Sample records for uut ge sn

  1. Characteristics of Sn segregation in Ge/GeSn heterostructures

    SciTech Connect (OSTI)

    Li, H.; Chang, C.; Chen, T. P.; Cheng, H. H., E-mail: hhcheng@ntu.edu.tw [Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Shi, Z. W.; Chen, H. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-10-13T23:59:59.000Z

    We report an investigation of Sn segregation in Ge/GeSn heterostructures occurred during the growth by molecular beam epitaxy. The measured Sn profile in the Ge layer shows that: (a) the Sn concentration decreases rapidly near the Ge/GeSn interface, and (b) when moving away from the interface, the Sn concentration reduced with a much slower rate. The 1/e decay lengths of the present system are much longer than those of the conventional group IV system of Ge segregation in the Si overlayer because of the smaller kinetic potential as modeled by a self-limited two-state exchange scheme. The demonstration of the Sn segregation shows the material characteristics of the heterostructure, which are needed for the investigation of its optical properties.

  2. A Mossbauer spectroscopy study of nanoscale GeSn dispersions prepared by ball milling

    E-Print Network [OSTI]

    Boolchand, Punit

    A Mo¨ssbauer spectroscopy study of nanoscale Ge­Sn dispersions prepared by ball milling P by 119 Sn Mo¨ssbauer spectroscopy. The Mo¨ssbauer measurements in general reveal two sites for the Sn of the Sn was detected by Mo¨ssbauer spectroscopy at Sn-poor concentrations (x # 0.10) when the milling vial

  3. Formation of non-substitutional ?-Sn defects in Ge{sub 1?x}Sn{sub x} alloys

    SciTech Connect (OSTI)

    Fuhr, J. D. [Centro Atómico Bariloche-CNEA and CONICET, Av. Bustillo 9500, R8402AGP Bariloche (Argentina); Instituto Balseiro, Univ. Nac. de Cuyo and CNEA, 8400 Bariloche (Argentina); Ventura, C. I. [Centro Atómico Bariloche-CNEA and CONICET, Av. Bustillo 9500, R8402AGP Bariloche (Argentina); Sede Andina, Univ. Nac. de Río Negro, 8400 Bariloche (Argentina); Barrio, R. A. [Instituto de Física, U.N.A.M., 01000 Mexico, D.F. (Mexico)

    2013-11-21T23:59:59.000Z

    Although group IV semiconductor alloys are expected to form substitutionally, in Ge{sub 1?x}Sn{sub x} this is true only for low concentrations (x?Sn), consisting of a single Sn atom in the center of a Ge divacancy, which may account for the segregation of Sn at large x. Afterwards, the existence of this defect was confirmed experimentally. In this paper we study the local environment and the interactions of the substitutional defect (?-Sn), the vacancy in Ge, and the ?-Sn defect by performing extensive numerical ab initio calculations. Our results confirm that a ?-Sn defect can be formed by natural diffusion of a vacancy around the substitutional ?-Sn defect, since the energy barrier for the process is very small.

  4. Lattice constant and substitutional composition of GeSn alloys grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Bhargava, Nupur; Coppinger, Matthew; Prakash Gupta, Jay; Kolodzey, James [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States)] [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States); Wielunski, Leszek [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 (United States)] [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 (United States)

    2013-07-22T23:59:59.000Z

    Single crystal epitaxial Ge{sub 1?x}Sn{sub x} alloys with atomic fractions of tin up to x = 0.145 were grown by solid source molecular beam epitaxy on Ge (001) substrates. The Ge{sub 1?x}Sn{sub x} alloys formed high quality, coherent, strained layers at growth temperatures below 250 °C, as shown by high resolution X-ray diffraction. The amount of Sn that was on lattice sites, as determined by Rutherford backscattering spectrometry channeling, was found to be above 90% substitutional in all alloys. The degree of strain and the dependence of the effective unstrained bulk lattice constant of Ge{sub 1?x}Sn{sub x} alloys versus the composition of Sn have been determined.

  5. GeSn-based p-i-n photodiodes with strained active layer on a Si wafer

    SciTech Connect (OSTI)

    Tseng, H. H.; Li, H.; Mashanov, V.; Yang, Y. J.; Cheng, H. H., E-mail: hhcheng@ntu.edu.tw [Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 106, Taiwan (China); Chang, G. E. [Department of Mechanical Engineering, and Advanced Institute of Manufacturing with High-tech Innovations, National Chung Cheng University, Chiayi County 62102, Taiwan (China)] [Department of Mechanical Engineering, and Advanced Institute of Manufacturing with High-tech Innovations, National Chung Cheng University, Chiayi County 62102, Taiwan (China); Soref, R. A.; Sun, G. [Department of Physics, University of Massachusetts Boston, Boston, Massachusetts 02125 (United States)] [Department of Physics, University of Massachusetts Boston, Boston, Massachusetts 02125 (United States)

    2013-12-02T23:59:59.000Z

    We report an investigation of GeSn-based p-i-n photodiodes with an active GeSn layer that is almost fully strained. The results show that (a) the response of the Ge/GeSn/Ge heterojunction photodiodes is stronger than that of the reference Ge-based photodiodes at photon energies above the 0.8 eV direct bandgap of bulk Ge (<1.55??m), and (b) the optical response extends to lower energy regions (1.55–1.80??m wavelengths) as characterized by the strained GeSn bandgap. A cusp-like spectral characteristic is observed for samples with high Sn contents, which is attributed to the significant strain-induced energy splitting of heavy and light hole bands. This work represents a step forward in developing GeSn-based infrared photodetectors.

  6. Interaction of Sn atoms with defects introduced by ion implantation in Ge substrate

    SciTech Connect (OSTI)

    Taoka, Noriyuki, E-mail: ntaoka@alice.xtal.nagoya-u.ac.jp; Fukudome, Motoshi; Takeuchi, Wakana; Arahira, Takamitsu; Sakashita, Mitsuo; Nakatsuka, Osamu; Zaima, Shigeaki [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2014-05-07T23:59:59.000Z

    The interaction of Sn atoms with defects induced by Sn implantation of Ge substrates with antimony (Sb) as an n-type dopant and the impact of H{sub 2} annealing on these defects were investigated by comparison with defects induced by Ge self-implantation. In the Ge samples implanted with either Sn or Ge, and annealed at temperatures of less than 200?°C, divacancies, Sb-vacancy complexes with single or double acceptor-like states, and defects related to Sb and interstitial Ge atoms were present. On the other hand, after annealing at 500?°C in an N{sub 2} or H{sub 2} atmosphere, defects with different structures were observed in the Sn-implanted samples by deep level transition spectroscopy. The energy levels of the defects were 0.33?eV from the conduction band minimum and 0.55?eV from the valence band maximum. From the capacitance-voltage (C-V) characteristics, interaction between Sn atoms and defects after annealing at 500?°C was observed. The effect of H{sub 2} annealing at around 200?°C was observed in the C-V characteristics, which can be attributed to hydrogen passivation, and this effect was observed in both the Ge- and Sn-implanted samples. These results suggest the presence of defects that interact with Sn or hydrogen atoms. This indicates the possibility of defect control in Ge substrates by Sn or hydrogen incorporation. Such defect control could yield high-performance Ge-based devices.

  7. Study on the Ge{sub 1?x}Sn{sub x}/HfO{sub 2} interface and its impacts on Ge{sub 1?x}Sn{sub x} tunneling transistor

    SciTech Connect (OSTI)

    Qiu, Yingxin; Wang, Runsheng, E-mail: ruhuang@pku.edu.cn, E-mail: r.wang@pku.edu.cn; Huang, Qianqian; Huang, Ru, E-mail: ruhuang@pku.edu.cn, E-mail: r.wang@pku.edu.cn [Key Laboratory of Microelectronic Devices and Circuits, Institute of Microelectronics, Peking University, Beijing 100871 (China)

    2014-06-21T23:59:59.000Z

    In this paper, we employ first-principle calculation to investigate the Ge{sub 1?x}Sn{sub x}/HfO{sub 2} interface, and then evaluate its impacts on Ge{sub 1?x}Sn{sub x} tunneling field-effect transistor (TFET). First-principle calculations of Ge{sub 1?x}Sn{sub x}/HfO{sub 2} interfaces in the oxygen-rich process atmosphere indicate that the interface states originate from the Ge and Sn dangling bond, rather than Hf-bond. The total density of state shows that there are more interface states in the semiconductor bandgap with increasing Sn fraction. By further incorporating the material and interface parameters from density functional theory calculation into advanced device simulation, the electrical characteristics of Ge{sub 1?x}Sn{sub x} TFET are investigated. Removing the Sn atom from the first atom layer of Ge{sub 1?x}Sn{sub x} in device processes is found to be beneficial to reduce the degradations. For the degradation mechanisms, the trap-assisted-tunneling is the dominant mechanism at the low Sn fraction, and enhanced Shockley-Read-Hall recombination induced by traps becomes the dominant mechanism with increasing Sn fraction. The results are helpful for the interface optimization of Ge{sub 1?x}Sn{sub x} TFET.

  8. Ge{sub 1-y}Sn{sub y} (y = 0.01-0.10) alloys on Ge-buffered Si: Synthesis, microstructure, and optical properties

    SciTech Connect (OSTI)

    Senaratne, C. L.; Kouvetakis, J. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States); Gallagher, J. D.; Jiang, Liying; Smith, D. J.; Menéndez, J. [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States); Aoki, Toshihiro [LeRoy Eyring Center for Solid State Science, Arizona State University, Tempe, Arizona 85287-1704 (United States)

    2014-10-07T23:59:59.000Z

    Novel hydride chemistries are employed to deposit light-emitting Ge{sub 1-y}Sn{sub y} alloys with y ? 0.1 by Ultra-High Vacuum Chemical Vapor Deposition (UHV-CVD) on Ge-buffered Si wafers. The properties of the resultant materials are systematically compared with similar alloys grown directly on Si wafers. The fundamental difference between the two systems is a fivefold (and higher) decrease in lattice mismatch between film and virtual substrate, allowing direct integration of bulk-like crystals with planar surfaces and relatively low dislocation densities. For y ? 0.06, the CVD precursors used were digermane Ge?H? and deuterated stannane SnD?. For y ? 0.06, the Ge precursor was changed to trigermane Ge?H?, whose higher reactivity enabled the fabrication of supersaturated samples with the target film parameters. In all cases, the Ge wafers were produced using tetragermane Ge?H?? as the Ge source. The photoluminescence intensity from Ge{sub 1–y}Sn{sub y}/Ge films is expected to increase relative to Ge{sub 1–y}Sn{sub y}/Si due to the less defected interface with the virtual substrate. However, while Ge{sub 1–y}Sn{sub y}/Si films are largely relaxed, a significant amount of compressive strain may be present in the Ge{sub 1–y}Sn{sub y}/Ge case. This compressive strain can reduce the emission intensity by increasing the separation between the direct and indirect edges. In this context, it is shown here that the proposed CVD approach to Ge{sub 1–y}Sn{sub y}/Ge makes it possible to approach film thicknesses of about 1 ?m, for which the strain is mostly relaxed and the photoluminescence intensity increases by one order of magnitude relative to Ge{sub 1–y}Sn{sub y}/Si films. The observed strain relaxation is shown to be consistent with predictions from strain-relaxation models first developed for the Si{sub 1–x}Ge{sub x}/Si system. The defect structure and atomic distributions in the films are studied in detail using advanced electron-microscopy techniques, including aberration corrected STEM imaging and EELS mapping of the average diamond–cubic lattice.

  9. Large grain growth of Ge-rich Ge{sub 1?x}Sn{sub x} (x???0.02) on insulating surfaces using pulsed laser annealing in flowing water

    SciTech Connect (OSTI)

    Kurosawa, Masashi, E-mail: kurosawa@alice.xtal.nagoya-u.ac.jp [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); JSPS, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Taoka, Noriyuki; Nakatsuka, Osamu; Zaima, Shigeaki [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Ikenoue, Hiroshi [Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan)

    2014-02-10T23:59:59.000Z

    We investigate Sn incorporation effects on the growth characteristics of Ge-rich Ge{sub 1?x}Sn{sub x} (x?Sn content of 2%, Sn atoms within the GeSn layers play a role in preventing ablation and aggregation of the layers during these PLA. Raman and electron backscatter diffraction measurements demonstrate achievement of large-grain (?800?nm?) growth of Ge{sub 0.98}Sn{sub 0.02} polycrystals by using PLA in water. These polycrystals also show a tensile-strain of ?0.68%. This result opens up the possibility for developing GeSn-based devices fabricated on flexible substrates as well as Si platforms.

  10. Structure and magnetism in strained Ge{sub 1-x-y}Sn{sub x}Mn{sub y} films grown on Ge(001) by low temperature molecular beam epitaxy

    SciTech Connect (OSTI)

    Prestat, E. [INAC, SP2M, CEA and Universite Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble (France); Karlsruher Institut fuer Technologie (KIT), Laboratorium fuer Elektronenmikroskopie, D-76128 Karlsruhe (Germany); Barski, A.; Bellet-Amalric, E.; Morel, R.; Tainoff, D.; Jain, A.; Porret, C.; Bayle-Guillemaud, P.; Jamet, M. [INAC, SP2M, CEA and Universite Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble (France); Jacquot, J.-F. [INAC, SCIB, CEA and Universite Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble (France)

    2013-07-01T23:59:59.000Z

    In this letter, we study the structural and magnetic properties of Ge{sub 1-x-y}Sn{sub x}Mn{sub y} films grown on Ge(001) by low temperature molecular beam epitaxy using X-ray diffraction, high resolution transmission electron microscopy, and superconducting quantum interference device. Like in Mn doped Ge films, Mn atoms diffuse during the growth and aggregate into vertically aligned Mn-rich nanocolumns of a few nanometers in diameter. Transmission electron microscopy observations in plane view clearly indicate that the Sn incorporation is not uniform with concentration in Mn rich vertical nanocolumns lower than the detection limit of electron energy loss spectroscopy. The matrix exhibits a GeSn solid solution while there is a Sn-rich GeSn shell around GeMn nanocolumns. The magnetization in Ge{sub 1-x-y}Sn{sub x}Mn{sub y} layers is higher than in Ge{sub 1-x}Mn{sub x} films. This magnetic moment enhancement in Ge{sub 1-x-y}Sn{sub x}Mn{sub y} is probably related to the modification of the electronic structure of Mn atoms in the nanocolumns by the Sn-rich shell, which is formed around the nanocolumns.

  11. Band alignment at interfaces of amorphous Al{sub 2}O{sub 3} with Ge{sub 1?x}Sn{sub x}- and strained Ge-based channels

    SciTech Connect (OSTI)

    Chou, H.-Y.; Afanas'ev, V. V., E-mail: valeri.afanasiev@fys.kuleuven.be; Houssa, M.; Stesmans, A. [Department of Physics, University of Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Vincent, B.; Gencarelli, F.; Shimura, Y.; Merckling, C.; Loo, R. [Imec, Kapeldreef 75, B-3001 Leuven (Belgium); Nakatsuka, O.; Zaima, S. [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2014-05-19T23:59:59.000Z

    Spectroscopy of internal photoemission of electrons from Ge and Ge{sub 1?x}Sn{sub x} (x???0.08) alloys into amorphous Al{sub 2}O{sub 3} is used to evaluate the energy of the semiconductor valence band top. It is found that in Ge and Ge{sub 1?x}Sn{sub x} the valence bands are aligned within the measurement accuracy (±0.05?eV) irrespective of the strain imposed on the semiconductor or by the kind of passivating inter-layer applied between the semiconductor and alumina. This indicates that the Ge{sub 1?x}Sn{sub x}-stressor approach may be useful for strain engineering in p-channel Ge metal-oxide-semiconductor transistors.

  12. In search of high performance anode materials for Mg batteries: computational studies of Mg in Ge, Si, and Sn

    E-Print Network [OSTI]

    Malyi, Oleksandr I; Manzhos, Sergei; 10.1016/j.jpowsour.2013.01.114

    2013-01-01T23:59:59.000Z

    We present ab initio studies of structures, energetics, and diffusion properties of Mg in Si, Ge, and Sn diamond structures to evaluate their potential as insertion type anode materials for Mg batteries. We show that Si could provide the highest specific capacities (3817 mAh g-1) and the lowest average insertion voltage (~0.15 eV vs. Mg) for Mg storage. Nevertheless, due to its significant percent lattice expansion (~216%) and slow Mg diffusion, Sn and Ge are more attractive; both anodes have lower lattice expansions (~120 % and ~178 %, respectively) and diffusion barriers (~0.50 and ~0.70 eV, respectively for single-Mg diffusion) than Si. We show that Mg-Mg interactions at different stages of charging can decrease significantly the diffusion barrier compared to the single atom diffusion, by up to 0.55 eV.

  13. Sr{sub 7}Ge{sub 6}, Ba{sub 7}Ge{sub 6} and Ba{sub 3}Sn{sub 2} -Three new binary compounds containing dumbbells and four-membered chains of tetrel atoms with considerable Ge-Ge {pi}-bonding character

    SciTech Connect (OSTI)

    Siggelkow, Lisa; Hlukhyy, Viktor [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85747 Garching (Germany); Faessler, Thomas F., E-mail: thomas.faessler@lrz.tum.de [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85747 Garching (Germany)

    2012-07-15T23:59:59.000Z

    The germanides Sr{sub 7}Ge{sub 6} and Ba{sub 7}Ge{sub 6} as well as the stannide Ba{sub 3}Sn{sub 2} were prepared by arc melting and annealing in welded tantalum ampoules using induction as well as resistance furnaces. The compounds were investigated by powder and single crystal X-ray diffraction. Sr{sub 7}Ge{sub 6} and Ba{sub 7}Ge{sub 6} crystallize in the Ca{sub 7}Sn{sub 6} structure type (space group Pmna, Z=4: a=7.777(2) A, b=23.595(4) A, c=8.563(2) A, wR{sub 2}=0.081 (all data), 2175 independent reflections, 64 variable parameters for Sr{sub 7}Ge{sub 6} and a=8.0853(6) A, b=24.545(2) A, c=8.9782(8) A, wR{sub 2}=0.085 (all data), 2307 independent reflections, 64 variable parameters for Ba{sub 7}Ge{sub 6}). Ba{sub 3}Sn{sub 2} crystallizes in an own structure type with the space group P4{sub 3}2{sub 1}2, Z=4, a=6.6854(2) A, c=17.842(2) A, wR{sub 2}=0.037 (all data), 1163 independent reflections, 25 variable parameters. In Sr{sub 7}Ge{sub 6} and Ba{sub 7}Ge{sub 6} the Ge atoms are arranged as Ge{sub 2} dumbbells and Ge{sub 4} four-membered atom chains. Their crystal structures cannot be rationalized according to the (8-N) rule. In contrast, Ba{sub 3}Sn{sub 2} presents Sn{sub 2} dumbbells as a main structural motif and thereby can be described as an electron precise Zintl phase. The chemical bonding situation in these structures is discussed on the basis of partial and total Density Of States (DOS) curves, band structures including fatbands, topological analysis of the Electron Localization Function (ELF) as well as Bader analysis of the bond critical points using the programs TB-LMTO-ASA and WIEN2K. While Ba{sub 3}Sn{sub 2} reveals semiconducting behaviour, all germanides Ae{sub 7}Ge{sub 6} (Ae=Ca, Sr, and Ba) show metallic properties and a considerable {pi}-bonding character between the Ge atoms of the four-membered chains and the dumbbells. The {pi}-bonding character of the germanides is best reflected by the resonance hybrid structures {l_brace}[Ge-Ge]{sup 6-}/[Ge-{sup ....}Ge-{sup ....}Ge-{sup ....}Ge]{sup 8-}{r_brace}{r_reversible}{l_brace}[Ge=Ge]{sup 4-}/[Ge-Ge-Ge-Ge]{sup 10-}{r_brace}. - Graphical abstract: The structure of Ba{sub 3}Sn{sub 2} contains Sn{sub 2} dumbbells as a main structural motif and thereby can be described as an electron precise Zintl phase. Ge{sub 2} dumbbells and Ge{sub 4} four-membered atom chains are the predominant features in Sr{sub 7}Ge{sub 6} and Ba{sub 7}Ge{sub 6}. Their crystal structures cannot be rationalized according to the (8-N) rule. While Ba{sub 3}Sn{sub 2} reveals semiconducting behaviour, the germanides Ae{sub 7}Ge{sub 6} (Ae=Ca, Sr, and Ba) show metallic properties and a considerable {pi}-bonding character between the Ge atoms of the four-membered chains and the dumbbells. Highlights: Black-Right-Pointing-Pointer The germanides Sr{sub 7}Ge{sub 6} and Ba{sub 7}Ge{sub 6} as well as the stannide Ba{sub 3}Sn{sub 2} have been synthesized. Black-Right-Pointing-Pointer In Sr{sub 7}Ge{sub 6} and Ba{sub 7}Ge{sub 6} the Ge atoms are arranged as dumbbells and four-membered atom chains. Black-Right-Pointing-Pointer Ba{sub 3}Sn{sub 2} presents Sn{sub 2} dumbbells as a main structural motif. Black-Right-Pointing-Pointer The chemical bonding situation within these structures is discussed.

  14. Wave-function engineering and absorption spectra in Si{sub 0.16}Ge{sub 0.84}/Ge{sub 0.94}Sn{sub 0.06}/Si{sub 0.16}Ge{sub 0.84} strained on relaxed Si{sub 0.10}Ge{sub 0.90} type I quantum well

    SciTech Connect (OSTI)

    Yahyaoui, N., E-mail: naima.yahyaoui@yahoo.fr, E-mail: moncef-said@yahoo.fr; Sfina, N.; Said, M., E-mail: naima.yahyaoui@yahoo.fr, E-mail: moncef-said@yahoo.fr [Laboratoire de la Matière Condensée et des Nanosciences (LMCN), Département de Physique, Faculté des Sciences de Monastir, Avenue de l'Environnement, 5019 Monastir (Tunisia); Lazzari, J.-L. [Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), UMR CNRS 7325, Aix-Marseille Université, Case 913, Campus de Luminy, 13288 Marseille cedex 9 (France); Bournel, A. [Institut d'Electronique Fondamentale (IEF), UMR CNRS 8622, Université Paris-Sud, Bât. 220, 91405 Orsay cedex (France)

    2014-01-21T23:59:59.000Z

    We theoretically investigate germanium-tin alloy as a semiconductor for the design of near infrared optical modulators in which the Ge{sub 1?x}Sn{sub x} alloy is the active region. We have calculated the electronic band parameters for heterointerfaces between strained Ge{sub 1?x}Sn{sub x} and relaxed Si{sub 1?y}Ge{sub y}. Then, a type-I strain-compensated Si{sub 0.10}Ge{sub 0.90}/Si{sub 0.16}Ge{sub 0.84}/Ge{sub 0.94}Sn{sub 0.06} quantum well heterostructure optimized in terms of compositions and thicknesses is studied by solving Schrödinger equation without and under applied bias voltage. The strong absorption coefficient (>1.5?×?10{sup 4}?cm{sup ?1}) and the shift of the direct transition under large Stark effect at 3?V are useful characteristics for the design of optoelectronic devices based on compressively strained IV-IV heterostructures at near infrared wavelengths.

  15. Indirect-to-direct band gap transition in relaxed and strained Ge{sub 1?x?y}Si{sub x}Sn{sub y} ternary alloys

    SciTech Connect (OSTI)

    Attiaoui, Anis; Moutanabbir, Oussama [Department of Engineering Physics, École Polytechnique de Montréal, Montréal, C.P. 6079, Succ. Centre-Ville, Montréal, Québec H3C 3A7 (Canada)

    2014-08-14T23:59:59.000Z

    Sn-containing group IV semiconductors create the possibility to independently control strain and band gap thus providing a wealth of opportunities to develop an entirely new class of low dimensional systems, heterostructures, and silicon-compatible electronic and optoelectronic devices. With this perspective, this work presents a detailed investigation of the band structure of strained and relaxed Ge{sub 1?x?y}Si{sub x}Sn{sub y} ternary alloys using a semi-empirical second nearest neighbors tight binding method. This method is based on an accurate evaluation of the deformation potential constants of Ge, Si, and ?-Sn using a stochastic Monte-Carlo approach as well as a gradient based optimization method. Moreover, a new and efficient differential evolution approach is also developed to accurately reproduce the experimental effective masses and band gaps. Based on this, we elucidated the influence of lattice disorder, strain, and composition on Ge{sub 1?x?y}Si{sub x}Sn{sub y} band gap energy and directness. For 0???x???0.4 and 0???y???0.2, we found that tensile strain lowers the critical content of Sn needed to achieve a direct band gap semiconductor with the corresponding band gap energies below 0.76?eV. This upper limit decreases to 0.43?eV for direct gap, fully relaxed ternary alloys. The obtained transition to direct band gap is given by y?>?0.605?×?x?+?0.077 and y?>?1.364?×?x?+?0.107 for epitaxially strained and fully relaxed alloys, respectively. The effects of strain, at a fixed composition, on band gap directness were also investigated and discussed.

  16. Tunable electronic properties and low thermal conductivity in synthetic colusites Cu{sub 26?x}Zn{sub x}V{sub 2}M{sub 6}S{sub 32} (x ? 4, M = Ge, Sn)

    SciTech Connect (OSTI)

    Suekuni, K., E-mail: ksuekuni@jaist.ac.jp; Kim, F. S. [Department of Quantum Matter, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8530 (Japan); Takabatake, T. [Department of Quantum Matter, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8530 (Japan); Institute for Advanced Materials Research, Hiroshima University, Higashi-Hiroshima 739-8530 (Japan)

    2014-08-14T23:59:59.000Z

    We have first synthesized Cu{sub 26?x}Zn{sub x}V{sub 2}M{sub 6}S{sub 32} (x???4, M?=?Ge, Sn) with the cubic colusite structure and measured the thermoelectric properties. For both M?=?Ge and Sn, the samples with x?=?0 show moderately large thermopower of +27 ?V/K at 300?K. The metallic conduction of p-type carriers and Pauli-paramagnetic behavior are consistent with the electron-deficient character expected from the formal charge Cu{sub 26}{sup 1+}V{sub 2}{sup 5+}M{sub 6}{sup 4+}S{sub 32}{sup 2?}. The substitution of Zn for Cu results in significant increases in both the electrical resistivity and thermopower. The resistivity of the samples with x?=?4 displays a three-dimensional variable-range hopping behavior at low temperatures. These facts indicate that the doped electrons fill the unoccupied states in the valence band and thereby the Fermi level moves to the localized electronic states at the top of the band. The lattice thermal conductivity is as low as ?1?W/Km at 300?K for all samples. The structural and thermoelectric properties of the colusites are discussed in comparison with those of doped tetrahedrite Cu{sub 12?x}Zn{sub x}Sb{sub 4}S{sub 13}.

  17. The effects of small metal additions ,,Co,Cu,Ga,Mn,Al,Bi,Sn... on the magnetocaloric properties of the Gd5Ge2Si2 alloy

    E-Print Network [OSTI]

    Kletetschka, Gunther

    .1 X=Fe,Cu,Co,Ga,Mn, or Al alloys are superior magnetic refrigerants compared to the undoped Gd5Ge2Si2 magnetic refrigerant because of its large "giant" magnetocaloric effect Sm between 270 and 300 K.1 more useful magnetic refrigerant than the undoped Gd5Ge2Si2 compound. Further, it was concluded

  18. SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6} - two new Ae-Zn-Sn polar intermetallic compounds (Ae: alkaline earth metal)

    SciTech Connect (OSTI)

    Stegmaier, Saskia [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstrasse 4, 85747 Garching (Germany); Faessler, Thomas F., E-mail: Thomas.Faessler@lrz.tum.de [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstrasse 4, 85747 Garching (Germany)

    2012-08-15T23:59:59.000Z

    SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}, two closely related new polar intermetallic compounds, were obtained by high temperature reactions of the elements. Their crystal structures were determined with single crystal XRD methods, and their electronic structures were analyzed by means of DFT calculations. The Zn-Sn structure part of SrZn{sub 2}Sn{sub 2} comprises (anti-)PbO-like {l_brace}ZnSn{sub 4/4}{r_brace} and {l_brace}SnZn{sub 4/4}{r_brace} layers. Ca{sub 2}Zn{sub 3}Sn{sub 6} shows similar {l_brace}ZnSn{sub 4/4}{r_brace} layers and {l_brace}Sn{sub 4}Zn{r_brace} slabs constructed of a covalently bonded Sn scaffold capped by Zn atoms. For both phases, the two types of layers are alternatingly stacked and interconnected via Zn-Sn bonds. SrZn{sub 2}Sn{sub 2} adopts the SrPd{sub 2}Bi{sub 2} structure type, and Ca{sub 2}Zn{sub 3}Sn{sub 6} is isotypic to the R{sub 2}Zn{sub 3}Ge{sub 6} compounds (R=La, Ce, Pr, Nd). Band structure calculations indicate that both SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6} are metallic. Analyses of the chemical bonding with the electron localization function (ELF) show lone pair like basins at Sn atoms and Zn-Sn bonding interactions between the layers for both title phases, and covalent Sn-Sn bonding within the {l_brace}Sn{sub 4}Zn{r_brace} layers of Ca{sub 2}Zn{sub 3}Sn{sub 6}. - Graphical abstract: Crystal structures of the new Ae-Zn-Sn polar intermetallic phases SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}. Highlights: Black-Right-Pointing-Pointer New polar intermetallic phases SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}. Black-Right-Pointing-Pointer Obtained by high temperature reactions of the elements. Black-Right-Pointing-Pointer Single crystal XRD structure determination and DFT electronic structure calculations. Black-Right-Pointing-Pointer Closely related crystal and electronic structures. Black-Right-Pointing-Pointer Metallic conductivity coexisting with lone pairs and covalent bonding features.

