency than particle-packed columns. A clear advantage of monolith is that it could be operated at higher flow rates but with lower back pressure. Higher operating flow rate results in higher column permeability, which drastically reduces analysis time and provides high separation efficiency. The above developed fast separation methods were applied to assay the lanthanides and actinides from the dissolver solutions of nuclear reactor fuels

  8. Synthesis and characterization of lanthanide picrate complexes with 4-picoline-N-oxide (4-pic N O)

    International Nuclear Information System (INIS)

    Silva, E.M. da.

    1991-01-01

    The lanthanide picrate complexes with 4-picoline-N-oxide were obtained from ethanolic solutions of the hydrated lanthanide picrate and the ligand. The lanthanide content was determined by complexometric titration with EDTA. Carbon, Nitrogen and Hydrogen were determined by microanalytical procedures. Chemical analysis of the lanthanide picrate complexes are also presented. (author)

  9. Determination of stability constants of lanthanide complexes with tetracycline

    International Nuclear Information System (INIS)

    Saiki, Mitiko

    1975-01-01

    The stability constants of complexes compounds formed with tetracycline and lanthanides elements were determined for all lanthanides except promethium. The experimental procedure used was solvent extraction of the lanthanides labelled with their radioactive isotopes. It was shown that the formed complexes are mononuclear and that no hydroxo complexes or negatively charged complexes are formed in the experimental conditions of this work. Four methods of calculation were used for all complexes studied: the method of the average number of ligands, the method of limiting value, the method of two parameters and the method of weighted least squares. A comparison was made of the graphical methods with the method of least squares, showing the convenience of preceding least squares calculation by the graphical methods, in order to verify eventual mistakes of numerical data. It was shown the advantage of using radioisotopes of the elements for such a study, specially if the solvent extraction technique is used to-get the experimental data. (author)

  10. Lanthanide and actinide complexation studies with tetradentate 'N' donor ligands

    International Nuclear Information System (INIS)

    Bhattacharyya, A.; Mohapatra, M.; Mohapatra, P.K.; Rawat, N.; Tomar, B.S.; Gadly, T.; Ghosh, S.K.; Manna, D.; Ghanty, T.K.

    2014-01-01

    Because of their similar charge and chemical behaviour separation of trivalent actinides and lanthanides is an important and challenging task in nuclear fuel cycle. Soft (S,N) donor ligands show selectivity towards the trivalent actinides over the lanthanides. Out of various 'N' donor ligands studied, bis(1,2,4)triazinyl bipyridine (BTBP) and bis(1,2,4)triazinyl phenanthroline (BTPhen) were found to be most promising. In order to understand the separation behaviour of these ligands, their complexation studies with these 'f' block elements are essential. In the present work, complexation studies of various lanthanide ions (La 3+ , Eu 3+ and Er 3+ ) was studied with ethyl derivatives of BTBP (C 2 BTBP) and BTBPhen (C 2 BTPhen) and pentyl derivative of BTBP (C 5 BTBP) in acetonitrile medium using UV-Vis spectrophotometry, fluorescence spectroscopy and solution calorimetry. Computational studies were also carried out to understand the experimental results

  11. The electronic structure of the lanthanides and actinides, a comparison

    International Nuclear Information System (INIS)

    Edelstein, N.M.

    1998-01-01

    Full text: Optical spectra of the two f-element series (the lanthanides and actinides) are comparable in many respects. For the trivalent ions isolated in single crystals, both series exhibit rich, narrow line spectra. These data can be analysed in terms of a parametric model based on a free-ion Hamiltonian plus the addition of a crystal field Hamiltonian. For most systems the agreement between the calculated and experimental energy levels is quite good. In the actinide series there appears to be a correlation between the magnitude of the crystal field and the inadequacy of the fits. The early actinides exhibit multiple oxidation states for which there is no precedent in the lanthanide series. The parametric model mentioned earlier has been utilized for some tetravalent actinide systems with reasonably good results. A selective survey of results describing the similarities and differences of various lanthanide and actinide systems will be given

  12. 'Americium(III)/trivalent lanthanides' separation using organothiophosphinic acids

    International Nuclear Information System (INIS)

    Hill, C.; Madic, C.; Baron, P.; Ozawa, Masaki; Tanaka, Yasumasa.

    1997-01-01

    The present paper describes the extraction of neodymium and other lanthanides by saponified Cyanex 301 acid. The saponification of commercial Cyanex 301 acid favoured the extraction of macro concentrations of neodymium from sodium nitrate aqueous solutions (pH eq ∼ 4). The amount of lanthanide extracted in the organic phase always reached the third of the initial concentration of saponified Cyanex 301 acid, which assumed a cation exchange mechanism to occur during the extraction. No nitrate anion took part in the complex formation. This paper also compares the abilities of purified Cyanex 301, Cyanex 302 and Cyanex 272 acids to extract and separate 241 Am(III) from 152 Eu(III). Very high separation factors S.F. Am/Eu were observed in the case of purified Cyanex 301 acid. Finally some studies are presented herein using tri-n-butylphosphate (TBP) as a synergistic extractant with Cyanex 301 acid to separate actinides from trivalent lanthanide. (author)

  13. Separation of lanthanides using micro solvent extraction system

    International Nuclear Information System (INIS)

    Nishihama, S.; Tajiri, Y.; Yoshizuka, K.

    2006-01-01

    A micro solvent extraction system for the separation of lanthanides has been investigated. The micro flow channel is fabricated on a poly(methyl methacrylate) (PMMA) plate, and solvent extraction progresses by feeding aqueous and organic solutions into the channel simultaneously. The extraction equilibrium is quickly achieved, without any mechanical mixing, when a narrow channel (100 μm width and 100 μm depth) is used. The results of solvent extraction from the Pr/Nd and Pr/Sm binary solutions revealed that both lanthanides are firstly extracted together, and then, the lighter lanthanide extracted in the organic solution alternatively exchanges to the heavier one in the aqueous solution to achieve the extraction equilibrium. The phase separation of the aqueous and organic phases after extraction can also be successively achieved by contriving the cross section of the flow channel, and the extractive separation of Pr/Sm is demonstrated. (authors)

  14. Preparation of high purity yttrium single crystals by electrotransport

    International Nuclear Information System (INIS)

    Volkov, V.T.; Nikiforova, T.V.; Ionov, A.M.; Pustovit, A.N.; Sikharulidse, G.G.

    1981-01-01

    The possibility of obtaining yttrium crystals of high purity by the method of solid state electrotransport (SSE) was investigated in the present work. The behaviour of low contents of iron, aluminium, silicon, tantalum, copper, silver and vanadium as metallic impurities was studied using mass spectrometry. It is shown that all the impurities investigated, except copper, migrate to the anode. During electrotransfer a purification with respect to these impurities by a factor of 4 - 6 is obtained. It is proposed that the diffusion coefficients of the metallic impurities investigated are anomalously high and that the behaviour of the impurities during SSE in adapters necessitates further investigation. By using a three-stage process with intermediate removal of the anode end yttrium single crystals with a resistance ratio rho 293 /rhosub(4.2)=570 were produced. (Auth.)

  15. Thermodynamical properties of liquid lanthanides-A variational approach

    Energy Technology Data Exchange (ETDEWEB)

    Patel, H. P. [Department of Physics, Veer Narmad South Gujarat University, Surat 395 007, Gujarat (India); Department of Applied Physics, S. V. National Institute of Technology, Surat 395 007, Gujarat (India); Thakor, P. B., E-mail: pbthakor@rediffmail.com [Department of Physics, Veer Narmad South Gujarat University, Surat 395 007, Gujarat (India); Sonvane, Y. A. [Department of Applied Physics, S. V. National Institute of Technology, Surat 395 007, Gujarat (India)

    2015-06-24

    Thermodynamical properties like Entropy (S), Internal energy (E) and Helmholtz free energy (F) of liquid lanthanides using a variation principle based on the Gibbs-Bogoliubuv (GB) inequality with Percus Yevick hard sphere reference system have been reported in the present investigation. To describe electron-ion interaction we have used our newly constructed parameter free model potential along with Sarkar et al. local field correction function. Lastly, we conclude that our newly constructed model potential is capable to explain the thermodynamical properties of liquid lanthanides.

  16. Microwave synthesis of nanostructured oxide sorbents doped with lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Mitrofanov, Andrey A., E-mail: mitrofanov-a@icloud.com; Silyavka, Elena S.; Shilovskikh, Vladimir V.; Kolonitckii, Petr D.; Sukhodolov, Nikolai G.; Selyutin, Artem A., E-mail: selutin@inbox.ru [Saint Petersburg State University, 7/9, Universitetskaya nab., St. Petersburg, 199034 (Russian Federation)

    2016-06-17

    A number of nanostructured mesoporous oxide systems based on aluminum oxide, doped with lanthanide ions have been obtained in this study. Structure and morphology of oxides obtained have been examined by X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy. The surface area of the samples was determined by the BET method. The dependence of the adsorption of insulin on synthesized oxides from the concentration was investigated. The containing of insulin in solutions after adsorption was determined by the Bradford method. The isotherms of adsorption of insulin on resulting oxide sorbents were plotted, the dependence capacity of the sorption of insulin from the lanthanide dopant was determined.

  17. Electrospray mass spectrometry for actinides and lanthanide speciation

    International Nuclear Information System (INIS)

    Moulin, C.; Amekraz, B.; Colette, S.; Doizi, D.; Jacopin, C.; Lamouroux, C.; Plancque, G.

    2006-01-01

    Electrospray mass spectrometry (ES-MS) is a new speciation technique that has the great interest to be able to probe the element, the ligand and the complex in order to reach the speciation. This paper will focus on the use of ES-MS for the speciation of actinides/lanthanides on several systems of interest in various fields such as the interaction between DTPA (decorporant) and europium, HEBP and uranium, BTP (new extracting agent) and lanthanides with comparison with known chemistry as well as whenever possible with other speciation techniques

  18. Separation of lanthanides through hydroxyapatite; Separacion de lantanidos mediante hidroxiapatita

    Energy Technology Data Exchange (ETDEWEB)

    Garcia M, F.G

    2006-07-01

    With the objective of obtaining from an independent way to each one of the lanthanides {sup 151} Pm, {sup 161} Tb, {sup 166} Ho and {sup 177} Lu free of carrier and with high specific activities starting from the indirect irradiation via, it intends in this work to determine the viability of separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu, by means of ion exchange column chromatography, using hydroxyapatite (HAp) and fluorite like absorbent material in complexing media. It is important to mention that have registered separation studies among lanthanides of the heavy group with those of the slight group, using the same mass and, in comparison with this work, quantities different from the father were used and of the son, also, that the separation studies were carried out among neighboring lanthanides. In this investigation, it was determined the effect that its have the complexing media: KSCN, sodium tartrate, sodium citrate, EDTA and aluminon, their pH and concentration, in the adsorption of the lanthanides in both minerals, in order to determine the chromatographic conditions for separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu. The work consists of five chapters, in the first one they are presented a theoretical introduction of the characteristics more important of the lanthanides, the hydroxyapatite and the fluorite; in the second, it is deepened in the ion exchange, as well as the two techniques (XRD and High Vacuum Electron Microscopy) to make the characterization of LnCI{sub 3} (Ln = Nd, Gd, Dy or Yb) synthesized. The third chapter, it describes the methodology continued in our experimental work; in the room, its are presented the obtained results of the static and dynamic method to determine the viability of separation of neighboring lanthanides; and finally, the five chapter shows the conclusions. In this study, it is concludes that the separation among neighboring lanthanides cannot be carried out in the minerals and used media; because

  19. SOLVENT EXTRACTION PROCESS FOR SEPARATING ACTINIDE AND LANTHANIDE METAL VALUES

    Science.gov (United States)

    Hildebrandt, R.A.; Hyman, H.H.; Vogler, S.

    1962-08-14

    A process of countercurrently extracting an aqueous mineral acid feed solution for the separation of actinides from lanthanides dissolved therern is described. The feed solution is made acid-defrcient with alkali metal hydroxide prior to.contact with acid extractant; during extraction, however, acid is transferred from organic to aqueous solution and the aqueous solution gradually becomes acid. The acid-deficient phase ' of the process promotes the extraction of the actinides, while the latter acid phase'' of the process improves retention of the lanthanides in the aqueous solution. This provides for an improved separation. (AEC)

  20. Characterization and thermogravimetric analysis of lanthanide hexafluoroacetylacetone chelates.

    Science.gov (United States)

    Shahbazi, Shayan; Stratz, S Adam; Auxier, John D; Hanson, Daniel E; Marsh, Matthew L; Hall, Howard L

    2017-01-01

    This work reports the thermodynamic characterizations of organometallic species as a vehicle for the rapid separation of volatile nuclear fission products via gas chromatography due to differences in adsorption enthalpy. Because adsorption and sublimation thermodynamics are linearly correlated, there is considerable motivation to determine sublimation enthalpies. A method of isothermal thermogravimetric analysis, TGA-MS and melting point analysis are employed on thirteen lanthanide 1,1,1,5,5,5-hexafluoroacetylacetone complexes to determine sublimation enthalpies. An empirical correlation is used to estimate adsorption enthalpies of lanthanide complexes on a quartz column from the sublimation data. Additionally, four chelates are characterized by SC-XRD, elemental analysis, FTIR and NMR.

  1. Phenomenological theory of the dielectric response of lead magnesium niobate and lead scandium tantalate

    International Nuclear Information System (INIS)

    Qian, H.; Bursill, L.A.

    1997-01-01

    The influence of the random field effects originating from charges chemical defects and non-domain textures of the formation and dynamics of polar clusters is analyzed. The spatial distribution of the local fields is not totally random but contains some correlations in direction and strength. Polar clusters are classified to be dynamic or frozen according to their dynamic characteristics in the random fields. The relaxation formula of a dipolar moment in an anisotropic double-well potential is deduced. Two percolation models are introduced, one to account for frustration effects associated with multiple orientations of polar clusters, which results in a broad diffuse dielectric response and the second to account for the case whereby there may be a phase transition to a ferroelectric state. The dielectric permittivity and dissipation factor of the typical relaxors lead magnesium niobate and lead scandium tantalate are predicted as a function of both temperature and frequency, which results are in good agreement with the experimental measurements. 30 refs., 9 figs

  2. Microstructure and age-hardening effects of aluminium alloys with additions of scandium and zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Galun, R.; Mordike, B.L. [Inst. fuer Werkstoffkunde und Werkstofftechnik, Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany); Maiwald, T.; Smola, B. [Zentrum fuer Funktionswerkstoffe GmbH, Clausthal-Zellerfeld (Germany); Mergen, R.; Manner, M.; Uitz, W. [Miba Gleitlager GmbH, Laakirchen (Australia)

    2004-12-01

    The aim of the work presented in this report was to produce age-hardenable aluminium alloys containing scandium and zirconium by a casting process with similar cooling conditions like an industrial casting process. Microstructure, precipitation structure and age-hardening response of different alloys with up to 0.4 wt.% Sc and Zr were investigated. Age-hardening experiments from the as-cast condition without solution annealing showed a significant increase of hardness of about 100% for Sc-rich alloys and of 50% for Zr-rich alloys compared to the as-cast condition. TEM investigations revealed the formation of precipitates of ternary Al{sub 3}(Sc{sub x}Zr{sub 1-x}) phases with a cubic cP4 crystal structure. In addition to the strengthening effect, a high thermal stability especially of the precipitates in Zr-rich alloys up to 400 C let these alloys look very promising for high-temperature applications. (orig.)

  3. Partitioning of Iron and Scandium in Soils Having Water Drainage Limitations

    International Nuclear Information System (INIS)

    Aide, M.; Braden, I.; Mueller, W.

    2010-01-01

    Soil chemistry of Fe includes weathering reactions, adsorption, hydrolysis, complexation, and oxidation-reduction reactions. Soil chemistry for scandium (Sc) is similar, but Sc does not include oxidation-reduction reactions. To determine if geochemical analysis may be used to identify Sc partitioning with respect to Fe among the particle size fractions, two Alfisol and two Ultisol soils were assessed using an aqua-regia digestion to estimate Sc and Fe concentrations for whole soil and particle size separates. Aqua-regia digestion data showed Sc depletion relative to Fe in sand separate. Sand separate is largely composed on quartz sand and Fe-Mn-bearing nodules, which are redoximorphic features produced by alternating oxic and suboxic/anoxic conditions associated with seasonally fluctuating water tables. Relative partitioning of Fe and Sc in these soils warrants further study to assess if selective extractions could quantify the extent of modern or ancestral oxidation-reduction processes responsible in some soil features involved in soil genesis.

  4. Effect of Aqueous Media on the Recovery of Scandium by Selective Precipitation

    Directory of Open Access Journals (Sweden)

    Bengi Yagmurlu

    2018-05-01

    Full Text Available This research presents a novel precipitation method for scandium (Sc concentrate refining from bauxite residue leachates and the effect of aqueous media on this triple-stage successive precipitation process. The precipitation pattern and the precipitation behavior of the constituent elements was investigated using different precipitation agents in three major mineral acid media, namely, H2SO4, HNO3, and HCl in a comparative manner. Experimental investigations showed behavioral similarities between HNO3 and HCl media, while H2SO4 media was different from them because of the nature of the formed complexes. NH4OH was found to be the best precipitation agent in every leaching media to remove Fe(III with low Sc co-precipitation. To limit Sc loss from the system, Fe(III removal was divided into two steps, leading to more than 90% of Fe(III removal at the end of the process. Phosphate concentrates were produced in the final step of the precipitation process with dibasic phosphates which have a strong affinity towards Sc. Concentrates containing more than 50% of ScPO4 were produced in each case from the solutions after Fe(III removal, as described. A flow diagram of the selective precipitation process is proposed for these three mineral acid media with their characteristic parameters.

  5. Adsorption of hydrogen in Scandium/Titanium decorated nitrogen doped carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Mananghaya, Michael, E-mail: mikemananghaya@gmail.com [De La Salle University, 2401 Taft Ave, 0922, Manila (Philippines); DLSU STC Laguna Boulevard, LTI Spine Road Barangays Biñan and Malamig, Biñan City, Laguna (Philippines); DOST-ASTHRDP, PCIEERD, Gen. Santos Ave., Bicutan, Taguig City 1631 (Philippines); Belo, Lawrence Phoa; Beltran, Arnel [De La Salle University, 2401 Taft Ave, 0922, Manila (Philippines); DLSU STC Laguna Boulevard, LTI Spine Road Barangays Biñan and Malamig, Biñan City, Laguna (Philippines)

    2016-09-01

    Nitrogen doped Carbon Nanotube with divacancy (4ND-CN{sub x}NT) that is decorated with Scandium and Titanium as potential hydrogen storage medium using the pseudo potential density functional method was investigated. Highly localized states near the Fermi level, which are derived from the nitrogen defects, contribute to strong Sc and Ti bindings, which prevent metal aggregation and improve the material stability. A detailed Comparison of the Hydrogen adsorption capability with promising system-weight efficiency of Sc over Ti was elucidated when functionalized with 4ND-CN{sub x}NT. Finally, the (Sc/4ND){sub 10}-CN{sub x}CNT composite material has a thermodynamically favorable adsorption and consecutive adsorption energy for ideal reversible adsorption and desorption of hydrogen at room temperature such that it can hold at least 5.8 wt% hydrogen molecules at the LDA and GGA level. - Highlights: • Carbon Nanotube with divacancy (4ND-CN{sub x}NT) decorated with Sc and Ti. • Nitrogen defects, contribute to strong Sc and Ti bindings. • H{sub 2} and (Sc/4ND){sub 10}-CN{sub x}CNT has a favorable adsorption. • 5.8 wt% adsorption at the LDA and GGA level.

  6. China's rare-earth industry

    Science.gov (United States)

    Tse, Pui-Kwan

    2011-01-01

    Introduction China's dominant position as the producer of over 95 percent of the world output of rare-earth minerals and rapid increases in the consumption of rare earths owing to the emergence of new clean-energy and defense-related technologies, combined with China's decisions to restrict exports of rare earths, have resulted in heightened concerns about the future availability of rare earths. As a result, industrial countries such as Japan, the United States, and countries of the European Union face tighter supplies and higher prices for rare earths. This paper briefly reviews China's rare-earth production, consumption, and reserves and the important policies and regulations regarding the production and trade of rare earths, including recently announced export quotas. The 15 lanthanide elements-lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium (atomic numbers 57-71)-were originally known as the rare earths from their occurrence in oxides mixtures. Recently, some researchers have included two other elements-scandium and yttrium-in their discussion of rare earths. Yttrium (atomic number 39), which lies above lanthanum in transition group III of the periodic table and has a similar 3+ ion with a noble gas core, has both atomic and ionic radii similar in size to those of terbium and dysprosium and is generally found in nature with lanthanides. Scandium (atomic number 21) has a smaller ionic radius than yttrium and the lanthanides, and its chemical behavior is intermediate between that of aluminum and the lanthanides. It is found in nature with the lanthanides and yttrium. Rare earths are used widely in high-technology and clean-energy products because they impart special properties of magnetism, luminescence, and strength. Rare earths are also used in weapon systems to obtain the same properties.

  7. Acromegaly with sleep disturbances relieved by yttrium-90 pituitary implantation

    International Nuclear Information System (INIS)

    Rosenstock, J.; Doyle, F.H.; Joplin, G.F.; Jung, R.T.; Mashiter, K.

    1982-01-01

    A brief case history is presented of a patient, who, after yttrium-90 implantation, showed a complete clinical and hormonal remission of her acromegaly, maintaining normal pituitary function. The remarkable feature was the rapid disappearance of her attacks of somnolence within 96 hours of pituitary implantation, despite persistence of nocturnal snoring and well before any remodelling of soft tissues could have occurred. This response suggests that her daytime somnolence had a narcoleptic component. (author)

  8. Temperature dependence of sound velocity in yttrium ferrite

    International Nuclear Information System (INIS)

    L'vov, V.A.

    1979-01-01

    The effect of the phonon-magnon and phonon-phonon interoctions on the temperature dependence of the longitudinal sound velocity in yttrium ferrite is considered. It has been shown that at low temperatures four-particle phonon-magnon processes produce the basic contribution to renormalization of the sound velocity. At higher temperatures the temperature dependence of the sound velocity is mainly defined by phonon-phonon processes

  9. Acromegaly with sleep disturbances relieved by yttrium-90 pituitary implantation

    Energy Technology Data Exchange (ETDEWEB)

    Rosenstock, J.; Doyle, F.H.; Joplin, G.F.; Jung, R.T.; Mashiter, K. (Hammersmith Hospital, London (UK). Postgraduate Medical School)

    1982-03-01

    A brief case history is presented of a patient, who, after yttrium-90 implantation, showed a complete clinical and hormonal remission of her acromegaly, maintaining normal pituitary function. The remarkable feature was the rapid disappearance of her attacks of somnolence within 96 hours of pituitary implantation, despite persistence of nocturnal snoring and well before any remodelling of soft tissues could have occurred. This response suggests that her daytime somnolence had a narcoleptic component.

  10. Growth and scintillation properties of gadolinium and yttrium orthovanadate crystals

    International Nuclear Information System (INIS)

    Voloshina, O.V.; Baumer, V.N.; Bondar, V.G.; Kurtsev, D.A.; Gorbacheva, T.E.; Zenya, I.M.; Zhukov, A.V.; Sidletskiy, O.Ts.

    2012-01-01

    Aiming to explore the possibility of using the undoped rare-earth orthovanadates as scintillation materials, we developed the procedure for growth of gadolinium (GdVO 4 ) and yttrium (YVO 4 ) orthovanadate single crystals by Czochralski method, and determined the optimal conditions of their after-growth annealing. Optical, luminescent, and scintillation properties of YVO 4 and GdVO 4 were discussed versus known literature data. Scintillation characteristics of GdVO 4 were determined for the first time.

  11. Treatment of exhaust fluorescent lamps to recover yttrium: Experimental and process analyses

    International Nuclear Information System (INIS)

    De Michelis, Ida; Ferella, Francesco; Varelli, Ennio Fioravante; Veglio, Francesco

    2011-01-01

    Highlights: → Recovery of yttrium from spent fluorescent lamps by sulphuric acid leaching. → The use of sulphuric acid allows to reduce calcium dissolutions. → Main contaminant of fluorescent powder are Si, Pb, Ca and Ba. → Hydrated yttrium oxalate, recovered by selective precipitation, is quite pure (>90%). → We have studied the whole process for the treatment of dangerous waste (plant capability). - Abstract: The paper deals with recovery of yttrium from fluorescent powder coming from dismantling of spent fluorescent tubes. Metals are leached by using different acids (nitric, hydrochloric and sulphuric) and ammonia in different leaching tests. These tests show that ammonia is not suitable to recover yttrium, whereas HNO 3 produces toxic vapours. A full factorial design is carried out with HCl and H 2 SO 4 to evaluate the influence of operating factors. HCl and H 2 SO 4 leaching systems give similar results in terms of yttrium extraction yield, but the last one allows to reduce calcium extraction with subsequent advantage during recovery of yttrium compounds in the downstream. The greatest extraction of yttrium is obtained by 20% w/v S/L ratio, 4 N H 2 SO 4 concentration and 90 deg. C. Yttrium and calcium yields are nearly 85% and 5%, respectively. The analysis of variance shows that acid concentration alone and interaction between acid and pulp density have a significant positive effect on yttrium solubilization for both HCl and H 2 SO 4 medium. Two models are empirically developed to estimate yttrium and calcium concentration during leaching. Precipitation tests demonstrate that at least the stoichiometric amount of oxalic acid is necessary to recover yttrium efficiently and a pure yttrium oxalate n-hydrate can be produced (99% grade). The process is economically feasible if other components of the fluorescent lamps (glass, ferrous and non-ferrous scraps) are recovered after the equipment dismantling and valorized, besides the cost that is usually paid

  12. Influence of scandium on the microstructure and strength properties of the welded joint at the laser welding of aluminum-lithium alloys

    Science.gov (United States)

    Malikov, A. G.; Golyshev, A. A.; Ivanova, M. Yu.

    2017-10-01

    Today, aeronautical equipment manufacture involves up-to-date high-strength aluminum alloys of decreased density resulting from lithium admixture. Various technologies of fusible welding of these alloys are being developed. Serious demands are imposed to the welded joints of aluminum alloys in respect to their strength characteristics. The paper presents experimental investigations of the optimization of the laser welding of aluminum alloys with the scandium-modified welded joint. The effect of scandium on the micro-and macro-structure has been studied as well as the strength characteristics of the welded joint. It has been found that scandium under in the laser welding process increases the welded joint elasticity for the system Al-Mg-Li, aluminum alloy 1420 by 20 %, and almost doubles the same for the system Al-Cu-Li, aluminum alloy 1441.

  13. Laboratory studies into the use of the scandium-46-EDTA complex as a tracer for groundwater flow

    International Nuclear Information System (INIS)

    Cheng, H.; Nixon, S.C.

    1988-01-01

    Gamma ray emitting metal radionuclides, when complexed with an appropriate complexing agent, provide a wide choice of water tracers particularly for groundwater studies where a radionuclide of appropriate half-life suited to the particular study can be selected. Scandium-46 has easily detectable gamma emission and a suitable half-life (84 days) for medium term studies. It has been widely and successfully used as a tracer in studies of sediment movement but has not yet been introduced as a groundwater tracer. In our experiments the chemical aspects of the preparation of Sc-46-EDTA were studied in some detail and its behaviour in various mineralogical environments was evaluated with reference to the standard tracer, tritiated water. The experimental results have shown that the scandium cation can be easily complexed with EDTA to form soluble SC-EDTA. The complex is very stable in a wide range of pH; the adsorptive properties of Sc-EDTA in the batch studies and the retardation and recovery in the column tests in comparison with tritiated water are quite satisfactory. In general Sc-46-EDTA is a promising tracer for groundwater studies. In the report the appropriate conditions, procedures and some rational and efficient methods for testing the purity of Sc-46-EDTA in the preparation of the tracer solution of Sc-46-EDTA are described. In addition, it has been found that the formation of the metal hydroxide colloids is the major reason for the great loss in groundwater aquifers of most trivalent metal nuclide tracers in the cationic form including scandium-46. (author). 29 refs, 11 figs, 12 tabs

  14. On the suitability of lanthanides as actinide analogs

    International Nuclear Information System (INIS)

    Raymond, Kenneth; Szigethy, Geza

    2008-01-01

    With the current level of actinide materials used in civilian power generation and the need for safe and efficient methods for the chemical separation of these species from their daughter products and for long-term storage requirements, a detailed understanding of actinide chemistry is of great importance. Due to the unique bonding properties of the f-elements, the lanthanides are commonly used as structural and chemical models for the actinides, but differences in the bonding between these 4f and 5f elements has become a question of immediate applicability to separations technology. This brief overview of actinide coordination chemistry in the Raymond group at UC Berkeley/LBNL examines the validity of using lanthanide analogs as structural models for the actinides, with particular attention paid to single crystal X-ray diffraction structures. Although lanthanides are commonly accepted as reasonable analogs for the actinides, these comparisons suggest the careful study of actinide materials independent of their lanthanide analogs to be of utmost importance to present and future efforts in nuclear industries. (authors)

  15. Filled buckyballs: recent developments from the endohedral metallofullerenes of lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Edelmann, F T [Magdeburg Univ. (Germany). Chemisches Inst.

    1995-05-15

    Metal-containing fullerenes - an intensively studied area of research. Recent developments in the field of endohedral metallofullerenes of lanthanides and the perspectives these results provide for the future are discussed herein. An additional theme is the specific incorporation of metal salts in carbon nanotubes, relatives of fullerenes, which Green et al. reported recently. (orig.)

