WorldWideScience

Sample records for scandium phosphides

  1. 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.)

  2. 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.

  3. Synthesis of ruthenium phosphides

    International Nuclear Information System (INIS)

    Chernogorenko, V.B.; Lynchak, K.A.; Kulik, L.Ya.; Shkaravskij, Yu.F.; Klochkov, L.A.

    1977-01-01

    A method of ampoule synthesis of ruthenium phosphides, Ru 2 P, RuP, and RuP 2 , with stepwise heating of stoichimetric charges in a single-zone furnace is developed. A method for synthesizing ruthenium diphosphide by phosphidization of a ruthenium powder with phosphine at 1150 deg C is worked out. The optimum conditions of its manufacture are found by planning an extremal experiment. Interaction of PH 3 with ruthenium proceeds by the diffusion mechanism and obeys the parabolic law. An extraction-photometric method for determining phosphorus in phosphides is elaborated. Ruthenium phosphides are extremely corrosion-resistant in acids and alkalis. Ru 2 P and RuP exhibit metallic conductivity

  4. Photovoltaic cells employing zinc phosphide

    Science.gov (United States)

    Barnett, Allen M.; Catalano, Anthony W.; Dalal, Vikram L.; Masi, James V.; Meakin, John D.; Hall, Robert B.

    1984-01-01

    A photovoltaic cell having a zinc phosphide absorber. The zinc phosphide can be a single or multiple crystal slice or a thin polycrystalline film. The cell can be a Schottky barrier, heterojunction or homojunction device. Methods for synthesizing and crystallizing zinc phosphide are disclosed as well as a method for forming thin films.

  5. Fatal aluminium phosphide poisoning

    Directory of Open Access Journals (Sweden)

    Meena Mahesh Chand

    2015-06-01

    Full Text Available Aluminium phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide which is commonly used for grain preservation. AlP has currently aroused interest with a rising number of cases in the past four decades due to increased use for agricultural and non-agricultural purposes. Its easy availability in the markets has increased also its misuse for committing suicide. Phosphine inhibits cellular oxygen utilization and can induce lipid peroxidation. Poisoning with AlP has often occurred in attempts to commit suicide, and that more often in adults than in teenagers. This is a case of suicidal consumption of aluminium phosphide by a 32-year-old young medical anesthetist. Toxicological analyses detected aluminium phosphide. We believe that free access of celphos tablets in grain markets should be prohibited by law.

  6. 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)

  7. 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

  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. Lattice Dynamics of Gallium Phosphide

    International Nuclear Information System (INIS)

    Yarnell, J.L.; Warren, J.L.; Wenzel, R.G.; Dean, P.J.

    1968-01-01

    Dispersion curves for phonons propagating in the [100], [110], and [111] directions in gallium phosphide have been measured using a triple-axis neutron diffraction spectrometer operating in the constant-Q mode. The sample was a pseudo-single crystal which was prepared by gluing together 36 single crystal plates of gallium phosphide 1 to 2.5 cm in diameter and ∼0.07 cm thick. The plates were grown epitaxially on substrates of gallium arsenide or gallium phosphide, and aligned individually by neutron diffraction. Rocking curves for eight reflections symmetrically distributed in the plane of the experiment had full widths at half maximum in the range 0.52° - 0.58° and were approximately Gaussian in shape. Gallium phosphide crystallizes in the zinc blende structure. A group theoretic analysis of the lattice dynamics of this structure and a shell model fit to the measured dispersion curves are presented. Various optical properties of gallium phosphide are discussed in terms of the phonon dispersion curves. In particular, the phonons which assist indirect electronic transitions are identified as those at the zone boundary in the [100] direction (symmetry point X) in agreement with theoretical and experimental indications that the extrema of the conduction and valence bands are at X and Γ (center of the zone), respectively. The LO branches lie above the TO branches throughout the Brillouin zone in contradiction to the predictions of Keyes and Mitra. The shell model fit indicates that the charge on the gallium atom is negative. (author)

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. Fabrication of boron-phosphide neutron detectors

    International Nuclear Information System (INIS)

    Fitzsimmons, M.; Pynn, R.

    1997-01-01

    Boron phosphide is a potentially viable candidate for high neutron flux neutron detectors. The authors have explored chemical vapor deposition methods to produce such detectors and have not been able to produce good boron phosphide coatings on silicon carbide substrates. However, semi-conducting quality films have been produced. Further testing is required

  17. Phonon properties of americium phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Arya, B. S., E-mail: bsarya13@yahoo.com [Department of Physics, Govt. Narmada P G College, Hoshangabad -461001 (India); Aynyas, Mahendra [Department of Physics, C. S. A. Govt. P. G. College Sehore-46601 (India); Sanyal, S. P. [Department of Physics, Barkatullah University, Bhopal-462026 (India)

    2016-05-23

    Phonon properties of AmP have been studied by using breathing shell models (BSM) which includes breathing motion of electrons of the Am atoms due to f-d hybridization. The phonon dispersion curves, specific heat calculated from present model. The calculated phonon dispersion curves of AmP are presented follow the same trend as observed in uranium phosphide. We discuss the significance of this approach in predicting the phonon dispersion curves of these compounds and examine the role of electron-phonon interaction.

  18. 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

  19. 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

  20. 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

  1. 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).

  2. 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)

  3. InP (Indium Phosphide): Into the future

    International Nuclear Information System (INIS)

    Brandhorst, H.W. Jr.

    1989-03-01

    Major industry is beginning to be devoted to indium phosphide and its potential applications. Key to these applications are high speed and radiation tolerance; however the high cost of indium phosphide may be an inhibitor to progress. The broad applicability of indium phosphide to many devices will be discussed with an emphasis on photovoltaics. Major attention is devoted to radiation tolerance and means of reducing cost of devices. Some of the approaches applicable to solar cells may also be relevant to other devices. The intent is to display the impact of visionary leadership in the field and enable the directions and broad applicability of indium phosphide

  4. InP (Indium Phosphide): Into the future

    Science.gov (United States)

    Brandhorst, Henry W., Jr.

    1989-01-01

    Major industry is beginning to be devoted to indium phosphide and its potential applications. Key to these applications are high speed and radiation tolerance; however the high cost of indium phosphide may be an inhibitor to progress. The broad applicability of indium phosphide to many devices will be discussed with an emphasis on photovoltaics. Major attention is devoted to radiation tolerance and means of reducing cost of devices. Some of the approaches applicable to solar cells may also be relevant to other devices. The intent is to display the impact of visionary leadership in the field and enable the directions and broad applicability of indium phosphide.

  5. 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

  6. 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

  7. On melting of boron phosphide under pressure

    OpenAIRE

    Solozhenko, Vladimir; Mukhanov, V. A.

    2015-01-01

    Melting of cubic boron phosphide, BP, has been studied at pressures to 9 GPa using synchrotron X-ray diffraction and electrical resistivity measurements. It has been found that above 2.6 GPa BP melts congruently, and the melting curve exhibits negative slope (–60 ± 7 K/GPa), which is indicative of a higher density of the melt as compared to the solid phase.

  8. Mechanism of hydrodenitrogenation on phosphides and sulfides.

    Science.gov (United States)

    Oyama, S Ted; Lee, Yong-Kul

    2005-02-17

    The mechanism of hydrodenitrogenation (HDN) of 2-methylpiperidine was studied over a silica-supported nickel phosphide catalyst (Ni2P/SiO2, Ni/P = 1/2) and a commercial Ni-Mo-S/Al2O3 catalyst in a three-phase trickle-bed reactor operated at 3.1 MPa and 450-600 K. Analysis of the product distribution as a function of contact time indicated that the reaction proceeded in both cases predominantly by a substitution mechanism, with a smaller contribution of an elimination mechanism. Fourier transform infrared spectroscopy (FTIR) of the 2-methylpiperidine indicated that at reaction conditions a piperidinium ion intermediate was formed on both the sulfide and the phosphide. It is concluded that the mechanism of HDN on nickel phosphide is very similar to that on sulfides. The mechanism on the nickel phosphide was also probed by comparing the reactivity of piperidine and several of its derivatives in the presence of 3000 ppm S. The relative elimination rates depended on the structure of the molecules, and followed the sequence: 4-methylpiperidine approximately piperidine > 3-methylpiperidine > 2,6-dimethylpiperidine > 2-methylpiperidine. [Chemical structure: see text] This order of reactivity was not dependent on the number of alpha-H or beta-H atoms in the molecules, ruling out their reaction through a single, simple mechanism. It is likely that the unhindered piperidine molecules reacted by an S(N)2 substitution process and the more hindered 2,6-dimethylpiperidine reacted by an E2 elimination process.

  9. Aluminium phosphide poising: a case report

    International Nuclear Information System (INIS)

    Hirani, S.A.A.; Rahman, A.

    2010-01-01

    This paper reports the case of a family in which three children were presented at Emergency Room (ER) with poisoning after the use of a pesticide at home. Initially, the cases were managed as routine cases of organophosphorus poisoning; however, the death of two children made the health team members realise that the poison's effects were delayed and devastating. Later, the compound was identified as Aluminium Phosphide (ALP), and the life of the last surviving child in the family was saved. (author)

  10. Microwave-assisted synthesis of transition metal phosphide

    Science.gov (United States)

    Viswanathan, Tito

    2014-12-30

    A method of synthesizing transition metal phosphide. In one embodiment, the method has the steps of preparing a transition metal lignosulfonate, mixing the transition metal lignosulfonate with phosphoric acid to form a mixture, and subjecting the mixture to a microwave radiation for a duration of time effective to obtain a transition metal phosphide.

  11. 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.

  12. 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)

  13. 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

  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. 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

  19. 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.)

  20. 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...

  1. 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

  2. A new approach to synthesize supported ruthenium phosphides for hydrodesulfurization

    International Nuclear Information System (INIS)

    Wang, Qingfang; Wang, Zhiqiang; Yin, Xiaoqian; Zhou, Linxi; Zhang, Minghui

    2016-01-01

    Highlights: • We bring out a new method to synthesize noble metal phosphides at low temperature. • Both RuP and Ru_2P were synthesized using triphenylphosphine as phosphorus sources. • Ru_2P was the better active phase for HDS than RuP and metal Ru. • RuP/SiO_2 prepared by new method had better HDS activity to that by TPR method. - Abstract: Supported noble metal ruthenium phosphides were synthesized by one-step H_2-thermal treatment method using triphenylphosphine (TPP) as phosphorus sources at low temperatures. Two phosphides RuP and Ru_2P can be prepared by this method via varying the molar ratio of metal salt and TPP. The as-prepared phosphides were characterized by X-ray powder diffraction (XRD), low-temperature N_2 adsorption, CO chemisorption and transmission electronic microscopy (TEM). The supported ruthenium phosphides prepared by new method and conventional method together with contradistinctive metallic ruthenium were evaluated in hydrodesulfurization (HDS) of dibenzothiophene (DBT). The catalytic results showed that metal-rich Ru_2P was the better active phase for HDS than RuP and metal Ru. Besides this, ruthenium phosphide catalyst prepared by new method exhibited superior HDS activity to that prepared by conventional method.

  3. A new approach to synthesize supported ruthenium phosphides for hydrodesulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qingfang [Tianjin Key Laboratory of Water Environment and Resources, Tianjin Normal University, Tianjin 300387 (China); Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071 (China); Wang, Zhiqiang [Tianjin Key Laboratory of Water Environment and Resources, Tianjin Normal University, Tianjin 300387 (China); Yin, Xiaoqian; Zhou, Linxi [Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071 (China); Zhang, Minghui, E-mail: zhangmh@nankai.edu.cn [Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071 (China); College of Chemistry and Environmental Science, Kashgar University, Kashgar 844006 (China)

    2016-02-15

    Highlights: • We bring out a new method to synthesize noble metal phosphides at low temperature. • Both RuP and Ru{sub 2}P were synthesized using triphenylphosphine as phosphorus sources. • Ru{sub 2}P was the better active phase for HDS than RuP and metal Ru. • RuP/SiO{sub 2} prepared by new method had better HDS activity to that by TPR method. - Abstract: Supported noble metal ruthenium phosphides were synthesized by one-step H{sub 2}-thermal treatment method using triphenylphosphine (TPP) as phosphorus sources at low temperatures. Two phosphides RuP and Ru{sub 2}P can be prepared by this method via varying the molar ratio of metal salt and TPP. The as-prepared phosphides were characterized by X-ray powder diffraction (XRD), low-temperature N{sub 2} adsorption, CO chemisorption and transmission electronic microscopy (TEM). The supported ruthenium phosphides prepared by new method and conventional method together with contradistinctive metallic ruthenium were evaluated in hydrodesulfurization (HDS) of dibenzothiophene (DBT). The catalytic results showed that metal-rich Ru{sub 2}P was the better active phase for HDS than RuP and metal Ru. Besides this, ruthenium phosphide catalyst prepared by new method exhibited superior HDS activity to that prepared by conventional method.

  4. Metal Phosphides and Phosphates-based Electrodes for Electrochemical Supercapacitors.

    Science.gov (United States)

    Li, Xin; Elshahawy, Abdelnaby M; Guan, Cao; Wang, John

    2017-10-01

    Phosphorus compounds, such as metal phosphides and phosphates have shown excellent performances and great potential in electrochemical energy storage, which are demonstrated by research works published in recent years. Some of these metal phosphides and phosphates and their hybrids compare favorably with transition metal oxides/hydroxides, which have been studied extensively as a class of electrode materials for supercapacitor applications, where they have limitations in terms of electrical and ion conductivity and device stability. To be specific, metal phosphides have both metalloid characteristics and good electric conductivity. For metal phosphates, the open-framework structures with large channels and cavities endow them with good ion conductivity and charge storage capacity. In this review, we present the recent progress on metal phosphides and phosphates, by focusing on their advantages/disadvantages and potential applications as a new class of electrode materials in supercapacitors. The synthesis methods to prepare these metal phosphides/phosphates are looked into, together with the scientific insights involved, as they strongly affect the electrochemical energy storage performance. Particular attentions are paid to those hybrid-type materials, where strong synergistic effects exist. In the summary, the future perspectives and challenges for the metal phosphides, phosphates and hybrid-types are proposed and discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Cavity optomechanics in gallium phosphide microdisks

    International Nuclear Information System (INIS)

    Mitchell, Matthew; Barclay, Paul E.; Hryciw, Aaron C.

    2014-01-01

    We demonstrate gallium phosphide (GaP) microdisk optical cavities with intrinsic quality factors >2.8 × 10 5 and mode volumes 3 , and study their nonlinear and optomechanical properties. For optical intensities up to 8.0 × 10 4 intracavity photons, we observe optical loss in the microcavity to decrease with increasing intensity, indicating that saturable absorption sites are present in the GaP material, and that two-photon absorption is not significant. We observe optomechanical coupling between optical modes of the microdisk around 1.5 μm and several mechanical resonances, and measure an optical spring effect consistent with a theoretically predicted optomechanical coupling rate g 0 /2π∼30 kHz for the fundamental mechanical radial breathing mode at 488 MHz

  6. 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

  7. 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

  8. 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

  9. A Rare but Potentially Fatal Poisoning; Aluminum Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Orkun Tolunay

    2017-04-01

    Full Text Available Phosphide, a very toxic gas, is used in our country as aluminium phosphide tablets impregnated in clay. It is widely used since it has a very high diffusion capacity, whereby it can eradicate all living creatures in any form of their life cycle and does not leave any remnants in agricultural products. Aluminum phosphide poisoning is among intoxications for which there are still no true antidotes. Mortality rate varies between 30% and 100%. This paper presents a case of aluminum phosphide poisoning caused by the uncompleted suicide attempt. A 14-year-old girl, who swallowed aluminum phosphate tablets, was brought to the emergency department with the complaints of nausea and vomiting. The patient was treated with gastric lavage and activated charcoal. Since the patient ingested a lethal amount of aluminum phosphide, she was referred to the pediatric intensive care unit. The patient was discharged in stable condition after supportive care and monitoring. Specific antidotes are life-saving in poisonings. However, this case was presented to show how general treatment principles and quick access to health services affect the result of treatment. Also, we aimed to highlight the uncontrolled selling of aluminum phosphate, which results in high mortality rates in case of poisoning.

  10. Predictors of Poor Prognosis in Aluminum Phosphide Intoxication

    Directory of Open Access Journals (Sweden)

    Fakhredin Taghaddosi Nejad

    2012-05-01

    Full Text Available Background: Aluminum phosphide as a fumigant is extensively used for wheat preservation from rodents and bugs especially in silos worldwide. There is increasing number of acute intoxication with this potentially lethal compound because of its easy availability. We have tried to locate predictors of poor prognosis in patients with aluminum phosphide intoxication in order to find patients who need more strict medical cares. Methods: All cases of aluminum phosphide intoxication that had been referred to our hospital during April 2008 to March 2010 were studied by their medical dossiers. Pertinent data including vital signs, demographic features, clinical and lab findings, and incidence of any complication were collected and analyzed by the relevant statistical methods. Results: Sixty seven cases of aluminum phosphide intoxication were included in the study. 44.8% of them were male. 97% of cases were suicidal. Mean amount of ingestion was 1.23+/- 0.71 tablets. Mortality rate was 41.8%. ECG abnormality and need for mechanical ventilation had negative relation with outcome. Conclusion: Correlation between some findings and complications with outcome in aluminum phosphide intoxication can be used as guidance for risk assessment and treatment planning in the patients.

  11. 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

  12. 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.)

  13. 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

  14. 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.

  15. Acute aluminium phosphide poisoning, what is new?

    Directory of Open Access Journals (Sweden)

    Yatendra Singh

    2014-01-01

    Full Text Available Aluminium phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide that is commonly used for grain preservation. AlP has currently generated interest with increasing number of cases in the past four decades because of its increased use for agricultural and nonagricultural purposes, and also its easy availability in the markets has led to its increased misuse to commit suicide. Ingestion is usually suicidal in intent, uncommonly accidental and rarely homicidal. The poison affects all systems, shock, cardiac arrhythmias with varied ECG changes and gastrointestinal features being the most prominent. Diagnosis is made on the basis of clinical suspicion, a positive silver nitrate paper test to phosphine, and gastric aspirate and viscera biochemistry. Treatment includes early gastric lavage with potassium permanganate or a combination of coconut oil and sodium bicarbonate, administration of charcoal and palliative care. Specific therapy includes intravenous magnesium sulphate and oral coconut oil. Unfortunately, the lack of a specific antidote Results in very high mortality and the key to treatment lies in rapid decontamination and institution of resuscitative measures. This article aims to identify the salient features and mechanism of AlP poisoning along with its management strategies and prognostic variables.

  16. Fabrication challenges for indium phosphide microsystems

    International Nuclear Information System (INIS)

    Siwak, N P; Fan, X Z; Ghodssi, R

    2015-01-01

    From the inception of III–V microsystems, monolithically integrated device designs have been the motivating drive for this field, bringing together the utility of single-chip microsystems and conventional fabrication techniques. Indium phosphide (InP) has a particular advantage of having a direct bandgap within the low loss telecommunication wavelength (1550 nm) range, able to support passive waveguiding and optical amplification, detection, and generation depending on the exact alloy of In, P, As, Ga, or Al materials. Utilizing epitaxy, one can envision the growth of a substrate that contains all of the components needed to establish a single-chip optical microsystem, containing detectors, sources, waveguides, and mechanical structures. A monolithic InP MEMS system has, to our knowledge, yet to be realized due to the significant difficulties encountered when fabricating the integrated devices. In this paper we present our own research and consolidate findings from other research groups across the world to give deeper insight into the practical aspects of InP monolithic microsystem development: epitaxial growth of InP-based alloys, etching techniques, common MEMS structures realized in InP, and future applications. We pay special attention to shedding light on considerations that must be taken when designing and fabricating a monolithic InP MEMS device. (topical review)

  17. An update on toxicology of aluminum phosphide

    Directory of Open Access Journals (Sweden)

    Moghadamnia Ali

    2012-09-01

    Full Text Available Abstract Aluminum phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide which is commonly used for grain preservation. In Iran it is known as the “rice tablet”. AlP has currently aroused interest with increasing number of cases in the past four decades due to increased use in agricultural and non-agricultural purposesand also its easy availability in the markets has increased its misuse to commit suicide. Upon contact with moisture in the environment, AlP undergoes a chemical reaction yielding phosphine gas, which is the active pesticidal component. Phosphine inhibits cellular oxygen utilization and can induce lipid peroxidation. It was reported that AlP has a mortality rate more than 50% of intoxication cases. Poisoning with AlP has usually occurred in attempts to suicide. It is a more common case in adults rather than teen agers. In some eastern countries it is a very common agent with rapid action for suicide. Up to date, there is no effective antidote or treatment for its intoxication. Also, some experimental results suggest that magnesium sulfate, N-acetyl cysteine (NAC, glutathione, vitamin C and E, beta-carotenes, coconut oil and melatonin may play an important role in reducing the oxidative outcomes of phosphine. This article reviews the experimental and clinical features of AlP intoxication and tries to suggest a way to encounter its poisoning.

  18. An Update on Toxicology of Aluminum Phosphide

    Directory of Open Access Journals (Sweden)

    Ali Akbar Moghhadamnia

    2012-09-01

    Full Text Available Aluminum phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide which is commonly used for grain preservation. In Iran it is known as the "rice tablet". AlP has currently aroused interest with increasing number of cases in the past four decades due to increased use in agricultural and non-agricultural purposes and also its easy availability in the markets has increased its misuse to commit suicide. Upon contact with moisture in the environment, AlP undergoes a chemical reaction yielding phosphine gas, which is the active pesticidal component. Phosphine inhibits cellular oxygen utilization and can induce lipid peroxidation. It was reported that AlP has a mortality rate more than 50% of intoxication cases. Poisoning with AlP has usually occurred in attempts to suicide. It is a more common case in adults rather than teen agers. In some eastern countries it is a very common agent with rapid action for suicide. Up to date, there is no effective antidote or treatment for its intoxication. Also, some experimental results suggest that magnesium sulfate, N-acetyl cysteine (NAC, glutathione, vitamin C and E, beta-carotenes, coconut oil and melatonin may play an important role in reducing the oxidative outcomes of phosphine. This article reviews the experimental and clinical features of AlP intoxication and tries to suggest a way to encounter its poisoning.

  19. [Severity factors of aluminium phosphide poisoning (Phostoxin)].

    Science.gov (United States)

    Hajouji Idrissi, M; Oualili, L; Abidi, K; Abouqal, R; Kerkeb, O; Zeggwagh, A A

    2006-04-01

    To determine characteristics of acute aluminum phosphide poisoning (AAlPP) and to evaluate its severity factors. Retrospective cohort study. Consecutive cases of AAlPP admitted in medical ICU (Hospital Avicenne, Rabat, Morocco) between January 1992 and December 2002 were studied. AAlPP was identified by history, symptoms and toxicological results. Almost 50 parameters have been collected and compared between survivors and non-survivors groups. Data were analyzed using Fisher exact test and Mann-Whitney test. Twenty-eight patients were enrolled: 17 female and 11 male, average age = 24+/-11 years, SAPS II = 24.4+/-14.5. The ingested dose was 3.3+/-1.8 g. The self-poisoning was observed in 27 cases and delay before hospital admission was 11+/-13 hours. Mean Glasgow coma scale was 14+/-2. Shock was found in 22 (79%) cases. Average pH was 7.1+/-0.4 and bicarbonate concentration was 16.3+/-8.8 mmol/l. The ECG abnormalities were noted in 20 (72%) cases. The average mortality rate was 61%. The prognostic factors were SAPS II (p = 0.031), Apache II (p = 0.037), shock (p = 0.022), ECG abnormalities (p = 0.05), use of vasoactive drugs (p = 0.05) and use of mechanical ventilation (p = 0.003). AAlPP induced a significantly high mortality and haemodynamic disturbances were a risk factor of poor outcome.

  20. Thermal expansion and volumetric changes during indium phosphide melting

    International Nuclear Information System (INIS)

    Glazov, V.M.; Davletov, K.; Nashel'skij, A.Ya.; Mamedov, M.M.

    1977-01-01

    The results of the measurements of a thermal expansion were summed up at various temperatures as a diagram in coordinates (Δ 1/1) approximately F(t). It was shown that an appreciable deviation of the relationship (Δ1/1) approximately f(t) from the linear law corresponded to a temperature of 500-550 deg C. It was noted that the said deviation was related to an appreciable thermal decomposition of indium phosphide as temperature increased. The strength of the inter-atomic bond of indium phosphide was calculated. Investigated were the volumetric changes of indium phosphide on melting. The resultant data were analyzed with the aid of the Clausius-Clapeyron equation

  1. A Suicide Attempt Using Zinc Phosphide (A Case Study

    Directory of Open Access Journals (Sweden)

    Aysenur Sumer Coskun

    2013-10-01

    Full Text Available Zinc phosphide is a toxin that is added to wheat for use in rodent control and is the active ingredient of rodenticide. A 17 year-old male attempted suicide by drinking pesticide [Zinc PHOSPHIDE (Zn3P2] and was subsequently admitted to the emergency department: the patient’s general condition was poor, he was unconscious and vomiting, the skin had a garlic odor and advanced acidosis was present. The patient was treated symptomatically, followed by mechanical ventilation, and was transferred to a psychiatric clinic on the fifth day.

  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. Polyserositis: An Unusual Complication of Aluminum Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Ashish Bhalla

    2012-12-01

    Full Text Available   Background: Aluminum phosphide is the common cause of poisoning in adults in India, with a very high case fatality ratio. We studied five patients of aluminum phosphide poisoning with polyserositis. Methods: We enrolled all patients with aluminum phosphide poisoning presenting to emergency medical department, at a tertiary care hospital in northwestern India from January to July 2006. These patients were managed according to a standard treatment protocol and their complications were recorded. Results: During the study period, total of 35 patients were admitted with 57.5% mortality in the first 12 hours. Among the rest, 5 patients were found to develop polyserositis. All these patients had severe hypotension at presentation and developed respiratory distress requiring mechanical ventilation after an average stay of 3.8 days post-ingestion. They were managed conservatively and four of them were discharged from the hospital after the average stay of 10 days. Conclusion: In this case series, features of polyserositis (pleural effusion, ascites and pericardial effusion were found in 15% patients of severe aluminum phosphide poisoning. We postulate systemic capillary leak syndrome, secondary to mitochondrial damage in the endothelium, as a possible mechanism.        

  5. Wurtzite gallium phosphide has a direct-band gap

    NARCIS (Netherlands)

    Assali, S.; Zardo, I.; Plissard, S.; Verheijen, M.A.; Haverkort, J.E.M.; Bakkers, E.P.A.M.

    2013-01-01

    Gallium Phosphide (GaP) with the normal cubic crystal structure has an indirect band gap, which severely limits the emission efficiency. We report the fabrication of GaP nanowires with pure hexagonal crystal structure and demonstrate the direct nature of the band gap. We observe strong

  6. 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

  7. 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

  8. 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)

  9. Rational Design of Zinc Phosphide Heterojunction Photovoltaics

    Science.gov (United States)

    Bosco, Jeffrey Paul

    The prospect of terawatt-scale electricity generation using a photovoltaic (PV) device places strict requirements on the active semiconductor optoelectronic properties and elemental abundance. After reviewing the constraints placed on an ``earth-abundant'' solar absorber, we find zinc phosphide (α-Zn 3P2) to be an ideal candidate. In addition to its near-optimal direct band gap of 1.5 eV, high visible-light absorption coefficient (>10. 4cm-1), and long minority-carrier diffusion length (>5 μm), Zn3P 2 is composed of abundant Zn and P elements and has excellent physical properties for scalable thin-film deposition. However, to date, a Zn 3P2 device of sufficient efficiency for commercial applications has not been demonstrated. Record efficiencies of 6.0% for multicrystalline and 4.3% for thin-film cells have been reported, respectively. Performance has been limited by the intrinsic p-type conductivity of Zn3P 2 which restricts us to Schottky and heterojunction device designs. Due to our poor understanding of Zn3P2 interfaces, an ideal heterojunction partner has not yet been found. The goal of this thesis is to explore the upper limit of solar conversion efficiency achievable with a Zn3P2 absorber through the design of an optimal heterojunction PV device. To do so, we investigate three key aspects of material growth, interface energetics, and device design. First, the growth of Zn3P2 on GaAs(001) is studied using compound-source molecular-beam epitaxy (MBE). We successfully demonstrate the pseudomorphic growth of Zn3P2 epilayers of controlled orientation and optoelectronic properties. Next, the energy-band alignments of epitaxial Zn3P2 and II-VI and III-V semiconductor interfaces are measured via high-resolution x-ray photoelectron spectroscopy in order to determine the most appropriate heterojunction partner. From this work, we identify ZnSe as a nearly ideal n-type emitter for a Zn3P 2 PV device. Finally, various II-VI/Zn3P2 heterojunction solar cells designs are

  10. 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

  11. 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

  12. 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

  13. Radiation induced traps of zinc phosphate and phosphide

    International Nuclear Information System (INIS)

    Murali, K.R.; Rao, D.R.

    1980-01-01

    Thermoluminescence (TL) glow curve (TGC) method has been used to study the traps produced by X-irradiation in Zn 3 (PO 4 ) 2 and Zn 3 P 2 . Prominent TL glow peaks were observed at 100 0 and 360 0 C for zinc phosphate while for zinc phosphide only one glow peak at 245 0 C was observed, and in the latter case the TL output was in general quite low compared to zinc phosphate. The TL spectra for both the glow peaks of zinc phosphate indicated emission band in the region around 560 nm, while for zinc phosphide the emission occurred at 575 nm (in the temperature region 200-270 0 C). The low temperature glow peaks below 270 0 C were less stable compared to those above 300 0 C and were completely destroyed when the irradiated samples were stored in darkness for 24 hr at room temperature. Shining by 470 nm light however produced preferential bleaching of the two TL peaks at 100 and 360 0 C with no effect on the 245 0 C glow peak of zinc phosphide. It is concluded that during heat treatment large numbers of Zn-vacancies are formed due to which complexes like Zn-P are produced by irradiation and the TL traps destroyed in a radiative recombination process are related with these complexes. (author)

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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

  20. Indium phosphide space solar cell research: Where we are and where we are going

    Science.gov (United States)

    Jain, R. K.; Flood, D. J.; Weinberg, Irving

    1995-01-01

    Indium phosphide is considered to be a strong contender for many photovoltaic space applications because of its radiation resistance and its potential for high efficiency. An overview of recent progress is presented, and possible future research directions for indium phosphide space solar cells are discussed. The topics considered include radiation damage studies and space flight experiments.

  1. 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.

  2. 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)

  3. 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.

  4. 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

  5. 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.

  6. 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)

  7. 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.)

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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

  13. Low temperature synthesis of ternary metal phosphides using plasma for asymmetric supercapacitors

    KAUST Repository

    Liang, Hanfeng; Xia, Chuan; Jiang, Qiu; Gandi, Appala; Schwingenschlö gl, Udo; Alshareef, Husam N.

    2017-01-01

    We report a versatile route for the preparation of metal phosphides using PH plasma for supercapacitor applications. The high reactivity of plasma allows rapid and low temperature conversion of hydroxides into monometallic, bimetallic, or even more

  14. Solubility limit and precipitation kinetics of iron-phosphide in ferritic iron

    International Nuclear Information System (INIS)

    Suzuki, Shigeru

    1992-01-01

    The solubility limit of iron-phosphide in ferritic iron was examined with electrical resistivity measurements by using the relationship between resistivity and the amount of dissolved phosphorous. The temperature dependence of the solubility obtained was in good agreement with previous results. The kinetics of precipitation of the phosphide from a supersaturated Fe-3.75 at.% P alloy was also investigated with changes of the resistivity by isochronal and isothermal annealing. The activation energy for the precipitation process of the phosphide was about 2.6 eV. Diffusivities of phosphorus were estimated from the annealing behaviour and the morphology of the precipitates, which were comparable to those obtained with the tracer method previously. This suggests that the precipitation process of phosphide is rate controlled by diffusion of phosphorus in ferritic iron-phosphorus alloys. (orig.) [de

  15. 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

  16. 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

  17. Aluminum Phosphide; the Most Fatal Rodenticide and Fungicide

    International Nuclear Information System (INIS)

    Afshari, R.

    2007-01-01

    Introduction: Aluminum phosphide (AP) is a fumigate agent, which is also used to control rodents and pests in grain storage facilities. This agent is commonly used in low income and agricultural communities. AP is easily available, cheap and highly toxic. Ingestion of even half a fresh tablet invariably results in death. Its suicidal or accidental poisoning is a medical emergency, while in some low income countries it reaches to more than two third of poisoning deaths. Methods: PubMed was systematically searched (December 2006) for articles related to aluminium phosphide poisoning. 24 articles were finally included. Mechanism of action; AP on exposure to moisture, liberates highly toxic gas, phosphine. In animal and human models AP rapidly inhibits cytochrome-c oxidase leading to inhibition of mitochondrial oxidative phosphorylation and inhibits mitochondrial respiration and has cytotoxic action. Clinical Findings: Initial findings of intoxication may be nonspecific and transient. The symptoms may resolve within several hours after removal from exposure. It, however, produces phosphine gas, which is a mitochondrial poison. Its manufacturing and application pose risks of inhalation of phosphine. CNS; GCS is fine at the beginning. Biochemistry; Metabolic acidosis and liver dysfunction are reported. Shock is frequent. Respiratory Tract; Acute dyspnoea, hypotension, bradycardia and other signs of intoxication were also stated. Gastrointestinal; Reported short-segment esophageal strictures in the upper and mid esophagus, successfully managed by endoscopic dilatation. In sub-chronic use, degenerative changes in liver, heart and kidney of rabbits are reported. Cardiovascular; The ECG abnormalities are common and include hypotension, bradycardia, ST-T changes, Supraventricular tachycardia, ventricular ectopics, life threatening ventricular tachycardia, ventricular fibrillation, atrial flutter/fibrillation, variable degrees of heart block and toxic myocarditis. Haematologic

  18. Changes in Some Hematology Parameters in poisoning with Rice Tablet (Aluminum Phosphide)

    OpenAIRE

    Farshid Fayyaz (PhD)

    2015-01-01

    Background and Objective: Aluminum Phosphide (ALP) is a solid non-organic phosphide with dark gray or dark yellow crystals. It reacts with stomach acid after ingestion and causes phosphine gas to be released. It is thought that phosphine causes toxicity from enzymatic interference and may even lead to cell death. This study aimed to investigate the effects of poisoning with rice tablet on levels of platelets, hemoglobin, white blood cells. Methods: The clinical records of 67 cases of acute...

  19. Solar cells with gallium phosphide/silicon heterojunction

    Science.gov (United States)

    Darnon, Maxime; Varache, Renaud; Descazeaux, Médéric; Quinci, Thomas; Martin, Mickaël; Baron, Thierry; Muñoz, Delfina

    2015-09-01

    One of the limitations of current amorphous silicon/crystalline silicon heterojunction solar cells is electrical and optical losses in the front transparent conductive oxide and amorphous silicon layers that limit the short circuit current. We propose to grow a thin (5 to 20 nm) crystalline Gallium Phosphide (GaP) by epitaxy on silicon to form a more transparent and more conducting emitter in place of the front amorphous silicon layers. We show that a transparent conducting oxide (TCO) is still necessary to laterally collect the current with thin GaP emitter. Larger contact resistance of GaP/TCO increases the series resistance compared to amorphous silicon. With the current process, losses in the IR region associated with silicon degradation during the surface preparation preceding GaP deposition counterbalance the gain from the UV region. A first cell efficiency of 9% has been obtained on ˜5×5 cm2 polished samples.

  20. Optical properties of indium phosphide nanowire ensembles at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Lohn, Andrew J; Onishi, Takehiro; Kobayashi, Nobuhiko P [Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064 (United States); Nanostructured Energy Conversion Technology and Research (NECTAR), Advanced Studies Laboratories, University of California Santa Cruz-NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2010-09-03

    Ensembles that contain two types (zincblende and wurtzite) of indium phosphide nanowires grown on non-single crystalline surfaces were studied by micro-photoluminescence and micro-Raman spectroscopy at various low temperatures. The obtained spectra are discussed with the emphasis on the effects of differing lattice types, geometries, and crystallographic orientations present within an ensemble of nanowires grown on non-single crystalline surfaces. In the photoluminescence spectra, a typical Varshni dependence of band gap energy on temperature was observed for emissions from zincblende nanowires and in the high temperature regime energy transfer from excitonic transitions and band-edge transitions was identified. In contrast, the photoluminescence emissions associated with wurtzite nanowires were rather insensitive to temperature. Raman spectra were collected simultaneously from zincblende and wurtzite nanowires coexisting in an ensemble. Raman peaks of the wurtzite nanowires are interpreted as those related to the zincblende nanowires by a folding of the phonon dispersion.

  1. AC surface photovoltage of indium phosphide nanowire networks

    Energy Technology Data Exchange (ETDEWEB)

    Lohn, Andrew J.; Kobayashi, Nobuhiko P. [California Univ., Santa Cruz, CA (United States). Baskin School of Engineering; California Univ., Santa Cruz, CA (US). Nanostructured Energy Conversion Technology and Research (NECTAR); NASA Ames Research Center, Moffett Field, CA (United States). Advanced Studies Laboratories

    2012-06-15

    Surface photovoltage is used to study the dynamics of photogenerated carriers which are transported through a highly interconnected three-dimensional network of indium phosphide nanowires. Through the nanowire network charge transport is possible over distances far in excess of the nanowire lengths. Surface photovoltage was measured within a region 10.5-14.5 mm from the focus of the illumination, which was chopped at a range of frequencies from 15 Hz to 30 kHz. Carrier dynamics were modeled by approximating the nanowire network as a thin film, then fitted to experiment suggesting diffusion of electrons and holes at approximately 75% of the bulk value in InP but with significantly reduced built-in fields, presumably due to screening by nanowire surfaces. (orig.)

  2. Optical properties of indium phosphide nanowire ensembles at various temperatures

    International Nuclear Information System (INIS)

    Lohn, Andrew J; Onishi, Takehiro; Kobayashi, Nobuhiko P

    2010-01-01

    Ensembles that contain two types (zincblende and wurtzite) of indium phosphide nanowires grown on non-single crystalline surfaces were studied by micro-photoluminescence and micro-Raman spectroscopy at various low temperatures. The obtained spectra are discussed with the emphasis on the effects of differing lattice types, geometries, and crystallographic orientations present within an ensemble of nanowires grown on non-single crystalline surfaces. In the photoluminescence spectra, a typical Varshni dependence of band gap energy on temperature was observed for emissions from zincblende nanowires and in the high temperature regime energy transfer from excitonic transitions and band-edge transitions was identified. In contrast, the photoluminescence emissions associated with wurtzite nanowires were rather insensitive to temperature. Raman spectra were collected simultaneously from zincblende and wurtzite nanowires coexisting in an ensemble. Raman peaks of the wurtzite nanowires are interpreted as those related to the zincblende nanowires by a folding of the phonon dispersion.

  3. Thermoelectric properties of boron and boron phosphide CVD wafers

    Energy Technology Data Exchange (ETDEWEB)

    Kumashiro, Y.; Yokoyama, T.; Sato, A.; Ando, Y. [Yokohama National Univ. (Japan)

    1997-10-01

    Electrical and thermal conductivities and thermoelectric power of p-type boron and n-type boron phosphide wafers with amorphous and polycrystalline structures were measured up to high temperatures. The electrical conductivity of amorphous boron wafers is compatible to that of polycrystals at high temperatures and obeys Mott`s T{sup -{1/4}} rule. The thermoelectric power of polycrystalline boron decreases with increasing temperature, while that of amorphous boron is almost constant in a wide temperature range. The weak temperature dependence of the thermal conductivity of BP polycrystalline wafers reflects phonon scattering by grain boundaries. Thermal conductivity of an amorphous boron wafer is almost constant in a wide temperature range, showing a characteristic of a glass. The figure of merit of polycrystalline BP wafers is 10{sup -7}/K at high temperatures while that of amorphous boron is 10{sup -5}/K.

  4. Phosphorus Dimerization in Gallium Phosphide at High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lavina, Barbara [High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154, United States; Department of Physics and Astronomy, University of Nevada, Las Vegas, Nevada 89154, United States; Kim, Eunja [Department of Physics and Astronomy, University of Nevada, Las Vegas, Nevada 89154, United States; Cynn, Hyunchae [Lawrence Livermore National Laboratory, Livermore, California 94550, United States; Weck, Philippe F. [Sandia National Laboratories, Albuquerque, New Mexico 87185, United States; Seaborg, Kelly [High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154, United States; Department of Physics and Astronomy, University of Nevada, Las Vegas, Nevada 89154, United States; Siska, Emily [High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154, United States; Meng, Yue [HPCAT, Carnegie Institution of Washington, Argonne, Illinois 60439, United States; Evans, William [Lawrence Livermore National Laboratory, Livermore, California 94550, United States

    2018-02-09

    Using combined experimental and computational approaches, we show that at 43 GPa and 1300 K gallium phosphide adopts the super-Cmcm structure, here indicated with its Pearson notation oS24. First-principles enthalpy calculations demonstrate that this structure is more thermodynamically stable above ~20 GPa than previously proposed polymorphs. Here, in contrast to other polymorphs, the oS24 phase shows a strong bonding differentiation and distorted fivefold coordination geometries of both P atoms. The shortest bond of the phase is a single covalent P–P bond measuring 2.171(11) Å at synthesis pressure. Phosphorus dimerization in GaP sheds light on the nature of the super-Cmcm phase and provides critical new insights into the high-pressure polymorphism of octet semiconductors. Bond directionality and anisotropy explain the relatively low symmetry of this high-pressure phase.

  5. 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 ...

  6. 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

  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. 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.

  9. Novel, high-activity hydroprocessing catalysts: Iron group phosphides

    Science.gov (United States)

    Wang, Xianqin

    A series of iron, cobalt and nickel transition metal phosphides was synthesized by means of temperature-programmed reduction (TPR) of the corresponding phosphates. The same materials, Fe2P, CoP and NO, were also prepared on a silica (SiO2) support. The phase purity of these catalysts was established by x-ray diffraction (XRD), and the surface properties were determined by N2 BET specific surface area (Sg) measurements and CO chemisorption. The activities of the silica-supported catalysts were tested in a three-phase trickle bed reactor for the simultaneous hydrodenitrogenation (HDN) of quinoline and hydrodesulfurization (HDS) of dibenzothiophene using a model liquid feed at realistic conditions (30 atm, 370°C). The reactivity studies showed that the nickel phosphide (Ni2P/SiO2) was the most active of the catalysts. Compared with a commercial Ni-Mo-S/gamma-Al 2O3 catalyst at the same conditions, Ni2P/silica had a substantially higher HDS activity (100% vs. 76%) and HDN activity (82% vs. 38%). Because of their good hydrotreating activity, an extensive study of the preparation of silica supported nickel phosphides, Ni2P/SiO 2, was carried out. The parameters investigated were the phosphorus content and the weight loading of the active phase. The most active composition was found to have a starting synthesis Ni/P ratio close to 1/2, and the best loading of this sample on silica was observed to be 18 wt.%. Extended x-ray absorption fine structure (EXAFS) and x-ray absorption near edge spectroscopy (XANES) measurements were employed to determine the structures of the supported samples. The main phase before and after reaction was found to be Ni2P, but some sulfur was found to be retained after reaction. A comprehensive scrutiny of the HDN reaction mechanism was also made over the Ni2P/SiO2 sample (Ni/P = 1/2) by comparing the HDN activity of a series of piperidine derivatives of different structure. It was found that piperidine adsorption involved an alpha-H activation

  10. Gallium Phosphide Integrated with Silicon Heterojunction Solar Cells

    Science.gov (United States)

    Zhang, Chaomin

    It has been a long-standing goal to epitaxially integrate III-V alloys with Si substrates which can enable low-cost microelectronic and optoelectronic systems. Among the III-V alloys, gallium phosphide (GaP) is a strong candidate, especially for solar cells applications. Gallium phosphide with small lattice mismatch ( 0.4%) to Si enables coherent/pseudomorphic epitaxial growth with little crystalline defect creation. The band offset between Si and GaP suggests that GaP can function as an electron-selective contact, and it has been theoretically shown that GaP/Si integrated solar cells have the potential to overcome the limitations of common a-Si based heterojunction (SHJ) solar cells. Despite the promising potential of GaP/Si heterojunction solar cells, there are two main obstacles to realize high performance photovoltaic devices from this structure. First, the growth of the polar material (GaP) on the non-polar material (Si) is a challenge in how to suppress the formation of structural defects, such as anti-phase domains (APD). Further, it is widely observed that the minority-carrier lifetime of the Si substrates is significantly decreased during epitaxially growth of GaP on Si. In this dissertation, two different GaP growth methods were compared and analyzed, including migration-enhanced epitaxy (MEE) and traditional molecular beam epitaxy (MBE). High quality GaP can be realized on precisely oriented (001) Si substrates by MBE growth, and the investigation of structural defect creation in the GaP/Si epitaxial structures was conducted using high resolution X-ray diffraction (HRXRD) and high resolution transmission electron microscopy (HRTEM). The mechanisms responsible for lifetime degradation were further investigated, and it was found that external fast diffusors are the origin for the degradation. Two practical approaches including the use of both a SiNx diffusion barrier layer and P-diffused layers, to suppress the Si minority-carrier lifetime degradation

  11. Optical and Electrical Characterization of Melt-Grown Bulk Indium Gallium Arsenide and Indium Arsenic Phosphide Alloys

    Science.gov (United States)

    2011-03-01

    spectrum, photoluminescence (PL), and refractive index measurements. Other methods such as infrared imagery and micro probe wavelength dispersing ...States. AFIT/DS/ENP/11-M02 OPTICAL AND ELECTRICAL CHARACTERIZATION OF MELT- GROWN BULK INDIUM GALLIUM ARSENIDE AND INDIUM ARSENIC PHOSPHIDE ...CHARACTERIZATION OF MELT-GROWN BULK INDIUM GALLIUM ARSENIDE AND INDIUM ARSENIC PHOSPHIDE ALLOYS Jean Wei, BS, MS Approved

  12. Phosphidation of Li4Ti5O12 nanoparticles and their electrochemical and biocompatible superiority for lithium rechargeable batteries.

    Science.gov (United States)

    Jo, Mi Ru; Nam, Ki Min; Lee, Youngmin; Song, Kyeongse; Park, Joon T; Kang, Yong-Mook

    2011-11-07

    Phosphidated-Li(4)Ti(5)O(12) shows high capacity with a significantly enhanced kinetics opening new possibilities for ultra-fast charge/discharge of lithium rechargeable batteries. The in vitro cytotoxicity test proves its fabulous cell viability, indicating that the toxicity problem of nanoparticles can be also solved by phosphidation. This journal is © The Royal Society of Chemistry 2011

  13. Optical Properties of Strained Wurtzite Gallium Phosphide Nanowires

    KAUST Repository

    Greil, J.

    2016-06-08

    Wurtzite gallium phosphide (WZ GaP) has been predicted to exhibit a direct bandgap in the green spectral range. Optical transitions, however, are only weakly allowed by the symmetry of the bands. While efficient luminescence has been experimentally shown, the nature of the transitions is not yet clear. Here we apply tensile strain up to 6% and investigate the evolution of the photoluminescence (PL) spectrum of WZ GaP nanowires (NWs). The pressure and polarization dependence of the emission together with a theoretical analysis of strain effects is employed to establish the nature and symmetry of the transitions. We identify the emission lines to be related to localized states with significant admixture of Γ7c symmetry and not exclusively related to the Γ8c conduction band minimum (CBM). The results emphasize the importance of strongly bound state-related emission in the pseudodirect semiconductor WZ GaP and contribute significantly to the understanding of the optoelectronic properties of this novel material.

  14. Scaling Relations for Adsorption Energies on Doped Molybdenum Phosphide Surfaces

    International Nuclear Information System (INIS)

    Fields, Meredith; Tsai, Charlie; Chen, Leanne D.; Abild-Pedersen, Frank; Nørskov, Jens K.; Chan, Karen

    2017-01-01

    Molybdenum phosphide (MoP), a well-documented catalyst for applications ranging from hydrotreating reactions to electrochemical hydrogen evolution, has yet to be mapped from a more fundamental perspective, particularly in the context of transition-metal scaling relations. In this work, we use periodic density functional theory to extend linear scaling arguments to doped MoP surfaces and understand the behavior of the phosphorus active site. The derived linear relationships for hydrogenated C, N, and O species on a variety of doped surfaces suggest that phosphorus experiences a shift in preferred bond order depending on the degree of hydrogen substitution on the adsorbate molecule. This shift in phosphorus hybridization, dependent on the bond order of the adsorbate to the surface, can result in selective bond weakening or strengthening of chemically similar species. As a result, we discuss how this behavior deviates from transition-metal, sulfide, carbide, and nitride scaling relations, and we discuss potential applications in the context of electrochemical reduction reactions.

  15. 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...

  16. 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)

  17. Thermal Properties and Phonon Spectral Characterization of Synthetic Boron Phosphide for High Thermal Conductivity Applications.

    Science.gov (United States)

    Kang, Joon Sang; Wu, Huan; Hu, Yongjie

    2017-12-13

    Heat dissipation is an increasingly critical technological challenge in modern electronics and photonics as devices continue to shrink to the nanoscale. To address this challenge, high thermal conductivity materials that can efficiently dissipate heat from hot spots and improve device performance are urgently needed. Boron phosphide is a unique high thermal conductivity and refractory material with exceptional chemical inertness, hardness, and high thermal stability, which holds high promises for many practical applications. So far, however, challenges with boron phosphide synthesis and characterization have hampered the understanding of its fundamental properties and potential applications. Here, we describe a systematic thermal transport study based on a synergistic synthesis-experimental-modeling approach: we have chemically synthesized high-quality boron phosphide single crystals and measured their thermal conductivity as a record-high 460 W/mK at room temperature. Through nanoscale ballistic transport, we have, for the first time, mapped the phonon spectra of boron phosphide and experimentally measured its phonon mean free-path spectra with consideration of both natural and isotope-pure abundances. We have also measured the temperature- and size-dependent thermal conductivity and performed corresponding calculations by solving the three-dimensional and spectral-dependent phonon Boltzmann transport equation using the variance-reduced Monte Carlo method. The experimental results are in good agreement with that predicted by multiscale simulations and density functional theory, which together quantify the heat conduction through the phonon mode dependent scattering process. Our finding underscores the promise of boron phosphide as a high thermal conductivity material for a wide range of applications, including thermal management and energy regulation, and provides a detailed, microscopic-level understanding of the phonon spectra and thermal transport mechanisms of

  18. 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.