  19. HD1: Design and Fabrication of a 16 Tesla Nb3Sn Dipole Magnet

    E-Print Network [OSTI]

    Hafalia, A.R.

    2011-01-01T23:59:59.000Z

    and Fabrication of a 16 Tesla Nb 3 Sn Dipole Magnet A .R.ge nerating fields above 16 Tesla in practical acceleratordesign fields above 10 Tesla. In a series of magnet tests,

  20. Suppression of tin precipitation in SiSn alloy layers by implanted carbon

    SciTech Connect (OSTI)

    Gaiduk, P. I., E-mail: gaiduk@phys.au.dk [Department of Physics and Astronomy/iNANO, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C (Denmark); Belarusian State University, prosp. Nezavisimosti 4, 220030 Minsk (Belarus); Lundsgaard Hansen, J., E-mail: johnlh@phys.au.dk; Nylandsted Larsen, A., E-mail: anl@phys.au.dk [Department of Physics and Astronomy/iNANO, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C (Denmark); Bregolin, F. L., E-mail: f.lipp-bregolin@hzdr.de; Skorupa, W., E-mail: W.Skorupa@hzdr.de [Department of Semiconductor Materials, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany)

    2014-06-09T23:59:59.000Z

    By combining transmission electron microscopy and Rutherford backscattering spectrometry, we have identified carbon related suppression of dislocations and tin precipitation in supersaturated molecular-beam epitaxial grown SiSn alloy layers. Secondary ion mass spectrometry has exposed the accumulation of carbon in the SiSn layers after high temperature carbon implantation and high temperature thermal treatment. Strain-enhanced separation of point defects and formation of dopant-defect complexes are suggested to be responsible for the effects. The possibility for carbon assisted segregation-free high temperature growth of heteroepitaxial SiSn/Si and GeSn/Si structures is argued.

  1. Performance Boundaries in Nb3Sn Superconductors

    E-Print Network [OSTI]

    Godeke, Arno

    2006-01-01T23:59:59.000Z

    Boundaries in Nb 3 Sn Superconductors – Berkeley, CABoundaries in Nb 3 Sn Superconductors – Berkeley, CABoundaries in Nb 3 Sn Superconductors Arno Godeke Berkeley,

  2. Diffusion in SiGe and Ge

    E-Print Network [OSTI]

    Liao, Christopher Yuan Ting

    2010-01-01T23:59:59.000Z

    Claeys, et al. , "Si versus Ge for future microelectronics,"in Selectively Doped Si/Si x Ge 1-x Superlattices," PhysicalA. Fitzgerald, et al. , "Relaxed Ge x Si 1-x structures for

  3. Diffusion in SiGe and Ge

    E-Print Network [OSTI]

    Liao, Christopher Yuan Ting

    2010-01-01T23:59:59.000Z

    High-electron-mobility Si/SiGe heterostructures: influenceof the relaxed SiGe buffer layer," Semiconductor Science andFrom its discovery to SiGe devices," Materials Science in

  4. Thermal conductivity of bulk and nanowire Mg?SixSn1–x alloys from first principles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Wu; Lindsay, L.; Broido, D. A.; Stewart, Derek A.; Mingo, Natalio

    2012-11-01T23:59:59.000Z

    The lattice thermal conductivity (?) of the thermoelectric materials, Mg?Si, Mg?Sn, and their alloys, are calculated for bulk and nanowires, without adjustable parameters. We find good agreement with bulk experimental results. For large nanowire diameters, size effects are stronger for the alloy than for the pure compounds. For example, in 200 nm diameter nanowires ? is lower than its bulk value by 30%, 20%, and 20% for Mg?Si?.?Sn?.?, Mg?Si, and Mg?Sn, respectively. For nanowires less than 20 nm thick, the relative decrease surpasses 50%, and it becomes larger in the pure compounds than in the alloy. At room temperature, ? of Mg?SixSn1–x is less sensitive to nanostructuring size effects than SixGe1–x, but more sensitive than PbTexSe1–x. This suggests that further improvement of Mg?SixSn1–x as a nontoxic thermoelectric may be possible.

  5. Thermal conductivity of bulk and nanowire Mg?SixSn1–x alloys from first principles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Wu; Lindsay, L.; Broido, D. A.; Stewart, Derek A.; Mingo, Natalio

    2012-11-01T23:59:59.000Z

    The lattice thermal conductivity (?) of the thermoelectric materials, Mg?Si, Mg?Sn, and their alloys, are calculated for bulk and nanowires, without adjustable parameters. We find good agreement with bulk experimental results. For large nanowire diameters, size effects are stronger for the alloy than for the pure compounds. For example, in 200 nm diameter nanowires ? is lower than its bulk value by 30%, 20%, and 20% for Mg?Si?.?Sn?.?, Mg?Si, and Mg?Sn, respectively. For nanowires less than 20 nm thick, the relative decrease surpasses 50%, and it becomes larger in the pure compounds than in the alloy. At room temperature, ?more »of Mg?SixSn1–x is less sensitive to nanostructuring size effects than SixGe1–x, but more sensitive than PbTexSe1–x. This suggests that further improvement of Mg?SixSn1–x as a nontoxic thermoelectric may be possible.« less

  6. Structural and Magnetic properties of Gd 5 Si x Sn 4 x H.B. Wang, Z. Altounian and D.H. Ryan

    E-Print Network [OSTI]

    Ryan, Dominic

    ;ect in Gd 5 Si 2 Ge 2 3 suggesting po- tential applications in magnetic refrigeration. The strucStructural and Magnetic properties of Gd 5 Si x Sn 4 x H.B. Wang, Z. Altounian and D.H. Ryan. Structural and magnetic phase diagrams have been derived. Si-rich and Sn-rich alloys are orthorhombic

  7. The low-temperature form of calcium gold stannide, CaAuSn

    SciTech Connect (OSTI)

    Lin, Qisheng; Corbett, John D.

    2014-07-19T23:59:59.000Z

    The EuAuGe-type CaAuSn phase has been synthesized and single-crystal X-ray diffraction analysis reveals that it has an ortho­rhom­bic symmetry (space group Imm2), with a = 4.5261 (7) Å, b = 7.1356 (11) Å and c = 7.8147 (11) Å. The structure features puckered layers that are connected by homoatomic Au-Au and Sn-Sn inter­layer bonds. This structure is one of the two parent structures of its high-temperature polymorph (ca 873 K), which is an inter­growth structure of the EuAuGe- and SrMgSi-type structures in a 2:3 ratio.

  8. CHEM 114 GE 124 MATH 110 GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    2006-07 CHEM 114 GE 124 MATH 110 GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 GE 210 MATH 223CE 212 CMPT 116 Hum/SocSci Jr. GEOE 218 CE 225 MATH 224GE 213# GE 348# CE 295 English 11x# CE 315 CE 311 CE 318 CE 319 CE 317 CE 316CE 327 CE 321 Sr Sci elect#CE 329 CE 328 GE 300# Eng/Sr Sci Elec# CE Elec

  9. CHEM 114 GE 124 MATH 110 COMM 102GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    CHEM 114 GE 124 MATH 110 COMM 102GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 CMPT 116CHEM 250# MATH 223 EE 201 GE 213 Grp. A elective*CHE 223 Hum/SocSci Jr. MATH 224 English 11x CHE 220CHE 210 CHECHE 413 Grp. B elective#* Grp. B elective*#CHE 424 CHE 421 CHE 422 GE 348# CHE 423 GE 449# CH E 470

  10. CHEM 114 GE 124 MATH 110 COMM 102GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    CHEM 114 GE 124 MATH 110 COMM 102GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 CMPT 116CHEM 250# MATH 223 EE 201 GE 213 Grp. A elective*CHE 223 HSS@# MATH 224 English 11x CHE 220CHE 210 CHE 323 CHE Grp. B elective#* Grp. B elective*#CHE 424 CHE 421 CHE 422 GE 348# CHE 423 GE 449# CH E 470^ Chemical

  11. CHEM 114 GE 124 MATH 110 GE 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    CHEM 114 GE 124 MATH 110 GE 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 ME 227 GE 213# MATH 223 EE 201ME 214 CMPT 116 ME 215 GE 226 MATH 224 Hum/SocSci@# ME 251 ME 229 ME 318 ME 335 ME 313 ME 316 ME 352ME 330 GE 348# ME 328 ME 327 ME 323 ME 321ME 324 RCM 300# ME 418 ME 417 ME 450 ME 431

  12. GE ?????????????????4G?????...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GE 4G Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click...

  13. GE Healthcare Introduction

    E-Print Network [OSTI]

    Lebendiker, Mario

    GE Healthcare Introduction HR 16 columns are designed for high resolution liquid chromatography your local GE Healthcare office. System compatibility HR 16 columns are designed to be used with ÄKTATM. Wash the parts thoroughly in distilled water. 4. Reassemble the column (see Assembling the column above

  14. Structural distortion in RPt sub 2 Sn sub 2 compounds (R = rare earth)

    SciTech Connect (OSTI)

    Latroche, M.; Selsane, M.; Godart, C.; Schiffmacher, G. (Centre National de la Recherche Scientifique (CNRS), 92 - Meudon-Bellevue (France)); Beyerman, W.P.; Thompson, J.D. (Los Alamos National Lab., NM (USA))

    1991-01-01T23:59:59.000Z

    CeM{sub 2}X{sub 2} compounds (M-transition metals, X = Si, Ge, Sn) exhibit very exotic properties such as intermediate valence state, heavy fermion, magnetism, and superconductivity. Most of them crystallize in the ThCr{sub 2}Si{sub 2} type structure (14/nmm) while a few adopt the CeBe{sub 2}Ge{sub 2} primitive one (P4/nmmm). Among these compounds, CePt{sub 2}Sn{sub 2} has the heaviest known specific heat coefficient ({gamma} = 3.5 J/mol-K{sup 2}) and orders antiferromagnetically at T{sub N} = 0.88 K. Samples of CePt{sub 2}Sn{sub 2}, Ce{sub 0.e}La{sub 0.2}Pt{sub 2}Sn{sub 2}, and LaPt{sub 2}Sn{sub 2} have been studied by X-ray powder diffraction experiments including Rietveld calculations before and after annealing. As-cast samples can be indexed in the tetragonal primitive cell; however, re- examination of annealed samples (1 3 days at 800{degrees}C and 3 weeks at 700{degrees}C) reveals a monoclinic distortion of the lattice. Such a distortion has already been observed for CeNi{sub 2}Sn{sub 2}. Furthermore, our diffraction patterns show evidence for superlattice lines at twice the unit cell parameters, which was verified by transmission electron microscopy. Microprobes analysis on these samples show that the Pt sublattice is slightly substoichiometric (97.5%). Thus strains due to large atomic radii and ordering of Pt vacancies could be responsible for the monoclinic distortion and superlattice lines. 13 refs., 3 figs., 1 tab.

  15. arXiv:cond-mat/0610736v126Oct2006 Pure spin currents induced by spin-dependent scattering processes in SiGe quantum

    E-Print Network [OSTI]

    Ganichev, Sergey

    in SiGe quantum well structures S.D. Ganichev1 , S.N. Danilov1 , V.V. Bel'kov1,2 , S. Giglberger1 , S experiments on SiGe heterostructures the pure spin current is converted into an electric current applying been carried out on III-V compounds, some recent results obtained on non-magnetic SiGe nanostructures

  16. Chevron, GE form Technology Alliance

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    form Technology Alliance February 3, 2014 HOUSTON, TX, Feb. 3, 2014-Chevron Energy Technology Company and GE Oil & Gas announced today the creation of the Chevron GE Technology...

  17. Research into the microstructure and mechanical behavior of eutectic Bi-Sn and In-Sn

    SciTech Connect (OSTI)

    Goldstein, J.L.F.; Mei, Z.; Morris, J.W. Jr. [Lawrence Berkeley Lab., CA (United States)]|[California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

    1993-08-01T23:59:59.000Z

    This manuscript reports on research into two low-melting, lead-free solder alloys, eutectic Bi-Sn and eutectic In-Sn. The microstructures were found to depend on both cooling rate and substrate, with the greatest variability in the In-Sn alloy. The nature of the intermetallic layer formed at the solder-substrate interface depends on both the solder and the substrate (Cu versus Ni). Also, the microstructure of the Bi-Sn can recrystallize during deformation, which is not the case with In-Sn. Data from creep and constant strain rate tests are given for slowly cooled samples. The creep behavior of In-Sn is constant with temperature, but the creep seems to be controlled by the In-rich phase in In-Sn on Cu and by the Sn-rich phase in In-Sn on Ni. Bi-Sn exhibits different creep behavior at temperatures above 40 {degrees}C than at 20 {degrees}C or lower. Stress-strain curves of Bi-Sn on Cu and In-Sn on Cu are similar, while In-Sn on Ni behaves differently. This is explained in terms of the deformation patterns in the alloys.

  18. GE Global Research Locations | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy,ARMFormsGasReleaseSpeechesHall ATours,Dioxide and MethaneLocations GE

  19. GE Global Research Leadership | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) Environmental AssessmentsGeoffrey Campbell is theOpportunitiesTheGAOHome >About GE

  20. GE Researcher Discusses Leadership | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist.Newof EnergyFunding OpportunityF G F ! ( ! ( ! ( !ProgressGE

  1. Effect of mixed Ge/Si cross-linking on the physical properties of amorphous Ge-Si-Te networks

    SciTech Connect (OSTI)

    Gunasekera, K.; Boolchand, P. [School of Electronics and Computing Systems, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, Ohio 45221-0030 (United States); Micoulaut, M., E-mail: mmi@lptl.jussieu.fr [Laboratoire de Physique Théorique de la Matière Condensée, Université Pierre et Marie Curie, 4 Place Jussieu, F-75252 Paris Cedex 05 (France)

    2014-04-28T23:59:59.000Z

    Amorphous Ge{sub x}Si{sub x}Te{sub 1?2x} glasses are studied as a function of composition by a combination of experimental and theoretical methods, allowing for a full description of the network structure in relationship with physico-chemical properties. Calorimetric and thermal measurements reveal that such glasses display an anomalous behavior across a range of compositions x{sub c1}=7.5% and Ge, Si) are increased. The structural manifestation of these anomalies is understood from ?{sup 119}Sn Mössbauer spectroscopy and First Principles Molecular Dynamics at selected compositions (Ge{sub 20}Te{sub 80}, Si{sub 20}Te{sub 80}, and Ge{sub 10}Si{sub 10}Te{sub 80}). The numerical models reveal the quite different roles played by the modifier or network cross-linker Ge or Si atoms, Si being more tetrahedral in sp{sup 3} geometry, whereas Mössbauer spectroscopy shows that the nature of chemical bonding is dramatically changed around x??8%. The precise evolution of the local structure and chemical bonding ultimately allows understanding the origin of the intermediate phase in these complex tellurides.

  2. Anomalous temperature behavior of Sn impurities

    SciTech Connect (OSTI)

    Haskel, D.; Shechter, H. (Department of Physics, Technion, Haifa (Israel)); Stern, E.A.; Newville, M. (Department of Physics FM-15, University of Washington, Seattle, Washington 98195 (United States)); Yacoby, Y. (Racah Institute of Physics, Hebrew University, Jerusalem (Israel))

    1993-06-01T23:59:59.000Z

    Sn impurities in Pb and Ag hosts have been investigated by Moessbauer effect and in Pb by x-ray-absorption fine-structure (XAFS) studies. The Sn atoms are dissolved up to at least 2 at. % in Pb and up to at least 8 at. % in Ag for the temperature ranges investigated. The concentration limit for Sn-Sn interactions is 1 at. % for Pb and 2 at. % for Ag as determined experimentally by lowering the Sn concentration until no appreciable change occurs in the Moessbauer effect. XAFS measurements verify that the Sn impurities in Pb are dissolved and predominantly at substitutional sites. For both hosts the temperature dependence of the spectral intensities of isolated Sn impurities below a temperature [ital T][sub 0] is as expected for vibrating about a lattice site. Above [ital T][sub 0] the Moessbauer spectral intensity exhibits a greatly increased rate of drop-off with temperature without appreciable broadening. This drop-off is too steep to be explained by ordinary anharmonic effects and can be explained by a liquidlike rapid hopping of the Sn, localized about a lattice site. Higher-entropy-density regions of radii somewhat more than an atomic spacing surround such impurities, and can act as nucleation sites for three-dimensional melting.

  3. Local order measurement in SnGe alloys and monolayer Sn films on Si with reflection electron energy loss spectrometry

    E-Print Network [OSTI]

    Atwater, Harry

    fine structure EXELFS data obtained by reflection electron energy loss spectrometry REELS-range order obtained using reflection high energy electron diffraction. The results suggest that EXELFS synthesis of artificial structures with abrupt strain and composition profiles. Re- flection high energy

  4. Thermoelectric properties of nanoporous Ge

    E-Print Network [OSTI]

    Lee, Joo-Hyoung

    We computed thermoelectric properties of nanoporous Ge (np-Ge) with aligned pores along the [001] direction through a combined classical molecular dynamics and first-principles electronic structure approach. A significant ...

  5. GE Anna Heijbel / The Storm

    E-Print Network [OSTI]

    Tian, Weidong

    1 / GE Anna Heijbel / The Storm® Confocal Optics 50, 100, 200 µm 5 IQTL · ·DNA ·DNA Gels, blots, tissue sections (not in situ), radio-TLC & X-Ray diffraction #12;2 / GE Anna Heijbel / Phosphor µm 1010 43 x 35 cm43 x 35 cm Scanning Technology #12;3 / GE Anna Heijbel / Confocal Optics PMTPMT

  6. HSE 1 HSE 2 HSE 3 GE 1 GE 2 GE 3 Residual effects of Large Vessels in GE BOLD Differential Mapping of Ocular Dominance Columns

    E-Print Network [OSTI]

    HSE 1 HSE 2 HSE 3 GE 1 GE 2 GE 3 Residual effects of Large Vessels in GE BOLD Differential Mapping these techniques in humans. Previous human studies (4-6) instead used the conventional GE BOLD technique, combined and limitations of GE BOLD differential mapping as compared to HSE BOLD differential mapping of ocular dominance

  7. Recoil Studies in the Reaction of 12-C Ions with the Enriched Isotope 118-Sn

    E-Print Network [OSTI]

    A. R. Balabekyan; A. S. Danagulyan; J. R. Drnoyan; N. A. Demekhina; G. H. Hovhannisyan; J. Adam; V. G. Kalinnikov; M. I. Krivopustov; V. S. Pronskikh; V. I. Stegailov; A. A. Solnyshkin; V. M. Tsoupko-Sitnikov; S. G. Mashnik; K. K. Gudima

    2009-05-04T23:59:59.000Z

    The recoil properties of the product nuclei from the interaction of 2.2 GeV/nucleon 12-C ions from Nuclotron of the Laboratory of High Energies (LHE), Joint Institute for Nuclear Research (JINR) at Dubna with a 118-Sn target have been studied using catcher foils. The experimental data were analyzed using the mathematical formalism of the standard two-step vector model. The results for 12-C ions are compared with those for deuterons and protons. Three different Los Alamos versions of the Quark-Gluon String Model (LAQGSM) were used for comparison with our experimental data.

  8. CTu2J.4.pdf CLEO Technical Digest OSA 2012 Selective-Area Growth of Ge and Ge/SiGe Quantum Wells

    E-Print Network [OSTI]

    Miller, David A. B.

    CTu2J.4.pdf CLEO Technical Digest © OSA 2012 Selective-Area Growth of Ge and Ge/SiGe Quantum Wells process for growing high-quality bulk Ge and Ge/SiGe quantum wells in selected areas of 3 µm thick silicon. Introduction and motivation Ge and especially Ge/SiGe quantum wells exhibit strong electroabsorption (Franz

  9. GE Wins Manufacturing Leadership Award |GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    secured software platform that delivers data and visualizations to all major artificial lift functions at GE Oil & Gas. Several analytic modules were built to extract meaningful...

  10. GE Partners on Microgrid Project | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Academia Partner on Microgrid Project GE Awarded a 1.2M Department of Energy Grant to Design Technology to Keep Electricity Flowing after Catastrophic Weather Events...

  11. GE, Aavid Commercialize Dual Cool Jets Technology | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    market. GE's broad array of industrial businesses requires highly advanced and reliable electronics that are increasingly driving the need for advanced cooling solutions to...

  12. GE, University of Washington Disease Detection | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    excited about this team's unique ability to combine new designs for paper-based microfluidics with new nucleic amplification methods and GE's novel paper chemistries to help...

  13. The GE Store

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructureProposedPAGESafetyTed5,AuditThe FiveBiofuelsGE Store for

  14. GE Healthcare Product Guide 2007

    E-Print Network [OSTI]

    Lebendiker, Mario

    GE Healthcare BioProcess Product Guide 2007 #12;How to contact us Europe www.gehealthcare.com/bioprocess or by phone (T), fax (F), and Email Austria T: +43 1 57 606 1613 F: +43 1 57 606 1614 Email: cust.orderde@ge.com Belgium T: 0800 73890 F: 02 416 8206 Email: order.bnl@ge.com Central and East Europe (Austria) T: +43 1

  15. Magnetic Refrigeration | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    temperature," said Frank Johnson, a materials scientist and project leader on GE's magnetic refrigeration project. Developed over the past decade, these new magnetocaloric...

  16. Serial and parallel Si, Ge, and SiGe direct-write with scanning...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Serial and parallel Si, Ge, and SiGe direct-write with scanning probes and conducting stamps. Serial and parallel Si, Ge, and SiGe direct-write with scanning probes and conducting...

  17. Development of high-temperature ferromagnetism in SnO2 and paramagneti...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    high-temperature ferromagnetism in SnO2 and paramagnetism in SnO by Fe doping. Development of high-temperature ferromagnetism in SnO2 and paramagnetism in SnO by Fe doping....

  18. Development of High-Temperature Ferromagnetism in SnO and Paramagnetis...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    High-Temperature Ferromagnetism in SnO and Paramagnetism in SnO by Fe Doping. Development of High-Temperature Ferromagnetism in SnO and Paramagnetism in SnO by Fe Doping. Abstract:...

  19. CHEM 114 GE 124 MATH 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    2006-07 CHEM 114 GE 124 MATH 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 GEOL 245 MATH 223 CE 328 CE 212 CE 225 CE 295GE 213# MATH 224 GEOL 224 GEOE 218 GEOL 258 Hum/SocSci Jr. GEOE 315 GEOE 475 Grp C Elec.# GE 348#CE 318 CE 319 ENG 11X# GEOL 463 or Grp B Elec.# GEOL 226 GE 300# CE 316

  20. CHEM 114 GE 124 MATH 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    2005-2006 CHEM 114 GE 124 MATH 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 GEOL 245 MATH 223 CE 328 CE 212 CE 225 CE 295GE 213# MATH 224 GEOL 224 GEOE 218 GEOL 258 BusSci/HSS# GEOE 315 GEOE 475 Grp C Elec.# GE 348#CE 318 CE 319 ENG 11X# GEOL 463 or Grp B Elec.# GEOL 226 GE 300# CE 316 Grp

  1. Electronic Structure, Oxidation State of Sn, and Chemical Stability of Photovoltaic Perovskite Variant Cs2SnI6

    E-Print Network [OSTI]

    Xiao, Zewen; Zhang, Xiao; Zhou, Yuanyuan; Hosono, Hideo; Kamiya, Toshio

    2015-01-01T23:59:59.000Z

    Cs2SnI6, a variant of perovskite CsSnI3, is expected for a photovoltaic material. Based on a simple ionic model, it is expected that Cs2SnI6 is composed of Cs+, I-, and Sn4+ ions and that the band gap is primarily made of occupied I- 5p6 valence band maximum (VBM) and unoccupied Sn4+ 5s conduction band minimum (CBM) similar to SnO2. In this work, we performed density functional theory (DFT) calculations and revealed that the real charge state of the Sn ion in this compound is +2 similar to CsSnI3. This is due to strong covalent nature between the I ion and the Sn ion, the VBM consists of I 5p - I 5p antibonding states, and the CBM of I 5p - Sn 5s antibonding states. The +2 oxidation state of Sn is realized by the apparent charge state of I-2/3, because the I 5p - Sn 5s antibonding states form the unoccupied CBM and apparently 1/18 of the I 5p orbitals are unoccupied. These results are further supported by comparing chemical bonding analyses with those of related compounds. The chemical stability of the Cs2SnI...

  2. Low-voltage broad-band electroabsorption from thin Ge/SiGe

    E-Print Network [OSTI]

    Miller, David A. B.

    Low-voltage broad-band electroabsorption from thin Ge/SiGe quantum wells epitaxially grown than 5 dB over the entire telecommunication S- and C-bands with only 1V drive using a new Ge/SiGe QW epitaxy design approach; further, this is demonstrated with the thinnest Ge/SiGe epitaxy to date, using

  3. Strained Si, SiGe, and Ge on-insulator: review of wafer bonding fabrication techniques

    E-Print Network [OSTI]

    Strained Si, SiGe, and Ge on-insulator: review of wafer bonding fabrication techniques Gianni was arranged by Prof. C.K. Maiti Abstract Techniques for fabricating strained Si, SiGe, and Ge on is presented, with a detailed discussion of wafer bonding approaches for strained Si, SiGe, and Ge on

  4. The Exceptionally Luminous Type II-L SN 2008es

    E-Print Network [OSTI]

    A. A. Miller; R. Chornock; D. A. Perley; M. Ganeshalingam; W. Li; N. R. Butler; J. S. Bloom; N. Smith; M. Modjaz; D. Poznanski; A. V. Filippenko; C. V. Griffith; J. H. Shiode; J. M. Silverman

    2008-09-03T23:59:59.000Z

    We report on our early photometric and spectroscopic observations of the extremely luminous Type II supernova (SN) 2008es. With an observed peak optical magnitude of m_V = 17.8 and at a redshift z = 0.213, SN 2008es had a peak absolute magnitude of M_V = -22.3, making it the second most luminous SN ever observed. The photometric evolution of SN 2008es exhibits a fast decline rate (~0.042 mag d^-1), similar to the extremely luminous Type II-L SN 2005ap. We show that SN 2008es spectroscopically resembles the luminous Type II-L SN 1979C. Although the spectra of SN 2008es lack the narrow and intermediate-width line emission typically associated with the interaction of a SN with the circumstellar medium of its progenitor star, we argue that the extreme luminosity of SN 2008es is powered via strong interaction with a dense, optically thick circumstellar medium. The integrated bolometric luminosity of SN 2008es yields a total radiated energy at ultraviolet and optical wavelengths of >10^51 ergs. Finally, we examine the apparently anomalous rate at which the Texas Supernova Search has discovered rare kinds of supernovae, including the five most luminous supernovae observed to date, and find that their results are consistent with those of other modern SN searches.

  5. Materials Data on Li2SnGe (SG:216) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. High energy octupole resonance in Sn-116

    E-Print Network [OSTI]

    Clark, HL; Youngblood, David H.; Lui, YW.

    1996-01-01T23:59:59.000Z

    The region of excitation energy from 7 less than or equal to E(x) less than or equal to 38 MeV in Sn-116 was studied with inelastic scattering of 240 MeV alpha particles. Parameters obtained for the isoscalar giant monopole resonance...

  7. GE, Berkeley Energy Storage for Electric Vehicles | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Just Add Water: GE, Berkeley Lab Explore Possible Key to Energy Storage for Electric Vehicles Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new...

  8. Cold Spray and GE Technology | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    difference of the work done at GE Global Research is the development of cold spray for additive manufacturing, where we adapt this novel coating process to build 3D shapes....

  9. GE Researcher Explores Science Behind Movie Chappie | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    When Will We Have Robot Best Friends? A GE Researcher Explores the Science Behind Movie Magic Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new...

  10. Joining GE Global Research Thermal Systems | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Alps. With more than 16 years working as an aerospace engineer in the development of gas turbine jet engines, I had GE on my radar screen right from the beginning when I was...

  11. Uniaxially stressed Ge:Ga and Ge:Be

    SciTech Connect (OSTI)

    Dubon, O.D. Jr.