  16. Lanthanide Lewis acid-mediated enantioselective conjugate radical additions.

    Science.gov (United States)

    Sibi, Mukund P; Manyem, Shankar

    2002-08-22

    [reaction: see text] Lanthanide triflates along with proline-derived ligands have been found to be efficient catalysts for enantioselective conjugate addition of nucleophilic radicals to enoates. N-Acyl oxazolidinones, when used as achiral additives, gave meaningful enhancements in the ees for the product.

  17. Lanthanide(III) Complexes with Tridentate Schiff Base Ligand ...

    African Journals Online (AJOL)

    Lanthanide complexes, hydrazino, antioxidant activity, X-ray structure. 1. Introduction ... measured using a Johnson Matthey scientific magnetic suscepti- bility balance. 2.1. .... of the ligand and that the nitrogen atom supporting this proton is not involved in the ... 4f-electrons are not involved in the coordination. These facts.

  18. Influencing fatty acid composition of yeasts by lanthanides

    Czech Academy of Sciences Publication Activity Database

    Kolouchová, I.; Sigler, Karel; Zimola, M.; Řezanka, Tomáš; Matatková, O.; Masák, J.

    2016-01-01

    Roč. 32, č. 8 (2016), s. 126 ISSN 0959-3993 R&D Projects: GA ČR GA14-00227S Institutional support: RVO:61388971 Keywords : Fatty acids * Lanthanides * Microbial lipids Subject RIV: EE - Microbiology, Virology Impact factor: 1.658, year: 2016

  19. Synthetic approaches to lanthanide complexes with tetrapyrrole type ligands

    International Nuclear Information System (INIS)

    Pushkarev, V E; Tomilova, L G; Tomilov, Yu V

    2008-01-01

    Approaches to the synthesis of single-, double- and triple-decker complexes of lanthanides with phthalocyanines and their analogues known to date are considered. Examples of preparation of sandwich-type complexes based on other metals of the Periodic system are given.

  20. Luminescent Lanthanide Reporters for High-Sensitivity Novel Bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Anstey, Mitchell R. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Fruetel, Julia A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Foster, Michael E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hayden, Carl C. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Buckley, Heather L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Arnold, John [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2013-09-01

    Biological imaging and assay technologies rely on fluorescent organic dyes as reporters for a number of interesting targets and processes. However, limitations of organic dyes such as small Stokes shifts, spectral overlap of emission signals with native biological fluorescence background, and photobleaching have all inhibited the development of highly sensitive assays. To overcome the limitations of organic dyes for bioassays, we propose to develop lanthanide-based luminescent dyes and demonstrate them for molecular reporting applications. This relatively new family of dyes was selected for their attractive spectral and chemical properties. Luminescence is imparted by the lanthanide atom and allows for relatively simple chemical structures that can be tailored to the application. The photophysical properties offer unique features such as narrow and non-overlapping emission bands, long luminescent lifetimes, and long wavelength emission, which enable significant sensitivity improvements over organic dyes through spectral and temporal gating of the luminescent signal.Growth in this field has been hindered due to the necessary advanced synthetic chemistry techniques and access to experts in biological assay development. Our strategy for the development of a new lanthanide-based fluorescent reporter system is based on chelation of the lanthanide metal center using absorbing chromophores. Our first strategy involves "Click" chemistry to develop 3-fold symmetric chelators and the other involves use of a new class of tetrapyrrole ligands called corroles. This two-pronged approach is geared towards the optimization of chromophores to enhance light output.

  1. Sol–gel preparation of selected lanthanide aluminium garnets

    Czech Academy of Sciences Publication Activity Database

    Dubnikova, N.; Garskaite, E.; Pinkas, J.; Bezdička, Petr; Beganskiene, A.; Kareiva, A.

    2010-01-01

    Roč. 55, č. 2 (2010), s. 213-219 ISSN 0928-0707 Institutional research plan: CEZ:AV0Z40320502 Keywords : lanthanide aluminium garnets * sol-gel processing Subject RIV: CA - Inorganic Chemistry Impact factor: 1.525, year: 2010

  2. Studies of lanthanide complexes by a combination of spectroscopic methods

    Czech Academy of Sciences Publication Activity Database

    Krupová, Monika; Bouř, Petr; Andrushchenko, Valery

    2015-01-01

    Roč. 22, č. 1 (2015), s. 44 ISSN 1211-5894. [Discussions in Structural Molecular Biology. Annual Meeting of the Czech Society for Structural Biology /13./. 19.03.2015-21.03.2015, Nové Hrady] Institutional support: RVO:61388963 Keywords : lanthanide complexes * chirality sensing * chirality amplification * spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry

  3. Interaction of scandium and titanium atoms with a carbon surface containing five- and seven-membered rings

    International Nuclear Information System (INIS)

    Krasnov, P. O.; Eliseeva, N. S.; Kuzubov, A. A.

    2012-01-01

    The use of carbon nanotubes coated by atoms of transition metals to store molecular hydrogen is associated with the problem of the aggregation of these atoms, which leads to the formation of metal clusters. The quantum-chemical simulation of cluster models of the carbon surface of a graphene type with scandium and titanium atoms has been performed. It has been shown that the presence of five- and seven-membered rings, in addition to six-membered rings, in these structures makes it possible to strongly suppress the processes of the migration of metal atoms over the surface, preventing their clustering.

  4. Complexometric determination of aluminium and scandium using fluorides as masking agent at low pH value

    International Nuclear Information System (INIS)

    Tikhonov, V.N.

    1978-01-01

    A complexometric method is suggested to determine Al and Sc by back titration of Bi(NO 3 ) 3 solution with xylenol orange indicator at low pH values. To increase selectivity fluoride additions were used which were masked by boron acid at the end titration point. EDTA was used as a complexing agent. Metals which create at low pH values stable complexes with EDTA undestroyed by fluoride, do not interfere with Al and Sc determination. Scandium is shown to be determined more selectively than aluminium

  5. Inner-sphere and outer-sphere complexes of yttrium(III), lanthanum (III), neodymium(III), terbium(III) and thulium(III) with halide ions in N,N-dimethylformamide

    International Nuclear Information System (INIS)

    Takahashi, Ryouta; Ishiguro, Shin-ichi

    1991-01-01

    The formation of chloro, bromo and iodo complexes of yttrium(III), and bromo and iodo complexes of lanthanum(III), neodymium(III), terbium(III) and thulium(III) has been studied by precise titration calorimetry in N,N-dimethylformamide (DMF) at 25 o C. The formation of [YCl] 2+ , [YCl 2 ] + , [YCl 3 ] and [YCl 4 ] - , and [MBr] 2+ and [MBr 2 ] + (M = Y, La, Nd, Tb, Tm) was revealed, and their formation constants, enthalpies and entropies were determined. It is found that the formation enthalpies change in the sequence ΔH o (Cl) > ΔH o (l), which is unusual for hard metal (III) ions. This implies that, unlike the chloride ion, the bromide ion forms outer-sphere complexes with the lanthanide(III) and yttrium(III) ions in DMF. Evidence for either an inner- or outer-sphere complex was obtained from 89 Y NMR spectra for Y(ClO 4 ) 3 , YCl 3 and YBr 3 DMF solutions at room temperature. (author)

  6. r-PROCESS LANTHANIDE PRODUCTION AND HEATING RATES IN KILONOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Lippuner, Jonas; Roberts, Luke F., E-mail: jlippuner@tapir.caltech.edu [TAPIR, Walter Burke Institute for Theoretical Physics, California Institute of Technology, MC 350-17, 1200 E California Boulevard, Pasadena CA 91125 (United States)

    2015-12-20

    r-process nucleosynthesis in material ejected during neutron star mergers may lead to radioactively powered transients called kilonovae. The timescale and peak luminosity of these transients depend on the composition of the ejecta, which determines the local heating rate from nuclear decays and the opacity. Kasen et al. and Tanaka and Hotokezaka pointed out that lanthanides can drastically increase the opacity in these outflows. We use the new general-purpose nuclear reaction network SkyNet to carry out a parameter study of r-process nucleosynthesis for a range of initial electron fractions Y{sub e}, initial specific entropies s, and expansion timescales τ. We find that the ejecta is lanthanide-free for Y{sub e} ≳ 0.22−0.30, depending on s and τ. The heating rate is insensitive to s and τ, but certain, larger values of Y{sub e} lead to reduced heating rates, due to individual nuclides dominating the heating. We calculate approximate light curves with a simplified gray radiative transport scheme. The light curves peak at about a day (week) in the lanthanide-free (-rich) cases. The heating rate does not change much as the ejecta becomes lanthanide-free with increasing Y{sub e}, but the light-curve peak becomes about an order of magnitude brighter because it peaks much earlier when the heating rate is larger. We also provide parametric fits for the heating rates between 0.1 and 100 days, and we provide a simple fit in Y{sub e}, s, and τ to estimate whether or not the ejecta is lanthanide-rich.

  7. r-PROCESS LANTHANIDE PRODUCTION AND HEATING RATES IN KILONOVAE

    International Nuclear Information System (INIS)

    Lippuner, Jonas; Roberts, Luke F.

    2015-01-01

    r-process nucleosynthesis in material ejected during neutron star mergers may lead to radioactively powered transients called kilonovae. The timescale and peak luminosity of these transients depend on the composition of the ejecta, which determines the local heating rate from nuclear decays and the opacity. Kasen et al. and Tanaka and Hotokezaka pointed out that lanthanides can drastically increase the opacity in these outflows. We use the new general-purpose nuclear reaction network SkyNet to carry out a parameter study of r-process nucleosynthesis for a range of initial electron fractions Y e , initial specific entropies s, and expansion timescales τ. We find that the ejecta is lanthanide-free for Y e ≳ 0.22−0.30, depending on s and τ. The heating rate is insensitive to s and τ, but certain, larger values of Y e lead to reduced heating rates, due to individual nuclides dominating the heating. We calculate approximate light curves with a simplified gray radiative transport scheme. The light curves peak at about a day (week) in the lanthanide-free (-rich) cases. The heating rate does not change much as the ejecta becomes lanthanide-free with increasing Y e , but the light-curve peak becomes about an order of magnitude brighter because it peaks much earlier when the heating rate is larger. We also provide parametric fits for the heating rates between 0.1 and 100 days, and we provide a simple fit in Y e , s, and τ to estimate whether or not the ejecta is lanthanide-rich

  8. Lanthanide co-ordination frameworks: Opportunities and diversity

    International Nuclear Information System (INIS)

    Hill, Robert J.; Long, De-Liang; Hubberstey, Peter; Schroeder, Martin; Champness, Neil R.

    2005-01-01

    Significant successes have been made over recent years in preparing co-ordination framework polymers that show macroscopic material properties, but in the vast majority of cases this has been achieved with d-block metal-based systems. Lanthanide co-ordination frameworks also offer attractive properties in terms of their potential applications as luminescent, non-linear optical and porous materials. However, lanthanide-based systems have been far less studied to date than their d-block counterparts. One possible reason for this is that the co-ordination spheres of lanthanide cations are more difficult to control and, in the absence of design strategies for lanthanide co-ordination frameworks, it is significantly more difficult to target materials with specific properties. However, this article highlights some of the exciting possibilities that have emerged from the earliest investigations in this field with new topological families of compounds being discovered from relatively simple framework components, including unusual eight, seven and five-connected framework systems. Our own research, as well as others, is leading to a much greater appreciation of the factors that control framework formation and the resultant observed topologies of these polymers. As this understanding develops targeting particular framework types will become more straightforward and the development of designed polyfunctional materials more accessible. Thus, it can be seen that lanthanide co-ordination frameworks have the potential to open up previously unexplored directions for materials chemistry. This article focuses on the underlying concepts for the construction of these enticing and potentially highly important materials

  9. Thermoanalytical study of the formation mechanism of yttria from yttrium acetate

    International Nuclear Information System (INIS)

    Farjas, J.; Camps, J.; Roura, P.; Ricart, S.; Puig, T.; Obradors, X.

    2011-01-01

    Highlights: → Thermal decomposition of yttrium acetate: three endothermic stages. → Intermediates: yttrium hydroxide and carbonate. → Product: cubic yttria (the degree of transformation is at least 99%). → The decomposition does not depend on the oxygen partial pressure. - Abstract: The processes involved in the thermal decomposition of yttrium acetate tetrahydrate, Y(CH 3 COO) 3 .4H 2 O, in air and in an inert atmosphere have been analyzed by thermoanalytical techniques (thermogravimetry, differential thermal analysis and evolved gas analysis) and by the structural characterization (X-ray diffraction, infrared spectroscopy, elemental analysis and scanning electron microscopy) of intermediates and final products. Decomposition of yttrium acetate is an endothermic transformation that takes place in a temperature range between 350 and 900 o C. The evolution of the mass during the decomposition process is not affected by the presence of oxygen. The process is initiated by the rupture of the bond between the metallic cation and the acetate ligand. This initial step (350-450 o C) involves the formation of amorphous yttrium hydroxide and yttrium carbonate and is characterized by a fast mass loss rate. A sudden decrease of the mass loss rate indicates a change in the decomposition kinetics that continues with the decomposition of yttrium hydroxide and yttrium carbonate. The main effect of an oxygen atmosphere is an intense exothermic process due to the combustion of organic species in the gas phase.

  10. Yttrium implantation and addition element effects on the oxidation behaviour of reference steels at 973 K

    Energy Technology Data Exchange (ETDEWEB)

    Caudron, E.; Buscail, H.; Cueff, R.; Issartel, C.; El Messki, S.; Perrier, S.; Riffard, F. [Lab. Vellave d' Elaboration et d' Etude des Materiaux, Univ. Blaise Pascal Clermont-Fd 2, Le Puy en Velay (France)

    2004-07-01

    Yttrium implantation effects on reference steels (extra low carbon and low manganese steel) were studied by rutherford backscattering spectrometry (RBS), reflection high energy electron diffraction (RHEED), X-ray diffraction (XRD) and glancing angle X-ray diffraction (GAXRD). Thermogravimetry and in situ X-ray diffraction at 700 C and P{sub O2}=0.04 Pa for 24h were used to determine the yttrium implantation and addition element effects on sample oxidation resistance at high temperatures. This study clearly shows that yttrium implantation and subsequent high temperature oxidation induced the formation of several yttrium mixed oxides which closely depend on the reference steel addition elements. Moreover, these yttrium mixed oxides seem to be responsible for the improved reference steel oxidation resistance at high temperatures. (orig.)

  11. Tattoo removal by Q-switched yttrium aluminium garnet laser

    DEFF Research Database (Denmark)

    Hutton Carlsen, K; Esmann, J; Serup, J

    2017-01-01

    BACKGROUND: Tattoo removal by Q-switched yttrium aluminium garnet (YAG) lasers is golden standard; however, clients' satisfaction with treatment is little known. OBJECTIVE: To determine clients' satisfaction with tattoo removal. METHODS: One hundred and fifty-four tattoo removal clients who had...... relative to colour of tattoo on a scale from 0 (no effect) to 10 (complete removal) scored a mean of blue 9.5, black 9.4, yellow 8.9, red 8.8 and green 6.5. Clients were dissatisfied with green pigment remnants, which could mimic bruising. One hundred and twenty-nine clients (84%) experienced moderate...

  12. Phase composition of yttrium-doped zirconia ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Hennig, Christoph; Scheinost, Andreas C. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Molecular Structures; Weiss, Stephan [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes; Ikeda-Ohno, Atsushi [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Chemistry of the F-Elements; Gumeniuk, R. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Experimentelle Physik

    2017-06-01

    Ceramic material might be an alternative to borosilicate glass for the immobilization of nuclear waste. The crystallinity of ceramic material increases the corrosion resistance over several magnitudes in relation to amorphous glasses. The stability of such ceramics depend on several parameters, among them the crystal phase composition. A reliable quantitative phase analysis is necessary to correlate the macroscopic material properties with structure parameters. We performed a feasibility study based on yttrium-doped zirconia ceramics as analogue for trivalent actinides to ascertain that the nanosized crystal phases in zirconia ceramics can be reliably determined.

  13. Structure-terahertz property relationship in yttrium aluminum garnet ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Steere, D.W.; Clark, B.M.; Sundaram, S.K. [Alfred University, Terahertz and Millimeter Waves Laboratory (T-Lab), Kazuo Inamori School of Engineering, The New York State College of Ceramics, Alfred, NY (United States); Gaume, R. [Townes Laser Institute and the NanoScience Technology Center, CREOL, The College of Optics and Photonics, Orlando, FL (United States)

    2017-08-15

    Terahertz (THz) transmission measurements on chemically variant yttrium aluminum garnet (YAG) ceramics are described. Chemical compositions and processing parameters were varied to determine the effect of stoichiometry, density, and pore volume distribution on the optical and dielectric properties in the THz frequency regime. Density has the largest effect on properties out of the parameters that were investigated. In addition, a linear correlation between cubic root of real permittivity at 1 THz and average density of these samples is observed. Our results show promise for design and fabrication of advanced optical materials and devices with desired THz properties via controlling density and porosity of the materials. (orig.)

  14. Optical properties of Dy3+ doped yttrium aluminium borate

    International Nuclear Information System (INIS)

    Vazquez, R MartInez; Osellame, R; Marangoni, M; Ramponi, R; Dieguez, E; Ferrari, M; Mattarelli, M

    2004-01-01

    A Dy 3+ doped yttrium aluminium borate (Dy:YAB) crystal has been optically characterized. The refractive indices at seven different wavelengths, ranging from the visible to the near infrared (IR), have been measured and the Sellmeier curves have been calculated. The polarized optical absorption spectra have been obtained at room temperature, and the Judd-Ofelt parameters have been calculated. The lifetime of the upper laser level 4 F 9/2 has been estimated and compared with the experimental value. Evidence of high luminescence quantum efficiency of the 4 F 9/2 state in YAB is provided by measured lifetimes

  15. Kinetic properties of solid yttrium at high temperatures

    International Nuclear Information System (INIS)

    Ivliev, A.D.

    1993-01-01

    Analysis of results of experimental investigation into temperature-diffusivity, specific electroresistance and heat conductivity of yttrium is carried out. Peculiarities of variation of its kinetic characteristics under high temperatures are shown to result from two-band character of energy spectrum of collectivized electrons. In particular, growth of heat conductivity results from reduction of density of heavy electron states under heating. The suggested model describes kinetic characteristics of lutetium, as well. Usage of this model for the rest heavy rare-earth metals enables to make conclusion about reduction of magnetic scattering effcieincy in the rare-earth metals in proportion to approximation to melting temperature

  16. Knee arthroscopy after yttrium or osmic acid injection

    International Nuclear Information System (INIS)

    Guaydier-Souquieres, C.; Beguin, J.; Ollivier, D.; Loyau, G.

    1989-01-01

    This study presents the macroscopic and histologic results of 35 knee arthroscopies performed on patients with rheumatoid arthritis, some months after an yttrium or osmic acid intraarticular injection. The procedure was most often performed after a failure of the injection or a relapse of synovitis. Arthroscopy provides an understanding of the cause of synoviorthesis failure--insufficient action of the product on the synovitis or its poor diffusion, fibri-nonecrotic deposits, or cartilaginous lesions--and may be used both diagnostically and therapeutically

  17. Spectrographic determination of strontium in yttrium-90 solutions

    International Nuclear Information System (INIS)

    Roca, M.; Capdevila, C.

    1970-01-01

    The copper spark method has been used for determining strontium in the concentration range 1-100 g/ml in yttrium-90 solutions containing 0,5 % or thereabouts of ammonium citrate. The influence of the citric acid as well as the ammonium citrate with regard to 2N HCL solutions has been studied: the citric acid enhances the line intensities of strontium. The employment of either barium or lanthanum as reference element compensates for this enhancement. Because of the increase in sensitivity mentioned above, the study of influence of the citric acid has been extended and several impurities usually determined in radioisotope solutions have been considered. (Author) 4 refs

  18. Scattering of polarized protons by yttrium, iron and nickel nuclei

    International Nuclear Information System (INIS)

    Melssen, J.P.M.G.

    1978-01-01

    Results are presented of scattering experiments performed on yttrium and some iron and nickel isotopes with polarized proton beams at energies around 20 MeV. The angular distributions of the differential cross sections and analyzing powers have been measured and comparison of these with predictions from theoretical models has led to information about excited nuclear states like spin, parity and details of the wavefunctions. The DWBA has been mostly used to describe the reaction at the bombarding energies and for the target nuclei investigated. (C.F.)

  19. Childhood acromegaly successfully treated with interstitial irradiation using Yttrium-90

    International Nuclear Information System (INIS)

    Rosenstock, J.; Doyle, F.H.; Mashiter, K.; Joplin, G.F.

    1982-01-01

    A child with a growth hormone producing tumour presented at the age of 4 1/2 years. The onset of the disease was at 18 months of age. Treatment was given with three doses of interstitial irradiation using yttrium-90 implants. There were no local complications from the procedures. Now, 11 years after diagnosis, she is asymptomatic, of normal appearance, and her height and the size of the pituitary fossa are normal. Growth hormone levels are almost normal, thyroid function is intact, and she is maintained on prednisone and sex hormones. (Authors)

  20. Childhood acromegaly successfully treated with interstitial irradiation using Yttrium-90

    Energy Technology Data Exchange (ETDEWEB)

    Rosenstock, J.; Doyle, F.H.; Mashiter, K.; Joplin, G.F. (Royal Postgraduate Medical School, Hammersmith Hospital, London (UK). Dept. of Medicine and Radiology); Hall, R. (Royal Victoria Infirmary, Newcastle upon Tyne (UK))

    1982-01-01

    A child with a growth hormone producing tumour presented at the age of 4 1/2 years. The onset of the disease was at 18 months of age. Treatment was given with three doses of interstitial irradiation using Yttrium-90 implants. There were no local complications from the procedures. Now, 11 years after diagnosis, she is asymptomatic, of normal appearance, and her height and the size of the pituitary fossa are normal. Growth hormone levels are almost normal, thyroid function is intact, and she is maintained on prednisone and sex hormones.

  1. Photometric determination of yttrium in zirconium-containing materials

    International Nuclear Information System (INIS)

    Barbina, T.M.; Polezhaev, Yu.M.

    1984-01-01

    Comparative evaluation of the effect of different ways of eliminating the zirconium interfering effect on the results of yttrium photometric determination with arsenazo 2 in artificial mixtures of Y 2 O 3 and ZrO 2 , containing 5 and 10 mol.% Y 2 O 3 , has been carried out. The effect of Zr is eliminated by means of its precipitation by ammonium solution in the form of hydroxide and using camouflaging with 25% sulfosalicylic acid. Both ways do not provide a correct enough result. The use of non-reagent thermohydrolytic Zr precipitation during the analysis of zirconium-containing materials permits to obtain correct and well-reproducible results

  2. Thiocarbomide coordination compounds of yttrium subgroup rare earth chlorides

    International Nuclear Information System (INIS)

    Sakharova, Yu.G.; Perov, V.N.; Loginov, V.I.

    1978-01-01

    Thiocarbamide coordination compounds of chlorides of elements of the yttrium subgroup 4MeCl 3 x5Cs(NH 2 ) 2 x2OH 2 O (where Me stands for Tb, Dy, Ho, Er, Tm, Yb, Lu, Y) were produced for the first time. The compounds obtained are stable in air, have definite melting points, are highly soluble in methyl and ethyl alcohols, and are unstable in water. They recrystallize from ethyl alcohol without changing their chemical composition. The identity of these compounds was confirmed by X-ray analysis

  3. Magnetic susceptibility of scandium-hydrogen and lutetium-hydrogen solid-solution alloys from 2 to 3000K

    International Nuclear Information System (INIS)

    Stierman, R.J.

    1982-12-01

    Results for pure Sc show that the maximum and minimum in the susceptibility discovered earlier are enhanced as the impurity level of iron in scandium decreases. The Stoner enhancement factor, calculated from low-temperature heat capacity data, susceptibility data, and band-structure calculations show Sc to be a strongly enhanced paramagnet. Below 2 0 K, the magnetic anisotropy between the hard and easy directions of scandium decreases linearly with decreasing temperature, tending toward zero at 0 K. The large increase in the susceptibility of Sc at lower temperatures indicates magnetic ordering. Pure Lu and Lu-H alloys showed an anisotropy in susceptibility vs orientation; thus the samples were not random polycrystalline samples. Pure Lu shows the shallow maximum and minimum, but the increase in susceptibility at low temperatures is larger than previously observed. The susceptibility-composition dependence of the Lu-H alloys also did not match other data. The susceptibility-composition dependence does not match the composition dependence of the electronic specific heat constant below 150 K, showing the electronic specific heat is being affected by terms other than phonon-electron and pure electron-electron interactions

  4. Adsorption behaviors of trivalent actinides and lanthanides on pyridine resin in lithium chloride aqueous solution

    International Nuclear Information System (INIS)

    Tatsuya Suzuki

    2013-01-01

    The adsorption behaviors of trivalent actinides and lanthanides on pyridine resin in lithium chloride aqueous solution were investigated. The adsorbed amounts of lanthanides and the degree of mutual separation of lanthanides increased with an increase in the concentration of lithium chloride in aqueous solution. The group separation of the trivalent actinides and lanthanides was observed. This separation phenomenon is similar in a hydrochloric acid solution. However, the adsorption behavior of lanthanides in lithium chloride is different from their behavior in a hydrochloric acid solution. This fact shows that the adsorption mechanisms of lanthanides in a lithium chloride aqueous solution and in a hydrochloric acid solution are different; the adsorption mechanisms are attributed to the ion exchange in a hydrochloric acid solution, and to the complex formation with pyridine group in a lithium chloride solution. (author)

  5. Luminescent hybrid lanthanide sulfates and lanthanide sulfonate-carboxylates with 1,10-phenanthroline involving in-situ oxidation of 2-mercaptonbenzoic acid

    International Nuclear Information System (INIS)

    Zhong, Jie-Cen; Wan, Fang; Sun, Yan-Qiong; Chen, Yi-Ping

    2015-01-01

    A series of lanthanide sulfates and lanthanide sulfonate-carboxylates, [Ln 2 (phen) 2 (SO 4 ) 3 (H 2 O) 2 ] n (I:Ln=Nd(1a), Sm(1b), Eu(1c), phen=1,10-phenanthroline) and [Ln(phen)(2-SBA)(BZA)] n (II: Ln=Sm(2a), Eu(2b), Dy(2c), 2-SBA=2-sulfobenzoate, BZA=benzoate) have been hydrothermally synthesized from lanthanide oxide, 2-mercaptonbenzoic acid with phen as auxiliary ligand and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, TG analyses and luminescence spectroscopy. Interestingly, SO 4 2− anions in I came from the in situ deep oxidation of thiol groups of 2-mercaptonbenzoic acid while 2-sulfobenzoate and benzoate ligands in II from the middle oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. Compounds I are organic–inorganic hybrid lanthanide sulfates, which have rare one-dimensional column-like structures. Complexes II are binuclear lanthanide sulfonate-carboxylates with 2-sulfobenzoate and benzoate as bridges and 1,10-phenanthroline as terminal. Photoluminescence studies reveal that complexes I and II exhibit strong lanthanide characteristic emission bands in the solid state at room temperature. - Graphical abstract: Lanthanide sulfates and lanthanide sulfonate-carboxylates have been hydrothermally synthesized. Interestingly, sulfate anions, 2-sulfobenzoate and benzoate ligands came from the in situ oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. - Highlights: • In situ oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. • The organic–inorganic hybrid lanthanide sulfates with one-dimensional column-like structure. • The dinuclear lanthanide sulfonate-carboxylates. • The emission spectra exhibit the characteristic transition of 5 D 0 → 7 F J (J=0–4) of the Eu(III)

  6. Structural characterization of hydrogen separating membranes based on lanthanide-tungstates

    International Nuclear Information System (INIS)

    Scherb, Tobias

    2011-01-01

    The global energy supply is currently the most controversial issue discussed in our society. Despite the increasing importance of renewable energies, the largest portion of electrical energy has its origin in fossil fuels. CO 2 , emitted during combustion in power plants is known to be one of the greenhouse gases that contributes significantly to global climate change. The development of technologies for environmentally friendly power generation from coal and gas is an area of significant interest. One possibility is the capture and long-term storage of CO 2 from the exhaust stream of fossil fuel power plants. In the pre-combustion process, CO 2 and H 2 can be separated after gasification of the fossil fuel. For this purpose gas-tight ceramic membranes with mixed electronic-protonic conductivity can be used. However, these materials have high requirements due to the extreme conditions in power plants. Mixed electronic-protonic conducting lanthanide tungstates (Ln 6 WO 12 Ln = lanthanide or yttrium) are promising materials, which are stable in CO 2 -containing harsh environments. This work presents a study on structure-property relationships of Ln 6 WO 12 . The structural analysis was performed by the use of neutron and high-resolution X-ray diffraction methods for three exemplary systems (Ln = La, Nd, Y). Samples were prepared via solid state reaction (SSR), and also via a sol-gel approach (Pechini). For the systems LaWO and NdWO, new structural models were developed by combined Rietveld analysis and Fourier density maps. The latter was applied to determine the electron and nuclear density distribution. LaWO with a La/W ratio from 5.3 to 5.7 crystallizes with the space group F-43m and forms a superstructure due to a partially ordered arrangement of cations. On Wyckoff site 48h, up to 4.6 % W can be substituted by La. The oxygen atoms around tungsten are highly delocalized and 6 out of 24 possible split positions are occupied. Thus, W has an octahedral coordination

  7. Highly Luminescent, Water-Soluble Lanthanide Fluorobenzoates: Syntheses, Structures and Photophysics, Part I: Lanthanide Pentafluorobenzoates.