  19. 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.

  20. 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.

  1. First-principles study of the structural and electronic properties of III-phosphides

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Rashid [Centre for High Energy Physics, University of the Punjab, Lahore 54590 (Pakistan)], E-mail: rasofi@hotmail.com; Fazal-e-Aleem [Centre for High Energy Physics, University of the Punjab, Lahore 54590 (Pakistan); Hashemifar, S. Javad; Akbarzadeh, Hadi [Department of Physics, Isfahan University of Technology, Isfahan 84156 (Iran, Islamic Republic of)

    2008-05-01

    We use density functional theory and different forms of the exchange-correlation approximation to calculate the structural and electronic properties of tetrahedrally coordinated III-phosphide semiconductors. The computed results for structural properties using generalized gradient approximation (GGA) agree well with the experimental data. For reliable description of energy band gap values, another form of GGA developed by Engel and Vosko has been applied. As anticipated, boron phosphide was found to be the hardest compound due to the strong B-P covalent bonding.

  2. A CASE REPORT ON ZINC PHOSPHIDE POISONING AND ITS RARE EFFECTS

    Directory of Open Access Journals (Sweden)

    Naga Raghunandan Thota

    2017-02-01

    Full Text Available BACKGROUND Zinc phosphide is widely in use as a rodenticide. After ingestion, it gets converted to phosphine gas, which is subsequently absorbed into the bloodstream through the stomach and the intestines and gets captured by the liver and the lungs. The toxic effects of zinc phosphide poisoning is through the phosphine gas that produces various metabolic and non-metabolic intermediate compounds. Patients develop features of shock, myocarditis, pericarditis, acute pulmonary oedema and congestive heart failure. In this case report, we present a common complication of the poison that manifested earlier than it is depicted in the current literature.

  3. 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

  4. 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.

  5. Acute aluminium phosphide poisoning: Can we predict mortality?

    Directory of Open Access Journals (Sweden)

    Ashu Mathai

    2010-01-01

    Full Text Available In India, acute aluminium phosphide poisoning (AAlPP is a serious health care problem. This study aimed to determine the characteristics of AAlPP and the predictors of mortality at the time of patients′ admission. We studied consecutive admissions of patients with AAlPP admitted to the intensive care unit (ICU between November 2004 and October 2006. We noted 38 parameters at admission to the hospital and the ICU and compared survivor and non-survivor groups. A total of 27 patients were enrolled comprising5 females and 22 males and the mean ingested dose of poison was 0.75 ± 0.745 grams. Hypotension was noted in 24 patients (89% at admission and electrocardiogram abnormalities were noted in 13 patients (48.1%. The mean pH on admission was 7.20 ± 0.14 and the mean bicarbonate concentration was 12.32 ± 5.45 mmol/ L. The mortality from AAlPP was 59.3%. We found the following factors to be associated with an increased risk of mortality: a serum creatinine concentration of more than 1.0 mg % (P = 0.01, pH value less than 7.2 (P = 0.014, serum bicarbonate value less than 15 mmol/L (P = 0.048, need for mechanical ventilation (P = 0.045, need for vasoactive drugs like dobutamine (P = 0.027 and nor adrenaline (P = 0.048 and a low APACHE II score at admission (P = 0.019. AAlPP causes high mortality primarily due to early haemodynamic failure and multi-organ dysfunction

  6. Frequency of Cardiac Arrhythmias in Patients with Aluminum Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Umair Aziz

    2015-12-01

    Full Text Available Background: Cardiac failure is the major lethal consequence of aluminum phosphide (AlP poisoning. This study was designed to determine the frequency of cardiac arrhythmias in patients with AlP poisoning. Methods: In this prospective cross-sectional study, patients with definitive history of AlP poisoning treated at emergency department of Allied Hospital Faisalabad, Faisalabad, Pakistan, from July 2013 to November 2014 were included. On admission, twelve-lead electrocardiogram (ECG was performed for all patients. During admission, all patients underwent continuous cardiac monitoring using a cardiac monitor. If an arrhythmia was suspected on the cardiac monitor, another ECG was obtained immediately.  Results: During the study period, 100 patients with AlP poisoning (63% men were treated at Allied Hospital Faisalabad. Mean age of the patients was 26.7 ± 7.9 years ranging from 16 to 54 years. Tachycardia was detected in 68 patients and bradycardia in 12 patients. Hypotension was observed in 75 patients. Eighty patients developed cardiac arrhythmia. The most frequent arrhythmia was atrial fibrillation (31% of patients followed by ventricular fibrillation (20%, ventricular tachycardia (17%, 3rd degree AV block (7% and 2nd degree AV block (5%. In total, 78 patients died, depicting a 78% mortality rate following wheat pill poisoning. Among those who died, seventy-one patients had cardiac arrhythmia. Comparison of death rate between patients with and without cardiac arrhythmia showed a significant difference (71/80 (88.8% vs. 7/20 (35%; P < 0.001.  Conclusion: Wheat pill poisoning causes a very high mortality, and circulatory collapse is the major cause of death among these patients. Most of the patients with AlP poisoning develop cardiac arrhythmias which are invariably life threatening. Early detection of cardiac disorders and proper management of arrhythmias may reduce mortalities.

  7. Aluminium Phosphide Poisoning: Two Pediatric Patients and Two Different Clinical Outcomes

    Directory of Open Access Journals (Sweden)

    Faruk Ekinci

    2017-08-01

    Full Text Available Aluminium phosphide is an insecticide that turns into a quite toxic gas called phosphine when contacts with gastric fluids. Aluminium phosphide poisoning causes severe metabolic acidosis, acute respiratory distress syndrome and multi-organ failure with cardiogenic shock. Our first case was an-18-year-old girl admitted to our emergency department two hours after ingestion of one tablet containing 500 mg aluminium phosphide in a suicide attempt. Venoarterial extracorporeal membrane oxygenation was started one hour after initiation of inotropic agents. Despite improvement in hemodynamic status, she developed refractory arrhythmias at the12th hour and she died 22 hours after admission. The second case was a two-year-old girl who was admitted to our emergency department because of observing a piece of aluminum phosphide 500 mg tablet broken in her mouth. Her vital signs were stable in the follow-up. The patient who had no problems in the follow-up was discharged at 48 hours.

  8. Novel p-n heterojunction copper phosphide/cuprous oxide photocathode for solar hydrogen production.

    Science.gov (United States)

    Chen, Ying-Chu; Chen, Zhong-Bo; Hsu, Yu-Kuei

    2018-08-01

    A Copper phosphide (Cu 3 P) micro-rod (MR) array, with coverage by an n-Cu 2 O thin layer by electrodeposition as a photocathode, has been directly fabricated on copper foil via simple electro-oxidation and phosphidation for photoelectrochemical (PEC) hydrogen production. The morphology, structure, and composition of the Cu 3 P/Cu 2 O heterostructure are systematically analyzed using a scanning electron microscope (SEM), X-ray diffraction and X-ray photoelectron spectra. The PEC measurements corroborate that the p-Cu 3 P/n-Cu 2 O heterostructural photocathode illustrates efficient charge separation and low charge transfer resistance to achieve the highest photocurrent of 430 μA cm -2 that is greater than other transition metal phosphide materials. In addition, a detailed energy diagram of the p-Cu 3 P/n-Cu 2 O heterostructure was investigated using Mott-Schottky analysis. Our study paves the way to explore phosphide-based materials in a new class for solar energy applications. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Low temperature synthesis of ternary metal phosphides using plasma for asymmetric supercapacitors

    KAUST Repository

    Liang, Hanfeng

    2017-04-06

    We report a versatile route for the preparation of metal phosphides using PH plasma for supercapacitor applications. The high reactivity of plasma allows rapid and low temperature conversion of hydroxides into monometallic, bimetallic, or even more complex nanostructured phosphides. These same phosphides are much more difficult to synthesize by conventional methods. Further, we present a general strategy for significantly enhancing the electrochemical performance of monometallic phosphides by substituting extrinsic metal atoms. Using NiCoP as a demonstration, we show that the Co substitution into NiP not only effectively alters the electronic structure and improves the intrinsic reactivity and electrical conductivity, but also stabilizes Ni species when used as supercapacitor electrode materials. As a result, the NiCoP nanosheet electrodes achieve high electrochemical activity and good stability in 1 M KOH electrolyte. More importantly, our assembled NiCoP nanoplates//graphene films asymmetric supercapacitor devices can deliver a high energy density of 32.9 Wh kg at a power density of 1301 W kg, along with outstanding cycling performance (83% capacity retention after 5000 cycles at 20 A g). This activity outperforms most of the NiCo-based materials and renders the NiCoP nanoplates a promising candidate for capacitive storage devices.

  10. Peculiarities of electrooptical characteristics of gallium phosphide light-emitting diodes in high injection level conditions

    Directory of Open Access Journals (Sweden)

    O. M. Hontaruk

    2015-04-01

    Full Text Available Electroluminescence of green N-doped gallium phosphide light-emitting diodes was studied. The negative differential resistance region in the current-voltage characteristics was found at low temperature (Т ≤ 90 К. Possible reason of this phenomenon is the redistribution of recombinational flows between annihilation channels on isolated nitrogen atoms and annihilation channel on the NN1 pairs.

  11. Effect of aluminium phosphide on some metabolites of the liver and ...

    African Journals Online (AJOL)

    Aluminium phosphide induced changes in some metabolic parameters in Parophiocephalus obscurus were assessed. Parophiocephalus obscurus (mean length, 18.00±0.09cm and mean weight, 65.03±0.03g) were acclimatized to laboratory condition for 10 days and then exposed to varying sublethal concentrations of ...

  12. Synthesis and catalytic activity of the metastable phase of gold phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Fernando, Deshani; Nigro, Toni A.E.; Dyer, I.D. [Department of Chemistry, 107 Physical Sciences I, Oklahoma State University, Stillwater, OK 74078 (United States); Alia, Shaun M.; Pivovar, Bryan S. [Chemical and Materials Science Center, National Renewable Energy Laboratory, Golden, CO 80401 (United States); Vasquez, Yolanda, E-mail: yolanda.vasquez@okstate.edu [Department of Chemistry, 107 Physical Sciences I, Oklahoma State University, Stillwater, OK 74078 (United States)

    2016-10-15

    Recently, transition metal phosphides have found new applications as catalysts for the hydrogen evolution reaction that has generated an impetus to synthesize these materials at the nanoscale. In this work, Au{sub 2}P{sub 3} was synthesized utilizing the high temperature decomposition of tri-n-octylphosphine as a source of elemental phosphorous. Gold nanorods were used as morphological templates with the aim of controlling the shape and size of the resulting gold phosphide particles. We demonstrate that the surface capping ligand of the gold nanoparticle precursors can influence the purity and extent to which the gold phosphide phase will form. Gold nanorods functionalized with 1-dodecanethiol undergo digestive ripening to produce discrete spherical particles that exhibit reduced reactivity towards phosphorous, resulting in low yields of the gold phosphide. In contrast, gold phosphide was obtained as a phase pure product when cetyltrimethylammonium bromide functionalized gold nanorods are used instead. The Au{sub 2}P{sub 3} nanoparticles exhibited higher activity than polycrystalline gold towards the hydrogen evolution reaction. - Graphical abstract: Au{sub 2}P{sub 3} was synthesized utilizing the high temperature decomposition of tri-n-octylphosphine as a source of elemental phosphorous and gold nanoparticles as reactants. We demonstrate that the surface capping ligand of the gold nanoparticle precursors influence the purity and extent to which the Au{sub 2}P{sub 3} phase will form. Gold nanorods functionalized with 1-dodecanethiol undergo digestive ripening to produce discrete spherical particles that exhibit reduced reactivity towards phosphorous, resulting in low yields of the gold phosphide. In contrast, gold phosphide was obtained as a phase pure product when cetyltrimethylammonium bromide functionalized gold nanoparticles are used instead. The Au{sub 2}P{sub 3} nanoparticles exhibited higher activity than polycrystalline gold towards the hydrogen evolution

  13. Zinc phosphide toxicity with a trial of tranexamic acid in its management

    Directory of Open Access Journals (Sweden)

    Abdel Rahman M. El Naggar

    2011-04-01

    Full Text Available Zinc phosphide is a highly effective rodenticide used widely to protect grain in stores and domestically to kill rodents. Acute poisoning may be direct by ingestion or indirect through accidental inhalation of phosphine gas generated during its use. This study aims to identify the patterns of intoxication with zinc phosphide among Egyptian patients admitted to the National Egyptian Center of Clinical and Environmental Toxicological Research (NECTR; to study the role of antifibrinolytics in management of zinc phosphide toxicity; and to publish the results of the study, which include recommendations for action towards planning prevention and education programs. The study provides descriptive data and analysis of 188 cases admitted to the NECTR with acute zinc phosphide poisoning over a period of 22 months. Results show that poisoning is more common among females (60.6% of cases than males (39.4%; the mean age is nearly 21 years old. The most common cause of poisoning is suicidal attempts (83.6% followed by accidental exposure (16.4%. The most common causative factors that lead to self-poisoning are marital disharmony, economic hardship, social problems and scolding from other family members. Signs and symptoms of toxicity include gastrointestinal disturbances, respiratory compromise and changes in mental status. Other features include disseminated intravascular coagulation, hepatic and renal impairment. Metabolic disturbances had been reported. Death can result immediately due to pulmonary edema or delayed due to cardiotoxicity. Patients must be admitted to hospital and observed for at least 3 days. Symptomatic and supportive care is the mainstay of therapy. Zinc phosphide poisoning requires gastric lavage with excessive sodium bicarbonate solution. Tranexamic acid – an antifibrinolytic agent – was found to be of help in some cases. Psychosocial counseling in cases of intentional poisoning is an important aspect of overall management of the

  14. 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

  15. 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)

  16. Quantum dot infrared photodetectors based on indium phosphide

    International Nuclear Information System (INIS)

    Gebhard, T.

    2011-01-01

    The subject of this work is a systematic study of quantum dot infrared photodetectors based on indium-phosphide substrate by means of various spectroscopic and electronic measurement methods in order to understand the physical and technological processes. This enables a concise definition of strategies in order to realize next generation devices in this material system and to gain overall progress in the research field of quantum dot infrared photodetectors. The interpretation of the experimental results is supported by analytical and numerical simulations. The samples, grown by collaboration partners, were characterized using differential transmission and fast Fourier transform infrared spectroscopy, with a special emphasis on the latter one. Therefore, samples both in wedged waveguide geometry and samples with gold coated mesa structures have been processed. A large part of the discussion is dedicated to the current voltage characteristic of the devices, due to its large importance for device optimization, i.e. the reduction of the dark current plays a crucial role in the research field of high temperature infrared photon-detection. Further, results of photoluminescence measurements, performed by collaboration partners, have been used in order to attain a more complete picture of the samples' electronic band structure and in order to obtain complementary information with respect to other measurement methods applied within the experimental work and the simulation of the structures. In agreement to the simulations, a photocurrent response was observed at 6 and at 12 μm up to a temperature of 80 K, depending on the samples' design. The principle of parameter scaling was applied to the samples, in order to assign physical effects either to details in the samples' design or to technological quality aspects, i.e. the doping level and the thickness of the capping layer was varied. In addition to that a quantum well was introduced within a series of samples in order to

  17. A Plasma-Assisted Route to the Rapid Preparation of Transition-Metal Phosphides for Energy Conversion and Storage

    KAUST Repository

    Liang, Hanfeng; Alshareef, Husam N.

    2017-01-01

    with the method of preparation as the electronic, catalytic, and magnetic properties of the metal phosphides strongly depend on their synthesis routes. Commonly practiced processes such as solid-state synthesis and ball milling have proven to be reliable routes

  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. 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.)

  20. 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

  1. 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....

  2. 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

  3. Scaling-resistance of ruthenium- and ruthenium phosphides powders in argon and air

    International Nuclear Information System (INIS)

    Chernogorebko, V.B.; Semenov-Kobzar', A.A.; Kulik, L.Ya.

    1976-01-01

    The thermal stability of ruthenium phosphides in air diminishes as the content of phosphorus in the compound increases. The temperatures at which active oxidation of the powders starts are as follows: Ru-600, Ru 2 P-590, RuP-390, and RuP 2 -270 0 C. The oxidation of phosphorus in the phosphides proceeds in steps. The atoms of phosphorus which are most accessible to oxygen are first oxidated. Phosphorus atoms in the octahedral spaces are oxidated less easily, simultaneously with the oxidation of the ruthenium atoms. When heated in argon, Ru 2 P and RuP fuse congruently at 1,500 and 1,555 0 C respectively, while RuP 2 dissociates at 950 0 C. (author)

  4. Compton scattering studies of the electron momentum distribution in indium phosphide

    CERN Document Server

    Deb, A; Guin, R; Chatterjee, A K

    1999-01-01

    The electron momentum anisotropy of indium phosphide has been studied by measuring the directional Compton profiles of indium phosphide single crystals with the use of radiation from an sup 2 sup 4 sup 1 Am gamma source. Three different samples, cut along the [100], [110] and [111] planes, were used. The experimental anisotropy has been compared with the results based on the linear combination of Gaussian orbitals (LCGO) method. The agreement is very good with our theoretical results. It is found that the extrema appearing in the dependences on q of the anisotropies have an intimate connection with the bonding properties of the semiconductor. A self-consistent, all-electron, local density calculation for the partial density of states, total density of states and the charge analysis is also presented here.

  5. Synthesis of uniform-sized bimetallic iron-nickel phosphide nanorods

    International Nuclear Information System (INIS)

    Yoon, Ki Youl; Jang, Youngjin; Park, Jongnam; Hwang, Yosun; Koo, Bonil; Park, Je-Geun; Hyeon, Taeghwan

    2008-01-01

    We synthesized uniform-sized nanorods of iron-nickel phosphides from the thermal decomposition of metal-phosphine complexes. Uniform-sized (Fe x Ni 1-x ) 2 P nanorods (0≤x≤1) of various compositions were synthesized by thermal decomposition of Ni-trioctylphosphine (TOP) complex and Fe-TOP complex. By measuring magnetic properties, we found that blocking temperature and coercive field depend on Ni content in the nanorods. Both parameters were more sensitive to doping compared with bulk samples. - Graphical abstract: We synthesized uniform-sized nanorods of iron-nickel phosphides from thermal decomposition of metal-phosphine complexes. The magnetic studies showed that blocking temperature and coercive field depend on Ni content in the nanorods

  6. Neutron powder diffraction studies of Hydrogen and Denterium in Palladium Phosphides

    International Nuclear Information System (INIS)

    Andersson, Y.

    1986-01-01

    The use of the Rietveld-type profile refinements on neutron powder diffraction intensity data for determining crystallographic positions of hydrogen and deuterium in metal hydrides is illustrated by results obtained on some hydrogenated and deuterated palladium phosphides. The structural features of the solid solutions of hydrogen and deuterium in Pd/sb15/P/sb2/ Pd/sb6/P and Pd/sb3/P/sb1-u/ (0< u<0.28) are briefly presented and discussed

  7. Properties of epitaxial films of indium phosphides alloyed with erbium in strong electric fields

    International Nuclear Information System (INIS)

    Borisov, V.I.; Dvoryankin, V.F.; Korobkin, V.A.; Kudryashov, A.A.; Lopatin, V.V.; Lyubchenko, V.E.; Telegin, A.A.

    1986-01-01

    Temperature dependences of specific resistance and free charge-carrier mobility at low temperatures for indium phosphide films grown by liquid-phase epitaxial method with erbium additions (0.01-0.1 mass%). The main mechanisms of scattering for different temperature regions: scattering on ionized impurities in the rage from 20 to 40 K and lattice scattering at the temperature above 90 K are determined. The current density dependences on applied electric field strength are presented

  8. Acetaminophen and zinc phosphide for lethal management of invasive lizards Ctenosaura similis

    Directory of Open Access Journals (Sweden)

    Michael L. AVERY, John D. EISEMANN, Kandy L. KEACHER,Peter J. SAVARIE

    2011-10-01

    Full Text Available Reducing populations of invasive lizards through trapping and shooting is feasible in many cases but effective integrated management relies on a variety of tools, including toxicants. In Florida, using wild-caught non-native black spiny-tailed iguanas Ctenosaura similis, we screened acetaminophen and zinc phosphide to determine their suitability for effective population management of this prolific invasive species. Of the animals that received acetaminophen, none died except at the highest test dose, 240 mg per lizard, which is not practical for field use. Zinc phosphide produced 100% mortality at dose levels as little as 25 mg per lizard, equivalent to about 0.5% in bait which is lower than currently used in commercial baits for commensal rodent control. We conclude that zinc phosphide has potential as a useful tool for reducing populations of invasive lizards such as the black spiny-tailed iguana provided target-selective delivery methods are developed [Current Zoology 57 (5: 625–629, 2011].

  9. Ingestion of gallium phosphide nanowires has no adverse effect on Drosophila tissue function

    International Nuclear Information System (INIS)

    Adolfsson, Karl; Hammarin, Greger; Prinz, Christelle N; Schneider, Martina; Häcker, Udo

    2013-01-01

    Engineered nanoparticles have been under increasing scrutiny in recent years. High aspect ratio nanoparticles such as carbon nanotubes and nanowires have raised safety concerns due to their geometrical similarity to asbestos fibers. III–V epitaxial semiconductor nanowires are expected to be utilized in devices such as LEDs and solar cells and will thus be available to the public. In addition, clean-room staff fabricating and characterizing the nanowires are at risk of exposure, emphasizing the importance of investigating their possible toxicity. Here we investigated the effects of gallium phosphide nanowires on the fruit fly Drosophila melanogaster. Drosophila larvae and/or adults were exposed to gallium phosphide nanowires by ingestion with food. The toxicity and tissue interaction of the nanowires was evaluated by investigating tissue distribution, activation of immune response, genome-wide gene expression, life span, fecundity and somatic mutation rates. Our results show that gallium phosphide nanowires applied through the diet are not taken up into Drosophila tissues, do not elicit a measurable immune response or changes in genome-wide gene expression and do not significantly affect life span or somatic mutation rate. (paper)

  10. Plain abdominal radiography: A powerful tool to prognosticate outcome in patients with zinc phosphide poisoning

    International Nuclear Information System (INIS)

    Hassanian-Moghaddam, H.; Shahnazi, Makhtoom; Zamani, N.; Rahimi, M.; Bahrami-Motlagh, H.; Amiri, H.

    2014-01-01

    Aim: To evaluate the clinical features of zinc phosphide poisoning and to investigate whether outcome could be prognosticated based on abdominal radiography on presentation. Materials and methods: All zinc phosphide-poisoned patients who were referred to Loghman-Hakim Hospital between March 2011 and September 2013 were retrospectively reviewed. Data regarding patients' demographic characteristics, characteristics of the poisoning, abdominal radiography results, and patients' outcome were recorded. Results: In 102 patients, the most common presenting signs/symptoms were nausea and vomiting (60%). Four patients died and another seven had developed complications during their hospitalization (metabolic acidosis, liver abnormalities, or acute renal failure). Nineteen patients had radio-opaque abdominal radiographs, nine of whom had died or developed complications (p = 0.001). Plain abdominal radiography had a sensitivity and specificity of 81% and 89% in predicting the patients' death or further development of complications. The positive and negative predictive values were 47% and 97%, respectively. Conclusion: Plain abdominal radiography is a very good tool for prognostication in patients with zinc phosphide poisoning. Immediate abdominal radiography can help stratify patients into high- or low-risk groups and determine treatment strategies. - Highlights: • ZP poisoning may cause severe symptoms or death although less frequent compared to ALP. • ZP-poisoned patients may deteriorate within the first 72 hours post-ingestion. • Abdominal radiography is a good tool to predict death/complications in these patients

  11. Electrocatalytic activity of cobalt phosphide-modified graphite felt toward VO2+/VO2+ redox reaction

    Science.gov (United States)

    Ge, Zhijun; Wang, Ling; He, Zhangxing; Li, Yuehua; Jiang, Yingqiao; Meng, Wei; Dai, Lei

    2018-04-01

    A novel strategy for improving the electro-catalytic properties of graphite felt (GF) electrode in vanadium redox flow battery (VRFB) is designed by depositing cobalt phosphide (CoP) onto GF surface. The CoP powder is synthesized by direct carbonization of Co-based zeolitic imidazolate framework (ZIF-67) followed by phosphidation. Cyclic voltammetry results confirm that the CoP-modified graphite felt (GF-CoP) electrode has excellent reversibility and electro-catalytic activity to the VO2+/VO2+ cathodic reaction compared with the pristine GF electrode. The cell using GF-CoP electrode shows apparently higher discharge capacity over that based on GF electrode. The cell using GF-CoP electrode has the capacity of 67.2 mA h at 100 mA cm-2, 32.7 mA h larger than that using GF electrode. Compared with cell using GF electrode, the voltage efficiency of the cell based on GF-CoP electrode increases by 5.9% and energy efficiency by 5.4% at a current density of 100 mA cm-2. The cell using GF-CoP electrode can reach 94.31% capacity retention after 50 cycles at a current density of 30 mA cm-2. The results show that the CoP can effectively promote the VO2+/VO2+ redox reaction, implying that metal phosphides are a new kind of potential catalytic materials for VRFB.

  12. Orientation of Zn3P2 films via phosphidation of Zn precursors

    Science.gov (United States)

    Katsube, Ryoji; Nose, Yoshitaro

    2017-02-01

    Orientation of solar absorber is an important factor to achieve high efficiency of thin film solar cells. In the case of Zn3P2 which is a promising absorber of low-cost and high-efficiency solar cells, (110)/(001) orientation was only reported in previous studies. We have successfully prepared (101)-oriented Zn3P2 films by phosphidation of (0001)-oriented Zn films at 350 °C. The phosphidation mechanism of Zn is discussed through STEM observations on the partially-reacted sample and the consideration of the relationship between the crystal structures of Zn and Zn3P2 . We revealed that (0001)-oriented Zn led to nucleation of (101)-oriented Zn3P2 due to the similarity in atomic arrangement between Zn and Zn3P2 . The electrical resistivity of the (101)-oriented Zn3P2 film was lower than those of (110)/(001)-oriented films, which is an advantage of the phosphidation technique to the growth processes in previous works. The results in this study demonstrated that well-conductive Zn3P2 films could be obtained by controlling orientations of crystal grains, and provide a guiding principle for microstructure control in absorber materials.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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)

  18. 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

  19. 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.

  20. 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.

  1. 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)

  2. Engineering absorption and blackbody radiation in the far-infrared with surface phonon polaritons on gallium phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Streyer, W.; Law, S.; Rosenberg, A.; Wasserman, D. [Department of Electrical and Computer Engineering, University of Illinois Urbana Champaign, Urbana, Illinois 61801 (United States); Roberts, C.; Podolskiy, V. A. [Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States); Hoffman, A. J. [Department of Electrical Engineering, University of Notre Dame, South Bend, Indiana 46556 (United States)

    2014-03-31

    We demonstrate excitation of surface phonon polaritons on patterned gallium phosphide surfaces. Control over the light-polariton coupling frequencies is demonstrated by changing the pattern periodicity and used to experimentally determine the gallium phosphide surface phonon polariton dispersion curve. Selective emission via out-coupling of thermally excited surface phonon polaritons is experimentally demonstrated. Samples are characterized experimentally by Fourier transform infrared reflection and emission spectroscopy, and modeled using finite element techniques and rigorous coupled wave analysis. The use of phonon resonances for control of emissivity and excitation of bound surface waves offers a potential tool for the exploration of long-wavelength Reststrahlen band frequencies.

  3. Essential elucidation for preparation of supported nickel phosphide upon nickel phosphate precursor

    International Nuclear Information System (INIS)

    Liu, Xuguang; Xu, Lei; Zhang, Baoquan

    2014-01-01

    Preparation of supported nickel phosphide (Ni 2 P) depends on nickel phosphate precursor, generally related to its chemical composition and supports. Study of this dependence is essential and meaningful for the preparation of supported Ni 2 P with excellent catalytic activity. The chemical nature of nickel phosphate precursor is revealed by Raman and UV–vis spectra. It is found that initial P/Ni mole ratio ≥0.8 prohibits the Ni-O-Ni bridge bonding (i.e., nickel oxide). This chemical bonding will not result in Ni 2 P structure, verified by XRD characterization results. The alumina (namely, γ-Al 2 O 3 , θ-Al 2 O 3 , or α-Al 2 O 3 ) with distinct physiochemical properties also results in diverse chemical nature of nickel phosphate, and then different nickel phosphides. The influence of alumina support on producing Ni 2 P was explained by the theory of surface energy heterogeneity, calculated by the NLDFT method based on N 2 -sorption isotherm. The uniform surface energy of α-Al 2 O 3 results only in the nickel phosphosate precursor and thus the Ni 2 P phase. - Graphical abstract: Surface energy heterogeneity in alumina (namely α-Al 2 O 3 , θ-Al 2 O 3 , and γ-Al 2 O 3 ) supported multi-oxidic precursors with different reducibilities and thus diverse nickel phosphides (i.e., Ni 3 P, Ni 12 P 5 , Ni 2 P). - Highlights: • Preparing pure Ni 2 P. • Elucidating nickel phosphate precursor. • Associating with surface energy

  4. Efficient telecom to visible wavelength conversion in doubly resonant gallium phosphide microdisks

    Science.gov (United States)

    Lake, David P.; Mitchell, Matthew; Jayakumar, Harishankar; dos Santos, Laís Fujii; Curic, Davor; Barclay, Paul E.

    2016-01-01

    Resonant second harmonic generation between 1550 nm and 775 nm with normalized outside efficiency > 3.8 × 10 - 4 mW - 1 is demonstrated in a gallium phosphide microdisk supporting high-Q modes at visible ( Q ˜ 10 4 ) and infrared ( Q ˜ 10 5 ) wavelengths. The double resonance condition is satisfied for a specific pump power through intracavity photothermal temperature tuning using ˜ 360 μ W of 1550 nm light input to a fiber taper and coupled to a microdisk resonance. Power dependent efficiency consistent with a simple model for thermal tuning of the double resonance condition is observed.

  5. 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.

  6. HDO of Methyl Palmitate over Silica-Supported Ni Phosphides: Insight into Ni/P Effect

    Directory of Open Access Journals (Sweden)

    Irina V. Deliy

    2017-10-01

    Full Text Available Two sets of silica-supported nickel phosphide catalysts with a nickel content of about 2.5 and 10 wt % and Ni/P molar ratio 2/1, 1/1 and 1/2 in each set, were prepared by way of a temperature-programmed reduction method using (Ni(CH3COO2 and ((NH42HPO4 as a precursor. The NixPy/SiO2 catalysts were characterized using chemical analysis N2 physisorption, XRD, TEM, 31P MAS NMR. Methyl palmitate hydrodeoxygenation (HDO was performed in a trickle-bed reactor at 3 MPa and 290 °C with LHSV ranging from 0.3 to 16 h−1. The Ni/P ratio was found to affect the nickel phosphide phase composition, POx groups content and catalytic properties in methyl palmitate HDO with the TOF increased along with a decline of Ni/P ratio and a growth of POx groups’ content. Taking into account the possible routes of methyl palmitate conversion (metal-catalyzed hydrogenolysis or acid-catalyzed hydrolysis, we proposed that the enhancement of acid POx groups’ content with the Ni/P ratio decrease provides an enhancement of the rate of methyl palmitate conversion through the acceleration of acid-catalyzed hydrolysis.

  7. Three-dimensional interconnected nickel phosphide networks with hollow microstructures and desulfurization performance

    International Nuclear Information System (INIS)

    Zhang, Shuna; Zhang, Shujuan; Song, Limin; Wu, Xiaoqing; Fang, Sheng

    2014-01-01

    Graphical abstract: Three-dimensional interconnected nickel phosphide networks with hollow microstructures and desulfurization performance. - Highlights: • Three-dimensional Ni 2 P has been prepared using foam nickel as a template. • The microstructures interconnected and formed sponge-like porous networks. • Three-dimensional Ni 2 P shows superior hydrodesulfurization activity. - Abstract: Three-dimensional microstructured nickel phosphide (Ni 2 P) was fabricated by the reaction between foam nickel (Ni) and phosphorus red. The as-prepared Ni 2 P samples, as interconnected networks, maintained the original mesh structure of foamed nickel. The crystal structure and morphology of the as-synthesized Ni 2 P were characterized by X-ray diffraction, scanning electron microscopy, automatic mercury porosimetry and X-ray photoelectron spectroscopy. The SEM study showed adjacent hollow branches were mutually interconnected to form sponge-like networks. The investigation on pore structure provided detailed information for the hollow microstructures. The growth mechanism for the three-dimensionally structured Ni 2 P was postulated and discussed in detail. To investigate its catalytic properties, SiO 2 supported three-dimensional Ni 2 P was prepared successfully and evaluated for the hydrodesulfurization (HDS) of dibenzothiophene (DBT). DBT molecules were mostly hydrogenated and then desulfurized by Ni 2 P/SiO 2

  8. GXRD study of 100 MeV Fe9+ ion irradiated indium phosphide

    International Nuclear Information System (INIS)

    Dubey, R.L.; Dubey, S.K.; Kachhap, N.K.; Kanjilal, D.

    2014-01-01

    Swift heavy ions with MeV to GeV kinetic energy offer unique possibilities of modifying material properties. Each projectile passing through the target material causes loss of its energy by ion-electrons and ion-atoms interaction with the target material. The consequence of formal one is to change in surface properties and latter to produces damage deep in the target material near the projected range of projectile. In the present work, indium phosphide samples were irradiated at 100 MeV 56 Fe 9+ ions with different fluences varying from 1x10 12 to 1x10 14 ions cm -2 using the 15UD Pelletron facilities at Inter University Accelerator Centre (IUAC), New Delhi. Grazing angle X-ray diffraction technique was used to investigate the structural properties of irradiated indium phosphide at different depths. The GXRD spectra of non-irradiated and irradiated samples were recorded at different grazing angle i.e 1°, 2°, 3°, 4° and 5° to get the structural information over the projected range. The detailed result will be presented and discussed in the conference. (author)

  9. Moringa oleifera extract (Lam) attenuates Aluminium phosphide-induced acute cardiac toxicity in rats.

    Science.gov (United States)

    Gouda, Ahmed S; El-Nabarawy, Nagla A; Ibrahim, Samah F

    2018-01-01

    Moringa oleifera extract (Lam) has many antioxidant and protective properties. Objective: to investigate the antioxidant activities of Lam in counteracting the high oxidative stress caused by acute sub-lethal aluminium phosphide (AlP) intoxication in rat heart. These activities will be detected by histopathological examination and some oxidative stress biomarkers. a single sub-lethal dose of Alp (2 mg/kg body weight) was administered orally, and Lam was given orally at a dose (100 mg/kg body weight) one hour after receiving AlP to rats. aluminium phosphide caused significant cardiac histopathological changes with a significant increase in malondialdehyde (MDA); lipid peroxidation marker; and a significant depletion of antioxidant enzymes (catalase and glutathione reductase). However, treatment with Lam protected efficiently the cardiac tissue of intoxicated rats by increasing antioxidants levels with slight decreasing in MDA production compared to untreated group. This study suggested that Moringa oleifera extract could possibly restore the altered cardiac histopathology and some antioxidant power in AlP intoxicated rats, and it could even be used as adjuvant therapy against AlP-induced cardiotoxicity.

  10. Proceedings of the first international conference on indium phosphide and related materials for advanced electronic and optical devices

    International Nuclear Information System (INIS)

    Singh, R.; Messick, L.J.

    1989-01-01

    This book contains the proceedings of the first international conference on indium phosphide and related materials for advanced electronic and optical devices. Topics covered include: Growth and characterization of bulk and epitaxial films, Passivation technology, Processing technology, High speed optoelectronic integrated circuits, and Solar cells

  11. 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

  12. 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.)

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. Instability of Yb3+ and Pr3+ low-symmetry luminescence centers in gallium phosphide

    International Nuclear Information System (INIS)

    Kasatkin, V.A.

    1985-01-01

    The stability of γb 3+ and Pr 3+ low-symmetry luminescence centers formed in gallium phosphide during quenching were studied in the process of durable storage and annealing. Observation of the Yb 3+ and Pr 3+ centrer states was accomplished by the photoluminescence spectra at 18 K. It has been established that annealing in the dark under normal conditions results in a reduced integral luminescence intensity of all low-symmetry Yb 3+ and Pr 3+ centers. Annealing of quenched GaP and GaP saples at 400 K results in complete disappearance of intracenter luminescence of Pr 3+ and low-symmetry Yb 3+ centers. Decomposition during storage and low anealing temperature point to the instability of low-symmetry centers of Pr 3+ and Yb 3+ luminescence

  1. Treatment of Aluminium Phosphide Poisoning with a Combination of Intravenous Glucagon, Digoxin and Antioxidant Agents

    Directory of Open Access Journals (Sweden)

    Zohreh Oghabian

    2016-08-01

    Full Text Available Aluminium phosphide (AlP is used to protect stored grains from rodents. It produces phosphine gas (PH3, a mitochondrial poison thought to cause toxicity by blocking the cytochrome c oxidase enzyme and inhibiting oxidative phosphorylation, which results in cell death. AlP poisoning has a high mortality rate among humans due to the rapid onset of cardiogenic shock and metabolic acidosis, despite aggressive treatment. We report a 21-yearold male who was referred to the Afzalipour Hospital, Kerman, Iran, in 2015 after having intentionally ingested a 3 g AlP tablet. He was successfully treated with crystalloid fluids, vasopressors, sodium bicarbonate, digoxin, glucagon and antioxidant agents and was discharged from the hospital six days after admission in good clinical condition. For the treatment of AlP poisoning, the combination of glucagon and digoxin with antioxidant agents should be considered. However, evaluation of further cases is necessary to optimise treatment protocols.

  2. Transition Metal Phosphide Nanoparticles Supported on SBA-15 as Highly Selective Hydrodeoxygenation Catalysts for the Production of Advanced Biofuels.

    Science.gov (United States)

    Yang, Yongxing; Ochoa-Hernández, Cristina; de la Peña O'Shea, Víctor A; Pizarro, Patricia; Coronado, Juan M; Serrano, David P

    2015-09-01

    A series of catalysts constituted by nanoparticles of transition metal (M = Fe, Co, Ni and Mo) phosphides (TMP) dispersed on SBA-15 were synthesized by reduction of the corresponding metal phosphate precursors previously impregnated on the mesostructured support. All the samples contained a metal-loading of 20 wt% and with an initial M/P mole ratio of 1, and they were characterized by X-ray diffraction (XRD), N2 sorption, H2-TPR and transmission electron microscopy (TEM). Metal phosphide nanocatalysts were tested in a high pressure continuous flow reactor for the hydrodeoxygenation (HDO) of a methyl ester blend containing methyl oleate (C17H33-COO-CH3) as main component (70%). This mixture constitutes a convenient surrogate of triglycerides present in vegetable oils, and following catalytic hydrotreating yields mainly n-alkanes. The results of the catalytic assays indicate that Ni2P/SBA-15 catalyst presents the highest ester conversion, whereas the transformation rate is about 20% lower for MoP/SBA-15. In contrast, catalysts based on Fe and Co phosphides show a rather limited activity. Hydrocarbon distribution in the liquid product suggests that both hydrodeoxygenation and decarboxylation/decarbonylation reactions occur simultaneously over the different catalysts, although MoP/SBA-15 possess a selectivity towards hydrodeoxygenation exceeding 90%. Accordingly, the catalyst based on MoP affords the highest yield of n-octadecane, which is the preferred product in terms of carbon atom economy. Subsequently, in order to conjugate the advantages of both Ni and Mo phosphides, a series of catalysts containing variable proportions of both metals were prepared. The obtained results reveal that the mixed phosphides catalysts present a catalytic behavior intermediate between those of the monometallic phosphides. Accordingly, only marginal enhancement of the yield of n-octadecane is obtained for the catalysts with a Mo/Ni ratio of 3. Nevertheless, owing to this high selectivity

  3. Process Development of Gallium Nitride Phosphide Core-Shell Nanowire Array Solar Cell

    Science.gov (United States)

    Chuang, Chen

    Dilute Nitride GaNP is a promising materials for opto-electronic applications due to its band gap tunability. The efficiency of GaNxP1-x /GaNyP1-y core-shell nanowire solar cell (NWSC) is expected to reach as high as 44% by 1% N and 9% N in the core and shell, respectively. By developing such high efficiency NWSCs on silicon substrate, a further reduction of the cost of solar photovoltaic can be further reduced to 61$/MWh, which is competitive to levelized cost of electricity (LCOE) of fossil fuels. Therefore, a suitable NWSC structure and fabrication process need to be developed to achieve this promising NWSC. This thesis is devoted to the study on the development of fabrication process of GaNxP 1-x/GaNyP1-y core-shell Nanowire solar cell. The thesis is divided into two major parts. In the first parts, previously grown GaP/GaNyP1-y core-shell nanowire samples are used to develop the fabrication process of Gallium Nitride Phosphide nanowire solar cell. The design for nanowire arrays, passivation layer, polymeric filler spacer, transparent col- lecting layer and metal contact are discussed and fabricated. The property of these NWSCs are also characterized to point out the future development of Gal- lium Nitride Phosphide NWSC. In the second part, a nano-hole template made by nanosphere lithography is studied for selective area growth of nanowires to improve the structure of core-shell NWSC. The fabrication process of nano-hole templates and the results are presented. To have a consistent features of nano-hole tem- plate, the Taguchi Method is used to optimize the fabrication process of nano-hole templates.

  4. Preparation and electrical properties of boron and boron phosphide films obtained by gas source molecular beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kumashiro, Y.; Yokoyama, T.; Sakamoto, T.; Fujita, T. [Yokohama National Univ. (Japan)

    1997-10-01

    Boron and boron phosphide films were prepared by gas source molecular beam deposition on sapphire crystal at various substrate temperatures up to 800{degrees}C using cracked B{sub 2}H{sub 6} (2% in H{sub 2}) at 300{degrees}C and cracked PH{sub 3} (20% in H{sub 2}) at 900{degrees}C. The substrate temperatures and gas flow rates of the reactant gases determined the film growth. The boron films with amorphous structure are p type. Increasing growth times lead to increasing mobilities and decreasing carrier concentrations. Boron phosphide film with maximum P/B ratio is obtained at a substrate temperature of 600{degrees}C, below and above which they become phosphorous deficient due to insufficient supply of phosphorus and thermal desorption of the phosphorus as P{sub 2}, respectively, but they are all n type conductors due to phosphorus vacancies.

  5. 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

  6. A Plasma-Assisted Route to the Rapid Preparation of Transition-Metal Phosphides for Energy Conversion and Storage

    KAUST Repository

    Liang, Hanfeng

    2017-06-06

    Transition-metal phosphides (TMPs) are important materials that have been widely used in catalysis, supercapacitors, batteries, sensors, light-emitting diodes, and magnets. The physical and chemical structure of a metal phosphide varies with the method of preparation as the electronic, catalytic, and magnetic properties of the metal phosphides strongly depend on their synthesis routes. Commonly practiced processes such as solid-state synthesis and ball milling have proven to be reliable routes to prepare TMPs but they generally require high temperature and long reaction time. Here, a recently developed plasma-assisted conversion route for the preparation of TMPs is reviewed, along with their applications in energy conversion and storage, including water oxidation electrocatalysis, sodium-ion batteries, and supercapacitors. The plasma-assisted synthetic route should open up a new avenue to prepare TMPs with tailored structure and morphology for various applications. In fact, the process may be further extended to the synthesis of a wide range of transition-metal compounds such as borides and fluorides at low temperature and in a rapid manner.

  7. Ensembles of indium phosphide nanowires: physical properties and functional devices integrated on non-single crystal platforms

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Nobuhiko P.; Lohn, Andrew; Onishi, Takehiro [University of California, Santa Cruz (United States). Baskin School of Engineering; NASA Ames Research Center, Nanostructured Energy Conversion Technology and Research (NECTAR), Advanced Studies Laboratories, Univ. of California Santa Cruz, Moffett Field, CA (United States); Mathai, Sagi; Li, Xuema; Straznicky, Joseph; Wang, Shih-Yuan; Williams, R.S. [Hewlett-Packard Laboratories, Information and Quantum Systems Laboratory, Palo Alto, CA (United States); Logeeswaran, V.J.; Islam, M.S. [University of California Davis, Electrical and Computer Engineering, Davis, CA (United States)

    2009-06-15

    A new route to grow an ensemble of indium phosphide single-crystal semiconductor nanowires is described. Unlike conventional epitaxial growth of single-crystal semiconductor films, the proposed route for growing semiconductor nanowires does not require a single-crystal semiconductor substrate. In the proposed route, instead of using single-crystal semiconductor substrates that are characterized by their long-range atomic ordering, a template layer that possesses short-range atomic ordering prepared on a non-single-crystal substrate is employed. On the template layer, epitaxial information associated with its short-range atomic ordering is available within an area that is comparable to that of a nanowire root. Thus the template layer locally provides epitaxial information required for the growth of semiconductor nanowires. In the particular demonstration described in this paper, hydrogenated silicon was used as a template layer for epitaxial growth of indium phosphide nanowires. The indium phosphide nanowires grown on the hydrogenerated silicon template layer were found to be single crystal and optically active. Simple photoconductors and pin-diodes were fabricated and tested with the view towards various optoelectronic device applications where group III-V compound semiconductors are functionally integrated onto non-single-crystal platforms. (orig.)

  8. Ensembles of indium phosphide nanowires: physical properties and functional devices integrated on non-single crystal platforms

    International Nuclear Information System (INIS)

    Kobayashi, Nobuhiko P.; Lohn, Andrew; Onishi, Takehiro; Mathai, Sagi; Li, Xuema; Straznicky, Joseph; Wang, Shih-Yuan; Williams, R.S.; Logeeswaran, V.J.; Islam, M.S.

    2009-01-01

    A new route to grow an ensemble of indium phosphide single-crystal semiconductor nanowires is described. Unlike conventional epitaxial growth of single-crystal semiconductor films, the proposed route for growing semiconductor nanowires does not require a single-crystal semiconductor substrate. In the proposed route, instead of using single-crystal semiconductor substrates that are characterized by their long-range atomic ordering, a template layer that possesses short-range atomic ordering prepared on a non-single-crystal substrate is employed. On the template layer, epitaxial information associated with its short-range atomic ordering is available within an area that is comparable to that of a nanowire root. Thus the template layer locally provides epitaxial information required for the growth of semiconductor nanowires. In the particular demonstration described in this paper, hydrogenated silicon was used as a template layer for epitaxial growth of indium phosphide nanowires. The indium phosphide nanowires grown on the hydrogenerated silicon template layer were found to be single crystal and optically active. Simple photoconductors and pin-diodes were fabricated and tested with the view towards various optoelectronic device applications where group III-V compound semiconductors are functionally integrated onto non-single-crystal platforms. (orig.)

  9. Rodenticide Comparative Effect of Klerat® and Zinc Phosphide for Controlling Zoonotic Cutaneous Leishmaniasis in Central Iran

    Directory of Open Access Journals (Sweden)

    Arshad VEYSI

    2016-12-01

    Full Text Available Background: Zoonotic cutaneous leishmaniasis (ZCL is a neglected disease with public health importance that is common in many rural areas of Iran. In recent years, behavioral resistance and/or bait shyness against the common rodenticide among reservoir hosts of ZCL have been reported. The aim of this study was to evaluate the effectiveness of Klerat® and zinc phosphide against natural reservoir of ZCL.Methods: This survey was carried out in four villages located 45 to 95 km far from Esfahan City Esfahan province, central Iran from April to November 2011. The rodent burrows were counted destroyed and reopened holes baited around all villages. Effect of rodent control operation on the main vector density and incidence of ZCL were evaluated.Results: The reduction rate of rodent burrows after intervention calculated to be at 62.8% in Klerat® and 58.15% in zinc phosphide treated areas. Statistical analysis showed no difference between the densities of the vector in indoors and outdoors in intervention and control areas. The incidence of the disease between treated and control areas after intervention was statistically different (P< 0.05.Conclusion: Klerat® could be a suitable alternative for zinc phosphide in a specific condition such as behavior resistance or occurrence of bait shyness.

  10. Ellipsometric analysis and optical absorption characterization of gallium phosphide nanoparticulate thin film

    International Nuclear Information System (INIS)

    Zhang Qi-Xian; Ruan Fang-Ping; Wei Wen-Sheng

    2011-01-01

    Gallium phosphide (GaP) nanoparticulate thin films were easily fabricated by colloidal suspension deposition via GaP nanoparticles dispersed in N,N-dimethylformamide. The microstructure of the film was performed by x-ray diffraction, high resolution transmission electron microscopy and field emission scanning electron microscopy. The film was further investigated by spectroscopic ellipsometry. After the model GaP+void|SiO 2 was built and an effective medium approximation was adopted, the values of the refractive index n and the extinction coefficient k were calculated for the energy range of 0.75 eV–4.0 eV using the dispersion formula in DeltaPsi2 software. The absorption coefficient of the film was calculated from its k and its energy gaps were further estimated according to the Tauc equation, which were further verified by its fluorescence spectrum measurement. The structure and optical absorption properties of the nanoparticulate films are promising for their potential applications in hybrid solar cells. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  11. Ellipsometric analysis and optical absorption characterization of gallium phosphide nanoparticulate thin film

    Science.gov (United States)

    Zhang, Qi-Xian; Wei, Wen-Sheng; Ruan, Fang-Ping

    2011-04-01

    Gallium phosphide (GaP) nanoparticulate thin films were easily fabricated by colloidal suspension deposition via GaP nanoparticles dispersed in N,N-dimethylformamide. The microstructure of the film was performed by x-ray diffraction, high resolution transmission electron microscopy and field emission scanning electron microscopy. The film was further investigated by spectroscopic ellipsometry. After the model GaP+void|SiO2 was built and an effective medium approximation was adopted, the values of the refractive index n and the extinction coefficient k were calculated for the energy range of 0.75 eV-4.0 eV using the dispersion formula in DeltaPsi2 software. The absorption coefficient of the film was calculated from its k and its energy gaps were further estimated according to the Tauc equation, which were further verified by its fluorescence spectrum measurement. The structure and optical absorption properties of the nanoparticulate films are promising for their potential applications in hybrid solar cells.