    1992-12-01T23:59:59.000Z

    The application of a large uniaxial stress to p-type Ge single crystals changes the character of both the valence band and the energy levels associated with the acceptors. Changes include the splitting of the fourfold degeneracy of the valence band top and the reduction of the ionization energy of shallow acceptors. In order to study the effect of uniaxial stress on transport properties of photoexcited holes, a variable temperature photo-Hall effect system was built in which stressed Ge:Ga and Ge:Be could be characterized. Results indicate that stress increases the lifetime and Hall mobility of photoexcited holes. These observations may help further the understanding of fundamental physical processes that affect the performance of stressed Ge photoconductors including the capture of holes by shallow acceptors.

  12. Ternary lithium stannides Li{sub x}T{sub 3}Sn{sub 7-x} (T=Rh, Ir)

    SciTech Connect (OSTI)

    Sreeraj, Puravankara [Institut fuer Anorganische und Analytische Chemie, NRW Graduate School of Chemistry, and Sonderforschungsbereich 458, Universitaet Muenster, Corrensstrasse 30, 48149 Muenster (Germany); Kurowski, Daniel [Institut fuer Anorganische und Analytische Chemie, NRW Graduate School of Chemistry, and Sonderforschungsbereich 458, Universitaet Muenster, Corrensstrasse 30, 48149 Muenster (Germany); Hoffmann, Rolf-Dieter [Institut fuer Anorganische und Analytische Chemie, NRW Graduate School of Chemistry, and Sonderforschungsbereich 458, Universitaet Muenster, Corrensstrasse 30, 48149 Muenster (Germany); Wu Zhiyun [Institut fuer Anorganische und Analytische Chemie, NRW Graduate School of Chemistry, and Sonderforschungsbereich 458, Universitaet Muenster, Corrensstrasse 30, 48149 Muenster (Germany); Poettgen, Rainer [Institut fuer Anorganische und Analytische Chemie, NRW Graduate School of Chemistry, and Sonderforschungsbereich 458, Universitaet Muenster, Corrensstrasse 30, 48149 Muenster (Germany)]. E-mail: pottgen@uni-muenster.de

    2005-11-15T23:59:59.000Z

    The ternary stannides Li{sub x}Rh{sub 3}Sn{sub 7-x} (x=0.45, 0.64, 0.80) and Li{sub x}Ir{sub 3}Sn{sub 7-x} (x=0.62 and 0.66) were synthesized from the elements in sealed tantalum tubes in a water-cooled sample chamber of an induction furnace. The samples were characterized by X-ray diffraction on powders and single crystals. The stannides adopt the cubic Ir{sub 3}Ge{sub 7}-type structure (space group Im3-bar m, Z=4). In this structure type the tin atoms occupy the Wyckoff positions 12d and 16f and form two interpenetrating frameworks consisting of cubes and square antiprisms. The rhodium and iridium atoms center the square antiprisms and are arranged in pairs. With increasing lithium substitution the lattice parameter of Ir{sub 3}Sn{sub 7} (936.7) decreases via 932.2pm (x=0.62) to 931.2pm (x=0.66), while the Ir-Ir distance remains almost the same (290pm). A similar trend is observed for the rhodium compounds. The lithium atoms substitute Sn on both framework sites. However, the 16f site shows a substantially larger preference for Li occupation. This is in contrast to the isotypic magnesium based compounds.

  13. SNEWS: A Neutrino Early Warning System for Galactic SN II

    E-Print Network [OSTI]

    Alec Habig; for the SNEWS Collaboration

    1999-12-14T23:59:59.000Z

    The detection of neutrinos from SN1987A confirmed the core-collapse nature of SN II, but the neutrinos were not noticed until after the optical discovery. The current generation of neutrino experiments are both much larger and actively looking for SN neutrinos in real time. Since neutrinos escape a new SN promptly while the first photons are not produced until the photospheric shock breakout hours later, these experiments can provide an early warning of a coming galactic SN II. A coincidence network between neutrino experiments has been established to minimize response time, eliminate experimental false alarms, and possibly provide some pointing to the impending event from neutrino wave-front timing.

  14. Fusion of radioactive $^{132}$Sn with $^{64}$Ni

    E-Print Network [OSTI]

    J. F. Liang; D. Shapira; J. R. Beene; C. J. Gross; R. L. Varner; A. Galindo-Uribarri; J. Gomez del Campo; P. A. Hausladen; P. E. Mueller; D. W. Stracener; H. Amro; J. J. Kolata; J. D. Bierman; A. L. Caraley; K. L. Jones; Y. Larochelle; W. Loveland; D. Peterson

    2007-04-05T23:59:59.000Z

    Evaporation residue and fission cross sections of radioactive $^{132}$Sn on $^{64}$Ni were measured near the Coulomb barrier. A large sub-barrier fusion enhancement was observed. Coupled-channel calculations including inelastic excitation of the projectile and target, and neutron transfer are in good agreement with the measured fusion excitation function. When the change in nuclear size and shift in barrier height are accounted for, there is no extra fusion enhancement in $^{132}$Sn+$^{64}$Ni with respect to stable Sn+$^{64}$Ni. A systematic comparison of evaporation residue cross sections for the fusion of even $^{112-124}$Sn and $^{132}$Sn with $^{64}$Ni is presented.

  15. Recommended GE Curriculum for the BSEE Majors

    E-Print Network [OSTI]

    Ravikumar, B.

    Recommended GE Curriculum for the BSEE Majors Area Subjects Suggested GE Courses Courses Actual units GE Units A. Communication and Critical Thinking (9) A.2. Fund. of Communication ENGL 101 4 4 A.3, Theatre, Dance and Music and Film Select from the GE C.1 list in the SSU Catalog 3 3 C.2. Literature

  16. LARP Long Nb3Sn Quadrupole Design.

    SciTech Connect (OSTI)

    Ambrosio,G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidize, G.; Dietderich, D.; Feher, S.; Felice, H.; Ferracin, P.; Ghosh, A.; Hafalia, A.R.; Hannaford, C.R.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Lietzke, A.; McInturff, A.; Muratore, J.; Nobrega, F.; Novitsky, I.; Sabbi, G.L.; Schmalzle, J.; Tartaglia, M.; Turrioni, D.; Wanderer, P.; Whitson, G.; Zlobin, A.V.

    2007-08-27T23:59:59.000Z

    A major milestone for the LHC Accelerator Research Program (LARP) is the test, by the end of 2009, of two 4m-long quadrupole magnets (LQ) wound with Nb{sub 3}Sn conductor. The goal of these magnets is to be a proof of principle that Nb{sub 3}Sn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based on the design of the LARP Technological Quadrupoles, presently under development at FNAL and LBNL, with 90-mm aperture and gradient higher than 200 T/m. The design of the first LQ model will be completed by the end of 2007 with the selection of a mechanical design. In this paper we present the coil design addressing some fabrication technology issues, the quench protection study, and three designs of the support structure.

  17. LARP Long Nb3Sn Quadrupole Design

    SciTech Connect (OSTI)

    Ambrosio, G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidize, G.; Dietderich, D.; Feher, S.; Ferracin, P.; Ghosh, A.; Hafalia, R.; Hannaford, R.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Lietzke, A.; McInturff, A.; Muratore, J.; Nobrega, F.; Novitsky, I.; Sabbi, G.L.; Schmalzle, J.; Tartaglia, M.; Turrioni, D.; Wanderer, P.; Whitson, G.; Zlobin, A.V.

    2008-06-01T23:59:59.000Z

    A major milestone for the LHC Accelerator Research Program (LARP) is the test, by the end of 2009, of two 4m-long quadrupole magnets (LQ) wound with Nb{sub 3}Sn conductor. The goal of these magnets is to be a proof of principle that Nb{sub 3}Sn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based on the design of the LARP Technological Quadrupoles, presently under development at FNAL and LBNL, with 90-mm aperture and gradient higher than 200 T/m. The design of the first LQ model will be completed by the end of 2007 with the selection of a mechanical design. In this paper we present the coil design addressing some fabrication technology issues, the quench protection study, and three designs of the support structure.

  18. GeSi intermixing in Ge quantum dots on Si,,001... and Si,,111... F. Boscherinia)

    E-Print Network [OSTI]

    Ge­Si intermixing in Ge quantum dots on Si,,001... and Si,,111... F. Boscherinia) Laboratori December 1999 Exploiting Ge K-edge x-ray absorption spectroscopy we provide direct evidence of Si­Ge intermixing in self-organized strained and unstrained Ge quantum dots on Si, and provide a quantitative

  19. Nonlithographic epitaxial SnxGe1x dense nanowire arrays grown on Ge,,001...

    E-Print Network [OSTI]

    Atwater, Harry

    Nonlithographic epitaxial SnxGe1Àx dense nanowire arrays grown on Ge,,001... Regina Ragan-thick SnxGe1 x /Ge(001) epitaxial films with 0 x 0.085 by molecular-beam epitaxy. These films evolve during growth into a dense array of SnxGe1 x nanowires oriented along 001 , as confirmed by composition contrast

  20. Properties of SN-host galaxies

    E-Print Network [OSTI]

    F. Combes

    2003-08-08T23:59:59.000Z

    It is of prime importance to recognize evolution and extinction effects in supernovae results as a function of redshift, for SN Ia to be considered as distance indicators. This review surveys all observational data searching for an evolution and/or extinction, according to host morphology. For instance, it has been observed that high-z SNe Ia have bluer colours than the local ones: although this goes against extinction to explain why SN are dimmer with redshift until z ~ 1, supporting a decelerating universe, it also demonstrates intrinsic evolution effects. -- SNe Ia could evolve because the age and metallicity of their progenitors evolve. The main parameter is carbon abundance. Smaller C leads to a dimmer SN Ia and also less scatter on peak brightness, as it is the case in elliptical galaxy today. Age of the progenitor is an important factor: young populations lead to brighter SNe Ia, as in spiral galaxies, and a spread in ages lead to a larger scatter, explaining the observed lower scatter at high z. -- Selection biases also play a role, like the Malmquist bias; high-z SNe Ia are found at larger distance from their host center: there is more obscuration in the center, and also detection is easier with no contamination from the center. This might be one of the reason why less obscuration has been found for SNe Ia at high z. -- There is clearly a sample evolution with z: currently only the less bright SNe Ia are detected at high z, with less scatter. The brightest objects have a slowly declining light-curve, and at high z, no slow decline has been observed. This may be interpreted as an age effect, high-z SN having younger progenitors.

  1. Giant-Resonances in Sn-112

    E-Print Network [OSTI]

    Lui, YW; Bogucki, P.; Bronson, J. D.; Youngblood, David H.; Garg, U.

    1984-01-01T23:59:59.000Z

    V EX=15.5 0.2 MeV T' =5.5+0.2 MeV FIG. 3. Behavior of giant resonance parameters in Sn iso- topes. 57% L=2 ? l6.2 /o L=O+ 49.0 /o L=2 100 E b lo 10 L=2+5.6% L=4 I I I 2 4 6 8 ec ~(deq ) 10 l2 14 FIG. 2. Angular distributions obtained...

  2. Pressure-induced transformations in amorphous Si-Ge alloy

    SciTech Connect (OSTI)

    Coppari, F.; Polian, A.; Menguy, N.; Trapananti, A.; Congeduti, A.; Newville, M.; Prakapenka, V.B.; Choi, Y.; Principi, E.; Di Cicco, A. (CNRS-UMR); (UC); (Camerino)

    2012-03-14T23:59:59.000Z

    The pressure behavior of an amorphous Si-rich SiGe alloy ({alpha}-Si{sub x}Ge{sub 1-x}, x = 0.75) has been investigated up to about 30 GPa, by a combination of Raman spectroscopy, x-ray absorption spectroscopy, and x-ray diffraction measurements. The trends of microscopic structural properties and of the Raman-active phonon modes are presented in the whole pressure range. Nucleation of nanocrystalline alloy particles and metallization have been observed above 12 GPa, with a range of about 2 GPa of coexistence of amorphous and crystalline phases. Transformations from the amorphous tetrahedral, to the crystalline tetragonal ({beta}-Sn) and to the simple hexagonal structures have been observed around 13.8 and 21.8 GPa. The recovered sample upon depressurization, below about 4 GPa, shows a local structure similar to the as-deposited one. Inhomogeneities of the amorphous texture at the nanometric scale, probed by high-resolution transmission electron microscopy, indicate that the recovered amorphous sample has a different ordering at this scale, and therefore the transformations can not be considered fully reversible. The role of disordered grain boundaries at high pressure and the possible presence of a high-density amorphous phase are discussed.

  3. Elastic alpha-scattering of 112Sn and 124Sn at astrophysically relevant energies

    E-Print Network [OSTI]

    D. Galaviz; Zs. Fulop; Gy. Gyurky; Z. Mate; P. Mohr; T. Rauscher; E. Somorjai; A. Zilges

    2005-05-27T23:59:59.000Z

    The cross sections for the elastic scattering reactions {112,124}Sn(a,a){112,124}Sn at energies above and below the Coulomb barrier are presented and compared to predictions for global alpha-nucleus potentials. The high precision of the new data allows a study of the global alpha-nucleus potentials at both the proton and neutron-rich sides of an isotopic chain. In addition, local alpha-nucleus potentials have been extracted for both nuclei, and used to reproduce elastic scattering data at higher energies. Predictions from the capture cross section of the reaction 112Sn(a,g)116Te at astrophysically relevant energies are presented and compared to experimental data.

  4. Giant resonances in Sn-112 and Sn-124: Isotopic dependence of monopole resonance energies

    E-Print Network [OSTI]

    Lui, YW; Youngblood, David H.; Tokimoto, Y.; Clark, HL; John, B.

    2004-01-01T23:59:59.000Z

    Giant resonances in 112Sn and 124Sn: Isotopic dependence of monopole resonance energies Y.-W. Lui, D. H. Youngblood, Y. Tokimoto, H. L. Clark, and B. John* Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA (Received 6... al. PHYSICAL REVIEW C 70, 014307 (2004) 014307-6 [1] J. P. Blaizot, Phys. Rep. 64, 171 (1980). [2] S. Stringari, Phys. Lett. 108, 232 (1982). [3] Y.-W. Lui, D. H. Youngblood, Y. Tokimoto, H. L. Clark, and B. John, Phys. Rev. C 69, 034611 (2004...

  5. Valley splitting theory of SiGe/Si/SiGe quantum wells Mark Friesen,1,

    E-Print Network [OSTI]

    Coppersmith, Susan N.

    Valley splitting theory of SiGe/Si/SiGe quantum wells Mark Friesen,1, * Sucismita Chutia,1 Charles an effective mass theory for SiGe/Si/SiGe quantum wells, with an emphasis on calculating the valley splitting interface, with characteristic energy splittings of order 0.1­1 meV for the case of SiGe/Si/SiGe quantum

  6. Process for the manufacture of 117Sn diethylenetriaminepentaacetic acids

    DOE Patents [OSTI]

    Srivastava, Suresh C. (Setauket, NY); Li, Zizhong (Upton, NY); Meinken, George (Middle Island, NY)

    2003-01-01T23:59:59.000Z

    Novel methods are provided for the manufacture of .sup.117m Sn(Sn.sup.4+) DTPA. The method allows the use of DTPA, a toxic chelating agent, in an approximately 1:1 ratio to .sup.117m Sn(Sn.sup.4+) via either aqueous conditions, or using various organic solvents, such as methylene chloride. A pharmaceutical composition manufactured by the novel method is also provided, as well as methods for treatment of bone tumors and pain associated with bone cancer using the pharmaceutical composition of the invention.

  7. Elastic anisotropy in multifilament Nb3Sn superconducting wires

    E-Print Network [OSTI]

    Scheuerlein, C; Alknes, P; Arnau, G; Bjoerstad, R; Bordini, B

    2015-01-01T23:59:59.000Z

    The elastic anisotropy caused by the texture in the Nb3Sn filaments of PIT and RRP wires has been calculated by averaging the estimates of Voigt and Reuss, using published Nb3Sn single crystal elastic constants and the Nb3Sn grain orientation distribution determined in both wire types by Electron Backscatter Diffraction. At ambient temperature the calculated Nb3Sn E-moduli in axial direction in the PIT and the RRP wire are 130 GPa and 140 GPa, respectively. The calculated E-moduli are compared with tensile test results obtained for the corresponding wires and extracted filament bundles.

  8. Rolling up SiGe on insulator

    SciTech Connect (OSTI)

    Cavallo, F.; Songmuang, R.; Ulrich, C.; Schmidt, O. G. [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany)

    2007-05-07T23:59:59.000Z

    SiGe on insulator films of 10-50 nm thickness are fabricated by Ge condensation applying different oxidation times. The layers are released from the substrate by selectively etching the insulator film. Due to the varying Ge composition, the layers bend downward toward the substrate surface and roll up into microtubes. Depending on the Ge condensation, the strain distribution in the SiGe layers varies and allows a scaling of the tube diameters between 1 and 4 {mu}m. Assuming pseudomorphic SiGe layers, the tube diameters are smaller than expected from continuum mechanical theory. This suggests the occurrence of additional strain in the oxidized films.

  9. Whisker formation in Sn and Pb-Sn coatings: Role of intermetallic growth, stress evolution, and plastic deformation processes

    SciTech Connect (OSTI)

    Chason, E.; Jadhav, N.; Kumar, K. S. [Division of Engineering, Brown University, Providence, Rhode Island 02912 (United States); Chan, W. L. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Reinbold, L. [Raytheon Company IDS, Maritime Mission Center, Portsmouth, Rhode Island 02871 (United States)

    2008-04-28T23:59:59.000Z

    We have simultaneously measured the evolution of intermetallic volume, stress, and whisker density in Sn and Pb-Sn alloy layers on Cu to study the fundamental mechanisms controlling whisker formation. For pure Sn, the stress becomes increasingly compressive and then saturates, corresponding to a plastically deformed region spreading away from the growing intermetallic particles. Whisker nucleation begins after the stress saturates. Pb-Sn layers have similar intermetallic growth kinetics but the resulting stress and whisker density are much less. Measurements after sputtering demonstrate the important role of the surface oxide in inhibiting stress relaxation.

  10. 136Sn and three body forces

    E-Print Network [OSTI]

    M. Saha Sarkar; S. Sarkar

    2014-11-10T23:59:59.000Z

    New experimental data on 2+ energies of 136,138Sn confirms the trend of lower 2+ excitation energies of even-even tin isotopes with N > 82 compared to those with N 4+)) of these nuclei, simultaneously, apart from one whose matrix elements have been changed empirically to produce mixed seniority states by weakening pairing. We have shown that the experimental result also shows good agreement with the theory in which three body forces have been included in a realistic interaction. The new theoretical results on transition probabilities have been discussed to identify the experimental quantities which will clearly distinguish between different views.

  11. SNAP:SN (Discrete Ordinates) Application Proxy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection245C Unlimited ReleaseWelcome to theAbsorptionFinalSNAP:SN (Discrete

  12. Acoustoelectric effects in very high-mobility p-SiGe/Ge/SiGe heterostructure

    SciTech Connect (OSTI)

    Drichko, I. L.; Diakonov, A. M.; Lebedeva, E. V.; Smirnov, I. Yu. [A. F. Ioffe Physico-Technical Institute of Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation); Mironov, O. A. [Warwick SEMINANO R and D Centre, University of Warwick Science Park, Coventry CV4 7EZ (United Kingdom); Kummer, M.; Kaenel, H. von [Laboratorium fuer Festkoerperphysik ETH Zuerich, CH-8093 Zuerich (Switzerland); EpiSpeed SA, Technoparkstrasse 1, CH-8005 Zuerich (Switzerland)

    2009-11-01T23:59:59.000Z

    Measurement results of the acoustoelectric effects [surface acoustic waves (SAW) attenuation and velocity] in a high-mobility p-SiGe/Ge/SiGe structure are presented. The structure was low-energy plasma-enhanced chemical vapor deposition grown with a two-dimensional (2D) channel buried in the strained Ge layer. The measurements were performed as a function of temperature (1.5-4.2 K) and magnetic field (up to 8.4 T) at different SAW intensities at frequencies 28 and 87 MHz. Shubnikov-de Haas-like oscillations of both SAW attenuation and the velocity change have been observed. Hole density and mobility, effective mass, quantum and transport relaxation times, as well as the Dingle temperature were measured with a method free of electric contacts. The effect of heating of the 2D hole gas by the electric field of the SAW was investigated. Energy relaxation time tau{sub e}psilon and the deformation potential constant determined.

  13. LIMITS OF Nb3Sn ACCELERATOR MAGNETS

    SciTech Connect (OSTI)

    Caspi, Shlomo; Ferracin, Paolo

    2005-05-01T23:59:59.000Z

    Pushing accelerator magnets beyond 10 T holds a promise of future upgrades to machines like the Tevatron at Fermilab and the LHC at CERN. Exceeding the current density limits of NbTi superconductor, Nb{sub 3}Sn is at present the only practical superconductor capable of generating fields beyond 10 T. Several Nb{sub 3}Sn pilot magnets, with fields as high as 16 T, have been built and tested, paving the way for future attempts at fields approaching 20 T. High current density conductor is required to generate high fields with reduced conductor volume. However this significantly increases the Lorentz force and stress. Future designs of coils and structures will require managing stresses of several 100's of MPa and forces of 10's of MN/m. The combined engineering requirements on size and cost of accelerator magnets will involve magnet technology that diverges from the one currently used with NbTi conductor. In this paper we shall address how far the engineering of high field magnets can be pushed, and what are the issues and limitations before such magnets can be used in particle accelerators.

  14. Microstructural evolution of eutectic Au-Sn solder joints

    SciTech Connect (OSTI)

    Song, Ho Geon

    2002-05-31T23:59:59.000Z

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  15. PROBABILITY OF CORRECT SELECTION OF GAMMA VERSUS GE OR WEIBULL VERSUS GE BASED ON

    E-Print Network [OSTI]

    Kundu, Debasis

    PROBABILITY OF CORRECT SELECTION OF GAMMA VERSUS GE OR WEIBULL VERSUS GE BASED ON LIKELIHOOD RATIO proposes the use of likelihood ratio statistic in choosing between gamma and GE models or between Weibull and GE models. Probability of correct selec- tions are obtained using Monte Carlo simulations for various

  16. Performance analysis of HD1: a 16 Tesla Nb3Sn dipole Magnet

    E-Print Network [OSTI]

    Mattafirri, S.

    2009-01-01T23:59:59.000Z

    Analysis of HD1: A 16 Tesla Nb 3 Sn Dipole Magnet S.of HD1b, an Upgraded 16 Tesla Nb 3 Sn Dipole Magnet”, This

  17. Understanding and engineering of NiGe/Ge junction formed by phosphorus ion implantation after germanidation

    SciTech Connect (OSTI)

    Oka, Hiroshi, E-mail: oka@asf.mls.eng.osaka-u.ac.jp; Minoura, Yuya; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji [Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2014-08-11T23:59:59.000Z

    Modulation of the effective electron Schottky barrier height (eSBH) of NiGe/Ge contacts induced by phosphorus ion implantation after germanide formation was investigated by considering local inhomogeneity in the eSBH. Systematic studies of NiGe/Ge contact devices having various germanide thicknesses and ion implantation areas indicated the threshold dopant concentration at the NiGe/Ge interface required for eSBH modulation and negligible dopant diffusion even at NiGe/Ge interface during drive-in annealing, leading to variation in the eSBH between the bottom and sidewall portions of the NiGe regions. Consequently, this method makes it possible to design source/drain contacts with low-resistivity Ohmic and ideal rectifying characteristics for future Ge-based transistors.

  18. Ternary PtSnRhSnO2 nanoclusters: synthesis and electroactivity for ethanol oxidation fuel cell reaction

    E-Print Network [OSTI]

    Frenkel, Anatoly

    Ternary PtSnRh­SnO2 nanoclusters: synthesis and electroactivity for ethanol oxidation fuel cell. Ethanol becomes an attractive fuel in the fuel cell reactions compared with methanol and hydrogen, because­4 A major impediment to the commercialization of ethanol fuel cell stacks is the difficulty in designing

  19. Yb{sub 5}Ni{sub 4}Sn{sub 10} and Yb{sub 7}Ni{sub 4}Sn{sub 13}: New polar intermetallics with 3D framework structures

    SciTech Connect (OSTI)

    Lei Xiaowu; Sun Zhongming; Li Longhua [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Zhong Guohua; Hu Chunli [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Mao Jianggao, E-mail: mjg@fjirsm.ac.c [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)

    2010-04-15T23:59:59.000Z

    The title compounds have been obtained by solid state reactions of the corresponding pure elements at high temperature, and structurally characterized by single-crystal X-ray diffraction studies. Yb{sub 5}Ni{sub 4}Sn{sub 10} adopts the Sc{sub 5}Co{sub 4}Si{sub 10} structure type and crystallizes in the tetragonal space group P4/mbm (No. 127) with cell parameters of a=13.785(4) A, c=4.492 (2) A, V=853.7(5) A{sup 3}, and Z=2. Yb{sub 7}Ni{sub 4}Sn{sub 13} is isostructural with Yb{sub 7}Co{sub 4}InGe{sub 12} and crystallizes in the tetragonal space group P4/m (No. 83) with cell parameters of a=11.1429(6) A, c=4.5318(4) A, V=562.69(7) A{sup 3}, and Z=1. Both structures feature three-dimensional (3D) frameworks based on three different types of one-dimensional (1D) channels, which are occupied by the Yb atoms. Electronic structure calculations based on density functional theory (DFT) indicate that both compounds are metallic. These results are in agreement with those from temperature-dependent resistivity and magnetic susceptibility measurements. - Graphical abstract: Two new ytterbium nickel stannides, namely, Yb{sub 5}Ni{sub 4}Sn{sub 10} and Yb{sub 7}Ni{sub 4}Sn{sub 13}, have been synthesized and structurally characterized by single-crystal X-ray diffraction studies. Both their structures feature three-dimensional (3D) frameworks based on three different types of one-dimensional (1D) channels, which are situated by all the Yb atoms. Electronic structure calculations based on density functional theory (DFT) indicate that both compounds are metallic, which are in accordance with the results from temperature-dependent resistivity and magnetic susceptibility measurements.

  20. SiGe-On-Insulator (SGOI) Technology and MOSFET Fabrication

    E-Print Network [OSTI]

    SiGe-On-Insulator (SGOI) Technology and MOSFET Fabrication Zhiyuan Cheng, E. A. Fitzgerald, and D with less defects in SiGe film, but the SiGe film uniformity is inferior. "Smart-cut" approach has better control on the SiGe film thickness and uniformity, and is applicable to wider Ge content range of the SiGe

  1. A panchromatic view of the restless SN 2009ip reveals the explosive ejection of a massive star envelope

    SciTech Connect (OSTI)

    Margutti, R.; Milisavljevic, D.; Soderberg, A. M.; Chornock, R.; Zauderer, B. A.; Sanders, N. E.; Berger, E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Murase, K. [Institute for Advanced Study, Princeton, NJ 08540 (United States); Guidorzi, C. [Department of Physics, University of Ferrara, via Saragat 1, I-44122 Ferrara (Italy); Kuin, P. [University College London, MSSL, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Fransson, C. [Department of Astronomy and the Oskar Klein Centre, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Levesque, E. M. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Chandra, P.; Challis, P. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune University Campus, Ganeshkhind, Pune 411007 (India); Bianco, F. B. [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Brown, P. J. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A. and M. University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States); Chatzopoulos, E. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712-1205 (United States); Cheung, C. C. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Choi, C. [CEOU/Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Chomiuk, L. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); and others

    2014-01-01T23:59:59.000Z

    The double explosion of SN 2009ip in 2012 raises questions about our understanding of the late stages of massive star evolution. Here we present a comprehensive study of SN 2009ip during its remarkable rebrightenings. High-cadence photometric and spectroscopic observations from the GeV to the radio band obtained from a variety of ground-based and space facilities (including the Very Large Array, Swift, Fermi, Hubble Space Telescope, and XMM) constrain SN 2009ip to be a low energy (E ? 10{sup 50} erg for an ejecta mass ?0.5 M {sub ?}) and asymmetric explosion in a complex medium shaped by multiple eruptions of the restless progenitor star. Most of the energy is radiated as a result of the shock breaking out through a dense shell of material located at ?5 × 10{sup 14} cm with M ? 0.1 M {sub ?}, ejected by the precursor outburst ?40 days before the major explosion. We interpret the NIR excess of emission as signature of material located further out, the origin of which has to be connected with documented mass-loss episodes in the previous years. Our modeling predicts bright neutrino emission associated with the shock break-out if the cosmic-ray energy is comparable to the radiated energy. We connect this phenomenology with the explosive ejection of the outer layers of the massive progenitor star, which later interacted with material deposited in the surroundings by previous eruptions. Future observations will reveal if the massive luminous progenitor star survived. Irrespective of whether the explosion was terminal, SN 2009ip brought to light the existence of new channels for sustained episodic mass loss, the physical origin of which has yet to be identified.