    Science.gov (United States)

    Kalyakina, Alena S; Utochnikova, Valentina V; Bushmarinov, Ivan S; Ananyev, Ivan V; Eremenko, Igor L; Volz, Daniel; Rönicke, Franziska; Schepers, Ute; Van Deun, Rik; Trigub, Alexander L; Zubavichus, Yan V; Kuzmina, Natalia P; Bräse, Stefan

    2015-12-01

    Highly luminescent, photostable, and soluble lanthanide pentafluorobenzoates have been synthesized and thoroughly characterized, with a focus on Eu(III) and Tb(III) complexes as visible emitters and Nd(III) , Er(III) , and Yb(III) complexes as infrared emitters. Investigation of the crystal structures of the complexes in powder form and as single crystals by using X-ray diffraction revealed five different structural types, including monomeric, dimeric, and polymeric. The local structure in different solutions was studied by using X-ray absorption spectroscopy. The photoluminescence quantum yields (PLQYs) of terbium and europium complexes were 39 and 15 %, respectively; the latter value was increased almost twice by using the heterometallic complex [Tb0.5 Eu0.5 (pfb)3 (H2 O)] (Hpfb=pentafluorobenzoic acid). Due to the effectively utilized sensitization strategy (pfb)(-) →Tb→Eu, a pure europium luminescence with a PLQY of 29 % was achieved. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. The spectroscopy and structure of some lanthanide chlorides in amide solutions

    International Nuclear Information System (INIS)

    Legendziewicz, J.; Bukietynska, K; Jezowsky-Trzebiatowska, B.

    1974-01-01

    The absorption spectra of Pr, Nd, Ho, and Er anhydrous and hydrated chlorides in formamide, methyl-, dimethyl-, and diethylformamide solutions have been investigated in the range of 8000 - 4200 cm -1 . By the Judd-Oefelt method of intensity analysis and by calculating the nepheloauxetic effect, the first coordination sphere of lanthanide ions and the approximate symmetry of amide solvates of anhydrous and hydrated lanthanide chlorides were determined. A difference between symmetry and coordination numbers for light and heavy lanthanide solvates has been found. Some considerations regarding the structure of lanthanide solvates and structure of amide molecules have been made. (B.T.)

  9. Lanthanide Selective Sorbents: Self-Assembled Monolayers on Mesoporous Supports (SAMMS)

    Energy Technology Data Exchange (ETDEWEB)

    Fryxell, Glen E.; Wu, Hong; Lin, Yuehe; Shaw, Wendy J.; Birnbaum, Jerome C.; Linehan, John C.; Nie, Zimin; Kemner, Kenneth M.; Kelly, Shelley

    2004-11-01

    Through the marriage of mesoporous ceramics with self-assembled monolayer chemistry, the genesis of a powerful new class of environmental sorbent materials has been realized. By coating the mesoporous ceramic backbone with a monolayer terminated with a lanthanide-specific ligand, it is possible to couple high lanthanide binding affinity with the high loading capacity (resulting from the extremely high surface area of the support). This lanthanide-specific ligand field is created by pairing a “hard” anionic Lewis base with a suitable synergistic ligand, in a favorable chelating geometry. Details of the synthesis, characterization, lanthanide binding studies, binding kinetics, competition experiments and sorbent regeneration studies are summarized.

  10. Behaviour of trivalent actinides and lanthanide elements in chloride solution; Comportement des lanthanides et transuraniens trivalents en milieu chlorhydrique

    Energy Technology Data Exchange (ETDEWEB)

    Marin, B [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    The aim of this work is to compare the complexation in chloride solutions of trivalent lanthanides and actinides. We have first studied the solvatation of these cations without complexation. We found a difference between Am, Cm and Rare Earths (we can separate lanthanides into Light and Heavy Rare Earths). For studying the complexation we choose the technic of electrophoresis on paper after establishing a simple theory of mobilities in complex solutions. The hydrolysis of these cations was studied and compared in chloride solutions. We have then studied the complexation with the Cl{sup -} ligand in some solutions: HCl, NH{sub 4}Cl, CaCl{sub 2}, CeCl{sub 3}, LiCl. We have established that the complexation is the same in dilute HCl solutions but in concentrated solutions the trivalent actinides are more complexed. This difference is sharper in LiCl solutions. We also proposed the different models of complex in these solutions. (author) [French] Le but de ce travail est de comparer les transuraniens et lanthanides trivalents au point de vue de leur complexation en solution chlorhydrique. Nous avons ete amenes tout d'abord a etudier la solvatation de ces cations non complexes. C'est ainsi que nous pouvons constater une difference entre Am, Cm et les lanthanides. Ces derniers pouvant se separer en lanthanides legers et lanthanides lourds. Pour etudier la complexation nous avons utilise l'electrophorese sur papier apres avoir donne une theorie simple des mobilites en milieu complexant. Apres avoir etudie et compare l'hydrolyse de ces divers cations en solution chlorhydrique, nous avons etudie leur complexation avec l'ion Cl{sup -} dans dans divers milieux: HCl, NH{sub 4}Cl, CaCl{sub 2}, CeCl{sub 3}, LiCl. ous avons note qu'en solution HCl les deux series se comportent de la meme facon pour des concentrations faibles en Cl{sup -} mais que les transuraniens se complexent plus fortement dans les solutions concentrees. Cette difference s'accroit encore dans les milieux

  11. Hydrogen sensor based on palladium-yttrium alloy nanosheet

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Boyi [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia); Zhu, Yong, E-mail: y.zhu@griffith.edu.au [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia); Chen, Youping; Song, Han; Huang, Pengcheng [School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074 (China); Dao, Dzung Viet [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia)

    2017-06-15

    This paper presents a hydrogen sensor based on palladium-yttrium (Pd-Y) alloy nanosheet. Zigzag-shaped Pd-Y nanosheet with a thickness of 19.3 nm was deposited on a quartz substrate by using an ultrahigh-vacuum magnetron sputtering system and shadow mask. The atomic ratio of palladium to yttrium in the nanosheet was 0.92/0.08. The fabrication process was simple and low-cost, and the sensor can be mass-produced. The experimental results show the sensor has a superior sensitivity, reversibility, and reproducibility. The resistive-based hydrogen detection mechanism in this research is much simpler and more compact compared to the optical-based detection method. - Highlights: • Pd-Y sensing element was fabricated using a magnetron sputtering system and shadow mask. • The Pd-Y compound consisted of 92% Pd and 8% Y. • The fabrication process was simple, low-cost, and mass-production compatible. • The sensor showed superior sensitivity, reversibility, and reproducibility to hydrogen gas. • The device is more compact than the optical-based counterpart.

  12. Yttrium ion implantation on the surface properties of magnesium

    International Nuclear Information System (INIS)

    Wang, X.M.; Zeng, X.Q.; Wu, G.S.; Yao, S.S.

    2006-01-01

    Owing to their excellent physical and mechanical properties, magnesium and its alloys are receiving more attention. However, their application has been limited to the high reactivity and the poor corrosion resistance. The aim of the study was to investigate the beneficial effects of ion-implanted yttrium using a MEVVA ion implanter on the surface properties of pure magnesium. Isothermal oxidation tests in pure O 2 at 673 and 773 K up to 90 min indicated that the oxidation resistance of magnesium had been significantly improved. Surface morphology of the oxide scale was analyzed using scanning electron microscope (SEM). Auger electron spectroscopy (AES) and X-ray diffraction (XRD) analyses indicated that the implanted layer was mainly composed of MgO and Y 2 O 3 , and the implanted layer with a duplex structure could decrease the inward diffusion of oxygen and reduce the outward diffusion of Mg 2+ , which led to improving the oxidation resistance of magnesium. Potentiodynamic polarization curves were used to evaluate the corrosion resistance of the implanted magnesium. The results show yttrium implantation could enhance the corrosion resistance of implanted magnesium compared with that of pure magnesium

  13. Hydrogen sensor based on palladium-yttrium alloy nanosheet

    International Nuclear Information System (INIS)

    Wang, Boyi; Zhu, Yong; Chen, Youping; Song, Han; Huang, Pengcheng; Dao, Dzung Viet

    2017-01-01

    This paper presents a hydrogen sensor based on palladium-yttrium (Pd-Y) alloy nanosheet. Zigzag-shaped Pd-Y nanosheet with a thickness of 19.3 nm was deposited on a quartz substrate by using an ultrahigh-vacuum magnetron sputtering system and shadow mask. The atomic ratio of palladium to yttrium in the nanosheet was 0.92/0.08. The fabrication process was simple and low-cost, and the sensor can be mass-produced. The experimental results show the sensor has a superior sensitivity, reversibility, and reproducibility. The resistive-based hydrogen detection mechanism in this research is much simpler and more compact compared to the optical-based detection method. - Highlights: • Pd-Y sensing element was fabricated using a magnetron sputtering system and shadow mask. • The Pd-Y compound consisted of 92% Pd and 8% Y. • The fabrication process was simple, low-cost, and mass-production compatible. • The sensor showed superior sensitivity, reversibility, and reproducibility to hydrogen gas. • The device is more compact than the optical-based counterpart.

  14. Effects of hepatic arterial yttrium 90 glass microspheres in dogs.

    Science.gov (United States)

    Wollner, I; Knutsen, C; Smith, P; Prieskorn, D; Chrisp, C; Andrews, J; Juni, J; Warber, S; Klevering, J; Crudup, J

    1988-04-01

    A 22-micron glass microsphere called TheraSphere (Theragenics Corp., Atlanta, GA) has been developed in which yttrium 89 oxide is incorporated into the glass matrix and is activated by neutron bombardment to form the beta-emitting isotope yttrium 90 (Y 90) before using the spheres as radiotherapeutic vehicles. The injection of up to 12 times (on a liver weight basis) the anticipated human dose of nonradioactive TheraSphere into the hepatic arteries of dogs was well tolerated and produced clinically silent alterations within centrolobular areas. The hepatic arterial (HA) injection of radioactive TheraSphere also produced portal changes similar to those observed in humans after external beam therapy. While the extent of damage increased with the delivered dose, radiation exposures in excess of 30,000 cGy did not cause total hepatic necrosis and were compatible with survival. No microspheres distributed to the bone marrow and absolutely no myelosuppression was encountered in any animal. Proposed hepatic exposures to humans of 5000 to 10,000 cGy by means of these microspheres, therefore, would appear to be feasible and tolerable. Radiotherapeutic microsphere administration preceded by regional infusion of a radiosensitizing agent and/or immediately following the redistribution of blood flow toward intrahepatic tumor by vasoactive agents can potentially yield a synergistic, highly selective attack on tumors confined to the liver.

  15. MCrAlY bond coat with enhanced Yttrium layer

    Science.gov (United States)

    Jablonski, Paul D; Hawk, Jeffrey A

    2015-04-21

    One or more embodiments relates to an MCrAlY bond coat comprising an MCrAlY layer in contact with a Y--Al.sub.2O.sub.3 layer. The MCrAlY layer is comprised of a .gamma.-M solid solution, a .beta.-MAl intermetallic phase, and Y-type intermetallics. The Y--Al.sub.2O.sub.3 layer is comprised of Yttrium atoms coordinated with oxygen atoms comprising the Al.sub.2O.sub.3 lattice. Both the MCrAlY layer and the Y--Al.sub.2O.sub.3 layer have a substantial absence of Y--Al oxides, providing advantage in the maintainability of the Yttrium reservoir within the MCrAlY bulk. The MCrAlY bond coat may be fabricated through application of a Y.sub.2O.sub.3 paste to an MCrAlY material, followed by heating in a non-oxidizing environment.

  16. Effect of vanadium and yttrium doping on BSCCO superconductors

    International Nuclear Information System (INIS)

    Mohamed, S.B.; Halim, S.A.; Azhan, H.; Sidek, H.A.A; Tee, T.W.; Hassan, Z.A.

    1999-01-01

    The effect of vanadium and yttrium doping on the superconductivity is investigated. The doping was done on the calcium site ranging from x=0.00-0.10. The temperature dependence of electrical resistance and AC susceptibility measurements were made on these samples. The zero resistance for vanadium doped samples varied from 107 K (x = 0.00) to 68.5K (x = 0.10), whereas for yttrium doped samples it varied from 107 K (x = 0.00) to 54K (x 0.10). The volume fraction of the 2223 phase for both dopalit decreases witli increasing doping concentration. The nature of the temperature derivative of the resistance curves indicates the presence of a superconducting transition between grains coupled by weak links. The AC susceptibility data show enrichment of the volume fraction of the low Tc phase at higher compositions. The presence of low Tc phase (∼70 K) is visible in the susceptibility data. X-ray diffraction confirms the presence of mixed phases in the samples. (author)

  17. Superconductivity in the lanthanum-yttrium-manganese alloy system

    International Nuclear Information System (INIS)

    Stierman, R.J.

    1980-03-01

    An empirical approach involving lattice instabilities was investigated in the search for new superconducting materials. Pseudo-lanthanide compounds using La and Y were prepared for the system La/sub 1-x/Y/sub x/Mn 2 by arc melting and subsequent heat treatment. Low temperature magnetic susceptibility and low temperature heat capacity measurements were made. The unit cell lattice parameters were determined from x-ray powder patterns taken on most samples and metallographic examination was carried out on selected samples. Alloys with low La concentrations (x greater than or equal to 0.6) showed RMn 2 in the cubic C15 Laves phase as the major component with second phase material present. The magnetic susceptibility and x-ray data indicated a superconducting phase which seemed to be the RMn 2 phase, but heat capacity measurements showed the second phase material was the superconductor, while the RMn 2 was not. Failure to form compounds with higher La content was experienced and may be due to the lattice instability expected at x = 0.56. This indicates that perhaps more stingent conditions are required to form pseudo-lanthanide compounds than were previously considered. More systems should be investigated to see if this is true, and to determine the possibilities of this approach

  18. Organometallic complex chemistry of plutonium and selected lanthanides

    International Nuclear Information System (INIS)

    Seemann, U.

    1987-01-01

    This study deals with the metallo-organic chemistry of plutonium and also with that of some lanthanides. For plutonium, the conversion of Cs 2 PuCl 6 with four equivalents KCp is investigated. In the series Sm, Gd, Dy and Er, compounds of the type Cp 2 LnX and the base adducts with acetonitrile are analysed. The ligand X passes the series Cl, N 3 , NCS and NCO. Both, the thermal and the vibrational spectroscopic behaviour is investigated. In addition, the effect of a changed ligand sphere on the optical spectrum is discussed. The adduct-free compounds are described by a ternary reaction not yet known from literature. For the first time, force constant calculations are carried out on metallo-organic compounds of lanthanides. With the exception of Cp 2 LnCl compounds, all compouds are presented for the first time in the framework of this study. (orig.) [de

  19. Optical Properties of Lanthanides in Condensed Phase, Theory and Applications

    Directory of Open Access Journals (Sweden)

    Renata Reisfeld

    2015-04-01

    Full Text Available The basic theories of electronic levels and transition probabilities of lanthanides are summarized. Their interpretation allows practical preparation of new materials having application in lighting, solar energy utilization, optoelectronics, biological sensors, active waveguides and highly sensitive bioassays for in vitro detection in medical applications. The ways by which the weak fluorescence arising from electronic transition within the four f-configurations can be intensified will be discussed. This includes the intermixing of the four f-states with ligands of the host matrix, excitation to higher d-electronic states. Additional intensification of luminescence by plasmonic interaction with gold, silver and copper nanoparticles will be discussed. A short history of the time development of the research and the names of the scientists who made the major contribution of our understanding of lanthanides spectroscopy are presented.

  20. Medium temperature reaction between lanthanide and actinide carbides and hydrogen

    International Nuclear Information System (INIS)

    Dean, G.; Lorenzelli, R.; Pascard, R.

    1964-01-01

    Hydrogen is fixed reversibly by the lanthanide and actinide mono carbides in the range 25 - 400 C, as for pure corresponding metals. Hydrogen goes into the carbides lattice through carbon vacancies and the total fixed amount is approximately equal to two hydrogen atoms per initial vacancy. Final products c.n thus be considered as carbo-hydrides of general formula M(C 1-x , H 2x ). The primitive CFC, NaCl type, structure remains unchanged but expands strongly in the case of actinide carbides. With lanthanide carbides, hydrogenation induces a phase transformation with reappearance of the metal structure (HCP). Hydrogen decomposition pressures of all the studied carbo-hydrides are greater than those of the corresponding di-hydrides. (authors) [fr

  1. Fluorescence Spectra Studies on the Interaction between Lanthanides and Calmodulin

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The conformation of Calmodulin(CaM) induced by lanthanides has been examined using fluorescence methods.With the addition of lanthanide (Ln3+), the intrinsic fluorescence intensity of CaM without calcium ions (Apo-CaM) first increases and then decreases.Ln3+ causes the decrease of intrinsic fluorescence intensity of calcium saturated CaM (Ca2+4-CaM) only at high concentrations.At low concentrations, Ln3+ results not only in the enhancement of fluorescence intensity of Apo-CaM, but also in a blue shift of the maximum emission wavelengh of dansyl labeled calmodulin(Apo-D-CaM).The molecular mechanism of the interaction between Ln3+ and CaM has been discussed in the light of the fluorescence spectra.

  2. Advancing the scientific basis of trivalent actinide-lanthanide separations

    International Nuclear Information System (INIS)

    Nash, K.L.

    2013-01-01

    For advanced fuel cycles designed to support transmutation of transplutonium actinides, several options have been demonstrated for process-scale aqueous separations for U, Np, Pu management and for partitioning of trivalent actinides and fission product lanthanides away from other fission products. The more difficult mutual separation of Am/Cm from La-Tb remains the subject of considerable fundamental and applied research. The chemical separations literature teaches that the most productive alternatives to pursue are those based on ligand donor atoms less electronegative than O, specifically N- and S-containing complexants and chloride ion (Cl - ). These 'soft-donor' atoms have exhibited usable selectivity in their bonding interactions with trivalent actinides relative to lanthanides. In this report, selected features of soft donor reagent design, characterization and application development will be discussed. The roles of thiocyanate, aminopoly-carboxylic acids and lactate in separation processes are detailed. (authors)

  3. Stability complexes of lanthanide ions with some macrocyclic polyethers

    International Nuclear Information System (INIS)

    Poluehktov, N.S.; Malinka, E.V.; Meshkova, S.B.; Bel'tyukova, S.V.; Danilkovich, M.M.

    1984-01-01

    Stability of lanthanide complexes with macrocyclic polyethers has been studied versus the number of f-electrons, spin- and orbital angular momenta of the Lu 3+ ion ground states. The following compounds were used as macrocyclic complexones: 12-crown-4 (12C4), tert-bulylbenzo-15-crown-5(BB15C5), 18-crown-6 (18C6), ditert-butylbenzo-18-crown-6(DBB18C6), dibenzo-30-crown-10 (DB30C10), cryptand [2, 2, 1] (Cr[2, 2, 1]). It is shoWn that the stability constants of the studied lanthanide complexes can be described rather satisfactorily by an expression suggested earlier that relates their values with the number of 4f-electrons and the S and L quantum numbers of the ground states of the lantharide ions

  4. Quantum chemical prediction of antennae structures in lanthanide complexes

    International Nuclear Information System (INIS)

    Ottonelli, M.; Musso, G.F.; Rizzo, F.; Dellepiane, G.; Porzio, W.; Destri, S.

    2008-01-01

    In this paper the quantum chemical semiempirical procedure recently proposed by us to predict ground- and excited-state geometries of lanthanide complexes, the pseudo coordination centre method (PCC), is preliminarily compared with the semiempirical sparkle model for the calculation of lanthanide complexes (SMLC). Contrary to the SMLC method, where the rare-earth ion is replaced by a reparameterized sparkle atom, in our approach we replace it with a metal ion which is already present in the chosen semiempirical parameterization. This implies that in the optimization of the geometry of the complexes a different weight is implicitly given to the complex region including the rare-earth ion and its neighbour atoms with respect to the region of the ligands aggregate. As a consequence our approach is expected to reproduce better than the SMLC one the geometry of the ligands aggregate embedded in the complex, while the contrary happens for the coordination distances

  5. Synthesis and investigation of uranylphosphates, uranylarsenanes, and uranylvanadates of lanthanides

    International Nuclear Information System (INIS)

    Chernorukov, N.G.; Knyazev, A.V.; Barch, S.V.; Feoktisova, S.V.; Suleymanov, E.V.

    2000-01-01

    Currently compounds A k (B V UO 6 ) k-m (OH) m .nH 2 O (A k - Y, La-Lu, B V -P, As, V) are of interest as the possible mineral-like forms of linkage in an environment of uranium and radioactive isotopes of lanthanides of an artificial origin, as modeling systems for study of similar compounds of six-valence neptunium and plutonium, and as objects, suitable for allocation and division lanthanides and actinides. In order to determine a role of water molecules in the formation of the crystal structure of inorganic hydrates and processes of dehydration uranium minerals with the general formula A k (B V UO 6 ) k-m (OH) m .nH 2 O and their synthetic analogues (A k - one-, two- and three-valent elements, B V -elements of the fifth group of Periodic system) are rather convenient objects. (authors)

  6. Organometallic compounds of the lanthanides, actinides and early transition metals

    Energy Technology Data Exchange (ETDEWEB)

    Cardin, D J [Trinity Coll., Dublin (Ireland); Cotton, S A [Stanground School, Peterborough (UK); Green, M [Bristol Univ. (UK); Labinger, J A [Atlantic Richfield Co., Los Angeles, CA (USA); eds.

    1985-01-01

    This book provides a reference compilation of physical and biographical data on over 1500 of the most important and useful organometallic compounds of the lanthanides, actinides and early transition metals representing 38 different elements. The compounds are listed in molecular formula order in a series of entries in dictionary format. Details of structure, physical and chemical properties, reactions and key references are clearly set out. All the data is fully indexed and a structural index is provided.

  7. Using lanthanide chelates and uranyl compounds for diagnostic by fluoroimmunoassays

    International Nuclear Information System (INIS)

    Santos, Elen G.; Tomiyama, Claudia S.; Kodaira, Claudia A.; Felinto, Maria C.F.C.; Lourenco, Ana V. S.; Brito, Hermi F.

    2009-01-01

    The importance of the luminescence of lanthanide ions and UO 2 2+ is related to its peculiar characteristics, e.g. long lifetime and line-like emission bands in the visible, which make these ions unique among the species that are known to luminescence. Recent developments in the field of supramolecular chemistry have allowed the design of ligands capable of encapsulating lanthanide ions, thus forming kinetically inert complexes. By introduction of chromophoric groups in these ligands, an intense luminescence of the ion can be obtained via the 'antenna effect', defined as a light conversion process involving distinct absorbing (ligand) and emitting (metal ion) components. In such a process, the quantities that contribute to the luminescence intensity are the efficiency of the absorption, the efficiency of the ligand-metal energy transfer, and the efficiency of the metal luminescence. Encapsulation of lanthanide ions with suitable ligands may therefore give rise to 'molecular devices' capable to emit strong, long-lived luminescence. Besides the intrinsic interest in their excited state properties, compounds of lanthanide ions, in particular of the Eu 3+ and Tb 3+ ions, and now UO 2 2+ are important for their potential use as luminescent labels for biological species in fluoroimmunoassays (FIAs). This is most interesting because fluorimetric labeling represents an alternative method to the use of radioactive labels, which has long been the most common way of quantifying immunoreactions. In this article we report information about luminescent materials, which gave a good signal to quantify biological molecules by TR-FIA, DELFIA , DSLFIA, RIA and FRET. (author)

  8. Magnetic dipole moments of odd-odd lanthanides

    International Nuclear Information System (INIS)

    Sharma, S.D.; Gandhi, R.

    1988-01-01

    Magnetic dipole moments of odd-odd lanthanides. Collective model of odd-odd nuclei is applied to predict the magnetic dipole moments, (μ) of odd-odd lanthanides. A simplified version of expression for μ based on diagonalisation of Hamiltonian (subsequent use of eigenvectors to compute μ) is developed for cases of ground state as well as excited states using no configuration mixing and is applied to the cases of odd-odd lanthanides. The formulae applied to the eleven (11) cases of ground states show significant improvement over the results obtained using shell model. Configuration mixing and coriolis coupling is expected to cause further improvement in the results. On comparing the earlier work in this direction the present analysis has clarified that in the expression μ the projection factors have different signs for the case I=Ωp - Ωn and I=Ωn - Ωp, and sign of μ is negative in general in the second case while it is positive in all others of spin projection alignments. Although the general expression holds for excited states as well but in lanthanide region, the experimental reports of magnetic dipole moments of excite states (band heads of higher rational sequences) are not available except in case of five (5) neutron resonance states which cannot be handled on the basis of the present approach with no configuration mixing. Although in the present discussion, the model could not be applied to excited states but the systematics of change in its magnitude with increasing spin at higher rational states is very well understood. The particle part supressed under faster rotation of the nuclear core and thus finally at higher spin I, the value μ is given by μ=g c I (same as in case of even-even nuclei). These systematics are to be verified whenever enough data for higher excited states are available. (author). 11 refs

  9. Lanthanides separation by counter - current electrophoretic using α - hydroxyisobutyric acid

    International Nuclear Information System (INIS)

    Alleluia, I.B.

    1975-01-01

    Studies about counter-current electrophoretic separation of rare earth metal ions using α-hydroxyisobutyric acid as complexing electrolyte are discussed. La, Pr, Nd, Sm and Eu were separated and fractions with purities better than 99,9% were obtained, using neutron activation analysis. A relation between the first stability constant of the α-hydroxyisobutyrate/lanthanide complexes and their migration velocities were observed. (M.J.C.) [pt

  10. Analytical applications of superacid dissolution of actinide and lanthanide substrates

    International Nuclear Information System (INIS)

    Avens, L.R.; Eller, P.G.; Asprey, L.B.; Abney, K.D.; Kinkead, S.A.

    1987-01-01

    The superacid system HF/SbF 5 is extraordinarily effective for total dissolution of actinide and lanthanide ceramic oxides, fluorides, and metals. Optical or gamma spectroscopy can be used directly on the solutions. Evaporation of the HF/SbF 5 solvent under vacuum leaves a residue which is easily dissolved by ordinary mineral acids. The resulting aqueous solutions are readily amenable to conventional analytical methods

  11. Lanthanide and actinide separation studies using liquid chromatography

    International Nuclear Information System (INIS)

    Datta, Arpita; Sivaraman, N.; Srinivasan, T.G.; Vasudeva Rao, P.R.

    2011-01-01

    Gradient elution procedure for isolation of individual lanthanides was studied extensively at our laboratory using monolith support. A large number of gradients were developed by varying the concentrations of CSA, α-HIBA, mobile phase pH and mobile phase flow rate. In a typical gradient run, the concentration of CSA and mobile phase flow rate were kept constant and only α-HIBA concentration was varied. Based on these studies, a binary gradient elution method was developed for the rapid separation of lanthanides, from La to Lu in about 2.8 min, with a mobile phase CSA, α-HIBA and pH being 0.03M, 0.05 to 0.15M and 3.4-3.8 respectively. The direct injection of dissolver solution from FBTR spent fuel into HPLC was investigated and the results are shown. The lanthanides present in dissolver solution were mutually separated as well as resolved from uranium and plutonium under dynamic ion exchange conditions using the monolithic column. The concentration of La, Ce, Pr, Nd and Sm were determined in the dissolver solution using a calibration plot

  12. Lanthanide phosphonates: Synthesis, thermal stability and magnetic characterization

    Energy Technology Data Exchange (ETDEWEB)

    Amghouz, Z., E-mail: amghouz.uo@uniovi.es [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Garcia, J.R.; Garcia-Granda, S. [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Clearfield, A. [Department of Chemistry, Texas A and M University, College Station, TX 77842-3012 (United States); Rodriguez Fernandez, J.; Pedro, I. de [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Blanco, J.A. [Departamento de Fisica, Universidad de Oviedo, 33007 Oviedo (Spain)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Report of the complete series of lanthanide 1,4-phenylbis(phosphonate). Black-Right-Pointing-Pointer Synthesis under conventional hydrothermal synthesis or microwave-assisted hydrothermal synthesis. Black-Right-Pointing-Pointer Cation size is the key factor for the structural and particles size variations. Black-Right-Pointing-Pointer Thermal behaviour is characterized by unusual very high thermal stability. - Abstract: Series of novel organic-inorganic hybrids materials based on trivalent lanthanides (Ln = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) and 1,4-phenylbis(phosphonate) obtained under hydrothermal conditions either by oven heat or microwave irradiation. The anhydrous compounds containing La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Ho, are isostructural. However, the compounds based on Y, Er, Tm, Yb, and Lu are hydrated and their structures have not yet been solved. The series of compounds are characterized by PXRD, TEM, SEM-EDX and thermal analyses (TG-MS and DSC). TEM study show a variable particles size with a minimum mean-particle size of ca. 30 nm. These compounds exhibit unusual very high thermal stability. The size of particles and the thermal stability are depending on lanthanide(III) cation features. All the investigated materials show paramagnetic behaviour. The magnetic susceptibility data follow a Curie-Weiss laws with paramagnetic effective moments in good agreement with those expected for Ln{sup 3+} free ions.