  12. Heterogeneous Bimetallic Phosphide/Sulfide Nanocomposite for Efficient Solar-Energy-Driven Overall Water Splitting.

    Science.gov (United States)

    Xin, Yanmei; Kan, Xiang; Gan, Li-Yong; Zhang, Zhonghai

    2017-10-24

    Solar-driven overall water splitting is highly desirable for hydrogen generation with sustainable energy sources, which need efficient, earth-abundant, robust, and bifunctional electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, we propose a heterogeneous bimetallic phosphide/sulfide nanocomposite electrocatalyst of NiFeSP on nickel foam (NiFeSP/NF), which shows superior electrocatalytic activity of low overpotentials of 91 mV at -10 mA cm -2 for HER and of 240 mV at 50 mA cm -2 for OER in 1 M KOH solution. In addition, the NiFeSP/NF presents excellent overall water splitting performance with a cell voltage as low as 1.58 V at a current density of 10 mA cm -2 . Combining with a photovoltaic device of a Si solar cell or integrating into photoelectrochemical (PEC) systems, the bifunctional NiFeSP/NF electrocatalyst implements unassisted solar-driven water splitting with a solar-to-hydrogen conversion efficiency of ∼9.2% and significantly enhanced PEC performance, respectively.

  13. V{sub 18}P{sub 9}C{sub 2}. A complex phosphide carbide

    Energy Technology Data Exchange (ETDEWEB)

    Boller, Herbert [Linz Univ. (Austria). Inst. fuer Anorganische Chemie; Effenberger, Herta [Wien Univ. (Austria). Inst. fuer Mineralogie und Kristallographie

    2016-08-01

    V{sub 18}P{sub 9}C{sub 2} crystallizes in the orthorhombic space group Pmma with the lattice parameters a = 17.044(3), b = 3.2219(7), and c = 13.030(2) Aa, Z = 2. The crystal structure is composed of 19 symmetry-independent atoms. The crystal structure is considered as a network formed by the transition metal atoms exhibiting cubic, trigonal prismatic, and octahedral voids centered by V, P, and C atoms, respectively. Vice versa, the V and P atoms form a three-dimensional network. The two CV{sub 6} octahedra are edge- and corner-connected to chains running parallel to [010]. The five unique P atoms are trigonal prismatically coordinated by V atoms with one to three faces capped again by a V atom. The V atoms have mainly cubic environments formed solely by V or by V and P atoms. V{sub 18}P{sub 9}C{sub 2} exhibits some structural relations to other compounds of the ternary system V-P-C as well as to other intermetallic phases. Despite the low carbon content, V{sub 18}P{sub 9}C{sub 2} is considered as a ternary compound rather than an interstitially stabilized (binary) phosphide in view of its special structural features.

  14. Preparation and study of the properties of indium phosphide thin films impregnated with cadmium and zinc

    International Nuclear Information System (INIS)

    Moutinho, H.R.

    1984-01-01

    Indium phosphide thin films were deposited by vacuum evaporation of indium and phosphorous, using the three-temperature method. The effects of the introduction of cadmium and zinc, group II impurities, on the properties of these films were studied. The introduction of cadmium was achieved by coevaporation of this element during the film deposition. The introduction of zinc was done by diffusion of this element in intrinsic films. Analyses of these films were carried out by the study of the composition, morphology, structure, optical properties and electrical properties. The introduction of cadmium led to the reduction of grain size and increase in the bandgap and in certain cases, even change in morphology. Phases of CdP2 and β-CdP2 were detected and the resistivity increased by some orders of magnitude. The introduction of zinc did not change the morphology, crystalline structure and bandgap. However, a new energy level corresponding to the zinc acceptor level was found and the resistivity increased by some orders of magnitude. (Author) [pt

  15. Triamidoamine-uranium(IV)-stabilized terminal parent phosphide and phosphinidene complexes

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, Benedict M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [School of Chemistry, University of Nottingham (United Kingdom); Balazs, Gabor; Scheer, Manfred [Institut of Inorganic Chemistry, University of Regensburg (Germany); Tuna, Floriana; McInnes, Eric J.L. [School of Chemistry and Photon Science Institute, University of Manchester (United Kingdom)

    2014-04-22

    Reaction of [U(Tren{sup TIPS})(THF)][BPh{sub 4}] (1; Tren{sup TIPS}=N{CH_2CH_2NSi(iPr)_3}{sub 3}) with NaPH{sub 2} afforded the novel f-block terminal parent phosphide complex [U(Tren {sup TIPS})(PH{sub 2})] (2; U-P=2.883(2) Aa). Treatment of 2 with one equivalent of KCH{sub 2}C{sub 6}H{sub 5} and two equivalents of benzo-15-crown-5 ether (B15C5) afforded the unprecedented metal-stabilized terminal parent phosphinidene complex [U(Tren{sup TIPS})(PH)][K(B15C5){sub 2}] (4; U=P=2.613(2) Aa). DFT calculations reveal a polarized-covalent U=P bond with a Mayer bond order of 1.92. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Assembly of phosphide nanocrystals into porous networks: formation of InP gels and aerogels.

    Science.gov (United States)

    Hitihami-Mudiyanselage, Asha; Senevirathne, Keerthi; Brock, Stephanie L

    2013-02-26

    The applicability of sol-gel nanoparticle assembly routes, previously employed for metal chalcogenides, to phosphides is reported for the case of InP. Two different sizes (3.5 and 6.0 nm) of InP nanoparticles were synthesized by solution-phase arrested precipitation, capped with thiolate ligands, and oxidized with H₂O₂ or O₂/light to induce gel formation. The gels were aged, solvent-exchanged, and then supercritically dried to obtain aerogels with both meso- (2-50 nm) and macropores (>50 nm) and accessible surface areas of ∼200 m²/g. Aerogels showed higher band gap values relative to precursor nanoparticles, suggesting that during the process of assembling nanoparticles into 3D architectures, particle size reduction may have taken place. In contrast to metal chalcogenide gelation, InP gels did not form using tetranitromethane, a non-oxygen-transferring oxidant. The requirement of an oxygen-transferring oxidant, combined with X-ray photoelectron spectroscopy data showing oxidized phosphorus, suggests gelation is occurring due to condensation of phosphorus oxoanionic moieties generated at the interfaces. The ability to link discrete InP nanoparticles into a 3D porous network while maintaining quantum confinement is expected to facilitate exploitation of nanostructured InP in solid-state devices.

  17. Electrostatically driven resonance energy transfer in "cationic" biocompatible indium phosphide quantum dots.

    Science.gov (United States)

    Devatha, Gayathri; Roy, Soumendu; Rao, Anish; Mallick, Abhik; Basu, Sudipta; Pillai, Pramod P

    2017-05-01

    Indium Phosphide Quantum Dots (InP QDs) have emerged as an alternative to toxic metal ion based QDs in nanobiotechnology. The ability to generate cationic surface charge, without compromising stability and biocompatibility, is essential in realizing the full potential of InP QDs in biological applications. We have addressed this challenge by developing a place exchange protocol for the preparation of cationic InP/ZnS QDs. The quaternary ammonium group provides the much required permanent positive charge and stability to InP/ZnS QDs in biofluids. The two important properties of QDs, namely bioimaging and light induced resonance energy transfer, are successfully demonstrated in cationic InP/ZnS QDs. The low cytotoxicity and stable photoluminescence of cationic InP/ZnS QDs inside cells make them ideal candidates as optical probes for cellular imaging. An efficient resonance energy transfer ( E ∼ 60%) is observed, under physiological conditions, between the cationic InP/ZnS QD donor and anionic dye acceptor. A large bimolecular quenching constant along with a linear Stern-Volmer plot confirms the formation of a strong ground state complex between the cationic InP/ZnS QDs and the anionic dye. Control experiments prove the role of electrostatic attraction in driving the light induced interactions, which can rightfully form the basis for future nano-bio studies between cationic InP/ZnS QDs and anionic biomolecules.

  18. Photoluminescence blue shift of indium phosphide nanowire networks with aluminum oxide coating

    International Nuclear Information System (INIS)

    Fryauf, David M.; Zhang, Junce; Norris, Kate J.; Diaz Leon, Juan J.; Oye, Michael M.; Kobayashi, Nobuhiko P.; Wei, Min

    2014-01-01

    This paper describes our finding that optical properties of semiconductor nanowires were modified by depositing a thin layer of metal oxide. Indium phosphide nanowires were grown by metal organic chemical vapor deposition on silicon substrates with gold catalyst resulting in three-dimensional nanowire networks, and optical properties were obtained from the collective nanowire networks. The networks were coated with an aluminum oxide thin film deposited by plasma-enhanced atomic layer deposition. We studied the dependence of the peak wavelength of photoluminescence spectra on the thickness of the oxide coatings. A continuous blue shift in photoluminescence spectra was observed when the thickness of the oxide coating was increased. The observed blue shift is attributed to the Burstein-Moss effect due to increased carrier concentration in the nanowire cores caused by repulsion from intrinsic negative fixed charges located at the inner oxide surface. Samples were further characterized by scanning electron microscopy, Raman spectroscopy, transmission electron microscopy, and selective area diffractometry to better understand the physical mechanisms for the blue shift. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Photoluminescence blue shift of indium phosphide nanowire networks with aluminum oxide coating

    Energy Technology Data Exchange (ETDEWEB)

    Fryauf, David M.; Zhang, Junce; Norris, Kate J.; Diaz Leon, Juan J.; Oye, Michael M.; Kobayashi, Nobuhiko P. [Nanostructured Energy Conversion Technology and Research (NECTAR), Advanced Studies Laboratories, University of California, Santa Cruz, CA (United States); Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA (United States); NASA Ames Research Center, Moffett Field, CA (United States); Wei, Min [Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA (United States); School of Micro-Electronics and Solid-Electronics, University of Electronic Science and Technology of China, Chengdu (China)

    2014-07-15

    This paper describes our finding that optical properties of semiconductor nanowires were modified by depositing a thin layer of metal oxide. Indium phosphide nanowires were grown by metal organic chemical vapor deposition on silicon substrates with gold catalyst resulting in three-dimensional nanowire networks, and optical properties were obtained from the collective nanowire networks. The networks were coated with an aluminum oxide thin film deposited by plasma-enhanced atomic layer deposition. We studied the dependence of the peak wavelength of photoluminescence spectra on the thickness of the oxide coatings. A continuous blue shift in photoluminescence spectra was observed when the thickness of the oxide coating was increased. The observed blue shift is attributed to the Burstein-Moss effect due to increased carrier concentration in the nanowire cores caused by repulsion from intrinsic negative fixed charges located at the inner oxide surface. Samples were further characterized by scanning electron microscopy, Raman spectroscopy, transmission electron microscopy, and selective area diffractometry to better understand the physical mechanisms for the blue shift. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. High pressure study of the zinc phosphide semiconductor compound in two different phases

    International Nuclear Information System (INIS)

    Mokhtari, Ali

    2009-01-01

    Electronic and structural properties of the zinc phosphide semiconductor compound are calculated at hydrostatic pressure using the full-potential all-electron linearized augmented plane wave plus local orbital (FP-LAPW+lo) method in both cubic and tetragonal phases. The exchange-correlation potential is treated by the generalized gradient approximation within the scheme of Perdew, Burke and Ernzerhof, GGA96 (1996 Phys. Rev. Lett. 77 3865). Also, the Engel and Vosko GGA formalism, EV-GGA (Engel and Vosko 1993 Phys. Rev. B 47 13164), is used to improve the band-gap results. Internal parameters are optimized by relaxing the atomic positions in the force directions using the Hellman-Feynman approach. The lattice constants, internal parameters, bulk modulus, cohesive energy and band structures have been calculated and compared to the available experimental and theoretical results. The structural calculations predict that the stable phase is tetragonal. The effects of hydrostatic pressure on the behavior of band parameters such as band-gap, valence bandwidths and internal gaps (the energy gap between different parts of the valence bands) are studied using both GGA96 and EV-GGA.

  1. Density functional study of the group II phosphide semiconductor compounds under hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, Ali [Simulation Laboratory, Department of Physics, Faculty of Science, Shahrekord University, PB 115, Shahrekord (Iran, Islamic Republic of)], E-mail: mokhtari@sci.sku.ac.ir

    2008-04-02

    The full-potential all-electron linearized augmented plane wave plus local orbital (FP-LAPW+lo) method, as implemented in the suite of software WIEN2k, has been used to systematically investigate the structural and electronic properties of the group II phosphide semiconductor compounds M{sub 3}P{sub 2} (M = Be, Mg and Ca). The exchange-correlation functional was approximated as a generalized gradient functional introduced by Perdew-Burke-Ernzerhof (GGA96) and Engel-Vosko (EV-GGA). Internal parameters were optimized by relaxing the atomic positions in the force directions using the Hellman-Feynman approach. The structural parameters, bulk modules, cohesive energy, band structures and density of states have been calculated and compared to the available experimental and theoretical results. These compounds are predicted to be semiconductors with the direct band gap of about 1.60, 2.55 and 2.62 eV for Be{sub 3}P{sub 2}, Mg{sub 3}P{sub 2} and Ca{sub 3}P{sub 2}, respectively. The effects of hydrostatic pressure on the behavior of band parameters such as band gap, valence bandwidths and anti-symmetric gap (the energy gap between two parts of the valence bands) are investigated using both GGA96 and EV-GGA. The contribution of s, p and d orbitals of different atoms to the density of states is discussed in detail.

  2. Density functional study of the group II phosphide semiconductor compounds under hydrostatic pressure

    International Nuclear Information System (INIS)

    Mokhtari, Ali

    2008-01-01

    The full-potential all-electron linearized augmented plane wave plus local orbital (FP-LAPW+lo) method, as implemented in the suite of software WIEN2k, has been used to systematically investigate the structural and electronic properties of the group II phosphide semiconductor compounds M 3 P 2 (M = Be, Mg and Ca). The exchange-correlation functional was approximated as a generalized gradient functional introduced by Perdew-Burke-Ernzerhof (GGA96) and Engel-Vosko (EV-GGA). Internal parameters were optimized by relaxing the atomic positions in the force directions using the Hellman-Feynman approach. The structural parameters, bulk modules, cohesive energy, band structures and density of states have been calculated and compared to the available experimental and theoretical results. These compounds are predicted to be semiconductors with the direct band gap of about 1.60, 2.55 and 2.62 eV for Be 3 P 2 , Mg 3 P 2 and Ca 3 P 2 , respectively. The effects of hydrostatic pressure on the behavior of band parameters such as band gap, valence bandwidths and anti-symmetric gap (the energy gap between two parts of the valence bands) are investigated using both GGA96 and EV-GGA. The contribution of s, p and d orbitals of different atoms to the density of states is discussed in detail

  3. High pressure study of the zinc phosphide semiconductor compound in two different phases

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, Ali [Simulation Laboratory, Department of Physics, Faculty of Science, Shahrekord University, PB 115, Shahrekord (Iran, Islamic Republic of)], E-mail: mokhtari@sci.sku.ac.ir

    2009-07-08

    Electronic and structural properties of the zinc phosphide semiconductor compound are calculated at hydrostatic pressure using the full-potential all-electron linearized augmented plane wave plus local orbital (FP-LAPW+lo) method in both cubic and tetragonal phases. The exchange-correlation potential is treated by the generalized gradient approximation within the scheme of Perdew, Burke and Ernzerhof, GGA96 (1996 Phys. Rev. Lett. 77 3865). Also, the Engel and Vosko GGA formalism, EV-GGA (Engel and Vosko 1993 Phys. Rev. B 47 13164), is used to improve the band-gap results. Internal parameters are optimized by relaxing the atomic positions in the force directions using the Hellman-Feynman approach. The lattice constants, internal parameters, bulk modulus, cohesive energy and band structures have been calculated and compared to the available experimental and theoretical results. The structural calculations predict that the stable phase is tetragonal. The effects of hydrostatic pressure on the behavior of band parameters such as band-gap, valence bandwidths and internal gaps (the energy gap between different parts of the valence bands) are studied using both GGA96 and EV-GGA.

  4. Catalytic Activities of Noble Metal Phosphides for Hydrogenation and Hydrodesulfurization Reactions

    Directory of Open Access Journals (Sweden)

    Yasuharu Kanda

    2018-04-01

    Full Text Available In this work, the development of a highly active noble metal phosphide (NMXPY-based hydrodesulfurization (HDS catalyst with a high hydrogenating ability for heavy oils was studied. NMXPY catalysts were obtained by reduction of P-added noble metals (NM-P, NM: Rh, Pd, Ru supported on SiO2. The order of activities for the hydrogenation of biphenyl was Rh-P > NiMoS > Pd-P > Ru-P. This order was almost the same as that of the catalytic activities for the HDS of dibenzothiophene. In the HDS of 4,6-dimethyldibenzothiophene (4,6-DMDBT, the HDS activity of the Rh-P catalyst increased with increasing reaction temperature, but the maximum HDS activity for the NiMoS catalyst was observed at 270 °C. The Rh-P catalyst yielded fully hydrogenated products with high selectivity compared with the NiMoS catalyst. Furthermore, XRD analysis of the spent Rh-P catalysts revealed that the Rh2P phase possessed high sulfur tolerance and resistance to sintering.

  5. Observation of three-component fermions in the topological semimetal molybdenum phosphide

    Science.gov (United States)

    Lv, B. Q.; Feng, Z.-L.; Xu, Q.-N.; Gao, X.; Ma, J.-Z.; Kong, L.-Y.; Richard, P.; Huang, Y.-B.; Strocov, V. N.; Fang, C.; Weng, H.-M.; Shi, Y.-G.; Qian, T.; Ding, H.

    2017-06-01

    In quantum field theory, Lorentz invariance leads to three types of fermion—Dirac, Weyl and Majorana. Although the existence of Weyl and Majorana fermions as elementary particles in high-energy physics is debated, all three types of fermion have been proposed to exist as low-energy, long-wavelength quasiparticle excitations in condensed-matter systems. The existence of Dirac and Weyl fermions in condensed-matter systems has been confirmed experimentally, and that of Majorana fermions is supported by various experiments. However, in condensed-matter systems, fermions in crystals are constrained by the symmetries of the 230 crystal space groups rather than by Lorentz invariance, giving rise to the possibility of finding other types of fermionic excitation that have no counterparts in high-energy physics. Here we use angle-resolved photoemission spectroscopy to demonstrate the existence of a triply degenerate point in the electronic structure of crystalline molybdenum phosphide. Quasiparticle excitations near a triply degenerate point are three-component fermions, beyond the conventional Dirac-Weyl-Majorana classification, which attributes Dirac and Weyl fermions to four- and two-fold degenerate points, respectively. We also observe pairs of Weyl points in the bulk electronic structure of the crystal that coexist with the three-component fermions. This material thus represents a platform for studying the interplay between different types of fermions. Our experimental discovery opens up a way of exploring the new physics of unconventional fermions in condensed-matter systems.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. Effect of dislocations on the open-circuit voltage, short-circuit current and efficiency of heteroepitaxial indium phosphide solar cells

    Science.gov (United States)

    Jain, Raj K.; Flood, Dennis J.

    1990-01-01

    Excellent radiation resistance of indium phosphide solar cells makes them a promising candidate for space power applications, but the present high cost of starting substrates may inhibit their large scale use. Thin film indium phosphide cells grown on Si or GaAs substrates have exhibited low efficiencies, because of the generation and propagation of large number of dislocations. Dislocation densities were calculated and its influence on the open circuit voltage, short circuit current, and efficiency of heteroepitaxial indium phosphide cells was studied using the PC-1D. Dislocations act as predominant recombination centers and are required to be controlled by proper transition layers and improved growth techniques. It is shown that heteroepitaxial grown cells could achieve efficiencies in excess of 18 percent AMO by controlling the number of dislocations. The effect of emitter thickness and surface recombination velocity on the cell performance parameters vs. dislocation density is also studied.

  11. Selectivity control of photosensitive structures based on gallium arsenide phosphide solid solutions by changing the rate of surface recombination

    International Nuclear Information System (INIS)

    Tarasov, S A; Andreev, M Y; Lamkin, I A; Solomonov, A V

    2016-01-01

    In this paper, we demonstrate the effect of surface recombination on spectral sensitivity of structures based on gallium arsenide phosphide solid solutions. Simulation of the effect for structures based on a p-n junction and a Schottky barrier was carried out. Photodetectors with different rates of surface recombination were fabricated by using different methods of preliminary treatment of the semiconductor surface. We experimentally demonstrated the possibility to control photodetector selectivity by altering the rate of surface recombination. The full width at half maximum was reduced by almost 4 times, while a relatively small decrease in sensitivity at the maximum was observed. (paper)

  12. Studies of the pressure dependence of the charge density distribution in cerium phosphide by the maximum-entropy method

    CERN Document Server

    Ishimatsu, N; Takata, M; Nishibori, E; Sakata, M; Hayashi, J; Shirotani, I; Shimomura, O

    2002-01-01

    The physical properties relating to 4f electrons in cerium phosphide, especially the temperature dependence and the isomorphous transition that occurs at around 10 GPa, were studied by means of x-ray powder diffraction and charge density distribution maps derived by the maximum-entropy method. The compressibility of CeP was exactly determined using a helium pressure medium and the anomaly that indicated the isomorphous transition was observed in the compressibility. We also discuss the anisotropic charge density distribution of Ce ions and its temperature dependence.

  13. Diffusion length variation in 0.5- and 3-MeV-proton-irradiated, heteroepitaxial indium phosphide solar cells

    Science.gov (United States)

    Jain, Raj K.; Weinberg, Irving; Flood, Dennis J.

    1993-01-01

    Indium phosphide (InP) solar cells are more radiation resistant than gallium arsenide (GaAs) and silicon (Si) solar cells, and their growth by heteroepitaxy offers additional advantages leading to the development of light weight, mechanically strong, and cost-effective cells. Changes in heteroepitaxial InP cell efficiency under 0.5- and 3-MeV proton irradiations have been explained by the variation in the minority-carrier diffusion length. The base diffusion length versus proton fluence was calculated by simulating the cell performance. The diffusion length damage coefficient, K(sub L), was also plotted as a function of proton fluence.

  14. Byproduct-free mass production of compound semiconductor nanowires: zinc phosphide

    Science.gov (United States)

    Chen, Yixi; Polinnaya, Rakesh; Vaddiraju, Sreeram

    2018-05-01

    A method for the mass production of compound semiconductor nanowires that involves the direct reaction of component elements in a chemical vapor deposition chamber (CVD) is presented. This method results in nanowires, without the associated production of any other byproducts such as nanoparticles or three-dimensional (3D) bulk crystals. Furthermore, no unreacted reactants remain mixed with the nanowire product in this method. This byproduct-free nanowire production thus circumvents the need to tediously purify and collect nanowires from a mixture of products/reactants after their synthesis. Demonstration made using zinc phosphide (Zn3P2) material system as an example indicated that the direct reaction of zinc microparticles with phosphorus supplied via the vapor phase results in the production of gram quantities of nanowires. To enhance thermal transport and achieve the complete reaction of zinc microparticles, while simultaneously ensuring that the microparticles do not agglomerate into macroscale zinc particles and partly remain unreacted (owing to diffusion limitations), pellets composed of mixtures of zinc and a sacrificial salt, NH4Cl, were employed as the starting material. The sublimation by decomposition of NH4Cl in the early stages of the reaction leaves a highly porous pellet of zinc composed of only zinc microparticles, which allows for inward diffusion of phosphorus/outward diffusion of zinc and the complete conversion of zinc into Zn3P2 nanowires. NH4Cl also aids in removal of any native oxide layer present on the zinc microparticles that may prevent their reaction with phosphorus. This method may be used to mass produce many other nanowires in a byproduct-free manner, besides Zn3P2.

  15. Pushing indium phosphide quantum dot emission deeper into the near infrared

    Science.gov (United States)

    Saeboe, A. M.; Kays, J.; Mahler, A. H.; Dennis, A. M.

    2018-02-01

    Cadmium-free near infrared (NIR) emitting quantum dots (QDs) have significant potential for multiplexed tissue-depth imaging applications in the first optical tissue window (i.e., 650 - 900 nm). Indium phosphide (InP) chemistry provides one of the more promising cadmium-free options for biomedical imaging, but the full tunability of this material has not yet been achieved. Specifically, InP QD emission has been tuned from 480 - 730 nm in previous literature reports, but examples of samples emitting from 730 nm to the InP bulk bandgap limit of 925 nm are lacking. We hypothesize that by generating inverted structures comprising ZnSe/InP/ZnS in a core/shell/shell heterostructure, optical emission from the InP shell can be tuned by changing the InP shell thickness, including pushing deeper into the NIR than current InP QDs. Colloidal synthesis methods including hot injection precipitation of the ZnSe core and a modified successive ion layer adsorption and reaction (SILAR) method for stepwise shell deposition were used to promote growth of core/shell/shell materials with varying thicknesses of the InP shell. By controlling the number of injections of indium and phosphorous precursor material, the emission peak was tuned from 515 nm to 845 nm (2.41 - 1.47 eV) with consistent full width half maximum (FWHM) values of the emission peak 0.32 eV. To confer water solubility, the nanoparticles were encapsulated in PEGylated phospholipid micelles, and multiplexing of NIR-emitting InP QDs was demonstrated using an IVIS imaging system. These materials show potential for multiplexed imaging of targeted QD contrast agents in the first optical tissue window.

  16. Study of grown-in and radiation-induced defects in indium phosphide

    International Nuclear Information System (INIS)

    Shaban, E.H.

    1986-01-01

    This research is focused on (1) conducting detailed theoretical and experimental study of grown-in and radiation-induced defects in liquid encapsulated Czohralski (LEC) grown, Zn-doped P-type indium phosphide (InP), (2) identifying the physical origin of the defects detected using Deep Level Transient Spectroscopy (DLTS) method, and (3) and developing a second-order model to interpret the presence of nonexponential capacitance transients in DLTS method. Analysis of grown-in and radiation-induced defects in P-type InP is undertaken. The main research results are summarized as follows: (1) DLTS analysis of grown-in defects in liquid LEC-grown, Zn-doped, P-type InP is made in this study. A single-hole trap of E/sub v/ + 0.52 eV is detected with a trap density of 1.8 x 10 15 cm -3 . The physical origin of this hole trap is attributed to a phosphorus vacancy or phosphorus interstitial-related defect. (2) One-MeV electron-irradiated P-type InP introduced two new hole traps, namely E/sub v/ + 0.34 and E/sub v/ + 0.58 eV with introduction rates (dN/sub T/d phi) of 0.4 and 1.2 per electron-cm, respectively. (3) A theoretical model is developed to interpret nonexponential capacitance transients in a deep-level transient spectroscopy method when the capture process competes with the dominant thermal-emission process

  17. Atomistic investigations on the mechanical properties and fracture mechanisms of indium phosphide nanowires.

    Science.gov (United States)

    Pial, Turash Haque; Rakib, Tawfiqur; Mojumder, Satyajit; Motalab, Mohammad; Akanda, M A Salam

    2018-03-28

    The mechanical properties of indium phosphide (InP) nanowires are an emerging issue due to the promising applications of these nanowires in nanoelectromechanical and microelectromechanical devices. In this study, molecular dynamics simulations of zincblende (ZB) and wurtzite (WZ) crystal structured InP nanowires (NWs) are presented under uniaxial tension at varying sizes and temperatures. It is observed that the tensile strengths of both types of NWs show inverse relationships with temperature, but are independent of the size of the nanowires. Moreover, applied load causes brittle fracture by nucleating cleavage on ZB and WZ NWs. When the tensile load is applied along the [001] direction, the direction of the cleavage planes of ZB NWs changes with temperature. It is found that the {111} planes are the cleavage planes at lower temperatures; on the other hand, the {110} cleavage planes are activated at elevated temperatures. In the case of WZ NWs, fracture of the material is observed to occur by cleaving along the (0001) plane irrespective of temperature when the tensile load is applied along the [0001] direction. Furthermore, the WZ NWs of InP show considerably higher strength than their ZB counterparts. Finally, the impact of strain rate on the failure behavior of InP NWs is also studied, and higher fracture strengths and strains at higher strain rates are found. With increasing strain rate, the number of cleavages also increases in the NWs. This paper also provides in-depth understanding of the failure behavior of InP NWs, which will aid the design of efficient InP NWs-based devices.

  18. 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.

  19. 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

  20. Surface-oxidized cobalt phosphide used as high efficient electrocatalyst in activated carbon air-cathode microbial fuel cell

    Science.gov (United States)

    Yang, Tingting; Wang, Zhong; Li, Kexun; Liu, Yi; Liu, Di; Wang, Junjie

    2017-09-01

    Herein, we report a simplistic method to fabricate the surface-oxidized cobalt phosphide (CoP) nanocrystals (NCs), which is used as electrocatalyst for oxygen reduction reaction (ORR) in microbial fuel cell (MFC) for the first time. The corallite-like CoP NCs are successfully prepared by a hydrothermal reaction following a phosphating treatment in N2 atmosphere. When used as an ORR catalyst, cobalt phosphide shows comparable onset potential, inferior resistance, as well as a small Tafel slope with long-term stability in neutral media. The maximum power density of MFC embellished with 10% CoP reached 1914.4 ± 59.7 mW m-2, which is 108.5% higher than the control. The four-electron pathway, observed by the RDE, plays a crucial role in electrochemical catalytic activity. In addition, material characterizations indicate that the surface oxide layer (CoOx) around the metallic CoP core is important and beneficial for ORR. Accordingly, it can be expected that the as-synthesized CoP will be a promising candidate of the non-precious metal ORR electrocatalysts for electrochemical energy applications.

  1. Theoretical prediction of sandwiched two-dimensional phosphide binary compound sheets with tunable bandgaps and anisotropic physical properties

    Science.gov (United States)

    Zhang, C. Y.; Yu, M.

    2018-03-01

    Atomic layers of GaP and InP binary compounds with unique anisotropic structural, electronic and mechanical properties have been predicted from first-principle molecular dynamics simulations. These new members of the phosphide binary compound family stabilize to a sandwiched two-dimensional (2D) crystalline structure with orthorhombic lattice symmetry and high buckling of 2.14 Å-2.46 Å. Their vibration modes are similar to those of phosphorene with six Raman active modes ranging from ˜80 cm-1 to 400 cm-1. The speeds of sound in their phonon dispersions reflect anisotropy in their elastic constants, which was further confirmed by their strong directional dependence of Young’s moduli and effective nonlinear elastic moduli. They show wide bandgap semiconductor behavior with fundamental bandgaps of 2.89 eV for GaP and 2.59 eV for InP, respectively, even wider than their bulk counterparts. Such bandgaps were found to be tunable under strain. In particular, a direct-indirect bandgap transition was found under certain strains along zigzag or biaxial orientations, reflecting their promising applications in strain-induced bandgap engineering in nanoelectronics and photovoltaics. Feasible pathways to realize these novel 2D phosphide compounds are also proposed.

  2. Study of laboratory profile in patients with aluminium phosphide poisoning in the southwest of Iran from 2010 to 2015

    Directory of Open Access Journals (Sweden)

    Farkhonde Jamshidi

    2017-03-01

    Full Text Available Introduction : Aluminium phosphide or rice tablet is one of the most common pesticides around the world. The substance releases phosphine gas in the presence of water, steam or stomach acid which can lead to poisoning. Phosphine poisoning is more about suicide the number of which is increasing day by day. Two-thirds of patients lose their lives. The aim of this study was to evaluate the data on the clinical epidemiology and laboratory changes in patients poisoned with rice tablets. Material and methods : A total of 23 patients poisoned by aluminium phosphide who referred to Ahvaz Razi hospital within the period of 2010–2015 were studied. The data were analyzed using descriptive statistics and statistical tests. Results : The mean age of the patients was 27.2 ±7.3 years and 60.9% of the patients were male. 8.7% of the patients had hyponatremia and 21.7% of the patients had hypokalemia. In the majority of cases the amount of sodium and potassium was normal. 91% of patients had acidosis and serum bicarbonate was reduced in the majority of cases. The average interval between poisoning and admission was 1.48 ±0.76 hours. Conclusions : The pattern to change the electrolytes and other laboratory factors could be a good marker of the severity of the poisoning and the clinical conditions of the patient, which requires more specific research to prove the process.

  3. 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%.

  4. Potential for photocatalytic degradation of the potassic diclofenac using scandium and silver modified titanium dioxide thin films; Potencial de degradacao fotocatalitica do diclofenaco potassico utilizando filmes finos de dioxido de titanio modificado com escandio e prata

    Energy Technology Data Exchange (ETDEWEB)

    Ciola, R.A.; Oliveira, C.T.; Lopes, S.A.; Cavalheiro, A.A., E-mail: rafaelciola@hotmail.com [Universidade Estadual de Mato Grosso do Sul (UFMS), Navirai, MS (Brazil). Centro de Pesquisas Tecnologicas em Recursos Naturais

    2011-07-01

    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)

  5. Comparative studies on mitochondrial electron transport chain complexes of Sitophilus zeamais treated with allyl isothiocyanate and calcium phosphide.

    Science.gov (United States)

    Zhang, Chao; Wu, Hua; Zhao, Yuan; Ma, Zhiqing; Zhang, Xing

    2016-01-01

    With Sitophilus zeamais as the target organism, the present study for the first time attempted to elucidate the comparative effects between allyl isothiocyanate (AITC) and calcium phosphide (Ca3P2), exposure on mitochondrial electron transport chain (ETC.) complex I & IV and their downstream effects on enzymes relevant to reactive oxygen species (ROS). In vivo, both AITC and Ca3P2 inhibited complex I and IV with similar downstream effects. In contrast with Ca3P2, the inhibition of complex I caused by AITC was dependent on time and dose. In vitro, AITC inhibited complex IV more significantly than complex I. These results indicate that mitochondrial complex IV is the primary target of AITC, and that complex I is another potential target. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. ZrCu2P2 and HfCu2P2 phosphides and their crystal structure

    International Nuclear Information System (INIS)

    Lomnitskaya, Ya.F.

    1986-01-01

    Isostructural ZrCu 2 P 2 and HfCu 2 P 2 compounds are prepared for the first time. X-ray diffraction analysis (of powder, DRON-2.0 diffractometer, FeKsub(α) radiation) was used to study crystal structure of HfCu 2 P 2 phosphide belonging to the CaAl 2 Si 2 structural type (sp. group P anti 3 m 1, R=0.095). Lattice parameters the compounds are as follows: for ZrCu 2 P 2 a=0.3810(1), c=0.6184(5); for HfCu 2 P 2 a=0.3799(1), c=0.6160(2) (nm). Atomic parameters in the HfCu 2 P 2 structure and interatomic distances are determined

  7. Effects of P/Ni ratio and Ni content on performance of γ-Al_2O_3-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

    International Nuclear Information System (INIS)

    Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang

    2016-01-01

    Graphical abstract: - Highlights: • The formation of AlPO_4 was unfavorable for that of nickel phosphides. • The phase compositions of nickel phosphide depended on the amount of reduced P. • Catalytic activity was determined by surface Ni site density and catalyst acidity. • HDO pathway was promoted by increasing P/Ni ratio and Ni content. • Nickel phosphide gave much higher carbon yield and lower H_2 consumption than Ni. - Abstract: γ-Al_2O_3-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0–2.5) and Ni content (m = 5–15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al_2O_3 was also studied for comparison. It was found that the formation of AlPO_4 in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni_3P, Ni_1_2P_5 and Ni_2P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al_2O_3, the mNi-Pn catalysts showed much lower activities for decarbonylation, C−C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and acid site. Again, the hydrodeoxygenation pathway of methyl

  8. Enhanced activity and durability of platinum anode catalyst by the modification of cobalt phosphide for direct methanol fuel cells

    International Nuclear Information System (INIS)

    Li, Xiang; Wang, Hongjuan; Yu, Hao; Liu, Ziwu; Wang, Haihui; Peng, Feng

    2015-01-01

    Graphical abstract: A novel Pt/CoP/CNTs electrocatalyst with has been designed and prepared, which exhibits high activity and stability for methanol oxidation reaction. - Highlights: • Pt-cobalt phosphide catalyst supported on carbon nanotubes (Pt/CoP/CNTs) is designed. • Pt/CoP/CNTs exhibit high activity and stability for methanol oxidation reaction(MOR). • The effect of CoP content on electrocatalytic performances for MOR is studied. • CoP decreases the Pt particle size and increases the electrochemical surface areas. • The interaction between Pt and CoP is evidenced by X-ray photoelectron spectroscopy. - Abstract: In this study, carbon nanotubes (CNTs) supported Pt-cobalt phosphide (CoP) electrocatalyst (Pt/CoP/CNTs) is designed and prepared for methanol oxidation (MOR) for the first time. The modification of CoP decreases the Pt particle size significantly and increases the electrochemical surface areas due to the interaction between Pt and CoP, which is evidenced by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Among all these catalysts, Pt/4%CoP/CNTs catalyst exhibits the best MOR activity of 1600 mA mg −1 Pt , which is six times that of Pt/CNTs. Moreover, this catalyst also exhibits the higher onset current density and steady current density than the other Pt-based catalysts. The work provides a promising method to develop the highly active and stable Pt-based catalyst for direct methanol fuel cells.

  9. 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.

  10. 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.

  11. Scandium complexes: physico-chemical study and evaluation of stability in vitro and in vivo for nuclear medicine application

    International Nuclear Information System (INIS)

    Kerdjoudj, Rabha

    2014-01-01

    Among the different isotopes of Scandium that can be used in nuclear medicine may be mentioned the 47 Sc and 44 Sc. The first decays by emitting an electron associated with a 159 keV gamma can thus be used either for radiotherapy or TEMP imaging. The 44 Sc (3.97 h) decays in 94.27% in case by emitting a positron, with a γ photon energy equal to 1.157 MeV. This isotope is then an ideal candidate for applications in PET imaging. Currently, the Cyclotron of high energy and high intensity ARRONAX produce 44 Sc and co-produces the isomeric state the 44m Sc (2.44 d). The 44m Sc has properties (E(γ) = 270 keV, 98.8%), which allows to consider its use as a potential in vivo generator. Previous work had demonstrated that the DOTA ligand is most suitable and stable for Sc. This thesis aims; make in evidence the feasibility of the in vivo 44m / 44 Sc generator. Initially a procedure was optimized and validated for the production of 44m / 44 Sc with a high specific activity and chemical purity. Radiolabeling of DOTA conjugated peptides was then developed and optimized. Theoretical and experimental studies have been performed in order to demonstrate the feasibility of 44m / 44 Sc as a potential in vivo generator. Finally, in vitro stability studies on radiolabeled 44m / 44 Sc complexes were performed, followed by biodistribution studies and PET imaging. (author)

  12. Topotactic Conversion of Copper(I) Phosphide Nanowires for Sensitive Electrochemical Detection of H2O2 Release from Living Cells.

    Science.gov (United States)

    Li, Zhenzhen; Xin, Yanmei; Wu, Wenlong; Fu, Baihe; Zhang, Zhonghai

    2016-08-02

    In this work, we clearly demonstrate for the first time the use of transition-metal phosphides to set up a new cathodic analysis platform for sensitive and selective electrochemical nonenzymatic detection of H2O2. With the help of a facile topotactic conversion method, the noble metal-free electrocatalyst of copper(I) phosphide nanowires on three-dimensional porous copper foam (Cu3P NWs/CF) is fabricated with electrochemical anodized Cu(OH)2 NWs as precursor. The Cu3P NWs/CF-based sensor presents excellent electrocatalytic activity for H2O2 reduction with a detection limit of 2 nM, the lowest detection limit achieved by noble-metal free electrocatalyst, which guarantees the possibility of sensitive and reliable detection of H2O2 release from living tumorigenic cells, thus showing the potential application as a sensitive cancer cell detection probe.

  13. In situ X-ray absorption fine structure studies on the structure of nickel phosphide catalyst supported on K-USY

    CERN Document Server

    Kawai, T; Suzuki, S

    2003-01-01

    Local structure around Ni in a nickel phosphide catalyst supported on K-USY was investigated by an situ X-ray absorption fine structure (XAFS) method during the reduction process of the catalyst and the hydrodesulfurization (HDS) reaction of thiophene. In the passivated sample, Ni phosphide was partially oxidized but after the reduction, 1.1 nm diameter Ni sub 2 P particles were formed with Ni-P and Ni-Ni distances at 0.218 and 0.261 nm, respectively, corresponding to those of bulk Ni sub 2 P. In situ XAFS cleary revealed that the Ni sub 2 P structure was stable under reaction conditions and was an active structure for the HDS process.

  14. Aqueous corrosion of phosphide minerals from iron meteorites: a highly reactive source of prebiotic phosphorus on the surface of the early Earth.

    Science.gov (United States)

    Pasek, Matthew A; Lauretta, Dante S

    2005-08-01

    We present the results of an experimental study of aqueous corrosion of Fe-phosphide under conditions relevant to the early Earth. The results strongly suggest that iron meteorites were an important source of reactive phosphorus (P), a requirement for the formation of P-based life. We further demonstrate that iron meteorites were an abundant source of phosphide minerals early in Earth history. Phosphide corrosion was studied in five different solutions: deionized water, deionized water buffered with sodium bicarbonate, deionized water with dissolved magnesium and calcium chlorides, deionized water containing ethanol and acetic acid, and deionized water containing the chlorides, ethanol, and acetic acid. Experiments were performed in the presence of both air and pure Ar gas to evaluate the effect of atmospheric chemistry. Phosphide corrosion in deionized water results in a metastable mixture of mixed-valence, P-bearing ions including pyrophosphate and triphosphate, key components for metabolism in modern life. In a pH-buffered solution of NaHCO(3), the condensed and reduced species diphosphonate is an abundant corrosion product. Corrosion in ethanol- and acetic acid-containing solutions yields additional P-bearing organic molecules, including acetyl phosphonate and a cyclic triphosphorus molecule. Phosphonate is a major corrosion product of all experiments and is the only P-bearing molecule that persists in solutions with high concentrations of magnesium and calcium chlorides, which suggests that phosphonate may have been a primitive oceanic source of P. The stability and reactivity of phosphonate and hypophosphite in solution were investigated to elucidate reaction mechanisms and the role of mineral catalysts on P-solution chemistry. Phosphonate oxidation is rapid in the presence of Fe metal but negligible in the presence of magnetite and in the control sample. The rate of hypophosphite oxidation is independent of reaction substrate.

  15. Determination of scandium in acid mine drainage by ICP-OES with flow injection on-line preconcentration using oxidized multiwalled carbon nanotubes.

    Science.gov (United States)

    Jerez, Javier; Isaguirre, Andrea C; Bazán, Cristian; Martinez, Luis D; Cerutti, Soledad

    2014-06-01

    An on-line scandium preconcentration and determination system implemented with inductively coupled plasma optical emission spectrometry associated with flow injection was studied. Trace amounts of scandium were preconcentrated by sorption on a minicolumn packed with oxidized multiwalled carbon nanotubes, at pH 1.5. The retained analyte was removed from the minicolumn with 30% (v/v) nitric acid. A total enrichment factor of 225-fold was obtained within a preconcentration time of 300 s (for a 25 mL sample volume). The overall time required for preconcentration and elution of 25 mL of sample was about 6 min; the throughput was about 10 samples per hour. The value of the detection limit was 4 ng L(-1) and the precision for 10 replicate determinations at 100 ng L(-1) Sc level was 5% relative standard deviation, calculated from the peak heights obtained. The calibration graph using the preconcentration system was linear with a correlation coefficient of 0.9996 at levels near the detection limits up to at least 10 mg L(-1). After optimization, the method was successfully applied to the determination of Sc in an acid drainage from an abandoned mine located in the province of San Luis, Argentina. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Effects of scandium and zirconium combination alloying on as-cast microstructure and mechanical properties of Al-4Cu-1.5Mg alloy

    Directory of Open Access Journals (Sweden)

    Xiang Qingchun

    2011-02-01

    Full Text Available The influences of minor scandium and zirconium combination alloying on the as-cast microstructure and mechanical properties of Al-4Cu-1.5Mg alloy have been experimentally investigated. The experimental results show that when the minor elements of scandium and zirconium are simultaneously added into the Al-4Cu-1.5Mg alloy, the as-cast microstructure of the alloy is effectively modified and the grains of the alloy are greatly refined. The coarse dendrites in the microstructure of the alloy without Sc and Zr additions are refined to the uniform and fine equiaxed grains. As the additions of Sc and Zr are 0.4% and 0.2%, respectively, the tensile strength, yield strength and elongation of the alloy are relatively better, which are 275.0 MPa, 176.0 MPa and 8.0% respectively. The tensile strength is increased by 55.3%, and the elongation is nearly raised three times, compared with those of the alloy without Sc and Zr additions.

  17. Synthesis, structures, and electroluminescent properties of scandium N,O-chelated complexes toward near-white organic light-emitting diodes.

    Science.gov (United States)

    Katkova, Marina A; Balashova, Tatyana V; Ilichev, Vasilii A; Konev, Alexey N; Isachenkov, Nikolai A; Fukin, Georgy K; Ketkov, Sergey Yu; Bochkarev, Mikhail N

    2010-06-07

    Three members of a new class of electroluminescent, neutral, and monomeric scandium N,O-chelate complexes, namely, Sc(III)-tris-2-(2-benzoimidazol-2-yl)phenolate (1), Sc(III)-tris-2-(2-benzoxyazol-2-yl)phenolate (2), and Sc(III)-tris-2-(2-benzothiazol-2-yl)phenolate (3), have been prepared and X-ray characterized. DFT calculations have been performed. In contrast to the most frequently applied dual or multiple dopants in multilayer white OLED devices, all our simpler devices with the configuration of indium tin oxide/N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine/neat scandium complex/Yb exhibit close to near-white emission with a blue hue (CIE(x,y) = 0.2147, 0.2379) in the case of 1, a cyan hue (0.2702, 0.3524) in the case of 2, and a yellowish hue (0.3468; 0.4284) in the case of 3.

  18. Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Motahareh Soltani

    2016-08-01

    Full Text Available Objectives: Aluminium phosphide (AlP is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3, a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. Methods: This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Results: Activated charcoal significantly reduced the volume of released gas (P <0.01. Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01. A gaseous adduct was formed in the reaction between pure AlP and boric acid. Conclusion: These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning.

  19. An electrocardiographic, molecular and biochemical approach to explore the cardioprotective effect of vasopressin and milrinone against phosphide toxicity in rats.

    Science.gov (United States)

    Jafari, Abbas; Baghaei, Amir; Solgi, Reza; Baeeri, Maryam; Chamanara, Mohsen; Hassani, Shokoufeh; Gholami, Mahdi; Ostad, Seyed Nasser; Sharifzadeh, Moahmmad; Abdollahi, Mohammad

    2015-06-01

    The present study was conducted to identify the protective effect of vasopressin (AVP) and milrinone on cardiovascular function, mitochondrial complex activities, cellular ATP reserve, oxidative stress, and apoptosis in rats poisoned by aluminum phosphide (AlP). Rats were divided into five groups (n = 12) including control, AlP (12.5 mg/kg), AlP + AVP (2.0 Units/kg), AlP + milrinone (0.25 mg/kg) and AlP + AVP + milrinone. After treatment, the animals were connected to an electronic cardiovascular monitoring device to monitor electrocardiographic (ECG) parameter. Finally, oxidative stress biomarkers, mitochondrial complex activities, ADP/ATP ratio and apoptosis were evaluated on the heart tissues. Results indicated that AlP administration induced ECG abnormalities along with a decline in blood pressure and heart rate. AVP and milrinone significantly ameliorated these changes in all treated groups. Considerable protective effects on oxidative stress biomarkers, complex IV activity, ADP/ATP ratio and caspase-3 and -9 activities in treated groups were also found. These findings were supported by flow cytometry assay of cardiomyocytes. In conclusion, administration of AVP and milrinone, not only improve cardiovascular functions in AlP poisoned rats in the short time, but after a long time can also restore mitochondrial function and ATP level and reduce the oxidative damage, which prevent cardiomyocytes from entering the apoptotic phase. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Hydrazine-Assisted Formation of Indium Phosphide (InP)-Based Nanowires and Core-Shell Composites.

    Science.gov (United States)

    Patzke, Greta R; Kontic, Roman; Shiolashvili, Zeinab; Makhatadze, Nino; Jishiashvili, David

    2012-12-27

    Indium phosphide nanowires (InP NWs) are accessible at 440 °C from a novel vapor phase deposition approach from crystalline InP sources in hydrazine atmospheres containing 3 mol % H₂O. Uniform zinc blende (ZB) InP NWs with diameters around 20 nm and lengths up to several tens of micrometers are preferably deposited on Si substrates. InP particle sizes further increase with the deposition temperature. The straightforward protocol was extended on the one-step formation of new core-shell InP-Ga NWs from mixed InP/Ga source materials. Composite nanocables with diameters below 20 nm and shells of amorphous gallium oxide are obtained at low deposition temperatures around 350 °C. Furthermore, InP/Zn sources afford InP NWs with amorphous Zn/P/O-coatings at slightly higher temperatures (400 °C) from analogous setups. At 450 °C, the smooth outer layer of InP-Zn NWs is transformed into bead-shaped coatings. The novel combinations of the key semiconductor InP with isotropic insulator shell materials open up interesting application perspectives in nanoelectronics.

  1. Pure and carbon-doped boron phosphide (6,0) zigzag nanotube: A computational NMR study

    Energy Technology Data Exchange (ETDEWEB)

    Arshadi, S., E-mail: sattar_arshadi@yahoo.com [Department of Chemistry, Payame Noor University, 19395-4697, I.R. of Iran (Iran, Islamic Republic of); Bekhradnia, A.R., E-mail: abekhradnia@gmail.com [Pharmaceutical Sciences Research Center, Department of Medicinal Chemistry, Mazandaran University of Medical Sciences, Sari (Iran, Islamic Republic of); Department of Chemistry and Molecular Biology, Gothenburg University, Gothenburg (Sweden); Alipour, F.; Abedini, S. [Department of Chemistry, Payame Noor University, 19395-4697, I.R. of Iran (Iran, Islamic Republic of)

    2015-11-15

    Calculations were performed for investigation of the properties of the electronic structure of Carbon- Doped Boron Phosphide Nanotube (CDBPNT). Pristine and three models of C-doped structures of (6,0) zigzag BPNT were studied at density functional theory (DFT) in combination with 6-311G* basis set using Gaussian package of program. The calculated parameters reveal that various {sup 11}B and {sup 31}P nuclei are divided into some layers with equivalent electrostatic properties. The electronic structure properties are highly influenced by replacement of {sup 11}B and {sup 31}P atoms by {sup 12}C atoms in pristine model. Furthermore, the HOMO−LUMO gap energy for suggested doped models (I), (II) and (III) were lower than pure BPNT pristine systems. The dipole moment values of models (II) and (III) were decreased to 1.788 and 1.789, respectively while the dipole moments of model (I) were enhanced to 4.373, in compare to pure pristine one (2.586). The magnitude of changes in Chemical Shielding (CS) tensor parameters revealed that the electron density at the site of {sup 31}P was higher than that at the site of {sup 11}B due to carbon doping.