  2. ASYMMETRIC EJECTA DISTRIBUTION IN SN 1006

    SciTech Connect (OSTI)

    Uchida, Hiroyuki; Koyama, Katsuji [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Yamaguchi, Hiroya, E-mail: uchida@cr.scphys.kyoto-u.ac.jp [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2013-07-01T23:59:59.000Z

    We present the results from deep X-ray observations ({approx}400 ks in total) of SN 1006 with Suzaku. The thermal spectrum from the entire supernova remnant (SNR) exhibits prominent emission lines of O, Ne, Mg, Si, S, Ar, Ca, and Fe. The observed abundance pattern in the ejecta components is in good agreement with that predicted by a standard model of Type Ia supernovae (SNe). The spatially resolved analysis reveals that the distribution of the O-burning and incomplete Si-burning products (Si, S, and Ar) is asymmetric, while that of the C-burning products (O, Ne, and Mg) is relatively uniform in the SNR interior. The peak position of the former is clearly shifted by 5' ({approx}3.2 pc at the distance of 2.2 kpc) to the southeast (SE) from the SNR's geometric center. Using the SNR age of {approx}1000 yr, we constrain that the velocity asymmetry (in projection) of the ejecta is {approx}3100 km s{sup -1}. The Fe abundance is also significantly higher in the SE region than in the northwest. Given that the non-uniformity is observed only in the heavier elements (Si through Fe), we argue that SN 1006 originates from an asymmetric explosion, as is expected from recent multidimensional simulations of Type Ia SNe, although we cannot eliminate the possibility that inhomogeneous ambient medium had induced the apparent non-uniformity. Possible evidence for the Cr-K-shell line and line broadening in the Fe-K-shell emission is also found.

  3. About GE Global Research Center | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy,ARMForms About Become agovEducationWelcome toAboutAbout GE Global Research

  4. Heat Transfer in GE Jet Engines | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cn SunnybankD.jpgHanfordDepartment ofHeat Transfer in GE Jet Engines Click to

  5. Early-Phase Spectra of "Hypernova" SN 2002ap

    E-Print Network [OSTI]

    K. Kinugasa; H. Kawakita; K. Ayani; T. Kawabata; H. Yamaoka; J. S. Deng; P. A. Mazzali; K. Maeda; K. Nomoto

    2002-08-29T23:59:59.000Z

    The spectral evolution of the peculiar SN Ic 2002ap during the first 40 days is presented. The spectra display very broad absorption features, which are typical of "hypernovae". The maximum expansion velocity measured on the earliest spectra exceeds 3 times 10^4 km s^{-1}. The spectrum of SN 2002ap at the epoch of maximum brightness resembles that of SN 1997ef more than that of SN 1998bw. The spectral evolution of SN 2002ap proceeds at about 1.5 times the rate of SN 1997ef. The parameterized supernova spectrum synthesis code SYNOW was used to perform line identification and deduce velocity information from the early-phase spectra, which are heavily affected by line blending. The photospheric velocity, as deduced from the fitting results and from the blueshift of the \\ion{Si}{2} lambda 6355 absorption minimum, is lower than in previously studied hypernovae. At advanced epochs, the \\ion{Si}{2} lambda 6355 absorption minimum becomes difficult to distinguish. This may be caused by the growth of [\\ion{O}{1}] lambda lambda 6300, 6364 emission. Together with the rapid spectral evolution, this suggests that SN 2002ap should enter the nebular phase sooner than previously studied hypernovae.

  6. snIEA User Survey 2005-06snIEA User Survey 2005-06 Page:12Page:12 (c) Mercator(c) Mercator SNAPSNAP

    E-Print Network [OSTI]

    Fernandez, Eduardo

    snIEA User Survey 2005-06snIEA User Survey 2005-06 Page:12Page:12 (c) Mercator(c) Mercator SNAPSNAP.0% 1 5.0% - - 1 5.0% #12;snIEA User Survey 2005-06snIEA User Survey 2005-06 Page:13Page:13 (c) Mercator.0% 5 25.0% - - - - 1 5.0% #12;snIEA User Survey 2005-06snIEA User Survey 2005-06 Page:14Page:14 (c

  7. Combustion Synthesis and Characterization of Nanocrystalline Tin and Tin Oxide (SnOx, x 02) Particles

    E-Print Network [OSTI]

    Wooldridge, Margaret S.

    Combustion Synthesis and Characterization of Nanocrystalline Tin and Tin Oxide (SnOx, x 0 the concentration of oxygen in the reactant gases and the flame temperatures, metallic tin (Sn), tin monoxide (romarchite SnO), and/or tin dioxide (cassiterite SnO2) were generated. The crystalline powders consisted

  8. In situ visualization of metallurgical reactions in nanoscale Cu/Sn diffusion couples

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yin, Qiyue; Stach, Eric A.; Gao, Fan; Zhou, Guangwen; Gu, Zhiyong

    2015-01-01T23:59:59.000Z

    The Cu–Sn metallurgical soldering reaction in two-segmented Cu–Sn nanowires is visualized by in-situ transmission electron microscopy. By varying the relative lengths of Cu and Sn segments, we show that the metallurgical reaction starts at ~ 200 ° with the formation of a Cu–Sn solid solution for the Sn/Cu length ratio smaller than 1:5 while the formation of Cu–Sn intermetallic compounds (IMCs) for larger Sn/Cu length ratios. Upon heating the nanowires up to ~ 500 °C, two phase transformation pathways occur, ?-Cu?Sn? ? ?-Cu?Sn ? ?-Cu??Sn?? for nanowires with a long Cu segment and ?-Cu?Sn? ? ?-Cu?Sn ? ?-Cu?Sn with amore »short Cu segment. The dynamic in situ TEM visualization of the evolution of Kirkendall voids demonstrates that Cu diffuses faster both in Sn and IMCs than that of Sn in Cu? and IMCs, which is the underlying cause of the dependence of the IMC formation and associated phase evolution on the relative lengths of the Cu and Sn segments.« less

  9. Photoconductivity of Si/Ge multilayer structures with Ge quantum dots pseudomorphic to the Si matrix

    SciTech Connect (OSTI)

    Talochkin, A. B., E-mail: tal@thermo.isp.nsc.ru; Chistokhin, I. B. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

    2011-07-15T23:59:59.000Z

    Longitudinal photoconductivity spectra of Si/Ge multilayer structures with Ge quantum dots grown pseudomorphically to the Si matrix are studied. Lines of optical transitions between hole levels of quantum dots and Si electronic states are observed. This allowed us to construct a detailed energy-level diagram of electron-hole levels of the structure. It is shown that hole levels of pseudomorphic Ge quantum dots are well described by the simplest 'quantum box' model using actual sizes of Ge islands. The possibility of controlling the position of the long-wavelength photosensitivity edge by varying the growth parameters of Si/Ge structures with Ge quantum dots is determined.

  10. PHYSICAL REVIEW B 87, 115208 (2013) Cu2Zn(Sn,Ge)Se4 and Cu2Zn(Sn,Si)Se4 alloys as photovoltaic materials

    E-Print Network [OSTI]

    Gong, Xingao

    2013-01-01T23:59:59.000Z

    , China 2 Key Laboratory of Polar Materials and Devices (MOE), East China Normal University, Shanghai 200241, China 3 National Renewable Energy Laboratory, Golden, Colorado 80401, USA (Received 16 January of the solar cell light absorber. However, material properties of these alloys as functions of alloy

  11. Advanced Analytics | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWP TWP Related LinksATHENAAdministrative80-AA (01-2015)GE

  12. Characterization of Nb?Sn superconducting strand under pure bending

    E-Print Network [OSTI]

    Harris, David L., S.M. Massachusetts Institute of Technology

    2005-01-01T23:59:59.000Z

    Characterizing the strain-dependent behavior of technological Nb?Sn superconducting strand has been an important subject of research for the past 25 years. Most of the effort has focused on understanding the uniaxial tension ...

  13. Weak topological insulators in PbTe/SnTe superlattices

    E-Print Network [OSTI]

    Yang, Gang

    It is desirable to realize topological phases in artificial structures by engineering electronic band structures. In this paper we investigate (PbTe)[subscript m](SnTe)[subscript 2n?m] superlattices along the [001] direction ...

  14. Critical Current Metrology for Nb3Sn Conductor Development

    SciTech Connect (OSTI)

    Goodrich, Loren F. [NIST

    2013-12-13T23:59:59.000Z

    The research is focused on the variable temperature studies of high-performance Nb3Sn and other high-field conductors for the next-generation of HEP magnets.

  15. Performance Comparison of Nb3Sn Magnets at LBNL

    E-Print Network [OSTI]

    Chiesa, L.

    2011-01-01T23:59:59.000Z

    2LCOI SC-MAG#722 LBNL-49917 Performance Comparison ofNb 3 Sn Magnets at LBNL L. Chiesa, S. Caspi, M . Coccoli,the Superconducting Magnet Group at LBNL has been developing

  16. Thermal Imaging Technologies | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Enables Advanced Thermal Imaging An error occurred. Unable to execute Javascript. Bryan Whalen in the Electronics Cooling Lab at GE Global Research recorded this thermo...

  17. Supernova 1996cr: SN 1987A's Wild Cousin?

    E-Print Network [OSTI]

    F. E. Bauer; V. V. Dwarkadas; W. N. Brandt; S. Immler; S. Smartt; N. Bartel; M. F. Bietenholz

    2008-05-06T23:59:59.000Z

    We report on new VLT optical spectroscopic and multi-wavelength archival observations of SN1996cr, a previously identified ULX known as Circinus Galaxy X-2. Our optical spectrum confirms SN1996cr as a bona fide type IIn SN, while archival imaging isolates its explosion date to between 1995-02-28 and 1996-03-16. SN1996cr is one of the closest SNe (~3.8 Mpc) in the last several decades and in terms of flux ranks among the brightest radio and X-ray SNe ever detected. The wealth of optical, X-ray, and radio observations that exist for this source provide relatively detailed constraints on its post-explosion expansion and progenitor history, including an preliminary angular size constaint from VLBI. The archival X-ray and radio data imply that the progenitor of SN1996cr evacuated a large cavity just prior to exploding: the blast wave likely expanded for ~1-2 yrs before eventually striking the dense circumstellar material which surrounds SN1996cr. The X-ray and radio emission, which trace the progenitor mass-loss rate, have respectively risen by a factor of ~2 and remained roughly constant over the past 7 yr. This behavior is reminiscent of the late rise of SN1987A, but 1000 times more luminous and much more rapid to onset. Complex Oxygen line emission in the optical spectrum further hints at a possible concentric shell or ring-like structure. The discovery of SN1996cr suggests that a substantial fraction of the closest SNe observed in the last several decades have occurred in wind-blown bubbles. An Interplanetary Network position allows us to reject a tentative GRB association with BATSE 4B960202. [Abridged

  18. Limited-area growth of Ge and SiGe on Si

    E-Print Network [OSTI]

    Kim, Meekyung, Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    The goal of this thesis is to develop and understand processing conditions that improve the surface morphology and reduce the dislocation density in limited-area heteroepitaxy of Ge and SiGe on Si (100) substrates. Low ...

  19. SiGe/sSi quantum dot electron spin decoherence dependence on $^{73}$Ge

    E-Print Network [OSTI]

    Witzel, Wayne M; Carroll, Malcolm S

    2011-01-01T23:59:59.000Z

    We theoretically study the nuclear spin induced decoherence of a quantum dot in Si that is confined at a SiGe interface. We calculate decoherence time dependence on $^{73}$Ge in the barrier layer to evaluate the importance of Ge as well as Si enrichment for long decoherence times. We use atomistic tight-binding modeling for an accurate account of the electron wavefunction which is particularly important for determining the contact hyperfine interactions with the Ge nuclear spins. We find decoherence times due to Ge spins at natural concentrations to be milliseconds. This suggests SiGe/sSi quantum dot devices employing enriched Si will require enriched Ge as well in order to benefit from long coherence times. We provide a comparison of $T_2$ times for various fractions of nonzero spin isotopes of Si and Ge.

  20. SiGe/Si quantum dot electron spin decoherence dependence on $^{73}$Ge

    E-Print Network [OSTI]

    Wayne M. Witzel; Rajib Rahman; Malcolm S. Carroll

    2012-05-14T23:59:59.000Z

    We theoretically study the nuclear spin induced decoherence of a quantum dot in Si that is confined at a SiGe interface. We calculate decoherence time dependence on $^{73}$Ge in the barrier layer to evaluate the importance of Ge as well as Si enrichment for long decoherence times. We use atomistic tight-binding modeling for an accurate account of the electron wavefunction which is particularly important for determining the contact hyperfine interactions with the Ge nuclear spins. We find decoherence times due to Ge spins at natural concentrations to be milliseconds. This suggests SiGe/Si quantum dot devices employing enriched Si will require enriched Ge as well in order to benefit from long coherence times. We provide a comparison of $T_2$ times for various fractions of nonzero spin isotopes of Si and Ge.

  1. MOSFET Channel Engineering using Strained Si, SiGe, and Ge Channels

    E-Print Network [OSTI]

    Fitzgerald, Eugene A.

    Biaxial tensile strained Si grown on SiGe virtual substrates will be incorporated into future generations of CMOS technology due to the lack of performance increase with scaling. Compressively strained Ge-rich alloys with ...

  2. Enhanced Hole Mobility in High Ge Content Asymmetrically Strained-SiGe p-MOSFETs

    E-Print Network [OSTI]

    Chléirigh, C. Ni

    The hole mobility characteristics of ?110? /(100)-oriented asymmetrically strained-SiGe p-MOSFETs are studied.

  3. Optical observations of a SN 2002cx-like peculiar supernova SN 2013en in UGC 11369

    E-Print Network [OSTI]

    Liu, Zheng-Wei; Ciabattari, Fabrizio; Tomasella, Lina; Wang, Xiaofeng; Zhao, Xulin; Zhang, Tianmeng; Xin, Yuxin; Wang, ChuanJun; Chang, Liang

    2015-01-01T23:59:59.000Z

    We present optical observations of a SN 2002cx-like supernova SN 2013en in UGC 11369, spanning from a phase near maximum light (t= +1 d) to t= +60 d with respect to the R-band maximum. Adopting a distance modulus of mu=34.11 +/- 0.15 mag and a total extinction (host galaxy+Milky Way) of $A_V \\sim1.5$ mag, we found that SN 2013en peaked at $M(R)\\sim -18.6$ mag, which is underluminous compared to the normal SNe Ia. The near maximum spectra show lines of Si II, Fe II, Fe III, Cr II, Ca II and other intermediate-mass and iron group elements which all have lower expansion velocities (i.e., ~ 6000 km/s). The photometric and spectroscopic evolution of SN 2013en is remarkably similar to those of SN 2002cx and SN 2005hk, suggesting that they are likely to be generated from a similar progenitor scenario or explosion mechanism.

  4. Modeling of GE Appliances: Final Presentation

    SciTech Connect (OSTI)

    Fuller, Jason C.; Vyakaranam, Bharat; Leistritz, Sean M.; Parker, Graham B.

    2013-01-31T23:59:59.000Z

    This report is the final in a series of three reports funded by U.S. Department of Energy Office of Electricity Delivery and Energy Reliability (DOE-OE) in collaboration with GE Appliances’ through a Cooperative Research and Development Agreement (CRADA) to describe the potential of GE Appliances’ DR-enabled appliances to provide benefits to the utility grid.

  5. Relaxed SiGe Layers with High Ge Content by Compliant Substrates , R.L. Peterson1

    E-Print Network [OSTI]

    Relaxed SiGe Layers with High Ge Content by Compliant Substrates H. Yin1 , R.L. Peterson1 , K, high Ge content SiGe layers have been realized using stress balance on a compliant under compression. Upon equilibrium after an annealing, stress balance was formed between the SiGe films

  6. Effects of Interface Disorder on Valley Splitting in SiGe/Si/SiGe Quantum Wells

    E-Print Network [OSTI]

    Zhengping Jiang; Neerav Kharche; Timothy Boykin; Gerhard Klimeck

    2012-03-06T23:59:59.000Z

    A sharp potential barrier at the Si/SiGe interface introduces valley splitting (VS), which lifts the 2-fold valley degeneracy in strained SiGe/Si/SiGe quantum wells (QWs). This work examines in detail the effects of Si/SiGe interface disorder on the VS in an atomistic tight binding approach based on statistical sampling. VS is analyzed as a function of electric field, QW thickness, and simulation domain size. Strong electric fields push the electron wavefunctions into the SiGe buffer and introduce significant VS fluctuations from device to device. A Gedankenexperiment with ordered alloys sheds light on the importance of different bonding configurations on VS. We conclude that a single SiGe band offset and effective mass cannot comprehend the complex Si/SiGe interface interactions that dominate VS.

  7. Effects of Interface Disorder on Valley Splitting in SiGe/Si/SiGe Quantum Wells

    E-Print Network [OSTI]

    Jiang, Zhengping; Boykin, Timothy; Klimeck, Gerhard

    2011-01-01T23:59:59.000Z

    A sharp potential barrier at the Si/SiGe interface introduces valley splitting (VS), which lifts the 2-fold valley degeneracy in strained SiGe/Si/SiGe quantum wells (QWs). This work examines in detail the effects of Si/SiGe interface disorder on the VS in an atomistic tight binding approach based on statistical sampling. VS is analyzed as a function of electric field, QW thickness, and simulation domain size. Strong electric fields push the electron wavefunctions into the SiGe buffer and introduce significant VS fluctuations from device to device. A Gedankenexperiment with ordered alloys sheds light on the importance of different bonding configurations on VS. We conclude that a single SiGe band offset and effective mass cannot comprehend the complex Si/SiGe interface interactions that dominate VS.

  8. Monolithic Ge-on-Si lasers for integrated photonics

    E-Print Network [OSTI]

    Liu, Jifeng

    We report room temperature Ge-on-Si lasers with direct gap emission at 1590-1610 nm. Modeling of Ge/Si double heterojunction structures, which is supported by experimental results of Ge/Si LEDs, indicates the feasibility ...

  9. Ge-on-Si laser for silicon photonics

    E-Print Network [OSTI]

    Camacho-Aguilera, Rodolfo Ernesto

    2013-01-01T23:59:59.000Z

    Ge-on-Si devices are explored for photonic integration. Importance of Ge in photonics has grown and through techniques developed in our group we demonstrated low density of dislocations (Ge ...

  10. Is there a risk from not using GE animals?

    E-Print Network [OSTI]

    Murray, James D.; Maga, Elizabeth A.

    2010-01-01T23:59:59.000Z

    Is there a risk from not using GE animals? James D. Murray •rst genetically engi- neered (GE) plants and animals forthe debate often focuses on GE as a technique that is used

  11. Germanium: From Its Discovery to SiGe Devices

    E-Print Network [OSTI]

    Haller, E.E.

    2006-01-01T23:59:59.000Z

    From Its Discovery to SiGe Devices E.E. Haller Department ofrapidly rising interest in SiGe alloys, we are just startingstrained and unstrained SiGe multilayer structures [58]. 9.

  12. Scaling of SiGe Heterojunction Bipolar Transistors

    E-Print Network [OSTI]

    Rieh, Jae-Sung

    Scaling of SiGe Heterojunction Bipolar Transistors JAE-SUNG RIEH, SENIOR MEMBER, IEEE, DAVID-century. This paper inves- tigates the impacts of scaling on SiGe heterojunction bipolar tran- sistors (HBTs), which), epitaxial-base Si BJTs (Epi Si BJT), SiGe HBTs (SiGe HBT), and SiGe HBTs with carbon-doped base (SiGeC HBT

  13. Superconducting and magnetic properties of Sr?Ir?Sn??

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Biswas, P. K.; Wang, Kefeng; Amato, A.; Khasanov, R.; Luetkens, H.; Petrovic, C.; Cook, R. M.; Lees, M. R.; Morenzoni, E.

    2014-10-01T23:59:59.000Z

    Magnetization and muon spin relaxation or rotation (µSR) measurements have been performed to study the superconducting and magnetic properties of Sr?Ir?Sn??. From magnetization measurements the lower and upper critical fields of Sr?Ir?Sn?? are found to be 81(1) Oe and 14.4(2) kOe, respectively. Zero-field µSR data show no sign of any magnetic ordering or weak magnetism in Sr?Ir?Sn??. Transverse-field µSR measurements in the vortex state provided the temperature dependence of the magnetic penetration depth ?. The dependence of ??² with temperature is consistent with the existence of single s-wave energy gap in the superconducting state of Sr?Ir?Sn?? with a gap valuemore »of 0.82(2) meV at absolute zero temperature. The magnetic penetration depth at zero temperature ?(0) is 291(3) nm. The ratio ?(0)/kBTc = 2.1(1) indicates that Sr?Ir?Sn?? should be considered as a strong-coupling superconductor.« less

  14. The magnification of SN 1997ff, the farthest known supernova

    SciTech Connect (OSTI)

    Benitez, Narciso; Riess, Adam; Nugent, Peter; Dickinson, Mark; Chornock, Ryan; Filippenko, Alexei V.

    2002-09-03T23:59:59.000Z

    With a redshift of z {approx} 1.7, SN 1997ff is the most distant type Ia supernova discovered so far. This SN is close to several bright, z = 0.6-0.9 galaxies, and we consider the effects of lensing by those objects on the magnitude of SN 1997ff. We estimate their velocity dispersions using the Tully-Fisher and Faber-Jackson relations corrected for evolution effects, and calculate, applying the multiple-plane lensing formalism, that SN 1997ff is magnified by 0.34{+-}0.12 mag. Due to the spatial configuration of the foreground galaxies, the shear from individual lenses partially cancels out,and the total distortion induced on the host galaxy is considerably smaller than that produced by a single lens having the same magnification. After correction for lensing, the revised distance to SN 1997ff is m-M = 45.49 {+-} 0.34 mag, which improves the agreement with the {Omega}{sub M} = 0.35, {Omega}{Lambda} = 0.65 cosmology expected from lower-redshift SNe Ia, and is inconsistent at the {approx} 3 sigma confidence level with a uniform gray dust model or a simple evolution model.

  15. Superconducting and magnetic properties of Sr?Ir?Sn??

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Biswas, P. K. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Wang, Kefeng [Brookhaven National Lab. (BNL), Upton, NY (United States); Amato, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Khasanov, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Luetkens, H. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Petrovic, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cook, R. M. [Univ. of Warwick, Coventry (United Kingdom); Lees, M. R. [Univ. of Warwick, Coventry (United Kingdom); Morenzoni, E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    2014-10-01T23:59:59.000Z

    Magnetization and muon spin relaxation or rotation (µSR) measurements have been performed to study the superconducting and magnetic properties of Sr?Ir?Sn??. From magnetization measurements the lower and upper critical fields of Sr?Ir?Sn?? are found to be 81(1) Oe and 14.4(2) kOe, respectively. Zero-field µSR data show no sign of any magnetic ordering or weak magnetism in Sr?Ir?Sn??. Transverse-field µSR measurements in the vortex state provided the temperature dependence of the magnetic penetration depth ?. The dependence of ??² with temperature is consistent with the existence of single s-wave energy gap in the superconducting state of Sr?Ir?Sn?? with a gap value of 0.82(2) meV at absolute zero temperature. The magnetic penetration depth at zero temperature ?(0) is 291(3) nm. The ratio ?(0)/kBTc = 2.1(1) indicates that Sr?Ir?Sn?? should be considered as a strong-coupling superconductor.

  16. Understanding of interface structures and reaction mechanisms induced by Ge or GeO diffusion in Al{sub 2}O{sub 3}/Ge structure

    SciTech Connect (OSTI)

    Shibayama, Shigehisa [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan) [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); JSPS, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Kato, Kimihiko; Sakashita, Mitsuo; Takeuchi, Wakana; Taoka, Noriyuki; Nakatsuka, Osamu; Zaima, Shigeaki [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)] [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-08-19T23:59:59.000Z

    The reaction mechanisms at Al{sub 2}O{sub 3}/Ge interfaces with thermal oxidation through the Al{sub 2}O{sub 3} layer have been investigated. X-ray photoelectron spectroscopy reveals that an Al{sub 6}Ge{sub 2}O{sub 13} layer is formed near the interface, and a GeO{sub 2} layer is formed on the Al{sub 2}O{sub 3} surface, suggesting Ge or GeO diffusion from the Ge surface. It is also clarified that the Al{sub 6}Ge{sub 2}O{sub 13} layer is formed by the different mechanism with a small activation energy of 0.2 eV, compared with the GeO{sub 2} formation limited by oxygen diffusion. Formation of Al-O-Ge bonds due to the AlGeO formation could lead appropriate interface structures with high interface qualities.

  17. Magnetic and magnetocaloric properties of Mn{sub 4–x}Fe{sub x}Ga?Sn

    SciTech Connect (OSTI)

    Eichenberger, L.; Malaman, B.; Mazet, T., E-mail: thomas.mazet@univ-lorraine.fr [Institut Jean Lamour, CNRS UMR 7198, Université de Lorraine, B.P. 70239, 54506 Vandoeuvre-lès-Nancy (France); Huang, J. H. [Baotou Research Institute of Rare Earths, Baotou 014030 (China)

    2014-09-14T23:59:59.000Z

    We investigate the magnetic and magnetocaloric properties of the new Mn{sub 4–x}Fe{sub x}Ga?Sn compounds (x = 0, 0.1, 0.4, 0.6, and 0.8) from DC magnetization measurements. These phases crystallize in a lacunar form of the ?-Fe{sub 2–x}Ge type of structure (P6?/mmc). They present a second-order paramagnetic to ferromagnetic transition whose temperature increases upon increasing the Fe content from TC=317 K for x=0 up to TC=411 K for x=0.8. The alloys with x?0.4 further exhibit another transition at lower temperature associated with a spin reorientation. The maximal magnetization and magnetic entropy change are found almost constant throughout the series close to ~7.4 ?B/f.u. and ~12 mJ cm³ K?¹ (for ???H=2.4 T), respectively. The magnetocaloric properties of Mn{sub 4–x}Fe{sub x}Ga?Sn are compared with those of previously investigated materials with high-temperature magnetic transition and their potential interest for high-temperature magnetocaloric applications is briefly discussed.

  18. Enhancement of thermal stability and water resistance in yttrium-doped GeO{sub 2}/Ge gate stack

    SciTech Connect (OSTI)

    Lu, Cimang, E-mail: cimang@adam.t.u-tokyo.ac.jp; Hyun Lee, Choong; Zhang, Wenfeng; Nishimura, Tomonori; Nagashio, Kosuke; Toriumi, Akira [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656 (Japan); JST, CREST, 7-3-1 Hongo, Tokyo 113-8656 (Japan)

    2014-03-03T23:59:59.000Z

    We have systematically investigated the material and electrical properties of yttrium-doped GeO{sub 2} (Y-GeO{sub 2}) on Germanium (Ge). A significant improvement of both thermal stability and water resistance were demonstrated by Y-GeO{sub 2}/Ge stack, compared to that of pure GeO{sub 2}/Ge stack. The excellent electrical properties of Y-GeO{sub 2}/Ge stacks with low D{sub it} were presented as well as enhancement of dielectric constant in Y-GeO{sub 2} layer, which is beneficial for further equivalent oxide thickness scaling of Ge gate stack. The improvement of thermal stability and water resistance are discussed both in terms of the Gibbs free energy lowering and network modification of Y-GeO{sub 2}.

  19. Engineer Receives UMass "Salute To Service" Award | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    November 22, 2013 - GE Global Research, the technology development arm of the General Electric Company (NYSE: GE), is proud to announce that Dr. Marshall Jones, a world renowned...

  20. Crowdsourcing Wins Manufacturing Leadership 100 | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NY, May 22, 2013 - GE Global Research, the technology development arm of the General Electric Co. (NYSE: GE) today announced that it has won a prestigious Manufacturing Leadership...

  1. Testimonials - Partnerships in Fuel Cells - GE Global Research...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fuel Cells - GE Global Research Testimonials - Partnerships in Fuel Cells - GE Global Research Addthis An error occurred. Unable to execute Javascript. Text Version The words...

  2. Butterfly-Inspired Thermal Imaging | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    primusenginefeaturedimage3 GE Innovation and Manufacturing in Europe 2-4-13-v-3d-printing-medical-devices Additive Manufacturing Demonstration at GE Global Research ...

  3. ME 227 CE 212 MATH 223 GE 210 CMPT 116 ABE 211CHE 210 GE 213# MATH 224

    E-Print Network [OSTI]

    Saskatchewan, University of

    GE 120 ME 227 CE 212 MATH 223 GE 210 CMPT 116 ABE 211CHE 210 GE 213# MATH 224 ABE 295 ABE 212Elective* Elective* AB E 311 ABE 313 ABE 312 GE 348#ABE 323 co-requisite ABE 327 HSS#@ HSS#@ ABE 324 GE 300# ABE 395 4TH YEAR ABE Elec* ABE Elec* ABE Elec*ABE 422 GE 449# Ag Elec* T.E.* T.E.* ABE Elec* Ag Elec

  4. Thermal conductivity of sputtered amorphous Ge films

    SciTech Connect (OSTI)

    Zhan, Tianzhuo; Xu, Yibin; Goto, Masahiro; Tanaka, Yoshihisa; Kato, Ryozo; Sasaki, Michiko; Kagawa, Yutaka [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)] [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)

    2014-02-15T23:59:59.000Z

    We measured the thermal conductivity of amorphous Ge films prepared by magnetron sputtering. The thermal conductivity was significantly higher than the value predicted by the minimum thermal conductivity model and increased with deposition temperature. We found that variations in sound velocity and Ge film density were not the main factors in the high thermal conductivity. Fast Fourier transform patterns of transmission electron micrographs revealed that short-range order in the Ge films was responsible for their high thermal conductivity. The results provide experimental evidences to understand the underlying nature of the variation of phonon mean free path in amorphous solids.