  13. Novel open-framework architectures in lanthanide phosphonates

    Science.gov (United States)

    Groves, John A.; Stephens, Nicholas F.; Wright, Paul A.; Lightfoot, Philip

    2006-03-01

    Two novel three-dimensional lanthanide coordination polymers have been prepared hydrothermally with the phosphonic acid N,N-piperazine bis(methylenephosphonic acid), H 2O 3PCH 2N(C 2H 4) 2NCH 2PO 3H 2 ( LH 4). The structures of Gd 2( LH 2) 3ṡ3H 2O (I) and Nd 2( LH 2) 3ṡ9H 2O (II) have been characterised by single crystal X-ray techniques. One-dimensional 'lanthanide-phosphate' chains are a key feature in both structures, although there are major structural differences between the chains, with (I) displaying octahedral GdO 6 coordination and (II) showing eight-coordinate NdO 8 polyhedra. In each case, three-dimensional connectivity is completed by coordination of the phosphonate group resulting in open framework structures encapsulating loosely bound water molecules. Isostructural Y 3+ and Yb 3+ analogues of (I) have been prepared, suggesting that cation size is a key factor in controlling the differing reaction products. In the case of Y 2( LH 2) 3ṡ5H 2O, isostructural to (I), it is shown that the extra-framework water molecules may be removed reversibly without framework collapse. Structural relationships to other known lanthanide phosphonates are discussed.

  14. Synthesis and characterization of metal soaps of lanthanides (III)

    International Nuclear Information System (INIS)

    Payolla, Filipe Boccato; Ribeiro, Sidney Jose Lima; Massbni, Antonio Carlos

    2015-01-01

    The present study describes synthesis and partial characterization of Eu"3"+, Nd"3"+, Dy"3"+, Tb"3"+ and Yb"3"+ behenate complexes. The compounds were analyzed using IR-Spectroscopy, TG-DTG, DSC, elemental analysis, XRD, luminescence and SEM. The results show the purity of the compounds. The XRD analysis and the SEM images show the high crystallinity of the complexes. TG-DTG and DSC analyses do not show a liquid crystal behavior, as occurs with other lanthanide metallic soaps. The mass loses until 1000° C show that the compounds lose ligand fragments at specific temperatures. XRD of the residues are compatible with the respective lanthanide oxides. The luminescence analysis shows that the Eu"3"+, Nd"3"+ and Tb"3"+ complexes presents appreciable emission. The Judd-Ofelt parameters obtained are compatible with the values found in the literature. It was not possible to obtain the complexes in a glass-form because it is difficult to prevent the crystallization of the complexes even using liquid nitrogen. The XDR data indicate that one of the complexes axis has 52 Å of length, agreeing with a structure containing behenate-lanthanide ion-behenate. The structures of the complexes were not fully elucidated and more analyses are necessary. The complexes presented a molar ratio of 3:1 (L:M) and were formulated as Bh_3Eu, Bh_3Nd, Bh_3Dy, Bh_3Tb e Bh_3Yb (Bh = behenate anion). (author)

  15. Citrate based ''TALSPEAK'' lanthanide-actinide separation process

    International Nuclear Information System (INIS)

    Del Cul, G.D.; Bond, W.D.; Toth, L.M.; Davis, G.D.; Dai, S.; Metcalf, D.H.

    1994-09-01

    The potential hazard posed to future generations by long-lived radionuclides such as the transuranic elements (TRU) is perceived as a major problem associated with the use of nuclear power. TRU wastes have to remain isolated from the environment for ''geological'' periods of time. The costs of building, maintaining, and operating a ''geological TRU repository'' can be very high. Therefore, there are significant economical advantages in segregating the relatively low volume of TRU wastes from other nuclear wastes. The chemical behavior of lanthanides and actinides, 4f and 5f elements respectively, is rather similar. As a consequence, the separation of these two groups is difficult. The ''TALSPEAK'' process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Complexes) is one of the few means available to separate the trivalent actinides from the lanthanides. The method is based on the preferential complexation of the trivalent actinides by an aminopolyacetic acid. Cold experiments showed that by using citric acid the deleterious effects produced by impurities such as zirconium are greatly reduced

  16. Biosorption of lanthanides using three kinds of seaweed biomasses

    International Nuclear Information System (INIS)

    Sakamoto, Nobuo; Wang, Yudan; Gao, Lidi; Kano, Naoki; Imaizumi, Hiroshi

    2010-01-01

    In order to evaluate the efficiency of seaweed biomass as sorbent for rare earth elements (REEs), sorption experiment from aqueous solutions containing known amount of lanthanide (La, Eu or Yb) using three kinds of Ca-loaded dried seaweeds (brown algae: Sargassum hemiphyllum, green algae: Ulva pertusa and red algae: Schizymenia dubyi) in single component system was explored. Furthermore, the sorption mechanism of these elements was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, to confirm the characteristics of the seaweed biomasses, the surface morphology of the biomass before and after metal adsorption was determined by Scanning Electron Microscope (SEM). Consequently, the following matters have been mainly clarified. (1) The morphology of Sargassum hemiphyllum and Ulva pertusa surface has hardly changed even after exposing to metals. On the other hand, the change of the surface condition on Schizymenia dubyi after adsorption was observed. (2) Adsorption isotherms using the seaweed biomass can be described by Langmuir and Freundlich isotherms satisfactorily for lanthanide. These adsorption may have occurred mainly by monolayer reaction because of better-fitting for Langmuir model. (3) The seaweed biomasses could be an efficient sorbent for REEs. Particularly, Ulva pertusa is found to be a promising biosorbent for removing La. (4) Ion-exchange process is considered to be the main mechanism responsible for the sorption of lanthanide ion onto the seaweed biomass. (author)

  17. The reactive element effect of yttrium and yttrium silicon on high temperature oxidation of NiCrAl coating

    Science.gov (United States)

    Ramandhany, S.; Sugiarti, E.; Desiati, R. D.; Martides, E.; Junianto, E.; Prawara, B.; Sukarto, A.; Tjahjono, A.

    2018-03-01

    The microstructure formed on the bond coat affects the oxidation resistance, particularly the formation of a protective oxide layer. The adhesion of bond coat and TGO increased significantly by addition of reactive element. In the present work, the effect of yttrium and yttrium silicon as reactive element (RE) on NiCrAl coating was investigated. The NiCrAl (without RE) and NiCrAlX (X:Y or YSi) bond coating were deposited on Hastelloy C-276 substrate by High Velocity Oxygen Fuel (HVOF) method. Isothermal oxidation was carried out at 1000 °C for 100 hours. The results showed that the addition of RE could prevent the breakaway oxidation. Therefore, the coating with reactive element were more protective against high temperature oxidation. Furthermore, the oxidation rate of NiCrAlY coating was lower than NiCrAlYSi coating with the total mass change was ±2.394 mg/cm2 after 100 hours of oxidation. The thickness of oxide scale was approximately 1.18 μm consisting of duplex oxide scale of spinel NiCr2O4 in outer scale and protective α-Al2O3 in inner scale.

  18. Recovery of yttrium from cathode ray tubes and lamps’ fluorescent powders: experimental results and economic simulation

    International Nuclear Information System (INIS)

    Innocenzi, V.; De Michelis, I.; Ferella, F.; Vegliò, F.

    2013-01-01

    Highlights: • Fluorescent powder of lamps. • Fluorescent powder of cathode ray rubes. • Recovery of yttrium from fluorescent powders. • Economic simulation for the processes to recover yttrium from WEEE. - Abstract: In this paper, yttrium recovery from fluorescent powder of lamps and cathode ray tubes (CRTs) is described. The process for treating these materials includes the following: (a) acid leaching, (b) purification of the leach liquors using sodium hydroxide and sodium sulfide, (c) precipitation of yttrium using oxalic acid, and (d) calcinations of oxalates for production of yttrium oxides. Experimental results have shown that process conditions necessary to purify the solutions and recover yttrium strongly depend on composition of the leach liquor, in other words, whether the powder comes from treatment of CRTs or lamp. In the optimal experimental conditions, the recoveries of yttrium oxide are about 95%, 55%, and 65% for CRT, lamps, and CRT/lamp mixture (called MIX) powders, respectively. The lower yields obtained during treatments of MIX and lamp powders are probably due to the co-precipitation of yttrium together with other metals contained in the lamps powder only. Yttrium loss can be reduced to minimum changing the experimental conditions with respect to the case of the CRT process. In any case, the purity of final products from CRT, lamps, and MIX is greater than 95%. Moreover, the possibility to treat simultaneously both CRT and lamp powders is very important and interesting from an industrial point of view since it could be possible to run a single plant treating fluorescent powder coming from two different electronic wastes

  19. Selective removal of lanthanides from natural waters, acidic streams and dialysate

    Energy Technology Data Exchange (ETDEWEB)

    Yantasee, Wassana, E-mail: wassana.yantasee@pnl.gov [Pacific Northwest National Laboratory (PNNL), P.O. Box 999, Richland, WA 99352 (United States); Fryxell, Glen E.; Addleman, R. Shane; Wiacek, Robert J.; Koonsiripaiboon, View; Pattamakomsan, Kanda; Sukwarotwat, Vichaya [Pacific Northwest National Laboratory (PNNL), P.O. Box 999, Richland, WA 99352 (United States); Xu Jide; Raymond, Kenneth N. [Chemistry Department, University of California, Berkeley, CA 94720 (United States); LBNL, Berkeley, CA 94720 (United States)

    2009-09-15

    The increased demand for the lanthanides in commercial products result in increased production of lanthanide containing ores, which increases public exposure to the lanthanides, both from various commercial products and from production wastes/effluents. This work investigates lanthanide (La, Ce, Pr, Nd, Eu, Gd and Lu) binding properties of self-assembled monolayers on mesoporous silica supports (SAMMS{sup TM}), that were functionalized with diphosphonic acid (DiPhos), acetamide phosphonic acid (AcPhos), propionamide phosphonic acid (Prop-Phos), and 1-hydroxy-2-pyridinone (1,2-HOPO), from natural waters (river, ground and sea waters), acid solutions (to mimic certain industrial process streams), and dialysate. The affinity, capacity, and kinetics of the lanthanide sorption, as well as regenerability of SAMMS materials were investigated. Going from the acid side over to the alkaline side, the AcPhos- and DiPhos-SAMMS maintain their outstanding affinity for lanthanides, which enable the use of the materials in the systems where the pH may fluctuate. In acid solutions, Prop-Phos- and 1,2-HOPO-SAMMS have differing affinity along the lanthanide series, suggesting their use in chromatographic lanthanide separation. Over 95% of 100 {mu}g/L of Gd in dialysate was removed by the Prop-Phos-SAMMS after 1 min and 99% over 10 min. SAMMS can be regenerated with an acid wash (0.5 M HCl) without losing the binding properties. Thus, they have a great potential to be used as in large-scale treatment of lanthanides, lanthanide separation prior to analytical instruments, and in sorbent dialyzers for treatment of acute lanthanide poisoning.

  20. Selective removal of lanthanides from natural waters, acidic streams and dialysate

    International Nuclear Information System (INIS)

    Yantasee, Wassana; Fryxell, Glen E.; Addleman, R. Shane; Wiacek, Robert J.; Koonsiripaiboon, View; Pattamakomsan, Kanda; Sukwarotwat, Vichaya; Xu Jide; Raymond, Kenneth N.

    2009-01-01

    The increased demand for the lanthanides in commercial products result in increased production of lanthanide containing ores, which increases public exposure to the lanthanides, both from various commercial products and from production wastes/effluents. This work investigates lanthanide (La, Ce, Pr, Nd, Eu, Gd and Lu) binding properties of self-assembled monolayers on mesoporous silica supports (SAMMS TM ), that were functionalized with diphosphonic acid (DiPhos), acetamide phosphonic acid (AcPhos), propionamide phosphonic acid (Prop-Phos), and 1-hydroxy-2-pyridinone (1,2-HOPO), from natural waters (river, ground and sea waters), acid solutions (to mimic certain industrial process streams), and dialysate. The affinity, capacity, and kinetics of the lanthanide sorption, as well as regenerability of SAMMS materials were investigated. Going from the acid side over to the alkaline side, the AcPhos- and DiPhos-SAMMS maintain their outstanding affinity for lanthanides, which enable the use of the materials in the systems where the pH may fluctuate. In acid solutions, Prop-Phos- and 1,2-HOPO-SAMMS have differing affinity along the lanthanide series, suggesting their use in chromatographic lanthanide separation. Over 95% of 100 μg/L of Gd in dialysate was removed by the Prop-Phos-SAMMS after 1 min and 99% over 10 min. SAMMS can be regenerated with an acid wash (0.5 M HCl) without losing the binding properties. Thus, they have a great potential to be used as in large-scale treatment of lanthanides, lanthanide separation prior to analytical instruments, and in sorbent dialyzers for treatment of acute lanthanide poisoning.

  1. Lanthanide tris(β-diketonates) as useful probes for chirality determination of biological amino alcohols in vibrational circular dichroism: ligand to ligand chirality transfer in lanthanide coordination sphere.

    Science.gov (United States)

    Miyake, Hiroyuki; Terada, Keiko; Tsukube, Hiroshi

    2014-06-01

    A series of lanthanide tris(β-diketonates) functioned as useful chirality probes in the vibrational circular dichroism (VCD) characterization of biological amino alcohols. Various chiral amino alcohols induced intense VCD signals upon ternary complexation with racemic lanthanide tris(β-diketonates). The VCD signals observed around 1500 cm(-1) (β-diketonate IR absorption region) correlated well with the stereochemistry and enantiomeric purity of the targeted amino alcohol, while the corresponding monoalcohol, monoamine, and diol substrates induced very weak VCD signals. The high-coordination number and dynamic property of the lanthanide complex offer an effective chirality VCD probing of biological substrates. © 2014 Wiley Periodicals, Inc.

  2. Neutron activation determination of oxygen in ceramic materials on the basis of yttrium, barium and copper

    International Nuclear Information System (INIS)

    Goldshtein, M.M.; Yudelevich, I.G.

    1991-01-01

    A procedure of determining oxygen in superconducting materials on the basis of yttrium, barium and copper oxides with the application of 14 MeV-neutron activation was developed. The method is based on determining the relation between oxygen and yttrium in the compounds investigated. In order to minimize systematic errors, expressions accounting for spectrometer dead time under conditions of varying component activity are proposed. The procedure ensures determination of the relation between oxygen and yttrium with a relative error of 0.4% with NAA using a neutron generator. (author) 4 refs.; 1 fig

  3. Study of behaviour of lanthanum- and yttrium electrodes in chloride melts

    International Nuclear Information System (INIS)

    Shkol'nikov, S.I.; Tolypin, E.S.; Yur'ev, B.P.

    1984-01-01

    A study was made on the lanthanum- and yttrium behaviour in a mixture of molten potassium- and sodium chlorides at various temperatures. It is shown that the lanthanum- and yttrium behaviour in KCl-NaCl melt is similar to the behaviour of other metals. Their corrosion rate is much higher as compared to other metals and it grows rapidly with increasing melt temperature. The temperature growth by 200 deg C results in an increase in the corrosion rate almost by an order. The potentials of lanthanum- and yttrium electrodes at the instant they are immersed in the melt have more negative values than the potentials of alkali metals under similar conditions

  4. Effect of yttrium chromite doping on its resistance to high-temperature salt and gas corrosions

    International Nuclear Information System (INIS)

    Oryshich, I.V.; Poryadchenko, N.E.; Rakitskij, A.N.; Bega, N.D.

    1996-01-01

    Effect of yttrium chromite doping with 2-4 group metal oxides on the corrosion resistance in the air at 1300 C during 5 hours and in sodium chloride and sulfate melts at 900 C during 20 hours is investigated. A notable increase of corrosion resistance is achieved under complex doping with zirconium and magnesium oxides in a quantity, close to solubility in yttrium oxide and solubility by aluminium oxide. Doping with calcium and strontium oxides in the quantities, dose to solubility in yttrium oxide does not produce any notable effect, and at higher concentrations it reduces the corrosion resistance in media indicated. Refs. 8, refs. 2, tabs. 1

  5. Self-Assembled Nanocomposite Organic Polymers with Aluminum and Scandium as Heterogeneous Water-Compatible Lewis Acid Catalysts.

    Science.gov (United States)

    Miyamura, Hiroyuki; Sonoyama, Arisa; Hayrapetyan, Davit; Kobayashi, Shū

    2015-09-01

    While water-compatible Lewis acids have great potential as accessible and environmentally benign catalysts for various organic transformations, efficient immobilization of such Lewis acids while keeping high activity and without leaching of metals even under aqueous conditions is a challenging task. Self-assembled nanocomposite catalysts of organic polymers, carbon black, aluminum reductants, and scandium salts as heterogeneous water-compatible Lewis acid catalysts are described. These catalysts could be successfully applied to various C-C bond-forming reactions without leaching of metals. Scanning transmission electron microscopy analyses revealed that the nanocomposite structure of Al and Sc was fabricated in these heterogeneous catalysts. It is noted that Al species, which are usually decomposed rapidly in the presence of water, are stabilized under aqueous conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Scandium doping brings speed improvement in Sb2Te alloy for phase change random access memory application.

    Science.gov (United States)

    Chen, Xin; Zheng, Yonghui; Zhu, Min; Ren, Kun; Wang, Yong; Li, Tao; Liu, Guangyu; Guo, Tianqi; Wu, Lei; Liu, Xianqiang; Cheng, Yan; Song, Zhitang

    2018-05-01

    Phase change random access memory (PCRAM) has gained much attention as a candidate for nonvolatile memory application. To develop PCRAM materials with better properties, especially to draw closer to dynamic random access memory (DRAM), the key challenge is to research new high-speed phase change materials. Here, Scandium (Sc) has been found it is helpful to get high-speed and good stability after doping in Sb 2 Te alloy. Sc 0.1 Sb 2 Te based PCRAM cell can achieve reversible switching by applying even 6 ns voltage pulse experimentally. And, Sc doping not only promotes amorphous stability but also improves the endurance ability comparing with pure Sb 2 Te alloy. Moreover, according to DFT calculations, strong Sc-Te bonds lead to the rigidity of Sc centered octahedrons, which may act as crystallization precursors in recrystallization process to boost the set speed.

  7. Random-field Potts model for the polar domains of lead magnesium niobate and lead scandium tantalate

    Energy Technology Data Exchange (ETDEWEB)

    Qian, H.; Bursill, L.A

    1997-06-01

    A random filed Potts model is used to establish the spatial relationship between the nanoscale distribution of charges chemical defects and nanoscale polar domains for the perovskite-based relaxor materials lead magnesium niobate (PMN) and lead scandium tantalate (PST). The random fields are not set stochastically but are determined initially by the distribution of B-site cations (Mg, Nb) or (Sc, Ta) generated by Monte Carlo NNNI-model simulations for the chemical defects. An appropriate random field Potts model is derived and algorithms developed for a 2D lattice. It is shown that the local fields are strongly correlated with the chemical domain walls and that polar domains as a function of decreasing temperature is simulated for the two cases of PMN and PST. The dynamics of the polar clusters is also discussed. 33 refs., 9 figs.

  8. Modification of radiation sensitivity by salts of the metals beryllium and indium and the rare earths cerium, lanthanum and scandium

    International Nuclear Information System (INIS)

    Floersheim, G.L.

    1995-01-01

    The LD 50 of 46 salts of metals and rare earths (lanthanoids) was determined in mice. Half the LD 50 of the compounds was then combined with lethal radiation (10.5 Gy) and the modification of survival time was scored. Only the metals beryllium and indium and the rare earths cerium, lanthanum and scandium displayed activity in our assay. There were then tested at a wider range of lower doses and reduced survival time in a dose-dependent fashion. This appears to be compatible with enhancement of radiation sensitivity. The interaction of these metals and rare earths with radiation adds a new facet to their toxicological spectrum and, by enhancing radiation effects, may influence estimates of risk. On the other hand, radiosensitizing properties of the metals may be useful for further development of compounds to be used as adjuncts in specific situations of cancer radiotherapy. 31 refs., 1 fig., 1 tab

  9. Energy transfer and quenching processes of excited uranyl ion and lanthanide ions in solutions

    International Nuclear Information System (INIS)

    Yamamura, Tomoo; Tomiyasu, Hiroshi

    1995-01-01

    Deactivation processes of photoexcited uranyl ion by various lanthanide ions in aqueous solution were studied. Each lanthanide ions show different interaction with excited uranyl ion depending on its lowest excited energy level, the number of 4f electrons and the acid concentration of the solution. (author)

  10. Spectrally resolved confocal microscopy using lanthanide centred near-IR emission

    DEFF Research Database (Denmark)

    Liao, Zhiyu; Tropiano, Manuel; Mantulnikovs, Konstantins

    2015-01-01

    The narrow, near infrared (NIR) emission from lanthanide ions has attracted great interest, particularly with regard to developing tools for bioimaging, where the long lifetimes of lanthanide excited states can be exploited to address problems arising from autofluorescence and sample transparency...

  11. Coordination symmetry determination of some lanthanide complexes by x-ray diffraction

    International Nuclear Information System (INIS)

    Oliveira Paiva Santos, C. de.

    1983-01-01

    The x-ray determination of the crystal and molecular structures of three lanthanide complexes is described. The work is a contribution to the study of the coordination chemistry of lanthanide ions with organic ligands and in particular, it aims to compare the observed point symmetry of the ion environment with spectroscopic predictions. (author)

  12. Tuning the sensitivity of lanthanide-activated NIR nanothermometers in the biological windows

    NARCIS (Netherlands)

    Cortelletti, P.; Skripka, A.; Facciotti, C.; Pedroni, M.; Caputo, G.; Pinna, N.; Quintanilla, M.; Benayas, A.; Vetrone, F.; Speghini, A.

    2018-01-01

    Lanthanide-activated SrF2 nanoparticles with a multishell architecture were investigated as optical thermometers in the biological windows. A ratiometric approach based on the relative changes in the intensities of different lanthanide (Nd3+ and Yb3+) NIR emissions was applied to investigate the

  13. Recovery of uranium and lanthanides during the production of nitrophosphate fertilizers using tertiary amyl alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Habashi, F; Awadalla, F T

    1986-01-01

    When phosphate rock is dissolved in nitric acid, phosphoric acid and uranium can be selectively extracted by tertiary amyl alcohol; other impurities including the lanthanides remain in the aqueous phase. Uranium can be recovered from the alcohol phase by selective stripping and the lanthanides from the raffinate by extraction with tributyl phosphate.

  14. The spectrum of singly ionized yttrium, Y II

    International Nuclear Information System (INIS)

    Nilsson, A.E.; Johansson, S.; Kurucz, R.L.

    1991-01-01

    Hollow-cathode spectra of yttrium have been registered in the wavelength region 1000-48800 A. Resonant charge transfer reactions in the light source favour the excitation of Y II, where 174 new levels have been established by means of 1284 newly classified lines. Altogether we report 1521 lines between 235 levels in Y II. The ground complex (4d+5s) 2 is now completely known and a number of Rydberg series have been extended. The new levels belong to the 4dnl (nl=7s, 8s, 9s, 6p, 7p, 4d, 5d, 6d, 7d, 8d, 4f, 5f, 6f, 7f, 5g) and 5snl (nl=7s, 8s, 6p, 6d, 4f, 5f) configurations. Eigenvector compositions, based on paramagnetic calculations including configuration interaction, are given for all levels. The ionization limit has been determined to 98590 ± 5 cm -1 . (orig.)

  15. Calorimetric investigation of an yttrium-dysprosium spin glass

    International Nuclear Information System (INIS)

    Wenger, L.E.

    1978-01-01

    In an effort to compare the spin glass characteristics of yttrium--rare earth alloys with those of the noble-metal spin glasses, the susceptibility and heat capacity of Y/sub 0.98/Dy/sub 0.02/ have been measured in the temperature range 2.5--40 K. The low-field ac susceptibility measurement shows the characteristic cusp-like peak at 7.64 K. The magnetic specific heat of the same sample shows a peak at 7.0 K and may be qualitatively described as a semi-cusp. The magnetic entropy change from absolute zero to 7 K is approximately 0.52 of cR ln(2J+1). These results are qualitatively different than previous calorimetric results on the archetypal spin glasses, AuFe and CuMn, where rounded maxima are observed at temperatures above the spin glass transition temperatures

  16. RBS Characterization of Yttrium Iron Garnet Thin Films

    International Nuclear Information System (INIS)

    Roumie, M; Abdel samad, B.

    2008-01-01

    Magnetic materials such as yttrium iron garnet (YIG) are of great importance for its magneto-optic properties and for their potential applications in the domain of optical telecommunications. The deposition of thin films of YIG, on quartz or GGG (gadolinium gallium garnet) substrate, was performed using radio frequency non reactive magnetron sputtering, followed by high temperature annealing which is needed to enhance the crystallinity of the layers. Rutherford backscattering spectrometry RBS was used to determine the thickness and stoichiometry of the performed layers in order to investigate correlations between growth conditions and the quality of the final material. RBS measurements showed the influence of the deposition time and the temperature substrate on the film growth and its stoichiometry. (author)

  17. A divalent rare earth oxide semiconductor: Yttrium monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Kaminaga, Kenichi; Sei, Ryosuke [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); Department of Chemistry, Tohoku University, Sendai 980-8578 (Japan); Hayashi, Kouichi [Department of Environmental and Materials Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Happo, Naohisa [School of Information Sciences, Hiroshima City University, Hiroshima 731-3194 (Japan); Tajiri, Hiroo [Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8, Sayo 679-5198 (Japan); Oka, Daichi; Fukumura, Tomoteru, E-mail: tomoteru.fukumura.e4@tohoku.ac.jp [Department of Chemistry, Tohoku University, Sendai 980-8578 (Japan); Hasegawa, Tetsuya [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan)

    2016-03-21

    Rare earth oxides are usually widegap insulators like Y{sub 2}O{sub 3} with closed shell trivalent rare earth ions. In this study, solid phase rock salt structure yttrium monoxide, YO, with unusual valence of Y{sup 2+} (4d{sup 1}) was synthesized in a form of epitaxial thin film by pulsed laser deposition method. YO has been recognized as gaseous phase in previous studies. In contrast with Y{sub 2}O{sub 3}, YO was dark-brown colored and narrow gap semiconductor. The tunable electrical conductivity ranging from 10{sup −1} to 10{sup 3} Ω{sup −1 }cm{sup −1} was attributed to the presence of oxygen vacancies serving as electron donor. Weak antilocalization behavior observed in magnetoresistance indicated significant role of spin-orbit coupling as a manifestation of 4d electron carrier.

  18. Tunable negative index metamaterial using yttrium iron garnet

    International Nuclear Information System (INIS)

    He, Yongxue; He, Peng; Dae Yoon, Soack; Parimi, P.V.; Rachford, F.J.; Harris, V.G.; Vittoria, C.

    2007-01-01

    A magnetic field tunable, broadband, low-loss, negative refractive index metamaterial is fabricated using yttrium iron garnet (YIG) and a periodic array of copper wires. The tunability is demonstrated from 18 to 23 GHz under an applied magnetic field with a figure of merit of 4.2 GHz/kOe. The tuning bandwidth is measured to be 5 GHz compared to 0.9 GHz for fixed field. We measure a minimum insertion loss of 4 dB (or 5.7 dB/cm) at 22.3 GHz. The measured negative refractive index bandwidth is 0.9 GHz compared to 0.5 GHz calculated by the transfer function matrix theory and 1 GHz calculated by finite element simulation

  19. {alpha}-particle induced reactions on yttrium and terbium

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S.; Kumar, B.B. [School of Studies in Physics, Vikram University, Ujjain-456010 (India); Rashid, M.H. [Variable Energy Cyclotron Center, 1/AF, Bidhan Nagar, Calcutta (India); Chintalapudi, S.N. [Inter-University Consortium for DAE Facilities, 3/LB, Bidhan Nagar, Calcutta (India)

    1997-05-01

    The stacked foil activation technique has been employed for the investigation of {alpha}-particle induced reactions on the target elements yttrium and terbium up to 50 MeV. Six excitation functions for the ({alpha},xn) type of reactions were studied using high-resolution HPGe {gamma}-ray spectroscopy. A comparison with Blann{close_quote}s geometric dependent hybrid model has been made using the initial exciton number n{sub 0}=4(4p0h) and n{sub 0}=5(5p0h). A broad general agreement is observed between the experimental results and theoretical predictions with an initial exciton number n{sub 0}=4(4p0h). {copyright} {ital 1997} {ital The American Physical Society}

  20. α-particle induced reactions on yttrium and terbium

    International Nuclear Information System (INIS)

    Mukherjee, S.; Kumar, B.B.; Rashid, M.H.; Chintalapudi, S.N.

    1997-01-01

    The stacked foil activation technique has been employed for the investigation of α-particle induced reactions on the target elements yttrium and terbium up to 50 MeV. Six excitation functions for the (α,xn) type of reactions were studied using high-resolution HPGe γ-ray spectroscopy. A comparison with Blann close-quote s geometric dependent hybrid model has been made using the initial exciton number n 0 =4(4p0h) and n 0 =5(5p0h). A broad general agreement is observed between the experimental results and theoretical predictions with an initial exciton number n 0 =4(4p0h). copyright 1997 The American Physical Society

  1. Thermal conductivity of yttrium iron garnet at low temperatures

    International Nuclear Information System (INIS)

    Joshi, Y.P.; Sing, D.P.