  2. Two anionically derivatized scandium oxoselenates(IV): ScF[SeO3] and Sc2O2[SeO3

    Science.gov (United States)

    Greiner, Stefan; Chou, Sheng-Chun; Schleid, Thomas

    2017-02-01

    Scandium fluoride oxoselenate(IV) ScF[SeO3] and scandium oxide oxoselenate(IV) Sc2O2[SeO3] could be synthesized through solid-state reactions. ScF[SeO3] was obtained phase-pure, by reacting mixtures of Sc2O3, ScF3 and SeO2 (molar ratio: 1:1:3) together with CsBr as fluxing agent in corundum crucibles embedded into evacuated glassy silica ampoules after firing at 700 °C for seven days. Sc2O2[SeO3] first emerged as by-product during the attempts to synthesize ScCl[SeO3] following aforementioned synthesis route and could later be reproduced from appropriate Sc2O3/SeO3 mixtures. ScF[SeO3] crystallizes monoclinically in space group P21/m with a=406.43(2), b =661.09(4), c=632.35(4) pm, β=93.298(3)° and Z=2. Sc2O2[SeO3] also crystallizes in the monoclinic system, but in space group P21/n with a=786.02(6), b=527.98(4), c=1086.11(8) pm, β=108.672(3)° for Z=4. The crystal structures of both compounds are strongly influenced by the stereochemically active lone pairs of the ψ1-tetrahedral [SeO3]2- anions. They also show partial structures, where the derivatizing F- or O2- anions play an important role. For ScF[SeO3] chains of the composition 2+∞ 1[FS c 2 / 2 ] form from connected [FSc2]5+ dumbbells, while [OSc3]7+ pyramids and [OSc4]10+ tetrahedra units are condensed to layers according to 2+ ∞ 2[O2Sc2 ] in Sc2O2[SeO3].

  3. Copper scandium zirconium phosphate

    DEFF Research Database (Denmark)

    Bond, Andrew David; Warner, Terence Edwin

    2013-01-01

    The title compound, with nominal formula Cu(2)ScZr(PO(4))(3), has a beige coloration and displays fast Cu(+) cation conduction at elevated temperatures. It adopts a NASICON-type structure in the space group R3c. The examined crystal was an obverse-reverse twin with approximately equal twin compon...

  4. Zeeman spectrum of scandium

    International Nuclear Information System (INIS)

    Lulu, B.A.

    1980-09-01

    The spectra of Sc I, Sc II, Sc III, and Sc IV are analyzed through the use of the Zeeman effect. A sliding spark of the author's design is used in conjunction with a 27 kilogauss electromagnet. The spectra have (reciprocal) dispersions of 0.2 to 0.5 A/mm. 10 Sc I levels, 16 Sc II levels and 5 Sc III levels show Zeeman splitting. No Sc IV Zeeman patterns were observed. 2 Sc I, 4 Sc II, and all of the Sc III level data are new

  5. The effect of N-acetyl cysteine (NAC) on aluminum phosphide poisoning inducing cardiovascular toxicity: a case-control study.

    Science.gov (United States)

    Taghaddosinejad, Fakhreddin; Farzaneh, Esmaeil; Ghazanfari-Nasrabad, Mahdi; Eizadi-Mood, Nastaran; Hajihosseini, Morteza; Mehrpour, Omid

    2016-01-01

    Aluminum phosphide (AlP) is a very effective indoor and outdoor pesticide. We investigated the effects of N-acetyl cysteine (NAC) on the survival time, hemodynamics, and cardiac biochemical parameters at various time intervals in some cases of AlP poisoning. This research was a case-control study to evaluate 63 AlP poisoned patients during 2010-2012. Patients with cardiovascular complications of AlP to be treated with intravenous NAC plus conventional treatment were considered as the case group and compared with patients who did not receive NAC. NAC infusion was administered to the case group at 300 mg/kg for 20 h. The data gathered included age, sex, heart rate, Systolic blood pressure (SBP), creatine phosphokinase (CPK), creatine kinase MB (CK-MB), and ECG at the admission time and 12, 18, and 24 h after admission. Analysis of repeated measures was performed to check the variability of parameters over time. The mean ages in the case and control groups were 26.65 ± 1.06 (19-37 years) and 28.39 ± 1.11 (18-37 years), respectively (P = 0.266). Most of the patients were female (56.5%). CK-MB means were significantly different between the two groups, but no differences between the other variables were observed. Also, CK-MB, CPK, heart rate, and systolic blood pressure means became significantly different over time (0, 12, 18, and 24 h) in both groups (P managed by the positive role of NAC as the biochemical index of cardiotoxicity was found to elevate in both the case and control groups. Therefore, for the management protocol optimization, NAC evaluation should be done in further cases.

  6. Tailored surface structure of LiFePO4/C nanofibers by phosphidation and their electrochemical superiority for lithium rechargeable batteries.

    Science.gov (United States)

    Lee, Yoon Cheol; Han, Dong-Wook; Park, Mihui; Jo, Mi Ru; Kang, Seung Ho; Lee, Ju Kyung; Kang, Yong-Mook

    2014-06-25

    We offer a brand new strategy for enhancing Li ion transport at the surface of LiFePO4/C nanofibers through noble Li ion conducting pathways built along reduced carbon webs by phosphorus. Pristine LiFePO4/C nanofibers composed of 1-dimensional (1D) LiFePO4 nanofibers with thick carbon coating layers on the surfaces of the nanofibers were prepared by the electrospinning technique. These dense and thick carbon layers prevented not only electrolyte penetration into the inner LiFePO4 nanofibers but also facile Li ion transport at the electrode/electrolyte interface. In contrast, the existing strong interactions between the carbon and oxygen atoms on the surface of the pristine LiFePO4/C nanofibers were weakened or partly broken by the adhesion of phosphorus, thereby improving Li ion migration through the thick carbon layers on the surfaces of the LiFePO4 nanofibers. As a result, the phosphidated LiFePO4/C nanofibers have a higher initial discharge capacity and a greatly improved rate capability when compared with pristine LiFePO4/C nanofibers. Our findings of high Li ion transport induced by phosphidation can be widely applied to other carbon-coated electrode materials.

  7. Hierarchical cobalt poly-phosphide hollow spheres as highly active and stable electrocatalysts for hydrogen evolution over a wide pH range

    Science.gov (United States)

    Wu, Tianli; Pi, Mingyu; Wang, Xiaodeng; Guo, Weimeng; Zhang, Dingke; Chen, Shijian

    2018-01-01

    Exploring highly-efficient and low-cost non-noble metal electrocatalyst toward the hydrogen evolution reaction (HER) is highly desired for renewable energy system but remains challenging. In this work, three dimensional hierarchical porous cobalt poly-phosphide hollow spheres (CoP3 HSs) were prepared by topotactic phosphidation of the cobalt-based precursor via vacuum encapsulation technique. As a porous HER cathode, the CoP3 HSs delivers remarkable electrocatalytic performance over the wide pH range. It needs overpotentials of -69 mV and -118 mV with a small Tafel slope of 51 mV dec-1 to obtain current densities of 10 mA cm-2 and 50 mA cm-2, respectively, and maintains its electrocatalytic performance over 30 h in acidic solution. In addition, CoP3 also exhibit superior electrocatalytic performance and stability under neutral and alkaline conditions for the HER. Both experimental measurements and density functional theory (DFT) calculations are performed to explore the mechanism behind the excellent HER performance. The results of our study make the porous CoP3 HSs as a promising electrocatalyst for practical applications toward energy conversion system and present a new way for designing and fabricating HER electrodes through high degree of phosphorization and nano-porous architecture.

  8. Effects of P/Ni ratio and Ni content on performance of γ-Al2O3-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

    Science.gov (United States)

    Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang

    2016-01-01

    γ-Al2O3-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0-2.5) and Ni content (m = 5-15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al2O3 was also studied for comparison. It was found that the formation of AlPO4 in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni3P, Ni12P5 and Ni2P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al2O3, the mNi-Pn catalysts showed much lower activities for decarbonylation, Csbnd C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and acid site. Again, the hydrodeoxygenation pathway of methyl laurate was promoted with increasing P/Ni ratio and Ni content, ascribed to the phase change in the order of Ni, Ni3P, Ni12P5 and Ni2P in the prepared catalysts.

  9. Impact of layer and substrate properties on the surface acoustic wave velocity in scandium doped aluminum nitride based SAW devices on sapphire

    Energy Technology Data Exchange (ETDEWEB)

    Gillinger, M., E-mail: manuel.gillinger@tuwien.ac.at; Knobloch, T.; Schneider, M.; Schmid, U. [Institute of Sensor and Actuator Systems, TU Wien, 1040 Vienna (Austria); Shaposhnikov, K.; Kaltenbacher, M. [Institute of Mechanics and Mechatronics, TU Wien, 1040 Vienna (Austria)

    2016-06-06

    This paper investigates the performance of surface acoustic wave (SAW) devices consisting of reactively sputter deposited scandium doped aluminum nitride (Sc{sub x}Al{sub 1-x}N) thin films as piezoelectric layers on sapphire substrates for wireless sensor or for RF-MEMS applications. To investigate the influence of piezoelectric film thickness on the device properties, samples with thickness ranging from 500 nm up to 3000 nm are fabricated. S{sub 21} measurements and simulations demonstrate that the phase velocity is predominantly influenced by the mass density of the electrode material rather than by the thickness of the piezoelectric film. Additionally, the wave propagation direction is varied by rotating the interdigital transducer structures with respect to the crystal orientation of the substrate. The phase velocity is about 2.5% higher for a-direction compared to m-direction of the sapphire substrate, which is in excellent agreement with the difference in the anisotropic Young's modulus of the substrate corresponding to these directions.

  10. The effect of scandium addition on microstructure and mechanical properties of Al–Si–Mg alloy: A multi-refinement modifier

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Cong, E-mail: xucong55555@gmail.com [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Xiao, Wenlong, E-mail: wlxiao@buaa.edu.cn [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Hanada, Shuji [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Yamagata, Hiroshi [Center for Advanced Die Engineering and Technology, Gifu University, 1-1 Yanagido, Gifu City, Gifu 501-1193 (Japan); Ma, Chaoli [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China)

    2015-12-15

    Effect of scandium (Sc) additions on the microstructure, mechanical properties and fracture behavior of Al–Si–Mg casting alloy (F357) were systematically investigated. It was found that Sc addition caused a multi-refining efficiency on the microstructure of as-cast F357 alloy, including refinement of grains and secondary dendrite arm spacing (SDAS), modification of eutectic Si and harmless disposal of β-Al{sub 5}FeSi phase. Subsequent T6 heat treatment had further induced the complete spheroidization of eutectic Si and precipitation of fine secondary Al{sub 3}Sc dispersoids in the Sc modified alloys. Thus the mechanical properties, especially the ductility, were significantly enhanced by the addition of Sc combined with the heat treatment. The highest ultimate tensile strength, yield strength and elongation were achieved in 0.8 wt.% Sc modified F357 alloy combined with T6 heat treatment. Furthermore, fractographic examinations indicated that the ductile fracture mechanism served as a dominate role in the modified alloys due to the formation of fine, deep and uniformly distributed dimples. - Highlights: • Detailed characterization of the multi-refining microstructure of Sc modified F357 alloy was performed. • The multi-refinement was proposed to refine grain and SDAS, modify eutectic Si and β-phase. • Sc modifier combined with T6 treatment is effective in improving tensile properties. • Modification of eutectic Si in F357 alloy with Sc is consistent with the IIT mechanism.

  11. Serum sample levels of bromine, iron, scandium and zinc in preschool children of Atayal and Bunun aborigines living in central Taiwan

    International Nuclear Information System (INIS)

    Chien-Yi Chen; Ding-Bang Lin; Yuan-Yaw Wei

    2006-01-01

    This study determined bromine, iron, scandium and zinc serum levels in Taiwanese aboriginal preschool children living in remote mountainous areas to increase the understanding of the social, cultural, nutrient and ethnic background of the Taiwanese children. Seventy-three serum samples were taken from two ethnic groups of preschool children, Atayal aborigines (AAPC) and Bunun aborigines (BAPC). Sera of these children were freeze dried. Trace elements in sera were identified by instrumental neutron activation analysis (INAA). The accuracy and precision of INAA was evaluated using certified reference materials: Tomato Leaves (NIST-SRM 1570a) and Lichen (IAEA-336). Statistical analysis identified several different patterns for ethnic groups, gender and age via the two-tailed Student's t-test. Analytical results showed that the ranges of Br, Fe, Sc and Zn in sera were somewhat wide. The Zn serum levels (p < 0.05) and Br serum levels (p < 0.01) in the AAPC were significantly lower than those in the BAPC. However, there were no significant differences in Fe or Sc serum levels between the two groups. Analytical results were compared to published data for different counties. This study is the first investigating trace elements in Taiwanese aborigines and can be used to establish a much-needed serum element database. (author)

  12. Comparative microstructure and electrical property studies of lead scandium tantalate thin films as prepared by LDCVD, sol-gel and sputtering techniques

    International Nuclear Information System (INIS)

    Huang, Z; Donohue, P P; Zhang, Q; Williams, D J; Anthony, C J; Whatmore, R W; Todd, M A

    2003-01-01

    Lead scandium tantalate (PST) thin films for uncooled infrared (IR) detector applications have been deposited by liquid delivery chemical vapour deposition (LDCVD), sputtering and sol-gel techniques. The sol-gel and sputtered films were deposited at low temperature into a non-ferroelectric phase with the required perovskite structure being formed using a high temperature rapid thermal anneal (RTA). In contrast to this, the LDCVD films were deposited at high temperature directly into the perovskite phase but were found to still require a high temperature RTA step to optimize their merit for IR detection. Detailed structural and electrical characterization of the PST films deposited by these different methods have revealed that there is no simple relationship between microstructure and electrical properties. The sol-gel and LDCVD techniques produce thin films with excellent microstructures, as determined by x-ray diffraction analysis and transmission electron microscopy, but inferior electrical properties and relatively low merit figures. By contrast, the sputtered and then rapid thermal annealed films have inferior microstructures, characterized by extensive voiding, but excellent electrical properties and high merit figures

  13. 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.

  14. Aluminum-Scandium Alloys: Material Characterization, Friction Stir Welding, and Compatibility With Hydrogen Peroxide (MSFC Center Director's Discretionary Fund Final Report, Proj. No. 04-14)

    Science.gov (United States)

    Lee, J. A.; Chen, P. S.

    2004-01-01

    This Technical Memorandum describes the development of several high-strength aluminum (Al) alloys that are compatible with hydrogen peroxide (H2O2) propellant for NASA Hypersonic-X (Hyper-X) vehicles fuel tanks and structures. The yield strengths for some of these Al-magnesium-based alloys are more than 3 times stronger than the conventional 5254-H112 Al alloy, while maintaining excellent H2O2 compatibility similar to class 1 5254 alloy. The alloy development strategy is to add scandium, zirconium, and other transitional metals with unique electrochemical properties, which will not act as catalysts, to decompose the highly concentrated 90 percent H2O2. Test coupons are machined from sheet metals for H2O2 long-term exposure testing and mechanical properties testing. In addition, the ability to weld the new alloys using friction stir welding has also been explored. The new high-strength alloys could represent an enabling material technology for Hyper-X vehicles, where flight weight reduction is a critical requirement.

  15. 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.

  16. Assessing the efficiency of aluminium phosphide and arsenic trioxide in controlling the Indian crested porcupine (hystrix indica) in an irrigated forest plantation or Punjab, Pakistan

    International Nuclear Information System (INIS)

    Khan, A.A.

    2010-01-01

    The Indian crested porcupine, Hystrix indica, is widely distributed in the irrigated forests of Punjab, Pakistan and causes serious damage to trees, nursery stocking, field crops and vegetables. Field trials were conducted to determine the efficacy of aluminium phosphide (Phostoxin, 3g tablets) and arsenic trioxide bait (at 2.5g per apple) against the porcupine in a forest plantation. For fumigation with phostoxin, tablets were used at the rate of four, five, six and seven tablets per den. Observations showed that four tablets were ineffective, five and six tablets provided partial control, while seven tablets provided complete control of porcupines. Baiting with arsenic trioxide also resulted in 89 % reduction of the porcupine population occupying the treated dens. (author)

  17. Results from Coupled Optical and Electrical Sentaurus TCAD Models of a Gallium Phosphide on Silicon Electron Carrier Selective Contact Solar Cell

    Energy Technology Data Exchange (ETDEWEB)

    Limpert, Steven; Ghosh, Kunal; Wagner, Hannes; Bowden, Stuart; Honsberg, Christiana; Goodnick, Stephen; Bremner, Stephen; Green, Martin

    2014-06-09

    We report results from coupled optical and electrical Sentaurus TCAD models of a gallium phosphide (GaP) on silicon electron carrier selective contact (CSC) solar cell. Detailed analyses of current and voltage performance are presented for devices having substrate thicknesses of 10 μm, 50 μm, 100 μm and 150 μm, and with GaP/Si interfacial quality ranging from very poor to excellent. Ultimate potential performance was investigated using optical absorption profiles consistent with light trapping schemes of random pyramids with attached and detached rear reflector, and planar with an attached rear reflector. Results indicate Auger-limited open-circuit voltages up to 787 mV and efficiencies up to 26.7% may be possible for front-contacted devices.

  18. Design and fabrication of anti-reflection coating on Gallium Phosphide, Zinc Selenide and Zinc Sulfide substrates for visible and infrared application

    Directory of Open Access Journals (Sweden)

    Mokrý P.

    2013-05-01

    Full Text Available Results of design and fabrication of a dual-band anti-reflection coating on a gallium phosphide (GaP, zinc selenide (ZnSe and zinc sulfide (ZnS substrates are presented. A multilayer stack structure of antireflection coatings made of zinc sulfide and yttrium fluoride (YF3 was theoretically designed for optical bands between 0.8 and 0.9 μm and between 9.5 and 10.5 μm. This stack was designed as efficient for these materials (GaP, ZnS, ZnSe together. Multilayer stack structure was deposited using thermal evaporation method. Theoretically predicted transmittance spectra were compared with transmitted spectra measured on coated substrates. Efficiency of anti-reflection coating is estimated and discrepancies are analyzed and discussed.

  19. Spray pyrolysis synthesis of γ-Al_2O_3 supported metal and metal phosphide catalysts and their activity in the hydrodeoxygenation of a bio-oil model compound

    International Nuclear Information System (INIS)

    Ly, Hoang Vu; Im, Kyungmin; Go, Youngchae; Galiwango, Emmanuel; Kim, Seung-Soo; Kim, Jinsoo; Choi, Jae Hyung; Woo, Hee Chul

    2016-01-01

    Highlights: • Spherical γ-Al_2O_3 supported metal and metal phosphide catalysts were synthesized by spray pyrolysis method. • Hydrodeoxygenation (HDO) of 2-furyl methyl ketone (FMK) was conducted using metal/metal phosphide catalysts. • FMK was converted into 2-allyl furan and methyl cyclohexane. • The highest FMK conversion of 83% was achieved over 10 wt% Ni/γ-Al_2O_3 catalysts at reaction temperature of 400 °C. - Abstract: In this study, spherical γ-Al_2O_3 supported metal and metal phosphide (Ni, Co, Ni_2P and CoP) catalysts were successfully prepared by combining sol-gel and spray pyrolysis methods. First boehmite sol was prepared based on the Yoldas process and then the corresponding metal salts were added to the sol at the desired concentration, followed by spray pyrolysis of the mixed solution. As the well-mixed solution was transformed to spherical γ-Al_2O_3 supported metal and metal phosphide catalysts during spray pyrolysis process, the metal species were uniformly distributed in the mesoporous γ-Al_2O_3 supports. The product catalysts were investigated under different conditions for hydrodeoxygenation of bio-oil model compound, 2-furyl methyl ketone (FMK), which is the main component of the bio-oil product from pyrolysis of Saccharina japonica. Among the investigated catalysts, the 10 wt% Ni/γ-Al_2O_3 catalyst after calcination at 800 °C showed the highest FMK conversion of 83.02% at the reaction temperature of 400 °C. The gas and liquid products were analyzed by gas chromatography (GC) with TCD/FID detectors and GC–MS, respectively, to determine the product compositions.

  20. Synthesis and characterization of low-valence actinide phosphide tellurides and ternary selenium-halide iridium complexes; Synthese und Charakterisierung niedervalenter Actinoidphosphidtelluride und ternaerer Selen-Halogenid-Komplexe des Iridiums

    Energy Technology Data Exchange (ETDEWEB)

    Stolze, Karoline

    2016-04-07

    The thesis on the synthesis and characterization of low-valence actinide phosphide tellurides and ternary selenium-halide iridium complexes includes two parts: a description of the experimental synthesis of UPTe and U2PTe2O and ThPTe and the synthesis of selenium-chloride iridium complexes and selenium-bromide iridium complexes. The characterization included X-ray diffraction and phase studies.

  1. On new ternary equiatomic scandium transition metal aluminum compounds ScTAl with T = Cr, Ru, Ag, Re, Pt, and Au

    Energy Technology Data Exchange (ETDEWEB)

    Radzieowski, Mathis; Janka, Oliver [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Benndorf, Christopher [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Haverkamp, Sandra [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; University of Sao Paulo, Sao Carlos, SP (Brazil). Inst. of Physics

    2016-08-01

    The new equiatomic scandium transition metal aluminides ScTAl for T = Cr, Ru, Ag, Re, Pt, and Au were obtained by arc-melting of the elements followed by subsequent annealing for crystal growth. The samples were studied by powder and single crystal X-ray diffraction. The structures of three compounds were refined from single crystal X-ray diffractometer data: ScCrAl, MgZn{sub 2} type, P6{sub 3}/mmc, a = 525.77(3), c = 858.68(5) pm, R{sub 1} = 0.0188, wR{sub 2} = 0.0485, 204 F{sup 2} values, 13 variables, ScPtAl, TiNiSi type, Pnma, a = 642.83(4), b = 428.96(2), c = 754.54(5) pm, R{sub 1} = 0.0326, wR{sub 2} = 0.0458, 448 F{sup 2} values, 20 variables and ScAuAl, HfRhSn type, P anti 62c, a = 722.88(4), c = 724.15(4) pm, R{sub 1} = 0.0316, wR{sub 2} = 0.0653, 512 F{sup 2} values, 18 variables. Phase pure samples of all compounds were furthermore investigated by magnetic susceptibility measurements, and Pauli-paramagnetism but no superconductivity was observed down to 2.1 K for all of them. The local structural features and disordering phenomena have been characterized by {sup 27}Al and {sup 45}Sc magic angle spinning (MAS) and static NMR spectroscopic investigations.

  2. 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.

  3. Novel elastic, lattice dynamics and thermodynamic properties of metallic single-layer transition metal phosphides: 2H-M 2P (Mo2P, W2P, Nb2P and Ta2P)

    Science.gov (United States)

    Yin, Jiuren; Wu, Bozhao; Wang, Yanggang; Li, Zhimi; Yao, Yuanpeng; Jiang, Yong; Ding, Yanhuai; Xu, Fu; Zhang, Ping

    2018-04-01

    Recently, there has been a surge of interest in the research of two-dimensional (2D) phosphides due to their unique physical properties and wide applications. Transition metal phosphides 2H-M 2Ps (Mo2P, W2P, Nb2P and Ta2P) show considerable catalytic activity and energy storage potential. However, the electronic structure and mechanical properties of 2D 2H-M 2Ps are still unrevealed. Here, first-principles calculations are employed to investigate the lattice dynamics, elasticity and thermodynamic properties of 2H-M 2Ps. Results show that M 2Ps with lower stiffness exhibit remarkable lateral deformation under unidirectional loads. Due to the largest average Grüneisen parameter, single-layer Nb2P has the strongest anharmonic vibrations, resulting in the highest thermal expansion coefficient. The lattice thermal conductivities of Ta2P, W2P and Nb2P contradict classical theory, which would predict a smaller thermal conductivity due to the much heavier atom mass. Moreover, the calculations also demonstrate that the thermal conductivity of Ta2P is the highest as well as the lowest thermal expansion, owing to its weak anharmonic phonon scattering and the lowest average Grüneisen parameter. The insight provided by this study may be useful for future experimental and theoretical studies concerning 2D transition metal phosphide materials.

  4. Solvent extraction of anionic chelate complexes of lanthanum(III), europium(III), lutetium(III), scandium(III), and indium(III) with 2-thenoyltrifluoroacetone as ion-pairs with tetrabutylammonium ions

    International Nuclear Information System (INIS)

    Noro, Junji; Sekine, Tatsuya.

    1992-01-01

    The solvent extraction of lanthanum(III), europium(III), lutetium(III), scandium(III), and indium(III) in 0.1 mol dm -3 sodium nitrate solutions with 2-thenoyltrifluoroacetone (Htta) in the absence and presence of tetrabutylammonium ions (tba + ) into carbon tetrachloride was measured. The extraction of lanthanum(III), europium(III), and lutetium(III) was greatly enhanced by the addition of tba + ; this could be explained in terms of the extraction of a ternary complex, M(tta) 4 - tba + . However, the extractions of scandium(III) and indium(III) were nearly the same when tba + was added. The data were treated on the basis of the formation equilibrium of the ternary complex from the neutral chelate, M(tta) 3 , with the extracted ion-pairs of the reagents, tta - tba + , in the organic phase. It was concluded that the degree of association of M(tta) 3 with the ion-pair, tta - tba + , is greater in the order La(tta) 3 ≅ Eu(tta) 3 > Lu(tta) 3 , or that the stability of the ternary complex in the organic phase is higher in the order La(tta) 4 - tba + ≅ Eu(tta) 4 - tba + > Lu(tta) 4 - tba + . This is similar to those of adduct metal chelates of Htta with tributylphosphate (TBP) in synergistic extraction systems. (author)

  5. Laser ablation synthesis of new gold phosphides using red phosphorus and nanogold as precursors. Laser desorption ionisation time-of-flight mass spectrometry.

    Science.gov (United States)

    Panyala, Nagender Reddy; Peña-Méndez, Eladia María; Havel, Josef

    2012-05-15

    Gold phosphides show unique optical or semiconductor properties and there are extensive high technology applications, e.g. in laser diodes, etc. In spite of the various AuP structures known, the search for new materials is wide. Laser ablation synthesis is a promising screening and synthetic method. Generation of gold phosphides via laser ablation of red phosphorus and nanogold mixtures was studied using laser desorption ionisation time-of-flight mass spectrometry (LDI TOFMS). Gold clusters Au(m)(+) (m = 1 to ~35) were observed with a difference of one gold atom and their intensities were in decreasing order with respect to m. For P(n)(+) (n = 2 to ~111) clusters, the intensities of odd-numbered phosphorus clusters are much higher than those for even-numbered phosphorus clusters. During ablation of P-nanogold mixtures, clusters Au(m)(+) (m = 1-12), P(n)(+) (n = 2-7, 9, 11, 13-33, 35-95 (odd numbers)), AuP(n)(+) (n = 1, 2-88 (even numbers)), Au(2)P(n)(+) (n = 1-7, 14-16, 21-51 (odd numbers)), Au(3)P(n)(+) (n = 1-6, 8, 9, 14), Au(4)P(n)(+) (n = 1-9, 14-16), Au(5)P(n)(+) (n = 1-6, 14, 16), Au(6)P(n)(+) (n = 1-6), Au(7)P(n)(+) (n = 1-7), Au(8)P(n)(+) (n = 1-6, 8), Au(9)P(n)(+) (n = 1-10), Au(10)P(n)(+) (n = 1-8, 15), Au(11)P(n)(+) (n = 1-6), and Au(12)P(n)(+) (n = 1, 2, 4) were detected in positive ion mode. In negative ion mode, Au(m)(-) (m = 1-5), P(n)(-) (n = 2, 3, 5-11, 13-19, 21-35, 39, 41, 47, 49, 55 (odd numbers)), AuP(n)(-) (n = 4-6, 8-26, 30-36 (even numbers), 48), Au(2)P(n)(-) (n = 2-5, 8, 11, 13, 15, 17), A(3) P(n)(-) (n = 6-11, 32), Au(4)P(n)(-) (n = 1, 2, 4, 6, 10), Au(6)P(5)(-), and Au(7)P(8)(-) clusters were observed. In both modes, phosphorus-rich Au(m)P(n) clusters prevailed. The first experimental evidence for formation of AuP(60) and gold-covered phosphorus Au(12)P(n) (n = 1, 2, 4) clusters is given. The new gold phosphides generated might inspire synthesis of

  6. Occupational phosphine gas poisoning at veterinary hospitals from dogs that ingested zinc phosphide--Michigan, Iowa, and Washington, 2006-2011.

    Science.gov (United States)

    2012-04-27

    Zinc phosphide (Zn3P2) is a readily available rodenticide that, on contact with stomach acid and water, produces phosphine (PH3), a highly toxic gas. Household pets that ingest Zn3P2 often will regurgitate, releasing PH3 into the air. Veterinary hospital staff members treating such animals can be poisoned from PH3 exposure. During 2006-2011, CDC's National Institute for Occupational Safety and Health (NIOSH) received reports of PH3 poisonings at four different veterinary hospitals: two in Michigan, one in Iowa, and one in Washington. Each of the four veterinary hospitals had treated a dog that ingested Zn3P2. Among hospital workers, eight poisoning victims were identified, all of whom experienced transient symptoms related to PH3 inhalation. All four dogs recovered fully. Exposure of veterinary staff members to PH3 can be minimized by following phosphine product precautions developed by the American Veterinary Medical Association (AVMA). Exposure of pets, pet owners, and veterinary staff members to PH3 can be minimized by proper storage, handling, and use of Zn3P2 and by using alternative methods for gopher and mole control, such as snap traps.

  7. New Intermetallic Ternary Phosphide Chalcogenide AP2-xXx (A = Zr, Hf; X = S, Se) Superconductors with PbFCl-Type Crystal Structure

    Science.gov (United States)

    Kitô, Hijiri; Yanagi, Yousuke; Ishida, Shigeyuki; Oka, Kunihiko; Gotoh, Yoshito; Fujihisa, Hiroshi; Yoshida, Yoshiyuki; Iyo, Akira; Eisaki, Hiroshi

    2014-07-01

    We have synthesized a series of intermetallic ternary phosphide chalcogenide superconductors, AP2-xXx (A = Zr, Hf; X = S, Se), using the high-pressure synthesis technique. These materials have a PbFCl-type crystal structure (space group P4/nmm) when x is greater than 0.3. The superconducting transition temperature Tc changes systematically with x, yielding dome-like phase diagrams. The maximum Tc is achieved at approximately x = 0.7, at which point the Tc is 6.3 K for ZrP2-xSex (x = 0.75), 5.5 K for HfP2-xSex (x = 0.7), 5.0 K for ZrP2-xSx (x = 0.675), and 4.6 K for Hfp2-xSx (x = 0.5). They are typical type-II superconductors and the upper and lower critical fields are estimated to be 2.92 T at 0 K and 0.021 T at 2 K for ZrP2-xSex (x = 0.75), respectively.

  8. Effects of P/Ni ratio and Ni content on performance of γ-Al{sub 2}O{sub 3}-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang, E-mail: jxchen@tju.edu.cn

    2016-01-01

    Graphical abstract: - Highlights: • The formation of AlPO{sub 4} was unfavorable for that of nickel phosphides. • The phase compositions of nickel phosphide depended on the amount of reduced P. • Catalytic activity was determined by surface Ni site density and catalyst acidity. • HDO pathway was promoted by increasing P/Ni ratio and Ni content. • Nickel phosphide gave much higher carbon yield and lower H{sub 2} consumption than Ni. - Abstract: γ-Al{sub 2}O{sub 3}-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0–2.5) and Ni content (m = 5–15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al{sub 2}O{sub 3} was also studied for comparison. It was found that the formation of AlPO{sub 4} in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni{sub 3}P, Ni{sub 12}P{sub 5} and Ni{sub 2}P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al{sub 2}O{sub 3}, the mNi-Pn catalysts showed much lower activities for decarbonylation, C−C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and

  9. 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.

  10. GeP and (Ge1−xSnx)(P1−yGey) (x≈0.12, y≈0.05): Synthesis, structure, and properties of two-dimensional layered tetrel phosphides

    International Nuclear Information System (INIS)

    Lee, Kathleen; Synnestvedt, Sarah; Bellard, Maverick; Kovnir, Kirill

    2015-01-01

    GeP and Sn-doped GeP were synthesized from elements in bismuth and tin flux, respectively. The layered crystal structures of these compounds were characterized by single crystal X-ray diffraction. Both phosphides crystallize in a GaTe structure type in the monoclinic space group C2/m (No. 12) with GeP: a=15.1948(7) Å, b=3.6337(2) Å, c=9.1941(4) Å, β=101.239(2)°; Ge 0.93(3) P 0.95(1) Sn 0.12(3) : a=15.284(9) Å, b=3.622(2) Å, c=9.207(5) Å, β=101.79(1)°. The crystal structure of GeP consists of 2-dimensional GeP layers held together by weak electron lone pair interactions between the phosphorus atoms that confine the layer. Each layer is built of Ge–Ge dumbbells surrounded by a distorted antiprism of phosphorus atoms. Sn-doped GeP has a similar structural motif, but with a significant degree of disorder emphasized by the splitting of all atomic positions. Resistivity measurements together with quantum-chemical calculations reveal semiconducting behavior for the investigated phosphides. - Graphical abstract: Layered phosphides GeP and Sn-doped GeP were synthesized from elements in bismuth and tin flux, respectively. The crystal structure of GeP consists of 2-dimensional GeP layers held together by weak electron lone pair interactions between the phosphorus atoms that confine the layer. Sn-doped GeP has a similar structural motif with a significant degree of disorder emphasized by the splitting of all atomic positions. Resistivity measurements together with quantum-chemical calculations reveal semiconducting behavior for the investigated phosphides. - Highlights: • GeP crystallizes in a layered crystal structure. • Doping of Sn into GeP causes large structural distortions. • GeP is narrow bandgap semiconductor. • Sn-doped GeP exhibits an order of magnitude higher resistivity due to disorder

  11. A novel boron-rich quaternary scandium borocarbosilicide Sc3.67-xB41.4-y-zC0.67+zSi0.33-w

    International Nuclear Information System (INIS)

    Tanaka, Takaho; Yamamoto, Akiji; Sato, Akira

    2004-01-01

    A novel quaternary scandium borocarbosilicide Sc 3.67-x B 41.4-y-z C 0.67+z Si 0.33-w was found. Single crystallites were obtained as an intergrowth phase in the float-zoned single crystal of Sc 0.83-x B 10.0-y C 0.17+y Si 0.083-z that has a face-centered cubic crystal structure. Single crystal structure analysis revealed that the compound has a hexagonal structure with lattice constants a = b = 1.43055(8) nm and c = 2.37477(13) nm and space group P6-barm2 (No. 187). The crystal composition calculated from the structure analysis for the crystal with x = 0.52, y = 1.42, z = 1.17, and w = 0.02 was ScB 12.3 C 0.58 Si 0.10 and that agreed rather well with the composition of ScB 11.5 C 0.61 Si 0.04 measured by EPMA. In the crystal structure that is a new structure type of boron-rich borides, there are 79 structurally independent atomic sites, 69 boron and/or carbon sites, two silicon sites and eight scandium sites. Boron and carbon form seven structurally independent B 12 icosahedra, one B 9 polyhedron, one B 10 polyhedron, one irregularly shaped B 16 polyhedron in which only 10.7 boron atoms are available because of partial occupancies and 10 bridging sites. All polyhedron units and bridging site atoms interconnect each other forming a three-dimensional boron framework structure. Sc atoms reside in the open spaces in the boron framework structure

  12. Silicon dioxide with a silicon interfacial layer as an insulating gate for highly stable indium phosphide metal-insulator-semiconductor field effect transistors

    Science.gov (United States)

    Kapoor, V. J.; Shokrani, M.

    1991-01-01

    A novel gate insulator consisting of silicon dioxide (SiO2) with a thin silicon (Si) interfacial layer has been investigated for high-power microwave indium phosphide (InP) metal-insulator-semiconductor field effect transistors (MISFETs). The role of the silicon interfacial layer on the chemical nature of the SiO2/Si/InP interface was studied by high-resolution X-ray photoelectron spectroscopy. The results indicated that the silicon interfacial layer reacted with the native oxide at the InP surface, thus producing silicon dioxide, while reducing the native oxide which has been shown to be responsible for the instabilities in InP MISFETs. While a 1.2-V hysteresis was present in the capacitance-voltage (C-V) curve of the MIS capacitors with silicon dioxide, less than 0.1 V hysteresis was observed in the C-V curve of the capacitors with the silicon interfacial layer incorporated in the insulator. InP MISFETs fabricated with the silicon dioxide in combination with the silicon interfacial layer exhibited excellent stability with drain current drift of less than 3 percent in 10,000 sec, as compared to 15-18 percent drift in 10,000 sec for devices without the silicon interfacial layer. High-power microwave InP MISFETs with Si/SiO2 gate insulators resulted in an output power density of 1.75 W/mm gate width at 9.7 GHz, with an associated power gain of 2.5 dB and 24 percent power added efficiency.

  13. Laser ablation synthesis of arsenic-phosphide Asm Pn clusters from As-P mixtures. Laser desorption ionisation with quadrupole ion trap time-of-flight mass spectrometry: The mass spectrometer as a synthesizer.

    Science.gov (United States)

    Kubáček, Pavel; Prokeš, Lubomír; Pamreddy, Annapurna; Peña-Méndez, Eladia María; Conde, José Elias; Alberti, Milan; Havel, Josef

    2018-05-30

    Only a few arsenic phosphides are known. A high potential for the generation of new compounds is offered by Laser Ablation Synthesis (LAS) and when Laser Desorption Ionization (LDI) is coupled with simultaneous Time-Of-Flight Mass Spectrometry (TOFMS), immediate identification of the clusters can be achieved. LAS was used for the generation of arsenic phosphides via laser ablation of phosphorus-arsenic mixtures while quadrupole ion trap time-of-flight mass spectrometry (QIT-TOFMS) was used to acquire the mass spectra. Many new As m P n ± clusters (479 binary and 369 mono-elemental) not yet described in the literature were generated in the gas phase and their stoichiometry determined. The likely structures for some of the observed clusters arbitrary selected (20) were computed by density functional theory (DFT) optimization. LAS is an advantageous approach for the generation of new As m P n clusters, while mass spectrometry was found to be an efficient technique for the determination of cluster stoichiometry. The results achieved might inspire the synthesis of new materials. Copyright © 2018 John Wiley & Sons, Ltd.

  14. Phosphide oxides RE2AuP2O (RE = La, Ce, Pr, Nd): synthesis, structure, chemical bonding, magnetism, and 31P and 139La solid state NMR.

    Science.gov (United States)

    Bartsch, Timo; Wiegand, Thomas; Ren, Jinjun; Eckert, Hellmut; Johrendt, Dirk; Niehaus, Oliver; Eul, Matthias; Pöttgen, Rainer

    2013-02-18

    Polycrystalline samples of the phosphide oxides RE(2)AuP(2)O (RE = La, Ce, Pr, Nd) were obtained from mixtures of the rare earth elements, binary rare earth oxides, gold powder, and red phosphorus in sealed silica tubes. Small single crystals were grown in NaCl/KCl fluxes. The samples were studied by powder X-ray diffraction, and the structures were refined from single crystal diffractometer data: La(2)AuP(2)O type, space group C2/m, a = 1515.2(4), b = 424.63(8), c = 999.2(2) pm, β = 130.90(2)°, wR2 = 0.0410, 1050 F(2) values for Ce(2)AuP(2)O, and a = 1503.6(4), b = 422.77(8), c = 993.0(2) pm, β = 130.88(2)°, wR2 = 0.0401, 1037 F(2) values for Pr(2)AuP(2)O, and a = 1501.87(5), b = 420.85(5), c = 990.3(3) pm, β = 131.12(1)°, wR2 = 0.0944, 1143 F(2) values for Nd(2)AuP(2)O with 38 variables per refinement. The structures are composed of [RE(2)O](4+) polycationic chains of cis-edge-sharing ORE(4/2) tetrahedra and polyanionic strands [AuP(2)](4-), which contain gold in almost trigonal-planar phosphorus coordination by P(3-) and P(2)(4-) entities. The isolated phosphorus atoms and the P(2) pairs in La(2)AuP(2)O could clearly be distinguished by (31)P solid state NMR spectroscopy and assigned on the basis of a double quantum NMR technique. Also, the two crystallographically inequivalent La sites could be distinguished by static (139)La NMR in conjunction with theoretical electric field gradient calculations. Temperature-dependent magnetic susceptibility measurements show diamagnetic behavior for La(2)AuP(2)O. Ce(2)AuP(2)O and Pr(2)AuP(2)O are Curie-Weiss paramagnets with experimental magnetic moments of 2.35 and 3.48 μ(B) per rare earth atom, respectively. Their solid state (31)P MAS NMR spectra are strongly influenced by paramagnetic interactions. Ce(2)AuP(2)O orders antiferromagnetically at 13.1(5) K and shows a metamagnetic transition at 11.5 kOe. Pr(2)AuP(2)O orders ferromagnetically at 7.0 K.

  15. 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.

  16. Bimetallic Cobalt-Based Phosphide Zeolitic Imidazolate Framework: CoP x Phase-Dependent Electrical Conductivity and Hydrogen Atom Adsorption Energy for Efficient Overall Water Splitting

    Energy Technology Data Exchange (ETDEWEB)

    Song, Junhua [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Zhu, Chengzhou [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Xu, Bo Z. [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Fu, Shaofang [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Engelhard, Mark H. [Pacific Northwest National Laboratory, Richland WA 99352 USA; Ye, Ranfeng [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Du, Dan [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Beckman, Scott P. [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Lin, Yuehe [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Pacific Northwest National Laboratory, Richland WA 99352 USA

    2016-10-25

    Cobalt-based bimetallic phosphide encapsulated in carbonized zeolitic imadazolate frameworks has been successfully synthesized and showed excellent activities toward both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Density functional theory calculation and electrochemical measurements reveal that the electrical conductivity and electrochemical activity are closely associated with the Co2P/CoP mixed phase behaviors upon Cu metal doping. This relationship is found to be the decisive factor for enhanced electrocatalytic performance. Moreover, the precise control of Cu content in Co-host lattice effectively alters the Gibbs free energy for H* adsorption, which is favorable for facilitating reaction kinetics. Impressively, an optimized performance has been achieved with mild Cu doping in Cu0.3Co2.7P/nitrogen-doped carbon (NC) which exhibits an ultralow overpotential of 0.19 V at 10 mA cm–2 and satisfying stability for OER. Cu0.3Co2.7P/NC also shows excellent HER activity, affording a current density of 10 mA cm–2 at a low overpotential of 0.22 V. In addition, a homemade electrolyzer with Cu0.3Co2.7P/NC paired electrodes shows 60% larger current density than Pt/ RuO2 couple at 1.74 V, along with negligible catalytic deactivation after 50 h operation. The manipulation of electronic structure by controlled incorporation of second metal sheds light on understanding and synthesizing bimetallic transition metal phosphides for electrolysis-based energy conversion.

  17. Electrostatically driven resonance energy transfer in ?cationic? biocompatible indium phosphide quantum dots? ?Electronic supplementary information (ESI) available: Detailed experimental methods, the synthesis and characterization of QDs, bioimaging, stability studies, control experiments, and the calculation of various parameters involved in the resonance energy transfer process etc. See DOI: 10.1039/c7sc00592j Click here for additional data file.

    OpenAIRE

    Devatha, Gayathri; Roy, Soumendu; Rao, Anish; Mallick, Abhik; Basu, Sudipta; Pillai, Pramod P.

    2017-01-01

    Indium Phosphide Quantum Dots (InP QDs) have emerged as an alternative to toxic metal ion based QDs in nanobiotechnology. The ability to generate cationic surface charge, without compromising stability and biocompatibility, is essential in realizing the full potential of InP QDs in biological applications. We have addressed this challenge by developing a place exchange protocol for the preparation of cationic InP/ZnS QDs. The quaternary ammonium group provides the much required permanent posi...

  18. Molecular Nickel Phosphide Carbonyl Nanoclusters: Synthesis, Structure, and Electrochemistry of [Ni11P(CO)18]3- and [H6-nNi31P4(CO)39]n- (n = 4 and 5).

    Science.gov (United States)

    Capacci, Chiara; Ciabatti, Iacopo; Femoni, Cristina; Iapalucci, Maria Carmela; Funaioli, Tiziana; Zacchini, Stefano; Zanotti, Valerio

    2018-02-05

    The reaction of [NEt 4 ] 2 [Ni 6 (CO) 12 ] in thf with 0.5 equiv of PCl 3 affords the monophosphide [Ni 11 P(CO) 18 ] 3- that in turn further reacts with PCl 3 resulting in the tetra-phosphide carbonyl cluster [HNi 31 P 4 (CO) 39 ] 5- . Alternatively, the latter can be obtained from the reaction of [NEt 4 ] 2 [Ni 6 (CO) 12 ] in thf with 0.8-0.9 equiv of PCl 3 . The [HNi 31 P 4 (CO) 39 ] 5- penta-anion is reversibly protonated by strong acids leading to the [H 2 Ni 31 P 4 (CO) 39 ] 4- tetra-anion, whereas deprotonation affords the [Ni 31 P 4 (CO) 39 ] 6- hexa-anion. The latter is reduced with Na/naphthalene yielding the [Ni 31 P 4 (CO) 39 ] 7- hepta-anion. In order to shed light on the polyhydride nature and redox behavior of these clusters, electrochemical and spectroelectrochemical studies were carried out on [Ni 11 P(CO) 18 ] 3- , [HNi 31 P 4 (CO) 39 ] 5- , and [H 2 Ni 31 P 4 (CO) 39 ] 4- . The reversible formation of the stable [Ni 11 P(CO) 18 ] 4- tetra-anion is demonstrated through the spectroelectrochemical investigation of [Ni 11 P(CO) 18 ] 3- . The redox changes of [HNi 31 P 4 (CO) 39 ] 5- show features of chemical reversibility and the vibrational spectra in the ν CO region of the nine redox states of the cluster [HNi 31 P 4 (CO) 39 ] n- (n = 3-11) are reported. The spectroelectrochemical investigation of [H 2 Ni 31 P 4 (CO) 39 ] 4- revealed the presence of three chemically reversible reduction processes, and the IR spectra of [H 2 Ni 31 P 4 (CO) 39 ] n- (n = 4-7) have been recorded. The different spectroelectrochemical behavior of [HNi 31 P 4 (CO) 39 ] 5- and [H 2 Ni 31 P 4 (CO) 39 ] 4- support their formulations as polyhydrides. Unfortunately, all the attempts to directly confirm their poly hydrido nature by 1 H NMR spectroscopy failed, as previously found for related large metal carbonyl clusters. Thus, the presence and number of hydride ligands have been based on the observed protonation/deprotonation reactions and the spectroelectrochemical

  19. Phase equilibria in the Mo-Fe-P system at 800 °C and structure of ternary phosphide (Mo(1-x)Fe(x))3P (0.10 ≤ x ≤ 0.15).

    Science.gov (United States)

    Oliynyk, Anton O; Lomnytska, Yaroslava F; Dzevenko, Mariya V; Stoyko, Stanislav S; Mar, Arthur

    2013-01-18

    Construction of the isothermal section in the metal-rich portion (ternary phases: (Mo(1-x)Fe(x))(2)P (x = 0.30-0.82) and (Mo(1-x)Fe(x))(3)P (x = 0.10-0.15). The occurrence of a Co(2)Si-type ternary phase (Mo(1-x)Fe(x))(2)P, which straddles the equiatomic composition MoFeP, is common to other ternary transition-metal phosphide systems. However, the ternary phase (Mo(1-x)Fe(x))(3)P is unusual because it is distinct from the binary phase Mo(3)P, notwithstanding their similar compositions and structures. The relationship has been clarified through single-crystal X-ray diffraction studies on Mo(3)P (α-V(3)S-type, space group I42m, a = 9.7925(11) Å, c = 4.8246(6) Å) and (Mo(0.85)Fe(0.15))(3)P (Ni(3)P-type, space group I4, a = 9.6982(8) Å, c = 4.7590(4) Å) at -100 °C. Representation in terms of nets containing fused triangles provides a pathway to transform these closely related structures through twisting. Band structure calculations support the adoption of these structure types and the site preference of Fe atoms. Electrical resistivity measurements on (Mo(0.85)Fe(0.15))(3)P reveal metallic behavior but no superconducting transition.

  20. Controllable synthesis of a monophase nickel phosphide/carbon (Ni{sub 5}P{sub 4}/C) composite electrode via wet-chemistry and a solid-state reaction for the anode in lithium secondary batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yi; Tu, Jiang-Ping; Xiong, Qin-Qin; Mai, Yong-Jin; Zhang, Jun; Qiao, Yan-Qiang; Wang, Xiu-Li; Gu, Chang-Dong [State Key Laboratory of Silicon Materials and Department of Materials, Science and Engineering, Zhejiang University, Hangzhou, 310027 (China); Xiang, Jia-Yuan [Narada Power Source Co. Ltd., Hangzhou, 311105 (China); Mao, Scott X. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2012-09-25

    A monophase nickel phosphide/carbon (Ni{sub 5}P{sub 4}/C) composite with a thin carbon shell is controllably synthesized via the two-step strategy of a wet-chemistry reaction and a solid-state reaction. In this fabrication, the further diffusion of phosphorus atoms in the carbon shell during the solid-state reaction can be responsible for a chemical transformation from a binary phase of Ni{sub 5}P{sub 4}-Ni{sub 2}P to monophase Ni{sub 5}P{sub 4}. Galvanostatic charge-discharge measurements indicate that the Ni{sub 5}P{sub 4}/C composite exhibits a superior, high rate capacity and good cycling stability. About 76.6% of the second capacity (644.1 mA h g{sup -1}) can be retained after 50 cycles at a 0.1 C rate. At a high rate of 3 C, the specific capacity of Ni{sub 5}P{sub 4}/C is still as high as 357.1 mA h g{sup -1}. Importantly, the amorphous carbon shell can enhance the conductivity of the composite and suppress the aggregation of the active particles, leading to their structure stability and reversibility during cycling. As is confirmed from X-ray-diffraction analysis, no evident microstructural changes occur upon cycling. These results reveal that highly crystalline Ni{sub 5}P{sub 4}/C is one of the most promising anode materials for lithium-ion batteries. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Atomic Transition Probabilities Scandium through Manganese

    International Nuclear Information System (INIS)

    Martin, G.A.; Fuhr, J.R.; Wiese, W.L.