  5. Energy band alignment of atomic layer deposited HfO{sub 2} oxide film on epitaxial (100)Ge, (110)Ge, and (111)Ge layers

    SciTech Connect (OSTI)

    Hudait, Mantu K.; Zhu Yan [Advanced Devices and Sustainable Energy Laboratory (ADSEL), Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2013-03-21T23:59:59.000Z

    Crystallographically oriented epitaxial Ge layers were grown on (100), (110), and (111)A GaAs substrates by in situ growth process using two separate molecular beam epitaxy chambers. The band alignment properties of atomic layer hafnium oxide (HfO{sub 2}) film deposited on crystallographically oriented epitaxial Ge were investigated using x-ray photoelectron spectroscopy (XPS). Valence band offset, {Delta}E{sub v} values of HfO{sub 2} relative to (100)Ge, (110)Ge, and (111)Ge orientations were 2.8 eV, 2.28 eV, and 2.5 eV, respectively. Using XPS data, variation in valence band offset, {Delta}E{sub V}(100)Ge>{Delta}E{sub V}(111)Ge>{Delta}E{sub V}(110)Ge, was obtained related to Ge orientation. Also, the conduction band offset, {Delta}E{sub c} relation, {Delta}E{sub c}(110)Ge>{Delta}E{sub c}(111)Ge>{Delta}E{sub c}(100)Ge related to Ge orientations was obtained using the measured bandgap of HfO{sub 2} on each orientation and with the Ge bandgap of 0.67 eV. These band offset parameters for carrier confinement would offer an important guidance to design Ge-based p- and n-channel metal-oxide field-effect transistor for low-power application.

  6. Hubble space telescope and ground-based observations of the type Iax supernovae SN 2005hk and SN 2008A

    SciTech Connect (OSTI)

    McCully, Curtis; Jha, Saurabh W. [Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Foley, Ryan J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Chornock, Ryan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Holtzman, Jon A. [Department of Astronomy, MSC 4500, New Mexico State University, P.O. Box 30001, Las Cruces, NM 88003 (United States); Balam, David D. [Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Branch, David [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Filippenko, Alexei V.; Ganeshalingam, Mohan; Li, Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Frieman, Joshua [Kavli Institute for Cosmological Physics and Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Fynbo, Johan; Leloudas, Giorgos [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Galbany, Lluis [Institut de Física d'Altes Energies, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Barcelona) (Spain); Garnavich, Peter M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Graham, Melissa L. [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Hsiao, Eric Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Leonard, Douglas C., E-mail: cmccully@physics.rutgers.edu [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); and others

    2014-05-10T23:59:59.000Z

    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n{sub e} ? 10{sup 9} cm{sup –3}. Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected 'infrared catastrophe', a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a 'complete deflagration' that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.

  7. Calculations of optical properties of the tetraphenyl-X family of isomorphous crystals (X ~ C, Si, Ge, Sn, Pb){

    E-Print Network [OSTI]

    Kaminsky, Werner

    Paper Calculations of optical properties of the tetraphenyl-X family of isomorphous crystals (X ~ C to determine how small structural changes become manifest in the optical properties of crystals we used classical dipole­dipole interaction calculations to estimate the linear birefringence and optical rotatory

  8. Aluminum-stabilized Nb[sub 3]Sn superconductor

    DOE Patents [OSTI]

    Scanlan, R.M.

    1988-05-10T23:59:59.000Z

    Disclosed are an aluminum-stabilized Nb[sub 3]Sn superconductor and process for producing same, utilizing ultrapure aluminum. Ductile components are co-drawn with aluminum to produce a conductor suitable for winding magnets. After winding, the conductor is heated to convert it to the brittle Nb[sub 3]Sn superconductor phase, using a temperature high enough to perform the transformation but still below the melting point of the aluminum. This results in reaction of substantially all of the niobium, while providing stabilization and react-in-place features which are beneficial in the fabrication of magnets utilizing superconducting materials. 4 figs.

  9. Aluminum-stabilized Nb/sub 3/Sn superconductor

    DOE Patents [OSTI]

    Scanlan, R.M.

    1984-02-10T23:59:59.000Z

    This patent discloses an aluminum-stabilized Nb/sub 3/Sn superconductor and process for producing same, utilizing ultrapure aluminum. Ductile components are co-drawn with aluminum to produce a conductor suitable for winding magnets. After winding, the conductor is heated to convert it to the brittle Nb/sub 3/Sn superconductor phase, using a temperature high enough to perform the transformation but still below the melting point of the aluminum. This results in reaction of substantially all of the niobium, while providing stabilization and react-in-place features which are beneficial in the fabrication of magnets utilizing superconducting materials.

  10. Quench margin measurement in Nb3Sn quadrupole magnet

    SciTech Connect (OSTI)

    Kashikhin, V.V.; Bossert, R.; Chlachidze, G.; Lamm, M.; Novitski, I.; Zlobin, A.V.; /Fermilab

    2008-08-01T23:59:59.000Z

    One of the possible practical applications of the Nb{sub 3}Sn accelerator magnets is the LHC luminosity upgrade that involves replacing the present NbTi focusing quadrupoles in two high-luminosity interaction regions (IR). The IR magnets are exposed to strong radiation from the interaction point that requires a detailed investigation of the magnet operating margins under the expected radiation-induced heat depositions. This paper presents the results of simulation and measurement of quench limits and temperature margins for a Nb{sub 3}Sn model magnet using a special midplane strip heater.

  11. A Second UV "Light Bulb" behind the SN 1006 Remnant

    E-Print Network [OSTI]

    Winkler, P F; Long, Knox S.

    1997-01-01T23:59:59.000Z

    A point X-ray source located 9 arcmin northeast of the center of SN~1006 has been spectroscopically identified as a background QSO, with a redshift of 0.335. The object is moderately bright, with magnitude V=18.3. If its ultraviolet spectrum is typical of low-z quasars, this object will be a second (after the Schweizer-Middleditch star) source to use for absorption spectroscopy of material within SN 1006. Absorption spectra provide a unique probe for unshocked ejecta within this supernova remnant, and can possibly solve the long-standing problem of "missing" iron in the remnants of Type Ia supernovae.

  12. A Second UV "Light Bulb" behind the SN 1006 Remnant

    E-Print Network [OSTI]

    P. Frank Winkler; Knox S. Long

    1997-07-22T23:59:59.000Z

    A point X-ray source located 9 arcmin northeast of the center of SN~1006 has been spectroscopically identified as a background QSO, with a redshift of 0.335. The object is moderately bright, with magnitude V=18.3. If its ultraviolet spectrum is typical of low-z quasars, this object will be a second (after the Schweizer-Middleditch star) source to use for absorption spectroscopy of material within SN 1006. Absorption spectra provide a unique probe for unshocked ejecta within this supernova remnant, and can possibly solve the long-standing problem of "missing" iron in the remnants of Type Ia supernovae.

  13. Pb-free Sn-Ag-Cu ternary eutectic solder

    DOE Patents [OSTI]

    Anderson, I.E.; Yost, F.G.; Smith, J.F.; Miller, C.M.; Terpstra, R.L.

    1996-06-18T23:59:59.000Z

    A Pb-free solder includes a ternary eutectic composition consisting essentially of about 93.6 weight % Sn-about 4.7 weight % Ag-about 1.7 weight % Cu having a eutectic melting temperature of about 217 C and variants of the ternary composition wherein the relative concentrations of Sn, Ag, and Cu deviate from the ternary eutectic composition to provide a controlled melting temperature range (liquid-solid ``mushy`` zone) relative to the eutectic melting temperature (e.g. up to 15 C above the eutectic melting temperature). 5 figs.

  14. Hydrothermal synthesis and infrared emissivity property of flower-like SnO{sub 2} particles

    SciTech Connect (OSTI)

    Tian, J. X. [Institute of Photonics and Photon-Technology, Northwest University, Xi'an 710069 (China) [Institute of Photonics and Photon-Technology, Northwest University, Xi'an 710069 (China); Beijing Institute of Environmental Features, Beijing, 100854 (China); Zhang, Z. Y., E-mail: zhangzy@nwu.edu.cn [Institute of Photonics and Photon-Technology, Northwest University, Xi'an 710069 (China); School of Information Science and Technology, Northwest University, Xi'an 710127 (China); Yan, J. F.; Ruan, X. F.; Yun, J. N.; Zhao, W.; Zhai, C. X. [School of Information Science and Technology, Northwest University, Xi'an 710127 (China)] [School of Information Science and Technology, Northwest University, Xi'an 710127 (China)

    2014-04-15T23:59:59.000Z

    The flower-like SnO{sub 2} particles are synthesized through a simple hydrothermal process. The microstructure, morphology and the infrared emissivity property of the as-prepared products are characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), and infrared spectroradio meter (ISM) respectively. The results show that the as-prepared SnO{sub 2} products are all indexed to tetragonal cassiterite phase of SnO{sub 2}. The different molarity ratios of the OH{sup ?} concentration to Sn{sup 4+} concentration ([OH{sup ?}]:[Sn{sup 4+}]) and the polyacrylamide (PAM) lead to the different morphological structures of SnO{sub 2}, which indicates that both the [OH{sup ?}]:[Sn{sup 4+}] and the PAM play an important role in the morphological evolution respectively. The infrared emissivities of the as-prepared SnO{sub 2} products are discussed.

  15. Test Results for HD1, a 16 Tesla Nb3Sn Dipole Magnet

    E-Print Network [OSTI]

    Lietzke, A.F.

    2011-01-01T23:59:59.000Z

    Design and Fabrication ofa 16 Tesla Nb 3 Sn Dipole Magnet",Test Results for HD 1, a 16 Tesla Nb 3 Sn Dipole Magnet A.F.and bore fields above 16 Tesla. II. MAGNET FEATURES AND TEST

  16. Template Synthesis of Tubular Sn-Based Nanostructures for Lithium Ion Storage

    E-Print Network [OSTI]

    Wang, Yong

    We report herewith the preparation of SnO? nanotubes with very good shape and size control, and with and without a carbon nanotube overlayer, The SnO?-core/carbon-shell nanotubes are excellent reversible Li ion storage ...

  17. Fluorine doping in dilute magnetic semiconductor Sn1–xFexO2...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fluorine doping in dilute magnetic semiconductor Sn1–xFexO2. Fluorine doping in dilute magnetic semiconductor Sn1–xFexO2. Abstract: Recent studies have reported...

  18. Alpha Emission Near 100Sn and the Termination of the rp Process

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Alpha Emission Near 100 Sn and the Termination of the rp Process The astrophysical rp-process is thought to reach a termination point in the region of 100 Sn, via the...

  19. Nb3Sn superconducting magnets for electron cyclotron resonance ion sources

    E-Print Network [OSTI]

    Ferracin, P.

    2011-01-01T23:59:59.000Z

    the design of a N b S n superconducting magnet system for aNbjSn superconducting magnets for electron cyclotron5 C H 1 1 2 3 1 . Nb Sn superconducting magnets for electron

  20. GE Appliances: Order (2010-CE-2113)

    Broader source: Energy.gov [DOE]

    DOE issued an Order after entering into a Compromise Agreement with General Electric Appliances after finding GE Appliances had failed to certify that certain models of dehumidifiers comply with the applicable energy conservation standards.

  1. GE's Christine Furstoss Named to NACIE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    companies like GE will need workers with new and advanced skills in areas like 3D printing and virtual design. It's all about growing a new generation of workforce skills,...

  2. Electrochemical Properties of Disordered-Carbon-Coated SnO2 Nanoparticles for Li Rechargeable Batteries

    E-Print Network [OSTI]

    Park, Byungwoo

    Batteries Taeho Moon, Chunjoong Kim, Sun-Tae Hwang, and Byungwoo Park*,z School of Materials Science batteries.1-5 It is rationalized that the reactions of SnO2 with lithium are SnO2 + 4Li Sn + 2Li2O and Sn is to distribute nanoparticles uniformly on a large matrix such as graphite, mesoporous carbon, etc.12,13 However

  3. GE Unveils High-Tech Superhero GENIUS MAN | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    education Committed to inspiring the next generation of scientists and engineers Infused with an array of superpowers inspired by GE technologies Super Vision, ability to...

  4. Microstructure development in Nb3Sn(Ti) internal tin superconducting wire

    E-Print Network [OSTI]

    Elliott, James

    Microstructure development in Nb3Sn(Ti) internal tin superconducting wire I. Pong Æ S. C. Hopkins Æ have studied the phase formation sequences in a Nb3Sn `internal tin' process superconductor. Heat treatments were performed to convert the starting materials of tin, Ti­Sn, copper and niobium, to bronze

  5. Be a part of something bigger than yourself GE Healthcare

    E-Print Network [OSTI]

    Rimon, Elon

    Be a part of something bigger than yourself GE Healthcare Position: Mechanical Engineer as a contractor · Working at GE site at Tirat-Carmel. · Start: immediately · Duration 6-10 months, with optional elongation. ElgemsMoked@ge.com-CV www.gehealthcare.com We are GE Healthcare, a $17 billion division

  6. SN 2008ha: AN EXTREMELY LOW LUMINOSITY AND EXCEPTIONALLY LOW ENERGY SUPERNOVA

    SciTech Connect (OSTI)

    Foley, Ryan J.; Kirshner, Robert P.; Challis, Peter J.; Friedman, Andrew S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chornock, Ryan; Filippenko, Alexei V.; Ganeshalingam, Mohan; Li, Weidong; Cenko, S. Bradley; Modjaz, Maryam; Silverman, Jeffrey M. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Wood-Vasey, W. Michael [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States)], E-mail: rfoley@cfa.harvard.edu

    2009-08-15T23:59:59.000Z

    We present ultraviolet, optical, and near-infrared photometry as well as optical spectra of the peculiar supernova (SN) 2008ha. SN 2008ha had a very low peak luminosity, reaching only M{sub V} = -14.2 mag, and low line velocities of only {approx}2000 km s{sup -1} near maximum brightness, indicating a very small kinetic energy per unit mass of ejecta. Spectroscopically, SN 2008ha is a member of the SN 2002cx-like class of SNe, a peculiar subclass of SNe Ia; however, SN 2008ha is the most extreme member, being significantly fainter and having lower line velocities than the typical member, which is already {approx}2 mag fainter and has line velocities {approx}5000 km s{sup -1} smaller (near maximum brightness) than a normal SN Ia. SN 2008ha had a remarkably short rise time of only {approx}10 days, significantly shorter than either SN 2002cx-like objects ({approx}15 days) or normal SNe Ia ({approx}19.5 days). The bolometric light curve of SN 2008ha indicates that SN 2008ha peaked at L {sub peak} = (9.5 {+-} 1.4) x 10{sup 40} erg s{sup -1}, making SN 2008ha perhaps the least luminous SN ever observed. From its peak luminosity and rise time, we infer that SN 2008ha generated (3.0 {+-} 0.9) x 10{sup -3} M {sub sun} of {sup 56}Ni, had a kinetic energy of {approx}2 x 10{sup 48} erg, and ejected 0.15 M {sub sun} of material. The host galaxy of SN 2008ha has a luminosity, star formation rate, and metallicity similar to those of the Large magellanic Cloud. We classify three new (and one potential) members of the SN 2002cx-like class, expanding the sample to 14 (and one potential) members. The host-galaxy morphology distribution of the class is consistent with that of SNe Ia, Ib, Ic, and II. Several models for generating low-luminosity SNe can explain the observations of SN 2008ha; however, if a single model is to describe all SN 2002cx-like objects, deflagration of carbon-oxygen white dwarfs, with SN 2008ha being a partial deflagration and not unbinding the progenitor star, is preferred. The rate of SN 2008ha-like events is {approx}10% of the SN Ia rate, and in the upcoming era of transient surveys, several thousand similar objects may be discovered, suggesting that SN 2008ha may be the tip of a low-luminosity transient iceberg.

  7. LEED structure determination of the 3R30-Sn surface

    E-Print Network [OSTI]

    Soares, Edmar Avellar

    diffraction (LEED); Surface structure, morphology, roughness, and topography; Surface relaxationLEED structure determination of the Ni(111)ð p 3 Â p 3ÞR30°-Sn surface E.A. Soares a , C surface phase. The results confirm that the surface layer comprises a substitutional alloy of composition

  8. Analysis of Neutrino Signals from SN1987A

    E-Print Network [OSTI]

    G. Pagliaroli; M. L. Costantini; F. Vissani

    2008-04-29T23:59:59.000Z

    We study SN1987A neutrino events through a likelihood analysis with one-component (cooling) and two-component (accretion and cooling) emission model. We show that there is a 3.2 sigma hint for the initial accretion phase.

  9. Evolution of the pygmy dipole resonance in Sn isotopes

    E-Print Network [OSTI]

    H. K. Toft; A. C. Larsen; A. Bürger; M. Guttormsen; A. Görgen; H. T. Nyhus; T. Renstrøm; S. Siem; G. M. Tveten; A. Voinov

    2011-05-18T23:59:59.000Z

    Nuclear level density and $\\gamma$-ray strength functions of $^{121,122}$Sn below the neutron separation energy are extracted with the Oslo method using the ($^3$He,$^3$He$^\\prime\\gamma$) and ($^3$He,$\\alpha \\gamma$) reactions. The level densities of $^{121,122}$Sn display step-like structures, interpreted as signatures of neutron pair breaking. An enhancement in both strength functions, compared to standard models for radiative strength, is observed in our measurements for $E_\\gamma \\gtrsim 5.2 $ MeV. This enhancement is compatible with pygmy resonances centered at $\\approx 8.4(1)$ and $\\approx 8.6(2)$ MeV, respectively, and with integrated strengths corresponding to $\\approx1.8^{+1}_{-5}%$ of the classical Thomas-Reiche-Kuhn sum rule. Similar resonances were also seen in $^{116-119}$Sn. Experimental neutron-capture cross reactions are well reproduced by our pygmy resonance predictions, while standard strength models are less successful. The evolution as a function of neutron number of the pygmy resonance in $^{116-122}$Sn is described as a clear increase of centroid energy from 8.0(1) to 8.6(2) MeV, but with no observable difference in integrated strengths.

  10. Mg2SnO4 ceramics I. Synthesisprocessingmicrostructure correlation

    E-Print Network [OSTI]

    Azad, Abdul-Majeed

    , no reliable technical information on the electrical behavior of the compounds in the pseudobinary MgO±SnO2, such as, thermally stable capacitors with low permittiv- ity and small loss tangent [1±6]. Interestingly, such as, synthesis, processing, microstructure and electrical behavior of these materials; such a corre

  11. UC IRVINE GENERAL EDUCATION (GE) REQUIREMENT AND APPROVED GE COURSES, 201213 Includes course titles and Schedule of Classes designations

    E-Print Network [OSTI]

    Loudon, Catherine

    UC IRVINE GENERAL EDUCATION (GE) REQUIREMENT AND APPROVED GE COURSES, 2012­13 Includes course titles and Schedule of Classes designations GENERAL EDUCATION (GE) REQUIREMENT UCI is committed undergraduates complete a set of general education (GE) requirements. General education courses introduce

  12. 2009-10 Princeton Global Scholar Ge Zhaoguang. Professor Ge is the founding director of the National Institute for Advanced

    E-Print Network [OSTI]

    2009-10 Princeton Global Scholar Ge Zhaoguang. Professor Ge is the founding director, and emendation of all sorts of newly discovered texts (mostly found at archaeological sites). Professor Ge University, Professor Ge taught at Tsinghua University for a number of years. He is known for many important

  13. Measurement of the direct energy gap of coherently strained SnxGe1x Ge,,001... heterostructures

    E-Print Network [OSTI]

    Atwater, Harry

    Measurement of the direct energy gap of coherently strained SnxGe1Àx ÕGe,,001... heterostructures The direct energy gap has been measured for coherently strained SnxGe1 x alloys on Ge 001 substrates with 0 for coherently strained SnxGe1 x alloys indicates a large alloy contribution and a small strain contribution

  14. GE Advising & Registration Students FT Faculty PT Faculty Admin Unit 4 Other Staff Students have access to quality GE advising

    E-Print Network [OSTI]

    de Lijser, Peter

    GE Advising & Registration Students FT Faculty PT Faculty Admin Unit 4 Other Staff Students have access to quality GE advising 9% 13% 11% 13% 10% 8% Faculty can easily advise students on GE requirements 10% 18% 9% 24% 33% 11% Staff academic advisors can easily advise students on GE requirements 8% 11

  15. High-germanium-content SiGe islands formed on compliant oxide by SiGe Haizhou Yina)

    E-Print Network [OSTI]

    High-germanium-content SiGe islands formed on compliant oxide by SiGe oxidation Haizhou Yina and the nonuniformity of the enhanced germanium content during the SiGe oxidation were improved by depositing a silicon was relaxed by lateral expansion of the SiGe islands, showing that dislocations were not required

  16. Relaxation and recombination processes in Ge/SiGe multiple quantum wells

    SciTech Connect (OSTI)

    Gatti, E., E-mail: gatti@mater.unimib.it; Giorgioni, A., E-mail: gatti@mater.unimib.it; Grilli, E., E-mail: gatti@mater.unimib.it; Guzzi, M., E-mail: gatti@mater.unimib.it [L-NESS and Università di Milano-Bicocca, Dip. di Scienza dei Materiali, via Cozzi 53, 20125 Milano (Italy); Chrastina, D.; Isella, G. [L-NESS and Politecnico di Milano, Dip. di Fisica, via Anzani 42, 22100 Como (Italy); Chernikov, A.; Kolata, K.; Bornwasser, V.; Köster, N. S.; Woscholski, R.; Chatterjee, S. [Faculty of Physics and Materials Sciences Center, Philipps-Universität, Renthof 5, 35032 Marburg (Germany)

    2013-12-04T23:59:59.000Z

    The carrier dynamics that occurs in Ge/SiGe QWs when electrons are excited to confined states at ? is studied by means of optical spectroscopy at different lattice temperatures. The typical times for the different relaxation and recombination processes are given and discussed.

  17. The XRF080109-SN2008D and a decade of GRB-Jet-SN connection

    E-Print Network [OSTI]

    Fargion, D; Oliva, P; Manniti, F

    2009-01-01T23:59:59.000Z

    Last and nearest GRB-XRF 080109 has been an exceptional lesson on GRB nature. After a decade (since 25 April 08) we know that Supernovae may often contain a Jet. Its persistent activity may shine on axis as a GRBs. Such a persistent, thin beamed gamma jet may be powered by either a BH (Black Holes) or Pulsars. Late stages of these jets may loose the SN traces and appear as a short GRB or a long orphan GRB (depending on jet angular velocity and view angle). XRF are peripherical viewing of the jets. These precessing and spinning gamma jet are originated by Inverse Compton and-or Synchrotron Radiation at pulsars or micro-quasars sources, by ultra-relativistic electrons. These Jets are most powerful at Supernova birth, blazing, once on axis, to us and flashing GRB detector. The trembling of the thin jet explains naturally the observed erratic multi-explosive structure of different GRBs. The jets are precessing (by binary companion or inner disk asymmetry) and decaying by power on time scales of few hours, but the...

  18. In Search of Cyclohexane-like Sn6 12-: Synthesis of Li2Ln5Sn7 (Ln ) Ce,

    E-Print Network [OSTI]

    such as the alkali, alkaline-earth, and rare-earth elements with less electropos- itive metals or semimetals state for the rare-earth cations and, therefore, 17 available electrons from the cations per formula), alkaline-earth (Ae) or lanthanide metal (Ln), and Sn.2 Most of the structures in this system are directly

  19. Deviations from ideal nucleation-limited relaxation in high-Ge content compositionally graded SiGe/Si*

    E-Print Network [OSTI]

    Deviations from ideal nucleation-limited relaxation in high-Ge content compositionally graded SiGe the sudden rise in threading dislocation density in Ge-rich relaxed graded SiGe layers grown at higher growth systems, including relaxed graded SiGe on Si substrates i.e., x Si1-xGex /Si ,1,2 InGaP on GaP substrates

  20. Preparation of Ni-Sn alloys by an electroless-deposition method

    SciTech Connect (OSTI)

    Shimauchi, Hidenori; Ozawa, Susumu; Tamura, Keiu; Osaka, Tetsuya (Waseda Univ., Tokyo (Japan). Dept. of Applied Chemistry)

    1994-06-01T23:59:59.000Z

    Ni-Sn alloy is expected for as a functional material, because of its excellent corrosion resistance, wear resistance, and solderability. Electroless-deposited Ni-Sn alloy films were investigated to increase tin content in the deposit. The maximum tin contents of electroless Ni-Sn-P and Ni-Sn-B were ca. 30 atom percent (a/o) and 42 a/o, respectively. The maximum tin contents in the case of Ni-Sn-B was nearly equal to that of electrodeposited Ni-Sn alloy already reported. The crystallinity of Ni-Sn-P and Ni-Sn-B alloys was raised up with an increase in tin content. The corrosion resistance of Ni-Sn-P and Ni-Sn-B alloys was between that of amorphous and crystalline electroless-deposited Ni-P. Codeposition of tin into Ni-P films improved solderability, but into the Ni-B films, the solderability of Ni-Sn-B films situated in the region between those of Ni-P and NiB, because the solderability of NiB is higher.

  1. Structure and properties of YbZnSn, YbAgSn, and Yb{sub 2}Pt{sub 2}Pb

    SciTech Connect (OSTI)

    Poettgen, R.; Arpe, P.E.; Kussmann, D.; Kuennen, B.; Kotzyba, G.; Muellmann, R.; Mosel, B.D. [Univ. Muenster (Germany)] [Univ. Muenster (Germany); Felser, C. [Johannes Gutenberg Univ., Mainz (Germany). Inst. fuer Anorganische Chemie] [Johannes Gutenberg Univ., Mainz (Germany). Inst. fuer Anorganische Chemie

    1999-07-01T23:59:59.000Z

    YbZnSn, YbAgSn, and Yb{sub 2}Pt{sub 2}Pb were synthesized by reacting the elements in sealed tantalum tubes in a high-frequency furnace. The structures of YbAgSn and Yb{sub 2}Pt{sub 2}Pb were refined from single crystal X-ray data: YbAgPb type, P{bar 6}m2, a = 479.2(2) pm, c = 1087.3(3) pm, wR2 = 0.050, BASF = 0.34(8), 509 F{sup 2} values, 18 variables for Yb{sub 2}Pt{sub 2}Pb. The lattice constants of YbZnSn are confirmed: NdPtSb type, P6{sub 3}mc, a = 464.7(1) pm, c = 747.7(2) pm. The stannides YbZnSn and YbAgSn crystallize with superstructures of the AlB{sub 2} type. The zinc (silver) and tin atoms form ordered Zn{sub 3}Sn{sub 3} and Ag{sub 3}Sn{sub 3} hexagons, respectively. Magnetic susceptibility measurements on YbZnSn and YbAgSn show Pauli paramagnetism with room temperature susceptibilities of 2.5(1) {times} 10{sup {minus}9} and 4.6(1) {times} 10{sup {minus}9} m{sup 3}/mol. Electrical resistivity measurements indicate metallic conductivity with specific resistivities of 440 {+-} 40 {mu}{Omega}cm (YbZnSn) and 490 {+-} 40 {mu}{Omega}cm (YbAgSn) at 300 K. {sup 119}Sn Moessbauer spectra of YbZnSn show a single signal at room temperature with an isomer shift of {delta} = 1.85(1) mm/s. YbAgSn shows two superimposed signals at 78 K: a singlet at {delta} = 1.94(1) mm/s and a second signal at {delta} = 1.99(1) mm/s subjected to quadrupole splitting of {Delta}E{sub Q} = 1.35(1) mm/s, in agreement with the two crystallographically different tin sites.