    1979-01-01

    An analysis of the low-temperature thermal conductivity of yttrium iron garnet is presented giving consideration to the fact that in a conventional conductivity experiment the magnon temperature gradient inside a magnetic insulator need not be necessarily equal to the phonon temperature gradient. Consequently the effective conductivity can be less than the algebraic sum of the phonon and magnon intrinsic conductivities, depending on the magnon-phonon thermal relaxation rate. This relaxation rate has been distinguished from the individual phonon and magnon relaxation rates and an expression is derived for it. Theoretical calculations of the effective conductivity are found to be in good agreement with experimental results. The contribution of magnons to the effective conductivity is observed to be small at all temperatures below the conductivity maximum. (author)

  2. Yttrium orthoferrite powder obtained by the mechanochemical synthesis

    Directory of Open Access Journals (Sweden)

    Lazarević Zorica Ž.

    2017-01-01

    Full Text Available Yttrium orthoferrite (YFeO3 powder was prepared by a mechanochemical synthesis from a mixture of Y2O3 and α-Fe2O3 powders in a planetary ball mill for 2.5 h. The obtained YFeO3 powder sample was characterized by X-ray diffraction (XRD, Raman and infrared spectroscopy. The average crystallite size calculated by the Scherrer equation was 12 nm. The Mössbauer spectroscopy at room temperature confirms the superparamagnetic character of YFeO3 orthoferrite sample. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 45003, Grant no. III 45015, Grant no. III 45018

  3. Nanoscale nonlinear effects in Erbium-implanted Yttrium Orthosilicate

    Energy Technology Data Exchange (ETDEWEB)

    Kukharchyk, Nadezhda, E-mail: nadezhda.kukharchyk@physik.uni-saarland.de [Experimentalphysik, Universität des Saarlandes, D-66123 Saarbrücken (Germany); Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Shvarkov, Stepan [Optoelektronische Materialien und Bauelemente, Universität Paderborn, D-33098 Padeborn (Germany); Probst, Sebastian [Quantronics group, Service de Physique de l' Etat Condense, DSM/IRAMIS/SPEC, CNRS UMR 3680, CEA-Saclay, 91191 Gif-sur-Yvette cedex (France); Xia, Kangwei [3. Physikalisches Institut, Universität Stuttgart, D-70569 Stuttgart (Germany); Becker, Hans-Werner [RUBION, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Pal, Shovon [Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); AG THz Spectroscopie und Technologie, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Markmann, Sergej [AG THz Spectroscopie und Technologie, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Kolesov, Roman; Siyushev, Petr; Wrachtrup, Jörg [3. Physikalisches Institut, Universität Stuttgart, D-70569 Stuttgart (Germany); Ludwig, Arne [Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Ustinov, Alexey V. [Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe (Germany); Wieck, Andreas D. [Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); and others

    2016-09-15

    Doping of substrates at desired locations is a key technology for spin-based quantum memory devices. Focused ion beam implantation is well-suited for this task due to its high spacial resolution. In this work, we investigate ion-beam implanted Erbium ensembles in Yttrium Orthosilicate crystals by means of confocal photoluminescence spectroscopy. The sample temperature and the post-implantation annealing step strongly reverberate in the properties of the implanted ions. We find that hot implantation leads to a higher activation rate of the ions. At high enough fluences, the relation between the fluence and final concentration of ions becomes non-linear. Two models are developed explaining the observed behavior.

  4. Successful treatment of Cushing's disease using yttrium-90 rods

    International Nuclear Information System (INIS)

    White, M.C.; Doyle, F.H.; Mashiter, K.; Joplin, G.F.

    1982-01-01

    Interstitial irradiation using yttrium-90 ( 90 Y) rods implanted by needle into the pituitary gland was used as primary treatment in 16 patients with pituitary dependent Cushing's disease. Clinical and biochemical remission was observed within three to six months in 13 and in the remaining three after a supplementary implant. There was no perioperative morbidity. Follow-up from the time of definitive operation ranged from six to 123 months (mean 39). No recurrence has been observed. The return of a normal diurnal cortisol rhythm has been observed in 10/12 patients studied after remission. Some form of long-term pituitary hormone replacement therapy was required in only the six patients who had received the largest irradiation dose. Implantation of 90 Y is safe and effective treatment for patients with Cushing's disease, comparing favourably with selective trans-sphenoidal pituitary surgery. (author)

  5. Estimation of formation heat of rare earth and actinide alloys

    International Nuclear Information System (INIS)

    Shubin, A.B.; Yamshchikov, L.F.; Raspopin, S.P.

    1986-01-01

    A method for forecasting the enthalpy of formation of scandium, yttrium, lanthanum and lanthanides, thorium, uranium and plutonium alloys with a series of fusible metals (Al, Ga, In, Tl, Sn, Pb, Sb, Bi) is proposed. The obtained confidence internal value for the calculated Δ f H 0 values exceeds sufficiently the random error of the experimental determination of the rare metal alloy formation enthalpies. However, taking into account considerable divergences in results of Δ f H 0 determinations performed by different science groups, one may conclude, that such forecasting accuracy may be useful in the course of estimation calculations, especially, for actinide element alloys

  6. Effect of indium addition in U-Zr metallic fuel on lanthanide migration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 S. Cass Ave, Argonne, IL 60439 (United States); Wiencek, T.; O' Hare, E.; Fortner, J.; Wright, A. [Argonne National Laboratory, 9700 S. Cass Ave, Argonne, IL 60439 (United States); Cheon, J.S.; Lee, B.O. [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2017-02-15

    Advanced fast reactor concepts to achieve ultra-high burnup (∼50%) require prevention of fuel-cladding chemical interaction (FCCI). Fission product lanthanide accumulation at high burnup is substantial and significantly contributes to FCCI upon migration to the cladding interface. Diffusion barriers are typically used to prevent interaction of the lanthanides with the cladding. A more active method has been proposed which immobilizes the lanthanides through formation of stable compounds with an additive. Theoretical analysis showed that indium, thallium, and antimony are good candidates. Indium was the strongest candidate because of its low reactivity with iron-based cladding alloys. Characterization of the as-fabricated alloys was performed to determine the effectiveness of the indium addition in forming compounds with lanthanides, represented by cerium. Tests to examine how effectively the dopant prevents lanthanide migration under a thermal gradient were also performed. The results showed that indium effectively prevented cerium migration.

  7. Effect of indium addition in U-Zr metallic fuel on lanthanide migration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo; Wiencek, T.; O' Hare, E.; Fortner, J.; Wright, A.; Cheon, J. S.; Lee, B. O.

    2017-02-01

    Advanced fast reactor concepts to achieve ultra-high burnup (~50%) require prevention of fuel-cladding chemical interaction (FCCI). Fission product lanthanide accumulation at high burnup is substantial and significantly contributes to FCCI upon migration to the cladding interface. Diffusion barriers are typically used to prevent interaction of the lanthanides with the cladding. A more active method has been proposed which immobilizes the lanthanides through formation of stable compounds with an additive. Theoretical analysis showed that indium, thallium, and antimony are good candidates. Indium was the strongest candidate because of its low reactivity with iron-based cladding alloys. Characterization of the as-fabricated alloys was performed to determine the effectiveness of the indium addition in forming compounds with lanthanides, represented by cerium. Tests to examine how effectively the dopant prevents lanthanide migration under a thermal gradient were also performed. The results showed that indium effectively prevented cerium migration.

  8. Separation of Am from lanthanides by a synergistic mixture of purified Cyanex 301 and TBP

    International Nuclear Information System (INIS)

    Xinghai Wang; Yongjun Zhu; Rongzhou Jiao

    2002-01-01

    The dependence of the distribution ratios of 241 Am and lanthanides between purified Cyanex 301 (HBTMPDTP)-TBP-kerosene/nitrate solution on pH, lanthanide concentration in aqueous phase and degree of saponification of HBTMPDTP was investigated. The distribution ratios of 241 Am and lanthanides increase with pH and degree of saponification of HBTMPDTP and decrease with lanthanides concentration. Countercurrent multistage extraction consisting of 7 extraction, 3 washing and 2 stripping stages showed that more than 99,99% of 241 Am and less than 0.04% of lanthanides were extracted. The pH 1/2 value of Am was 2.45 compared to 3.16 in case of HBTMPDTP-kerosene extraction. (author)

  9. Photocatalysis of Yttrium Doped BaTiO3 Nanofibres Synthesized by Electrospinning

    Directory of Open Access Journals (Sweden)

    Zhenjiang Shen

    2015-01-01

    Full Text Available Yttrium doped barium titanate (BT nanofibres (NFs with significant photocatalytic effect were successfully synthesized by electrospinning. Considering the necessary factors for semiconductor photocatalysts, a well-designed procedure was carried out to produce yttrium doped BT (BYT NFs. In contrast to BYT ceramics powders and BT NFs, BYT NFs with pure perovskite phase showed much enhanced performance of photocatalysis. The surface modification in electrospinning and subsequent annealing, the surface spreading of transition metal yttrium, and the narrowed band gap energy in yttrium doping were all contributed to the final novel photocatalytic effect. This work provides a direct and efficient route to obtain doped NFs, which has a wide range of potential applications in areas based on complex compounds with specific surface and special doping effect.

  10. Polymer Derived Yttrium Silicate Ablative TPS Materials for Next-Generation Exploration Missions, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Through the proposed NASA SBIR program, NanoSonic will optimize its HybridSil® derived yttrium silicates to serve as next-generation reinforcement for carbon and...

  11. Synthesis of yttrium oxide nanoparticles via a facile microplasma-assisted process

    NARCIS (Netherlands)

    Lin, Liangliang; Starostin, Sergey A.; Li, Sirui; Khan, Saif A.; Hessel, Volker

    2018-01-01

    Plasma electrochemistry is an emerging technique for nanomaterial synthesis. The present study reports the preparation of yttrium oxide nanoparticles via a simple, environmentally benign, microplasma-assisted process operated in pin-to-liquid configuration under ambient atmospheric conditions using

  12. Cathodoluminescence properties of yttrium aluminum garnet doped with Eu2+ and Eu3+ ions

    International Nuclear Information System (INIS)

    Trofimov, A. N.; Petrova, M. A.; Zamoryanskaya, M. V.

    2007-01-01

    Yttrium aluminium garnet (YAG) doped with Eu 2+ and Eu 3+ ions is very interesting as a phosphor for conversion of light-emitting diode light for white light sources. The europium ion occupies the structural position of yttrium in yttrium aluminium garnet and has valence state Eu 3+ . Our sample was doped with Zr 4+ , which is why some of the europium ions had valence state Eu 2+ . As a rule, luminescence of Eu 3+ ions is observed in the orange and red range of spectrum. The luminescence of Eu 2+ in yttrium aluminum garnet is characterized by an intensive broad band with maximum of intensity at about 560 nm (green color). In this work, we studied the intensity and decay time dependences on europium concentration, and the influence of excitation power density on the cathodoluminescence of the sample. The most interesting result is the change of visible cathodoluminescence color in dependence on the density of the exciting power

  13. The effect of core and lanthanide ion dopants in sodium fluoride-based nanocrystals on phagocytic activity of human blood leukocytes

    International Nuclear Information System (INIS)

    Sojka, Bartlomiej; Liskova, Aurelia; Kuricova, Miroslava; Banski, Mateusz; Misiewicz, Jan; Dusinska, Maria; Horvathova, Mira; Ilavska, Silvia; Szabova, Michaela; Rollerova, Eva; Podhorodecki, Artur; Tulinska, Jana

    2017-01-01

    Sodium fluoride-based β-NaLnF4 nanoparticles (NPs) doped with lanthanide ions are promising materials for application as luminescent markers in bio-imaging. In this work, the effect of NPs doped with yttrium (Y), gadolinium (Gd), europium (Eu), thulium (Tm), ytterbium (Yb) and terbium (Tb) ions on phagocytic activity of monocytes and granulocytes and the respiratory burst was examined. The surface functionalization of <10-nm NPs was performed according to our variation of patent pending ligand exchange method that resulted in meso-2,3-dimercaptosuccinic acid (DMSA) molecules on their surface. Y-core-based NCs were doped with Eu ions, which enabled them to be excited with UV light wavelengths. Cultures of human peripheral blood (n = 8) were in vitro treated with five different concentrations of eight NPs for 24 h. In summary, neither type of nanoparticles is found toxic with respect to conducted test; however, some cause toxic effects (they have statistically significant deviations compared to reference) in some selected doses tested. Both core types of NPs (Y-core and Gd-core) impaired the phagocytic activity of monocytes the strongest, having minimal or none whatsoever influence on granulocytes and respiratory burst of phagocytic cells. The lowest toxicity was observed in Gd-core, Yb, Tm dopants and near-infrared nanoparticles. Clear dose-dependent effect of NPs on phagocytic activity of leukocytes and respiratory burst of cells was observed for limited number of samples.

  14. The effect of core and lanthanide ion dopants in sodium fluoride-based nanocrystals on phagocytic activity of human blood leukocytes

    Science.gov (United States)

    Sojka, Bartlomiej; Liskova, Aurelia; Kuricova, Miroslava; Banski, Mateusz; Misiewicz, Jan; Dusinska, Maria; Horvathova, Mira; Ilavska, Silvia; Szabova, Michaela; Rollerova, Eva; Podhorodecki, Artur; Tulinska, Jana

    2017-02-01

    Sodium fluoride-based β-NaLnF4 nanoparticles (NPs) doped with lanthanide ions are promising materials for application as luminescent markers in bio-imaging. In this work, the effect of NPs doped with yttrium (Y), gadolinium (Gd), europium (Eu), thulium (Tm), ytterbium (Yb) and terbium (Tb) ions on phagocytic activity of monocytes and granulocytes and the respiratory burst was examined. The surface functionalization of toxic with respect to conducted test; however, some cause toxic effects (they have statistically significant deviations compared to reference) in some selected doses tested. Both core types of NPs (Y-core and Gd-core) impaired the phagocytic activity of monocytes the strongest, having minimal or none whatsoever influence on granulocytes and respiratory burst of phagocytic cells. The lowest toxicity was observed in Gd-core, Yb, Tm dopants and near-infrared nanoparticles. Clear dose-dependent effect of NPs on phagocytic activity of leukocytes and respiratory burst of cells was observed for limited number of samples.

  15. The effect of core and lanthanide ion dopants in sodium fluoride-based nanocrystals on phagocytic activity of human blood leukocytes

    Energy Technology Data Exchange (ETDEWEB)

    Sojka, Bartlomiej [Wroclaw University of Science and Technology, Department of Experimental Physics (Poland); Liskova, Aurelia; Kuricova, Miroslava [Slovak Medical University, Medical Faculty, Department of Immunology and Immunotoxicology (Slovakia); Banski, Mateusz; Misiewicz, Jan [Wroclaw University of Science and Technology, Department of Experimental Physics (Poland); Dusinska, Maria [Norwegian Institute for Air Research, Health Effects Laboratory, Department of Environmental Chemistry (Norway); Horvathova, Mira; Ilavska, Silvia; Szabova, Michaela [Slovak Medical University, Medical Faculty, Department of Immunology and Immunotoxicology (Slovakia); Rollerova, Eva [Slovak Medical University, Faculty of Public Health, Department of Toxicology (Slovakia); Podhorodecki, Artur, E-mail: artur.p.podhorodecki@pwr.edu.pl [Wroclaw University of Science and Technology, Department of Experimental Physics (Poland); Tulinska, Jana, E-mail: jana.tulinska@szu.sk [Slovak Medical University, Medical Faculty, Department of Immunology and Immunotoxicology (Slovakia)

    2017-02-15

    Sodium fluoride-based β-NaLnF4 nanoparticles (NPs) doped with lanthanide ions are promising materials for application as luminescent markers in bio-imaging. In this work, the effect of NPs doped with yttrium (Y), gadolinium (Gd), europium (Eu), thulium (Tm), ytterbium (Yb) and terbium (Tb) ions on phagocytic activity of monocytes and granulocytes and the respiratory burst was examined. The surface functionalization of <10-nm NPs was performed according to our variation of patent pending ligand exchange method that resulted in meso-2,3-dimercaptosuccinic acid (DMSA) molecules on their surface. Y-core-based NCs were doped with Eu ions, which enabled them to be excited with UV light wavelengths. Cultures of human peripheral blood (n = 8) were in vitro treated with five different concentrations of eight NPs for 24 h. In summary, neither type of nanoparticles is found toxic with respect to conducted test; however, some cause toxic effects (they have statistically significant deviations compared to reference) in some selected doses tested. Both core types of NPs (Y-core and Gd-core) impaired the phagocytic activity of monocytes the strongest, having minimal or none whatsoever influence on granulocytes and respiratory burst of phagocytic cells. The lowest toxicity was observed in Gd-core, Yb, Tm dopants and near-infrared nanoparticles. Clear dose-dependent effect of NPs on phagocytic activity of leukocytes and respiratory burst of cells was observed for limited number of samples.

  16. Synthesis, Structure, and Magnetism of Tris(amide) {Ln[N(SiMe3)2]3}1- Complexes of the Non-Traditional +2 Lanthanide Ions.

    Science.gov (United States)

    Ryan, Austin Jack; Darago, Lucy E; Balasubramini, Sree Ganesh; Chen, Guo P; Ziller, Joseph W; Furche, Filipp; Long, Jeffrey R; Evans, William J

    2018-02-28

    A new series of Ln2+ complexes has been synthesized that overturns two previous generalizations in rare-earth metal reduction chemistry: that amide ligands do not form isolable complexes of the highly-reducing non-traditional Ln2+ ions and that yttrium is a good model for the late lanthanides in these reductive reactions. Reduction of Ln(NR2)3 (R = SiMe3) complexes in THF under Ar with M = K or Rb in the presence of 2.2.2-cryptand (crypt) forms crystallographically-characterizable [M(crypt)][Ln(NR2)3] complexes not only for the traditional Tm2+ ion and the configurational crossover ions, Nd2+ and Dy2+, but also for the non-traditional Gd2+, Tb2+, Ho2+, and Er2+ ions. Crystallographic data as well as UV-visible, magnetic susceptibility, and density functional theory studies are consistent with the accessibility of 4fn5d1 configurations for Ln2+ ions in this tris(silylamide) ligand environment. The Dy2+ complex, [K(crypt)][Dy(NR2)3], has a higher magnetic moment than previously observed for any monometallic complex: 11.67 µB. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Recovery of yttrium from fluorescent powder of cathode ray tube, CRT: Zn removal by sulphide precipitation

    International Nuclear Information System (INIS)

    Innocenzi, Valentina; De Michelis, Ida; Ferella, Francesco; Beolchini, Francesca; Kopacek, Bernd; Vegliò, Francesco

    2013-01-01

    Highlights: • Treatment of fluorescent powder of CRT waste. • Factorial experimental designs to study acid leaching of fluorescent powder and the purification of leach liquors. • Recover of yttrium by precipitation using oxalic acid. • Suitable flowsheet to recover yttrium from fluorescent powder. - Abstract: This work is focused on the recovery of yttrium and zinc from fluorescent powder of cathode ray tube (CRT). Metals are extracted by sulphuric acid in the presence of hydrogen peroxide. Leaching tests are carried out according to a 2 2 full factorial plan and the highest extraction yields for yttrium and zinc equal to 100% are observed under the following conditions: 3 M of sulphuric acid, 10% v/v of H 2 O 2 concentrated solution at 30% v/v, 10% w/w pulp density, 70 °C and 3 h of reaction. Two series of precipitation tests for zinc are carried out: a 2 2 full factorial design and a completely randomized factorial design. In these series the factors investigated are pH of solution during the precipitation and the amount of sodium sulphide added to precipitate zinc sulphide. The data of these tests are used to describe two empirical mathematical models for zinc and yttrium precipitation yields by regression analysis. The highest precipitation yields for zinc are obtained under the following conditions: pH equal to 2–2.5% and 10–12% v/v of Na 2 S concentrated solution at 10% w/v. In these conditions the coprecipitation of yttrium is of 15–20%. Finally further yttrium precipitation experiments by oxalic acid on the residual solutions, after removing of zinc, show that yttrium could be recovered and calcined to obtain the final product as yttrium oxide. The achieved results allow to propose a CRT recycling process based on leaching of fluorescent powder from cathode ray tube and recovery of yttrium oxide after removing of zinc by precipitation. The final recovery of yttrium is 75–80%

  18. Recovery of yttrium from fluorescent powder of cathode ray tube, CRT: Zn removal by sulphide precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Innocenzi, Valentina, E-mail: valentina.innocenzi1@univaq.it [Department of Industrial Engineering and Information and Economy, University of L’Aquila, Via Giovanni Gronchi n.18, Nucleo Ind.le di Pile, 67100 L’Aquila (Italy); De Michelis, Ida; Ferella, Francesco [Department of Industrial Engineering and Information and Economy, University of L’Aquila, Via Giovanni Gronchi n.18, Nucleo Ind.le di Pile, 67100 L’Aquila (Italy); Beolchini, Francesca [Department of Marine Sciences, Polytechnic Institute of Marche, Via Brecce Bianche, 60131 Ancona (Italy); Kopacek, Bernd [SAT, Austrian Society for Systems Engineering and Automation, Gurkasse 43/2, A-1140 Vienna (Austria); Vegliò, Francesco [Department of Industrial Engineering and Information and Economy, University of L’Aquila, Via Giovanni Gronchi n.18, Nucleo Ind.le di Pile, 67100 L’Aquila (Italy)

    2013-11-15

    Highlights: • Treatment of fluorescent powder of CRT waste. • Factorial experimental designs to study acid leaching of fluorescent powder and the purification of leach liquors. • Recover of yttrium by precipitation using oxalic acid. • Suitable flowsheet to recover yttrium from fluorescent powder. - Abstract: This work is focused on the recovery of yttrium and zinc from fluorescent powder of cathode ray tube (CRT). Metals are extracted by sulphuric acid in the presence of hydrogen peroxide. Leaching tests are carried out according to a 2{sup 2} full factorial plan and the highest extraction yields for yttrium and zinc equal to 100% are observed under the following conditions: 3 M of sulphuric acid, 10% v/v of H{sub 2}O{sub 2} concentrated solution at 30% v/v, 10% w/w pulp density, 70 °C and 3 h of reaction. Two series of precipitation tests for zinc are carried out: a 2{sup 2} full factorial design and a completely randomized factorial design. In these series the factors investigated are pH of solution during the precipitation and the amount of sodium sulphide added to precipitate zinc sulphide. The data of these tests are used to describe two empirical mathematical models for zinc and yttrium precipitation yields by regression analysis. The highest precipitation yields for zinc are obtained under the following conditions: pH equal to 2–2.5% and 10–12% v/v of Na{sub 2}S concentrated solution at 10% w/v. In these conditions the coprecipitation of yttrium is of 15–20%. Finally further yttrium precipitation experiments by oxalic acid on the residual solutions, after removing of zinc, show that yttrium could be recovered and calcined to obtain the final product as yttrium oxide. The achieved results allow to propose a CRT recycling process based on leaching of fluorescent powder from cathode ray tube and recovery of yttrium oxide after removing of zinc by precipitation. The final recovery of yttrium is 75–80%.

  19. Synthesis of yttrium silicate luminescent materials by sol-gel method

    International Nuclear Information System (INIS)

    Arkhipov, D.V.; Vasina, O.Yu.; Popovich, N.V.; Galaktionov, S.S.; Soshchin, N.P.

    1996-01-01

    Several yttrium-silicate composition with Y 2 O 3 content within 44-56% have been synthesized. it is ascertained that employment of sol-gel technique permits preparation of luminescent materials on yttrium silicate basis, which compare favourably with bath-produced specimens. The influence of phase composition of sol-gel phosphors on basic performance indices: intensity and luminescence spectrum, has been analyzed

  20. Radiation protection data sheets for the use of Strontium 90-Yttrium 90 in unsealed sources

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This radiation protection data sheet is intended for supervisors and staff in the different medical, hospital, pharmaceutical, university and industrial laboratories and departments where Strontium 90-Yttrium 90 is handled, and also for all those involved in risk prevention in this field. It provides essential data on radiation protection measures during the use of Strontium 90-Yttrium 90 in unsealed sources: physical characteristics, risk assessment, administrative procedures, recommendations, regulations and bibliography

  1. Temperature effect on elastic properties of yttrium ferrite garnet Y3Fe5O12

    International Nuclear Information System (INIS)

    Burenkov, Yu.A.; Nikanorov, S.P.

    2002-01-01

    One studied temperature dependence of all independent elastic constants describing comprehensively elastic anisotropy of yttrium ferrite garnet within temperature wide range covering T c . One measured the Young modules for [100] and [110] crystallographic directions and the module of shift for [100] direction of specially pure single crystal of yttrium ferrite garnet within 20-600 deg C temperature range. One analyzed behavior of elastic modules and of elastic anisotropy factor near the critical temperature of magnetic phase transition [ru

  2. Quantitative description of yttrium aluminate ceramic composition by means of Er+3 microluminescence spectrum

    Science.gov (United States)

    Videla, F. A.; Tejerina, M. R.; Moreira-Osorio, L.; Conconi, M. S.; Orzi, D. J. O.; Flores, T.; Ponce, L. V.; Bilmes, G. M.; Torchia, G. A.

    2018-05-01

    The composition of erbium-doped yttrium aluminate ceramics was analyzed by means of confocal luminescence spectroscopy, EDX, and X-ray diffraction. A well-defined linear correlation was found between a proposed estimator computed from the luminescence spectrum and the proportion of ceramic phases coexisting in different samples. This result shows the feasibility of using erbium luminescence spectroscopy to perform a quantitative determination of different phases of yttrium aluminates within a micrometric region in nanograined ceramics.

  3. Structural and magnetic properties of yttrium iron garnet (YIG) and yttrium aluminum iron garnet (YAIG) nanoferrites prepared by microemulsion method

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, Majid Niaz, E-mail: majidniazakhtar@ciitlahore.edu.pk [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Bakar Sulong, Abu [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Khan, Muhammad Azhar [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Ahmad, Mukhtar [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Murtaza, Ghulam [Centre for Advanced Studies in Physics, G.C. University, Lahore, Pakistan" f Department of Mechanical Engineering, COMSATS Institute of Information Technology Sahiwal Pakistan (Pakistan); Raza, M.R. [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Department of Mechanical Engineering, COMSATS Institute of Information Technology Sahiwal (Pakistan); Raza, R.; Saleem, M. [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Kashif, M. [Department of Physics, Govt. College University Faisalabad (Pakistan)

    2016-03-01

    Yttrium iron garnet (YIG) and yttrium aluminum iron garnet (YAIG) nanoferrite samples were synthesized by microemulsion method. The effect of sintering was examined by heating the samples at 900, 1000, and 1100 °C. The YIG and YAIG samples were then characterized using X-ray diffraction and field-emission scanning electron microscopy. Static and dynamic magnetic properties were measured by evaluating initial permeability, Q factor, and vibrating sample magnetometry properties of YIG and YAIG samples. YIG samples sintered at 1100 °C showed higher initial permeability and Q factor compared with YAIG samples. However, hysteresis loops also showed variations in the saturation magnetization, remanence, and coercivity of YIG and YAIG samples sintered at 900, 1000, and 1100 °C. The observed magnetic parameter such as saturation magnetization, coercivity and initial permeability are strongly affected by increasing temperature. The saturation magnetization and coercivity of YIG and YAIG nanoferrites were found in the range 11.56–19.92 emu/g and 7.30–87.70 Oe respectively. Furthermore, the decreasing trends in the static and magnetic properties of YAIG samples may be due to the introduction of Al ions in the YIG crystal lattice. Thus, YIG and YAIG sintered at 1100 °C can be used for wide-ranging frequency applications. - Highlights: • Static and dynamic magnetic properties of YIG and YAIG nanoferrites were determined. • Saturation magnetization, Q and initial permeability increased in YIG nanoferites. • Possible use of these nanoferrites for sensing and switching applications.

  4. Luminescent hybrid lanthanide sulfates and lanthanide sulfonate-carboxylates with 1,10-phenanthroline involving in-situ oxidation of 2-mercaptonbenzoic acid

    Science.gov (United States)

    Zhong, Jie-Cen; Wan, Fang; Sun, Yan-Qiong; Chen, Yi-Ping

    2015-01-01

    A series of lanthanide sulfates and lanthanide sulfonate-carboxylates, [Ln2(phen)2(SO4)3(H2O)2]n (I:Ln=Nd(1a), Sm(1b), Eu(1c), phen=1,10-phenanthroline) and [Ln(phen)(2-SBA)(BZA)]n (II: Ln=Sm(2a), Eu(2b), Dy(2c), 2-SBA=2-sulfobenzoate, BZA=benzoate) have been hydrothermally synthesized from lanthanide oxide, 2-mercaptonbenzoic acid with phen as auxiliary ligand and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, TG analyses and luminescence spectroscopy. Interestingly, SO4 2 - anions in I came from the in situ deep oxidation of thiol groups of 2-mercaptonbenzoic acid while 2-sulfobenzoate and benzoate ligands in II from the middle oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. Compounds I are organic-inorganic hybrid lanthanide sulfates, which have rare one-dimensional column-like structures. Complexes II are binuclear lanthanide sulfonate-carboxylates with 2-sulfobenzoate and benzoate as bridges and 1,10-phenanthroline as terminal. Photoluminescence studies reveal that complexes I and II exhibit strong lanthanide characteristic emission bands in the solid state at room temperature.

  5. N-m-nitrocinnamoylphenylhydroxyl-amine as reagent for amperometric determination of yttrium

    International Nuclear Information System (INIS)

    Oliferenko, G.L.; Gallaj, Z.A.; Sheina, N.M.; Shvedene, N.V.