    1988-01-01

    Atomic transition probabilities for about 8,800 spectral lines of five iron-group elements, Sc(Z = 21) to Mn(Z = 25), are critically compiled, based on all available literature sources. The data are presented in separate tables for each element and stage of ionization and are further subdivided into allowed (i.e., electric dipole-E1) and forbidden (magnetic dipole-M1, electric quadrupole-E2, and magnetic quadrupole-M2) transitions. Within each data table the spectral lines are grouped into multiplets, which are in turn arranged according to parent configurations, transition arrays, and ascending quantum numbers. For each line the transition probability for spontaneous emission and the line strength are given, along with the spectroscopic designation, the wavelength, the statistical weights, and the energy levels of the upper and lower states. For allowed lines the absorption oscillator strength is listed, while for forbidden transitions the type of transition is identified (M1, E2, etc.). In addition, the estimated accuracy and the source are indicated. In short introductions, which precede the tables for each ion, the main justifications for the choice of the adopted data and for the accuracy rating are discussed. A general introduction contains a discussion of our method of evaluation and the principal criteria for our judgements

  2. Fast neutron scattering near shell closures: Scandium

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.

    1992-08-01

    Neutron differential elastic- and inelastic-scattering cross sections are measured from ∼ 1.5 to 10 MeV with sufficient detail to define the energy-averaged behavior of the scattering processes. Neutrons corresponding to excitations of 465 ± 23, 737 ± 20, 1017 ± 34, 1251 ± 20, 1432 ± 23 and 1692 ± 25 keV are observed. It is shown that the observables, including the absorption cross section, are reasonably described with a conventional optical-statistical model having energy-dependent geometric parameters. These energy dependencies are alleviated when the model is extended to include the contributions of the dispersion relationship. The model parameters are conventional, with no indication of anomalous behavior of the neutron interaction with 45 Sc, five nucleons from the doubly closed shell at 40 Ca

  3. On interaction of zirconium isopropylate with scandium and lanthanum isopropylates. Alkoxozirconates of the scandium subgroup

    International Nuclear Information System (INIS)

    Turova, N.Ya.; Kozlova, N.I.

    1982-01-01

    The solubility in the Zr(OR) 4 -Sc(OR) 3 -THF and Zr(OR) 4 -La(OR) 3 -ROH (R=iso-Pr) at 20 deg was studied. It was ascertained that complex formation did not occur in the first system and LaZr 3 (OR) 15 x3ROH were present in the second one. Complex properties were studied by the methods of IR, PMR spectroscopy, mass-spectrometric and preparative methods. A structure with octahedric coordination of M 3 and Zr atoms was supposed for M 3 Zr 3 (OR) 15 x3L (M=Y, La). Regularities in the change of Sc, Y, La alkoxozirconates were established

  4. Cleavage Luminescence from Cleaved Indium Phosphide

    International Nuclear Information System (INIS)

    Dong-Guang, Li

    2008-01-01

    We outline the experiments performed to gain further information about the structure and properties of cleaved InP surfaces. The experiments involved detecting the luminescence produced after cleaving thin InP plates within a high vacuum, by a process of converting the luminescence to an electrical signal which could be amplified and measured accurately. The experimental results show that the detected luminescence durations from cleaved InP are usually only about 10μs. It is believed that this time represents the time of travel of the crack with the actual recombination time being much shorter. Strong signals could also be picked up from cleaved InP in air

  5. Radiative recombination in doped indium phosphide crystals

    International Nuclear Information System (INIS)

    Negreskul, V.V.; Russu, E.V.; Radautsan, S.I.; Cheban, A.G.; AN Moldavskoj SSR, Kishinev. Inst. Prikladnoj Fiziki)

    1975-01-01

    Photoluminiscence spectra of nondoped n-InP and their change upon doping with silicon, cadmium, zinc and copper impurities were studied. The shortest wave band at 1.41 eV is connected with radiative electron transition from a shallow donor level (probably silicon) to valent zone, while the band with maximum at 1.37 - 1.39 eV is due to radiative electron transition to an acceptor level whose energy depends upon the nature and concentration of impurity implanted. The luminescence of Light-doped p-InP crystals enables to estimate the ionization energies of acceptor levels in cadmium (Esub(a)=0.043 eV) and zinc (Esub(a)=0.027 eV). Energies of acceptor levels (0.22 and 0.40 eV) due to copper impurity are determined. Intensity of edge emission in the specimens light-doped with silicon is higher than in the nondoped n-InP crystals

  6. Optical studies of vanadium in gallium phosphide

    International Nuclear Information System (INIS)

    Ulrici, W.; Friedland, K.

    1987-01-01

    The results of optical absorption, luminescence, luminescence excitation, and temperature-dependent Hall-effect measurements on semi-insulating n-type GaP:V and n-conducting GaP:V are reported. The V Ga 2+ V Ga 3+ acceptor level is found at E c - 0.58 eV. Absorptions due to photoionization transitions from and into this level can be identified. The absorption bands due to the transitions 3 A 2 → 3 T 1 (F) and → 3 T 1 (P) of V Ga 3+ are measured, both absorptions include three zero-phonon lines as well as phonon replica. At low temperatures the photoinduced rechargings V Ga 3+ V Ga 3+ are investigated and interpreted in terms of the three charge states of V Ga and the excitation of electrons from the P Ga 4+ P 4 anti-site centre. (author)

  7. Ternary scandium-rich indides Sc{sub 50}T{sub 13}In{sub 3} and Sc{sub 50}Rh{sub 13}In{sub 3}O{sub y} (T = Rh, Ir; y {approx} 8) - synthesis and crystal structure

    Energy Technology Data Exchange (ETDEWEB)

    Zaremba, R.; Poettgen, R. [Inst. fuer Anorganische und Analytische Chemie, Univ. Muenster (Germany)

    2007-12-15

    New intermetallic compounds Sc{sub 50}Rh{sub 13.3}In{sub 2.7} and Sc{sub 50}Ir{sub 13.6}In{sub 2.4} and the suboxides Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8} and Sc{sub 49.2}Rh{sub 13.7}In{sub 2.8}O{sub 8.0} were synthesized from the elements or with Sc{sub 2}O{sub 3} as an oxygen source, respectively, in sealed tantalum tubes in a water-cooled sample chamber of an induction furnace. They crystallize with a new cubic structure type, space group F m anti 3, a = 1772.5(6) pm, wR2 = 0.032, 1111 F{sup 2} values, 34 variables for Sc{sub 50}Rh{sub 13.3}In{sub 2.7}, a = 1766.5(6) pm, wR2 = 0.041, 745 F{sup 2} values, 34 variables for Sc{sub 50}Ir{sub 13.6}In{sub 2.4}, a = 1764.4(2) pm, wR2 = 0.044, 640 F{sup 2} values, 41 variables for Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8}, and a = 1761.5(6) pm, wR2 = 0.054, 740 F{sup 2} values, 42 variables for Sc{sub 49.2}Rh{sub 13.7}In{sub 2.8}O{sub 8.0}. The main structural motifs are rhodium-centered indium cubes in an fcc like arrangement in which the octahedral and tetrahedral voids are filled by In2Sc{sub 12} and In1Sc{sub 12} icosahedra, respectively, resembling a Li{sub 3}Bi-like structure. The Rh1 (Ir1) and Sc4 atoms lie between these polyhedral units. The oxygen atoms partially fill Sc{sub 6} octahedra in Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8} and Sc{sub 49.2}Rh{sub 13.7}In{sub 2.8}O{sub 8.0} with Sc-O distances of 214 - 230 pm. These octahedra are condensed via common edges and faces, encapsulating the In2Sc{sub 12} icosahedra. Due to the high scandium content one observes strong Sc-Sc bonding with Sc-Sc distances ranging from 303 to 362 pm in Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8}. The shortest distances occur for Sc-Rh (267 - 295 pm). The crystal chemical relationship with the Li{sub 3}Bi-related suboxide Ti{sub 12}Sn{sub 3}O{sub 10} is discussed. (orig.)

  8. The spectrum of singly ionized scandium, Sc II

    International Nuclear Information System (INIS)

    Johansson, S.; Litzen, U.

    1980-01-01

    The Sc II spectrum, emitted from a pulsed hollow-cathode discharge, has been studied in the region 1100-11 000 A, where 777 lines have been classified. 168 levels are now known, belonging to configurations of the types 3dnl, 4snl and 4p 2 . Parametric studies have been made for a number of configurations. A determination of the ionization limit from the configurations 3d4f, 5f and 5g gives the value 103 237.1+-2 cm -1 . (Auth.)

  9. Polar and chemical domain structures of lead scandium tantalate (PST)

    International Nuclear Information System (INIS)

    Peng, J.L.; Bursill, L.A.

    1993-01-01

    The local structure of chemical and polar domains and domain walls is determined directly by atomic resolution high-resolution electron microscopy. Thus the Pb, Ta and Sc atomic positions may be located in the images of very thin crystals. Furthermore the Pb cation displacements away from the ideal perovskite A-site have been measured directly for the first time. Local variations in polarization direction may be mapped directly off the images, provided certain electron optical conditions are met. The results are relevant to recent theories of polar-glass behaviour in relaxor-type complex oxide functional ceramics. 17 refs., 9 figs

  10. Hydrogen-isotope motion in scandium studied by ultrasonic measurements

    International Nuclear Information System (INIS)

    Leisure, R.G.; Schwarz, R.B.; Migliori, A.; Torgeson, D.R.; Svare, I.

    1993-01-01

    Resonant ultrasound spectroscopy has been used to investigate ultrasonic attenuation in single crystals of Sc, ScH 0.25 , and ScD 0.18 over the temperature range of 10--300 K for frequencies near 1 MHz. Ultrasonic-attenuation peaks were observed in the samples containing H or D with the maximum attenuation occurring near 25 K for ScH 0.25 and near 50 K for ScD 0.18 . The general features of the data suggest that the motion reflected in the ultrasonic attenuation is closely related to the low-temperature motion seen in nulcear-magnetic-resonance spin-lattice-relaxation measurements. The ultrasonic results were fit with a two-level-system (TLS) model involving tunneling between highly asymmetric sites. The relaxation of the TLS was found to consist of two parts: a weakly temperature-dependent part, probably due to coupling to electrons; and a much more strongly temperature-dependent part, attributed to multiple-phonon processes. The strongly temperature-dependent part was almost two orders of magnitude faster in ScH 0.25 than in ScD 0.18 , in accordance with the idea that tunneling is involved in the motion. Surprisingly, the weakly temperature-dependent part was found to be about the same for the two isotopes. The asymmetries primarily responsible for coupling the TLS to the ultrasound are attributed to interactions between hydrogen ions that lie on adjacent c axes. The results are consistent with an isotope-independent strength for the coupling of the TLS to the ultrasound

  11. Radiopharmaceuticals based on the scandium or rhodium radionuclides

    International Nuclear Information System (INIS)

    Majkowska, A.; Pruszynski, M.; Bilewicz, A.

    2006-01-01

    Radionuclides 103m Rh, 105 Rh emitting β-radiation or 47 Sc (Auger electrons emitter) are suitable for treatment small tumors spread over the human tissues. Presented communication describes preliminary results obtained in the Institute of Nuclear Chemistry and Technology, Warsaw (Poland) in the field of obtaining new complexes containing the aforementioned radionuclides. The radionuclides can be produced in the laboratory scale from simple and cheap generators. 103m Rh and 105 Rh cations were complexed with the thioetheric ligand (1,5,9,13-tetrathiacyclahexadecane-3,11-diole) and in the future, after funcionalization with certain biomolecules, are promising radiopharmaceuticals. 47 Sc cation was complexes by one from the following tri- or tetraaza macoryclic ligands: 1,4,7,10-triazacyclononane-1,4,7-triacetic acid (NOTA), 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (DO2A) or 1,4,7,10-triazacyclononane-1,4,7-triacetic acid (NOTA), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). Composition and the stability constants of the complexes were determined

  12. Scandium doped Strontium Titanate Ceramics: Structure, Microstructure, and Dielectric Properties

    Directory of Open Access Journals (Sweden)

    Tkach, Alexander

    2008-08-01

    Full Text Available Sc-doped strontium titanate (ST ceramics were synthesised by solid state reaction, according to the composition Sr1-1.5xScxTiO3 with x = 0-0.01. Structural properties and microstructure development was examined by XRD and SEM. The dielectric properties were evaluated as a function of the temperature and frequency in the radio frequency range. Lattice parameter, density and grain size, were found to decrease slightly with increasing Sc content. The dielectric permittivity and losses decrease also. Sc-doping has only a weak effect on the quantum paraelectric behaviour of ST and no dielectric anomaly was observed, what is probably related to the limited solubility of Sc on the Sr site of the perovskite lattice of ST.

    Se sintetizaron materiales cerámicos de titanato de estroncio dopado con escandio mediante reacción en estado sólido De acuerdo a la composición Sr1-1.5xScxTiO3 con x= 0-0.1. Las propiedades estructurales y el desarrollo microestructural se estudiaron mediante XRD y SEM. La propiedades dieléctricas se estudiaron como función de la temperatura y de la frecuencia en el rango de la frecuencias de radio. Se observó que los parámetros de red, la densidad y el tamaño del grano disminuyen ligeramente con el contenido en Sc. La permitividad dieléctrica y las perdidas también disminuyen. El dopado con Sc tiene un efecto muy ligero sobre el comportamiento paraeléctrico cuántico del titanato de estroncio y no se observó anomalías dioeléctricas , lo que está probablemente relacionado con la baja solubilidad del Sc en posiciones del Sr en la estructura tipo perovskita del titanato de estroncio.

  13. Gadolinium scandium germanide, Gd2Sc3Ge4

    Directory of Open Access Journals (Sweden)

    Sumohan Misra

    2009-04-01

    Full Text Available Gd2Sc3Ge4 adopts the orthorhombic Pu5Rh4-type structure. The crystal structure contains six sites in the asymmetric unit: two sites are statistically occupied by rare-earth atoms with Gd:Sc ratios of 0.967 (4:0.033 (4 and 0.031 (3:0.969 (3, one site (.m. symmetry is occupied by Sc atoms, and three distinct sites (two of which with .m. symmetry are occupied by Ge atoms. The rare-earth atoms form two-dimensional slabs with Ge atoms occupying the trigonal-prismatic voids.

  14. A scandium calibration source for the SNO+ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Boeltzig, Axel; Barros, Nuno; Krueger, Felix; Krosigk, Belina von; Lozza, Valentina; Neumann, Laura; Petzoldt, Johannes; Soerensen, Arnd; Zuber, Kai [TU Dresden (Germany)

    2013-07-01

    The SNO+ experiment is the successor of SNO (Sudbury Neutrino Observatory), for which the detector will be filled with liquid scintillator. Located 2 km underground (equivalent to a shielding of about 6 km of water) in a mine near Sudbury, Canada, SNO+ will be a low-background experiment studying different aspects of neutrinos. The SNO+ detector calibration is scheduled to begin in mid-2013 with a water-filled detector and in 2014 filled with liquid scintillator. One of the sources designated for this calibration will use the γ rays following the beta decay of {sup 48}Sc. The sum of their energies is 3.333 MeV for the main decay branch, which is close to Q=3.371 MeV for the neutrino-less double beta decay of {sup 150}Nd that SNO+ plans to investigate. Due to the {sup 48}Sc half-life of 43.67 h, the source has to be produced shortly before the calibration via (n,p) reactions on {sup 48}Ti. Safety, radiopurity and cleanliness are further important issues for its application. The current status of the source development will be presented.

  15. Coordination compounds of scandium with dimethylsulfoxide and dimethylformamide

    International Nuclear Information System (INIS)

    Cherkasova, T.G.; Tatarinova, Eh.S.; Tryasunov, B.G.

    1991-01-01

    The possibility to prepare crystal coordination compounds in the systems ScCl 3 -K 3 [Cr(SCN) 6 ]-DMSO (DMFA) was studied. The complexes isolated were investigated by physicochemical methods. Their composition, behaviour in chemically agressive media, density, electric conductivity of solutions and magnetic susceptibility at 298 K were ascertained

  16. The solidification behavior of dilute aluminium-scandium alloys

    International Nuclear Information System (INIS)

    Norman, A.F.; Prangnell, P.B.; McEwen, R.S.

    1998-01-01

    The solidification behavior of dilute Sc containing Al alloys has been investigated. In binary Al-Sc alloys, Sc additions greater than the eutectic composition (0.55 wt%) were found to produce a remarkable refinement in the grain size of aluminum castings, of two orders of magnitude, due to the formation of the primary Al 3 Sc intermetallic phase during solidification. The refinement in grain size only occurred in hypereutectic compositions and was shown to be far greater than can be achieved by conventional Al grain refiners. Grain refinement by the addition of Sc is accompanied by a change in growth morphology from dendritic, in the large unrefined grains, to fine spherical grains with a divorced eutectic appearing on the grain boundaries in the refined castings. Similar levels of refinement were observed in Al-Sc-Zr and Al-Cu-Sc alloys. In the latter, a change in the segregation behavior of Cu was observed, from a strongly interdendritic segregation pattern to a more homogeneous distribution. The supersaturated Al-Sc solid solution can decompose via a discontinuous precipitation reaction to form coherent rod-like precipitates of the L1 2 Al 3 Sc phase

  17. Oxidation of scandium thin films on tungsten surface

    International Nuclear Information System (INIS)

    Gorodetskij, D.A.; Martynyuk, A.V.

    1988-01-01

    Presence of Sc on the surface of W in amounts larger than a monolayer coverage leads to a decrease of the work function at the initial oxidation stage, which is attributed to oxygen implantation into the surface layer of the metal. A subsequent oxidation is followed by the formation on the surface of a thin oxide layer and an increase of the work function. An increase of the amount of Sc deposited on the surface before the oxidation decreases the work function of the obtained oxide from 5.8 (clean W surface) down to 3.3 eV (thick Sc layer on W)

  18. Electrostatically driven resonance energy transfer in “cationic” biocompatible indium phosphide quantum dots† †Electronic supplementary information (ESI) available: Detailed experimental methods, the synthesis and characterization of QDs, bioimaging, stability studies, control experiments, and the calculation of various parameters involved in the resonance energy transfer process etc. See DOI: 10.1039/c7sc00592j Click here for additional data file.

    Science.gov (United States)

    Devatha, Gayathri; Roy, Soumendu; Rao, Anish; Mallick, Abhik; Basu, Sudipta

    2017-01-01

    Indium Phosphide Quantum Dots (InP QDs) have emerged as an alternative to toxic metal ion based QDs in nanobiotechnology. The ability to generate cationic surface charge, without compromising stability and biocompatibility, is essential in realizing the full potential of InP QDs in biological applications. We have addressed this challenge by developing a place exchange protocol for the preparation of cationic InP/ZnS QDs. The quaternary ammonium group provides the much required permanent positive charge and stability to InP/ZnS QDs in biofluids. The two important properties of QDs, namely bioimaging and light induced resonance energy transfer, are successfully demonstrated in cationic InP/ZnS QDs. The low cytotoxicity and stable photoluminescence of cationic InP/ZnS QDs inside cells make them ideal candidates as optical probes for cellular imaging. An efficient resonance energy transfer (E ∼ 60%) is observed, under physiological conditions, between the cationic InP/ZnS QD donor and anionic dye acceptor. A large bimolecular quenching constant along with a linear Stern–Volmer plot confirms the formation of a strong ground state complex between the cationic InP/ZnS QDs and the anionic dye. Control experiments prove the role of electrostatic attraction in driving the light induced interactions, which can rightfully form the basis for future nano-bio studies between cationic InP/ZnS QDs and anionic biomolecules. PMID:28626557

  19. Femtosecond Nonlinearities in Indium Gallium Arsenic Phosphide Diode Lasers

    Science.gov (United States)

    Hall, Katherine Lavin

    Semiconductor optical amplifiers are receiving increasing attention for possible applications to broadband optical communication and switching systems. In this thesis we report the results of an extensive experimental study of the ultrafast gain and refractive index nonlinearities in 1.5 μm InGaAsP laser diode amplifiers. The temporal resolution afforded by the femtosecond optical pulses used in these experiments allows us to study carrier interactions with other carriers as well as carrier interactions with the lattice. The 100-200 fs optical pulses used in the pump -probe experiments are generated by an Additive Pulse Modelocked color center laser. The measured group velocity dispersion in the diodes ranged from -0.6 to -0.95 mu m^{-1 }. Differences in the group velocity for TE - and TM-polarized pulses suggested that cross-polarized pump-probe pulses walk off from each other in the diode. This walk-off can diminish the time resolution of some experiments. A novel heterodyne pump-probe technique was developed to distinguish collinear, copolarized, pump and probe pulses that were nominally at the same wavelength. Comparing cross-polarized and copolarized pump-probe results yielded new information about the physical mechanisms responsible for nonlinear gain in the diodes. We observed a gain compression across the entire bandwidth of the diode, associated with carrier heating. The hot carrier distribution cooled back to the lattice temperature with a 0.6 to 1.0 ps time constant, depending on the device structure. In addition, we observed a 0.1 to 0.25 ps delay in onset of carrier heating. Large gain compression due to two photon absorption was also observed. A small portion of the nonlinear gain is attributed to spectral hole burning. Pulsewidth-dependent output saturation energies were explained by a rate equation model that included the effect of carrier heating. Measurements of pump-induced probe phase changes revealed index nonlinearities due to delayed carrier heating and an instantaneous electronic, or virtual process. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617 -253-5668; Fax 617-253-1690.).

  20. Optical and photocatalytic properties of indium phosphide nanoneedles and nanotubes

    DEFF Research Database (Denmark)

    Yu, Yanlong; Yu, Cuiyan; Xu, Tao

    2017-01-01

    , and Ultraviolet-visible (UV–vis) spectroscopy. The room temperature photoluminescence (PL) measurements showed that the InP nanoneedles and nanotubes possessed a pronounced blue shift in contrast to the bulk counterpart, which was ascribed to the crystalline defects effect. Moreover, the InP nanotubes exhibited...

  1. Effect of Aluminium Phosphide Poisoning on Blood Cortisol Level

    Directory of Open Access Journals (Sweden)

    Fariba Farnaghi

    2013-02-01

    Full Text Available Background: Acute intoxication with ALP is extremely lethal. The present study was conducted to determine the range of serum cortisol levels in ALP poisoning and its correlation with patient outcome. Methods: This study was carried out on patients who were intoxicated with ALP. Their demographic data and pertinent findings in their history and physical examination were recorded at the time of arrival and also when shock and severe metabolic acidosis emerged. 5cc blood was taken from the patients to measure blood cortisol level, when shock and severe metabolic acidosis developed. Blood cortisol level analysis was performed using ELISA method. Data analysis was done using SPSS software version 16.0. Results: The average ingested dose was 1.98+1.79 tablets each containing 3 grams of ALP. Overall, 77% of the patients presented tachycardia and hypotension. Blood cortisol level less than 15 µg/dl, 15-33 µg/dl, and more than 34 µg/dl were regarded as adrenal insufficiency, critical illness-related corticosteroid insufficiency, and adequate adrenal response, respectively. Eventually, 3 patients fell within the first category, 24 patients matched with the second category, and 3 patients corresponded to the last category. Conclusion: Blood cortisol concentration is satisfactory only in 10% of the patients. In majority of the patients although it is not apparently low, it has not shown the expected rise comparable to the shock and stress state of such patients. It defines a role for corticosteroids therapy in management of ALP poisoning, particularly if it does not respond to conventional treatments.

  2. Indium phosphide (InP) for optical interconnects

    NARCIS (Netherlands)

    Lebby, M.; Ristic, S.; Calabretta, N.; Stabile, R.; Tekin, T.; Pitwon, R.; Håkansson, A.; Pleros, N.

    2016-01-01

    We present InP as the incumbent technology for data center transceiver and switching optics. We review the most popular InP monolithic integration approaches in light of photonic integration being recognized as an increasingly important technology for data center optics. We present Multi-Guide

  3. Measurement of surface recombination velocity on heavily doped indium phosphide

    International Nuclear Information System (INIS)

    Jenkins, P.; Ghalla-Goradia, M.; Faur, M.; Bailey, S.

    1990-01-01

    The controversy surrounding the published low values of surface recombination velocity (SRV) in n-InP, solidified in recent years when modeling of existing n/p InP solar cells revealed that the front surface SRV had to be higher than 1 x 10 6 cm/sec in order to justify the poor blue response that is characteristic of all n/p InP solar cells. In this paper, SRV on heavily doped (>10 18 cm -3 )n-type and p-type InP is measured as a function of surface treatment. For the limited range of substrates and surface treatments studied, SRV and surface stability depend strongly on the surface treatment. SRVs of ∼10 5 cm/sec in both p-type and n-type InP are obtainable, but in n-type the low SRV surfaces were unstable, and the only stable surfaces on n-type had SRVs of >10 6 cm/sec

  4. Room temperature particle detectors based on indium phosphide

    Czech Academy of Sciences Publication Activity Database

    Yatskiv, Roman; Grym, Jan; Žďánský, Karel; Pekárek, Ladislav

    2010-01-01

    Roč. 612, č. 2 (2010), s. 334-337 ISSN 0168-9002 R&D Projects: GA AV ČR KJB200670901; GA AV ČR(CZ) KAN401220801; GA ČR(CZ) GP102/08/P617 Institutional research plan: CEZ:AV0Z20670512 Keywords : Particle detector * Semi-insulating InP * High purity InP layers Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.142, year: 2010

  5. Controlled growth of porous networks in phosphide semiconductors

    Czech Academy of Sciences Publication Activity Database

    Delimitis, A.; Komninou, Ph.; Kehagias, Th.; Pavlidou, E.; Karakostas, Th.; Gladkov, Petar; Nohavica, Dušan

    2008-01-01

    Roč. 15, č. 1 (2008), s. 75-81 ISSN 1380-2224 R&D Projects: GA ČR(CZ) GA202/06/1315; GA MŠk(CZ) ME 697 Institutional research plan: CEZ:AV0Z20670512 Keywords : porous semiconductors * electrochmical analysis * transmission electron microscopy * scanning electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.959, year: 2008

  6. Zinc and phosphorus co-implantation in indium phosphide

    International Nuclear Information System (INIS)

    Yu, K.M.; Ridgway, M.C.

    1998-01-01

    Electrical activation and dopant diffusion in Zn-implanted InP after rapid thermal annealing have been investigated. For an as-implanted Zn concentration of ∼4x10 19 thinspcm -3 , only ∼7% of the implanted Zn atoms formed electrically active shallow acceptors following a 950thinsp degree C/5 s annealing cycle. The low activation was the result of rapid Zn out-diffusion emdash only ∼14% of the implanted dopant was retained after annealing. A significant enhancement in electrical activation and a reduction in Zn loss were achieved in Zn+P co-implanted samples which yielded a net hole concentration of ≤6x10 18 thinspcm -3 and >50% Zn retention. The saturation of the free hole concentration in Zn+P co-implanted samples was attributed to the formation of Zn interstitial donors and Group-V-related donor-type native defects. For comparison, Zn+Al and Zn+Al+P co-implanted samples were also examined to distinguish the relative influences of implantation-induced disorder and nonstoichiometry on electrical activation and dopant diffusion. For the given implant conditions, we found that nonstoichiometry was the dominant influence. copyright 1998 American Institute of Physics

  7. Diffusion of zinc into an unpassivated surface of indium phosphide

    International Nuclear Information System (INIS)

    Budko, T.O.; Gushchinskaya, E.V.; Emelyanenko, Yu.S.; Malyshev, S.A.

    1989-01-01

    Peculiarities are studied of the diffusion of Zn into an unpassivated surface of InP in an open gasflow system. In the region where the carrier concentration profile is described by an erfc (error function compliment), the diffusion coefficient and activation energy are determined. It is shown that thermal processes cause changes in the charge state of Zn in InP which result in a variation of the carrier profile in the semiconductor. (author)

  8. Magnetic properties of Sm-based filled skutterudite phosphides

    Energy Technology Data Exchange (ETDEWEB)

    Giri, R.; Sekine, C.; Shimaya, Y.; Shirotani, I.; Matsuhira, K.; Doi, Y.; Hinatsu, Y.; Yokoyama, M.; Amitsuka, H

    2003-05-01

    Filled skutterudites SmFe{sub 4}P{sub 12} and SmOs{sub 4}P{sub 12} have been prepared at high temperature and high pressure. The temperature dependence of electrical resistivity in both compounds shows metallic behavior. The magnetic susceptibility and specific heat measurements indicate that SmFe{sub 4}P{sub 12} shows a ferromagnetic ordering at 1.5 K, whereas SmOs{sub 4}P{sub 12} is an antiferromagnet with a T{sub N} of 4.6 K.

  9. Optically detected magnetic resonance of sulfur doped gallium phosphide

    International Nuclear Information System (INIS)

    Brower, K.L.

    1990-01-01

    The authors have recently extended our magnetic resonance capabilities to include optically detected magnetic resonance (ODMR) for purposes of studying defects in III-V compound semiconductors systems. Some of the systems of particular interest with regard to defect studies are samples implanted with particular isotopes. For example, this technique may allow one to observe the hyperfine structure of impurity donors in GaP. Other interesting material systems are the strained layer superlattices and their interfaces. GaP is one of the III-V compound semiconductors of particular interest for ODMR studies. In this paper the authors report the results of preliminary ODMR observations on as-grown sulfur doped GaP

  10. Optical Properties of Strained Wurtzite Gallium Phosphide Nanowires

    KAUST Repository

    Greil, J.; Assali, S.; Isono, Y.; Belabbes, Abderrezak; Bechstedt, F.; Valega Mackenzie, F. O.; Silov, A. Yu.; Bakkers, E. P. A. M.; Haverkort, J. E. M.

    2016-01-01

    with a theoretical analysis of strain effects is employed to establish the nature and symmetry of the transitions. We identify the emission lines to be related to localized states with significant admixture of Γ7c symmetry and not exclusively related

  11. Optical properties of electron-irradiated gallium phosphide

    International Nuclear Information System (INIS)

    Brailovskii, E.Yu.; Grigoryan, N.E.; Eritsyan, G.N.

    1980-01-01

    Results of optical absorption and photoconductivity measurements in the 0.1 to 2.4 eV range of GaP crystals irradiated with 7.5 and 50 MeV electrons are presented. The absorption of irradiated crystals near the edge can be represented by two exponential regions. In the free carrier absorption region one can observe as a result of irradiation a decrease of the power index p in the dependence α proportional to lambdap. Photoconductivity with long-time relaxation takes place in the spectral interval where the additional absorption is observed. The quenching of residual conductivity can be observed at hν=1.0eV. Variations in absorption and photoconductivity are attributed to the 'tails' of density states near the zone edges arising at introduction of both point defects and disordered regions. At hν=2.1eV one can observe a resonance band which is attributed to intra-centre transitions on point defects. A recovery of the optical properties of GaP at annealing is studied. In heavily irradiated GaP crystals point defects can form gatherings which display themselves as disordered regions. (author)

  12. Germanium-doped gallium phosphide obtained by neutron irradiation

    Science.gov (United States)

    Goldys, E. M.; Barczynska, J.; Godlewski, M.; Sienkiewicz, A.; Heijmink Liesert, B. J.

    1993-08-01

    Results of electrical, optical, electron spin resonance and optically detected magnetic resonance studies of thermal neutron irradiated and annealed at 800 °C n-type GaP are presented. Evidence is found to support the view that the main dopant introduced via transmutation of GaP, germanium, occupies cation sites and forms neutral donors. This confirms the possibility of neutron transmutation doping of GaP. Simultaneously, it is shown that germanium is absent at cation sites. Presence of other forms of Ge-related defects is deduced from luminescence and absorption data. Some of them are tentatively identified as VGa-GeGa acceptors leading to the self-compensation process. This observation means that the neutron transmutation as a doping method in application to GaP is not as efficient as for Si.

  13. High-strength laser welding of aluminum-lithium scandium-doped alloys

    Science.gov (United States)

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

    2016-11-01

    The work presents the experimental investigation of laser welding of an aluminum alloy (system Al-Mg-Li) and aluminum alloy (system Al-Cu-Li) doped with Sc. The influence of nano-structuring of the surface layer welded joint by cold plastic deformation on the strength properties of the welded joint is determined. It is founded that, regarding the deformation degree over the thickness, the varying value of the welded joint strength is different for these aluminum alloys. The strength of the plastically deformed welded joint, aluminum alloys of the Al-Mg-Li and Al-Cu-Li systems reached 0.95 and 0.6 of the base alloy strength, respectively.

  14. Indium and scandium extraction by dibenzoylmethane in the presence of salting-out agents

    International Nuclear Information System (INIS)

    Ionov, V.P.; Chicherina, N.Yu.

    1985-01-01

    The dependence of In and Sc distribution coefficients (D) on molar concentration of salting-out agents (Li, Na and K nitrates) (Csub(s)) during extraction of 0.3 and 0.1 mol/l respectively by dibenzoylmethane (DBM) solutions in benzene at the constant equilibrium pH 2.0 has been studied. Applicability of previously derived equation for the distribution coefficient, taking into account the nature and concentration of salting-out agent and solution pH, is confirmed: lgD=Ksub(D)xCsub(s)+3pH- lg Dsub(A) lgB, where Ksub(D) Sechenov parameter (tangent of inclination angle of the linear part of lgD-Csub(s) dependence); 3pH-constituent, conditioned by the effect of hydrogen ions (3-tangent of inclination angle of the dependence lgD-pH for tricharged ions); lg Dsub(A) lg-nonlinear constituent o distribution coefficient-; B-constant, characterizing the nature and concentration of reagent and diluent. Analysis of the constant B of the equation is made and it is shown, that B presents a logarithm of chelate extraction constant

  15. Isolated hepatic perfusion as a treatment for uveal melanoma liver metastases (the SCANDIUM trial)

    DEFF Research Database (Denmark)

    Olofsson, Roger; Ny, Lars; Eilard, Malin Sternby

    2014-01-01

    for patients with liver metastases is between 6 and 12 months, and no treatment has in randomized trials ever been shown to prolong survival. A previous phase II trial using isolated hepatic perfusion (IHP) has suggested a 14-month increase in overall survival compared with a historic control group consisting...... of the longest surviving patients in Sweden during the same time period (26 versus 12 months). METHODS/DESIGN: This is the protocol for a multicenter phase III trial randomizing patients with isolated liver metastases of uveal melanoma to IHP or best alternative care (BAC). Inclusion criteria include liver....... The planned sample size is 78 patients throughout five years. DISCUSSION: Patients with isolated liver metastases of uveal melanoma origin have a short expected survival and no standard treatment option exists. This is the first randomized clinical trial to evaluate IHP as a treatment option with overall...

  16. Ab initio investigation of barium-scandium-oxygen coatings on tungsten for electron emitting cathodes

    Science.gov (United States)

    Vlahos, Vasilios; Booske, John H.; Morgan, Dane

    2010-02-01

    Microwave, x-ray, and radio-frequency radiation sources require a cathode emitting electrons into vacuum. Thermionic B-type dispenser cathodes consist of BaxOz coatings on tungsten (W), where the surface coatings lower the W work function and enhance electron emission. The new and promising class of scandate cathodes modifies the B-type surface through inclusion of Sc, and their superior emissive properties are also believed to stem from the formation of a low work function surface alloy. In order to better understand these cathode systems, density-functional theory (DFT)-based ab initio modeling is used to explore the stability and work function of BaxScyOz on W(001) monolayer-type surface structures. It is demonstrated how surface depolarization effects can be calculated easily using ab initio calculations and fitted to an analytic depolarization equation. This approach enables the rapid extraction of the complete depolarization curve (work function versus coverage relation) from relatively few DFT calculations, useful for understanding and characterizing the emitting properties of novel cathode materials. It is generally believed that the B-type cathode has some concentration of Ba-O dimers on the W surface, although their structure is not known. Calculations suggest that tilted Ba-O dimers are the stable dimer surface configuration and can explain the observed work function reduction corresponding to various dimer coverages. Tilted Ba-O dimers represent a new surface coating structure not previously proposed for the activated B-type cathode. The thermodynamically stable phase of Ba and O on the W surface was identified to be the Ba0.25O configuration, possessing a significantly lower Φ value than any of the Ba-O dimer configurations investigated. The identification of a more stable Ba0.25O phase implies that if Ba-O dimers cover the surface of emitting B-type cathodes, then a nonequilibrium steady state must dominate the emitting surface. The identification of a stable and low work function Ba0.25Sc0.25O structure suggests that addition of Sc to the B-type cathode surface could form this alloy structure under operating conditions, leading to improved cathode performance and stability. Detailed comparison to previous experimental results of BaxScyOz on W surface coatings are made to both validate the modeling and aid in interpretation of experimental data. The studies presented here demonstrate that ab initio methods are powerful for understanding the fundamental physics of electron emitting materials systems and can potentially aid in the development of improved cathodes.

  17. Scandium(III) catalysis of transimination reactions. Independent and constitutionally coupled reversible processes.

    Science.gov (United States)

    Giuseppone, Nicolas; Schmitt, Jean-Louis; Schwartz, Evan; Lehn, Jean-Marie

    2005-04-20

    Sc(OTf)(3) efficiently catalyzes the self-sufficient transimination reaction between various types of C=N bonds in organic solvents, with turnover frequencies up to 3600 h(-)(1) and rate accelerations up to 6 x 10(5). The mechanism of the crossover reaction in mixtures of amines and imines is studied, comparing parallel individual reactions with coupled equilibria. The intrinsic kinetic parameters for isolated reactions cannot simply be added up when several components are mixed, and the behavior of the system agrees with the presence of a unique mediator that constitutes the core of a network of competing reactions. In mixed systems, every single amine or imine competes for the same central hub, in accordance with their binding affinity for the catalyst metal ion center. More generally, the study extends the basic principles of constitutional dynamic chemistry to interconnected chemical transformations and provides a step toward dynamic systems of increasing complexity.

  18. High-field magnetization of rare-earth ions in scandium

    DEFF Research Database (Denmark)

    Roeland, L. W.; Touborg, P.

    1978-01-01

    The magnetic moments of Tb, Dy, or Er ions in dilute Sc single-crystal alloys have been measured in fields up to 280 × 105 A/m (350 kOe). The Zeeman energies in this high field are comparable to the total crystal-field splittings. This gives rise to characteristic features in the magnetization cu...... curves. The crystal-field parameters obtained previously from experiments in low fields and the Zeeman interaction give a satisfactory quantitative acount of the experimental results....

  19. Optimizing complex scandium-3,3 benzilidene BIS [4-hydroxycoumarin] with 46Sc radiotracer

    International Nuclear Information System (INIS)

    Khanza Aktari Dewi; Muhamad Basit Febrian; Duyeh Setiawan

    2015-01-01

    Coumarin, coumarin derivatives and coumarin complex compounds known to possess biological activities such as anticancer and antiviral. The reaction between the active compound coumarin derivatives with radioisotopes Sc-46 is expected to give a complex that will be marked for further investigation of its biological activity in purpose of drug development based on coumarin. This study aims to determine the optimum conditions in the synthesis of its complex compounds as well as the physico chemical characteristics including physical properties and radiochemical purity of the complex. 3.3 benzilidene bis [4-hydroxycoumarin] ligand has successfully synthesized by reacting 4-hydroxycoumarin with benzaldehyde. Complex solids formed instantly when the solution ScCl 3 labeled by Sc-46 with a pH of 5 is reacted with a ligand solution with a pH of 11 with the optimum ratio of Sc: ligand were 1:2 with optimum labeling percentage of 99,75 ± 0,02%. FTIR analysis of complex compounds and ligands show some shift in absorption due to the formation of complex. Melting point of ligand was 234°C whilst complex compound was not yet melted in maximum range of Fischer-Jons instrument at 300°C. The complex was white reddish coloured and well soluble in DMSO. Radiochemical purity of the complex Sc-(3,3 benzilidene bis [4-hydroxycoumarin]) 2 .2H 2 O was 91.22%. Complex compound of coumarin labeled by Sc-46 has been successfully synthesized and characterized with proposed molecular formula of Sc-(3,3 benzilidene bis [4-hydroxycoumarin]) 2 .2H 2 O. (author)

  20. Effect of scandium on structure and hardening of Al–Ca eutectic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Belov, N.A., E-mail: nikolay-belov@yandex.ru [National Research and Technological University “MISIS”, 4, Leninsky pr., Moscow 119049 (Russian Federation); Naumova, E.A. [Bauman Moscow State Technical University, 5, 2 ul. Baumanskaya, Moscow, 105005 (Russian Federation); Alabin, A.N. [National Research and Technological University “MISIS”, 4, Leninsky pr., Moscow 119049 (Russian Federation); UC RUSAL, 13/1, Nikoloyamskaya st., Moscow, 109240 (Russian Federation); Matveeva, I.A. [UC RUSAL, 13/1, Nikoloyamskaya st., Moscow, 109240 (Russian Federation)

    2015-10-15

    The phase composition, structure and hardening of alloys in the aluminium corner of the Al–Ca–Sc system were studied in the range up to 10% Ca and up to 1% S≿. The experimental study (optical, scanning and transmission electron microscopy with electron-microprobe analysis, differential thermal analysis and hardness measurements) was combined with Thermo-Calc software simulation for the optimization of the alloy composition. It was shown that only phases of the binary systems (Al{sub 4}Ca and Al{sub 3}Sc) might be in equilibrium with the aluminium solid solution. It was shown that the (Al) + Al{sub 4}Ca eutectic had a much finer structure as compared with the Al–Si eutectic, which suggests a possibility of reaching higher mechanical properties as compared to commercial alloys of the A356 type. The influence of the annealing temperature within the range up to 600 °C on the structure and hardness of the Al–Ca–Sc experimental alloys was studied. It was determined that the maximum hardening corresponded to the annealing at 300 °C, which was due to the precipitation of Al{sub 3}Sc nanoparticles with their further coarsening. With an example of an Al-7.6% Ca-0.3% Sc model experimental alloy, a principal possibility of manufacturing aluminium casting alloys based on the (Al) + Al{sub 4}Ca eutectic was demonstrated. Unlike commercial alloys of the A356 type, the model alloy does not require quenching, as hardening particles are formed in the course of annealing of casting. - Highlights: • Al–Ca–Sc phase diagram in aluminum corner. • Formation of Al{sub 3}Sc nanoparticles in eutectic (Al) + Al{sub 4}Ca during heating at 300–450 °C. • Hardening and thermal stability of proposed (Al–Ca–Sc) and commercial (Al–Si–Mg, 356 type) eutectic alloys.

  1. 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.

    1976-01-01

    Tritides of such metals as Sc, Ti, and Er are useful materials for determining the effects of He accumulation in metallic solids, for example, CTR first wall materials. Such effects include lattice strain and gross deformation 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, 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. Sc is unique among the early transition and rare-earth metals in that the metal exhibits a very high room temperature T solubility (T/Sc = 0.4) with no phase transformation. Indeed, even the lattice parameters of the hcp Sc lattice are only minimally changed by T solution. Single crystal ScT/sub 0.3/ samples in two crystallographic orientations were obtained. Using a very sensitive technique, 3 He emission was measured from both these samples, as well as from fine-grained thin film Sc--T solid solution samples (ScT/sub 0.3-0.4/). The fine-grained film samples release 3 He at 2-3 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

  2. 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

  3. Enhanced multiferroic properties in scandium doped Bi2Fe4O9

    International Nuclear Information System (INIS)

    Dutta, Dimple P.; Tyagi, A. K.

    2013-01-01

    Undoped and Sc 3+ doped Bi 2 Fe 4 O 9 nanoparticles have been synthesized using sonochemical method. The phase purity of the samples was checked using powder X-rau diffraction technique. EDS analysis was done to confirm the extent of Sc 3+ doping in the samples. The size and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM). The Bi 2 Fe 4 O 9 nanoparticles show a weak ferromagnetic behavior at room temperature, which is quite different from the linear M–H relationship reported for bulk Bi 2 Fe 4 O 9 . This is mainly attributed to the uncompensated moments at the disordered particle surface resulting from the reduced coordination of the surface spins, arising due to lattice strain or oxygen deficiency. Addition of Sc 3+ dopant in varying concentrations in these Bi 2 Fe 4 O 9 nanoparticles, improves their magnetic as well as ferroelectric properties. The leakage current is considerably reduced and electric polarization increases significantly in case of Bi 2 Fe 4(1-x) Sc x O 9 (x = 0.1) nanoparticles. Hence it can be inferred that Sc 3+ doped Bi 2 Fe 4 O 9 nanoparticles shows promise as good multiferroic materials.

  4. Enhanced magnetic and ferroelectric properties in scandium doped nano Bi2Fe4O9

    International Nuclear Information System (INIS)

    Dutta, Dimple P.; Sudakar, C.; Mocherla, Pavana S.V.; Mandal, Balaji P.; Jayakumar, Onnatu D.; Tyagi, Avesh K.

    2012-01-01

    In this study we report the synthesis of undoped and Sc 3+ doped Bi 2 Fe 4 O 9 nanoparticles using sonochemical technique. X-ray diffraction reveals that all samples are single phase with no impurities detected. EDS analysis was done to confirm the extent of Sc 3+ doping in the samples. The size and morphology of the nanoparticles have been analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Bi 2 Fe 4 O 9 nanoparticles show a weak ferromagnetic behavior at room temperature, which is quite different from the linear M–H relationship reported for bulk Bi 2 Fe 4 O 9 . A magnetization of 0.144 μB/f.u. is obtained at 300 K, which is mainly attributed to the uncompensated moments at the disordered particle surface resulting from the reduced coordination of the surface spins, arising due to lattice strain or oxygen deficiency. Addition of Sc 3+ dopant in varying concentrations in these Bi 2 Fe 4 O 9 nanoparticles, improves their magnetic as well as ferroelectric properties. The leakage current is considerably reduced and electric polarization increases significantly in case of Bi 2 Fe 4(1−x) Sc x O 9 (x = 0.1) nanoparticles. Thus it can be inferred that Sc 3+ doped Bi 2 Fe 4 O 9 nanoparticles shows promise as good multiferroic materials. -- Graphical abstract: Undoped and Sc 3+ doped Bi 2 Fe 4 O 9 nanoparticles have been synthesized using sonochemical technique. The bi-functionalities of Sc 3+ doped Bi 2 Fe 4 O 9 nanoparticles have been demonstrated. The Bi 2 Fe 4(1−x) Sc x O 9 (x = 0.1) nanoparticles showed enhanced magnetic and ferroelectric properties with considerably less lossy characteristics compared to the bulk Bi 2 Fe 4 O 9 . Highlights: ► Phase pure Bi 2 Fe 4 O 9 nanostructures synthesized using a facile sonochemical technique. ► Nanoparticles show a weak ferromagnetic order at room temperature. ► Sc 3+ doping in Bi 2 Fe 4 O 9 nanoparticles alters their magnetic and ferroelectric properties. ► A magnetization of 0.166 μB/f.u. was observed for Bi 2 Fe 4(1−x) Sc x O 9 (x = 0.1) nanoparticles. ► It showed enhanced ferroelectric properties with less lossy characteristics.

  5. Mathematical modeling of complexing in the scandium-salicylic acid-isoamyl alcohol system

    International Nuclear Information System (INIS)

    Evseev, A.M.; Smirnova, N.S.; Fadeeva, V.I.; Tikhomirova, T.I.; Kir'yanov, Yu.A.

    1984-01-01

    Mathematical modeling of an equilibrium multicomponent physicochemical system for extraction of Sc salicylate complexes by isoamyl alcohol was conducted. To calculate the equilibrium concentrations of Sc complexes different with respect to the content and composition, the system of nonlinear algebraic mass balance equations was solved. Experimental data on the extraction of Sc salicylates by isoamyl alcohol versus the pH of the solution at a constant Sc concentration and different concentration of salicylate-ions were used for construction of the mathematical model. The stability constants of ScHSal 2+ , Sc(HSal) 3 , ScOH(HSal) 2 , ScoH(HSal) 2 complexes were calculated

  6. Assessment of Measurement Uncertainty Values of the Scandium Determination in Marine Sediment

    International Nuclear Information System (INIS)

    Rina-Mulyaningsih, Th.

    2005-01-01

    The result value of testing is meaningless if it isn't completed with uncertainty value. So that with the analysis result Sc in the marine sediment sample. It was assessed the uncertainty measurement of Sc analysis in marine sediment. The experiment was done in AAN Serpong laboratory. The result of calculation uncertainty on Sc analysis showed that the uncertainty components come from: preparation of sample and standard/comparator, purity of standard, counting statistics (sample and standard), repeatability, nuclear data and decay correction. The assessment on uncertainty must be done for the analysis of others elements, because each elements has difference nuclear and physical properties. (author)

  7. Development of a fluorescent chelating ligand for scandium ion having a Schiff base moiety

    Science.gov (United States)

    Yamada, Hiroshi; Kojo, Masahito; Nakahara, Tomomi; Murakami, Kumi; Kakima, Takashi; Ichiba, Hideaki; Yajima, Takehiko; Fukushima, Takeshi

    2012-05-01

    A fluorescent ligand, 1-(2-hydroxy-3-methoxybenzaldehyde)-4-aminosalicylhydrazone (HMB-ASH), was newly designed and synthesized, and its fluorescence characteristics for metal ions were investigated in the pH range 3.0-10.5 (at a difference of 0.5 for each metal). After testing 31 different metal ions, it was found that HMB-ASH was able to emit fluorescence intensely at 512 nm with an excitation wavelength of 353 nm in the presence of Sc3+, one of the rare earth metals, at pH values around 3.5 and 8.0. The other metal ions hardly showed fluorescence with HMB-ASH. The fluorescence was more intense at pH 8.0, and the detection limit of Sc3+ in a buffer solution (pH 8.0) was approximately 18.8 nmol L-1 (0.85 ppb).