  2. Ge/SiGe quantum wells on Si(111): Growth, structural, and optical properties

    SciTech Connect (OSTI)

    Gatti, E., E-mail: eleonora.gatti@mater.unimib.it; Pezzoli, F.; Grilli, E. [L-NESS and Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via Cozzi 55, I-20125 Milano (Italy); Isa, F.; Chrastina, D.; Isella, G. [L-NESS and Dipartimento di Fisica, Politecnico di Milano, Polo di Como, via Anzani 42, I - 22100 Como (Italy); Müller Gubler, E. [Electron Microscopy Center of ETH Zürich (EMEZ), August-Piccard-Hof 1, CH-8093 Zürich (Switzerland)

    2014-07-28T23:59:59.000Z

    The epitaxial growth of Ge/Si{sub 0.15}Ge{sub 0.85} multiple quantum wells (MQWs) on Si(111) substrates is demonstrated. A 3??m thick reverse, double-step virtual substrate with a final composition of Si{sub 0.10}Ge{sub 0.90} has been employed. High resolution XRD, TEM, AFM and defect etching analysis has been used for the study of the structural properties of the buffer and of the QWs. The QW stack is characterized by a threading dislocation density of about 3?×?10{sup 7?}cm{sup ?2} and an interdiffusion layer at the well/barrier interface of 2.1?nm. The quantum confined energy levels of this system have been calculated using the k·p and effective mass approximation methods. The Ge/Si{sub 0.15}Ge{sub 0.85} MQWs have been characterized through absorption and photoluminescence measurements. The optical spectra have been compared with those of Ge/Si{sub 0.15}Ge{sub 0.85} QWs grown on Si(001) through a thick graded virtual substrate.

  3. Optical Link on Silicon Employing Ge/SiGe Quantum Well Structures Onur Fidaner, Ali K. Okyay, Jonathan E. Roth, Rebecca K. Scheavitz, Yu-Hsuan Kuo*

    E-Print Network [OSTI]

    Miller, David A. B.

    Optical Link on Silicon Employing Ge/SiGe Quantum Well Structures Onur Fidaner, Ali K. Okyay University, Taipei, Taiwan Abstract: We demonstrate an optical link on silicon employing Ge/SiGe quantum well of the quantum-confined Stark effect (QCSE) on silicon using Ge/SiGe quantum wells opened up the possibility

  4. The thermoelectric properties of Ge/SiGe modulation doped superlattices A. Samarelli, L. Ferre Llin, S. Cecchi, J. Frigerio, T. Etzelstorfer et al.

    E-Print Network [OSTI]

    Hague, Jim

    The thermoelectric properties of Ge/SiGe modulation doped superlattices A. Samarelli, L. Ferre Llin thermoelectric properties of Ge/SiGe modulation doped superlattices A. Samarelli,1 L. Ferre Llin,1 S. Cecchi,2 J in the thermoelectric figure of merit, ZT, and power factor at room temperature over bulk Ge, Si1ÀyGey, and Si/Ge

  5. Dipole polarizability of 120Sn and nuclear energy density functionals

    E-Print Network [OSTI]

    Hashimoto, T; Reinhard, P -G; Tamii, A; von Neumann-Cosel, P; Adachi, T; Aoi, N; Bertulani, C A; Fujita, H; Fujita, Y; Ganio?lu, E; Hatanaka, K; Iwamoto, C; Kawabata, T; Khai, N T; Krugmann, A; Martin, D; Matsubara, H; Miki, K; Neveling, R; Okamura, H; Ong, H J; Poltoratska, I; Ponomarev, V Yu; Richter, A; Sakaguchi, H; Shimbara, Y; Shimizu, Y; Simonis, J; Smit, F D; Süsoy, G; Thies, J H; Suzuki, T; Yosoi, M; Zenihiro, J

    2015-01-01T23:59:59.000Z

    The electric dipole strength distribution in 120Sn between 5 and 22 MeV has been determined at RCNP Osaka from a polarization transfer analysis of proton inelastic scattering at E_0 = 295 MeV and forward angles including 0{\\deg}. Combined with photoabsorption data an electric dipole polarizability alpha_D(120Sn) = 8.93(36) fm^3 is extracted. The correlation of this value with alpha_D for 208Pb serves as a test of energy density functionals (EDFs). The majority of models based on Skyrme interactions can describe the data while relativistic approaches fail. The accuracy of the experimental results provides important constraints on the static isovector properties of EDFs used to predict symmetry energy parameters and the neutron skin thickness of nuclei.

  6. Optical properties of SnO{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Koshy, Jiji, E-mail: drkcgeorge@gmail.com; Chandran, Anoop, E-mail: drkcgeorge@gmail.com; Samuel, Soosen, E-mail: drkcgeorge@gmail.com; George, K. C., E-mail: drkcgeorge@gmail.com [Department of Physics S.B.College Changanassery, Kerala, 686101 (India)

    2014-10-15T23:59:59.000Z

    SnO{sub 2} nanoparticles were successfully prepared by a sol-gel technique. The samples were analyzed by XRD, SEM, TEM, UV, Photoluminescence (PL) and Raman studies. The obtained product has a particle size of 12 nm with absorption peak at 278 nm. The absorption peak shows a blue shift when compared to the bulk due to quantum confinement. The FTIR spectrum of the prepared SnO{sub 2} nanoparticles exhibits a broad absorption band between 3100 and 3400 cm{sup ?1} as well as a narrower peak at 1600 cm{sup ?1}. The PL spectrum shows two strong peaks at 420 and 484 nm and broad peak between 430 and 470 nm.

  7. Strain tolerances in Nb/sub 3/Sn conductors

    SciTech Connect (OSTI)

    Luhman, T.

    1982-01-01T23:59:59.000Z

    This paper reviews the literature pertinent to the effect of strain on the critical currents of a variety of differently heat-treated multifilamentary Nb/sub 3/Sn superconductors. The dependence of the critical currents on the parameters of uniaxial, tensile, bending, and intrinsic strains, and on temperature and composite ratio variations, is both plotted and analyzed. A review of specific efforts to enhance the strain tolerances of Nb/sub 3/Sn superconductors is given. Those efforts include 1) the approach of minimizing an accomodating plastic flow in the bronze during a cooldown from the reaction heat treatment temperaure by alloying the bronze with Be; 2) the method of jacketing a conductor with stainless steel to enhance the effect R /SUB v/ ; and 3) the ''wind and react'' approach, or the procedure olf vacuum-impregnating the coil windings with epoxy following the reaction heat treatment.

  8. Nb3Sn Quadrupole Magnets for the LHC IR

    SciTech Connect (OSTI)

    Sabbi, G.; Caspi, S.; Chiesa, L.; Coccoli, M.; Dietderich, D.r.; Ferracin, P.; Gourlay, S.A.; Hafalia, R.R.; Lietzke, A.F.; McInturff, A.D.; Scanlan, R.M.

    2001-08-01T23:59:59.000Z

    The development of insertion quadrupoles with 205 T/m gradient and 90 mm bore represents a promising strategy to achieve the ultimate luminosity goal of 2.5 x 10{sup 34} cm{sup -2}s{sup -1} at the Large Hadron Collider (LHC). At present, Nb{sub 3}Sn is the only practical conductor which can meet these requirements. Since Nb{sub 3}Sn is brittle, and considerably more strain sensitive than NbTi, the design concepts and fabrication techniques developed for NbTi magnets need to be modified appropriately. In addition, IR magnets must provide high field quality and operate reliably under severe radiation loads. The results of conceptual design studies addressing these issues are presented.

  9. Development of a large aperture Nb3Sn racetrack quadrupolemagnet

    SciTech Connect (OSTI)

    Ferracin, Paolo; Bartlett, Scott E.; Caspi, Shlomo; Dietderich,Daniel R.; Gourlay, Steven A.; Hannaford, Charles R.; Hafalia, AurelioR.; Lietzke, Alan F.; Mattafirri, Sara; McInturff, Alfred D.; Nyman,Mark; Sabbi, Gianluca

    2005-04-14T23:59:59.000Z

    The U.S. LHC Accelerator Research Program (LARP), a collaboration between BNL, FNAL, LBNL, and SLAC, has among its major objectives the development of advanced magnet technology for an LHC luminosity upgrade. The LBNL Superconducting Magnet Group supports this program with a broad effort involving design studies, Nb{sub 3}Sn conductor development, mechanical models, and basic prototypes. This paper describes the development of a large aperture Nb{sub 3}Sn racetrack quadrupole magnet using four racetrack coils from the LBNL Subscale Magnet (SM) Program. The magnet provides a gradient of 95 T/m in a 110 mm bore, with a peak field in the conductor of 11.2 T. The coils are prestressed by a mechanical structure based on a pre-tensioned aluminum shell, and axially supported with aluminum rods. The mechanical behavior has been monitored with strain gauges and the magnetic field has been measured. Results of the test are reported and analyzed.

  10. Low-energy electric dipole response in 120Sn

    E-Print Network [OSTI]

    A. M. Krumbholz; P. von Neumann-Cosel; T. Hashimoto; A. Tamii; T. Adachi; C. A. Bertulani; H. Fujita; Y. Fujita; E. Ganioglu; K. Hatanaka; C. Iwamoto; T. Kawabata; N. T. Khai; A. Krugmann; D. Martin; H. Matsubara; R. Neveling; H. Okamura; H. J. Ong; I. Poltoratska; V. Yu. Ponomarev; A. Richter; H. Sakaguchi; Y. Shimbara; Y. Shimizu; J. Simonis; F. D. Smit; G. Susoy; J. H. Thies; T. Suzuki; M. Yosoi; J. Zenihiro

    2015-03-04T23:59:59.000Z

    The electric dipole strength in 120Sn has been extracted from proton inelastic scattering experiments at E_p = 295 MeV and at forward angles including 0 degree. Below neutron threshoild it differs from the results of a 120Sn(gamma,gamma') experiment and peaks at an excitation energy of 8.3 MeV. The total strength corresponds to 2.3(2)% of the energy-weighted sum rule and is more than three times larger than what is observed with the (gamma,gamma') reaction. This implies a strong fragmentation of the E1 strength and/or small ground state branching ratios of the excited 1- states.

  11. 23 6 12 8:00 III-V/Ge CMOS

    E-Print Network [OSTI]

    Katsumoto, Shingo

    23 6 12 8:00 - 1 - 1. : III-V/Ge CMOS ~ 200%~ 2. : III-V (Ge) III-V/Ge CMOS (Si) 200% III-V/Ge CMOS 200% III-V/Ge CMOS () () () () III-V III-V/Ge CMOS (1) III-V Ge III-V/Ge CMOS (2) III-V-OI MOSFET (3) III-V/Ge CMOS "2011 Symposia on VLSI

  12. Novel approaches to low temperature transient liquid phase bonding in the In-Sn/Cu and In-Sn-Bi/Cu systems

    E-Print Network [OSTI]

    Fischer, David S., Ph. D. Massachusetts Institute of Technology

    2008-01-01T23:59:59.000Z

    A fluxless low temperature transient liquid phase (LTTLP) bonding process was studied as a method of producing Cu/Cu joints below 125°C and 75°C using interlayer alloys from the In-Sn and In-Sn-Bi systems. Using thermodynamic ...

  13. Measurement of the neutron-capture cross section of ??Ge and ??Ge below 15 MeV and its relevance to 0??? decay searches of ??Ge

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bhike, Megha; Fallin, B.; Tornow, W.

    2015-02-01T23:59:59.000Z

    The neutron radiative-capture cross section of ??Ge was measured between 0.4 and 14.8 MeV using the activation technique. Germanium samples with the isotopic abundance of ~86% ??Ge and ~14% ??Ge used in the 0??? searches by the GERDA and Majorana Collaborations were irradiated with monoenergetic neutrons produced at eleven energies via the ³H(p,n)³He, ²H(d,n)³He and ³H(d,n)?He reactions. Previously, data existed only at thermal energies and at 14 MeV. As a by-product, capture cross-section data were also obtained for ??Ge at neutron energies below 8 MeV. Indium and gold foils were irradiated simultaneously for neutron fluence determination. High-resolution ?-ray spectroscopy wasmore »used to determine the ?-ray activity of the daughter nuclei of interest. For the ??Ge total capture cross section the present data are in good agreement with the TENDL-2013 model calculations and the ENDF/B-VII.1 evaluations, while for the ??Ge(n,?)??Ge reaction, the present data are about a factor of two larger than predicted. It was found that the ??Ge(n,?)??Ge yield in the High-Purity Germanium (HPGe) detectors used by the GERDA and Majorana Collaborations is only about a factor of two smaller than the ??Ge(n,?)??Ge yield due to the larger cross section of the former reaction.« less

  14. Gamma-ray lines from SN2014J

    E-Print Network [OSTI]

    Siegert, Thomas

    2015-01-01T23:59:59.000Z

    On 21 January 2014, SN2014J was discovered in M82 and found to be the closest type Ia supernova (SN Ia) in the last four decades. INTEGRAL observed SN2014J from the end of January until late June for a total exposure time of about 7 Ms. SNe Ia light curves are understood to be powered by the radioactive decay of iron peak elements of which $^{56}$Ni is dominantly synthesized during the thermonuclear disruption of a CO white dwarf (WD). The measurement of $\\gamma$-ray lines from the decay chain $^{56}$Ni$\\rightarrow$$^{56}$Co$\\rightarrow$$^{56}$Fe provides unique information about the explosion in supernovae. Canonical models assume $^{56}$Ni buried deeply in the supernova cloud, absorbing most of the early $\\gamma$-rays, and only the consecutive decay of $^{56}$Co should become directly observable through the overlaying material several weeks after the explosion when the supernova envelope dilutes as it expands. Surprisingly, with the spectrometer on INTEGRAL, SPI, we detected $^{56}$Ni $\\gamma$-ray lines at ...

  15. Performance of Nb3Sn Quadrupole Under High Stress

    SciTech Connect (OSTI)

    Felice, H.; Bajko, M.; Bingham, B.; Bordini, B.; Bottura, L.; Caspi, S.; Rijk, G. De; Dietderich, D.; Ferracin, P.; Giloux, C.; Godeke, A.; Hafalia, R.; Milanese, A.; Rossi, L.; Sabbi, G. L.

    2010-08-01T23:59:59.000Z

    Future upgrades of the Large Hadron Collider (LHC) will require large aperture and high gradient quadrupoles. Nb{sub 3}Sn is the most viable option for this application but is also known for its strain sensitivity. In high field magnets, with magnetic fields above 12 T, the Lorentz forces will generate mechanical stresses that may exceed 200 MPa in the windings. The existing measurements of critical current versus strain of Nb{sub 3}Sn strands or cables are not easily applicable to magnets. In order to investigate the impact of high mechanical stress on the quench performance, a series of tests was carried out within a LBNL/CERN collaboration using the magnet TQS03 (a LHC Accelerator Research Program (LARP) 1-meter long, 90-mm aperture Nb{sub 3}Sn quadrupole). The magnet was tested four times at CERN under various pre-stress conditions. The average mechanical compressive azimuthal pre-stress on the coil at 4.2 K ranged from 120 MPa to 200 MPa. This paper reports on the magnet performance during the four tests focusing on the relation between pre-stress conditions and the training plateau.

  16. Imaging the Expanding Shell of SN 2011dh

    E-Print Network [OSTI]

    de Witt, A; Kamble, A; Soderberg, A M; Brunthaler, A; Zauderer, B; Bartel, N; Rupen, M P

    2015-01-01T23:59:59.000Z

    We report on third epoch VLBI observations of the radio-bright supernova SN 2011dh located in the nearby galaxy (7.8 Mpc) M51. The observations took place at $t=453$ d after the explosion and at a frequency of 8.4 GHz. We obtained a fairly well resolved image of the shell of SN 2011dh, making it one of only six recent supernovae for which resolved images of the ejecta are available. By fitting a spherical shell model directly to the visibility measurements we determine the angular radius of SN 2011dh's radio emission to be $636 \\pm 29$ $\\mu$as . At a distance of 7.8 Mpc, this angular radius corresponds to a linear radius of $(7.4 \\pm 0.3) \\times 10^{16}$ cm and an average expansion velocity since the explosion of $18900^{+2800}_{-2400}$ kms$^{-1}$. We also calculated more precise radius measurements for the earlier VLBI observations and we show that all the measured values of the radius of the emission region, up to $t=453$ d, are still almost perfectly consistent with those derived from fitting synchrotron s...

  17. GE Lighting Solutions: Order (2013-SE-4901)

    Broader source: Energy.gov [DOE]

    DOE ordered General Electric Lighting Solutions, LLC to pay a $5,360 civil penalty after finding GE Lighting Solutions had manufactured and distributed in commerce in the U.S. 30 units of basic model DR4-RTFB-23B and 177 units (of which 85 units remain in inventory) of basic model DR4-RTFB-77A-002, noncompliant traffic signal modules.

  18. Viscosity Measurement G.E. Leblanc

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    30 Viscosity Measurement G.E. Leblanc McMaster University R.A. Secco The University of Western Ontario 30.1 Shear Viscosity ............................................................. 30-l Newtonian and Non-Newtonian Fluids l Dimensions and Units of Viscosity l Viscometer Types l Capillary M. Kostic

  19. 140627_GE-map-tech-eng

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032) -Less isN Ground-State Decay Evaluated Dataarge E ddy SN21E I N N O

  20. GE Teams with NY College to Pilot SOFC Technology |GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hudson Valley Community College to Pilot GE Solid Oxide Fuel Cell Technology Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to...

  1. GE partners with 'Girls Who Code' for summer program | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) GE Partners with 'Girls Who Code' for Summer Immersion Program to Help Close the Gender Gap...

  2. GE, NASA Work to Relaunch Supersonic Air Travel | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) GE Supporting NASA's efforts to Relaunch Commercial Supersonic Air Travel Awarded 2- year...

  3. Metastability and relaxation in tensile SiGe on Ge(001) virtual substrates

    SciTech Connect (OSTI)

    Frigerio, Jacopo; Lodari, Mario; Chrastina, Daniel, E-mail: daniel.chrastina@polimi.it; Mondiali, Valeria; Isella, Giovanni [L-NESS, Dipartimento di Fisica, Politecnico di Milano, Polo di Como, via Anzani 42, 22100 Como (Italy); Bollani, Monica [IFN-CNR, L-NESS, via Anzani 42, 22100 Como (Italy)

    2014-09-21T23:59:59.000Z

    We systematically study the heteroepitaxy of SiGe alloys on Ge virtual substrates in order to understand strain relaxation processes and maximize the tensile strain in the SiGe layer. The degree of relaxation is measured by high-resolution x-ray diffraction, and surface morphology is characterized by atomic force microscopy. The results are analyzed in terms of a numerical model, which considers dislocation nucleation, multiplication, thermally activated glide, and strain-dependent blocking. Relaxation is found to be sensitive to growth rate and substrate temperature as well as epilayer misfit and thickness, and growth parameters are found which allow a SiGe film with over 4?GPa of tensile stress to be obtained.

  4. The Majorana Ge-76 double-beta decay project

    SciTech Connect (OSTI)

    Avignone, Frank Titus [ORNL

    2010-01-01T23:59:59.000Z

    The MAJORANA Project is a research and development activity set up to establish the feasibility and cost of a doublebetadecay experiment comprising a one-ton array of Ge detectors fabricated from germanium enriched to about 86% in Ge-76.

  5. GE launches 'STEM empowers OK' initiative in Oklahoma City |...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ok GE Foundation donates 400,000 to enhance STEM education initiatives across Oklahoma STEM Empowers OK to sponsor week-long, GE Summer Science Academy at OSSM for Oklahoma...

  6. Passionate Technologists Wanted at ASME Turbo Expo|GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Meet & Greet GE Researchers at ASME Turbo 2014 Thomas Ripplinger 2014.06.10 Do you love gas turbine research as much as I do? Then I want to meet you next week Since joining GE...

  7. Driving Sensing Technology in Oil & Gas | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    a bit more about Bill's work. Bill joined GE Global Research in 2010. For the past four years his emphasis has been on developing advanced photonics technologies for multiple GE...

  8. Tailoring the spin polarization in Ge/SiGe multiple quantum wells

    SciTech Connect (OSTI)

    Giorgioni, Anna; Pezzoli, Fabio; Gatti, Eleonora; Grilli, Emanuele; Guzzi, Mario [LNESS-Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, I-20125 Milano (Italy); Bottegoni, Federico; Cecchi, Stefano; Ciccacci, Franco; Isella, Giovanni [LNESS-Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano (Italy); Trivedi, Dhara; Song, Yang [Department of Physics and Astronomy, University of Rochester, Rochester (United States); Li, Pengki [Department of Electrical and Computer Engineering, University of Rochester, Rochester (United States); Dery, Hanan [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 and Department of Electrical and Computer Engineering, University of Rochester, Rochester (United States)

    2013-12-04T23:59:59.000Z

    We performed spin-resolved photoluminescence measurements on Ge/SiGe multiple quantum wells with different well thickness and using different exciting power densities. The polarization of the direct emission strongly depends on the relative weight of electrons photoexcited from the light and the heavy hole subbands. The study of the polarization as a function of the exciting power highlights the role of the carrier-carrier interactions in determining spin depolarization.

  9. Strain and stability of ultrathin Ge layers in Si/Ge/Si axial heterojunction nanowires

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ross, Frances M.; Stach, Eric A.; Wen, Cheng -Yen; Reuter, Mark C.; Su, Dong

    2015-03-11T23:59:59.000Z

    The abrupt heterointerfaces in the Si/Ge materials system presents useful possibilities for electronic device engineering because the band structure can be affected by strain induced by the lattice mismatch. In planar layers, heterointerfaces with abrupt composition changes are difficult to realize without introducing misfit dislocations. However, in catalytically grown nanowires, abrupt heterointerfaces can be fabricated by appropriate choice of the catalyst. Here we grow nanowires containing Si/Ge and Si/Ge/Si structures respectively with sub-1nm thick Ge "quantum wells" and we measure the interfacial strain fields using geometric phase analysis. Narrow Ge layers show radial strains of several percent, with a correspondingmore »dilation in the axial direction. Si/Ge interfaces show lattice rotation and curvature of the lattice planes. We conclude that high strains can be achieved, compared to what is possible in planar layers. In addition, we study the stability of these heterostructures under heating and electron beam irradiation. The strain and composition gradients are supposed to the cause of the instability for interdiffusion.« less

  10. Thin SiGe virtual substrates for Ge heterostructures integration on silicon

    SciTech Connect (OSTI)

    Cecchi, S., E-mail: stefano.cecchi@mdm.imm.cnr.it; Chrastina, D.; Frigerio, J.; Isella, G. [L-NESS, Dipartimento di Fisica, Politecnico di Milano–Polo Territoriale di Como, Via Anzani 42, I-22100 Como (Italy); Gatti, E.; Guzzi, M. [L-NESS, Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via Cozzi 53, I-20126 Milano (Italy); Müller Gubler, E. [Electron Microscopy ETH Zurich, ETH Zurich, Auguste-Piccard-Hof 1, CH-8093 Zurich (Switzerland); Paul, D. J. [School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT (United Kingdom)

    2014-03-07T23:59:59.000Z

    The possibility to reduce the thickness of the SiGe virtual substrate, required for the integration of Ge heterostructures on Si, without heavily affecting the crystal quality is becoming fundamental in several applications. In this work, we present 1??m thick Si{sub 1?x}Ge{sub x} buffers (with x?>?0.7) having different designs which could be suitable for applications requiring a thin virtual substrate. The rationale is to reduce the lattice mismatch at the interface with the Si substrate by introducing composition steps and/or partial grading. The relatively low growth temperature (475?°C) makes this approach appealing for complementary metal-oxide-semiconductor integration. For all the investigated designs, a reduction of the threading dislocation density compared to constant composition Si{sub 1?x}Ge{sub x} layers was observed. The best buffer in terms of defects reduction was used as a virtual substrate for the deposition of a Ge/SiGe multiple quantum well structure. Room temperature optical absorption and photoluminescence analysis performed on nominally identical quantum wells grown on both a thick graded virtual substrate and the selected thin buffer demonstrates a comparable optical quality, confirming the effectiveness of the proposed approach.

  11. Similarity of Stranski-Krastanow growth of Ge/Si and SiGe/Si (001)

    SciTech Connect (OSTI)

    Norris, D. J.; Qiu, Y.; Walther, T. [Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Dobbie, A.; Myronov, M. [Department of Physics, University of Warwick, Coventry CV4 7A (United Kingdom)

    2014-01-07T23:59:59.000Z

    This study investigates the onset of islanding (Stranski-Krastanow transition) in strained pure germanium (Ge) and dilute silicon-germanium (SiGe) alloy layers grown by chemical vapour deposition on Si(001) substrates. Integration of compositional profiles is compared to a novel method for quantification of X-ray maps acquired in cross-sectional scanning transmission electron microscopy, together with simulations of surface segregation of Ge. We show that Si{sub 1?x}Ge{sub x} alloys for germanium concentrations x???0.27 grow two-dimensionally and stay flat up to considerable layer thicknesses, while layers with concentrations in the range 0.28?Ge is ±(0.2–0.3) ML. Modelling shows that of the amount of germanium deposited, 0.7 ML segregate towards the free surface so that only ?2.3/x ML are directly incorporated in the layer within a few nanometres, in good agreement with our measurements. For pure Ge (x?=?1), this thickness is smaller than most values quoted in the literature, which we attribute to the high sensitivity of our method to fractional monolayer changes in the effective chemical width of such thin layers.

  12. Bifacial solar cell with SnS absorber by vapor transport deposition

    SciTech Connect (OSTI)

    Wangperawong, Artit [Stanford University, Stanford, California 94305 (United States); Department of Electrical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok 10140 (Thailand); Hsu, Po-Chun; Yee, Yesheng; Herron, Steven M.; Clemens, Bruce M.; Cui, Yi; Bent, Stacey F., E-mail: sbent@stanford.edu [Stanford University, Stanford, California 94305 (United States)

    2014-10-27T23:59:59.000Z

    The SnS absorber layer in solar cell devices was produced by vapor transport deposition (VTD), which is a low-cost manufacturing method for solar modules. The performance of solar cells consisting of Si/Mo/SnS/ZnO/indium tin oxide (ITO) was limited by the SnS layer's surface texture and field-dependent carrier collection. For improved performance, a fluorine doped tin oxide (FTO) substrate was used in place of the Mo to smooth the topography of the VTD SnS and to make bifacial solar cells, which are potentially useful for multijunction applications. A bifacial SnS solar cell consisting of glass/FTO/SnS/CdS/ZnO/ITO demonstrated front- and back-side power conversion efficiencies of 1.2% and 0.2%, respectively.

  13. Monolithic Ge/Si Avalanche Photodiodes Yimin Kanga*

    E-Print Network [OSTI]

    Bowers, John

    Monolithic Ge/Si Avalanche Photodiodes Yimin Kanga* , Mike Morsea , Mario J. Panicciaa , Moshe, Charlottesville, VA 22904, USA Abstract: We demonstrate mesa-type and waveguide-type Ge/Si avalanche photodiodes. Research on the Ge/Si photodiodes, one of the fundamental components needed for building integrated silicon

  14. MOTION OF ELECTRON-HOLE DROPS IN Ge

    E-Print Network [OSTI]

    Westervelt, R.M.

    2011-01-01T23:59:59.000Z

    MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.OF ELECTRON-HOLE DROPS IN Ge R M Westervelt, J C Culbertson

  15. Ge.Meyer -MPL-27.11.002 Status Tunerentwicklung

    E-Print Network [OSTI]

    Ge.Meyer -MPL- 27.11.002 Status Tunerentwicklung 1) Geschichte: Alter franz. Tuner weich, hatte Hysterese. Federkonstante: Gerechnet 5,4 µ/kN, gemessen 26,7 µ/kN (Faktor 5), Ge.Meyer gerechnet 14,6 µ Felder. 2) Tuner 0 / H.Kaiser, Ge.Meyer -MPL- Deshalb wurde ein neues Konzept überlegt. Dieses Konzept

  16. Conduction band discontinuity and electron confinement at the Si[subscript x]Ge[subscript 1?x]/Ge interface

    E-Print Network [OSTI]

    Mazzeo, G.

    Germanium rich heterostructures can constitute a valid alternative to Silicon for the confinement of single electron spins. The conduction band discontinuity in SiGe/Ge heterostructures grown on pure germanium substrate ...

  17. Shell-Based Support Structures for Nb3Sn Accelerator Quadrupole Magnets

    E-Print Network [OSTI]

    Ferracin, Paolo

    2010-01-01T23:59:59.000Z

    similarly to the outer shell, they significantly increasedof Technology Quadrupole Shell (TQS) Magnet Models forSHELL-BASED SUPPORT STRUCTURES FOR NB 3 SN ACCELERATOR

  18. Surface electronic states in three-dimensional SnO{sub 2} nanostructures

    SciTech Connect (OSTI)

    Kucheyev, S.O.; Baumann, T.F.; Sterne, P.A.; Wang, Y.M.; Buuren, T. van; Hamza, A.V.; Terminello, L.J.; Willey, T.M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2005-07-15T23:59:59.000Z

    The electronic structure of three-dimensional SnO{sub 2} nanostructures (aerogels) is studied by soft x-ray absorption near-edge structure (XANES) spectroscopy. High-resolution O K-edge and Sn M{sub 3}- and M{sub 4,5}-edge XANES spectra of monolithic nanocrystalline rutile SnO{sub 2} aerogels with different surface areas (i.e., different surface-to-volume atom fractions) are compared with spectra of full-density rutile SnO{sub 2} and tetragonal SnO. Spectra are interpreted based on the electronic densities of states in SnO{sub 2} calculated with both cluster (self-consistent real-space multiple scattering) and band-structure (linear muffin-tin orbital) methods. Results show that, in contrast to the currently widely accepted picture, the presence of undercoordinated surface atoms not only affects the Fermi level position but also changes the structure of the conduction band by introducing additional Sn-related electronic states close to the conduction band minimum. These additional states are due to oxygen deficiency and are attributed to a surface reconstruction of SnO{sub 2} nanoparticles forming the aerogel skeleton. Results of this study are important for understanding the physical processes underlying the performance of gas sensors based on SnO{sub 2} nanostructures.