    1983-01-01

    Possibility of using organic reagent of unsaturated N-arylsubstituted derivatives class of hydroxamic acids N-m-nitrocinnamoyl phenylhydroxylamire (NCPHA) for amperometric titration of yttrium using indication of e.t.p. by current of reagent oxidation on graphite electrode is investigated. Metal and the NCPHA form difficultly soluble complex with ratio of yttrium to the NCPHA, which is equal to 1:3. Buffer mixtures of 0.1MNH 3 +0.1MCH 3 COOH composis tion with pH 6.3-7.5 are optimal background solutions for amperometric titration of yttrium. The proposed method permits to determine 10-600 μkg of yttrium in the volume of 10 ml. Effect of the series of strange elements on titration of yttrium with NCPHA (Ca, Mg, Mn (2), Al, CU (2), Fe (3) REE and others) is studied. The developed method is used for yttrium determination in luminophores of Casub(n)-- Ysub(m)Fsub(z)xMn(2) (1-10%) composition

  6. The behaviour of selected yttrium containing bioactive glass microspheres in simulated body environments.

    Science.gov (United States)

    Cacaina, D; Ylänen, H; Simon, S; Hupa, M

    2008-03-01

    The study aims at the manufacture and investigation of biodegradable glass microspheres incorporated with yttrium potentially useful for radionuclide therapy of cancer. The glass microspheres in the SiO2-Na2O-P2O5-CaO-K2O-MgO system containing yttrium were prepared by conventional melting and flame spheroidization. The behaviour of the yttrium silicate glass microspheres was investigated under in vitro conditions using simulated body fluid (SBF) and Tris buffer solution (TBS), for different periods of time, according to half-life time of the Y-90. The local structure of the glasses and the effect of yttrium on the biodegradability process were evaluated by Fourier Transform Infrared (FT-IR) spectroscopy and Back Scattered Electron Imaging of Scanning Electron Microscopy (BEI-SEM) equipped with Energy Dispersive X-ray (EDX) analysis. UV-VIS spectrometry and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used for analyzing the release behaviour of silica and yttrium in the two used solutions. The results indicate that the addition of yttrium to a bioactive glass increases its structural stability which therefore, induced a different behaviour of the glasses in simulated body environments.

  7. Size-dependent cytotoxicity of yttrium oxide nanoparticles on primary osteoblasts in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Guoqiang, E-mail: zhougq1982@163.com; Li, Yunfei; Ma, Yanyan; Liu, Zhu; Cao, Lili; Wang, Da; Liu, Sudan; Xu, Wenshi; Wang, Wenying [Hebei University, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science (China)

    2016-05-15

    Yttrium oxide nanoparticles are an excellent host material for the rare earth metals and have high luminescence efficiency providing a potential application in photodynamic therapy and biological imaging. In this study, the effects of yttrium oxide nanoparticles with four different sizes were investigated using primary osteoblasts in vitro. The results demonstrated that the cytotoxicity generated by yttrium oxide nanoparticles depended on the particle size, and smaller particles possessed higher toxicological effects. For the purpose to elucidate the relationship between reactive oxygen species generation and cell damage, cytomembrane integrity, intracellular reactive oxygen species level, mitochondrial membrane potential, cell apoptosis rate, and activity of caspase-3 in cells were then measured. Increased reactive oxygen species level was also observed in a size-dependent way. Thus, our data demonstrated that exposure to yttrium oxide nanoparticles resulted in a size-dependent cytotoxicity in cultured primary osteoblasts, and reactive oxygen species generation should be one possible damage pathway for the toxicological effects produced by yttrium oxide particles. The results may provide useful information for more rational applications of yttrium oxide nanoparticles in the future.

  8. Increasing lanthanide luminescence by use of the RETEL effect.

    Science.gov (United States)

    Leif, Robert C; Vallarino, Lidia M; Becker, Margie C; Yang, Sean

    2006-08-01

    Luminescent lanthanide complexes produce emissions with the narrowest-known width at half maximum; however, their significant use in cytometry required an increase in luminescence intensity. The companion review, Leif et al., Cytometry 2006;69A:767-778, described a new technique for the enhancement of lanthanide luminescence, the Resonance Energy Transfer Enhanced Luminescence (RETEL) effect, which increases luminescence and is compatible with standard slide microscopy. The luminescence of the europium ion macrocyclic complex, EuMac, was increased by employing the RETEL effect. After adding the nonluminescent gadolinium ion complex of the thenoyltrifluoroacetonate (TTFA) ligand or the sodium salt of TTFA in ethanol solution, the EuMac-labeled sample was allowed to dry. Both a conventional arc lamp and a time-gated UV LED served as light sources for microscopic imaging. The emission intensity was measured with a CCD camera. Multiple time-gated images were summed with special software to permit analysis and effective presentation of the final image. With the RETEL effect, the luminescence of the EuMac-streptavidin conjugate increased at least six-fold upon drying. Nuclei of apoptotic cells were stained with DAPI and tailed with 5BrdUrd to which a EuMac-anti-5BrdU conjugate was subsequently attached. Time-gated images showed the long-lived EuMac luminescence but did not show the short-lived DAPI fluorescence. Imaging of DNA-synthesizing cells with an arc lamp showed that both S phase and apoptotic cells were labeled, and that their labeling patterns were different. The images of the luminescent EuMac and fluorescent DAPI were combined to produce a color image on a white background. This combination of simple chemistry, instrumentation, and presentation should make possible the inexpensive use of the lanthanide macrocycles, Quantum Dyes, as molecular diagnostics for cytological and histopathological microscopic imaging. (c) 2006 International Society for Analytical

  9. Complexes of light lanthanides with 2,4-dimethoxybenzoic acid

    Directory of Open Access Journals (Sweden)

    WIESLAWA FERENC

    2000-01-01

    Full Text Available The complexes of light lanthanides with 2,4-dimethoxybenzoic acid of the formula: Ln(C9H9O43·nH2O where Ln = La(III, Ce(III, Pr(III, Nd(III, Sm(III, Eu(III, Gd(IIII, and n = 3 for La(III, Gd(III, n = 2 for Sm(III, Eu(III, and n = 0 for Ce(III, Pr(III, Nd(III have been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric studies and X-ray diffraction measurements. The complexes have colours typical for Ln3+ ions (La, Ce, Eu, Gd-white, Sm-cream, Pr-green, Nd-violet. The carboxylate group in these complexes is a symmetrical, bidentate, chelating ligand. They are crystalline compounds characterized by various symmetry. On heating in air to 1273 K the 2,4-dimethoxybenzoates of the light lanthanides decompose in various ways. The hydrated complexes decompose in two or three steps while those of anhydrous ones only in one or two. The trihydrate of lanthanum 2,4-dimethoxybenzoate first dehydrates to form the anhydrous salt, which then decomposes to La2O3via the intermediate formation of La2O2CO3. The hydrates of Sm(III, Eu(III, Gd(III decompose in two stages. First, they dehydrate forming the anhydrous salts, which then decompose directly to the oxides of the respective metals. The anhydrous complexes of Ce(III, Pr(III decompose in one step, while that of Nd(III in two. The solubilities of the 2,4-dimethoxybenzoates of the light lanthanides in water and ethanol at 293 K are in the order of: 10-3 mol dm-3 and 10-4-10-3 mol dm-3, respectively.

  10. Mixed ligand lanthanide complexes with dipivaloylmethane and acetic acid

    International Nuclear Information System (INIS)

    Lyu Fehnkhua; Kuz'mina, N.P.; Mazo, G.N.; Martynenko, L.I.

    1995-01-01

    Methods of elemental, X-ray phase, thermal analyses and infrared spectroscopy were used to characterize solid products, formed in MDpm 3 -HAcet-H-hexane systems (M = Pr, Nd, Eu, Gd, Ho, Er, Yb, HDpm -dipivaloylmethane, HAcet - acetic acid). It was established that prepared mixed ligand complexes (MLC) had MDpm 2 Acet composition for all studied rare earths. Differenced in properties of cerium and yttrium rare earths are manifested in processes of MLC thermal dissociation, proceeding at low pressure and 170 deg C. 6 refs., 4 tabs

  11. Recent progress in actinide and lanthanide solvent extraction

    International Nuclear Information System (INIS)

    Musikas, C.; Hubert, H.; Benjelloun, N.; Vitorge, P.; Bonnin, M.; Forchioni, A.; Chachaty, C.

    1983-04-01

    Work in progress on actinide solvent extraction is briefly reviewed in this paper. 1 H and 31 P NMR are used to elucidate several fundamental unsolved problems concerning organophosphorous extractants often used in actinides extraction: determination of site of dialkylthiophosphate protonation and addition of basic phosphine oxide to dibutylthiophosphoric acid dimer. Extraction of Am III and Eu from high radioactivity level wastes by tetrasubsituted methylene diamides is investigated. Trivalent actinide-lanthanide group are separated by solvent extraction using soft donor ligand complexes which are more stable. The synergism of dinonylnaphtalene sulfonic acid (HDNNS) associated with several neutral donors like TBP, TOPO, amides are examined in the trivalent and tetravalent actinide extraction

  12. Introduction to molecular magnetism from transition metals to lanthanides

    CERN Document Server

    Benelli, Cristiano

    2015-01-01

    This first introduction to the rapidly growing field of molecular magnetism is written with Masters and PhD students in mind, while postdocs and other newcomers will also find it an extremely useful guide. Adopting a clear didactic approach, the authors cover the fundamental concepts, providing many examples and give an overview of the most important techniques and key applications. Although the focus is one lanthanide ions, thus reflecting the current research in the field, the principles and the methods equally apply to other systems. The result is an excellent textbook from both a scientif

  13. Reaction between phenyl derivatives of lanthanides and carbonyl compounds

    International Nuclear Information System (INIS)

    Sigalov, A.B.; Petrov, Eh.S.; Rybakova, L.F.; Beletskaya, I.P.

    1983-01-01

    Reactions of PhLnI (Ln=Yb, Eu, Sm, Ce) with α, β-unsaturated ketons (trans-chalcone and benzalacetone) are considered as well as with 9-fluorene and benzophenone. The regioselectivity of the reaction of PhLnI addition to enones is compared with similar reactions of PhMgX and PhLi. The reaction between PhLnI and trans-chalcone proceeds regiospecifically as 1, 2-addition in contrast with reactions of PhMgI and PhLi. A new reaction of lanthanide carbinolate deoxygenation under the effect of reducers was found. The reaction product yields are presented

  14. Synthesis, characterization and reactivity of some lanthanide organometallics

    International Nuclear Information System (INIS)

    Marchal, N.

    1991-12-01

    Organo lanthanides with reactive metal-carbon bonds are obtained by direct synthesis of the metal (powder) and a hydrocarbon in ether medium, like with alkali metals. Two types of synthesis are envisaged: formation of covalent bonds by opening cycles, only biphenylene is reactive enough in regard to ytterbium and samarium, these organometallic compounds can also be prepared by the classical way, i.e. reaction of 2.2'-dilithio biphenyl on rare earth halogenides and coupling of 6.6-dimethylfulvene leading to dicyclopentadienyl compounds with Sm and Yb. The reactivity of these complexes is studied by catalysis of ethylene polymerization

  15. New strategies for the chemical separation of actinides and lanthanides

    International Nuclear Information System (INIS)

    Hudson, M.J.; Iveson, P.B.

    2002-01-01

    A general model is proposed for the effective design of ligands for partitioning. There is no doubt that the correct design of a molecule is required for the effective separation by separation of metal ions such as lanthanides(III) and actinides(III). Heterocyclic ligands with aromatic rings systems have a rich chemistry, which is only now becoming sufficiently well understood, in relation to the partitioning process. The synthesis, characterisation and structures of some chosen molecules will be introduced in order to illustrate some important features. For example, the molecule N-butyl-2-amino-4,6-di (2-pyridyl)-1,3,5-triazine (BADPTZ), which is an effective solvent extraction reagent for actinides and lanthanides, has been synthesised, characterised and its interaction with metal ions studied. The interesting and important features of this molecule will be compared with those of other heterocyclic molecules such as 2,6-bis(5-butyl-1,2,4-triazol-3-yl) pyridine (DBTZP), which is a candidate molecule for the commercial separation of actinides and lanthanide elements. Primary Coordination Sphere. One of the most critical features concerning whether a molecule is a suitable extraction reagent is the nature of the binding and co-ordination in the primary co-ordination sphere. This effect will be considered in depth for the selected heterocylic molecules. It will be shown how the bonding of the heterocyclic and nitrate ligands changes as the complete lanthanide series is traversed from lanthanum to lutetium. For effective solvent extraction, the ligand(s) should be able completely to occupy the primary co-ordination sphere of the metal ion to be extracted. Interactions in the secondary co-ordination sphere are of less importance. Inter-complex Hydrogen Bonding Interactions. Another feature that will be considered is the intermolecular binding between ligands when bound to the metal ion. Thus the intermolecular structures between complex molecules will be considered

  16. Lanthanides and actinides extraction by calixarenes containing CMPO groups

    International Nuclear Information System (INIS)

    Garcia Carrera, A.

    2001-01-01

    In the framework of the French program SPIN concerning the radioactive waste management, researches are performed to develop processes allowing the separation of long-lived radioisotopes in order to their transmutation or their specific conditioning. These studies deal with the extraction and the separation of trivalent lanthanides and actinides in acid solution. Many systems ''calixarene-diluent-aqueous phase'' are examined by extraction liquid-liquid and membrane transport. The extraction efficiency and the selectivity of the synthesized calixarene-CMPO and of the CMPO are compared with these cations, as the nitric acid extraction by these molecules. (A.L.B.)

  17. X-ray powder diffraction data on miscellaneous lanthanide compounds

    International Nuclear Information System (INIS)

    Ferguson, I.F.; Hughes, T.E.

    1978-08-01

    Recent work on neutron absorbing materials has produced various new X-ray diffraction powder patterns of compounds of the lanthanides. Various inconsistencies in previously published data have been noted, and accurate measurements have been made of the lattice parameters of the rare earth oxides Sm 2 0 3 , Eu 2 0 3 , Gd 2 0 3 which have the monoclinic rare earth type B- structure, as well as Eu0. These data are recorded for reference. The optimum conditions for obtaining X-ray powder diffraction data from europium compounds are also noted. (author)

  18. Magnetic Circular Dichroism of Porphyrin Lanthanide M3+ Complexes

    Czech Academy of Sciences Publication Activity Database

    Andrushchenko, Valery; Padula, Daniele; Zhivotova, E.; Yamamoto, S.; Bouř, Petr

    2014-01-01

    Roč. 26, č. 10 (2014), s. 655-662 ISSN 0899-0042 R&D Projects: GA ČR GA13-03978S; GA ČR GAP208/11/0105; GA MŠk(CZ) LH11033 Grant - others:GA AV ČR(CZ) M200550902 Institutional support: RVO:61388963 Keywords : magnetic circular dichroism * lanthanides * porphyrin complexes * density functional theory * sum over state computations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.886, year: 2014

  19. Status of the lanthanides and actinides in the periodic table

    International Nuclear Information System (INIS)

    Holden, N.E.

    1985-01-01

    In extended discussions and correspondence with Ekkehard Fluck, the author was made aware of a problem with the Periodic Table, i.e., which element should be shown in the main table as the representative of the lanthanide series and the actinide series. In earlier discussion, he came to the conclusion that lanthanum and actinium are not the elements which should appear, but rather lutetium and lawrencium are more appropriate for inclusion in their place. This paper will attempt to justify the reasons for the above conclusions. 4 refs

  20. Study of decomposition kinetics of volatile β-diketonates of yttrium, barium and copper in flow reactor

    International Nuclear Information System (INIS)

    Devyatykh, G.G.; Gavrishchuk, E.M.; Gibin, A.M.; Dadanov, A.Yu.; Dzyubenko, N.G.; Kaul', A.R.; Nichiporuk, R.V.; Snezhko, N.T.; Ul'yanov, A.A.

    1990-01-01

    Heterogeneous oxidative decomposition of adduct of yttrium acetylacetonate with o-phenanthroline, copper acetylacetonate and barium dipivaloylmethanate in a flow-type reactor was carried out. The basic kinetic characteristics of chemical precipitation processes of films of yttrium, copper and barium oxides, which are components of high-temperature superconductors, were obtained. The values of activation energy of precipitation process of yttrium, copper and barium oxides constituted 76±10, 108±15, 81±12 (t 600 deg C) respectively

  1. Study of strength properties of semi-finished products from economically alloyed high-strength aluminium-scandium alloys for application in automobile transport and shipbuilding

    Science.gov (United States)

    Baranov, Vladimir; Sidelnikov, Sergey; Zenkin, Evgeny; Frolov, Viktor; Voroshilov, Denis; Yakivyuk, Olga; Konstantinov, Igor; Sokolov, Ruslan; Belokonova, Irina

    2018-04-01

    The results of a study on the strength of rolled products from aluminium alloys doped with scandium under various processing conditions of hot and cold rolling are presented. The regularities of metal flow and the level of strength of deformed semi-finished products from aluminum-scandium alloys are established, depending on the total degree of deformation and the various modes of single reduction during rolling. It is shown that when using one heating of a cast billet to obtain high-quality semi-finished products, the temperature during the rolling process should not be lower than 350-370°, and the total degree of deformation does not exceed 50-60%. It was found that the semi-finished products from alloys with a content of scandium in the range 0.11-0.12% in the deformed state had elevated values of ultimate tensile strength and yield strength of the metal, which allows them to be recommended for industrial production of sheet metal products.

  2. Development of methods for the selective separation of scandium, zirconium and tin for radiopharmaceutical applications; Entwicklung von Methoden zur selektiven Trennung von Scandium, Zirkonium und Zinn fuer radiopharmazeutische Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Dirks-Fandrei, Carina

    2014-07-01

    The subject of the present work is the development of fast and highly selective methods for the separation and purification of scandium, zirconium and tin radionuclides from potential target materials for use in nuclear medicine. A number of selected resins (TrisKem International) were first characterized with respect to their extraction behaviour towards a large number of cations. Characterization studies were performed in batch experiments by determination of weight distribution ratios D{sub w} and further the influence of interferences on the uptake of these elements was evaluated. Weight distribution ratios were determined in different acids and acid concentrations with main focus on scandium, tin or zirconium. The interference of macro amounts of Calcium and Ti on the Sc extraction was evaluated as well as the interference of macro amounts of Y on the Zr extraction. Best suited uptake conditions were found for Scandium on DGA were determined to be 2.5 M HNO{sub 3} for Ti-Targets and 0.1 M HNO{sub 3} for Calcium-Targets. Otherwise it is also possible to extract Sc with TRU Resin. High uptakes were obtained at 2.5 M HNO{sub 3} for simulated Ti- and Calcium-targets. Separation methods were developed using elution studies; employed conditions were chosen according to parameters evaluated in the batch-experiment. The developed methods allowed separating Sc very rapidly in high purity very rapidly from Ti- or Calcium-targets. For Zr a separation method based on UTEVA Resin has been developed. Following results of batch experiments simulated Y-target solution were loaded onto a UTEVA resin column from 6 M HNO{sub 3}; the elution of Zr could be performed in 0.01 M oxalic acid. Decontamination factors in the order of 10{sup 4}-10{sup 5} could be obtained applying the developed method; the method thus allowed separating Zr in a high purity. Initial testing of a method for the separation of Sn from Cd targets based on the use of TBP Resin showed that the TBP resin seems

  3. Efficient Separation of Lanthanides Using Poly (Styrene-Divinyl Benzene) Aminated Anion Exchanger

    International Nuclear Information System (INIS)

    Borai, E.H.; Hassan, R.S.; El- Dessouky, M.I.; Ghonem, A.

    2008-01-01

    New chromatographic method was developed for the determination and separation of lanthanides using AS4A anionic column. The behavior of the column towards lanthanides was studied through many parameters, From the data obtained it is found that, affinity of the column toward investigated ions increase by increasing eluent concentration and it decrease retention factors. With the two investigated eluent (oxalic and citric acids), elution order for lanthanide elements was obtained in their atomic number from La to Lu. Retention times and retention orders obtained at these conditions clearly show that, lanthanides in AS4A are displaced according to anion exchange mechanism. More over separation of lanthanides using AS4A was studied using isocratic and gradient elution programs. Light and the first intermediate lanthanide elements were separated successfully by applying a gradient program containing 70% oxalic acid (100 mM) and 30% water. The problem of separation for heavy and the last intermediate lanthanide elements was solved using 100 mM alpha hydroxy isobutyric acid (α-HIBA)

  4. Surface characterization of low-temperature grown yttrium oxide

    Science.gov (United States)

    Krawczyk, Mirosław; Lisowski, Wojciech; Pisarek, Marcin; Nikiforow, Kostiantyn; Jablonski, Aleksander

    2018-04-01

    The step-by-step growth of yttrium oxide layer was controlled in situ using X-ray photoelectron spectroscopy (XPS). The O/Y atomic concentration (AC) ratio in the surface layer of finally oxidized Y substrate was found to be equal to 1.48. The as-grown yttrium oxide layers were then analyzed ex situ using combination of Auger electron spectroscopy (AES), elastic-peak electron spectroscopy (EPES) and scanning electron microscopy (SEM) in order to characterize their surface chemical composition, electron transport phenomena and surface morphology. Prior to EPES measurements, the Y oxide surface was pre-sputtered by 3 kV argon ions, and the resulting AES-derived composition was found to be Y0.383O0.465C0.152 (O/Y AC ratio of 1.21). The SEM images revealed different surface morphology of sample before and after Ar sputtering. The oxide precipitates were observed on the top of un-sputtered Y oxide layer, whereas the oxide growth at the Ar ion-sputtered surface proceeded along defects lines normal to the layer plane. The inelastic mean free path (IMFP) characterizing electron transport was evaluated as a function of energy in the range of 0.5-2 keV from the EPES method. Two reference materials (Ni and Au) were used in these measurements. Experimental IMFPs determined for the Y0.383O0.465C0.152 and Y2O3 surface compositions, λ, were uncorrected for surface excitations and approximated by the simple function λ = kEp at electron energies E between 500 eV and 2000 eV, where k and p were fitted parameters. These values were also compared with IMFPs resulting from the TPP-2 M predictive equation for both oxide compositions. The fitted functions were found to be reasonably consistent with the measured and predicted IMFPs. In both cases, the average value of the mean percentage deviation from the fits varied between 5% and 37%. The IMFPs measured for Y0.383O0.465C0.152 surface composition were found to be similar to the IMFPs for Y2O3.

  5. Optimized conditions for chelation of yttrium-90-DOTA immunoconjugates.

    Science.gov (United States)

    Kukis, D L; DeNardo, S J; DeNardo, G L; O'Donnell, R T; Meares, C F

    1998-12-01

    Radioimmunotherapy (RIT) with 90Y-labeled immunoconjugates has shown promise in clinical trials. The macrocyclic chelating agent 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA) binds 90Y with extraordinary stability, minimizing the toxicity of 90Y-DOTA immunoconjugates arising from loss of 90Y to bone. However, reported 90Y-DOTA immunoconjugate product yields have been typically only BAD) was conjugated to the monoclonal antibody Lym-1 via 2-iminothiolane (2IT). The immunoconjugate product, 2IT-BAD-Lym-1, was labeled in excess yttrium in various buffers over a range of concentrations and pH. Kinetic studies were performed in selected buffers to estimate radiolabeling reaction times under prospective radiopharmacy labeling conditions. The effect of temperature on reaction kinetics was examined. Optimal radiolabeling conditions were identified and used in eight radiolabeling experiments with 2IT-BAD-Lym-1 and a second immunoconjugate, DOTA-peptide-chimeric L6, with 248-492 MBq (6.7-13.3 mCi) of 90Y. Ammonium acetate buffer (0.5 M) was associated with the highest uptake of yttrium. On the basis of kinetic data, the time required to chelate 94% of 90Y (four half-times) under prospective radiopharmacy labeling conditions in 0.5 M ammonium acetate was 17-148 min at pH 6.5, but it was only 1-10 min at pH 7.5. Raising the reaction temperature from 25 degrees C to 37 degrees C markedly increased the chelation rate. Optimal radiolabeling conditions were identified as: 30-min reaction time, 0.5 M ammonium acetate buffer, pH 7-7.5 and 37 degrees C. In eight labeling experiments under optimal conditions, a mean product yield (+/- s.d.) of 91%+/-8% was achieved, comparable to iodination yields. The specific activity of final products was 74-130 MBq (2.0-3.5 mCi) of 90Y per mg of monoclonal antibody. The immunoreactivity of 90Y-labeled immunoconjugates was 100%+/-11%. The optimization of 90Y-DOTA chelation conditions represents an important advance in 90Y RIT

  6. Treatment of persistent knee effusions with Yttrium 90

    International Nuclear Information System (INIS)

    Bouyoucef, S.E.; Drahmoune, R.; Mechken, F.; Amimour, A.; Hanni-Haddam, F.; Abtroun, F.; Sellah, M.; Mansouri, B.

    2002-01-01

    Yttrium 90 intra-articular injection is used in persisting active joint of the knee, where medication has failed to resolve chronic inflammation. The effective dose delivered to the synovia is linked to Y 90 activity and depends on the size of the joint space, the synovial structure and thickness and the inflammatory activity of the synovitis. The amount of the injected activity of Y90 was estimated according the volume effusion in 28 pathologic knee of 18 patients aged 18 years and more (mean age 46 years). All patients have persistent knee effusions and most of them have rheumatoid arthritis but others had ankylosing spondylitis, Behcet disease, psoriatic arthritis. According the radiological classification of Steinbrocker, 19 pathological knees were in stage 1, 5 in stage 2 and 4 in stage 3. The mean value of the monthly removed volume of the synovial liquid from the pathological knee was determined during the last month preceding the radiosynoviorthesis and four groups were identified: V0 no evidence of effusion liquid, 0 ml 100ml. The activity of Y 90 was estimated in order to obtain a total of 100 Gray in the envelope of 3 spherical phantoms with the same range of volume as defined above. The lowest activity of Y90, 111 MBq (3mCi) was determined for V0 according a mean value of standard sizes of knees. An activity of 18 MBq (0.5mCi) was added for each stage of 50 ml, so 129 MBq (3.5 mCi) for G1, 148 MBq (4 mCi) for G2 and 166 MBq (4.5 mCi) for G3. Efficacy of Y90 treatment was clinically assessed in all patients according to three parameters: pain, hydrarthrosis and range of joint movement at 1, 3, 6 and 12 months. The results were excellent in 13 knees and good in 9 and for most of them the efficacy of Y 90 was observed after 6 months. The results were less good in 3 knees but with an initial good evolution for all at 1 month. For 4 knees, the efficacy of Y 90 was bad. Although the small number of patients, these results show a high rate, 75%, of successful

  7. Electromotive force measurement of lanthanides in Bi solution

    International Nuclear Information System (INIS)

    Sheng, Jiawei; Yamana, Hajimu; Moriyama, Hirotake

    2000-01-01

    The thermodynamic properties of Tb, Dy and Ho dissolved in liquid Bi were determined by the electromotive force (EMF) measurement method. The EMF of the following galvanic cell was measured in the range of 500-800degC over a wide range of solute concentration. Ln(solid)|KCl-LiCl|Ln-Bi (solution) There was observed a linear relationship between the EMFs and the lanthanide (Ln) concentrations in liquid Bi phase at a constant temperature, which agreed with the Nernst's equation. The obtained activity coefficients of lanthanides in liquid Bi solution were almost constant at a fixed temperature condition. Temperature effects on the activity coefficients could be expressed by the following equation: log γ=a+b/T, where a and b are experimental constants which correspond to the entropy and enthalpy of the formation of Ln-Bi compound in the melt, respectively. The thermodynamic quantities obtained were discussed in terms of their systematics along the 4f series. (author)

  8. Lanthanide-based fluorescent tracers in complex media

    International Nuclear Information System (INIS)

    Brichart, Thomas

    2014-01-01

    Tracers are objects allowing the determination of the position or the distribution of a product; tracers are currently used in a great variety of domains. Despite the fact that each field has it's own specifications, it is possible to find tracers in medicine (contrast agents), anti-counterfeiting or geological exploration. We have developed lanthanide complex tracers for oil field injection waters. Those tracers, derived from the DOTA, have been detected at concentration lower than 1 ppb, thanks to a simple and compact apparatus. This detection has been made possible by the use of time-resolved fluorescence spectroscopy, this technique allows us to get rid of the background noise created by the intrinsic fluorescence of oil residues that are present in production waters. We also demonstrated how we can, through a reverse microemulsion synthesis, encapsulate several different dyes inside a single nanoparticle composed of a gold core and a silica shell. We showed as well, how those particles can be used as smart tracers to gather data, such as temperature, pH, solvents, etc. inside the well. Finally the use of lanthanides and scale inhibitors properties allowed us to create a simple and fast dosing protocol of such scale inhibitors in injection waters. This dosage will then allow the quick adjustment of their concentration inside each well. (author) [fr

  9. Lanthanide-IMAC enrichment of carbohydrates and polyols.

    Science.gov (United States)

    Schemeth, Dieter; Rainer, Matthias; Messner, Christoph B; Rode, Bernd M; Bonn, Günther K

    2014-03-01

    In this study a new type of immobilized metal ion affinity chromatography resin for the enrichment of carbohydrates and polyols was synthesized by radical polymerization reaction of vinyl phosphonic acid and 1,4-butandiole dimethacrylate using azo-bis-isobutyronitrile as radical initiator. Interaction between the chelated trivalent lanthanide ions and negatively charged hydroxyl groups of carbohydrates and polyols was observed by applying high pH values. The new method was evaluated by single standard solutions, mixtures of standards, honey and a more complex extract of Cynara scolymus. The washing step was accomplished by acetonitrile in excess volumes. Elution of enriched carbohydrates was successfully performed with deionized water. The subsequent analysis was carried out with matrix-free laser desorption/ionization-time of flight mass spectrometry involving a TiO2 -coated steel target, especially suitable for the measurement of low-molecular-weight substances. Quantitative analysis of the sugar alcohol xylitol as well as the determination of the maximal loading capacity was performed by gas chromatography in conjunction with mass spectrometric detection after chemical derivatization. In a parallel approach quantum mechanical geometry optimizations were performed in order to compare the coordination behavior of various trivalent lanthanide ions. Copyright © 2013 John Wiley & Sons, Ltd.