  8. Conditioning of red mud for subsequent titanium and scandium recovery. A conceptual design study

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, G.; Xakalashe, B.; Kaussen, F.; Friedrich, Bernd [RWTH Aachen Univ. (Germany). IME Inst. of Process Metallurgy and Metal Recycling; Yagmurlu, B. [RWTH Aachen Univ. (Germany). IME Inst. of Process Metallurgy and Metal Recycling; MEAB Chemie Technik GmbH, Aachen (Germany)

    2017-03-15

    Leaching experiments were undertaken on red mud materials (red mud and red mud slag). The red mud slag was produced via the carbothermic reduction of red mud at high temperatures (T > 1500 C) via SAF treatment. Furthermore, iron was recovered in the smelting step to the metal phase. Ti and Sc were successfully recovered from the red mud materials by hydrometallurgical treatment. For both critical metals, it was found that sulfuric acid was the best mineral acid among others. Since direct red mud leaching had some shortcomings, a route designed to overcome them is proposed. For optimal Ti and Sc recovery from red mud a promising process flowsheet combining pyrometallurgical and hydrometallurgical treatment is proposed as follows: pyrometallurgical processing (fluxed smelting to produce calcium oxide based slag phases and controlled cooling for crystalline and glassy slags), leaching for maximized Ti- and Sc extraction and followed by a multistage precipitation (for metal recovery and solution purification). Initial trial results showed that the proposed process is promising.

  9. Structural and magnetic properties of holmium-scandium alloys and superlattices

    DEFF Research Database (Denmark)

    Bryn-Jacobsen, C.; Cowley, R.A.; McMorrow, D.F.

    1997-01-01

    The properties of Ho-Sc alloys and superlattices grown by molecular-beam epitaxy have been investigated using x-ray and neutron-diffraction techniques. Structural studies reveal that the alloy samples have different a lattice parameters for the Sc-seed layer and the Ho:Sc alloy grown on top...... of the seed layer; while the superlattices have different a lattice parameters for the Sc seed, and for both the Ho and Sc in the superlattice layers. The structural characteristics are related to the large lattice mismatches (of the order 7%) between the constituent elements. The magnetic moments...

  10. Study of iron and scandium complexing with eriochrome cyanine R and diphenylguanidine

    International Nuclear Information System (INIS)

    Chermakova, L.; Styrksh, O.R.; Yanson, Eh.Yu.; Rudzit, G.P.; Saldone, Ch.V.

    1989-01-01

    Formation conditions of the ternary mixed-ligand complexes Sc 3+ eriochromcyanine R - diphenylguanidine in the urotropin buffer solutions have been studied. The pH ranges of the maximum complexing, the optimum reagent ratios have been established. The spectrophotometric method for determination of small amounts of Sc 3+ in the form of mixed-ligand complexes has been elaborated. The Lambert's-Beer's law is valid in the concentration range 0.126-0.690 μg/ml for Sc 3+

  11. Separation of thorium ions from wolframite and scandium concentrates using graphene oxide

    Czech Academy of Sciences Publication Activity Database

    Jankovský, O.; Sedmidubský, D.; Šimek, P.; Klimová, K.; Bouša, D.; Boothroyd, C.; Macková, Anna; Sofer, Z.

    2015-01-01

    Roč. 17, č. 38 (2015), s. 25272-25277 ISSN 1463-9076 R&D Projects: GA ČR(CZ) GA15-09001S; GA ČR(CZ) GBP108/12/G108; GA MŠk LM2011019 Institutional support: RVO:61389005 Keywords : graphite oxide * reduction * oxygen Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.449, year: 2015

  12. Low Temperature Mechanical Properties of Scandium-Modified Al-Zn-Mg-Cu Alloys

    National Research Council Canada - National Science Library

    Senkov, O

    2002-01-01

    Tensile properties of three wrought alloys, (1) Al-10Zn-3Mg-1.2Cu-0.15Zr, (2) Al-10Zn-3Mg-1.2Cu-0.15Zr-0.39Mn-0.49Sc, and (3) Al-12Zn-3Mg-1.2Cu-0.15Zr-0.39Mn-0.49Sc were studied in T6 and T7 conditions at 298K and 77K...

  13. Synthesis and characterization of scandium oxide microspheres for their application in radioactive particle tracking experiments

    International Nuclear Information System (INIS)

    Goswami, Sunil; Biswal, Jayashree; Pant, H.J.; Pillai, K.T.; Bamankar, Y.R.

    2012-01-01

    Radioactive particle tracking (RPT) technique, proposed by Lin et al., is a noble technique for understanding mixing mechanisms of fluids and; evaluation and improvement of design of multiphase flow systems. In RPT technique the motion of a single radioactive particle is tracked in a flow system using an array of strategically mounted NaI(Tl) scintillation detectors around the system. The gamma emitting radioactive tracer particle being tracked is designed to be hydrodynamically similar to that of the phase being traced

  14. 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.

  15. Emission channeling studies of Indium Phosphide at low temperatures at CERN-ISOLDE

    CERN Document Server

    Amorim, Lígia Marina; Wahl, Ulrich

    $^{111}$In radioactive atoms were implanted into a single crystal of InP. After annealing for lattice recovery of implantation defects, the lattice site location of $^{111}$In/$^{111}$Cd was studied with the emission channeling technique, from room temperature ( 300K) down to 50K at CERN-ISOLDE. This work aims to test a recently developed cooling station for emission channeling experiments. InP is a material with a relatively low Debye temperature, where significant changes of atomic vibrations are expected with temperature, thus providing an ideal test ground of the effects, which can be expected to influence the data, i.e., de-channeling from lattice vibration and changes of the root mean square displacement (r.m.s.) of the atomic position of the probe atom. In the future we intend to apply these studies to monitor individual impurities or lattice constituents, with temperature, upon phase transitions as well as studying lattice sites of dopants implanted at low temperature.

  16. High-performance indium gallium phosphide/gallium arsenide heterojunction bipolar transistors

    Science.gov (United States)

    Ahmari, David Abbas

    Heterojunction bipolar transistors (HBTs) have demonstrated the high-frequency characteristics as well as the high linearity, gain, and power efficiency necessary to make them attractive for a variety of applications. Specific applications for which HBTs are well suited include amplifiers, analog-to-digital converters, current sources, and optoelectronic integrated circuits. Currently, most commercially available HBT-based integrated circuits employ the AlGaAs/GaAs material system in applications such as a 4-GHz gain block used in wireless phones. As modern systems require higher-performance and lower-cost devices, HBTs utilizing the newer, InGaP/GaAs and InP/InGaAs material systems will begin to dominate the HBT market. To enable the widespread use of InGaP/GaAs HBTs, much research on the fabrication, performance, and characterization of these devices is required. This dissertation will discuss the design and implementation of high-performance InGaP/GaAs HBTs as well as study HBT device physics and characterization.

  17. Light refractive index in indium phosphide and InP-containing solid solutions

    International Nuclear Information System (INIS)

    Yas'kov, A.D.

    1983-01-01

    Spectral and temperatUre dependences of the InP and Gasub(x)Insub(1-x)P refractive indexes in the range of 0.98-1.3 μm are measured. The obtained in this case and published earlier experimental data on refractive index dispersion of the InP and solid solutions with its participation are generalized within the framework of a simple model approach based on a consecutiVe account of measured parameters of zone structure with the solid solution composition

  18. The structural evolution and diffusion during the chemical transformation from cobalt to cobalt phosphide nanoparticles

    KAUST Repository

    Ha, Don-Hyung

    2011-01-01

    We report the structural evolution and the diffusion processes which occur during the phase transformation of nanoparticles (NPs), ε-Co to Co 2P to CoP, from a reaction with tri-n-octylphosphine (TOP). Extended X-ray absorption fine structure (EXAFS) investigations were used to elucidate the changes in the local structure of cobalt atoms which occur as the chemical transformation progresses. The lack of long-range order, spread in interatomic distances, and overall increase in mean-square disorder compared with bulk structure reveal the decrease in the NP\\'s structural order compared with bulk structure, which contributes to their deviation from bulk-like behavior. Results from EXAFS show both the Co2P and CoP phases contain excess Co. Results from EXAFS, transmission electron microscopy, X-ray diffraction, and density functional theory calculations reveal that the inward diffusion of phosphorus is more favorable at the beginning of the transformation from ε-Co to Co2P by forming an amorphous Co-P shell, while retaining a crystalline cobalt core. When the major phase of the sample turns to Co 2P, the diffusion processes reverse and cobalt atom out-diffusion is favored, leaving a hollow void, characteristic of the nanoscale Kirkendall effect. For the transformation from Co2P to CoP theory predicts an outward diffusion of cobalt while the anion lattice remains intact. In real samples, however, the Co-rich nanoparticles continue Kirkendall hollowing. Knowledge about the transformation method and structural properties provides a means to tailor the synthesis and composition of the NPs to facilitate their use in applications. © 2011 The Royal Society of Chemistry.

  19. Heterodyne pump probe measurements of nonlinear dynamics in an indium phosphide photonic crystal cavity

    DEFF Research Database (Denmark)

    Heuck, Mikkel; Combrié, S.; Lehoucq, G.

    2013-01-01

    Using a sensitive two-color heterodyne pump-probe technique, we investigate the carrier dynamics of an InP photonic crystal nanocavity. The heterodyne technique provides unambiguous results for all wavelength configurations, including the degenerate case, which cannot be investigated with the wid......Using a sensitive two-color heterodyne pump-probe technique, we investigate the carrier dynamics of an InP photonic crystal nanocavity. The heterodyne technique provides unambiguous results for all wavelength configurations, including the degenerate case, which cannot be investigated...... with the widely used homodyne technique. A model based on coupled mode theory including two carrier distributions is introduced to account for the relaxation dynamics, which is assumed to be governed by both diffusion and recombination....

  20. Non-Epitaxial Thin-Film Indium Phosphide Photovoltaics: Growth, Devices, and Cost Analysis

    Science.gov (United States)

    Zheng, Maxwell S.

    In recent years, the photovoltaic market has grown significantly as module prices have continued to come down. Continued growth of the field requires higher efficiency modules at lower manufacturing costs. In particular, higher efficiencies reduce the area needed for a given power output, thus reducing the downstream balance of systems costs that scale with area such as mounting frames, installation, and soft costs. Cells and modules made from III-V materials have the highest demonstrated efficiencies to date but are not yet at the cost level of other thin film technologies, which has limited their large-scale deployment. There is a need for new materials growth, processing and fabrication techniques to address this major shortcoming of III-V semiconductors. Chapters 2 and 3 explore growth of InP on non-epitaxial Mo substrates by MOCVD and CSS, respectively. The results from these studies demonstrate that InP optoelectronic quality is maintained even by growth on non-epitaxial metal substrates. Structural characterization by SEM and XRD show stoichiometric InP can be grown in complete thin films on Mo. Photoluminescence measurements show peak energies and widths to be similar to those of reference wafers of similar doping concentrations. In chapter 4 the TF-VLS growth technique is introduced and cells fabricated from InP produced by this technique are characterized. The TF-VLS method results in lateral grain sizes of >500 mum and exhibits superior optoelectronic quality. First generation devices using a n-TiO2 window layer along with p-type TF-VLS grown InP have reached ˜12.1% power conversion efficiency under 1 sun illumination with VOC of 692 mV, JSC of 26.9 mA/cm2, and FF of 65%. The cells are fabricated using all non-epitaxial processing. Optical measurements show the InP in these cells have the potential to support a higher VOC of ˜795 mV, which can be achieved by improved device design. Chapter 5 describes a cost analysis of a manufacturing process using an InP cell as the active layer in a monolithically integrated module. Importantly, TF-VLS growth avoids the hobbles of traditional growth: the epitaxial wafer substrate, low utilization efficiency of expensive metalorganic precursors, and high capital depreciation costs due to low throughput. Production costs are projected to be 0.76/W(DC) for the benchmark case of 12% efficient modules and would decrease to 0.40/W(DC) for the long-term potential case of 24% efficient modules.

  1. Honeycomb-Like Interconnected Network of Nickel Phosphide Heteronanoparticles with Superior Electrochemical Performance for Supercapacitors.

    Science.gov (United States)

    Liu, Shude; Sankar, Kalimuthu Vijaya; Kundu, Aniruddha; Ma, Ming; Kwon, Jang-Yeon; Jun, Seong Chan

    2017-07-05

    Transition-metal-based heteronanoparticles are attracting extensive attention in electrode material design for supercapacitors owing to their large surface-to-volume ratios and inherent synergies of individual components; however, they still suffer from limited interior capacity and cycling stability due to simple geometric configurations, low electrochemical activity of the surface, and poor structural integrity. Developing an elaborate architecture that endows a larger surface area, high conductivity, and mechanically robust structure is a pressing need to tackle the existing challenges of electrode materials. This work presents a supercapacitor electrode consisting of honeycomb-like biphasic Ni 5 P 4 -Ni 2 P (Ni x P y ) nanosheets, which are interleaved by large quantities of nanoparticles. The optimized Ni x P y delivers an ultrahigh specific capacity of 1272 C g -1 at a current density of 2 A g -1 , high rate capability, and stability. An asymmetric supercapacitor employing as-synthesized Ni x P y as the positive electrode and activated carbon as the negative electrode exhibits significantly high power and energy densities (67.2 W h kg -1 at 0.75 kW kg -1 ; 20.4 W h kg -1 at 15 kW kg -1 ). These results demonstrate that the novel nanostructured Ni x P y can be potentially applied in high-performance supercapacitors.

  2. Quasi-two-dimensional metallic hydrogen inside di-phosphide at high pressure

    International Nuclear Information System (INIS)

    Degtyarenko, N N; Mazur, E A

    2016-01-01

    The method of mathematical modelling was used for the calculation of the structural, electronic, phononic, and other characteristics of various normal phases of phosphorus hydrides with stoichiometry PH k . It was shown that the di-phosphine may form 2D lattice of the metallic hydrogen in it, stabilized by phosphorus atoms under high hydrostatic pressure. The resulting structure with the elements of H-P-H has a locally stable (or metastable) phonon spectrum. The properties of di-phosphine were compared with the properties of similar structures such as the sulphur hydrides. (paper)

  3. Modifications of gallium phosphide single crystals using slow highly charged ions and swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    El-Said, A.S., E-mail: elsaid@kfupm.edu.sa [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Wilhelm, R.A.; Heller, R.; Akhmadaliev, Sh.; Schumann, E. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Sorokin, M. [National Research Centre ’Kurchatov Institute’, Kurchatov Square 1, 123182 Moscow (Russian Federation); Facsko, S. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Trautmann, C. [GSI Helmholtz Centre for Heavy Ion Research, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64289 Darmstadt (Germany)

    2016-09-01

    GaP single crystals were irradiated with slow highly charged ions (HCI) using 114 keV {sup 129}Xe{sup (33–40)+} and with various swift heavy ions (SHI) of 30 MeV I{sup 9+} and 374 MeV–2.2 GeV {sup 197}Au{sup 25+}. The irradiated surfaces were investigated by scanning force microscopy (SFM). The irradiations with SHI lead to nanohillocks protruding from the GaP surfaces, whereas no changes of the surface topography were observed after the irradiation with HCI. This result indicates that a potential energy above 38.5 keV is required for surface nanostructuring of GaP. In addition, strong coloration of the GaP crystals was observed after irradiation with SHI. The effect was stronger for higher energies. This was confirmed by measuring an increased extinction coefficient in the visible light region.

  4. Indium phosphide-based monolithically integrated PIN waveguide photodiode readout for resonant cantilever sensors

    Energy Technology Data Exchange (ETDEWEB)

    Siwak, N. P. [Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland, College Park, Maryland 20742 (United States); Laboratory for the Physical Sciences, 8050 Greenmead Drive, College Park, Maryland 20740 (United States); Fan, X. Z.; Ghodssi, R. [Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland, College Park, Maryland 20742 (United States); Kanakaraju, S.; Richardson, C. J. K. [Laboratory for the Physical Sciences, 8050 Greenmead Drive, College Park, Maryland 20740 (United States)

    2014-10-06

    An integrated photodiode displacement readout scheme for a microelectromechanical cantilever waveguide resonator sensing platform is presented. III-V semiconductors are used to enable the monolithic integration of passive waveguides with active optical components. This work builds upon previously demonstrated results by measuring the displacement of cantilever waveguide resonators with on-chip waveguide PIN photodiodes. The on-chip integration of the readout provides an additional 70% improvement in mass sensitivity compared to off-chip photodetector designs due to measurement stability and minimized coupling loss. In addition to increased measurement stability, reduced packaging complexity is achieved due to the simplicity of the readout design. We have fabricated cantilever waveguides with integrated photodetectors and experimentally characterized these cantilever sensors with monolithically integrated PIN photodiodes.

  5. Polycrystalline indium phosphide on silicon by indium assisted growth in hydride vapor phase epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Metaferia, Wondwosen; Sun, Yan-Ting, E-mail: yasun@kth.se; Lourdudoss, Sebastian [Laboratory of Semiconductor Materials, Department of Materials and Nano Physics, KTH—Royal Institute of Technology, Electrum 229, 164 40 Kista (Sweden); Pietralunga, Silvia M. [CNR-Institute for Photonics and Nanotechnologies, P. Leonardo da Vinci, 32 20133 Milano (Italy); Zani, Maurizio; Tagliaferri, Alberto [Department of Physics Politecnico di Milano, P. Leonardo da Vinci, 32 20133 Milano (Italy)

    2014-07-21

    Polycrystalline InP was grown on Si(001) and Si(111) substrates by using indium (In) metal as a starting material in hydride vapor phase epitaxy (HVPE) reactor. In metal was deposited on silicon substrates by thermal evaporation technique. The deposited In resulted in islands of different size and was found to be polycrystalline in nature. Different growth experiments of growing InP were performed, and the growth mechanism was investigated. Atomic force microscopy and scanning electron microscopy for morphological investigation, Scanning Auger microscopy for surface and compositional analyses, powder X-ray diffraction for crystallinity, and micro photoluminescence for optical quality assessment were conducted. It is shown that the growth starts first by phosphidisation of the In islands to InP followed by subsequent selective deposition of InP in HVPE regardless of the Si substrate orientation. Polycrystalline InP of large grain size is achieved and the growth rate as high as 21 μm/h is obtained on both substrates. Sulfur doping of the polycrystalline InP was investigated by growing alternating layers of sulfur doped and unintentionally doped InP for equal interval of time. These layers could be delineated by stain etching showing that enough amount of sulfur can be incorporated. Grains of large lateral dimension up to 3 μm polycrystalline InP on Si with good morphological and optical quality is obtained. The process is generic and it can also be applied for the growth of other polycrystalline III–V semiconductor layers on low cost and flexible substrates for solar cell applications.

  6. Electrical activation and local structure of Se atoms in ion-implanted indium phosphide

    International Nuclear Information System (INIS)

    Yu, K.M.; Chan, N.; Hsu, L.

    1996-01-01

    The solid phase regrowth, dopant activation, and local environments of Se-implanted InP are investigated with ion-beam techniques and extended x-ray-absorption fine structure spectroscopy. We find that the local Se endash In structure is already established in the as-implanted amorphous InP although the Se atoms have a lower average coordination number (∼3.5) and no long-range order. After high-temperature rapid thermal annealing (950 degree C, 5 s), the amorphous InP regrows, becoming a single crystal with the Se atoms bonded to four In neighbors; however, only ∼50% of the Se becomes electrically active. Part of the Se precipitates in the form of an In endash Se phase, another part is compensated by defects which are not totally removed by annealing. The Se emdash In bond distance for a Se on a P site is 4.5% longer than the matrix In emdash P bond length, introducing large strains in the crystal. The solid solubility of Se in InP is estimated from our results to be ≅8.7x10 19 /cm 3 while the electron concentration saturates at 5.4x10 19 /cm 3 . Se atoms in InP regrown at lower temperatures in a furnace are only ∼7% electrically active and are found to have different local environments (higher coordination number and shorter bond distance) than those in the InP perfectly regrown at higher temperature. copyright 1996 American Institute of Physics

  7. Zinc and group V element co-implantation in indium phosphide

    International Nuclear Information System (INIS)

    Yu, Kin Man; Ridgway, M.C.

    2000-01-01

    Group V elements with mass ranging from 35 to 122 amu have been co-implanted with Zn in InP substrates. Co-implantation with all group V elements drastically reduced Zn out-diffusion and to a certain extent also inhibited Zn in-diffusion. The reduction in out-diffusion was insensitive to the group V element mass and thus, to implantation-induced damage. We believe the group V element excess created an In-vacancy excess that enhanced Zn substitution into the In sublattice. A maximum hole concentration of 7x10 18 cm -3 was achieved with P co-implantation. Electrochemical capacitance-voltage profiling clearly showed a decrease in hole concentration as a function of increasing group V element mass. This was attributed to differences in compensating residual implantation-induced damage

  8. Interaction of point intrinsic defects in n-type indium phosphide with acceptor clusters

    International Nuclear Information System (INIS)

    Vitovskij, N.A.; Lagunova, T.S.; Rakhimov, O.

    1984-01-01

    The rates of implanting defects of donor- and acceptor type stable at room temperature in n-InP during gamma irradiation are found to vary versus the compensating impurity type. Zinc atoms interact with defects most actively. Irradiation also brings about the growth of acceptor clusters, this growth being most markedly expressed in InP . The presence of an additional mechanism of charge-carriers scattering associated with the existence of clusters of compensating centres is verified, the temperature dependence of the effectiveness of this mechanism μ approximately Tsup(-1.2) is found

  9. UV-sensitive optical sensors based on ITO-gallium phosphide heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Oleksandr; Hidalga-Wade, F. Javier de la; Zuniga-Islas, Carlos; Abundis Patino, Jesus H. [National Institute for Astrophysics, Optics, and Electronics (INAOE), Puebla (Mexico)

    2010-04-15

    Design and characteristics of wide-band UV sensors based on ITO/GaP heterostructures are discussed. Such sensors have perfect electrical parameters and high UV-visible sensitivity in comparison with surface-barrier structures using a semi-transparent thin metal film as an electrode. Many applications require UV sensors with an effective rejection of visible radiation and a wide temperature operating interval. For this aim, the theoretical modelling of extreme selective optical sensors with a double Ag/ITO thin film on the GaP surface, in which the thin silver film serves as a narrow bandpass filter at 320 nm, has been conducted. With this modelling the optimal thickness combination for the silver and ITO films was found for the maximum rejection of the sensitivity to visible radiation (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Synthesis and characterization of hollow spherical copper phosphide (Cu 3P) nanopowders

    Science.gov (United States)

    Liu, Shuling; Qian, Yitai; Xu, Liqiang

    2009-03-01

    In this paper, hollow spherical Cu 3P nanopowders were synthesized by using copper sulfate pentahydrate (CuSO 4ṡ5H 2O) and yellow phosphorus in a mixed solvent of glycol, ethanol and water at 140-180 ∘C for 12 h. X-ray powder diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), electron diffraction pattern (ED) and transmission electronic microscopy (TEM) studies show that the as-synthesized nanocrystal is pure hexagonal phase Cu 3P with a hollow spherical morphology. Based on the TEM observations, a possible aggregation growth mechanism was proposed for the formation of Cu 3P hollow structures. Meanwhile, the effects of some key factors such as solvents, reaction temperature and reaction time on the final formation of the Cu 3P hollow structure were also discussed.

  11. Emission bands of phosphorus and calculation of band structure of rare earth phosphides

    International Nuclear Information System (INIS)

    Al'perovich, G.I.; Gusatinskij, A.N.; Geguzin, I.I.; Blokhin, M.A.; Torbov, V.I.; Chukalin, V.I.; AN SSSR, Moscow. Inst. Novykh Khimicheskikh Problem)

    1977-01-01

    The method of x-ray emission spectroscopy has been used to investigate the electronic structure of monophosphides of rare-earth metals (REM). The fluorescence K bands of phosphorus have been obtained in LaP, PrP, SmP, GdP, TbP, DyP, HoP, ErP, TmP, YbP, and LuP and also the Lsub(2,3) bands of phosphorus in ErP, TmP, YbP, and LuP. Using the Green function technique involving the muffin-tin potential, the energy spectrum for ErP has been calculated in the single-electron approximation. The hystogram of electronic state distribution N(E) is compared with the experimental K and Lsub(2,3) bands of phosphorus in ErP. The agreement between the main details of N(E) and that of x-ray spectra allows to state that the model used provides a good description of the electron density distribution in crystals of REM monophosphides. In accordance with the character of the N(E) distribution the compounds under study are classified as semimetals or semiconductors with a very narrow forbidden band

  12. DWDM laser arrays fabricated using thermal nanoimprint lithography on Indium Phosphide substrates

    DEFF Research Database (Denmark)

    Smistrup, K.; Nørregaard, J.; Mironov, A.

    2013-01-01

    by including a lambda quarter shift at the center of the grating. The need for phase shifts and multiple wavelengths eliminates some lithography methods such as holography. Typically, these lasers are produced by e-beam lithography (EBL). We present a production method based on thermal nanoimprint lithography...... during the imprint process and the narrow temperature window for imprint and separation (80°C and 55°C) ensures minimal issues with thermal mismatch between the InP substrate and the Si stamp. The imprinted InP wafers were processed in NeoPhotonics standard process line to create working lasers...

  13. Radiation and temperature effects in gallium arsenide, indium phosphide, and silicon solar cells

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.; Statler, R. L.

    1987-01-01

    The effects of radiation on performance are determined for both n+p and p+n GaAs and InP cells and for silicon n+p cells. It is found that the radiation resistance of InP is greater than that of both GaAs and Si under 1-MeV electron irradiation. For silicon, the observed decreased radiation resistance with decreased resistivity is attributed to the presence of a radiation-induced boron-oxygen defect. Comparison of radiation damage in both p+n and n+p GaAs cells yields a decreased radiation resistance for the n+p cell attributable to increased series resistance, decreased shunt resistance, and relatively greater losses in the cell's p-region. For InP, the n+p configuration is found to have greater radiation resistance than the p+n cell. The increased loss in this latter cell is attributed to losses in the cell's emitter region. Temperature dependency results are interpreted using a theoretical relation for dVoc/dT, which predicts that increased Voc should result in decreased numerical values for dPm/dT. The predicted correlation is observed for GaAs but not for InP, a result which is attributed to variations in cell processing.

  14. Modelling and design of high efficiency radiation tolerant indium phosphide space solar cells

    International Nuclear Information System (INIS)

    Goradia, C.; Geier, J.V.; Weinberg, I.

    1987-01-01

    Using a fairly comprehensive model, the authors did a parametric variation study of the InP shallow homojunction solar cell with a view to determining the maximum realistically achievable efficiency and an optimum design that would yield this efficiency. Their calculations show that with good quality epitaxial material, a BOL efficiency of about 20.3% at 1AMO, 25 0 C may be possible. The design parameters of the near-optimum cell are given. Also presented are the expected radiation damage of the performance parameters by 1MeV electrons and a possible explanation of the high radiation tolerance of InP solar cells

  15. The structural evolution and diffusion during the chemical transformation from cobalt to cobalt phosphide nanoparticles

    KAUST Repository

    Ha, Don-Hyung; Moreau, Liane M.; Bealing, Clive R.; Zhang, Haitao; Hennig, Richard G.; Robinson, Richard D.

    2011-01-01

    We report the structural evolution and the diffusion processes which occur during the phase transformation of nanoparticles (NPs), ε-Co to Co 2P to CoP, from a reaction with tri-n-octylphosphine (TOP). Extended X-ray absorption fine structure (EXAFS

  16. High Sensitivity Indium Phosphide Based Avalanche Photodiode Focal Plane Arrays, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — nLight has demonstrated highly-uniform APD arrays based on the highly sensitive InGaAs/InP material system. These results provide great promise for achieving the...

  17. Towards a fully integrated indium-phosphide membrane on silicon photonics platform

    NARCIS (Netherlands)

    van Engelen, J.P.; Pogoretskiy, V.; Smit, M.K.; van der Tol, J.J.G.M.; Jiao, Y.

    2017-01-01

    Recently a uni-traveling-carrier photodetector with high speed (> 67GHz) and a high-gain optical amplifier (110/cm at 4 kA/cm2) have been demonstrated using the InP membrane-on-Silicon (IMOS) integration technology. Passives in IMOS have shown features comparable to SOI platforms due to the tight

  18. Indium phosphide solar cell research in the United States: Comparison with non-photovoltaic sources

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

    1989-01-01

    Highlights of the InP solar cell research program are presented. Homojunction cells with efficiencies approaching 19 percent are demonstrated, while 17 percent is achieved for ITO/InP cells. The superior radiation resistance of the two latter cell configurations over both Si and GaAs cells has been shown. InP cells aboard the LIPS3 satellite show no degradation after more than a year in orbit. Computed array specific powers are used to compare the performance of an InP solar cell array to solar dynamic and nuclear systems.

  19. Low-temperature annealing of radiation defects in electron-irradiated gallium phosphide

    International Nuclear Information System (INIS)

    Kolb, A.A.; Megela, I.G.; Buturlakin, A.P.; Goyer, D.B.

    1990-01-01

    The isochronal annealing of radiation defects in high-energy electron irradiated n-GaP monocrystals within the 77 to 300 K range has been investigated by optical and electrical techniques. The changes in conductance and charge carrier mobility as functions of annealing temperature as well as the variation of optical absorption spectra of GaP under irradiation and annealing provide evidence that most of radiation defects are likely secondary complexes of defects

  20. Effect of Scandium on the Interaction of Concurrent Precipitation and Recrystallization in Commercial AA3003 Aluminum Alloy

    Science.gov (United States)

    Tu, Yiyou; Qian, Huan; Zhou, Xuefeng; Jiang, Jianqing

    2014-04-01

    In the current study, the effect of Sc addition on the interaction of concurrent precipitation and recrystallization in commercial AA3003 aluminum alloy was investigated using optical microscopy, scanning electron microscopy, and transmission electron microscopy. In case of AA3003 alloy, which was cold rolled to a true strain of 2.20 and heated at a heating rate of 150 K/s, the onset of precipitation and ending of recrystallization are signified by the critical temperature, T C ~740 K (467 °C). There is a change in the shape of the recrystallized grains from pancake-like to equiaxed shape, as the annealing temperature increases greater than T C. In case of AA3003 alloy microalloyed with 0.4 wt pct of Sc, the high no. density precipitation of coherent Al3Sc precipitates always occurs before recrystallization because of the small nucleation barrier and high rate of decomposition. This leads to extremely coarse pancake-like recrystallization grains with high fraction of low-angle grain boundaries in the entire annealing temperature range, even at a high brazing temperature of 883 K (610 °C).

  1. An attempt and significance of using scandium (Sc) indication for quantitative estimation of soil ingested by pastured cattle

    International Nuclear Information System (INIS)

    Koyama, Takeo; Sudo, Madoka; Miyamoto, Susumu; Kikuchi, Takeaki; Takahashi, Masayoshi; Kuma, Tadashi.

    1985-01-01

    Pastured beef cattle constantly ingest soil together with grass. Dried grass and silage used in winter also contain some soil. Sc occurs in soil in much greater amounts than in grass and is not absorbed by digestive canals, and the Sc content can be determined accuretely by the activation analysis method. In view of this, a technique is devised which uses Sc as an indication in estimating the amount of soil ingested by cattle, and this new method is found to be better than the conventional one with Ti indication. Accordingly, dung is collected from the same cattle at the end of the pastured and housed periods. The dung samples are dried, ground, activated and analysed. On the basis of results of this analysis, the amount of soil ingested at the end of the pastured and housed periods is estimated at 106 +- 120 and 129 +- 171 g/day, respectively, which broadly agree with values previously reported. An evaluation of the amounts of Se and Zn taken by cattle from soil is also carried out. (Nogami, K.)

  2. 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.)

  3. Novel Approach for Enhanced Scandium and Titanium Leaching Efficiency from Bauxite Residue with Suppressed Silica Gel Formation.

    Science.gov (United States)

    Alkan, Gözde; Yagmurlu, Bengi; Cakmakoglu, Seckin; Hertel, Tobias; Kaya, Şerif; Gronen, Lars; Stopic, Srecko; Friedrich, Bernd

    2018-04-04

    The need of light weight alloys for future transportation industry puts Sc and Ti under a sudden demand. While these metals can bring unique and desired properties to alloys, lack of reliable sources brought forth a supply problem which can be solved by valorization of the secondary resources. Bauxite residue (red mud), with considerable Ti and Sc content, is a promising resource for secure supply of these metals. Due to drawbacks of the direct leaching route from bauxite residue, such as silica gel formation and low selectivity towards these valuable metals, a novel leaching process based on oxidative leaching conditions, aiming more efficient and selective leaching but also considering environmental aspects via lower acid consumption, was investigated in this study. Combination of hydrogen peroxide (H 2 O 2 ) and sulfuric acid (H 2 SO 4 ) was utilized as the leaching solution, where various acid concentrations, solid-to-liquid ratios, leaching temperatures and times were examined in a comparative manner. Leaching with 2.5 M H 2 O 2 : 2.5 M H 2 SO 4 mixture at 90 °C for 30 min was observed to be the best leaching conditions with suppressed silica gel formation and the highest reported leaching efficiency with high S/L ratio for Sc and Ti; 68% and 91%; respectively.

  4. 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.

  5. Effects of minor scandium on as-cast microstructure, mechanical properties and casting fluidity of ZA84 magnesium alloy

    International Nuclear Information System (INIS)

    Pan Fusheng; Yang Mingbo; Cheng Liang

    2010-01-01

    The effects of minor Sc on the as-cast microstructure, mechanical properties and casting fluidity of the ZA84 magnesium alloy were investigated. The results indicate that the Mg 32 (Al,Zn) 49 phase in the ZA84 alloy is refined with the addition of 0.12-0.35 wt.% Sc, and the formation of the Mg 32 (Al,Zn) 49 phase is suppressed. An increase in Sc amount from 0.12 wt.% to 0.35 wt.% causes the morphology of the Mg 32 (Al,Zn) 49 phase to gradually change from coarse continuous and/or quasi-continuous net to relatively fine quasi-continuous and/or disconnected shapes. In addition, it is shown that the tensile and creep properties of the ZA84 alloy are improved, but the casting fluidity of the alloy is decreased with the addition of 0.12-0.35 wt.% Sc.

  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. 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

  8. Phonon thermal conductivity of scandium nitride for thermoelectrics from first-principles calculations and thin-film growth

    DEFF Research Database (Denmark)

    Kerdsongpanya, Sit; Hellman, Olle; Sun, Bo

    2017-01-01

    The knowledge of lattice thermal conductivity of materials under realistic conditions is vitally important since many modern technologies require either high or low thermal conductivity. Here, we propose a theoretical model for determining lattice thermal conductivity, which takes into account......-domain thermoreflectance. Our experimental results show a trend of reduction in lattice thermal conductivity with decreasing domain size predicted by the theoretical model. These results suggest a possibility to control thermal conductivity by microstructural tailoring and provide a predictive tool for the effect...... of the microstructure on the lattice thermal conductivity of materials based on ab initio calculations....

  9. Influence of scandium addition on the high-temperature grain size stabilization of oxide-dispersion-strengthened (ODS) ferritic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lulu, E-mail: lli18@ncsu.edu; Xu, Weizong; Saber, Mostafa; Zhu, Yuntian; Koch, Carl C.; Scattergood, Ronald O.

    2015-06-11

    The influence of 1–4 at% Sc addition on the thermal stability of mechanically alloyed ODS ferritic alloy was studied in this work. Sc addition was found to significantly stabilize grain size and microhardness at high temperatures. Grain sizes of samples with 1 and 4 at% Sc was found maintained in the nanoscale range at temperatures up to 1000 °C with hardness maintained at 5.6 and 6.7 GPa, respectively. The detailed microstructure was also investigated from EDS elemental mapping, where nanofeatures [ScTiO] were observed, while nanosized [YTiO] particles were rarely seen. This is probably due to the concentration difference between Sc and Y, leading to the formation of [ScTiO] favoring that of [YTiO]. Precipitation was considered as the major source for the observed high temperature stabilization. In addition, 14YT–Sc alloys without large second phases such as Ti-oxide can exhibit better performance compared to conventional ODS materials.

  10. Sc2O@Cs(126339)-C92: Di-scandium oxide cluster encapsulated into a large fullerene cage

    Science.gov (United States)

    Gu, Yong-Xin; Li, Qiao-Zhi; Li, De-Huai; Zhao, Rui-Sheng; Zhao, Xiang

    2018-04-01

    The geometric, electronic structure and thermodynamic stability of Sc2O@C92 has been characterized by using hybrid density functional theory calculations combined with statistical thermodynamic analyses. Results indicate that the isolated pentagon rule (IPR) isomers Sc2O@Cs(126339)-C92, Sc2O@C1(126367)-C92 and Sc2O@C1(126390)-C92 are favorable. Noteworthy, it is the first time to declare that fullerene isomer Cs(126339)-C92 could be considered as the suitable cage to encapsulate metallic cluster. The electronic properties of these three isomers were performed with frontier molecular orbital (HOMO and LUMO) analyses and bond order calculations. Finally, 13C NMR and UV-vis-NIR spectra were simulated to provide valuable information for future experiments.

  11. Scandium doped Ge2Sb2Te5 for high-speed and low-power-consumption phase change memory

    Science.gov (United States)

    Wang, Yong; Zheng, Yonghui; Liu, Guangyu; Li, Tao; Guo, Tianqi; Cheng, Yan; Lv, Shilong; Song, Sannian; Ren, Kun; Song, Zhitang

    2018-03-01

    To bridge the gap of access time between memories and storage systems, the concept of storage class memory has been put forward based on emerging nonvolatile memory technologies. For all the nonvolatile memory candidates, the unpleasant tradeoff between operation speed and retention seems to be inevitable. To promote both the write speed and the retention of phase change memory (PCM), Sc doped Ge2Sb2Te5 (SGST) has been proposed as the storage medium. Octahedral Sc-Te motifs, acting as crystallization precursors to shorten the nucleation incubation period, are the possible reason for the high write speed of 6 ns in PCM cells, five-times faster than that of Ge2Sb2Te5 (GST) cells. Meanwhile, an enhanced 10-year data retention of 119 °C has been achieved. Benefiting from both the increased crystalline resistance and the inhibited formation of the hexagonal phase, the SGST cell has a 77% reduction in power consumption compared to the GST cell. Adhesion of the SGST/SiO2 interface has been strengthened, attributed to the reduced stress by forming smaller grains during crystallization, guaranteeing the reliability of the device. These improvements have made the SGST material a promising candidate for PCM application.

  12. 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

  13. Controlled Synthesis of Uniform Cobalt Phosphide Hyperbranched Nanocrystals Using Tri- n -octylphosphine Oxide as a Phosphorus Source

    KAUST Repository

    Zhang, Haitao; Ha, Don-Hyung; Hovden, Robert; Kourkoutis, Lena Fitting; Robinson, Richard D.

    2011-01-01

    A new method to produce hyperbranched Co 2P nanocrystals that are uniform in size, shape, and symmetry was developed. In this reaction tri-n-octylphosphine oxide (TOPO) was used as both a solvent and a phosphorus source. The reaction exhibits a novel monomer-saturation-dependent tunability between Co metal nanoparticle (NP) and Co 2P NP products. The morphology of Co 2P can be controlled from sheaflike structures to hexagonal symmetric structures by varying the concentration of the surfactant. This unique product differs significantly from other reported hyperbranched nanocrystals in that the highly anisotropic shapes can be stabilized as the majority shape (>84%). This is the first known use of TOPO as a reagent as well as a coordinating background solvent in NP synthesis. © 2011 American Chemical Society.

  14. The stannylphosphide anion reagent sodium bis(triphenylstannyl) phosphide: synthesis, structural characterization, and reactions with indium, tin, and gold electrophiles.

    Science.gov (United States)

    Cummins, Christopher C; Huang, Chao; Miller, Tabitha J; Reintinger, Markus W; Stauber, Julia M; Tannou, Isabelle; Tofan, Daniel; Toubaei, Abouzar; Velian, Alexandra; Wu, Gang

    2014-04-07

    Treatment of P4 with in situ generated [Na][SnPh3] leads to the formation of the sodium monophosphide [Na][P(SnPh3)2] and the Zintl salt [Na]3[P7]. The former was isolated in 46% yield as the crystalline salt [Na(benzo-15-crown-5)][P(SnPh3)2] and used to prepare the homoleptic phosphine P(SnPh3)3, isolated in 67% yield, as well as the indium derivative (XL)2InP(SnPh3)2 (XL = S(CH2)2NMe2), isolated in 84% yield, and the gold complex (Ph3P)AuP(SnPh3)2. The compounds [Na(benzo-15-crown-5)][P(SnPh3)2], P(SnPh3)3, (XL)2InP(SnPh3)2, and (Ph3P)AuP(SnPh3)2 were characterized using multinuclear NMR spectroscopy and X-ray crystallography. The bonding in (Ph3P)AuP(SnPh3)2 was dissected using natural bond orbital (NBO) methods, in response to the observation from the X-ray crystal structure that the dative P:→Au bond is slightly shorter than the shared electron-pair P-Au bond. The bonding in (XL)2InP(SnPh3)2 was also interrogated using (31)P and (13)C solid-state NMR and computational methods. Co-product [Na]3[P7] was isolated in 57% yield as the stannyl heptaphosphide P7(SnPh3)3, following salt metathesis with ClSnPh3. Additionally, we report that treatment of P4 with sodium naphthalenide in dimethoxyethane at 22 °C is a convenient and selective method for the independent synthesis of Zintl ion [Na]3[P7]. The latter was isolated as the silylated heptaphosphide P7(SiMe3)3, in 67% yield, or as the stannyl heptaphosphide P7(SnPh3)3 in 65% yield by salt metathesis with ClSiMe3 or ClSnPh3, respectively.

  15. Photoelectronic properties of zinc phosphide crystals, films and heterojunctions. Quarterly progress report No. 1, February 26-June 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Bube, R.H.

    1979-07-01

    A closed tube method has been developed for the synthesis of Zn/sub 3/P/sub 2/ from the elements which eliminates the potential dangers associated with high P pressures. Subsequent materials synthesis will be done routinely by this method. Initial efforts at single crystal growth of Zn/sub 3/P/sub 2/ from this material yielded polycrystalline material because of nucleation along the walls of the tube. Techniques for improving the situation are being tested. Wafers of large-grain polycrystaline Zn/sub 3/P/sub 2/ have been received from Dr. A. Catalano at Delaware and will be used for exploratory research in the quarter ahead. Progress is reported on the development of a CVD apparatus for the deposition of wide bandgap oxides and sulfides on a variety of substrates including Zn/sub 3/P/sub 2/. Layer deposition by the close spaced vapor transport method to be applied to Zn/sub 3/P/sub 2/ was successfully tested using CdTe on both quartz and CdS substrates.

  16. The combined effect of titanic carbide and aluminum phosphide on the refinement of primary silicon in Al-50Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Dai Hongshang [Key Lab. of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong Univ., Jinan (China); Liu Xiangfa [Key Lab. of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong Univ., Jinan (China); Shandong Binzhou Bohai Piston Co., Ltd., Binzhou, SD (China)

    2008-12-15

    Two refinement methods for Al-50Si alloy are presented in this article: one way is using a newly developed Si-20P alloy at 1573 K: another technique is using the Si-20P alloy in company with Al-TiO{sub 2}-C mixture powder at 1473 K. Compared to the first method, the second one not only has better refinement effect on primary Si but also lower refinement temperature. These results are due to the combined effect of TiC and AlP on the refinement process, and the duplex TiC/AlP nucleus of primary silicon has been demonstrated using electron probe micro-analysis. Moreover, the reaction of Al-TiO{sub 2}-C mixture powder with increasing temperature was investigated using differential scanning calorimetry, which shows that the TiC particles are produced at about 1473 K. AlP particles combine with the in-situ TiC particles in the melt, which is the main reason for the formation of a duplex nucleus, and the disregistry between TiC and AlP in low-index planes is also discussed. (orig.)

  17. Determination of volatile, toxic hydrogen phosphides in the sediments of the Elbe river, the Elbe estuaries and the Heligoland Bay

    International Nuclear Information System (INIS)

    Gassmann, G.

    1992-01-01

    The distribution and concentraion of phosphines in the sediments of the Elbe river were determined by selective preparation and analysis. The concentration of phosphines in one kilogram wet sediment was in the range of 0.1 to 57 n g with the bulking, anaerobic mud from harbors having the highest and the sandy, aerobic sediments having the lowest concentrations. Phosphines in fluvial sediments were detected successfully for the first time applying the method described. (orig.) [de

  18. Wavelength dependence of the single pulse femtosecond laser ablation threshold of indium phosphide in the 400-2050 nm range

    International Nuclear Information System (INIS)

    Borowiec, A.; Tiedje, H.F.; Haugen, H.K.

    2005-01-01

    We present single pulse femtosecond laser ablation threshold measurements of InP obtained by optical, scanning electron, and atomic force microscopy. The experiments were conducted with laser pulses 65-175 fs in duration, in the wavelength range from 400 to 2050 nm, covering the photon energy region above and below the bandgap of InP. The ablation thresholds determined from depth and volume measurements varied from 87 mJ/cm 2 at 400 nm to 250 mJ/cm 2 at 2050 nm. In addition, crater depths and volumes were measured over a range of laser fluences extending well above the ablation threshold

  19. Chip-scale white flip-chip light-emitting diode containing indium phosphide/zinc selenide quantum dots

    Science.gov (United States)

    Fan, Bingfeng; Yan, Linchao; Lao, Yuqin; Ma, Yanfei; Chen, Zimin; Ma, Xuejin; Zhuo, Yi; Pei, Yanli; Wang, Gang

    2017-08-01

    A method for preparing a quantum dot (QD)-white light-emitting diode (WLED) is reported. Holes were etched in the SiO2 layer deposited on the sapphire substrate of the flip-chip LED by inductively coupled plasma, and these holes were then filled with QDs. An ultraviolet-curable resin was then spin-coated on top of the QD-containing SiO2 layer, and the resin was cured to act as a protecting layer. The reflective sidewall structure minimized sidelight leakage. The fabrication of the QD-WLED is simple in preparation and compatible with traditional LED processes, which was the minimum size of the WLED chip-scale integrated package. InP/ZnS core-shell QDs were used as the converter in the WLED. A blue light-emitting diode with a flip-chip structure was used as the excitation source. The QD-WLED exhibited color temperatures from 5900 to 6400 K and Commission Internationale De L'Elcairage color coordinates from (0.315, 0.325) to (0.325, 0.317), under drive currents from 100 to 400 mA. The QD-WLED exhibited stable optoelectronic properties.

  20. Controlled Synthesis of Uniform Cobalt Phosphide Hyperbranched Nanocrystals Using Tri- n -octylphosphine Oxide as a Phosphorus Source

    KAUST Repository

    Zhang, Haitao

    2011-01-12

    A new method to produce hyperbranched Co 2P nanocrystals that are uniform in size, shape, and symmetry was developed. In this reaction tri-n-octylphosphine oxide (TOPO) was used as both a solvent and a phosphorus source. The reaction exhibits a novel monomer-saturation-dependent tunability between Co metal nanoparticle (NP) and Co 2P NP products. The morphology of Co 2P can be controlled from sheaflike structures to hexagonal symmetric structures by varying the concentration of the surfactant. This unique product differs significantly from other reported hyperbranched nanocrystals in that the highly anisotropic shapes can be stabilized as the majority shape (>84%). This is the first known use of TOPO as a reagent as well as a coordinating background solvent in NP synthesis. © 2011 American Chemical Society.

  1. Influence of 2 MeV electrons irradiation on gallium phosphide light-emitting diodes reverse currents

    Directory of Open Access Journals (Sweden)

    V. G. Vorobiov

    2015-10-01

    Full Text Available Results of reverse electrophysical characteristics study of red and green LEDs, initial and irradiated with 2 MeV electrons were given. It was found that reverse current was predominantly caused by carriers tunneling at Urev ≤ 9 V, and by the avalanche multiplication at Urev ≥ 13 V, in the range U = 9 ÷ 13 V both mechanisms are available. Current increase at high voltage areas (Urev > 19 V is limited by the base resistance of diode. In the case of significant reverse currents (I > 1 mA irradiation of diodes leads to the shift of reverse current-voltage characteristics into the high voltages direction.

  2. International Conference on Indium Phosphide and Related Materials, Held in Cape Cod, Massachusetts, on 11 - 15 May 1997.

    Science.gov (United States)

    1998-01-14

    used to induce the WSE. 8 I. Bar-Joseph, K. W. Goossen , J. M. Kuo, R. F. Kopf, D. A. B. Miller, and D. S. Chemla, IV. Summary Appl. Phys. Lett. 55, 340...epitaxy," Appl. Phys. Lett., Vol. 70, pp. 96-98, 2848, June 1992 January 1997 (2) K. W. Goossen , J. E. Cunningham, M. B. Santos, and (11) K. K Loi...References I Dallesasse J.M., Holonyack N., Sugg A.R., Richard T.A., El-Zein N., Appl. Phys. Lett. 57, (1990) 2844. 2 Huffaker D.L., Shin J., Deppe D.G

  3. Solution synthesis, structure, and CO{sub 2} reduction reactivity of a Scandium(II) complex, {Sc[N(SiMe_3)_2]_3}{sup -}

    Energy Technology Data Exchange (ETDEWEB)

    Woen, David H.; Chen, Guo P.; Ziller, Joseph W.; Furche, Filipp; Evans, William J. [Department of Chemistry, University of California, Irvine, CA (United States); Boyle, Timothy J. [Sandia National Laboratories, Advanced Materials Laboratory, Albuquerque, NM (United States)

    2017-02-13

    The first crystallographically characterizable complex of Sc{sup 2+}, [Sc(NR{sub 2}){sub 3}]{sup -} (R=SiMe{sub 3}), has been obtained by LnA{sub 3}/M reactions (Ln=rare earth metal; A=anionic ligand; M=alkali metal) involving reduction of Sc(NR{sub 2}){sub 3} with K in the presence of 2.2.2-cryptand (crypt) and 18-crown-6 (18-c-6) and with Cs in the presence of crypt. Dark maroon [K(crypt)]{sup +}, [K(18-c-6)]{sup +}, and [Cs(crypt)]{sup +} salts of the [Sc(NR{sub 2}){sub 3}]{sup -} anion are formed, respectively. The formation of this oxidation state of Sc is also indicated by the eight-line EPR spectra arising from the I=7/2 {sup 45}Sc nucleus. The Sc(NR{sub 2}){sub 3} reduction differs from Ln(NR{sub 2}){sub 3} reactions (Ln=Y and lanthanides) in that it occurs under N{sub 2} without formation of isolable reduced dinitrogen species. [K(18-c-6)][Sc(NR{sub 2}){sub 3}] reacts with CO{sub 2} to produce an oxalate complex, {K_2(18-c-6)_3}{[(R_2N)_3Sc]_2(μ-C_2O_4-κ"1O:κ"1O'')}, and a CO{sub 2}{sup -} radical anion complex, [(R{sub 2}N){sub 3}Sc(μ-OCO-κ{sup 1}O:κ{sup 1}O')K(18-c-6)]{sub n}. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Thermal effects on cavity stability of chromium- and neodymium-doped gadolinium scandium gallium garnet laser under solar-simulator pumping

    Science.gov (United States)

    Kim, Kyong H.; Venable, Demetrius D.; Brown, Lamarr A.; Lee, Ja H.