  19. Structural, optical and ethanol sensing properties of Cu-doped SnO{sub 2} nanowires

    SciTech Connect (OSTI)

    Johari, Anima, E-mail: animajohari@gmail.com; Sharma, Manish [Center for Applied Research in Electronics (CARE), IIT Delhi, Hauz khas, New Delhi-110016 (India); Johari, Anoopshi [THDC Institute of Hydropower Institute of Engineering and Technology, Tehri-249124 (India); Bhatnagar, M. C. [Physics Department, IIT Delhi, Hauz khas, New Delhi-110016 (India)

    2014-04-24T23:59:59.000Z

    In present work, one-dimensional nanostructure of Cu-doped Tin oxide (SnO{sub 2}) was synthesized by using thermal evaporation method in a tubular furnace under Nitrogen (N{sub 2}) ambience. The growth was carried out at atmospheric pressure. SEM and TEM images reveal the growth of wire-like nanostructures of Cu-doped SnO{sub 2} on Si substrate. The XRD analysis confirms that the synthesized SnO{sub 2} nanowires have tetragonal rutile structure with polycrystalline nature and X-ray diffraction pattern also showed that Cu gets incorporated into the SnO{sub 2} lattice. EDX spectra confirm the doping of Cu into SnO{sub 2} nanowires and atomic fraction of Cu in nanowires is ? 0.5 at%. The Vapor Liquid Solid (VLS) growth mechanism for Cu-doped SnO{sub 2} nanowires was also confirmed by EDX spectra. The optical properties of as grown Cu-doped SnO{sub 2} nanowires were studied by using UV-vis spectra which concludes the band gap of about 3.7 eV. As synthesized single Cu-doped SnO{sub 2} nanowire based gas sensor exhibit relatively good performance to ethanol gas. This sensing behaviour offers a suitable application of the Cu-doped SnO{sub 2} nanowire sensor for detection of ethanol gas.

  20. Annealing effect for SnS thin films prepared by high-vacuum evaporation

    SciTech Connect (OSTI)

    Revathi, Naidu, E-mail: revathi.naidu@ttu.ee; Bereznev, Sergei; Loorits, Mihkel; Raudoja, Jaan; Lehner, Julia; Gurevits, Jelena; Traksmaa, Rainer; Mikli, Valdek; Mellikov, Enn; Volobujeva, Olga [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086 (Estonia)

    2014-11-01T23:59:59.000Z

    Thin films of SnS are deposited onto molybdenum-coated soda lime glass substrates using the high-vacuum evaporation technique at a substrate temperature of 300?°C. The as-deposited SnS layers are then annealed in three different media: (1) H{sub 2}S, (2) argon, and (3) vacuum, for different periods and temperatures to study the changes in the microstructural properties of the layers and to prepare single-phase SnS photoabsorber films. It is found that annealing the layers in H{sub 2}S at 400?°C changes the stoichiometry of the as-deposited SnS films and leads to the formation of a dominant SnS{sub 2} phase. Annealing in an argon atmosphere for 1?h, however, causes no deviations in the composition of the SnS films, though the surface morphology of the annealed SnS layers changes significantly as a result of a 2?h annealing process. The crystalline structure, surface morphology, and photosensitivity of the as-deposited SnS films improves significantly as the result of annealing in vacuum, and the vacuum-annealed films are found to exhibit promising properties for fabricating complete solar cells based on these single-phase SnS photoabsorber layers.

  1. 33rd International Lie`ge Colloquium on Ocean Dynamics Lie`ge, Belgium, May 711, 2001

    E-Print Network [OSTI]

    Leonard, John J.

    Preface 33rd International Lie`ge Colloquium on Ocean Dynamics Lie`ge, Belgium, May 7­11, 2001 The International Lie`ge Colloquium on Ocean Dynamics is organized annually. The topic differs from year to year. Assembling a group of active and eminent scien- tists from various countries and often different disci

  2. Properties of excited states in {sup 77}Ge.

    SciTech Connect (OSTI)

    Kay, B. P.; Chiara, C. J.; Schiffer, J. P.; Kondev, F. G.; Zhu, S.; Carpenter, M. P.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Seweryniak, D.; Stefanescu, I.; Univ. of Maryland; Horia-Hulubei National Inst. for Physics and Nuclear Engineering

    2009-07-01T23:59:59.000Z

    The nucleus {sup 77}Ge was studied through the {sup 76}Ge({sup 13}C,{sup 12}C){sup 77}Ge reaction at a sub-Coulomb energy. The angular distributions of rays depopulating excited states in {sup 77}Ge were measured in order to constrain spin and parity assignments. Some of these assignments are of use in connection with neutrinoless double beta decay, where the population of states near the Fermi surface of {sup 76}Ge was recently explored using transfer reactions.

  3. Deuteron breakup pd->(pp){sub s}n with forward emission of a fast {sup 1}S{sub 0} diproton

    SciTech Connect (OSTI)

    Dymov, S.; Yaschenko, S. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, D-91058 Erlangen (Germany); Laboratory of Nuclear Problems, JINR, RU-141980 Dubna (Russian Federation); Komarov, V.; Macharashvili, G.; Uzikov, Yu.; Azarian, T.; Kulikov, A.; Kurbatov, V.; Merzliakov, S.; Zalikhanov, B.; Zhuravlev, N. [Laboratory of Nuclear Problems, JINR, RU-141980 Dubna (Russian Federation); Imambekov, O. [Laboratory of Nuclear Problems, JINR, RU-141980 Dubna (Russian Federation); Kazakh National University, KZ-050038, Almaty (Kazakhstan); Buescher, M.; Hartmann, M.; Hejny, V.; Kacharava, A.; Nekipelov, M.; Ohm, H.; Rathmann, F.; Seyfarth, H. [Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany)

    2010-04-15T23:59:59.000Z

    The deuteron breakup reaction pd->(pp){sub s}n, where (pp){sub s} is a fast proton pair emitted in forward direction with small excitation energy E{sub pp}<3 MeV, has been studied at proton beam energies of 0.5-2.0 GeV using the ANKE spectrometer at COSY-Juelich. The differential c.m. cross sections are measured in complete kinematics and provide angular distributions of the neutron emission angle in the range theta{sub n}=168 deg. - 180 deg., the dependence on beam energy at theta{sub n}=180 deg., angular distributions of the direction of the proton in the pp rest frame, and distributions of the excitation energy E{sub pp} of the proton pair. The obtained data are analyzed on the basis of theoretical models previously developed for the pd->dp process in a similar kinematics and properly modified for the diproton channel in pd->(pp){sub s}n. It is shown that the measured observables are highly sensitive to the short-range part of the nucleon-nucleon interaction.

  4. Role of nucleation sites on the formation of nanoporous Ge

    SciTech Connect (OSTI)

    Yates, B. R.; Darby, B. L.; Jones, K. S. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611-6400 (United States); Elliman, R. G. [Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

    2012-09-24T23:59:59.000Z

    The role of nucleation sites on the formation of nanoporous Ge was investigated. Three Ge films with different spherical or columnar pore morphologies to act as inherent nucleation sites were sputtered on (001) Ge. Samples were implanted 90 Degree-Sign from incidence at 300 keV with fluences ranging from 3.0 Multiplication-Sign 10{sup 15} to 3.0 Multiplication-Sign 10{sup 16} Ge{sup +}/cm{sup 2}. Electron microscopy investigations revealed varying thresholds for nanoporous Ge formation and exhibited a stark difference in the evolution of the Ge layers based on the microstructure of the initial film. The results suggest that the presence of inherent nucleation sites significantly alters the onset and evolution of nanoporous Ge.

  5. Isoscalar Breathing Mode State in Zr-90 and Sn-116

    E-Print Network [OSTI]

    Rozsa, C. M.; Youngblood, David H.; Bronson, J. D.; Lui, YW; Garg, U.

    1980-01-01T23:59:59.000Z

    PHYSICAL RKVIK% C VOLUIHE 21, NUMBER 4 Isoscalar breathing mode state in Zr and "Sn C. M. Rozsa, D. H. Youngblood, J. D. Bronson, Y.-%. Lui, and U. Garg Cyclotron Institute, Texas AckM University, College Station, Texas 77843 (Received 5..., BRONSON, LUI, AND GARG larger opening and served to catch some particles scattered from the first set. For measurements at 0', the beam was passed into the spectrograph and one set of brass defining slits with an open- ing of 6.4' horizontally by 3.V...

  6. SN-03 Power Rate Case (rates/ratecases)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection245C Unlimited ReleaseWelcome to theAbsorptionFinal Proposal:2003 SN

  7. Monolayer Passivation of Ge(100) Surface via Nitridation and Oxidation Joon Sung Leea,b

    E-Print Network [OSTI]

    Kummel, Andrew C.

    Monolayer Passivation of Ge(100) Surface via Nitridation and Oxidation Joon Sung Leea,b , Sarah R passivation of Ge(100) surface via formation of Ge-N and Ge-O surface species was studied using scanning cyclotron resonance (ECR) plasma source formed an ordered Ge-N structure on a Ge(100) surface at 500o C. DFT

  8. Prompt Gamma Rays in {sup 77}Ge after Neutron Capture on {sup 76}Ge

    SciTech Connect (OSTI)

    Meierhofer, Georg; Grabmayr, Peter; Jochum, Josef [Physikalisches Institut, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 14, 72076 Tuebingen (Germany); Canella, Lea [Institut fuer Radiochemie, Technische Universitaet Muenchen, Walther-Meissner-Str. 3, 85748 Garching (Germany); Jolie, Jan; Kudejova, Petra; Warr, Nigel [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Cologne (Germany)

    2009-01-28T23:59:59.000Z

    The observation of neutrinoless double beta decay would be proof of the Majorana nature of the neutrino. Half-lives for these decays are very long (for {sup 76}Ge:>10{sup 25} y), so background reduction and rejection is the major task for double beta experiments. The GERDA (GERmanium Detector Array) experiment at the Gran Sasso Laboratory of the INFN (LNGS) searches for neutrinoless double beta decay of {sup 76}Ge. The isotope {sup 76}Ge is an ideal candidate because it can be used as source and detector at the same time. A large remaining contribution to the background arises from the prompt gamma cascade after neutron capture by {sup 76}Ge followed by {beta}{sup -}-decay of {sup 77}Ge. Since the prompt gamma decay scheme is poorly known, measurements with isotopically enriched Germanium samples were carried out at the PGAA facility at the research reactor FRM II (Munich). With the known prompt gamma spectrum it will be possible to improve the overall veto efficiency of the GERDA experiment.

  9. Probing the Failure Mechanism of SnO2 Nanowires for Sodium-ion Batteries

    SciTech Connect (OSTI)

    Gu, Meng; Kushima, Akihiro; Shao, Yuyan; Zhang, Jiguang; Liu, Jun; Browning, Nigel D.; Li, Ju; Wang, Chong M.

    2013-09-30T23:59:59.000Z

    Non-lithium metals such as sodium have attracted wide attention as a potential charge carrying ion for rechargeable batteries, performing the same role as lithium in lithium- ion batteries. As sodium and lithium have the same +1 charge, it is assumed that what has been learnt about the operation of lithium ion batteries can be transferred directly to sodium batteries. Using in-situ TEM, in combination with DFT calculations, we probed the structural and chemical evolution of SnO2 nanowire anodes in Na-ion batteries and compared them quantitatively with results from Li-ion batteries [Science 330 (2010) 1515]. Upon Na insertion into SnO2, a displacement reaction occurs, leading to the formation of amorphous NaxSn nanoparticles covered by crystalline Na2O shell. With further Na insertion, the NaxSn core crystallized into Na15Sn4 (x=3.75). Upon extraction of Na (desodiation), the NaxSn core transforms to Sn nanoparticles. Associated with a volume shrinkage, nanopores appear and metallic Sn particles are confined in hollow shells of Na2O, mimicking a peapod structure. These pores greatly increase electrical impedance, therefore naturally accounting for the poor cyclability of SnO2. DFT calculations indicate that Na+ diffuses 30 times slower than Li+ in SnO2, in agreement with in-situ TEM measurement. Insertion of Na can chemo-mechanically soften the reaction product to greater extent than in lithiation. Therefore, in contrast to the lithiation of SnO2, no dislocation plasticity was seen ahead of the sodiation front. This direct comparison of the results from Na and Li highlights the critical role of ionic size and electronic structure of different ionic species on the charge/discharge rate and failure mechanisms in these batteries.

  10. Material properties in SiGe/Ge quantum wells Rebecca K. Schaevitz*, Jonathan E. Roth, Onur Fidaner, and David A. B. Miller

    E-Print Network [OSTI]

    Miller, David A. B.

    Material properties in SiGe/Ge quantum wells Rebecca K. Schaevitz*, Jonathan E. Roth, Onur Fidaner *Corresponding author: rschaevitz@stanford.edu Abstract: Photocurrent measurements in Ge quantum wells parameters for design of high-performance SiGe/Ge quantum well optoelectronics on silicon. Germanium

  11. Ge/SiGe Quantum Confined Stark Effect Modulators on Silicon James S. Harris, Yu-Hsuan Kuo, and David A. B. Miller

    E-Print Network [OSTI]

    Miller, David A. B.

    Ge/SiGe Quantum Confined Stark Effect Modulators on Silicon James S. Harris, Yu-Hsuan Kuo bandwidth have been demonstrated [4]. 2. Quantum well design Ge is an indirect band gap material, but it has. In order to have good quantum confinement, SiGe barriers are used since Si and Ge have a very high direct

  12. FEM Analysis of Nb-Sn Rutherford-type Cables

    SciTech Connect (OSTI)

    Barzi, Emanuela; Gallo, Giuseppe; Neri, Paolo; /Fermilab

    2011-01-01T23:59:59.000Z

    An important part of superconducting accelerator magnet work is the conductor. To produce magnetic fields larger than 10 T, brittle conductors are typically used. For instance, for Nb{sub 3}Sn the original round wire, in the form of a composite of Copper, Niobium and Tin, is assembled into a so-called Rutherford-type cable, which is used to wind the magnet. The magnet is then subjected to a high temperature heat treatment to produce the chemical reactions that make the material superconducting. At this stage the superconductor is brittle and its superconducting properties sensitive to strain. This work is based on the development of a 2D finite element model, which simulates the mechanical behavior of Rutherford-type cable before heat treatment. The model was applied to a number of different cable architectures. To validate a critical criterion adopted into the single Nb-Sn wire analysis, the results of the model were compared with those measured experimentally on cable cross sections.

  13. THE EFFECT OF A COSMIC RAY PRECURSOR IN SN 1006?

    SciTech Connect (OSTI)

    Rakowski, Cara E. [Space Science Division, Naval Research Laboratory, Code 7671, Washington, DC 20375 (United States); Laming, J. Martin [Space Science Division, Naval Research Laboratory, Code 7674L, Washington, DC 20375 (United States); Hwang, Una [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Eriksen, Kristoffer A.; Hughes, John P. [Rutgers, State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Ghavamian, Parviz [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2011-07-01T23:59:59.000Z

    Like many young supernova remnants, SN 1006 exhibits what appear to be clumps of ejecta close to or protruding beyond the main blast wave. In this Letter, we examine three such protrusions along the east rim. They are semi-aligned with ejecta fingers behind the shock-front and exhibit emission lines from O VII and O VIII. We first interpret them in the context of an upstream medium modified by the saturated non-resonant Bell instability which enhances the growth of Rayleigh-Taylor instabilities when advected post-shock. We discuss their apparent periodicity if the spacing is determined by properties of the remnant or by a preferred size scale in the cosmic ray precursor. We also briefly discuss the alternative that these structures have an origin in the ejecta structure of the explosion itself. In this case, the young evolutionary age of SN 1006 would imply density structure within the outermost layers of the explosion with potentially important implications for deflagration and detonation in thermonuclear supernova explosion models.

  14. Improving thermostability of CrO{sub 2} thin films by doping with Sn

    SciTech Connect (OSTI)

    Ding, Yi; Wang, Ziyu; Liu, Shuo; Shi, Jing; Yin, Di, E-mail: dyin@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Yuan, Cheng; Lu, Zhihong, E-mail: zludavid@live.com [School of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081 (China); Xiong, Rui, E-mail: xiongrui@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Wuhan 430062 (China)

    2014-09-01T23:59:59.000Z

    Chromium dioxide (CrO{sub 2}) is an ideal material for spin electronic devices since it has almost 100% spin polarization near Fermi level. However, it is thermally unstable and easily decomposes to Cr{sub 2}O{sub 3} even at room temperature. In this study, we try to improve the thermal stability of CrO{sub 2} thin films by doping with Sn whose oxide has the same structure as CrO{sub 2}. High quality epitaxial CrO{sub 2} and Sn-doped CrO{sub 2} films were grown on single crystalline TiO{sub 2} (100) substrates by chemical vapor deposition. Sn{sup 4+} ions were believed to be doped into CrO{sub 2} lattice and take the lattice positions of Cr{sup 4+}. The magnetic measurements show that Sn-doping leads to a decrease of magnetocrystalline anisotropy. The thermal stabilities of the films were evaluated by annealing the films at different temperatures. Sn-doped films can withstand a temperature up to 510?°C, significantly higher than what undoped films can do (lower than 435?°C), which suggests that Sn-doping indeed enhances the thermal stability of CrO{sub 2} films. Our study also indicates that Sn-doping may not change the essential half metallic properties of CrO{sub 2}. Therefore, Sn-doped CrO{sub 2} is expected to be very promising for applications in spintronic devices.

  15. Surface morphologies of SnO2(110) Matthias Batzill *, Khabibulakh Katsiev, Ulrike Diebold *

    E-Print Network [OSTI]

    Diebold, Ulrike

    ; Surface relaxation and reconstruction; Surface structure, morphology, roughness, and topography; TinSurface morphologies of SnO2(110) Matthias Batzill *, Khabibulakh Katsiev, Ulrike Diebold), and low energy electron diffraction (LEED) was used to investigate the surface morphology of SnO2(1 1 0

  16. Modeling non-isothermal intermetallic layer growth in the 63Sn-37Pb/Cu system

    SciTech Connect (OSTI)

    Vianco, P.T.; Hopkins, P.L.; Erickson, K.L.; Frear, D.R.; Davidson, R.

    1996-12-31T23:59:59.000Z

    A model describing diffusion-controlled growth of multiple intermetallic layers and the displacement of the interfaces between layers was developed and implemented in a 1-D computer code based on method-of-lines. The code was applied to analysis of intermetallic layer growth in isothermal solder aging experiments performed with 100 Sn/Cu and 63Sn-37Pb/Cu solder-substrate systems. Analyses indicated that intermetallic layer growth was consistent with a bulk diffusion mechanism involving Cu and/or Sn. In this work, nonisothermal solder-aging experiments were done with the 63Sn- 37Pb/Cu system using two temperature histories (4 cycles/day between 223-443 K, and 72 cycles/day between 223-443 K). Isothermal experiments were also done at 443 K. Thickness of Cu{sub 3}Sn and Cu{sub 6}Sn{sub 5} intermetallic layers were determined vs time for each temperature history. An updated version of the model and code were used to predict the intermetallic layer growth. Arrhenius expressions for diffusion coefficients in both Cu3Sn and Cu6Sn5 layers were determined. Agreement between prediction and experiment was generally good. In some cases, predicted layer growth was less than experiment, but within error. This paper describes the nonisothermal experiments and a comparison of predicted and observed layer growth vs time.

  17. Fabrication of Microfibre-nanowire Junction Arrays of ZnO/SnO2 Composite

    E-Print Network [OSTI]

    Iglic, Ales

    nanocomposite sensitized with a D35-cpdt dye was investigated. A dye-sensitized solar cell (DSSC) with a Zn discussed. Keywords ZnO/SnO2 Nanocomposite, Dye-sensitized Solar Cell, Nanostructured Surfaces 1O/SnO2 nanocomposite photoanode based on a cobalt electrolyte achieved a solar-to-electricity conversion

  18. XRF 100316D / SN 2010bh and the Nature of Gamma Ray Burst Supernovae

    E-Print Network [OSTI]

    Cano, Z; Guidorzi, C; Kobayashi, S; Levan, A J; Tanvir, N R; Wiersema, K; D'Avanzo, P; Fruchter, A S; Garnavich, P; Gomboc, A; Gorosabel, J; Kasen, D; Kopac, D; Margutti, R; Mazzali, P A; Melandri, A; Mundell, C G; Nugent, P E; Pian, E; Smith, R J; Steele, I; Wijers, R A M J; Woosley, S E

    2011-01-01T23:59:59.000Z

    We present ground-based and HST optical and infrared observations of XRF 100316D / SN 2010bh. It is seen that the optical light curves of SN 2010bh evolve at a faster rate than the archetype GRB-SN 1998bw, but at a similar rate to SN 2006aj, a supernova that was spectroscopically linked with XRF 060218, and at a similar rate to non-GRB associated type Ic SN 1994I. We estimate the rest-frame extinction of this event from our optical data to be E(B-V)=0.18 +/- 0.08 mag. We find the V-band absolute magnitude of SN 2010bh to be M_{V}=-18.62 +/- 0.08, which is the faintest peak V-band magnitude observed to-date for a spectroscopically-confirmed GRB-SNe. When we investigate the origin of the flux at t-t_{o}=0.598 days, it is shown that the light is not synchrotron in origin, but is likely coming from the supernova shock break-out. We then use our optical and infrared data to create a quasi-bolometric light curve of SN 2010bh which we model with a simple analytical formula. The results of our modeling imply that SN ...

  19. A PANCHROMATIC VIEW OF THE RESTLESS SN 2009ip REVEALS THE EXPLOSIVE EJECTION OF A MASSIVE STAR ENVELOPE

    E-Print Network [OSTI]

    Friedman, Andrew Samuel

    The double explosion of SN 2009ip in 2012 raises questions about our understanding of the late stages of massive star evolution. Here we present a comprehensive study of SN 2009ip during its remarkable rebrightenings. ...

  20. Thermal and electrical stabilities of solid nitrogen (SN2) cooled YBCO coated conductors for HTS magnet applications

    E-Print Network [OSTI]

    Song, J. B.

    Recently, a cooling system using a solid cryogen such as solid nitrogen (SN2), was introduced for high temperature superconducting (HTS) magnet applications. In order to apply the SN2 cooling system successfully to HTS ...

  1. Electrochemical Insertion/extraction of Lithium in Multiwall Carbon Nanotube/Sb and SnSb?.? Nanocomposites

    E-Print Network [OSTI]

    Chen, Wei Xiang

    Multiwall carbon nanotubes (CNTs) were synthesized by catalytic chemical vapor deposition of acetylene and used as templates to prepare CNT-Sb and CNT-SnSb?.? nanocomposites via the chemical reduction of SnCl? and SbCl? ...

  2. Growth of CrO[subscript 2] coated single crystalline (SnO[subscript 2]) tin oxide nanowires

    E-Print Network [OSTI]

    Miao, Guo-Xing

    Single crystalline tin oxide (SnO[subscript 2]) nanowires have been synthesized by carbothermal reduction of SnO[subscript 2] nanopowder followed by thermal evaporation of the reduced precursor and growth via the ...

  3. Novel synthesis of high phase-purity Mg2SnO4 from metallic precursors via powder metallurgy route

    E-Print Network [OSTI]

    Azad, Abdul-Majeed

    Novel synthesis of high phase-purity Mg2SnO4 from metallic precursors via powder metallurgy route of composition Mg2Sn was prepared by the conventional powder metallurgy route. This up on heating in air under

  4. Bio390 Study Questions for S-N Ch. 2 --Blood 1. Know S-N's list of 10 general functions/properties of blood.

    E-Print Network [OSTI]

    Prestwich, Ken

    effects of temperature, pH, CO2, PO4 2-, and ionic strength on the ability of hemoglobin to bind oxygenBio390 Study Questions for S-N Ch. 2 -- Blood Spring '01 1. Know S-N's list of 10 general functions/properties tends to decrease as body size increases. How does a relatively high P50 serve as an adaptation in small

  5. Upgrade of CEBAF from 6-GeV To 12-GeV: Status

    SciTech Connect (OSTI)

    Harwood, Leigh H.

    2013-04-01T23:59:59.000Z

    The CEBAF accelerator is being upgraded from 6 GeV to 12 GeV by the US Department of Energy. The accelerator upgrade is being done within the existing tunnel footprint. The accelerator upgrade includes: 10 new srfbased high-performance cryomodules plus RF systems, doubling the 2K helium plants capability, upgrading the existing beamlines to operate at nearly double the original performance envelope, and adding a beamline to a new experimental area. Construction is over 75% complete with final completion projected for late FY13. Details of the upgrade and status of the work will be presented.

  6. Interface and nanostructure evolution of cobalt germanides on Ge(001)

    SciTech Connect (OSTI)

    Grzela, T., E-mail: grzela@ihp-microelectronics.com; Schubert, M. A. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Koczorowski, W. [London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH,United Kingdom (United Kingdom); Institute of Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); Capellini, G. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Dipartimento di Scienze, Università degli Studi Roma Tre, I-00146 Roma (Italy); Czajka, R. [Institute of Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); Radny, M. W. [Institute of Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); School of Mathematical and Physical Sciences, The University of Newcastle, University Drive, Callaghan NSW, 2308 (Australia); Curson, N.; Schofield, S. R. [London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH,United Kingdom (United Kingdom); Schroeder, T. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); BTU Cottbus, Konrad-Zuse Str. 1, 03046 Cottbus (Germany)

    2014-02-21T23:59:59.000Z

    Cobalt germanide (Co{sub x}Ge{sub y}) is a candidate system for low resistance contact modules in future Ge devices in Si-based micro and nanoelectronics. In this paper, we present a detailed structural, morphological, and compositional study on Co{sub x}Ge{sub y} formation on Ge(001) at room temperature metal deposition and subsequent annealing. Scanning tunneling microscopy and low energy electron diffraction clearly demonstrate that room temperature deposition of approximately four monolayers of Co on Ge(001) results in the Volmer Weber growth mode, while subsequent thermal annealing leads to the formation of a Co-germanide continuous wetting layer which evolves gradually towards the growth of elongated Co{sub x}Ge{sub y} nanostructures. Two types of Co{sub x}Ge{sub y} nanostructures, namely, flattop- and ridge-type, were observed and a systematic study on their evolution as a function of temperature is presented. Additional transmission electron microscopy and x-ray photoemission spectroscopy measurements allowed us to monitor the reaction between Co and Ge in the formation process of the Co{sub x}Ge{sub y} continuous wetting layer as well as the Co{sub x}Ge{sub y} nanostructures.

  7. SiGe thin-film structures for solar cells

    SciTech Connect (OSTI)

    Bremond, G.; Daami, A.; Laugier, A. [Inst. National des Sciences Appliquees de Lyon, Villeurbanne (France). Lab. de Physique de la Matiere] [and others

    1998-12-31T23:59:59.000Z

    In order to study their applicability as the active base material in Si thin crystalline film solar cell technology, SiGe relaxed layers grown by Liquid Phase Epitaxy (LPE) and Chemical Vapor Deposition (CVD) on Si substrates are investigated by optical and electrical measurements (TEM, EXD, PL, EBIC). The main results of this work is to point out the improvement of the SiGe active base layer by using smooth Ge graded SiGe buffer layer and remote plasma hydrogenation. TEM, EXD, PL experiments show the effect of the Ge graded buffer layer grown using LPE, by confining the threading dislocations in the SiGe buffer layer close to the Si/SiGe interface. EBIC measurements reveal low recombination activity of dislocations at 300 K providing the diffusion length exceeds the 15 {micro}m layer thickness. The enhanced luminescence of SiGe near bandgap indicates that remote plasma hydrogenation induces a decrease of the non-radiative recombination pathways due to dislocations on CVD layers where defect recombinations dominate as indicated by EBIC measurements. This study points out the importance of controlling relaxed SiGe layers with good minority carrier recombination quality as a key issue for the optimization of new SiGe/Si based solar cells.

  8. Spreading of Sn-Ag solders on FeNi alloys

    SciTech Connect (OSTI)

    Saiz, Eduardo; Hwang, C-W.; Suganuma, Katsuaki; Tomsia, Antoni P.

    2003-02-28T23:59:59.000Z

    The spreading of Sn-3Ag-xBi solders on Fe-42Ni has been studied using a drop transfer setup. Initial spreading velocities as fast as {approx}0.5 m/s have been recorded. The results are consistent with a liquid front moving on a metastable, flat, unreacted substrate and can be described by using a modified molecular-kinetic model for which the rate controlling step is the movement of one atom from the liquid to the surface of the solid substrate. Although the phase diagram predicts the formation of two Fe-Sn intermetallics at the solder/substrate interface in samples heated at temperatures lower than 513 C, after spreading at 250 C only a thin FeSn reaction layer could be observed. Two interfacial layers (FeSn and FeSn2) were found after spreading at 450 C.