  10. Stabilization of actinides and lanthanides in unusually high oxidation states

    International Nuclear Information System (INIS)

    Eller, P.G.; Penneman, R.A.

    1986-01-01

    Chemical environments can be chosen which stabilize actinides and lanthanides in unusually high or low oxidation states and in unusual coordination. In many cases, one can rationalize the observed species as resulting from strong charge/size influences provided by specific sites in host lattices (e.g., Tb(IV) in BaTbO 3 or Am(IV) in polytungstate anions). In other cases, the unusual species can be considered from an acid-base viewpoint (e.g., U(III) in AsF 5 /HF solution or Pu(VII) in Li 5 PuO 6 ). In still other cases, an interplay of steric and redox effects can lead to interesting comparisons (e.g., instability of double fluoride salts of Pu(V) and Pu(VI) relative to U, Np, and Am analogues). Generalized ways to rationalize compounds containing actinides and lanthanides in unusual valences (particularly high valences), including the above and numerous other examples, will form the focus of this paper. Recently developed methods for synthesizing high valent f-element fluorides using superoxidizers and superacids at low temperatures will also be described. 65 refs., 8 figs., 9 tabs

  11. Thermochemistry of selected lanthanide and actinide hydroxycarbonates and carbonates

    International Nuclear Information System (INIS)

    Merli, L.; Fuger, J.

    1996-01-01

    Lanthanide and actinide carbonates and hydroxycarbonates are, together with the hydroxides, important compounds in the problematics of high level waste disposal, since such and related compounds may appear as solid phases as a result of the interaction of the waste with natural waters. Experimental results on the stability and relationships between these compounds, particularly the hydroxycarbonates, are relatively fragmentary and arise mainly from solubility measurements, and, to a lesser extent, from enthalpy of formation determinations. We report here the enthalpies of formation of a number of well characterized hydroxycarbonates of trivalent lanthanides, namely those of neodymium, samarium, dysprosium, ytterbium, and of americium, as well as that of neodymium sesquicarbonate, using solution calorimetry in acidic media. The obtained values are discussed in the light of literature data on existing solubility and enthalpy of formation of related compounds. Our results have been obtained with a newly conceived sealed calorimeter, briefly described in the paper, in which the CO 2 produced during the dissolution reaction is maintained in solution, thus eliminating the problem of the kinetically slow evolution of the CO 2 (g) from the medium and the irregularities in the associated thermal effect. (orig.)

  12. Energetic lanthanide complexes: coordination chemistry and explosives applications

    International Nuclear Information System (INIS)

    Manner, V W; Barker, B J; Sanders, V E; Laintz, K E; Scott, B L; Preston, D N; Sandstrom, M; Reardon, B L

    2014-01-01

    Metals are generally added to organic molecular explosives in a heterogeneous composite to improve overall heat and energy release. In order to avoid creating a mixture that can vary in homogeneity, energetic organic molecules can be directly bonded to high molecular weight metals, forming a single metal complex with Angstrom-scale separation between the metal and the explosive. To probe the relationship between the structural properties of metal complexes and explosive performance, a new series of energetic lanthanide complexes has been prepared using energetic ligands such as NTO (5-nitro-2,4-dihydro-1,2,4-triazole-3-one). These are the first examples of lanthanide NTO complexes where no water is coordinated to the metal, demonstrating novel control of the coordination environment. The complexes have been characterized by X-ray crystallography, NMR and IR spectroscopies, photoluminescence, and sensitivity testing. The structural and energetic properties are discussed in the context of enhanced blast effects and detection. Cheetah calculations have been performed to fine-tune physical properties, creating a systematic method for producing explosives with 'tailor made' characteristics. These new complexes will be benchmarks for further study in the field of metalized high explosives.

  13. Enrichment of yttrium from rare earth concentrate by ammonium carbonate leaching and peroxide precipitation

    International Nuclear Information System (INIS)

    Vasconcellos, Mari E. de; Rocha, S.M.R. da; Pedreira, W.R.; Queiroz S, Carlos A. da; Abrao, Alcidio

    2006-01-01

    The rare earth elements (REE) solubility with ammonium carbonate vary progressively from element to element, the heavy rare earth elements (HRE) being more soluble than the light rare earth elements (LRE). Their solubility is function of the carbonate concentration and the kind of carbonate as sodium, potassium and ammonium. In this work, it is explored this ability of the carbonate for the dissolution of the REE and an easy separation of yttrium was achieved using the precipitation of the peroxide from complex yttrium carbonate. For this work is used a REE concentrate containing (%) Y 2 O 3 2.4, Dy 2 O 3 0.6, Gd 2 O 3 2.7, CeO 2 2.5, Nd 2 O 3 33.2, La 2 O 3 40.3, Sm 2 O 3 4.1 and Pr 6 O 11 7.5. The mentioned concentrate was produced industrially from the chemical treatment of monazite sand by NUCLEMON in Sao Paulo. The yttrium concentrate was treated with 200 g L -1 ammonium carbonate during 10 and 30 min at room temperature. The experiments indicated that a single leaching operation was sufficient to get a rich yttrium solution with about 60.3% Y 2 O 3 . In a second step, this yttrium solution was treated with an excess of hydrogen peroxide (130 volumes), cerium, praseodymium and neodymium peroxides being completely precipitated and separated from yttrium. Yttrium was recovered from the carbonate solution as the oxalate and finally as oxide. The final product is an 81% Y 2 O 3 . This separation envisages an industrial application. The work discussed the solubility of the REE using ammonium carbonate and the subsequent precipitation of the correspondent peroxides

  14. Impacts of yttrium substitution on FMR line-width and magnetic properties of nickel spinel ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Ishaque, M., E-mail: ishaqdgk1@gmail.com [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Khan, Muhammad Azhar, E-mail: azhar.khan@iub.edu.pk [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Ali, Irshad; Khan, Hasan M. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Iqbal, M. Asif [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); College of E & ME, National University of Science and Technology, Islamabad (Pakistan); Islam, M.U. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Warsi, Muhammad Farooq [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan)

    2015-05-15

    The influence of yttrium (Y) substitution on ferromagnetic resonance (FMR), initial permeability, and magnetic properties of NiFe{sub 2}O{sub 4} ferrites were investigated. It was observed that the FMR line-width decreases with yttrium contents for the substitution level 0≤×≤0.06. Beyond this, the FMR line-width increases with yttrium contents. The nominal composition NiY{sub 0.12}Fe{sub 1.88}O{sub 4} exhibited the smallest FMR line-width ~282 Oe. A significant change in FMR position of nickel–yttrium (Ni–Y) ferrites was observed and it found to exist between 4150 and 4600 Oe. The saturation magnetization was observed to decrease with the increase of yttrium contents and this was referred to the redistribution of cations on octahedral. The coercivity increased from 15 Oe to 59 Oe by increasing the yttrium concentration. The initial permeability decreased from 110 to 35 at 1 MHz by the incorporation of yttrium and this was attributed to the smaller grains which may obstruct the domain wall movement and impede the domain wall motion. The magnetic loss factors of substituted samples exhibit decreasing behavior in the frequency range 1 kHz to 10 MHz. The smaller FMR line-width and reduced magnetic loss factor of the investigated samples suggest the possible use of these materials in high frequency applications. - Highlights: • Influence of Y{sup 3+} substitution on the properties of nickel ferrites is investigated. • Very small FMR line-width (282 Oe) is exhibited by these substituted ferrites. • Fourfold increase in coercivity was observed for NiY{sub 0.24}Fe{sub 1.76}O{sub 4} ferrites.

  15. Lanthanide complexes that respond to changes in cyanide concentration in water

    International Nuclear Information System (INIS)

    Routledge, Jack D.; Zhang, Xuejian; Connolly, Michael; Tropiano, Manuel; Blackburn, Octavia A.; Beer, Paul D.; Aldridge, Simon; Faulkner, Stephen; Kenwright, Alan M.

    2017-01-01

    Cyanide ions are shown to interact with lanthanide complexes of phenacylDO3A derivatives in aqueous solution, giving rise to changes in the luminescence and NMR spectra. These changes are the consequence of cyanohydrin formation, which is favored by the coordination of the phenacyl carbonyl group to the lanthanide center. These complexes display minimal affinity for fluoride and can detect cyanide at concentrations less than 1 μm. By contrast, lanthanide complexes with DOTAM derivatives display no affinity for cyanide in water, but respond to changes in fluoride concentration. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Lanthanide complexes that respond to changes in cyanide concentration in water

    Energy Technology Data Exchange (ETDEWEB)

    Routledge, Jack D.; Zhang, Xuejian; Connolly, Michael; Tropiano, Manuel; Blackburn, Octavia A.; Beer, Paul D.; Aldridge, Simon; Faulkner, Stephen [Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford (United Kingdom); Kenwright, Alan M. [Department of Chemistry, Durham University (United Kingdom)

    2017-06-26

    Cyanide ions are shown to interact with lanthanide complexes of phenacylDO3A derivatives in aqueous solution, giving rise to changes in the luminescence and NMR spectra. These changes are the consequence of cyanohydrin formation, which is favored by the coordination of the phenacyl carbonyl group to the lanthanide center. These complexes display minimal affinity for fluoride and can detect cyanide at concentrations less than 1 μm. By contrast, lanthanide complexes with DOTAM derivatives display no affinity for cyanide in water, but respond to changes in fluoride concentration. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. 2,2',-bipyridine and 1,10-phenanthroline complexes of lanthanide(III) trifluoroacetates

    International Nuclear Information System (INIS)

    Misra, S.N.; Singh, M.

    1983-01-01

    The syntheses and characterization of lanthanide(III) triflloroacetate complexes with 2,2'-bipyridine and 1,10-phenanthroline are reported. Lanthanide(III) trifluoroacetates yield compounds of the type Ln(CF 3 COO) 3 .bipy or phen with 2,2'-bipyridine and 1,10-phenanthroline. Their properties and structures have been studied using chemical analyses. electronic and infrared spectra. Thermal analysis of a few complexes have also been done. The infrared data show that the trifluoroacetate group acts as a bidentate ligand making the coordination number of lanthanide eight. (author)

  18. MCrAlY bond coat with enhanced yttrium

    Science.gov (United States)

    Jablonski, Paul D.; Hawk, Jeffrey A.

    2016-08-30

    One or more embodiments relates to a method of producing an MCrAlY bond coat comprising an MCrAlY layer in contact with a Y--Al.sub.2O.sub.3 layer. The MCrAlY layer is comprised of a .gamma.-M solid solution, a .beta.-MAl intermetallic phase, and Y-type intermetallics. The Y--Al.sub.2O.sub.3 layer is comprised of Yttrium atoms coordinated with oxygen atoms comprising the Al.sub.2O.sub.3 lattice. The method comprises depositing an MCrAlY material on a substrate, applying an Y.sub.2O.sub.3 paste, and heating the substrate in a non-oxidizing atmosphere at a temperature between 400-1300.degree. C. for a time sufficient to generate the Y--Al.sub.2O.sub.3 layer. Both the MCrAlY layer and the Y--Al.sub.2O.sub.3 layer have a substantial absence of Y.sub.2O.sub.3, YAG, and YAP phases.

  19. A divalent rare earth oxide semiconductor: Yttrium monoxide

    Science.gov (United States)

    Kaminaga, Kenichi; Sei, Ryosuke; Hayashi, Kouichi; Happo, Naohisa; Tajiri, Hiroo; Oka, Daichi; Fukumura, Tomoteru; Hasegawa, Tetsuya

    Rare earth sesquioxides like Y2O3 are known as widegap insulators with the highly stable closed shell trivalent rare earth ions. On the other hand, rare earth monoxides such as YO have been recognized as gaseous phase, and only EuO and YbO were thermodynamically stable solid-phase rock salt monoxides. In this study, solid-phase rock salt yttrium monoxide, YO, was synthesized in a form of epitaxial thin film by pulsed laser deposition method. YO possesses unusual valence of Y2+ ([Kr] 4d1) . In contrast with Y2O3, YO was narrow gap semiconductor with dark-brown color. The electrical conductivity was tunable from 10-1 to 103 Ω-1 cm-1 by introducing oxygen vacancies as electron donor. Weak antilocalization behavior was observed indicating significant spin-orbit coupling owing to 4 d electron carrier. The absorption spectral shape implies the Mott-Hubbard insulator character of YO. Rare earth monoixdes will be new platform of functional oxides. This work was supported by JST-CREST, the Japan Society for the Promotion of Science (JSPS) with Grant-in-Aid for Scientific Research on Innovative Areas (Nos. 26105002 and 26105006), and Nanotechnology Platform (Project No.12024046) of MEXT, Japan.

  20. Optical properties of ytterbium-doped yttrium oxide ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Solomonov, V.I.; Maksimov, R.N. [Institute of Electrophysics UrB RAS, Amundsena 106, 620016 Ekaterinburg (Russian Federation); Ural Federal University Named After the First President of Russia B.N. Yeltsin, Mira 19, 620002 Ekaterinburg (Russian Federation); Osipov, V.V.; Shitov, V.A.; Lipchak, A.I. [Institute of Electrophysics UrB RAS, Amundsena 106, 620016 Ekaterinburg (Russian Federation)

    2017-05-15

    Ytterbium-doped yttrium oxide (Yb:Y{sub 2}O{sub 3}) transparent ceramics with different sintering additives (Lu{sub 2}O{sub 3}, Sc{sub 2}O{sub 3}, CeO{sub 2}, ZrO{sub 2}, or HfO{sub 2}) were fabricated using nanopowders produced by laser ablation. Transmission and photoluminescence spectra of the obtained ceramics were investigated at room temperature. Highest in-line transmittance was over 80% at the wavelength of 1060 nm for 2 mm thick Yb:Y{sub 2}O{sub 3} ceramics with zirconium and hafnium. Divalent Yb ions with the ground state electron configuration 4f{sup 13}6s were revealed. The absorption and emission bands caused by s <-> s transitions of these ions were observed in the IR spectral range of Yb{sup 3+} ions. The superposition of both Yb{sup 3+} and Yb{sup 2+} emission bands leads to an effective broadening of the whole luminescence band. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Structural and dielectric properties of yttrium-substituted hydroxyapatites

    Energy Technology Data Exchange (ETDEWEB)

    Kaygili, Omer, E-mail: okaygili@firat.edu.tr [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Dorozhkin, Sergey V. [Kudrinskaja sq. 1-155, 123242 Moscow (Russian Federation); Ates, Tankut [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Canan Gursoy, N. [Department of Microbiology and Clinic Microbiology, Inonu University, 44280 Malatya (Turkey); Keser, Serhat [Department of Chemistry, Faculty of Science, Firat University, 23119 Elazig (Turkey); Yakuphanoglu, Fahrettin [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Birkan Selçuk, A. [Technology Department, Saraykoy Nuclear Research and Training Centre, 06983 Ankara (Turkey)

    2015-02-01

    Hydroxyapatite (HAp) samples doped with 0, 2 and 4 at.% of yttrium (Y) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy attached with energy dispersive X-ray (EDX) spectroscopy, antimicrobial activity tests and dielectric studies. The hydroxyl groups observed in FTIR spectra confirmed the formation of HAp phase in the studied samples. The crystallite size, crystallinity degree and lattice parameters of the samples were changed with Y content. The volume of the unit cell was gradually decreased with the addition of Y. Undoped and Y-containing HAp samples were screened to determine their in vitro antimicrobial activities against the standard strains. It was found that no samples have any antimicrobial effect. The relative dielectric permittivity and dielectric loss are affected by Y content. While the alternating current conductivity increases with increasing frequency, it decreases with increasing Y content. - Highlights: • The lattice parameters and crystal size are affected by Y content. • The volume of the unit cell was gradually decreased with the addition of Y. • No samples have any antimicrobial effect. • The alternating current conductivity decreases with increasing Y content.

  2. High density Gd-substituted yttrium iron garnets by coprecipitation

    International Nuclear Information System (INIS)

    Lamastra, Francesca Romana; Bianco, Alessandra; Leonardi, Federica; Montesperelli, Giampiero; Nanni, Francesca; Gusmano, Gualtiero

    2008-01-01

    Gadolinium-substituted yttrium iron garnets are ferrite materials of primary importance in microwave engineering. Stoichiometric powders of nominal composition Y 2.6 Gd 0.4 Fe 5 O 12 (i.e. Fe/(Y + Gd) = 1.67) were prepared by reverse strike coprecipitation of metal nitrates. In order to investigate the influence of composition on phase formation, non-stoichiometric powders were also synthesised. On the basis of DTA/TGA analysis, dried coprecipitates were calcined between 600 deg. C and 1200 deg. C and then characterised by ICP, XRD and HT-XRD. Amorphous coprecipitates crystallise around 700 deg. C in cubic garnet phase along with small amounts of YFeO 3 and/or α-Fe 2 O 3 . Only iron-rich garnets, either pure or Gd-substituted, calcined at 1200 deg. C or above display a single-phase cubic garnet. According to thermal dilatometry results, calcined powders were sintered in air up to 1470 deg. C. The microstructure of sintered ceramics is made up of fine grains, the average size ranging between 3 μm and 13 μm. Density of sintered bodies ranged from 88% to 98%. Ferromagnetic resonance linewidth (ΔH -3dB ) ranged between 4352.9 A m -1 and 4392.7 A m -1 , depending on composition and microstructure

  3. Dielectronic satellites to the Ne-like yttrium resonance lines

    International Nuclear Information System (INIS)

    Osterheld, A.L.; Nilsen, J.; Khakhalin, S.Ya.; Faenov, A.Ya.; Pikuz, S.A.

    1996-01-01

    We present a detailed analysis of the spectrum of satellite transitions to the n=2-3 and n=2-4 Ne-like yttrium resonance lines. Satellite lines from the double excited 2s 2 2p 5 3l3l', 2s 2 2p 5 3l4l', 2s2p 6 3l3l' and 2s2p 6 3l4l' levels of Na-like Y as well as from 2s 2 2p 5 3l3l'3l '' and 2s2p 6 3l3l'3l '' levels of Mg-like Y were observed in spectra from a laser-produced plasma. The X-ray spectra were recorded with high spectral resolution λ/Δλ∼3500-5000 in the wavelength region of the n=2-3 Ne-like resonance lines and with λ/Δλ>1000 in the region of the n=2-4 Ne-like resonance lines. A total of more than 50 spectral features were identified, and their wavelengths were measured. A simple intensity model was developed, which agreed well with the measured spectra and assisted the line identification. The consistency of the model for different spectral regions demonstrates the potential of the Na-like and Mg-like satellite lines for diagnosing plasma conditions. (orig.)

  4. Phase Diagram for Magnon Condensate in Yttrium Iron Garnet Film

    Science.gov (United States)

    Li, Fuxiang; Saslow, Wayne M.; Pokrovsky, Valery L.

    2013-01-01

    Recently, magnons, which are quasiparticles describing the collective motion of spins, were found to undergo Bose-Einstein condensation (BEC) at room temperature in films of Yttrium Iron Garnet (YIG). Unlike other quasiparticle BEC systems, this system has a spectrum with two degenerate minima, which makes it possible for the system to have two condensates in momentum space. Recent Brillouin Light Scattering studies for a microwave-pumped YIG film of thickness d = 5 μm and field H = 1 kOe find a low-contrast interference pattern at the characteristic wavevector Q of the magnon energy minimum. In this report, we show that this modulation pattern can be quantitatively explained as due to unequal but coherent Bose-Einstein condensation of magnons into the two energy minima. Our theory predicts a transition from a high-contrast symmetric state to a low-contrast non-symmetric state on varying the d and H, and a new type of collective oscillation. PMID:23455849

  5. Few-MeV neutrons incident on yttrium

    International Nuclear Information System (INIS)

    Budtz-Jorgensen, C.; Guenther, P.; Smith, A.; Whalen, J.

    1982-09-01

    Neutron total and scattering cross sections of elemental yttrium are measured in the few-MeV region with broad resolutions. The total-cross section measurements extend from approx. = 0.5 to 4.2 MeV in steps of less than or equal to 0.1 MeV. Neutron elastic- and inelastic-scattering cross sections are measured from approx. = 1.5 to 4.0 MeV, at incident-neutron energy intervals of less than or equal to 50 keV and at ten or more scattering angles distributed between 20 and 160 deg. Inelastically-scattered neutron groups are observed corresponding to the excitation of levels at 909 +- 23, 1504 +- 20, 1747 +- 16, 2224 +- 16, 2567 +- 26, 2889 +- 12 and 3104 +- 10 keV. The experimental results are discussed in terms of the spherical optical-statistical, coupled-channels and core-coupling models and compared with corresponding quantities given in the evaluated nuclear data file ENDF/B-V

  6. Deposition of yttrium oxysulfide thin films by atomic layer epitaxy

    International Nuclear Information System (INIS)

    Kukli, K.; University of Tartu, Tartu,; Johansson, L-S.; Nykaenen, E.; Peussa, M.; Ninistoe, L.

    1998-01-01

    Full text: Yttrium oxysulfide is a highly interesting material for optoelectronic applications. It is industrially exploited in the form of doped powder in catholuminescent phosphors, e.g. Y 2 O 2 S: Eu 3+ for colour TV. Attempts to grow thin films of Y 2 O 2 S have not been frequent and only partially successful due to the difficulties in obtaining crystalline films at a reasonable temperature. Furthermore, sputtering easily leads to a sulphur deficiency. Evaporation of the elements from a multi-source offers a better control of the stoichiometry resulting in hexagonal (0002) oriented films at 580 deg C. In this paper we present the first successful thin film growth experiments using a chemical process with molecular precursors. Atomic layer epitaxy (ALE) allows the use of a relatively low deposition temperature and thus compatibility with other technologies. Already at 425 deg C the reaction between H 2 S and Y(thd) 3 (thd = 2,2,6,6 - tetramethyl-heptane-3,5- dione) yields a crystalline Y 2 O 2 S thin film which was characterized by XRD, XRF and XPS

  7. Yttrium 90 microspheres for the treatment of hepatocellular carcinoma.

    Science.gov (United States)

    Memon, Khairuddin; Lewandowski, Robert J; Riaz, Ahsun; Salem, Riad

    2013-01-01

    Yttrium-90 microspheres are radioactive particles which are increasingly being employed for treating patients with unresectable hepatocellular carcinoma (HCC). The procedure is called radioembolization. It involves the injection of micron-sized embolic particles loaded with a radioisotope by use of transarterial techniques. Because of the sensitivity of liver parenchyma and relative insensitivity of tumor, external radiation has played a limited role in treating HCC. (90)Y administered via arterial route directs the highly concentrated radiation to the tumor while healthy liver parenchyma is relatively spared due to its preferential blood supply from portal venous blood. This technique has proven useful for the majority of patients with HCC as most of them present in advanced stage, beyond potentially curative options (resection/liver transplantation). (90)Y microspheres can be used in downstaging large tumors to bring within transplantable criteria, in patients with portal venous thrombosis due to tumor invasion and as palliative therapy. There are two available devices for (90)Y administration; TheraSphere® (glass based) and SIR-Spheres® (resin based). The procedure is performed on an outpatient basis. The incidence of complications is comparatively less and may include nausea, fatigue, abdominal pain, hepatic dysfunction, biliary injury, fibrosis, radiation pneumonitis, GI ulcers, and vascular injury; however, these can be avoided by meticulous pretreatment assessment, careful patient selection, and adequate dosimetry. This article explores the technical and clinical aspects of (90)Y radioembolization with keeping emphasis on patient selection, uses, and complications.

  8. Structural and dielectric properties of yttrium-substituted hydroxyapatites

    International Nuclear Information System (INIS)

    Kaygili, Omer; Dorozhkin, Sergey V.; Ates, Tankut; Canan Gursoy, N.; Keser, Serhat; Yakuphanoglu, Fahrettin; Birkan Selçuk, A.

    2015-01-01

    Hydroxyapatite (HAp) samples doped with 0, 2 and 4 at.% of yttrium (Y) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy attached with energy dispersive X-ray (EDX) spectroscopy, antimicrobial activity tests and dielectric studies. The hydroxyl groups observed in FTIR spectra confirmed the formation of HAp phase in the studied samples. The crystallite size, crystallinity degree and lattice parameters of the samples were changed with Y content. The volume of the unit cell was gradually decreased with the addition of Y. Undoped and Y-containing HAp samples were screened to determine their in vitro antimicrobial activities against the standard strains. It was found that no samples have any antimicrobial effect. The relative dielectric permittivity and dielectric loss are affected by Y content. While the alternating current conductivity increases with increasing frequency, it decreases with increasing Y content. - Highlights: • The lattice parameters and crystal size are affected by Y content. • The volume of the unit cell was gradually decreased with the addition of Y. • No samples have any antimicrobial effect. • The alternating current conductivity decreases with increasing Y content

  9. Hydrothermal synthesis and formation mechanism of hexagonal yttrium hydroxide fluoride nanobundles

    International Nuclear Information System (INIS)

    Tian, Li; Sun, QiLiang; Zhao, RuiNi; He, HuiLin; Xue, JianRong; Lin, Jun

    2013-01-01

    Graphical abstract: The formation of yttrium hydroxide fluorides nanobundles can be expressed as a precipitation transformation from cubic NaYF 4 to hexagonal NaYF 4 and to hexagonal Y(OH) 2.02 F 0.98 owing to ion exchange. - Highlights: • Novel Y(OH) 2.02 F 0.98 nanobundles have been successfully prepared by hydrothermal method. • The branched nanobundles composed of numerous oriented-attached nanoparticles has been studied. • The growth mechanism is proposed to be ion exchange and precipitation transformation. - Abstract: This article presents the fabrication of hexagonal yttrium hydroxide fluoride nanobundles via one-pot hydrothermal process, using yttrium nitrate, sodium hydroxide and ammonia fluoride as raw materials to react in propanetriol solvent. The X-ray diffraction pattern clearly reveals that the grown product is pure yttrium hydroxide fluoride, namely Y(OH) 2.02 F 0.98 . The morphology and microstructure of the synthesized product is testified to be nanobundles composed of numerous oriented-attached nanoparticles as observed from the field emission scanning electron microscopy (FESEM). The chemical composition was analyzed by the energy dispersive spectrum (EDS), confirming the phase transformation of the products which was clearly consistent with the result of XRD analysis. It is proposed that the growth of yttrium hydroxide fluoride nanobundles be attributed to ion exchange and precipitation transformation

  10. Development of 2024 AA-Yttrium composites by Spark Plasma Sintering

    Science.gov (United States)

    Vidyasagar, CH S.; Karunakar, D. B.

    2018-04-01

    The method of fabrication of MMNCs is quite a challenge, which includes advanced processing techniques like Spark Plasma Sintering (SPS), etc. The objective of the present work is to fabricate aluminium based MMNCs with the addition of small amounts of yttrium using Spark Plasma Sintering and to evaluate their mechanical and microstructure properties. Samples of 2024 AA with yttrium ranging from 0.1% to 0.5 wt% are fabricated by Spark Plasma Sintering (SPS). Hardness of the samples is determined using Vickers hardness testing machine. The metallurgical characterization of the samples is evaluated by Optical Microscopy (OM), Field Emission Scanning Electron Microscopy (FE-SEM). Unreinforced 2024 AA sample is also fabricated as a benchmark to compare its properties with those of the composite developed. It is found that the yttrium addition increases the above mentioned properties by altering the precipitation kinetics and intermetallic formation to some extent and then decreases gradually when yttrium wt% increases beyond 0.3 wt%. High density (˂ 99.75) is achieved in the samples and highest hardness achieved is 114 Hv, fabricated by spark plasma sintering and uniform distribution of yttrium is observed.

  11. Flexible Photonics: Polymer LEDs Made from Monochromatic Red Emitting Lanthanide/Polymer Blends. Phase 1

    National Research Council Canada - National Science Library

    O'Regan, Marie

    1999-01-01

    .... Spectrally pure, red emitting flexible LEDs have been fabricated. Close to a four-fold increase in device efficiency is obtained when a suitable lanthanide complex is blended with the semi-conducting host polymer...

  12. Detection of Fluorescence for Lanthanides in LiCl-KCl Molten Salt Medium

    International Nuclear Information System (INIS)

    Im, Hee Jung; Kim, Tack Jin; Song, Kyu Seok; Jee, Kwang Yong

    2007-01-01

    In the electrorefining step of the pyrochemical process, actinide ions dissolved in the LiCl-KCl eutectic salt are recovered as pure actinide metals at a cathode for a re-use as a nuclear fuel from the aspect of its nonproliferation of the nuclear fuel cycles. The lanthanide species dissolved in the LiCl-KCl eutectic salt play an important role in an effective metal purification during the electrorefining step, so it is necessary to understand the chemical and physical behaviors of lanthanides in molten salt. The in situ spectroscopic measurement system and studies according to temperature changes are essential for better understandable information. To our knowledge, the absorption studies of lanthanides at high temperatures have been reported before, but the fluorescence studies of those at high temperature are not reported yet. We will discuss here the fluorescence behaviors of lanthanides in LiCl-KCl molten salt medium according to a changing temperature

  13. Separation of interfering elements in the neutron activation analysis of lanthanides in geological materials

    International Nuclear Information System (INIS)

    Saiki, M.