    1991-01-01

    Results are presented on testing a Cr- and Nd-codoped Gd-Sc-Ga-garnet (Cr:Nd:GSGG) crystal and a Nd:YAG crystal (both of 3.2 mm diam and 76-mm long) for pulsed and CW laser operations using a flashlamp and solar simulator as pumping sources. Results from experiments with the flashlamp show that, at pulse lengths of 0.11, 0.28, and 0.90 ms, the slope efficiency of the Cd:Nd:GSGG crystal was higher than that of the Nd:YAG crystal and increased with pulse width. With the solar simulator, however, the CW laser operation of the Cr:Nd:GSGG crystal was limited to intensities not greater than 1500 solar constants, while the Nd:YAG laser successfully performed for all pump beam intensities available. It was found that the exposure for several minutes of the Cr:Nd:GSGG crystal to pump beam intensity of 3000 solar constants led to its damage by thermal cracking, indicating that a better solar-pumped CW laser performance may be difficult to realize with rod geometry.

  5. Syntheses, characterization and nonlinear optical properties of sodium-scandium carbonate Na5Sc(CO3)4·2H2O

    Science.gov (United States)

    Chen, Jie; Luo, Min; Ye, Ning

    2014-10-01

    A novel nonlinear optical (NLO) material Na5Sc(CO3)4·2H2O has been synthesized under a subcritical hydrothermal condition. The structure is determined by single-crystal X-ray diffraction and further characterized by TG analyses and UV-vis-NIR diffuse reflectance spectrum. It crystallizes in the tetragonal space group P-421c, with a = b = 7.4622(6) Å, C = 11.5928(15) Å. The Second-harmonic generation (SHG) on polycrystalline samples was measured using the Kurtz and Perry technique, which indicated that Na5Sc(CO3)4·2H2O was a phase-matchable material, and its measured SHG coefficient was about 1.8 times as large as that of d36 (KDP). The results from the UV-vis diffuse reflectance spectroscopy study of the powder samples indicated that the short-wavelength absorption edges of Na5Sc(CO3)4·2H2O is about 220 nm, suggesting that this crystal is a promising UV nonlinear optical (NLO) materials.

  6. Structure, phonons and related properties in zinc-IV-nitride (IV = silicon, germanium, tin), scandium nitride, and rare-earth nitrides

    Science.gov (United States)

    Paudel, Tula R.

    This thesis presents a study of the phonons and related properties in two sets of nitride compounds, whose properties are until now relatively poorly known. The Zn-IV-N2 group of compounds with the group IV elements Si, Ge and Sn, form a series analogous to the well known III-N nitride series with group III element Al, Ga, In. Structurally, they can be derived by doubling the period of III-V compounds in the plane in two directions and replacing the group-III elements with Zn and a group-IV element in a particular ordered pattern. Even though they are similar to the well-known III-V nitride compounds, the study of the properties of these materials is in its early stages. The phonons in these materials and their relation to the phonons in the corresponding group-III nitrides are of fundamental interest. They are also of practical interest because the phonon related spectra such as infrared absorption and Raman spectroscopy are sensitive to the structural quality of the material and can thus be used to quantify the degree of crystalline perfection of real samples. First-principles calculations of the phonons and related ground state properties of these compounds were carried out using Density Functional Perturbation Theory (DFPT) with the Local Density Approximation (LDA) for exchange and correlation and using a pseudopotential plane wave implementation which was developed by several authors over the last decades. The main focus of our study is on the phonons at the center of the Brillouin zone because the latter are most directly related to commonly used spectroscopies to probe the vibrations in a solid: infrared reflectivity and Raman spectroscopy. For a semiconducting or insulating compound, a splitting occurs between transverse and longitudinal phonons at the Gamma-point because of the long-range nature of electrostatic forces. The concepts required to handle this problem are reviewed. Our discussion emphasizes how the various quantities required are related to various types of derivatives of the total energy versus perturbation parameters. Essentially, the long-range forces have to be treated explicitly in terms of the Born effective charge tensors which are the mixed second derivatives of the total energy of the system with respect to static electric fields and atomic displacements whereas the short-range part of the force constants is obtained from second derivatives versus atomic displacements. The second derivatives versus electrostatic field give the high-frequency dielectric function. The longitudinal and transverse response of the solid is then obtained from the calculation of the frequency dependent dielectric response function in the frequency range of the phonons. We thus present as results: first the equilibrium structure, i.e. the optimized lattice constants and internal coordinates which form the starting point for any study of the vibrational modes; second the vibrational modes at Gamma including their LO-TO splittings, third, the Born effective charges and the dielectric functions which are directly related to the experimental infrared spectra. In order to obtain the Raman intensities, one needs the derivatives of the electric susceptibility versus atomic displacements. (Abstract shortened by UMI.)

  7. The Isomers of Gadolinium Scandium Nitride Clusterfullerenes GdxSc3-xN@C80 (x=1, 2) and Their Influence on Cluster Structure

    Czech Academy of Sciences Publication Activity Database

    Yang, S.; Popov, A.; Kalbáč, Martin; Dunsch, L.

    2008-01-01

    Roč. 14, č. 7 (2008), s. 2084-2092 ISSN 0947-6539 Institutional research plan: CEZ:AV0Z40400503 Keywords : cluster compounds * fullerenes * lanthanides * structure elucidation Subject RIV: CG - Electrochemistry Impact factor: 5.454, year: 2008

  8. Enhanced magnetic and ferroelectric properties in scandium doped nano Bi{sub 2}Fe{sub 4}O{sub 9}

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Dimple P., E-mail: dimpled@barc.gov.in [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sudakar, C.; Mocherla, Pavana S.V. [Department of Physics, IIT Madras, Chennai 600 036 (India); Mandal, Balaji P.; Jayakumar, Onnatu D. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tyagi, Avesh K., E-mail: aktyagi@barc.gov.in [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2012-08-15

    In this study we report the synthesis of undoped and Sc{sup 3+} doped Bi{sub 2}Fe{sub 4}O{sub 9} nanoparticles using sonochemical technique. X-ray diffraction reveals that all samples are single phase with no impurities detected. EDS analysis was done to confirm the extent of Sc{sup 3+} doping in the samples. The size and morphology of the nanoparticles have been analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Bi{sub 2}Fe{sub 4}O{sub 9} nanoparticles show a weak ferromagnetic behavior at room temperature, which is quite different from the linear M-H relationship reported for bulk Bi{sub 2}Fe{sub 4}O{sub 9}. A magnetization of 0.144 {mu}B/f.u. is obtained at 300 K, which is mainly attributed to the uncompensated moments at the disordered particle surface resulting from the reduced coordination of the surface spins, arising due to lattice strain or oxygen deficiency. Addition of Sc{sup 3+} dopant in varying concentrations in these Bi{sub 2}Fe{sub 4}O{sub 9} nanoparticles, improves their magnetic as well as ferroelectric properties. The leakage current is considerably reduced and electric polarization increases significantly in case of Bi{sub 2}Fe{sub 4(1-x)}Sc{sub x}O{sub 9} (x = 0.1) nanoparticles. Thus it can be inferred that Sc{sup 3+} doped Bi{sub 2}Fe{sub 4}O{sub 9} nanoparticles shows promise as good multiferroic materials. -- Graphical abstract: Undoped and Sc{sup 3+} doped Bi{sub 2}Fe{sub 4}O{sub 9} nanoparticles have been synthesized using sonochemical technique. The bi-functionalities of Sc{sup 3+} doped Bi{sub 2}Fe{sub 4}O{sub 9} nanoparticles have been demonstrated. The Bi{sub 2}Fe{sub 4(1-x)}Sc{sub x}O{sub 9} (x = 0.1) nanoparticles showed enhanced magnetic and ferroelectric properties with considerably less lossy characteristics compared to the bulk Bi{sub 2}Fe{sub 4}O{sub 9}. Highlights: Black-Right-Pointing-Pointer Phase pure Bi{sub 2}Fe{sub 4}O{sub 9} nanostructures synthesized using a facile sonochemical technique. Black-Right-Pointing-Pointer Nanoparticles show a weak ferromagnetic order at room temperature. Black-Right-Pointing-Pointer Sc{sup 3+} doping in Bi{sub 2}Fe{sub 4}O{sub 9} nanoparticles alters their magnetic and ferroelectric properties. Black-Right-Pointing-Pointer A magnetization of 0.166 {mu}B/f.u. was observed for Bi{sub 2}Fe{sub 4(1-x)}Sc{sub x}O{sub 9} (x = 0.1) nanoparticles. Black-Right-Pointing-Pointer It showed enhanced ferroelectric properties with less lossy characteristics.

  9. 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.

  10. The application of spectrographic analysis to the radioisotope production control. II. Analysis of calcium-45, scandium-46, nickel-63, and copper-64 solutions

    International Nuclear Information System (INIS)

    Capdevila, C.; Roca, M.

    1972-01-01

    Semi-quantitative and quantitative determinations of both the radioactive and the target element in each radioisotope are described. The copper-spark technique was used except for Cu determinations, that need silver or.graphite electro des. Inter-element effects and their compensation through the use of Bi, 6a, In, Ho, Pd, TI and Y as reference elements was examined. For the determination of Ca in Ca-45 samples, Ba, La, Li and Sr were also tested. Good results are achieved with Li for Ca, Y for Sc,Ti and Ni, and either In or Y for Cu and Zn. (Author) 7 refs

  11. Formation of scandium nitride (ScN) layer on gallium arsenide (GaAs) substrate using a combined technique of e-beam evaporator and ammonia annealing treatment

    Energy Technology Data Exchange (ETDEWEB)

    Yong Shee Meng, Alvin [Institute of Nano Optoelectronics Research and Technology (INOR), sains@usm, Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang (Malaysia); Zainal, Norzaini, E-mail: norzaini@usm.my [Nano Optoelectronics Research and Laboratory, Universiti Sains Malaysia, sains@usm, Persiaran Bukit Jambul, 11900, Bayan Lepas, Penang (Malaysia); Hassan, Zainuriah; Ibrahim, Kamarulazizi [Institute of Nano Optoelectronics Research and Technology (INOR), sains@usm, Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang (Malaysia)

    2015-12-30

    Graphical abstract: - Highlights: • Forming ScN layer using electron e-beam evaporator with successive NH{sub 3} annealing thermal has been successfully demonstrated. • NH{sub 3} annealing played the role in changing the grain structure of the ScN layer. • The existence of Sc−N bonds was confirmed by XPS measurement. • The 900 °C annealed ScN layer showed the best structural and optical characteristics. • ScN layer annealed at 980 °C exhibited poor structural and optical characteristics. - Abstract: A demonstration on a new technique of growing ScN using electron beam (e-beam) evaporator, coupled with successive ammonia (NH{sub 3}) annealing treatment is presented in this paper. The annealing temperature was varied at 750, 800, 850, 900 and 980 °C in order to obtain the best ScN layer. It was found that as the annealing temperature increased, the surface morphology of the ScN layer changed and ScN grains formed abundantly on the surface. The best surface of ScN layer was found in the 900 °C annealed sample. However, the roughness of the ScN increased with temperature. The photoluminescence (PL) peak of the near-to-band-edge (NBE) of ScN was observable in all samples and its intensity was the highest in the 900 °C annealed sample. Note that when the annealing treatment was conducted at 980 °C, the GaN PL peak is observable. Raman peaks of TO(X) of ScN were much evident at the annealing temperature above 900 °C. The formation of Sc−N bonds was confirmed by X-ray spectroscopy (XPS) measurement. In the end of this work, we propose that the formation of ScN using the above techniques was successful, with thermal annealing at the temperature of 900 °C.

  12. Formation of scandium nitride (ScN) layer on gallium arsenide (GaAs) substrate using a combined technique of e-beam evaporator and ammonia annealing treatment

    International Nuclear Information System (INIS)

    Yong Shee Meng, Alvin; Zainal, Norzaini; Hassan, Zainuriah; Ibrahim, Kamarulazizi

    2015-01-01

    Graphical abstract: - Highlights: • Forming ScN layer using electron e-beam evaporator with successive NH_3 annealing thermal has been successfully demonstrated. • NH_3 annealing played the role in changing the grain structure of the ScN layer. • The existence of Sc−N bonds was confirmed by XPS measurement. • The 900 °C annealed ScN layer showed the best structural and optical characteristics. • ScN layer annealed at 980 °C exhibited poor structural and optical characteristics. - Abstract: A demonstration on a new technique of growing ScN using electron beam (e-beam) evaporator, coupled with successive ammonia (NH_3) annealing treatment is presented in this paper. The annealing temperature was varied at 750, 800, 850, 900 and 980 °C in order to obtain the best ScN layer. It was found that as the annealing temperature increased, the surface morphology of the ScN layer changed and ScN grains formed abundantly on the surface. The best surface of ScN layer was found in the 900 °C annealed sample. However, the roughness of the ScN increased with temperature. The photoluminescence (PL) peak of the near-to-band-edge (NBE) of ScN was observable in all samples and its intensity was the highest in the 900 °C annealed sample. Note that when the annealing treatment was conducted at 980 °C, the GaN PL peak is observable. Raman peaks of TO(X) of ScN were much evident at the annealing temperature above 900 °C. The formation of Sc−N bonds was confirmed by X-ray spectroscopy (XPS) measurement. In the end of this work, we propose that the formation of ScN using the above techniques was successful, with thermal annealing at the temperature of 900 °C.

  13. Scandium and vanadium borohydride ammoniates: Enhanced dehydrogenation behavior upon coordinative expansion and establishment of Hδ+⋯−δH interactions

    International Nuclear Information System (INIS)

    Tang, Ziwei; Yuan, Feng; Gu, Qinfen; Tan, Yingbin; Chen, Xiaowei; Jensen, Craig M.; Yu, Xuebin

    2013-01-01

    Graphical abstract: Two novel metal borohydride ammoniates—ScLi(BH 4 ) 4 ·4NH 3 and V(BH 4 ) 3 ·3NH 3 are shown to exhibit superior dehydrogenation performances established upon intensive interactions and balanced stoichiometry of dihydrogen. -- Abstract: LiSc(BH 4 ) 4 ·4NH 3 and V(BH 4 ) 3 ·3NH 3 , two novel metal borohydride ammoniates (MBAs), have been successfully synthesized via ball-milling the mixtures of MCl 3 ·xNH 3 (M = Sc, V and x = 3, 4) with LiBH 4 . Structure analysis reveals that LiSc(BH 4 ) 4 ·4NH 3 crystallizes in an orthorhombic structure with lattice parameters of a = 7.4376(3) Å, b = 11.1538(5) Å and c = 14.5132(7) Å and space group of Pc2 1 n, in which the base octahedral units are composed of central metal and an equivalent number of BH 4 and NH 3 units, distinct from other reported MBAs. Base units with the above constitution are also observed in the crystal structure of V(BH 4 ) 3 ·3NH 3 , which is identified as a cubic structure with lattice parameters of a = 10.78060(25) Å and space group of F23. These two compounds exhibit a favorable dehydrogenation capability, releasing 15.1 and 14.3 wt.% high-purity hydrogen, respectively, below 300 °C. Isothermal measurements reveal that, at a constant temperature of 110 °C, which meets the operation requirement of fuel cells, >8 and >10 wt.% pure hydrogen is released from the two compounds with favorable kinetics, respectively. Moreover, by reacting with N 2 H 4 in liquid ammonia, the decomposed LiSc(BH 4 ) 4 ·4NH 3 can be partly hydrogenated and can possibly establish a system that will undergo reversible dehydrogenation. These favorable properties point to potential on-board application. The dehydrogenation capacity, purity and temperature of the two systems can be adjusted, by tuning the ratios of the starting reagents LiBH 4 and MCl 3 ·xNH 3 , to achieve expected stoichiometric proportions of BH 4 and NH 3 units, which provides a facile and viable strategy for the synthesis of modified, mono-, di- or polymetal borohydride ammoniate systems and thus tunable hydrogen storage performances

  14. Thermodynamics of the extraction of scandium(III) by the liquid cation exchangers dinonylnaphthalenesulfonic acid and bis(2-ethylhexyl) phosphoric acid

    International Nuclear Information System (INIS)

    Raieh, M.A.; Zakareia, N.; Aly, H.F.

    1979-01-01

    The thermodynamic functions for the extraction of Sc 3+ by liquid cation exchangers HD and HDEHP are determined radiometrically by the temperature coefficient method. The role of the diluent dielectric constant on the extraction of Sc 3+ by HD is also studied. The thermodynamic parameters determined indicated that the free energy variation for the extraction of Sc 3+ by HD is mainly determined by the entropic terms arising from the hydration-dehydration process of the exchanged ions. In the case of HDEHP as extractant, the free energy variations are determined mainly by the entalpic terms of the system. (author)

  15. 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.

  16. 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.

  17. Superconductivity in Ternary Rare-Earth Transition Metal Silicides and Germanides with the SCANDIUM(5) COBALT(4) SILICON(10)-TYPE Structure.

    Science.gov (United States)

    Berg, Linda Sue

    A systematic study of the superconducting and normal state properties of some ternary rare earth transition metal silicides and germanides of the Sc(,5)Co(,4)Si(,10) -type is reported in this work. Low temperature heat capacity measurements indicate the presence of a complicated phonon density of states in these structurally complex compounds. A better description of the phonon spectrum of the high T(,c) materials, Sc(,5)Rh(,4)Si(,10), Sc(,5)Ir(,4)Si(,10), and Y(,5)Os(,4)Ge(,10), given by a model proposed by Junod et al.('1), is presented and discussed. The large values of (DELTA)C/(gamma)(,n)T(,c) and the electron-phonon coupling constant for these high T(,c) compounds indicate that they are strong-coupled superconductors. Relative to other ternary superconductors, many of these materials have large Debye temperatures. The BSC theory does not seem to afford an adequate description of the supercon- ducting state in these compounds. DC electrical resistivity measurements on these compounds show resistivity behaviors deviating from those exhibited by simple metals. The (rho)(T) data for Y(,5)Ir(,4)Si(,10), Lu(,5)Rh(,4)Si(,10), Lu(,5)Ir(,4)Si(,10), and Y(,5)Os(,4)Ge(,10), indicate the presence of anomalies. Static molar magnetic susceptibility measurements performed on these compounds indicate (1) a small effective magnetic moment of 0.26(mu)(,B) on the Co atom and (2) anomalous behaviors in the Lu(,5)Rh(,4)Si(,10), Lu(,5)Ir(,4)Si(,10), Y(,5)Ir(,4)Si(,10), Lu(,5)Ir(,4)Ge(,10), and Y(,5)Rh(,4)Ge(,10) data. It is suggested that the same mechanism, namely, the forma- tion of a charge- or spin-density wave, is causing the anomalous behaviors in both the resistivity and susceptibility data. Lastly, upper critical magnetic field measurements were performed on Sc(,5)Co(,4)Si(,10), Sc(,5)Rh(,4)Si(,10), Sc(,5)Ir(,4)Si(,10), Lu(,5)Rh(,4)Si(,10), Lu(,5)Ir(,4)Si(,10), and Y(,5)Os(,4)Ge(,10). Relative to the other five samples, Y(,5)Os(,4)Ge(,10) exhibits very high values for (-dH(,c2)/dT)(,Tc) = 10.2 kOe/ K and H(,c2)(0) = 60.4 kOe. Comparing the value of (-dH(,c2)/dT)(,Tc) gained from the fit of the data to the WHH theory to the calculated (-dH(,c2)/dT)(,Tc) yields various degrees of agreement for these com- pounds. Indications are also that (1) there seems to be little or no. Pauli limiting and (2) the spin-orbit effect appears to be negligible in these compounds. *DOE Report IS-T-1215. This work was performed under contract No. W-7405-Eng-82 with the U. S. Department of Energy. ('1)A. Junod, D. Bichsel, and J. Muller, Helv. Phys. Acta 52, 580 (1979).

  18. Solution Synthesis, Structure, and CO2 Reduction Reactivity of a Scandium(II) Complex, {Sc[N(SiMe3 )2 ]3 }.

    Science.gov (United States)

    Woen, David H; Chen, Guo P; Ziller, Joseph W; Boyle, Timothy J; Furche, Filipp; Evans, William J

    2017-02-13

    The first crystallographically characterizable complex of Sc 2+ , [Sc(NR 2 ) 3 ] - (R=SiMe 3 ), has been obtained by LnA 3 /M reactions (Ln=rare earth metal; A=anionic ligand; M=alkali metal) involving reduction of Sc(NR 2 ) 3 with K in the presence of 2.2.2-cryptand (crypt) and 18-crown-6 (18-c-6) and with Cs in the presence of crypt. Dark maroon [K(crypt)] + , [K(18-c-6)] + , and [Cs(crypt)] + salts of the [Sc(NR 2 ) 3 ] - anion are formed, respectively. The formation of this oxidation state of Sc is also indicated by the eight-line EPR spectra arising from the I=7/2 45 Sc nucleus. The Sc(NR 2 ) 3 reduction differs from Ln(NR 2 ) 3 reactions (Ln=Y and lanthanides) in that it occurs under N 2 without formation of isolable reduced dinitrogen species. [K(18-c-6)][Sc(NR 2 ) 3 ] reacts with CO 2 to produce an oxalate complex, {K 2 (18-c-6) 3 }{[(R 2 N) 3 Sc] 2 (μ-C 2 O 4 -κ 1 O:κ 1 O'')}, and a CO 2 - radical anion complex, [(R 2 N) 3 Sc(μ-OCO-κ 1 O:κ 1 O')K(18-c-6)] n . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. New neutron-rich isotopes in the scandium-to-nickel region, produced by fragmentation of a 500 MeV/u 86Kr beam

    International Nuclear Information System (INIS)

    Weber, M.; Geissel, H.; Keller, H.; Magel, A.; Muenzenberg, G.; Nickel, F.; Pfuetzner, M.; Piechaczek, A.; Roeckl, E.; Rykaczewski, K.; Schall, I.; Suemmerer, K.; Donzaud, C.; Guillemaud-Mueller, D.; Mueller, A.C.; Stephan, C.; Tassan-Got, L.; Dufour, J.P.; Pravikoff, M.; Grewe, A.; Voss, B.; Vieira, D.J.

    1991-10-01

    We have measured production cross-sections of the new neutron-rich isotopes 58 Ti, 61 V, 63 Cr, 66 Mn, 69 Fe, 71 Co and neighbouring isotopes that have been identified as projectile fragments from reactions between a 500 MeV/u 86 Kr beam and a beryllium target. The isotope identification was performed with the zero-degree magnetic spectrometer FRS at GSI, using in addition time-of-flight and energy-loss mesurements. The experimental production cross-sections for the new nuclides and neighbouring isotopes are compared with an empirical parameterization. The resulting prospects for reaching even more neutron-rich isotopes, such as the doubly-magic nuclide 78 Ni, are discussed. (orig.)

  20. Short period strain balanced gallium arsenide nitride/indium arsenide nitride superlattice lattice matched to indium phosphide for mid-infrared photovoltaics

    Science.gov (United States)

    Bhusal, Lekhnath

    Dilute nitrogen-containing III-V-N alloys have been intensively studied for their unusual electronic and optical behavior in the presence of a small amount of nitrogen. Those behaviors can further be manipulated, with a careful consideration of the strain and strain balancing, for example, in the context of a strain-balanced superlattice (SL) based on those alloys. In this work, the k.p approximation and the band anti-crossing model modified for the strain have been used to describe the electronic states of the strained bulk-like GaAs1-xNx and InAs 1-yNy ternaries in the vicinity of the center of the Brillouin zone (Gamma-point). Band-offsets between the conduction and valence bands of GaAs1-xNx and InAs1-yN y have also been evaluated, before implementing them into the SL structure. By minimizing the total mechanical energy of the stack of the alternating layers of GaAs1-xNx and InAs1-yNy in the SL, the ratio of the thicknesses of the epilayers is determined to make the structure lattice-matching on the InP(001), through the strain-balancing. Mini-band energies of the strain-balanced GaAs1-xNx/InAs 1-yNy short-period SL on InP(001) is then investigated using the transfer matrix formalism. This enabled identifying the evolution of the band edge transition energies of the superlattice structure for different nitrogen compositions. Results show the potential of the new proposed design to exceed the existing limits of bulk-like InGaAsN alloys and offer the applications for photon absorption/emission energies in the range of ~0.65-0.35eV at 300K for a typical nitrogen composition of ≤5%. The optical absorption coefficient of such a SL is then estimated under the anisotropic medium approximation, where the optical absorption of the bulk structure is modified according to the anisotropy imposed by the periodic potential in the growth direction. As an application, the developed SL structure is used to investigate the performance of double, triple and quadruple junction thermophotovoltaic devices. Integration of the SL structure, which is lattice matched to InP, in the i region of the p(InGaAs)- i(SL) n(InGaAs) diode allowed the possibility of more than two junction thermophotovoltiac device with the enhanced performance in comparison to the conventional p(InGaAs)n(InGaAs) diode.

  1. Tin phosphide-based anodes for sodium-ion batteries: synthesis via solvothermal transformation of Sn metal and phase-dependent Na storage performance

    Science.gov (United States)

    Shin, Hyun-Seop; Jung, Kyu-Nam; Jo, Yong Nam; Park, Min-Sik; Kim, Hansung; Lee, Jong-Won

    2016-01-01

    There is a great deal of current interest in the development of rechargeable sodium (Na)-ion batteries (SIBs) for low-cost, large-scale stationary energy storage systems. For the commercial success of this technology, significant progress should be made in developing robust anode (negative electrode) materials with high capacity and long cycle life. Sn-P compounds are considered promising anode materials that have considerable potential to meet the required performance of SIBs, and they have been typically prepared by high-energy mechanical milling. Here, we report Sn-P-based anodes synthesised through solvothermal transformation of Sn metal and their electrochemical Na storage properties. The temperature and time period used for solvothermal treatment play a crucial role in determining the phase, microstructure, and composition of the Sn-P compound and thus its electrochemical performance. The Sn-P compound prepared under an optimised solvothermal condition shows excellent electrochemical performance as an SIB anode, as evidenced by a high reversible capacity of ~560 mAh g−1 at a current density of 100 mA g−1 and cycling stability for 100 cycles. The solvothermal route provides an effective approach to synthesising Sn-P anodes with controlled phases and compositions, thus tailoring their Na storage behaviour. PMID:27189834

  2. Sugar Blowing-Induced Porous Cobalt Phosphide/Nitrogen-Doped Carbon Nanostructures with Enhanced Electrochemical Oxidation Performance toward Water and Other Small Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chengzhou [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Fu, Shaofang [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Xu, Bo Z. [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Song, Junhua [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Shi, Qiurong [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Engelhard, Mark H. [Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland WA 99352 USA; Li, Xiaolin [Energy and Environmental Directory, Pacific Northwest National Laboratory, Richland WA 99352 USA; Beckman, Scott P. [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Sun, Junming [The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman WA 99164 USA; Du, Dan [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Lin, Yuehe [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA

    2017-06-28

    Finely controlled synthesis of high active and robust nonprecious metal catalysts with excellent catalytic efficiency in oxygen evolution reaction (OER) is extremely vital for making the water splitting process more energy-efficient and economical. Among these noble metal-free catalysts, transition-metal-based nanomaterials are considered as one of the most promising OER catalysts due to their relatively low-cost intrinsic activities, high abundance and diversity in terms of structure and morphology. In this work, we reported a facile sugar-blowing technique and low-temperature phosphorization to generate 3D self-supported metal involved carbon nanostructures, which termed as Co2P@Co/nitrogen-doped carbon (Co2P@Co/N-C). By capitalizing on the 3D porous nanostructures with high surface area, generously dispersed active sites, the intimate interaction between active sites and 3D N-doped carbon, the resultant Co2P@Co/N-C exhibited satisfying OER performance superior to CoO@Co/N-C, delivering 10 mA cm-2 at overpotential of 0.32 V. It is noting that in contrast to the substantial current density loss of RuO2, Co2P@Co/N-C showed much enhanced catalytic activity during the stability test and the 1.8-fold increase in current density was observed after stability test. Furthermore, the obtained Co2P@Co/N-C can also be served as an excellent nonprecious metal catalyst for methanol and glucose electrooxidation in alkaline media, further extending their potential applications.

  3. Electronic Properties of III-V Semiconductors under [111] Uniaxial Strain; a Tight-Binding Approach: I. Arsenides and Gallium Phosphide

    Directory of Open Access Journals (Sweden)

    Miguel E. Mora-Ramos

    2009-01-01

    Full Text Available Empleando un esquema de cálculo tight-binding que usa una base de orbitales sp3s*d5, se estudian propiedades de la estructura electrónica de un grupo de materiales semiconductores IIIV los cuales son de notable interés para la tecnología de dispositivos electrónicos y optoelectrónicos. En específico, se analiza la influencia sobre estas propiedades de una tensión aplicada según la dirección cristalográfica [111], haciendo uso de una formulación basada en la teoría de la elasticidad para establecer las posiciones relativas de los iones vecinos más próximos. Especial atención se presta a la inclusión del efecto de deformación interna de la red cristalina. Para cada material de los estudiados presentamos las dependencias de las brechas energéticas asociadas a los puntos L, X y L de la zona de Brillouin como funciones de la tensión uniaxial en AlAs, GaAs, InAs y GaP. Asimismo, reportamos expresiones de ajuste para los valores de las masas efectivas de conducción en esos cuatro materiales. La comparación de la variación de la brecha de energía en X para el GaP, calculada con nuestro modelo, y recientes resultados experimentales para la transición indirecta entre la banda de huecos pesados y la banda X de conducción arroja una muy buena concordancia.

  4. Synergy in Lignin Upgrading by a Combination of Cu-Based Mixed Oxide and Ni-Phosphide Catalysts in Supercritical Ethanol.

    Science.gov (United States)

    Korányi, Tamás I; Huang, Xiaoming; Coumans, Alessandro E; Hensen, Emiel J M

    2017-04-03

    The depolymerization of lignin to bioaromatics usually requires a hydrodeoxygenation (HDO) step to lower the oxygen content. A mixed Cu-Mg-Al oxide (CuMgAlO x ) is an effective catalyst for the depolymerization of lignin in supercritical ethanol. We explored the use of Ni-based cocatalysts, i.e. Ni/SiO 2 , Ni 2 P/SiO 2 , and Ni/ASA (ASA = amorphous silica alumina), with the aim of combining lignin depolymerization and HDO in a single reaction step. While the silica-supported catalysts were themselves hardly active in lignin upgrading, Ni/ASA displayed comparable lignin monomer yield as CuMgAlO x . A drawback of using an acidic support is extensive dehydration of the ethanol solvent. Instead, combining CuMgAlO x with Ni/SiO 2 and especially Ni 2 P/SiO 2 proved to be effective in increasing the lignin monomer yield, while at the same time reducing the oxygen content of the products. With Ni 2 P/SiO 2 , the lignin monomer yield was 53 wt %, leading to nearly complete deoxygenation of the aromatic products.

  5. Synergy in lignin upgrading by a combination of Cu-based mixed oxide and Ni-phosphide catalysts in supercritical ethanol

    NARCIS (Netherlands)

    Koranyi, T.I.; Huang, X.; Coumans, A.E.; Hensen, E.J.M.

    2017-01-01

    The depolymerization of lignin to bioaromatics usually requires a hydrodeoxygenation (HDO) step to lower the oxygen content. A mixed Cu–Mg–Al oxide (CuMgAlOx) is an effective catalyst for the depolymerization of lignin in supercritical ethanol. We explored the use of Ni-based cocatalysts, i.e.

  6. Synthesis of optimized indium phosphide/zinc sulfide core/shell nanocrystals and titanium dioxide nanotubes for quantum dot sensitized solar cells

    Science.gov (United States)

    Lee, Seungyong

    Synthesis of InP/ZnS core/shell nanocrystals and TiO 2 nanotubes and the optimization study to couple them together were explored for quantum dot sensitized solar cells. Its intrinsic nontoxicity makes the direct band gap InP/ZnS core/shell be one of the most promising semiconductor nanocrystals for optoelectric applications, with the advantage of tuning the optical absorption range in the desired solar spectrum region. Highly luminescent and monodisperse InP/ZnS nanocrystals were synthesized in a non-coordinating solvent. By varying the synthesis scheme, different size InP/ZnS nanocrystals with emission peaks ranging from 520 nm to 620 nm were grown. For the purpose of ensuring air stability, a ZnS shell was grown. The ZnS shell improves the chemical stability in terms of oxidation prevention. Transmission electron microscopy (TEM) image shows that the nanocrystals are highly crystalline and monodisperse. Free-standing TiO2 nanotubes were produced by an anodization method using ammonium fluoride. The free-standing nanotubes were formed under the condition that the chemical dissolution speed associated with fluoride concentration was faster than the speed of Ti oxidation. Highly ordered free-standing anatase form TiO2 nanotubes, which are transformed by annealing at the optimized temperature, are expected to be ideal for coupling with the prepared InP/ZnS nanocrystals. Electrophoretic deposition was carried out to couple the InP/ZnS nanocrystals with the TiO2 nanotubes. Under the adjusted applied voltage condition, the current during the electrophoretic deposition decreased continuously with time. The amount of the deposited nanocrystals was estimated by calculation and the evenly deposited nanocrystals on the TiO2 nanotubes were observed by TEM.

  7. Toward High-Performance and Low-Cost Hydrogen Evolution Reaction Electrocatalysts: Nanostructuring Cobalt Phosphide (CoP) Particles on Carbon Fiber Paper.

    Science.gov (United States)

    Yu, Shu Hearn; Chua, Daniel H C

    2018-05-02

    In this communication, we facily fabricated nanostructured CoP particles (150 to 200 nm) on carbon fiber paper (CFP) for hydrogen evolution reaction (HER) by a simple two-step process via a green route. In the first step, crystalline Co 3 O 4 nanocubes (150-200 nm) were loaded on CFP through a hydrothermal process at low temperature (120 °C). Interestingly, crystalline Co 3 O 4 nanocubes with a size 150-200 nm exhibited different growth mechanisms in contrast to the crystalline Co 3 O 4 nanocubes with a size <100 nm reported earlier. In the second step, these crystalline Co 3 O 4 nanocubes were converted to catalytically active CoP particles through chemical vapor deposition (CVD) phosphorization (denoted as CoP/CFP-H). Remarkably, CoP/CFP-H exhibited a low Tafel slope of 49.7 mV/dec and only required overpotentials of 128.1, 144.4, and 190.8 mV to drive geometric current densities of -10, -20, and -100 mA cm -2 , respectively. Besides, the CoP/CFP-H also demonstrated an excellent durability in an acidic environment under 2000 sweeps at a high scan rate (100 mV s -1 ) and a 24 h chronopotentiometry testing. For comparison, CoP was also fabricated through the electrodeposition method, followed by CVD phosphorization (denoted as CoP/CFP-E). It was found that the latter had exhibited inferior activity compared to CoP/CFP-H. The good performances of CoP/CFP-H are essentially due to the rational designs of electrode: (i) the applications of highly HER active CoP electrocatalyst, (ii) the intimate contact of nanostructured CoP on carbon fibers, and (iii) the large electrochemical surface area at electrocatalyst/electrolyte interface due to the large retaining of particles features after phosphorization. Notably, the intermediate Co 3 O 4 /CFP can serve as a platform to develop other cobalt-based functional materials.

  8. Reaction of the (111) faces of single-crystal indium phosphide with alkylating agents: evidence for selective reaction of the p-rich face

    Energy Technology Data Exchange (ETDEWEB)

    Spool, A.M.; Daube, K.A.; Mallouk, T.E.; Belmont, J.A.; Wrighton, M.S.

    1986-05-28

    We wish to report that the P-rich, (111)B, face of single-crystal InP, but not the In-rich, (111)A, face of the same crystal, reacts with molecular reagents to yield surface-bound material derived from the apparent alkylation of a surface P atom. Exploitation of surface functional groups has been demonstrated to be very important in the attachment of molecular reagents and polymers to electrode surfaces. Electrodes derivatized with molecules have potential uses in analysis, fuel cells, electrosynthetic cells, and photoelectrochemical cells. We now wish to present evidence showing that an important photoelectrode material, InP, can be functionalized with molecules by reaction of the P-rich, (111)B, face with alkylating reagents.

  9. International Conference on Indium Phosphide and Related Materials (22nd) (IPRM) held on 31 May-4 Jun 2010, at Takamatsu Symbol Tower, Kagawa, Japan

    Science.gov (United States)

    2010-08-13

    Bergman. M. J. Choc . M. T. Bulsara, E. A. Fitzgerald. D. Smith. D. Clark. R. Thompson, C. Drazek. N. Daval. L. Benaissa, F. Augendre, "A high...architectures on a single-chip in order to optimize components with different optical properties. The execution of this integration strategy has...Chris Choc , and Charles H. Fields, "IF-sampling fourth-order bandpass AS modulator for digital receiver applications", IEEE Journal of Solid

  10. Measurement of the Two-photon Absorption Coefficient of Gallium Phosphide (GaP) Using a Dispersion-minimized Sub-10 Femtosecond Z-scan Measurement System

    Science.gov (United States)

    2012-09-01

    Mian et al. (15), if needed. Another source of error occurs when translating the sample in the z-direction that often results in the translation of...4. Li , H. P.; Kam, C. H.; Lam, Y. L.; Zhou, F.; Ji, W. Nonlinear Refraction of Undoped and Fe-doped KTiOAsO4 Crystals in the Femtosecond Regime...Semiconductors with Picosecond Laser Pulses. Phys. Rev. B 1976, 13, 3515. 15. Mian , S. M.; Taheri, B.; Wickstead, J. P. Effects of Beam Ellipticity

  11. Binding of rare earths to serum proteins and DNA

    International Nuclear Information System (INIS)

    Rosoff, B.; Spencer, H.

    1979-01-01

    In order to investigate further the physiological behavior of rare earths and rare earth chelates, studies of the binding of 46 Sc, 91 Y, and 140 La to serum proteins and to nucleic acids were performed using the methods of equilibrium dialysis and ultrafiltration. The binding of lanthanum and yttrium as the chlorides to α-globulin increased as the free rare earth concentration increased. When scandium and lanthanum were chelated in nitrilotriacetate (NTA) the binding to α-globulin was considerably less and there was no binding to albumin. The binding of 46 Sc chelated to ethylenediamine di(O-hydroxyphenylacetate) (EDDHA) was five times greater than of 46 Sc chloride. When the free scandium concentration was increased, the moles bound per mole of protein increased proportionally and the binding was reversible. Scandium was 100% filterable from a mixture of human serum and from the scandium chelates with high stability constants scandium diethylenetriaminepentaacetate (ScDTPA), scandium ethylenediaminetetraacetate (ScEDTA) and scandium cyclohexane trans-1,2-diaminetetraacetate (ScCDTA) respectively. In contrast, only 2% of the scandium was filterable when scandium nitrilotriacetate, a scandium chelate of low stability constant, was used. (Auth.)

  12. Coordination polymers of scandium sulfate. Crystal structures of (H2Bipy)[Sc(H2O)(SO4)2]2·2H2O and (H2Bipy)[HSO4]2

    International Nuclear Information System (INIS)

    Petrosyants, S.P.; Ilyukhin, A.B.

    2005-01-01

    Compounds with general formula Cat x [Sc(H 2 O) z (SO 4 ) y ]·nH 2 O (Cat=NH 4 , H 2 Bipy (Bipy - 4,4'-bipyridine), HEdp (Edp - ethylene dipyridine)) identified on element analysis data and IR spectra are synthesized. X-ray diffraction analysis of (H 2 Bipy)[Sc(H 2 O)(SO 4 ) 2 ] 2 ·2H 2 O shows that in structure of the compound chains of ScO 6 octahedron and SO 4 tetrahedrons are joined in bands by tridentate coordination of sulfate ions. Bands form skeleton in endless emptiness of which there are H 2 Bipy 2+ cations [ru

  13. 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.

  14. Kinetic phenomena in Sc films

    International Nuclear Information System (INIS)

    Stasyuk, Z.V.

    1992-01-01

    Size effects in electrical conductivity, thermoelectric power and Hall coefficient of thin scandium films have been investigated. An analysis of experimental data was made within the framework of Mayadas-Shatzkes and Tellier-Tosser-Pichard models. The transport parameters of scandium have been found. (author)

  15. Hydride vapor phase epitaxy growth of GaN, InGaN, ScN, and ScAIN

    NARCIS (Netherlands)

    Bohnen, T.

    2010-01-01

    Chemical vapor deposition (CVD); hydride vapor phase epitaxy (HVPE); gallium nitride (GaN); indium gallium nitride (InGaN); scandium nitride (ScN); scandium aluminum nitride (ScAlN); semiconductors; thin films; nanowires; III nitrides; crystal growth - We studied the HVPE growth of different III

  16. Semiconducting La2AuP3, the metallic conductor Ce2AuP3, and other rare-earth gold phosphides Ln2AuP3 with two closely related crystal structures

    International Nuclear Information System (INIS)

    Eschen, M.; Kotzyba, G.; Kuennen, B.; Jeitschko, W.

    2001-01-01

    The compounds Ln 2 AuP 3 were synthesized by reaction of the elemental components in evacuated silica tubes. Their crystal structures were determined from single-crystal diffractometer data. The compounds with Ln = La, Ce, and Pr crystallize with an orthorhombic U 2 NiC 3 type structure (Pnma, Z = 4). The structure refinement for Ce 2 AuP 3 resulted in a = 774.14(6) pm, b = 421.11(4) pm, c = 1612.3(1) pm, R = 0.019 for 1410 structure factors and 38 variable parameters. For Pr 2 AuP 3 a residual of R = 0.024 was obtained. Nd 2 AuP 3 crystallizes with a monoclinic distortion of this structure: P2 1 /c, Z = 4, a = 416.14(4) pm, b = 768.87(6) pm, c = 1647.1(2) pm, β = 104.06(1) , R = 0.022 for 1361 F values and 56 variables. The near-neighbor coordinations of the two structures are nearly the same. In both structures the gold and phosphorus atoms form two-dimensionally infinite nets, where the gold atoms are tetrahedrally coordinated by phosphorus atoms with Au-P distances varying between 245.8 and 284.2 pm. Two thirds of the phosphorus atoms form pairs with single-bond distances varying between 217.7 and 218.9 pm. Thus, using oxidation numbers the structures can be rationalized with the formulas (Ln +3 ) 2 [AuP 3 ] -6 and (Ln +3 ) 2 Au +1 (P 2 ) -4 P -3 . Accordingly, La 2 AuP 3 is a diamagnetic semiconductor. Pr 2 AuP 3 is semi-conducting with an antiferromagnetic ground state, showing metamagnetism with a critical field of B c = 0.5(±0.1) T. In contrast, the cerium compound is a metallic conductor, even though its cell volume indicates that the cerium atoms are essentially trivalent, as is also suggested by the ferro- or ferrimagnetic behavior of the compound. (orig.)

  17. The molecular beam epitaxy growth and characterization of zinc cadmium selenide/zinc cadmium magnesium selenide-indium phosphide quantum cascade structures for operation in the 3 - 5 um range

    Science.gov (United States)

    Charles, William O.

    The quantum cascade (QC) laser has captured the interest of researchers for almost three decades. In the early stages, researchers were very interested in proving the QC concept1 proposed by Kazarinov and Suris in 1971. This new concept gave researchers hope that very bulky energy inefficient infra-red (IR) lasers would be replaced with ones that are very compact, tunable and portable. Since the proposal of the QC laser concept and its first demonstration by researchers at Bell Laboratories2 in 1994, this technology has progressed to the point where it is now finding commercial applications in a variety of areas such as military counter measures, free space telecommunications, infra-red imaging and chemical spectroscopy.3-5 The success of this technology can be attributed to the coming of age of the techniques of molecular beam epitaxy (MBE) semiconductor growth and bandgap engineering. 6,7 Using MBE technology, the temperature of the source material can be stabilized by making use of a combination of proportional integral derivative (PID) controllers and thermocouple feedbacks. As a result, the material flux from the effusion cells can achieve stability better than (+/-) 1%. This flux stability together with a well-developed computer controlled shuttering mechanism make it possible to grow multi-quantum well (MQW) structures with excellent layer thickness precision (mono-layer scale) and interface quality. This stringent control of material flux is also a tool that is used by MBE growers to vary the material compositions for the growth of lattice matched and strain compensated QC structures. Today, MBE stands out as one of the premier methods for growing high performing QC lasers. The first successful demonstration of a QC laser2 was done using the InGaAs/InAlAs-InP material system. This demonstration was then repeated a few years later using GaAs/AlGaAs-InP.8 These III-V material systems were extensively studied to establish their material parameters. Given that material parameters are critically important in the process of modeling QC structures, it is not surprising that early success was achieved using these systems. Today, the best performing QC lasers operate in the 4--13 mum range and are produced using lattice matched InGaAs/InAlAs-InP. In order to produce short wavelength QC lasers, the well layer thicknesses in the active region of the device must be reduced in an effort to push the lasing energy states further apart. This reduction in well thicknesses results in the movement of the upper lasing state closer to the bandedge. This action increases the probability of the lost of lasing state electrons to the continuum. Therefore, in order to produce high performing short wavelength QC lasers, a large conduction band offset (CBO) is required. The CBO of lattice matched InGaAs/InAlAs-InP is 0.52 eV. In an attempt to produce high performing devices below 4 mum many researchers have resorted to the use of strain compensation9-11 . This approach has yielded very little improvement in performance due to electron scattering to the X and L intervalleys. This has lead to the exploration of wide bandgap material systems such as the antominides and nitrides. In this work the wide bandgap II-V Znx'Cd(1-x')Se/Zn xCdyMg(1-x-y)Se-InP will be explored for QC laser fabrication. To this end, QC lasers were designed for operation at 3--5 mum range. A Matlab-based program was written to calculate the energy level spacing within the active region of these devices. This simulation program was based on Schroindger's equation and the transfer matrix technique. Several calibration samples were grown to establish the doping levels and growth rate of the well and barrier materials. The growth rate was measured using scanning electron microscopy (SEM) and reflection high energy electron diffraction (RHEED) oscillations during MBE growth. X-ray diffraction measurements were performed to determine the lattice mismatch of the II-VI bulk layers, and therefore predict whether material composition adjustments were required to attain the lattice match condition. The samples that were grown were studied using photoluminescence (PL) to determine the bandgap of the well and barrier material. This information was then used to calculate the CBO of the II-VI MQW structure. In addition, PL studies were also carried out to look for material defects and assess the quality of the well/barrier interface. These II-VI QC samples were also subjected to Fourier transform infra-red (FTIR) absorption spectroscopy to determine the energy levels in the grown structures. After optimizing the active regions using simulation data and FTIR results, electroluminescence (EL) structures were grown and processed into QC emitters using a combination photolithography and electron beam contact deposition. The processed structures were then biased and investigated for IR emission at temperatures ranging from 80 K to room temperature.

  18. Low Temperature Reactions for the Preparation of Group 13-15 Materials from Organo-gallium(I) and -indium(I) Compounds

    National Research Council Canada - National Science Library

    Beachley, O

    1997-01-01

    ...) at 175 deg C and of neopentylgallium(I) Ga(CH2CMe3)n with P4 at 350- 400 deg C and with NH3 at 460-480 deg C in sealed tubes provide routes to indium phosphide, gallium phosphide and hexagonal gallium nitride, respectively...

  19. 77 FR 43595 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2012-07-25

    ...- dimethylphenyl)-N- (methoxyacetyl)-, methyl ester. GA080011 Safari 20 SG Dinotefuran. Insecticide. ID060014 Prozap Zinc Zinc phosphide Phosphide Pellets. (Zn3P2). KY080024 Safari 20 SG Dinotefuran. Herbicide.... Copper hydroxide D- Alanine, N-(2,6- dimethylphenyl)-N- (methoxyacetyl)-, methyl ester. VA080009 Safari...

  20. The LiHCOO-Sc(HCOO)3-H2O system at 25 and 50 deg C

    International Nuclear Information System (INIS)

    Petrova, E.V.; Itkina, L.S.

    1980-01-01

    Solubility in the LiHCOO-Sc(HCOO) 3 -H 2 O system at 25 and 50 deg C has been investigated using the isothermal method It has been ascertainedy s stem is a simple eutonic one. Solubility isotherms consist of two crystallization branches: lithium formate monohydrate and scandium formate. Scandium formate salts-out lithium formate from the solution. Lithium formate increases the solubility of scandium formate (in the eutonic solution more than 2 times as compared to its solubility in the pure water)

  1. Nano-Particle Scandate Cathode for Space Communications Phase 2, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose an improved cathode based on our novel theory of the role of scandium oxide in enhancing emission in tungsten-impregnated cathodes. Recent results have...

  2. Determination of some main elements and traces by x-ray fluorescence analysis in silicate rocks: a comparative study of two analytical techniques

    International Nuclear Information System (INIS)

    Andrade, M.D. de.

    1977-01-01

    The determinations of silicon, magnesium, iron, potassium, calcium, titanium, manganese, barium, strontium, rubidium, zirconium and scandium in felsic and mafic rocks, by X ray fluorescence analysis are presented. (author)

  3. Static dipole polarizabilities of Scn (n ≤ 15) clusters

    International Nuclear Information System (INIS)

    Xi-Bo, Li; Jiang-Shan, Luo; Wei-Dong, Wu; Yong-Jian, Tang; Hong-Yan, Wang; Yun-Dong, Guo

    2009-01-01

    The static dipole polarizabilities of scandium clusters with up to 15 atoms are determined by using the numerically finite field method in the framework of density functional theory. The electronic effects on the polarizabilities are investigated for the scandium clusters. We examine a large highest occupied molecular orbital — the lowest occupied molecular orbital (HOMO–LUMO) gap of a scandium cluster usually corresponds to a large dipole moment. The static polarizability per atom decreases slowly and exhibits local minimum with increasing cluster size. The polarizability anisotropy and the ratio of mean static polarizability to the HOMO–LUMO gap can also reflect the cluster stability. The polarizability of the scandium cluster is partially related to the HOMO–LUMO gap and is also dependent on geometrical characteristics. A strong correlation between the polarizability and ionization energy is observed. (atomic and molecular physics)

  4. Density functional study of : Electronic and optical properties

    Indian Academy of Sciences (India)

    K C Bhamu

    3Department of Physics, Swami Keshvanand Insitute of Technology, Management and Gramothan, ... Published online 20 June 2017. Abstract. This paper focusses on the electronic and optical properties of scandium-based silver delafossite.