    1988-01-01

    A chemical procedure has been developed for the separation of U, Th, Fe, Sc, Na,Ta, and Mo which interfere in the neutron activation analysis of the lanthanide elements in geological materials. This procedure is based on the solvent extraction of interferents using a solution of tetracycline in benzyl alcohol. The lanthanide elements remaining in the aqueous phase are coprecipitated on calcium oxalate or ferric hydroxide for irradiation and subsequent determination by gamma ray spectrometry. The chemical separation procedure was applied in the analysis of lanthanides in two international geological reference materials GSP-1 (USGS), GS-N (CRPG) and in the analysis of a volcanic rock from Pocos de Caldas, MG, Brazil. The sensitivities for all the lanthanides were determined. (author) [pt

  14. Multicolour synthesis in lanthanide-doped nanocrystals through cation exchange in water

    KAUST Repository

    Han, Sanyang; Qin, Xian; An, Zhongfu; Zhu, Yihan; Liang, Liangliang; Han, Yu; Huang, Wei; Liu, Xiaogang

    2016-01-01

    lanthanide-doped luminescent nanomaterials have relied on direct synthesis requiring stringent controls over crystal nucleation and growth at elevated temperatures. Here we demonstrate the use of a cation exchange strategy for expeditiously accessing large

  15. FY17 Progress in Modeling of Lanthanide Transport in Metallic Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Unal, Cetin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Matthews, Christopher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-19

    A critical review of fuel-clad-chemical interactions along with modelling requirements is published. The mechanism of lanthanide transport is studied experimentally (NEUP collaboration) and using simulations and initial results are published in Refs.

  16. Spectrophotometric, potentiometric, and gravimetric determination of lanthanides with peri-dihydroxynaphthindenone

    International Nuclear Information System (INIS)

    Hassan, S.S.M.; Mahmoud, W.H.

    1982-01-01

    Sensitive and reasonably selective methods are described for the spectrophotometric, potentiometric, and gravimetric determination of lanthanides using peri-dihydroxynaphthindenone as a novel chromogenic and precipitating reagent. The reagent forms a stable 1:2 (metal:reagent) type of complex with light lanthanides at pH 2-7 in 1:1 ethanol-water mixture. Low metal concentrations ( 4 L mol -1 cm -1 ) which obey Beer's law. Quantitative precipitation of the complexes from metal solutions of concentrations > 100 μg/mL permits both gravimetric quantitation by igniting the precipitates to the metal oxides and potentiometric titration of the excess reagent. Results with an average recovery of 98% (standard deviation 0.7%) are obtainable for 0.1 μg to 200 mg of all light lanthanides. Many foreign ions naturally occurring or frequently associated with lanthanides do not interfere or can be tolerated

  17. Handbook on the physics and chemistry of rare earths: Volume 19: Lanthanides/Actinides: Physics, 2

    International Nuclear Information System (INIS)

    Gschneidner, Karl A.; Eyring, LeRoy; Choppin, G.R.; Lander, G.H.

    1994-01-01

    This handbook comprises five chapters on the lanthanide and actinide materials. In the first chapter the inelastic neutron scattering behaviors of the lanthanides and actinides are compared. In the next chapter the focus is on neutron scattering by heavy fermion single crystal materials, including metallic materials with a paramagnetic ground state, superconductors, metallic and semiconducting antiferromagnets and nearly insulating paramagnets. In chapter three a comprehensive review of intermediate valence and heavy fermions in a wide variety of lanthanide and actinide compounds is given, ranging from metallic to insulating materials. In chapter four two issues on the high pressure behaviours of anomalous cerium, ytterbium and uranium compounds are dealt with. In the final chapter an extensive review is given the thermodynamic properties of lanthanide and actinide metallic systems

  18. Lanthanide Selective Sorbents: Self-Assembled Monolayers on Mesoporous Supports (SAMMS)

    Energy Technology Data Exchange (ETDEWEB)

    Fryxell, Glen E.; Wu, Hong; Lin, Yuehe; Shaw, Wendy J.; Birnbaum, Jerome C.; Linehan, John C.; Nie, Zimin; Kemner, K. M.; Kelly, Shelley

    2004-11-01

    Through the marriage of mesoporous ceramics with self-assembled monolayer chemistry, the genesis of a powerful new class of environmental sorbent materials has been realized. By coating the mesoporous ceramic backbone with a monolayer terminated with a lanthanide-specific ligand, it is possible to couple high lanthanide binding affinity with the high loading capacity (resulting from the extremely high surface area of the support). This lanthanide-specific ligand field is created by pairing a ''hard'' anionic Lewis base with a suitable synergistic ligand, in a favorable chelating geometry. Details of the synthesis, characterization, lanthanide binding studies, binding kinetics, competition experiments and sorbent regeneration studies are summarized

  19. Thermal, spectroscopic and laser properties of Nd3+ in gadolinium scandium gallium garnet crystal produced by optical floating zone method

    Science.gov (United States)

    Tian, Li; Wang, Shuxian; Wu, Kui; Wang, Baolin; Yu, Haohai; Zhang, Huaijin; Cai, Huaqiang; Huang, Hui

    2013-12-01

    A neodymium-doped gadolinium scandium gallium garnet (Nd:GSGG) single crystal with dimensions of Φ 5 × 20 mm2 has been grown by means of optical floating zone (OFZ). X-ray powder diffraction (XRPD) result shows that the as-grown Nd:GSGG crystal possesses a cubic structure with space group Ia3d and a cell parameter of a = 1.2561 nm. Effective elemental segregation coefficients of the Nd:GSGG as-grown crystal were calculated by using X-ray fluorescence (XRF). The thermal properties of the Nd:GSGG crystal were systematically studied by measuring the specific heat, thermal expansion and thermal diffusion coefficient, and the thermal conductivity of this crystal was calculated. The absorption and luminescence spectra of Nd:GSGG were measured at room temperature (RT). By using the Judd-Ofelt (J-O) theory, the theoretical radiative lifetime was calculated and compared with the experimental result. Continuous wave (CW) laser performance was achieved with the Nd:GSGG at the wavelength of 1062 nm when it was pumped by a laser diode (LD). A maximum output power of 0.792 W at 1062 nm was obtained with a slope efficiency of 11.89% under a pump power of 7.36 W, and an optical-optical conversion efficiency of 11.72%.

  20. Determination of stability constants of lanthanide nitrate complex formation using a solvent extraction technique

    International Nuclear Information System (INIS)

    Andersson, S.; Ekberg, C.; Liljenzin, J.O.; Nilsson, M.; Skarnemark, G.; Eberhardt, K.

    2006-01-01

    For lanthanides and actinides, nitrate complex formation is an important factor with respect to the reprocessing of nuclear fuels and in studies that treat partitioning and transmutation/conditioning. Different techniques, including microcalorimetry, various kinds of spectroscopy, ion-exchange and solvent extraction, can be used to determine stability constants of nitrate complex formation. However, it is uncommon that all lanthanides are studied at the same time, using the same experimental conditions and technique. The strengths of the complexes are different for lanthanides and actinides, a feature that may assist in the separation of the two groups. This paper deals with nitrate complex formation of lanthanides using a solvent extraction technique. Trace amounts of radioactive isotopes of lanthanides were produced at the TRIGA Mainz research reactor and at the Institutt for Energiteknikk in Kjeller, Norway (JEEP II reactor). The extraction of lanthanide ions into an organic phase consisting of 2, 6-bis-(benzoxazolyl)-4-dodecyloxylpyridine, 2-bromodecanoic acid and tert-butyl benzene as a function of nitrate ion concentration in the aqueous phase was studied in order to estimate the stability constants of nitrate complex formation. When the nitrate ion concentration is increased in the aqueous phase, the nitrate complex formation starts to compete with the extraction of metal ions. Thus the stability constants of nitrate complex formation can be estimated by measuring the decrease in extraction and successive fitting of an appropriate model. Extraction curves for La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Dy, Ho and Er were obtained and stability constants for their nitrate complex formation were estimated. Tb, Tm, Yb and Lu were also investigated, but no stability constants could be determined. The distribution ratios for the metal ions at low nitrate ion concentration were obtained at the same time, showing the effect of lanthanide contraction resulting in decreasing

  1. Citrate-based open-quotes Talspeakclose quotes actinide-lanthanide separation process

    International Nuclear Information System (INIS)

    Del Cul, G.D.; Toth, L.M.; Bond, W.D.

    1997-01-01

    Lanthanide elements are produced in relatively high yield by fission of 235 U. Almost all the lanthanide isotopes decay to stable nonradioactive lanthanide isotopes in a relatively short time. Consequently, it is highly advantageous to separate the relatively small actinide fraction from the relatively large quantities of lanthanide isotopes. The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Complexes) is one of the few means available to separate the trivalent actinides from the lanthanides. Previous work based on the use of lactic or glycolic acid has shown deleterious effects of some impurity ions such as zirconium(IV), even at concentrations on the order of 10 -4 M. Other perceived problems were the need to maintain the pH and reagent concentrations within a narrow range and a significant solubility of the organic phase at high carboxylic acid concentrations. The authors' cold experiments showed that replacing the traditional extractants glycolic or lactic acid with citric acid eliminates or greatly reduces the deleterious effects produced by impurities such as zirconium. An extensive series of batch tests was done using a wide range of reagent concentrations at different pH values, temperatures, and contact times. The results demonstrated that the citrate-based TALSPEAK can tolerate appreciable changes in pH and reagent concentrations while maintaining an adequate lanthanide extraction. Experiments using a three-stage glass mixer-settler showed a good lanthanide extraction, appropriate phase disengagement, no appreciable deleterious effects due to the presence of impurities such as zirconium, excellent pH buffering, and no significant loss of organic phase

  2. SEPARATION OF EUROPIUM FROM OTHER LANTHANIDE RAE EARTHS BY SOLVENT EXTRACTION

    Science.gov (United States)

    Peppard, D.F.; Horwitz, E.P.; Mason, G.W.

    1963-02-12

    This patent deals with a process of separating europium from other lanthanides present in aqueous hydrochloric or sulfuric acid solutions. The europium is selectively reduced to the divalent state with a divalent chromium salt formed in situ from chromium(III) salt plus zinc amalgam. The other trivalent lanthanides are then extracted away from the divalent europium with a nitrogen-flushed phosphoric acid ester or a phosphonic acid ester. (AEC)

  3. The kinetics of lanthanide complexation by EDTA and DTPA in lactate media.

    Science.gov (United States)

    Nash, K L; Brigham, D; Shehee, T C; Martin, A

    2012-12-28

    The interaction of trivalent lanthanide and actinide cations with polyaminopolycarboxylic acid complexing agents in lactic acid buffer systems is an important feature of the chemistry of the TALSPEAK process for the separation of trivalent actinides from lanthanides. To improve understanding of metal ion coordination chemistry in this process, the results of an investigation of the kinetics of lanthanide complexation by ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA) and diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) in 0.3 M lactic acid/0.3 M ionic strength solution are reported. Progress of the reaction was monitored using the distinctive visible spectral changes attendant to lanthanide complexation by the colorimetric indicator ligand Arsenazo III, which enables the experiment but plays no mechanistic role. Under the conditions of these experiments, the reactions occur in a time regime suitable for study by stopped-flow spectrophotometric techniques. Experiments have been conducted as a function of EDTA/DTPA ligand concentration, total lactic acid concentration, and pH. The equilibrium perturbation reaction proceeds as a first order approach to equilibrium over a wide range of conditions, allowing the simultaneous determination of complex formation and dissociation rate constants. The rate of the complexation reaction has been determined for the entire lanthanide series (except Pm(3+)). The predominant pathway for lanthanide-EDTA and lanthanide-DTPA dissociation is inversely dependent on the total lactate concentration; the complex formation reaction demonstrates a direct dependence on [H(+)]. Unexpectedly, the rate of the complex formation reaction is seen in both ligand systems to be fastest for Gd(3+). Correlation of these results indicates that in 0.3 M lactate solutions the exchange of lanthanide ions between lactate complexes and the polyaminopolycarboxylate govern the process.

  4. Studies on trivalent lanthanide complexes of bis-vanillin p-phenylenediamine

    International Nuclear Information System (INIS)

    Shahma, Abu; Ahmad, Naseer

    1983-01-01

    The coordination interaction of lanthanide(III) chlorides with bis-vanillin o-phenylenediamine was studied by Ansari and Ahmad (1977). It was thought fruitful to compare these with the complexes of trivalent lanthanide ions with bis-vanillin p-phenylenediamine. The newly synthesized complexes were subjected to elemental, thermogravimetric and differential thermal analyses and their melting points, magnetic susceptibilities, molar conductances determined and infrared and electronic spectra taken. (author)

  5. Lanthanide alkyl and silyl compounds: Synthesis, reactivity and catalysts for green

    Energy Technology Data Exchange (ETDEWEB)

    Pindwal, Aradhana [Iowa State Univ., Ames, IA (United States)

    2016-01-01

    The last few decades have witnessed enormous research in the field of organometallic lanthanide chemistry. Our research group has developed a few rare earth alkyl compounds containing tris(dimethylsilyl)methyl ligand and explored their reactivity. This thesis focusses on extending the study of lanthanide alkyl and silyl compounds to develop strategies for their synthesis and explore their reactivity and role as catalysts in processes such as hydrosilylation and cross-dehydrocoupling.

  6. Application of lanthanide ions doped in different glasses

    International Nuclear Information System (INIS)

    Dhondiyal, Charu Chandra

    2015-01-01

    The transfer of optical excitation energy from one ion/molecule to another ion/molecule has proved to be of potential importance in industrial application as well as research. Rare earth elements (RE) although not as rare as some of them occur more prevalently then other well known material (e.g. silver, tin, tungsten) are special group of elements of the periodic table comprising lanthanide series (from lanthanum to lutetium) and actinide series (from actinium to lawrencium). Most of the actinides are highly radioactive hence their uses are limited. Fluorescence is the particular optical property of lanthanide (RE) ions. The narrow absorption and emission lines exhibited by the RE ions in crystals, glasses and solutions have always made these ions attractive as sensitive probes of solids and liquid state and also makes them useful in laser technology, CRT displays, UV to visible converters and optical communications etc. In recent years there has been a special interest to study the properties and applications of rare earth doped in glasses. Lanthanide ions in glasses play an important role, especially by retaining their emission capabilities, in the host matrix. Glass as a dielectric material plays an important role in science and industry. Its chemical, physical and particular optical properties make it suitable for applications such as opto-electronic materials, laboratory equipment, laser gain media, etc. Photoluminescence from rare earth doped glasses are of major interest in the research area of optoelectronic device applications like phosphors, display monitors, lasers and amplifiers for communication systems. Now a days, development of optical devices based on rare-earth ions doped materials is one of the interesting fields of research. Rare earth doped glasses are widely used as laser materials, optical amplifiers, optical memory devices, magneto-optical devices, medical lasers, eye safe lasers, flat panel displays, fluorescent lamps, white LED's etc

  7. Lanthanides in molecular magnetism: old tools in a new field.

    Science.gov (United States)

    Sorace, Lorenzo; Benelli, Cristiano; Gatteschi, Dante

    2011-06-01

    In this tutorial review we discuss some basic aspects concerning the magnetic properties of rare-earth ions, which are currently the subject of a renovated interest in the field of molecular magnetism, after the discovery that slow relaxation of the magnetization at liquid nitrogen temperature can occur in mononuclear complexes of these ions. Focusing on Dy(III) derivatives a tutorial discussion is given of the relation of the crystal field parameters, which determine the anisotropy of these systems and consequently their interesting magnetic properties, with the geometry of the coordination sphere around the lanthanide centre and with the pattern of f orbitals. The problem of systems of low point symmetry is also addressed by showing how detailed single crystal investigation, coupled to more sophisticated calculation procedures, is an absolute necessity to obtain meaningful structure-property relationships in these systems.

  8. NMR studies of structures of lanthanide dicarboxylate complexes in solution

    International Nuclear Information System (INIS)

    Choppin, G.R.; Kullberg, L.

    PMR pand 13 C shift data were measured for complexes of Pr(III), Eu(III) and Yb(III) with ethylene 1,2-dioxydiacetate (EDODA), ethylene 1,2-dithiodiacetate (EDSDA), and ethylene, 1,2-diaminodiacetate (EDDA). Solubility problems limited analysis of the EDSDA and EDDA data to qualitative evaluation. In the EDSDA complexes, the data indicate that the sulfur atoms do not participate in bonding to the lanthanide cations. Moreover, both carboxylate groups seem to bind Pr and Eu while Yb interacts with only a single carboxylate group. The EDDA complexes are tetradentate with long lived (NMR scale) Ln-N bonds. Shift theory allowed more quantitative analysis of the EDODA complexes. They are tetradentate with a puckered chelate ring and Ln-O(ether) distances of 2.3 A

  9. Lanthanide and actinide ion phytoextraction: investigations of biosorption chemistry

    International Nuclear Information System (INIS)

    Rayson, Gary D.; Serna, Debbie D.; Moore, Jessica L.

    2009-01-01

    Investigations of the chemical interactions responsible for passive biosorption of a lanthanide (Eu (III)) and an actinide (U (VI)) metal ion is described. Spectroscopic methods for the elucidation of chemical functionalities on cultured anther cell walls from the plant Datura innoxia include metal ion luminescence measurements. These have revealed the presence of distinctly different binding environments involving one, two, and three carboxylate moieties for Eu (III) and UO 2 2+ binding and sulfonates (or sulfates) and phosphates for sequestration of Eu (III) on the uranyl ion, respectively. Additional investigations of the apparent affinities of these metals to this material have revealed the presence of both low and high affinity sites for the binding of Eu (III) with weak electrostatic attractions proposed for binding at high metal concentrations (i.e., low affinities) and surface coordination interactions responsible for higher affinities. Conversely, total uranyl ion binding revealed only a single distribution of interactions based on apparent affinities. (author)

  10. Luminescence properties of isomeric and tautomeric lanthanide pyridinedicarboxylates

    International Nuclear Information System (INIS)

    Puntus, L.N.; Zolin, V.F.; Babushkina, T.A.; Kutuza, I.B.

    2004-01-01

    The luminescence and PMR spectra of europium salts of six isomers of 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, and 3,5-pyridinedicarboxylic acids (PDA) had been studied. The distribution of the effective charge in the nearest surroundings of the Eu 3+ ion in these salts was evaluated from Stark splittings of electronic transitions. The values of relative integral intensities of electronic transitions 5 D 0 - 7 F J (J=0-4) in the luminescence spectra were reported. Compounds investigated were divided into three subgroups taking into account the details of the structure of the ligands and details of the luminescence spectra. The ligand coordination manners as well as the strength of interaction between lanthanide ion and ligands were confirmed by data of the PMR and IR spectroscopy

  11. Organic derivatives of lanthanides containing metal in cycle

    International Nuclear Information System (INIS)

    Syutkina, O.P.; Rybakova, L.F.; Egorova, E.N.; Sigalov, A.B.; Beletskaya, I.P.

    1983-01-01

    The reaction of 2.2'-dilithium biphenyl with LnBr 3 (Ln=Pr, Sm, Gd, Ho, Yb here bromium atoms are comparatively easily replaced. Previously unknown organic derivatives of lanthanides containing metal in the cycle are obtained. It is established that a successful extraction of the compound requires reaction conditions, such as the use of ether as a solvent with the followinq addition of TGP, the order of addition of reagents. Compounds are extracted in the form of solvates containing TGP melecules. The complexes prepared are coloured, depending on the metal, beige (Pr, Sm) brown (Gd, Yb) and red-brown (Ho). They dissolve readily in TGP moderately in benzen toluene, CCl 4 . When stored their solubility in benzene and CCl 4 decreases considerably, and after 3-2 days, they are practically insoluhle. The compounds prepared are characterized by the elementary analysis, IR and PMR spectra

  12. Chelation studies involving decontamination of light lanthanides by polyaminopolycarboxylic

    International Nuclear Information System (INIS)

    Hassan, N.E.H.

    1985-01-01

    The present thesis constitutes chelation studies involving decontamination of light lanthanides, cobalt , and uranium with 2,2-bis-acryloyliminomethylene- acid (BAETA) using the spectrophotometric method. the work carried out aimed to clear up the effectiveness of BAETA as a decontaminating agent for radioactive nuclides from human body . the thesis includes a general introduction , outlines the aim of work and contains three main chapters . the results of the work are discussed at the end of the thesis. the first chapter deals with a comprehensive survey of the relevant literature. this includes the metabolism and toxicity of cerium, uranium, cobalt and Ln +3 elements, general methodologies of internal decontamination, choice and effectiveness of chelating agents

  13. Migration study of actinides and lanthanides in compacted bentonite

    International Nuclear Information System (INIS)

    Sastrowardoyo, P.B.; Susilowati, D.; Suganda, D.

    1998-01-01

    Migration study of actinide and lanthanide elements in compacted bentonite has been conducted. Data of these elements mobilities have been shown, and it is showed that the diffusion coefficient was varied as the function of solution phase condition as well as the origin/composition of bentonite. It is showed that the diffusion coefficient decreased by the increasing of density, as well as the increasing of montmorillonite content in bentonite. The ratio of bentonite/silica-sand used was related to the increasing of elements mobility. In many case the difference of diffusion coefficient was related to the variation of pH and redox condition, as well as the presence of complexant in solution phase. The Lower diffusion coefficient could give the higher retardation factor, which is a favourable factor to retard the radionuclides release from a disposal facility to geosphere. (author)

  14. Separation of Yttrium from Rare Earth Concentrates in Fractional Hydroxide Precipitation

    International Nuclear Information System (INIS)

    Tri Handini; Purwoto; Mulyono

    2007-01-01

    Yttrium has been separated from rare earth concentrates by precipitation in fractional hydroxide using urea. The purpose of this research is to increase the yttrium rate resulting from the sedimentary process through separation of yttrium from other rare earth in fractional hydroxide precipitation using urea. In this research, we study the process variable of the concentration of urea, the ratio of feed volume to condensation volume of urea, as well as the temperature. Determination analysis of the rare earth rate is conducted using an X-ray spectrometer. The best result Y=92.89 % is obtained at a concentration of urea of 50 %, a level of precipitation of 3 times, and a temperature of 80°C. (author)

  15. Fabrication of dense yttrium oxyfluoride ceramics by hot pressing and their mechanical, thermal, and electrical properties

    Science.gov (United States)

    Tahara, Ryuki; Tsunoura, Toru; Yoshida, Katsumi; Yano, Toyohiko; Kishi, Yukio

    2018-06-01

    Excellent corrosion-resistant materials have been strongly required to reduce particle contamination during the plasma process in semiconductor production. Yttrium oxyfluoride can be a candidate as highly corrosion-resistant material. In this study, three types of dense yttrium oxyfluoride ceramics with different oxygen contents, namely, YOF, Y5O4F7 and Y5O4F7 + YF3, were fabricated by hot pressing, and their mechanical, thermal, and electrical properties were evaluated. Y5O4F7 ceramics showed an excellent thermal stability up to 800 °C, a low loss factor, and volume resistivity comparable to conventional plasma-resistant oxides, such as Y2O3. From these results, yttrium oxyfluoride ceramics are strongly suggested to be used as electrostatic chucks in semiconductor production.

  16. Tribological effects of yttrium and nitrogen ion implantation on a precipitation hardening stainless steel

    International Nuclear Information System (INIS)

    Alonso, F.; Arizaga, A.; Garcia, A.; Onate, J.I.

    1994-01-01

    Yttrium, nitrogen and combined yttrium and nitrogen implantations have been carried out on an ASTM A286 precipitation hardening iron base alloy to evaluate the benefits in their tribological behaviour. Microindentation tests have shown a significant 20%-60% increment in hardness on the nitrogen implanted material, with a limited improvement in elastic recovery of the indentation. An abrasive test on the same material has also produced a 50% reduction in scratch depth. Y + and Y + +N + implantations also hardened the material but to a lesser extent. Reciprocating ball on disk friction and wear testing at 400 C resulted in very severe damage in all cases. X-ray photoelectron spectroscopy analyses combined with Ar sputtering have disclosed that nitrogen is mainly in a nitrided form, yttrium remains oxidized at the surface, below which there is an apparent increase in the metallic bond. ((orig.))

  17. Physicochemical analysis of cryocrystallization processes of aqueous solutions of yttrium, barium, copper nitrates and their mixtures

    International Nuclear Information System (INIS)

    Kulakov, A.B.; Mozhaev, A.P.; Tesker, A.M.; Churagulov, B.R.

    1992-01-01

    Products of fast hardening of aqueous solutions of different concentration of yttrium, barium copper nitrates and their mixtures including mixture of three nitrates with molar ratio equal to 1:2:3 used for synthesis of YBa 2 Cu 3 O 7-x HTSC by cryochemical technique, in liquid nitrogen, are studied using low-temperature, differential thermal and X-ray phase analyses. Aqueous solutions of barium, copper, yttrium nitrates are shown to belong to three different classes which differ in behaviour at fast cooling and subsequent slow heating. Cryogranulate at YBa 2 Cu 2 O 7-x synthesis using cryochemical technique represents mixture of X-ray amorphous Ba(NO 3 ) 2 , crystalline Cu(NO 3 ) 2 ·6H 2 O and ice, as well as, supercooled aqueous solution of yttrium and copper nitrates

  18. Fluorimetric determination of yttrium by methyl-bis(8-hydraxy--- 2-quinolyl)amine

    International Nuclear Information System (INIS)

    Golovina, A.P.; Kachin, S.V.; Runov, V.K.; Fakeeva, O.A.

    1982-01-01

    Using a method of mathematical Box-Wilson experiment planning the optimum conditions of yttrium fluorimetric determination by methyl-bis (8-hydroxy-2-quinolyl) amine (pH 7.5, csub(R)=1.4x10sup(-5) M) with the determination limit=0.05 μg/ml are found. An extraction-fluorimetric method of yttrium determination by methyl-bis (8-hydroxy-2-quinolyl) amine is developed. The extraction has been realized with aliphatic alcohols at pH > 11. The method is characteristic of the lowest determination limit (0.01 μg/ml) as compared with the known ones. The possibility is shown of yttrium determination in the presence of 5000-multiple aluminium contents, stoichiometric contents of La, Lu, Fe (3), U (6), tartrates, citrates

  19. Positive effect of yttrium on the reduction of pores in cast Al alloy

    International Nuclear Information System (INIS)

    Hua, Guomin; Ahmadi, Hojat; Nouri, Meisam; Li, Dongyang

    2015-01-01

    Mechanical and electrochemical properties of Al alloys can be improved by adding a small amount of rare-earth such as yttrium. Here we demonstrate that adding yttrium also helps suppress the porosity in cast Al alloys, thus minimizing its detrimental effect on mechanical properties of the alloys. The mechanism behind is elucidated based on the hydrogen binding energies and the diffusion activation energies of hydrogen atoms in Al and Al–Y phases, calculated using the first-principle method. - Highlights: • The porosity of commercial Al alloy can be reduced by additive yttrium. • Formed Al 3 Y phase helps reduce homogeneous nucleation of hydrogen bubbles. • Formed Al 3 Y and Al 2 Y phases could suppress the growth of hydrogen bubbles

  20. Lanthanide-based laser-induced phosphorescence for spray diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Voort, D. D. van der, E-mail: d.d.v.d.voort@tue.nl; Water, W. van de; Kunnen, R. P. J.; Clercx, H. J. H.; Heijst, G. J. F. van [Applied Physics Department, Eindhoven University of Technology, 5612 AZ Eindhoven (Netherlands); Maes, N. C. J.; Sweep, A. M.; Dam, N. J. [Mechanical Engineering Department, Eindhoven University of Technology, 5612 AZ Eindhoven (Netherlands); Lamberts, T. [Institute of Theoretical Chemistry, University of Stuttgart, D-70569 Stuttgart (Germany)

    2016-03-15

    Laser-induced phosphorescence (LIP) is a relatively recent and versatile development for studying flow dynamics. This work investigates certain lanthanide-based molecular complexes for their use in LIP for high-speed sprays. Lanthanide complexes in solutions have been shown to possess long phosphorescence lifetimes (∼1-2 ms) and to emit light in the visible wavelength range. In particular, europium and terbium complexes are investigated using fluorescence/phosphorescence spectrometry, showing that europium-thenoyltrifluoracetone-trioctylphosphineoxide (Eu-TTA-TOPO) can be easily and efficiently excited using a standard frequency-tripled Nd:YAG laser. The emitted spectrum, with maximum intensity at a wavelength of 614 nm, is shown not to vary strongly with temperature (293-383 K). The decay constant of the phosphorescence, while independent of ambient pressure, decreases by approximately 12 μs/K between 323 and 373 K, with the base level of the decay constant dependent on the used solvent. The complex does not luminesce in the gas or solid state, meaning only the liquid phase is visualized, even in an evaporating spray. By using an internally excited spray containing the phosphorescent complex, the effect of vaporization is shown through the decrease in measured intensity over the length of the spray, together with droplet size measurements using interferometric particle imaging. This study shows that LIP, using the Eu-TTA-TOPO complex, can be used with different solvents, including diesel surrogates. Furthermore, it can be easily handled and used in sprays to investigate spray breakup and evaporation.