  5. Download this PDF file

    African Journals Online (AJOL)

    big timmy

    The effects of the substitution of aluminum or scandium on the density, toughness ... density functional quantum mechanical calculation methods. ... are used in the form of an intermetallic (alloy) according to their required physical properties.

  6. Sc, Y, the lanthanoids and the actinoids

    International Nuclear Information System (INIS)

    Miller, J.D.

    1985-01-01

    Highlights of work published in 1984 are given. Solid state, studies in solution, coordination chemistry and organometallic chemistry aspects of scandium, yttrium, the rare earths and actinide compounds are covered. (U.K.)

  7. In the presence of fluoride, free Sc³⁺ is not a good predictor of Sc bioaccumulation by two unicellular algae: possible role of fluoro-complexes.

    Science.gov (United States)

    Crémazy, Anne; Campbell, Peter G C; Fortin, Claude

    2014-08-19

    We investigated the effect of fluoride complexation on scandium accumulation by two unicellular algae, Chlamydomonas reinhardtii and Pseudokirchneriella subcapitata. This trivalent metal was selected for its chemical similarities with aluminum and for its convenient radioisotope (Sc-46), which can be used as a tracer in short-term bioaccumulation studies. Scandium surface-bound concentrations (Sc(ads)) and uptake fluxes (J(int)) were estimated in the two algae over short-term (organisms.

  8. Synthesis and Isolation of the Titanium-Scandium Endohedral Fullerenes-Sc2 TiC@Ih -C80 , Sc2 TiC@D5h -C80 and Sc2 TiC2 @Ih -C80 : Metal Size Tuning of the Ti(IV) /Ti(III) Redox Potentials.

    Science.gov (United States)

    Junghans, Katrin; Ghiassi, Kamran B; Samoylova, Nataliya A; Deng, Qingming; Rosenkranz, Marco; Olmstead, Marilyn M; Balch, Alan L; Popov, Alexey A

    2016-09-05

    The formation of endohedral metallofullerenes (EMFs) in an electric arc is reported for the mixed-metal Sc-Ti system utilizing methane as a reactive gas. Comparison of these results with those from the Sc/CH4 and Ti/CH4 systems as well as syntheses without methane revealed a strong mutual influence of all key components on the product distribution. Whereas a methane atmosphere alone suppresses the formation of empty cage fullerenes, the Ti/CH4 system forms mainly empty cage fullerenes. In contrast, the main fullerene products in the Sc/CH4 system are Sc4 C2 @C80 (the most abundant EMF from this synthesis), Sc3 C2 @C80 , isomers of Sc2 C2 @C82 , and the family Sc2 C2 n (2 n=74, 76, 82, 86, 90, etc.), as well as Sc3 CH@C80 . The Sc-Ti/CH4 system produces the mixed-metal Sc2 TiC@C2 n (2 n=68, 78, 80) and Sc2 TiC2 @C2 n (2 n=80) clusterfullerene families. The molecular structures of the new, transition-metal-containing endohedral fullerenes, Sc2 TiC@Ih -C80 , Sc2 TiC@D5h -C80 , and Sc2 TiC2 @Ih -C80 , were characterized by NMR spectroscopy. The structure of Sc2 TiC@Ih -C80 was also determined by single-crystal X-ray diffraction, which demonstrated the presence of a short Ti=C double bond. Both Sc2 TiC- and Sc2 TiC2 -containing clusterfullerenes have Ti-localized LUMOs. Encapsulation of the redox-active Ti ion inside the fullerene cage enables analysis of the cluster-cage strain in the endohedral fullerenes through electrochemical measurements. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  9. The application of spectrographic analysis to the radioisotope production control. II. Analysis of calcium-45, scandium-46, nickel-63, and copper-64 solutions; Aplicacion del analisis espectrografico al control de produccion de radioisotopos. II. Analisis de soluciones de calcio-45, escandio-46, niquel-63 y cobre-64

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila, C.; Roca, M.

    1972-07-01

    Semi-quantitative and quantitative determinations of both the radioactive and the target element in each radioisotope are described. The copper-spark technique was used except for Cu determinations, that need silver or.graphite electro des. Inter-element effects and their compensation through the use of Bi, 6a, In, Ho, Pd, TI and Y as reference elements was examined. For the determination of Ca in Ca-45 samples, Ba, La, Li and Sr were also tested. Good results are achieved with Li for Ca, Y for Sc,Ti and Ni, and either In or Y for Cu and Zn. (Author) 7 refs.

  10. Saturable Absorbing Quantum Wells at 1.08 and 1.55 Micron Wavelengths for Mode Locking of Solid State Lasers

    National Research Council Canada - National Science Library

    Wicks, Gary

    1998-01-01

    Multiple quantum well designs were fabricated and tested at 1.55 microns. A series of 17 MBE fabrications were completed with deposits of various AlInAs/GaInAs alloys deposited on Indium Phosphide substrates...

  11. Yellow phosphorus-induced Brugada phenocopy.

    Science.gov (United States)

    Dharanipradab, Mayakrishnan; Viswanathan, Stalin; Kumar, Gokula Raman; Krishnamurthy, Vijayalatchumy; Stanley, Daphene Divya

    Metallic phosphides (of aluminum and phosphide) and yellow phosphorus are commonly used rodenticide compounds in developing countries. Toxicity of yellow phosphorus mostly pertains to the liver, kidney, heart, pancreas and the brain. Cardiotoxicity with associated Brugada ECG pattern has been reported only in poisoning with metallic phosphides. Brugada phenocopy and hepatic dysfunction were observed in a 29-year-old male following yellow phosphorus consumption. He had both type 1 (day1) and type 2 (day2) Brugada patterns in the electrocardiogram, which resolved spontaneously by the third day without hemodynamic compromise. Toxins such as aluminum and zinc phosphide have been reported to induce Brugada ECG patterns due to the generation of phosphine. We report the first case of yellow phosphorus-related Brugada phenocopy, without hemodynamic compromise or malignant arrhythmia. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Window structure for passivating solar cells based on gallium arsenide

    Science.gov (United States)

    Barnett, Allen M. (Inventor)

    1985-01-01

    Passivated gallium arsenide solar photovoltaic cells with high resistance to moisture and oxygen are provided by means of a gallium arsenide phosphide window graded through its thickness from arsenic rich to phosphorus rich.

  13. Monolithic Chip-Integrated Absorption Spectrometer from 3-5 microns, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A monolithically integrated indium phosphide (InP) to silicon-on-sapphire (SoS) platform is being proposed for a monolithic portable or handheld spectrometer between...

  14. Time-resolved pulse propagation in a strongly scattering material

    NARCIS (Netherlands)

    Johnson, Patrick M.; Imhof, Arnout; Bret, B.P.J.; Gomez Rivas, J.; Gomez Rivas, Jaime; Lagendijk, Aart

    2003-01-01

    Light transport in macroporous gallium phosphide, perhaps the strongest nonabsorbing scatterer of visible light, is studied using phase-sensitive femtosecond pulse interferometry. Phase statistics are measured at optical wavelengths in both reflection and transmission and compared with theory. The

  15. On-chip multi-wavelength laser sources fabricated using generic photonic integration technology

    NARCIS (Netherlands)

    Latkowski, S.; Williams, K.A.; Bente, E.A.J.M.

    Generic photonic integration technology platforms allow for design and fabrication of large complexity application specific photonic integrated circuits. Monolithic active-passive integration on indium phosphide substrate naturally enables a reliable co-integration of optical gain elements and

  16. Phosphine Toxicity: A Story of Disrupted Mitochondrial Metabolism

    Science.gov (United States)

    2016-05-24

    Phosphine and selected metal phosphides. Environ. Health Criteria 73. 5. Reeve, I. 2014. Estimation of exposure to persons in Califor- nia ...Gill. 2011. Aluminum phosphide poisoning: an unsolved riddle. J. Appl. Toxicol. 31: 499– 505 . 9. Lam, W.W., R.F. Toia & J. Casida. 1991. Oxidatively...Trends Biochem. Sci. 35: 505 –513. 43. Turrens, J.F. 2003. Mitochondrial formation of reactive oxy- gen species. J. Physiol. 552: 335–344. 44. Fridovich

  17. Immobilisation of manganese, cobalt and nickel by deep-sea-sediment microbial communities

    Digital Repository Service at National Institute of Oceanography (India)

    Sujith, P.P.; Das, A.; Mourya, B.S.; LokaBharathi, P.A.

    and their various organic derivatives in nature are contained in the living biomass. For example, Razzell and Trussell (1963) [9] addressed the interaction of Thiobacillus spp with sulfide baring ores and their role in dissolution of oxides and release... of valuable metals. Likewise, Fortin et al (1994), Basnakova and Macaskie (1996) [10-11] presented the contribution of bacteria in the formation of sulfide and phosphide minerals by chemical complexing with available constituent sulfide and phosphide groups...

  18. Semiconducting La{sub 2}AuP{sub 3}, the metallic conductor Ce{sub 2}AuP{sub 3}, and other rare-earth gold phosphides Ln{sub 2}AuP{sub 3} with two closely related crystal structures

    Energy Technology Data Exchange (ETDEWEB)

    Eschen, M.; Kotzyba, G.; Kuennen, B.; Jeitschko, W. [Anorganisch-Chemisches Inst. der Westfaelischen Wilhelms-Univ., Muenster (Germany)

    2001-07-01

    The compounds Ln{sub 2}AuP{sub 3} were synthesized by reaction of the elemental components in evacuated silica tubes. Their crystal structures were determined from single-crystal diffractometer data. The compounds with Ln = La, Ce, and Pr crystallize with an orthorhombic U{sub 2}NiC{sub 3} type structure (Pnma, Z = 4). The structure refinement for Ce{sub 2}AuP{sub 3} resulted in a = 774.14(6) pm, b = 421.11(4) pm, c = 1612.3(1) pm, R = 0.019 for 1410 structure factors and 38 variable parameters. For Pr{sub 2}AuP{sub 3} a residual of R = 0.024 was obtained. Nd{sub 2}AuP{sub 3} crystallizes with a monoclinic distortion of this structure: P2{sub 1}/c, Z = 4, a = 416.14(4) pm, b = 768.87(6) pm, c = 1647.1(2) pm, {beta} = 104.06(1) , R = 0.022 for 1361 F values and 56 variables. The near-neighbor coordinations of the two structures are nearly the same. In both structures the gold and phosphorus atoms form two-dimensionally infinite nets, where the gold atoms are tetrahedrally coordinated by phosphorus atoms with Au-P distances varying between 245.8 and 284.2 pm. Two thirds of the phosphorus atoms form pairs with single-bond distances varying between 217.7 and 218.9 pm. Thus, using oxidation numbers the structures can be rationalized with the formulas (Ln{sup +3}){sub 2}[AuP{sub 3}]{sup -6} and (Ln{sup +3}){sub 2}Au{sup +1}(P{sub 2}){sup -4}P{sup -3}. Accordingly, La{sub 2}AuP{sub 3} is a diamagnetic semiconductor. Pr{sub 2}AuP{sub 3} is semi-conducting with an antiferromagnetic ground state, showing metamagnetism with a critical field of B{sub c} = 0.5({+-}0.1) T. In contrast, the cerium compound is a metallic conductor, even though its cell volume indicates that the cerium atoms are essentially trivalent, as is also suggested by the ferro- or ferrimagnetic behavior of the compound. (orig.)

  19. 1013/second 14 MeV neutron generator for cancer therapy

    International Nuclear Information System (INIS)

    Walko, R.J.; Bacon, F.M.; Bickes, R.W. Jr.; Cowgill, D.F.; Boers, J.E.; Riedel, A.A.; O'Hagan, J.B.

    1980-01-01

    A high output D-T neutron generator is being developed at Sandia National Laboratories as a cancer therapy tool. Preliminary results have been obtained with a high vacuum deuterium accelerator consisting of a duopigatron ion source, single stage accelerator and a scandium occluder target. The ion source and accelerating system have been optimized to reliably focus a 200 mA, 200 kV deuterium ion beam onto the scandium target 1.5 m away with a beam spot size of 10 -3 m 2 . The scandium target degrades due to implantation of impurities from the unbaked vacuum system. A UHV accelerator is being fabricated which will permit a 450 0 C bakeout to alleviate the impurity problem. This system will also be compatible with the use of tritium, a necessary component of the therapy machine

  20. Rare earth sulfates

    International Nuclear Information System (INIS)

    Komissarova, L.N.; Shatskij, V.M.; Pokrovskij, A.N.; Chizhov, S.M.; Bal'kina, T.I.; Suponitskij, Yu.L.

    1986-01-01

    Results of experimental works on the study of synthesis conditions, structure and physico-chemical properties of rare earth, scandium and yttrium sulfates, have been generalized. Phase diagrams of solubility and fusibility, thermodynamic and crystallochemical characteristics, thermal stability of hydrates and anhydrous sulfates of rare earths, including normal, double (with cations of alkali and alkaline-earth metals), ternary and anion-mixed sulfates of rare earths, as well as their adducts, are considered. The state of ions of rare earths, scandium and yttrium in aqueous sulfuric acid solutions is discussed. Data on the use of rare earth sulfates are given

  1. Electrical characterization of high-pressure reactive sputtered ScOx films on silicon

    International Nuclear Information System (INIS)

    Castan, H.; Duenas, S.; Gomez, A.; Garcia, H.; Bailon, L.; Feijoo, P.C.; Toledano-Luque, M.; Prado, A. del; San Andres, E.; Lucia, M.L.

    2011-01-01

    Al/ScO x /SiN x /n-Si and Al/ScO x /SiO x /n-Si metal-insulator-semiconductor capacitors have been electrically characterized. Scandium oxide was grown by high-pressure sputtering on different substrates to study the dielectric/insulator interface quality. The substrates were silicon nitride and native silicon oxide. The use of a silicon nitride interfacial layer between the silicon substrate and the scandium oxide layer improves interface quality, as interfacial state density and defect density inside the insulator are decreased.

  2. In-depth survey report of Scoular Elevator, Salina, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    Zaebst, D.D.

    1987-06-01

    An in/depth industrial hygiene survey of exposures to phosphine during the use of aluminum phosphide was conducted as part of a survey on exposure to grain fumigants. Area monitoring and breathing-zone sampling for phosphine were conducted during the addition of aluminum phosphide to grain during turning operations; source samples and peak personal exposures were also analyzed. Major sources of personal exposure included the escape of air from the bin headspace during filling with treated grain, filling and emptying of the phosphide pellet dispenser, and infiltration from the treated grain bin and from the pellet dispenser itself into adjacent air space. Relatively good dust control was indicated by the total dust samples collected during the survey. Measures recommended by the author are in the report.

  3. Strained quantum well photovoltaic energy converter

    Science.gov (United States)

    Freundlich, Alexandre (Inventor); Renaud, Philippe (Inventor); Vilela, Mauro Francisco (Inventor); Bensaoula, Abdelhak (Inventor)

    1998-01-01

    An indium phosphide photovoltaic cell is provided where one or more quantum wells are introduced between the conventional p-conductivity and n-conductivity indium phosphide layer. The approach allows the cell to convert the light over a wider range of wavelengths than a conventional single junction cell and in particular convert efficiently transparency losses of the indium phosphide conventional cell. The approach hence may be used to increase the cell current output. A method of fabrication of photovoltaic devices is provided where ternary InAsP and InGaAs alloys are used as well material in the quantum well region and results in an increase of the cell current output.

  4. Eiperimental and thermodynamic study od curve of retrograde solidus in InP-Ge quasi-binary system

    International Nuclear Information System (INIS)

    Glazov, V.M.; Pavlova, L.M.; Perederij, L.I.

    1983-01-01

    Germanium solubility in indium phosphide at different temperatures is experimentally investigated, and it is shown that the solidus curve in the portion adjoining InP is of a retrograde character. The method of radioactive tracers has been used to determine the coefficient of germanium distribution between the liquid and solid phases at a melting point of indium phosphide. Concentration dependence of the number of electrons at indium phosphide doping with germanium is investigated, and violation of the ionization equality is shown that is explained by an amphoteric character of o.ermanium behaviour in the InP base solid solution resulting in a self-compensation effect. The retrograde solidus curve in the InP-Ge system is calculated thermodynamically with the use of model representations on the composition of solid and liquid solutions. The ionization degree of doping impurity and self-compensation effect are taken account in calculation. Good agreement of the calculated and experimental data is observed

  5. Effect of phosphorus on the swelling and precipitation behavior of austenitic stainless steels during irradiation

    International Nuclear Information System (INIS)

    Lee, E.H.; Mansur, L.K.; Rowcliffe, A.F.

    1983-01-01

    It has been observed that increasing the volume fraction of the needle-shaped iron phosphide phase in austenitic stainless steels tends to inhibit void swelling during neutron irradiation. An earlier analysis showed that this effect could not be accounted for in terms of enhanced point defect recombination at particle-matrix interfaces. The behavior of the iron phosphide phase has been further examined using dual ion beam irradiations. It was found that the particle-matrix interface serves as a site for the nucleation of a very fine dispersion of helium bubbles. It is thought that since a high number density of cavities lowers the number of helium atoms per cavity, the irradiation time for the cavities to accumulate the critical number of gas atoms for bias-driven growth is correspondingly increased. Although the phosphide phase nucleates rapidly, it eventually undergoes dissolution if either the G or Laves phase develops with increasing dose

  6. Accidental Phosphine Gas Poisoning with Fatal Myocardial Dysfunction in Two Families

    International Nuclear Information System (INIS)

    Akhtar, S.; Rehman, A.; Haque, A.; Bano, S.

    2015-01-01

    Aluminum phosphide is commonly used as a rodenticide and insecticide and is one of the most fatal poisons. The active ingredient is Phosphine gas which inhibits cytochrome oxidase and cellular oxygen utilization. The clinical symptoms are due to multiorgan involvement including cardiac toxicity which is the most common cause of mortality. Severity of clinical manifestations depends upon the amount of the gas to which a person is exposed. There is no specific antidote available. High index of suspicion and early aggressive treatment is the key to success. We report 2 cases of aluminum phosphide toxicity in 2 families due to incidental exposure after fumigation. (author)

  7. Barringerite Fe2P from Pyrometamorphic Rocks of the Hatrurim Formation, Israel

    Science.gov (United States)

    Britvin, S. N.; Murashko, M. N.; Vapnik, E.; Polekhovsky, Yu. S.; Krivovichev, S. V.

    2017-12-01

    The article provides a detailed mineralogical and crystallochemical description (including refinement of the crystal structure) of the first finding of the phosphide class mineral barringerite, Fe2P, from terrestrial pyrometamorphic rocks of the Hatrurim Formation in Israel. The mineral occurs in the association of the so-called paralavas—initially silicate—carbonate sedimentary rocks that remelted during pyrometamorphic processes at a temperature above 1000°C and at a low pressure. Questions on the genesis and crystal chemistry of barringerite are discussed in connection with another polymorphic iron phosphide, allabogdanite (Fe,Ni)2P.

  8. Trace element patterns at a non-marine cretaceous-tertiary boundary

    Science.gov (United States)

    Gilmore, J.S.; Knight, J.D.; Orth, C.J.; Pillmore, C.L.; Tschudy, R.H.

    1984-01-01

    At the fossil-pollen-defined Cretaceous-Tertiary boundary in the Raton Basin of New Mexico and Colorado, an iridium abundance anomaly and excess scandium, titanium, and chromium are associated with a thin ash or dust fallout bed (now kaolinitic clay) that was preserved in freshwater coal swamps. ?? 1984 Nature Publishing Group.

  9. The potential for economic recovery of metals from the Sillamaee site

    International Nuclear Information System (INIS)

    Davis, G.A.

    2000-01-01

    Preliminary analysis indicates that there is the potential for economic recovery of lanthanum, scandium, niobium, and strontium metals from a small portion of the Sillamaee tailings pond. There are, however, many economic and technical uncertainties that need to be resolved before a more definitive statement can be made

  10. Lightweight hydrogen-storage material Mg0.65Sc0.35D2 studied with 2H and 2H–{45Sc} MAS NMR exchange spectroscopy

    NARCIS (Netherlands)

    Srinivasan, S.; Magusin, P.C.M.M.

    2011-01-01

    Using double-quantum 2H MAS NMR with 45Sc recoupling and Bloch–Siegert compensated 2H–{45Sc} TRAPDOR we have identified the overlapping NMR signals of deuterium with and without scandium neighbors in Mg0.65Sc0.35D2, a candidate lightweight material for hydrogen storage. At room temperature we also

  11. LEWIS ACID CATALYZED FORMATION OF TETRAHYDROPYRANS IN IONIC LIQUID

    Science.gov (United States)

    Tetrahydropyrans are integral moieties in innumerable natural products and have inspired the development of a variety of different methodologies. A Prins-type cyclization involving the coupling of a homoallylic alcohol and an aldehyde in the presence of catalytic scandium triflat...

  12. Activation Analysis of Aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Brune, Dag

    1961-01-15

    An analysis of pure aluminium alloyed with magnesium was per- formed by means of gamma spectrometry , Chemical separations were not employed. The isotopes to be determined were obtained in conditions of optimum activity by suitably choosing the time of irradiation and decay. The following elements were detected and measured quantitatively: Iron, zinc, copper, gallium, manganese, chromium, scandium and hafnium.

  13. Neutron-Activation Analysis of Biological Material with High Radiation Levels

    Energy Technology Data Exchange (ETDEWEB)

    Samsahl, K

    1966-09-15

    A method has been developed for the chemical separation and subsequent gamma-spectrometric analysis of the alkali metals, the alkaline earths, the rare earths, chromium, hafnium, lanthanum, manganese, phosphorus, scandium and silver in neutron-activated biological material. The separation steps, being fully automatic, are based on a combination of ion-exchange and partition chromatography and require 40 min.

  14. Putting the bite on termites

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    An Australian program for studying and controlling termites traces the insects by feeding them a bait containing a short-lived isotope such as lanthanum-140 or scandium-46. It has been discovered that termites can live entirely above the ground. Another discovery is that colonies often occupy several shared mounds

  15. Critical metals (REE, Sc, PGE) in Ni laterites from Cuba and the Dominican Republic

    Czech Academy of Sciences Publication Activity Database

    Aiglsperger, T.; Proenza, J. A.; Lewis, J. F.; Labrador, M.; Svojtka, Martin; Rojas-Purón, A.; Longo, F.; Ďurišová, Jana

    2016-01-01

    Roč. 73, March 01 (2016), s. 127-147 ISSN 0169-1368 Institutional support: RVO:67985831 Keywords : Caribbean * Cuba * Dominican Republic * Falcondo mining area * Moa Bay mining area * Ni laterite * Platinum Group Elements * Rare Earth Elements * Scandium Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.095, year: 2016

  16. Neutron-Activation Analysis of Biological Material with High Radiation Levels

    International Nuclear Information System (INIS)

    Samsahl, K.

    1966-09-01

    A method has been developed for the chemical separation and subsequent gamma-spectrometric analysis of the alkali metals, the alkaline earths, the rare earths, chromium, hafnium, lanthanum, manganese, phosphorus, scandium and silver in neutron-activated biological material. The separation steps, being fully automatic, are based on a combination of ion-exchange and partition chromatography and require 40 min

  17. Aluminum alloy and associated anode and battery

    International Nuclear Information System (INIS)

    Tarcy, G.P.

    1990-01-01

    This patent describes an aluminum alloy. It comprises: eutectic amounts of at least two alloying elements selected from the group consisting of bismuth, cadmium, scandium, gallium, indium, lead, mercury, thallium, tin, and zinc with the balance being aluminum and the alloying elements being about 0.01 to 3.0 percent by weight of the alloy

  18. Phase composition of EhK 990-ID steel

    International Nuclear Information System (INIS)

    Rabinovich, A.V.; Milova, I.M.; Zaslavskij, Yu.B.; Neklyudov, I.M.; Chernyj, B.P.; Vanzha, A.F.; Zejdlits, M.P.; Kurasov, A.N.; Shmelev, Yu.S.

    1990-01-01

    The microstructure and phase composition of EhK99 steel have been investigated. It is shown that the scandium absolute concentration in solid solution of hot-deformed metal is directly proportional to their total content. It was established that the ratio between the scandium concentration in solid solution and the total content [Sc] ss/[Sc] s is not the function of the latter and constitutes (24.5±5.5) rel.%. The limiting scandium solubility in the EhK99 steel at temperature 1270 deg C was determined. It constitutes 0.07±0.005 mass%. In this paper proposed is the mechanism of intermetallide-and-second phase nucleation and growth during crystallization and homogenizing annealing. The recommendation for regimes of homogenizing annealing (1270 deg C, 12 hours) are given. It is shown that the homogenizing vacuum annealing may have an appreciable influence on the technique plasticity and production of good tubes of EhK99 steel with scandium content no more than 0.07wt%. 2 refs., 10 figs., 2 tabs

  19. In operando studies of ScYSZ electrolyte supported symmetric solid oxide cell by X-ray Diffraction at ESRF, ID06 Beamline

    DEFF Research Database (Denmark)

    Sierra, J. X.; Poulsen, H. F.; Jørgensen, P. S.

    Solid Oxide Cells are becoming a promising solution for sustainable and renewable power generation. Scandium doped Yttria Stabilized Zirconia is considered one of the best materials used as electrolyte because of its high ionic conductivity and great mechanical and chemical stability under operat...... evolution at different depths of the cell during operation....

  20. Mesonic atoms. Technical progress report

    International Nuclear Information System (INIS)

    Kunselman, R.

    1981-01-01

    Research on mesic atoms during 1981 is reported. This includes measurement of x-rays from pionic hydrogen and pionic deuterium; muonic K, L, and M x-ray spectra of mercury 199 and mercury 201; and pionic chromium 54, scandium 45, vanadium 51, manganese 55, and iron

  1. Sc-45 nuclear magnetic resonance analysis of precipitation in dilute Al-Sc alloys

    NARCIS (Netherlands)

    Celotto, S; Bastow, TJ

    Nuclear magnetic resonance (NMR) with Sc-45 is used to determine the solid solubility of scandium in aluminium and to follow the precipitation of Al3Sc during the ageing of an Al-0.06 at.% Sc alloy via the two fully resolved peaks, corresponding to Sc in the solid solution Al matrix and to Sc in the

  2. 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...

  3. Surface roughness and morphologic changes of zirconia: Effect of ...

    African Journals Online (AJOL)

    4-6 W/20 Hz presented significantly effect in surface roughness changes of zirconia than other surface treatments. Key words:Erbium, chromium: Yttrium, scandium, gallium, garnet laser, scanning electron .... ZrO2, (f) After sintering ZrO2 in letter “e”, (g) 2 W laser irridiation pre-sintered ZrO2, (h) After ..... Acta Odontol Scand.

  4. Ife Journal of Science - Vol 16, No 1 (2014)

    African Journals Online (AJOL)

    The effects of aluminum or scandium on the toughness, density and phase stability of iridium, platinum, rhodium and palladium · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. A. I. Popoola, O. R. Bello, 99-105 ...

  5. Orientation relationships of carlsbergite in schreibersite and kamacite in the North Chile iron meteorite

    Czech Academy of Sciences Publication Activity Database

    Nolze, G.; Wagner, G.; Neumann, R. S.; Skála, Roman; Geist, V.

    2006-01-01

    Roč. 70, č. 4 (2006), s. 373-382 ISSN 0026-461X Institutional research plan: CEZ:AV0Z30130516 Keywords : EBSD * phosphides * carlsbergite Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.064, year: 2006

  6. MMIC integration technology investigation

    Science.gov (United States)

    Kapoor, Vik J.

    1991-01-01

    Final technical report on NASA cooperative agreement NCC-167 is presented for the period March 5, 1990 to June 15, 1991. The following topics are included: (1) four to one power combiner for 20 GHz phased array antenna using RADC MMIC phase shifters; and (2) testing of indium phosphide devices.

  7. Interdigitated Back-Surface-Contact Solar Cell Modeling Using Silvaco Atlas

    Science.gov (United States)

    2015-06-01

    and Gallium Arsenide, and triple -junction cells with Indium Gallium Phosphide, Gallium Arsenide, and Germanium. Work was also done by Fotis [4] on...output power at various points on the IV curve, from [15]. ............................18 Figure 15. IV curve with the MPP. The orange area is...53 Figure 35. Simulation results of cell power output at maximum power point for varying bulk thicknesses

  8. Thermal oxidation of InP in the presence of nitrates and sulfates of the 4-th group

    International Nuclear Information System (INIS)

    Mittova, I.Ya.; Shchukarev, A.V.; Soshnikov, V.V.; Kashkarov, V.M.

    1999-01-01

    Kinetics and thermal oxidation of indium phosphide were investigated in gas phase of 4 group metal (lead and zirconium) salts. These compound promotors were determined to accelerate oxidation. The mechanism of the effect of promoter cation and anion constituents on formation of the resultant heterostructure were discussed [ru

  9. East and Central African Journal of Pharmaceutical Sciences - Vol 5 ...

    African Journals Online (AJOL)

    Investigation of Possible Antidotal Effects of Activated Charcoal, Sodium Bicarbonate, Hydrogen Peroxide and Potassium Permanganate in Zinc Phosphide Poisoning · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. CK Maitai, DK Njoroge, KO Abuga, AM Mwaura, ...

  10. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Phosphorous is treated as an impurity in conventional steels owing to segregation of phosphorous and formation of brittle phosphides along the grain boundaries. It is responsible for cold and hot shortness in wrought steels. In conventional powder metallurgy, involving compaction and sintering, high phosphorous content ...

  11. Progress in InP based photonic integration technology

    NARCIS (Netherlands)

    Smit, M.K.

    2015-01-01

    Indium Phosphide is a versatile semiconductor material that allows for integration of a broad range of components in a single chip. Basic building blocks include lasers, optical amplifiers, modulators, detectors and a variety of passive components, including wavelength demultiplexers, filters and

  12. Photoelectric properties of ITO/p(+)-p(-)-InP solar cells in linearly polarized light

    NARCIS (Netherlands)

    Botnaryuk, VM; Gorchak, LV; Raevskii, SD; Sherban, DA; Rud, VY; Rud, YV

    Indium phosphide heterostructures and transparent conducting films of wide-gap oxides have previously been used in the development of highly efficient solar cells, making it possible to bring their efficiencies up to 18% [M, M. Koltun, Optics and Metrology of Solar Cells [in Russian], Nauka, Moscow

  13. All-optical signal processing at 10 GHz using a photonic crystal molecule

    Energy Technology Data Exchange (ETDEWEB)

    Combrié, Sylvain; Lehoucq, Gaëlle; Junay, Alexandra; De Rossi, Alfredo, E-mail: alfredo.derossi@thalesgroup.com [Thales Research and Technology, 1 Avenue A. Fresnel, 91767 Palaiseau (France); Malaguti, Stefania; Bellanca, Gaetano; Trillo, Stefano [Department of Engineering, Università di Ferrara, v. Saragat 1, 44122 Ferrara (Italy); Ménager, Loic [Thales Systèmes Aeroportés, 2 Av. Gay Lussac, 78851 Elancourt (France); Peter Reithmaier, Johann [Institute of Nanostructure Technologies and Analytics, CINSaT, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel (Germany)

    2013-11-04

    We report on 10 GHz operation of an all-optical gate based on an Indium Phosphide Photonic Crystal Molecule. Wavelength conversion and all-optical mixing of microwave signals are demonstrated using the 2 mW output of a mode locked diode laser. The spectral separation of the optical pump and signal is crucial in suppressing optical cross-talk.

  14. Atomic Force Microscopy | Materials Science | NREL

    Science.gov (United States)

    as height, optical absorption, or magnetism using a probe close to the sample; this black, gray, and sample made of gallium phosphide on silicon and appears as yellow and red rice-like clusters. Right: An image features gray and white areas apparently overlapping on a black background, and it was obtained

  15. Palladium nanoparticles on InP for hydrogen detection

    Czech Academy of Sciences Publication Activity Database

    Černohorský, Ondřej; Žďánský, Karel; Zavadil, Jiří; Kacerovský, Pavel; Piksová, K.

    2011-01-01

    Roč. 6, č. 410 (2011), s. 4101-4104 ISSN 1931-7573 R&D Projects: GA AV ČR(CZ) KAN401220801; GA ČR GA102/09/1037 Institutional research plan: CEZ:AV0Z20670512 Keywords : palladium * indium phosphide Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.726, year: 2011

  16. On-chip patch antenna on InP substrate for short-range wireless communication at 140 GHz

    DEFF Research Database (Denmark)

    Dong, Yunfeng; Johansen, Tom Keinicke; Zhurbenko, Vitaliy

    2017-01-01

    This paper presents the design of an on-chip patch antenna on indium phosphide (InP) substrate for short-range wireless communication at 140 GHz. The antenna shows a simulated gain of 5.3 dBi with 23% bandwidth at 140 GHz and it can be used for either direct chip-to-chip communication or chip...

  17. High-resolution synchrotron diffraction study of porous buffer InP(001) layers

    Czech Academy of Sciences Publication Activity Database

    Lomov, A. A.; Punegov, V. I.; Nohavica, Dušan; Chuev, M.A.; Vasiliev, A.L.; Novikov, D. V.

    2014-01-01

    Roč. 47, č. 5 (2014), s. 1614-1625 ISSN 0021-8898 Institutional support: RVO:67985882 Keywords : porous layers * X-ray reciprocal space mapping * indium phosphide Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.720, year: 2014

  18. Demography of black-tailed prairie dog populations reoccupying sites treated with rodenticide

    Science.gov (United States)

    R. P. Cincotta; Daniel W. Uresk; R. M. Hansen

    1987-01-01

    A rodenticide, zinc phosphide, was applied to remove black-tailed prairie dogs (Cynomys ludovicianus) from 6 haofa prairie dog colony in southwestern South Dakota. Another adjacent 6 ha was left untreated. The removal experiment was repeated two consecutive years. Contingency table analysis showed that the resultant population was not homogeneous;...

  19. Mechanical devices for aligning optical fibers using elastic metal-deformation techniques

    NARCIS (Netherlands)

    van Zantvoort, J.H.C.; Plukker, S.G.L.; Kuindersma, P.I.; Mekonnen, K.A.; de Waardt, H.

    2016-01-01

    We designed and realized two different mechanical devices for aligning standard lensed telecom fibers to indium-phosphide-based photonic integrated circuits (PICs). The first device (Device A) can align one fiber in three degrees of freedom, while the second device (Device B) can align two fiber

  20. Electrical and thermal characterization of single and multi-finger InP DHBTs

    DEFF Research Database (Denmark)

    Midili, Virginio; Nodjiadjim, V.; Johansen, Tom Keinicke

    2015-01-01

    This paper presents the characterization of single and multi-finger Indium Phosphide Double Heterojunction Bipolar transistors (InP DHBTs). It is used as the starting point for technology optimization. Safe Operating Area (SOA) and small signal AC parameters are investigated along with thermal ch...

  1. Design procedure for millimeter-wave InP DHBT stacked power amplifiers

    DEFF Research Database (Denmark)

    Squartecchia, Michele; Johansen, Tom Keinicke; Midili, Virginio

    2015-01-01

    The stacked-transistor concept for power amplifiers (PA) has been investigated in this work. Specifically, this architecture has been applied in the design of millimeter-wave monolithic microwave integrated circuits (MMICs) using indium phosphide (InP) double heterojunction bipolar transistors...

  2. 40 CFR 152.175 - Pesticides classified for restricted use.

    Science.gov (United States)

    2010-07-01

    ...% and less All uses (domestic and nondomestic) Unclassified Paraquat (dichloride) and paraquat bis... subsoil ......do Do. ......do All subsoil uses Unclassified Sulfotepp Sprays and smoke generators All uses Restricted Inhalation hazard to humans. Zinc Phosphide All formulations 2% and less All domestic uses and non...

  3. Phosphorus-based compounds for EUV multilayer optics materials

    NARCIS (Netherlands)

    Medvedev, Viacheslav; Yakshin, Andrey; van de Kruijs, Robbert Wilhelmus Elisabeth; Bijkerk, Frederik

    2015-01-01

    We have evaluated the prospects of phosphorus-based compounds in extreme ultraviolet multilayer optics. Boron phosphide (BP) is suggested to be used as a spacer material in reflective multilayer optics operating just above the L-photoabsorption edge of P (λ ≈9.2 nm). Mo, Ag, Ru, Rh, and Pd were

  4. Label swapper device for spectral amplitude coded optical packet networks monolithically integrated on InP

    NARCIS (Netherlands)

    Muñoz, P.; García-Olcina, R.; Habib, C.; Chen, L.R.; Leijtens, X.J.M.; Vries, de T.; Robbins, D.J.; Capmany, J.

    2011-01-01

    In this paper the design, fabrication and experimental characterization of an spectral amplitude coded (SAC) optical label swapper monolithically integrated on Indium Phosphide (InP) is presented. The device has a footprint of 4.8x1.5 mm2 and is able to perform label swapping operations required in

  5. Poultry egg components as cereal bait additives for enhancing rodenticide based control success and trap index of house rat, Rattus rattus

    Directory of Open Access Journals (Sweden)

    Neena Singla

    2014-05-01

    Conclusions: Present data support the use of 2% egg albumin and egg shell powder in cereal bait to enhance acceptance and efficacy of 2% zinc phosphide bait against R. rattus. This may further help in checking the spread of rodent borne diseases to animals and humans.

  6. Sustainable Phosphorus Chemistry: A Silylphosphide Synthon for the Generation of Value-Added Phosphorus Chemicals.

    Science.gov (United States)

    Slootweg, J Chris

    2018-05-07

    Avoiding white phosphorus: Cummins and Geeson have recently described the conversion of phosphoric acid into the novel bis(trichlorosilyl)phosphide anion, which serves as a key intermediate in the synthesis of organophosphines, hexafluorophosphate, and phosphine gas in a reaction sequence that does not rely on white phosphorus. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Rague-Like FeP Nanocrystal Assembly on Carbon Cloth: An Exceptionally Efficient and Stable Cathode for Hydrogen Evolution

    KAUST Repository

    Yang, Xiulin

    2015-05-25

    There is a strong demand to replace expensive Pt catalysts with cheap metal sulfides or phosphides for hydrogen generation in water electrolysis. The earth-abundant Fe can be electroplated on carbon cloth (CC) to form high surface area rague-like FeOOH assembly. Subsequent gas phase phosphidation converts the FeOOH to FeP or FeP2 and the morphology of the crystal assembly is controlled by the phosphidation temperature. The FeP prepared at 250 oC presents lower crystallinity and those prepared at higher temperatures 400 oC and 500 oC possess higher crystallinity but lower surface area. The phosphidation at 300 oC produces nanocrystalline FeP and preserves the high-surface area morphology; thus it exhibits the highest HER efficiency in 0.5 M H2SO4; i.e. the required overpotential to reach 10 and 20 mA/cm2 is 34 and 43 mV respectively. These values are lowest among the reported non-precious metal phosphides on CC. The Tafel slope for the FeP prepared at 300 oC is around 29.2 mV/dec comparable to that of Pt/CC, indicating that the hydrogen evolution for our best FeP is limited by Tafel reaction (same as Pt). Importantly, the FeP/CC catalyst exhibits much better stability in a wide range working current density (up to 1 V/cm2), suggesting that it is a promising replacement of Pt for HER.

  8. Rague-Like FeP Nanocrystal Assembly on Carbon Cloth: An Exceptionally Efficient and Stable Cathode for Hydrogen Evolution

    KAUST Repository

    Yang, Xiulin; Lu, Ang-Yu; Zhu, Yihan; Min, Shixiong; Hedhili, Mohamed N.; Han, Yu; Huang, Kuo-Wei; Li, Lain-Jong

    2015-01-01

    There is a strong demand to replace expensive Pt catalysts with cheap metal sulfides or phosphides for hydrogen generation in water electrolysis. The earth-abundant Fe can be electroplated on carbon cloth (CC) to form high surface area rague-like FeOOH assembly. Subsequent gas phase phosphidation converts the FeOOH to FeP or FeP2 and the morphology of the crystal assembly is controlled by the phosphidation temperature. The FeP prepared at 250 oC presents lower crystallinity and those prepared at higher temperatures 400 oC and 500 oC possess higher crystallinity but lower surface area. The phosphidation at 300 oC produces nanocrystalline FeP and preserves the high-surface area morphology; thus it exhibits the highest HER efficiency in 0.5 M H2SO4; i.e. the required overpotential to reach 10 and 20 mA/cm2 is 34 and 43 mV respectively. These values are lowest among the reported non-precious metal phosphides on CC. The Tafel slope for the FeP prepared at 300 oC is around 29.2 mV/dec comparable to that of Pt/CC, indicating that the hydrogen evolution for our best FeP is limited by Tafel reaction (same as Pt). Importantly, the FeP/CC catalyst exhibits much better stability in a wide range working current density (up to 1 V/cm2), suggesting that it is a promising replacement of Pt for HER.

  9. Reducing the stochasticity of crystal nucleation to enable subnanosecond memory writing

    Science.gov (United States)

    Rao, Feng; Ding, Keyuan; Zhou, Yuxing; Zheng, Yonghui; Xia, Mengjiao; Lv, Shilong; Song, Zhitang; Feng, Songlin; Ronneberger, Ider; Mazzarello, Riccardo; Zhang, Wei; Ma, Evan

    2017-12-01

    Operation speed is a key challenge in phase-change random-access memory (PCRAM) technology, especially for achieving subnanosecond high-speed cache memory. Commercialized PCRAM products are limited by the tens of nanoseconds writing speed, originating from the stochastic crystal nucleation during the crystallization of amorphous germanium antimony telluride (Ge2Sb2Te5). Here, we demonstrate an alloying strategy to speed up the crystallization kinetics. The scandium antimony telluride (Sc0.2Sb2Te3) compound that we designed allows a writing speed of only 700 picoseconds without preprogramming in a large conventional PCRAM device. This ultrafast crystallization stems from the reduced stochasticity of nucleation through geometrically matched and robust scandium telluride (ScTe) chemical bonds that stabilize crystal precursors in the amorphous state. Controlling nucleation through alloy design paves the way for the development of cache-type PCRAM technology to boost the working efficiency of computing systems.

  10. Experimental study of the x-ray transitions in the heliumlike isoelectronic sequence

    International Nuclear Information System (INIS)

    Beiersdorfer, P.; Bitter, M.; von Goeler, S.; Hill, K.W.

    1989-05-01

    The wavelengths of the transition 1s2p 1 P 1 → 1s 2 1 S 0 in heliumlike potassium, scandium, titanium, vanadium, chromium, and iron have been measured with an experimental precision of Δλ/λ ∼ 1/20,000. The data typically agree within error bars with recent theoretical predictions which include quantum electrodynamical corrections. However, the comparison shows that there are systematic differences between data and predictions, which indicate a need to include additional corrections in the calculations. In particular, it is found that the experimental wavelengths are consistently shorter than the calculated values by amounts which depend on the particular theoretical prediction used in the comparison. Measurements of the wavelengths of Δn ≥ 2 x-ray transitions in heliumlike argon, scandium, titanium, vanadium, chromium, and iron are also presented. 42 refs., 8 figs., 2 tabs

  11. Synthesis and crystal structure of the first Sc-Nb-O-N phases

    Energy Technology Data Exchange (ETDEWEB)

    Orthmann, Steven; Lerch, Martin [Institut fuer Chemie, Technische Universitaet Berlin (Germany)

    2017-11-17

    Synthesis of phase-pure materials in the system Sc-Nb-O-N is challenging. In this contribution we report on the preparation of the first scandium niobium oxide nitrides via reaction of water-saturated gaseous ammonia or an ammonia-oxygen mixture with amorphous scandium niobium oxides. Two new phases were obtained: rutile-type ScNb{sub 4}O{sub 7}N{sub 3}, which crystallizes in space group P4{sub 2}/mnm, and an anion-deficient fluorite-type Sc{sub 2}Nb(O,N,⬜){sub 6} phase crystallizing in space group Fm anti 3m. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. The ternary systems Sc-Sm(Dy)-Si at 870 K

    International Nuclear Information System (INIS)

    Kotur, B.Ya.; Mokra, I.Ya.; Toporinskij, A.Ya.

    1991-01-01

    Isothermal cross sections of the ternary systems Sc-Sm-Si and Sc-Dy-Si at 870 K have been plotted. Investigation of scandium and disprosium in ternary systems have been examined by X-ray diffraction and microstructure analysis. Besides literary data on binary systems Sc-Si, Sm-Si, Dy-Si have been used. Formation of limited (Sc-Sm-Si, Sc-Dy-Si) and continuous (Sc-Dy-Si) solid solutions based on bisilicides of Sc and Sm(Dy) is discovered. Two and five ternary compounds in Sc-Sm-Si and Sc-Dy-Si systems have been determined and their crystal structure has been established. When investigating of Sc-(rare earth element)-Si ternary systems and should take into account the specific interaction of scandium and samarium with REE

  13. Investigation of Sc(3) state in nonaqueous solutions by the 45Sc NMR method of high permission

    International Nuclear Information System (INIS)

    Buslaev, Yu.A.; Kirakosyan, G.A.; Tarasov, V.P.

    1980-01-01

    The ScCl 3 + CH 3 CN and ScCl 3 + KNCS + CH 3 CN solutions have been studied by a high-resolution NMR 45 Sc method. It has been estimated that in acetonitrile solutions, with competing ligands of Cl - and NCS - being available, hexacoordination Sc(3) complexes of various compositions are formed, and solvent molecules also take part in formation of the coordination sphere of scandium. Chemical shifts in NMR 45 Sc signals depend linearly on the number of chlor- or NCS - ions bound to scandium(3). This made it possible to determine the value of chemical shifts in signals of all 28 potential complexes formed in a system with three competing ligands

  14. Radiotracer investigations for sediment transport in ports of India

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Goswami, Sunil; Singh, Gursharan

    2013-01-01

    The knowledge of mixing and transport of sediments in coastal region is of vital importance for evaluating suitability of dumping site for dredged sediments produced during maintenance of shipping channels, expansion of existing projects and construction of new projects. Gamma-emitting radiotracers are commonly used for investigation of movement of sediments on seabed using Scandium-46 (scandium glass powder) as radiotracer. The radiotracer is injected on seabed at a desired location and its movement followed over a period of time using waterproof NaI(Tl) scintillation detectors. The recorded data is analyzed to obtain transport parameters and utilized for assessing the suitability of the dumping sites and optimization of the dredging operations. About 70 large-scale investigations have been carried out in different ports in India leading to significant economical benefits to the Ports. Present paper discusses various aspects of the radiotracer technique for sediment transport, methodology of data analysis and a specific case study. (author)

  15. Trace elements and essential oil composition in chemotypes of the aromatic plant Origanum vulgare

    International Nuclear Information System (INIS)

    Kanias, G.D.

    1998-01-01

    Trace elements, essential oil yield and its percentage composition were determined by neutron activation analysis, hydrodistillation and gas chromatography in two chemotypes of Origanum vulgare L. cultivated in the same field. Statistical tests such as analysis of variance, correlation coefficient, t-test, and multiple correlation were applied. The results showed that the samples contain the highest recorded oil yield for aromatic plants. Also, there is a statistically significant difference between the chemotypes of the plant not only in the predominant compound but in a number of other components. Iron, chromium and scandium showed a negative significant correlation with carvacrol and a positive one with thymol. Europium shows characteristic correlations with chromium, cobalt, iron and scandium within each chemotype of the plant. These correlations could make probable a role of this element in the biosynthesis of the predominant compounds. (author)

  16. Obsidian sources characterized by neutron-activation analysis.

    Science.gov (United States)

    Gordus, A A; Wright, G A; Griffin, J B

    1968-07-26

    Concentrations of elements such as manganese, scandium, lanthanum, rubidium, samarium, barium, and zirconium in obsidian samples from different flows show ranges of 1000 percent or more, whereas the variation in element content in obsidian samples from a single flow appears to be less than 40 percent. Neutron-activation analysis of these elements, as well as of sodium and iron, provides a means of identifying the geologic source of an archeological artifact of obsidian.

  17. Evaluated phase diagrams of binary metal-tellurium systems of the D-block transition elements

    International Nuclear Information System (INIS)

    Chattopadhyay, G.; Bharadwaj, S.R.

    1989-01-01

    The binary phase diagrams of metal-tellurium systems for twenty seven d-block transition elements have been critically evaluated. Complete phase diagrams are presented for the elements, chromium, manganese, iron, cobalt, nickel, copper, molybdenum, palladium, silver, lanthanum, platinum and gold, whereas, for scandium, titanium, vanadium, yttrium, zirconium, niobium, technitium, ruthenium, rhodium, hafnium, tantalum, tungsten , rhenium, osmium and iridium, the phase diagrams are incomplete and tentative. (author). 20 refs., 27 tabs., 27 figs

  18. Determination of line broadening constants in high pressure discharge lamps

    International Nuclear Information System (INIS)

    Weiss, M; Schubert, H; Meier, S; Born, M; Reiter, D; Stroesser, M

    2005-01-01

    A numerical model of the radiative transfer in high pressure metal halide discharge lamps is used to determine line broadening parameters for atomic scandium lines. The determined broadening constants are in qualitative agreement with theoretical estimates in many cases, but significant deviations exist. The data obtained from this paper can, therefore, be used to further improve modelling of radiative contributions to the energy balance in such types of discharge lamps

  19. 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

  20. Antibodies and isotopes, a chemical approach to tumour targeting

    International Nuclear Information System (INIS)

    Vaughan, A.T.M.; Yankuba, S.C.S.; Anderson, P.

    1986-01-01

    In this study, scandium-47 and yttrium-90 have been used as representatives of potential cytotoxic labels. Both isotopes have a high yield of energetic beta particles and half-lives of the same order as indium-111. In addition they are both members of Group III and so may be used as a base for chemical comparisons in the future with radiotoxic isotopes from other chemical groups