  9. Origin of carrier generation in photovoltaic perovskite variant Cs2SnI6

    E-Print Network [OSTI]

    Xiao, Zewen; Kamiya, Toshio

    2015-01-01T23:59:59.000Z

    Cs2SnI6 is an air-stable & non-toxic variant of perovskite-type photovoltaic materials. In this letter, stability of intrinsic defects in Cs2SnI6 was examined by density functional theory calculations. We found that iodine vacancy and tin interstitial are the dominant defects, mainly responsible for the intrinsic n-type conductivity in Cs2SnI6. However, the transition levels of the dominant defects are deep, which makes it difficult to achieve high-density n-type doping. Tin vacancy is expected for p-type doping, but it has a very high formation energy > 3.6 eV because of the strong Sn-I covalent bonds and can hardly be generated. Instead, cesium vacancy is formed at an extremely Cs-poor condition and explains already-reported p-type conductivity by SnI2 doping.

  10. The peculiar case of the "double-humped" super-luminous supernova SN2006oz

    E-Print Network [OSTI]

    Rachid Ouyed; Denis Leahy

    2012-02-11T23:59:59.000Z

    SN2006oz is a super-luminous supernova with a mysterious bright precursor that has resisted explanation in standard models. However, such a precursor has been predicted in the dual-shock quark nova (dsQN) model of super-luminous supernovae -- the precursor is the SN event while the main light curve of the SLSN is powered by the Quark-Nova (QN; explosive transition of the neutron star to a quark star). As the SN is fading, the QN re-energizes the SN ejecta, producing a "double-humped" light curve. In this paper, we show the dsQN model successfully reproduces the observed light curve of SN2006oz.

  11. Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses

    SciTech Connect (OSTI)

    Kelly, Patrick L.; /KIPAC, Menlo Park /SLAC; Hicken, Malcolm; /Harvard-Smithsonian Ctr. Astrophys.; Burke, David L.; /KIPAC, Menlo Park /SLAC; Mandel, Kaisey S.; Kirshner, Robert P.; /Harvard-Smithsonian Ctr. Astrophys.

    2010-05-03T23:59:59.000Z

    From Sloan Digital Sky Survey u{prime} g{prime} r{prime} i{prime} z{prime} imaging, we estimate the stellar masses of the host galaxies of 70 low redshift SN Ia (0.015 < z < 0.08) from the hosts absolute luminosities and mass-to-light ratios. These nearby SN were discovered largely by searches targeting luminous galaxies, and we find that their host galaxies are substantially more massive than the hosts of SN discovered by the flux-limited Supernova Legacy Survey. Testing four separate light curve fitters, we detect {approx}2.5{sigma} correlations of Hubble residuals with both host galaxy size and stellar mass, such that SN Ia occurring in physically larger, more massive hosts are {approx}10% brighter after light curve correction. The Hubble residual is the deviation of the inferred distance modulus to the SN, calculated from its apparent luminosity and light curve properties, away from the expected value at the SN redshift. Marginalizing over linear trends in Hubble residuals with light curve parameters shows that the correlations cannot be attributed to a light curve-dependent calibration error. Combining 180 higher-redshift ESSENCE, SNLS, and HigherZ SN with 30 nearby SN whose host masses are less than 10{sup 10.8} M{circle_dot} n a cosmology fit yields 1 + w = 0.22{sub -0.108}{sup +0.152}, while a combination where the 30 nearby SN instead have host masses greater than 10{sup 10.8} M{circle_dot} yields 1 + w = ?0.03{sub -0.143}{sup +0.217}. Progenitor metallicity, stellar population age, and dust extinction correlate with galaxy mass and may be responsible for these systematic effects. Host galaxy measurements will yield improved distances to SN Ia.

  12. Patent Record Announcement | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeedingBiomassPPPO WebsitePalms Village ResortEnergyL L 2PatentGE's E.

  13. Crowdsourcing Software Announcement | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power Administration would likeConstitution4 Department of EnergyCross-SectorDepartment ofGE, MIT

  14. Crowdsourcing Software Award | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power Administration would likeConstitution4 Department of EnergyCross-SectorDepartment ofGE,

  15. Brazil Technology Center | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccess Stories Site MapSolarAboutTaubmanBiofuels Research at GE's

  16. Study of the low-lying states of Ge2 and Ge2 using negative ion zero electron kinetic energy spectroscopy

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Study of the low-lying states of Ge2 and Ge2 using negative ion zero electron kinetic energy The low-lying states of Ge2 and Ge2 are probed using negative ion zero electron kinetic energy ZEKE spectroscopy. The ZEKE spectrum of Ge2 yields an electron affinity of 2.035 0.001 eV for Ge2, as well as term

  17. Characterization of Cu{sub 6}Sn{sub 5} intermetallic powders produced by water atomization and powder heat treatment

    SciTech Connect (OSTI)

    Tongsri, Ruangdaj, E-mail: ruangdt@mtec.or.th [Powder Metallurgy Research and Development Unit (PM-RDU), National Metal and Materials Technology Center, 114 Paholyothin, Klong 1, Klong Luang, Pathum Thani 12120 (Thailand); Yotkaew, Thanyaporn, E-mail: thanyy@mtec.or.th [Powder Metallurgy Research and Development Unit (PM-RDU), National Metal and Materials Technology Center, 114 Paholyothin, Klong 1, Klong Luang, Pathum Thani 12120 (Thailand); Krataitong, Rungtip, E-mail: rungtipk@mtec.or.th [Powder Metallurgy Research and Development Unit (PM-RDU), National Metal and Materials Technology Center, 114 Paholyothin, Klong 1, Klong Luang, Pathum Thani 12120 (Thailand); Wila, Pongsak, E-mail: pongsakw@mtec.or.th [Powder Metallurgy Research and Development Unit (PM-RDU), National Metal and Materials Technology Center, 114 Paholyothin, Klong 1, Klong Luang, Pathum Thani 12120 (Thailand); Sir-on, Autcharaporn, E-mail: autchars@mtec.or.th [Materials Characterization Research Unit (MCRU), National Metal and Materials Technology Center, 114 Paholyothin, Klong 1, Klong Luang, Pathum Thani 12120 (Thailand); Muthitamongkol, Pennapa, E-mail: pennapm@mtec.or.th [Materials Characterization Research Unit (MCRU), National Metal and Materials Technology Center, 114 Paholyothin, Klong 1, Klong Luang, Pathum Thani 12120 (Thailand); Tosangthum, Nattaya, E-mail: nattayt@mtec.or.th [Powder Metallurgy Research and Development Unit (PM-RDU), National Metal and Materials Technology Center, 114 Paholyothin, Klong 1, Klong Luang, Pathum Thani 12120 (Thailand)

    2013-12-15T23:59:59.000Z

    Since the Cu{sub 6}Sn{sub 5} intermetallic shows its importance in industrial applications, the Cu{sub 6}Sn{sub 5} intermetallic-containing powders, produced by a powder processing route with a high production rate, were characterized. The route consisted of water atomization of an alloy melt (Cu–61 wt.% Sn) and subsequent heat treatment of the water-atomized powders. Characterization of the water-atomized powders and their heated forms was conducted by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Fine water-atomized powder microstructures consisted of primary hexagonal ?-Cu{sub 6.25}Sn{sub 5} dendrites coexisting with interdendritic ?-Cu{sub 6.25}Sn{sub 5} + ?-Sn eutectic. Solidification of fine melt droplets was governed by surface nucleation and growth of the primary hexagonal ?-Cu{sub 6.25}Sn{sub 5} dendrites followed by ?-Cu{sub 6.25}Sn{sub 5} + ?-Sn eutectic solidification of the remnant liquid. In coarse melt droplets, nucleation and growth of primary ?-Cu{sub 3}Sn dendrites were followed by peritectic reaction (?-Cu{sub 3}Sn + liquid ? ?-Cu{sub 6.25}Sn{sub 5}) or direct crystallization of ?-Cu{sub 6.25}Sn{sub 5} phase from the undercooled melt. Finally, the ?-Cu{sub 6.25}Sn{sub 5} + ?-Sn eutectic solidification of the remnant liquid occurred. Heating of the water-atomized powders at different temperatures resulted in microstructural homogenization. The water-atomized powders with mixed phases were transformed to powders with single monoclinic ?-Cu{sub 6}Sn{sub 5} phase. - Highlights: • The Cu{sub 6}Sn{sub 5} intermetallic powder production route was proposed. • Single phase Cu{sub 6}Sn{sub 5} powders could be by water atomization and heating. • Water-atomized Cu–Sn powders contained mixed Cu–Sn phases. • Solidification and heat treatment of water-atomized Cu–Sn powders are explained.

  18. A New Look at the Galactic Diffuse GeV

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    ;Gamma-ray Detectors from 10s MeV to 100s GeV Gamma-rays' trajectories cannot be directly detected #12;Gamma-ray Detectors from 10s MeV to 100s GeV Gamma-rays' trajectories cannot be directly detected Physics 1 #12;Overview Diffuse gamma-ray emission The Galactic diffuse gamma-ray GeV excess Discussion

  19. Structure and vibrations of different charge Ge impurity in ?-quartz

    SciTech Connect (OSTI)

    Kislov, A. N., E-mail: a.n.kislov@urfu.ru; Mikhailovich, A. P., E-mail: a.n.kislov@urfu.ru; Zatsepin, A. F., E-mail: a.n.kislov@urfu.ru [Ural Federal University, 19 Mira St., Yekaterinburg, 620002 (Russian Federation)

    2014-10-21T23:59:59.000Z

    Atomic structure and localized vibrations of ??SiO{sub 2}:Ge are studied using computer modeling techniques. The simulation was carried out by the lattice dynamics calculation of the local density of vibrational states. Local structures parameters are calculated, localized symmetrized vibrations frequency caused by Ge impurity in different charge states are defined. The movements of atoms located near Ge impurity are analyzed and their contribution into localized vibrations of different type is evaluated.

  20. Relationship between morphologies and orientations of Cu{sub 6}Sn{sub 5} grains in Sn3.0Ag0.5Cu solder joints on different Cu pads

    SciTech Connect (OSTI)

    Tian, Yanhong, E-mail: tianyh@hit.edu.cn; Zhang, Rui; Hang, Chunjin; Niu, Lina; Wang, Chunqing

    2014-02-15T23:59:59.000Z

    The morphologies and orientations of Cu{sub 6}Sn{sub 5} intermetallic compounds in the Sn3.0Ag0.5Cu solder joints both on polycrystalline and single crystal Cu pads under different peak reflow temperatures and times above liquids were investigated. The relationship between Cu{sub 6}Sn{sub 5} grain orientations and morphologies was clarified. At the interface of Sn3.0Ag0.5Cu/polycrystalline Cu pad, scalloped Cu{sub 6}Sn{sub 5} intermetallic compounds formed at 250 °C and roof shape Cu{sub 6}Sn{sub 5} formed at 300 °C. Both scalloped Cu{sub 6}Sn{sub 5} and roof shape Cu{sub 6}Sn{sub 5} had a preferred orientation of (0001) plane being parallel to polycrystalline Cu pad surface. Besides, the percentage of large angle grain boundaries increased as the peak reflow temperature rose. At the interface of Sn3.0Ag0.5Cu/(111) single crystal Cu pad, the Cu{sub 6}Sn{sub 5} intermetallic compounds were mainly scallop-type at 250 °C and were prism type at 300 °C. The prismatic Cu{sub 6}Sn{sub 5} grains grew along the three preferred directions with the inter-angles of 60° on (111) single crystal Cu pad while along two perpendicular directions on (100) single crystal Cu pad. The orientation relationship between Cu{sub 6}Sn{sub 5} grains and the single crystal Cu pads was investigated by electron backscatter diffraction technology. In addition, two types of hollowed Cu{sub 6}Sn{sub 5} intermetallic compounds were found inside the joints of polycrystalline Cu pads. The long hexagonal Cu{sub 6}Sn{sub 5} strips were observed in the joints reflowing at 250 °C while the hollowed Cu{sub 6}Sn{sub 5} strips with the ‘?’ shape cross-sections appeared at 300 °C, which was attributed to the different grain growth rates of different Cu{sub 6}Sn{sub 5} crystal faces. - Highlights: • The orientation of interfacial Cu{sub 6}Sn{sub 5} grains was obtained by EBSD technology. • Two types of hollowed Cu{sub 6}Sn{sub 5} strips were found at different temperatures. • The formation mechanism of hollowed Cu{sub 6}Sn{sub 5} was elaborated based on Bravais law. • The relationship between Cu{sub 6}Sn{sub 5} grain orientations and morphologies was clarified.

  1. Structural and phonon transmission study of Ge-Au-Ge eutectically bonded interfaces

    SciTech Connect (OSTI)

    Knowlton, W.B. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley Lab., CA (United States). Materials Sciences Div.

    1995-07-01T23:59:59.000Z

    This thesis presents a structural analysis and phonon transparency investigation of the Ge-Au-Ge eutectic bond interface. Interface development was intended to maximize the interfacial ballistic phonon transparency to enhance the detection of the dark matter candidate WIMPs. The process which was developed provides an interface which produces minimal stress, low amounts of impurities, and insures Ge lattice continuity through the interface. For initial Au thicknesses of greater than 1,000 {angstrom} Au per substrate side, eutectic epitaxial growth resulted in a Au dendritic structure with 95% cross sectional and 90% planar Au interfacial area coverages. In sections in which Ge bridged the interface, lattice continuity across the interface was apparent. Epitaxial solidification of the eutectic interface with initial Au thicknesses < 500 A per substrate side produced Au agglomerations thereby reducing the Au planar interfacial area coverage to as little as 30%. The mechanism for Au coalescence was attributed to lateral diffusion of Ge and Au in the liquid phase during solidification. Phonon transmission studies were performed on eutectic interfaces with initial Au thicknesses of 1,000 {angstrom}, 500 {angstrom}, and 300 {angstrom} per substrate side. Phonon imaging of eutectically bonded samples with initial Au thicknesses of 300 {angstrom}/side revealed reproducible interfacial percent phonon transmissions from 60% to 70%. Line scan phonon imaging verified the results. Phonon propagation TOF spectra distinctly showed the predominant phonon propagation mode was ballistic. This was substantiated by phonon focusing effects apparent in the phonon imaging data. The degree of interface transparency to phonons and resulting phonon propagation modes correlate with the structure of the interface following eutectic solidification. Structural studies of samples with initial Au thickness of 1,000 {angstrom}/side appear to correspond with the phonon transmission study.

  2. GE Technology to Help Canada Province Meet Growing Energy Needs

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    funding and collaboration models at its European Global Research Center near Munich, Germany. Mark Little, GE's Senior Vice President and Chief Technology Officer, and thought...

  3. Limitless Hot Gas Path Cooling Design | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Organization at GE Global Research, one such potent combination already taking shape is Additive Manufacturing and High Pressure Turbine Blade Cooling. Additive Manufacturing...

  4. GE researchers perform simulations in pursuit of more efficient...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GE researchers perform simulations in pursuit of more efficient jet engines and wind turbines Author: John Spizzirri . July 1, 2014 Printer-friendly version The recent addition of...

  5. How Will We Explore Earth's Final Frontier? | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    see how technology is helping us understand, utilize and protect the last frontier on earth. At GE Global Research's Rio de Janiero location, researchers are developing...

  6. Media Advisory - Jefferson Lab 12 GeV Upgrade Groundbreaking...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for its 310 million 12 GeV Upgrade project. When: Tuesday, April 14, 2009. Where: CEBAF Center, Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue,...

  7. GE's Arnie Lund Discusses User Experience at an Industrial Scale...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    at an Industrial Scale Arnie Lund, manager of the UX Industrial Innovation Lab at GE Global Research in San Ramon, Calif, recently spoke to the Farstuff Podcast about...

  8. approaching cryogenic ge: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Very low Weinreb, Sander 2 Draft 040509 A new high-background-rejection dark matter Ge cryogenic Computer Technologies and Information Sciences Websites Summary: Draft...

  9. Titan propels GE wind turbine research into new territory | ornl...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Titan propels GE wind turbine research into new territory January 17, 2014 The amount of global electricity supplied by wind, the world's fastest growing energy source, is expected...

  10. The Destruction of the Circumstellar Ring of SN 1987A

    E-Print Network [OSTI]

    Fransson, Claes; Migotto, Katia; Pesce, Dominic; Challis, Peter; Chevalier, Roger A; France, Kevin; Kirshner, Robert P; Leibundgut, Bruno; Lundqvist, Peter; McCray, Richard; Spyromilio, Jason; Taddia, Francesco; Jerkstrand, Anders; Mattila, Seppo; Smith, Nathan; Sollerman, Jesper; Wheeler, J Craig; Crotts, Arlin; Garnavich, Peter; Heng, Kevin; Lawrence, Stephen S; Panagia, Nino; Pun, Chun S J; Sonneborn, George; Sugerman, Ben

    2015-01-01T23:59:59.000Z

    We present imaging and spectroscopic observations with HST and VLT of the ring of SN 1987A from 1994 to 2014. After an almost exponential increase of the shocked emission from the hotspots up to day ~8,000 (~2009), both this and the unshocked emission are now fading. From the radial positions of the hotspots we see an acceleration of these up to 500-1000 km/s, consistent with the highest spectroscopic shock velocities from the radiative shocks. In the most recent observations (2013 and 2014), we find several new hotspots outside the inner ring, excited by either X-rays from the shocks or by direct shock interaction. All of these observations indicate that the interaction with the supernova ejecta is now gradually dissolving the hotspots. We predict, based on the observed decay, that the inner ring will be destroyed by ~2025.

  11. Developmentof the 15 T Nb3Sn dipole HD2

    SciTech Connect (OSTI)

    Caspi, S.; Cheng, D.W.; Dietderich, D.R.; Hafalia, A.R.; Hannaford, C.R.; Higley, H.; Lietzke, A.F.; Lizarazo, J.; McInturff, A.D.; Sabbi, G.; Ferracin, P.

    2008-06-01T23:59:59.000Z

    The Superconducting Magnet Program at Lawrence Berkeley National Laboratory (LBNL) is continuing the development of HD2, a 1 m long Nb{sub 3}Sn dipole generating a dipole field of 15 T in a 36 mm clear bore. With tilted (flared) ends to avoid obstructing the beam path, HD2 represents a step towards the development of cost effective accelerator quality magnets. The design has been optimized to minimize geometric harmonics and to address iron saturation and conductor magnetization effects. The support structure is based on an external aluminum shell, pre-tensioned with pressurized bladders and interference keys. Aluminum axial rods and stainless steel end plates provide longitudinal support to the coil ends during magnet excitation. This paper reports on field quality optimization and magnet parameters. The design and fabrication of the coil and structure components, and results from coil winding, reaction, and potting are also presented.

  12. Nb3Sn Quadrupoles Designs For The LHC Upgrades

    SciTech Connect (OSTI)

    Felice, Helene

    2008-05-19T23:59:59.000Z

    In preparation for the LHC luminosity upgrades, high field and large aperture Nb{sub 3}Sn quadrupoles are being studied. This development has to incorporate all the relevant features for an accelerator magnet like alignment and cooling channels. The LARP HQ model is a high field and large bore quadrupole that will meet these requirements. The 2-layer coils are surrounded by a structure based on key and bladder technology with supporting iron yoke and aluminum shell. This structure is aimed at pre-stress control, alignment and field quality. We present here the magnetic and mechanical design of HQ, along with recent progress on the development of the first 1-meter model.

  13. The progenitor of SN 2011ja: Clues from circumstellar interaction

    E-Print Network [OSTI]

    Chakraborti, Sayan; Smith, Randall; Ryder, Stuart; Yadav, Naveen; Sutaria, Firoza; Dwarkadas, Vikram V; Chandra, Poonam; Pooley, David; Roy, Rupak

    2013-01-01T23:59:59.000Z

    Massive stars, possibly red supergiants, which retain extended hydrogen envelopes until the time of core collapse produce Type IIP (Plateau) supernovae. The ejecta from these explosions shock the circumstellar matter originating from the mass loss of the progenitor during the final phases of its life. This interaction accelerates particles to relativistic energies which then lose energy via synchrotron radiation in the shock-amplified magnetic fields and inverse Compton scattering against optical photons from the supernova. These processes produce different signatures in the radio and X-ray part of the electromagnetic spectrum. Observed together, they allow us to break the degeneracy between shock acceleration and magnetic field amplification. In this work we use X-rays observations from the Chandra and radio observations from the ATCA to study the relative importance of particle acceleration and magnetic fields in producing the non-thermal radiation from SN 2011ja. We use radio observations to constrain the ...

  14. A photoactive titanate with a stereochemically active Sn lone pair: Electronic and crystal structure of Sn{sub 2}TiO{sub 4} from computational chemistry

    SciTech Connect (OSTI)

    Burton, Lee A. [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath (United Kingdom)] [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath (United Kingdom); Walsh, Aron, E-mail: a.walsh@bath.ac.uk [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath (United Kingdom)] [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath (United Kingdom)

    2012-12-15T23:59:59.000Z

    TiO{sub 2} remains the most widely studied metal oxide for photocatalytic reactions. The standard approach to reduce the band gap of titania, for increasing the absorption of visible light, is anion modification. For example the formation of an oxynitride compound, where the nitrogen 2p states decrease the binding energy of the valence band. We demonstrate that cation modification can produce a similar effect through the formation of a ternary oxide combining Ti and an ns{sup 2} cation, Sn(II). In Sn{sub 2}TiO{sub 4}, the underlying Ti 3d conduction states remain largely unmodified and an electronic band gap of 2.1 eV (590 nm) is predicted by hybrid density functional theory. Our analysis indicates a strong potential for Sn{sub 2}TiO{sub 4} in visible-light driven photocatalysis, which should prove superior to the alternative (SnO{sub 2}){sub 1-x}(TiO{sub 2}){sub x} solid-solution. - Graphical abstract: Sn{sub 2}TiO{sub 4} is predicted to be a semiconductor with potential for bipolar conductivity and visible-light photocatalysis. Highlights: Black-Right-Pointing-Pointer Tin titanate adopts the Pb{sub 3}O{sub 4} crystal structure with a sterically active Sn(II) lone pair. Black-Right-Pointing-Pointer Tin titanate is thermodynamically stable with respect to TiO{sub 2} and SnO. Black-Right-Pointing-Pointer Tin titanate is predicted have a band gap of 590 nm, ideal for photocatalytic applications.

  15. Electron cooling in a young radio supernova: SN 2012aw

    SciTech Connect (OSTI)

    Yadav, Naveen; Ray, Alak [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Chakraborti, Sayan [Institute for Theory and Computation, Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Stockdale, Christopher [Marquette University, Milwaukee, WI 53233 (United States); Chandra, Poonam [National Center for Radio Astronomy-TIFR, Pune 411007 (India); Smith, Randall [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Roy, Rupak; Bose, Subhash [Aryabhhata Research Institute of Observational Sciences, Nainital 263129 (India); Dwarkadas, Vikram [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Sutaria, Firoza [Indian Institute of Astrophysics, Bangalore 560034 (India); Pooley, David, E-mail: nyadav@tifr.res.in, E-mail: akr@tifr.res.in [Department of Physics, Sam Houston State University, Huntsville, TX 77341 (United States)

    2014-02-10T23:59:59.000Z

    We present the radio observations and modeling of an optically bright Type II-P supernova (SN), SN 2012aw which exploded in the nearby galaxy Messier 95 (M95) at a distance of 10 Mpc. The spectral index values calculated using C, X, and K bands are smaller than the expected values for the optically thin regime. During this time, the optical bolometric light curve stays in the plateau phase. We interpret the low spectral-index values to be a result of electron cooling. On the basis of comparison between the Compton cooling timescale and the synchrotron cooling timescale, we find that the inverse Compton cooling process dominates over the synchrotron cooling process. We therefore model the radio emission as synchrotron emission from a relativistic electron population with a high energy cutoff. The cutoff is determined by comparing the electron cooling timescale, t {sub cool}, and the acceleration timescale, t-tilde {sub acc}. We constrain the mass-loss rate in the wind ( M-dot ?1.9×10{sup ?6} M{sub ?} yr{sup ?1}) and the equipartition factor between relativistic electrons and the magnetic field ( ?-tilde =?{sub e}/?{sub B}?1.12×10{sup 2}) through our modeling of radio emission. Although the time of explosion is fairly well constrained by optical observations within about two days, we explore the effect of varying the time of explosion to best fit the radio light curves. The best fit is obtained for the explosion date as 2012 March 15.3 UT.

  16. Low-energy electric dipole response of Sn isotopes

    E-Print Network [OSTI]

    P. Papakonstantinou; H. Hergert; V. Yu. Ponomarev; R. Roth

    2014-03-10T23:59:59.000Z

    We study the low-energy dipole (LED) strength distribution along the Sn isotopic chain in both the isoscalar (IS) and the isovector (IV, or E1) electric channels, to provide testable predictions and guidance for new experiments with stable targets and radioactive beams. We use the self-consistent Quasi-particle Random-Phase Approximation (QRPA) with finite-range interactions and mainly the Gogny D1S force. We analyze also the performance of a realistic two-body interaction supplemented by a phenomenological three-body contact term. We find that from N=50 and up to the N=82 shell closure (132Sn) the lowest-energy part of the IS-LED spectrum is dominated by a collective transition whose properties vary smoothly with neutron number and which cannot be interpreted as a neutron-skin oscillation. For the neutron-rich species this state contributes to the E1 strength below particle threshold, but much more E1 strength is carried by other, weak but numerous transitions around or above threshold. We find that strong structural changes in the spectrum take effect beyond N=82, namely increased LED strength and lower excitation energies. Our results with the Gogny interaction are compatible with existing data. On this basis we predict that a) the summed IS strength below particle threshold shall be of the same order of magnitude for N=50-82, b) the summed E1 strength up to approximately 12 MeV shall be similar for N=50-82 MeV, while c) the summed E1 strength below threshold shall be of the same order of magnitude for N ~ 64 - 82 and much weaker for the lighter, more-symmetric isotopes. We point out a general agreement of our results with other non-relativistic studies, the absence of a collective IS mode in some of those studies, and a possibly radical disagreement with relativistic models.

  17. Liquid immiscibility and core-shell morphology formation in ternary Al–Bi–Sn alloys

    SciTech Connect (OSTI)

    Dai, R.; Zhang, J.F.; Zhang, S.G., E-mail: sgzhang@sjtu.edu.cn; Li, J.G.

    2013-07-15T23:59:59.000Z

    The effects of composition on liquid immiscibility, macroscopic morphology, microstructure and phase transformation in ternary Al–Bi–Sn alloys were investigated. Three types of morphology, the core-shell type, the stochastic droplet type and uniform dispersion type, of Al–Bi–Sn particles prepared by a jet breakup process were distinguished, and the relationships between which were discussed. The phase transformation behaviors of the Al–Bi–Sn alloys were studied by thermal analysis, in agreement with the microstructural observation and microanalysis. The liquid immiscibility and formation of the core-shell morphology in Al–Bi–Sn alloys are easily achieved when the composition lies in the liquid miscibility gap. The particles exhibit a high melting point Al-rich core with a low melting point Sn–Bi-rich solder shell, showing promise for application as high-density electronic packaging materials. - Highlights: • The liquid demixing, morphology and microstructure in Al–Bi–Sn alloys were studied. • Three types of morphology were classified and discussed. • The conditions for formation of the core-shell morphology were obtained. • The phase transition behaviors agree with the microstructure characterization. • The Al/Sn–Bi core-shell particles show promise for use in electronic packaging.

  18. Synthesis and Structure Determination of Ferromagnetic Semiconductors LaAMnSnO6 (A = Sr Ba)

    SciTech Connect (OSTI)

    T Yang; T Perkisas; J Hadermann; M Croft; A Ignatov; M Greenblatt

    2011-12-31T23:59:59.000Z

    LaAMnSnO{sub 6} (A = Sr, Ba) have been synthesized by high temperature solid-state reactions under dynamic 1% H{sub 2}/Ar flow. Rietveld refinements on room temperature powder X-ray diffraction data indicate that LaSrMnSnO{sub 6} crystallizes in the GdFeO{sub 3}-structure, with space group Pnma and, combined with transmission electron microscopy, LaBaMnSnO{sub 6} in Imma. Both space groups are common in disordered double-perovskites. The Mn{sup 3+} and Sn{sup 4+} ions whose valence states were confirmed by X-ray absorption spectroscopy, are completely disordered over the B-sites and the BO{sub 6} octahedra are slightly distorted. LaAMnSnO{sub 6} are ferromagnetic semiconductors with a T{sub C} = 83 K for the Sr- and 66 K for the Ba-compound. The title compounds, together with the previously reported LaCaMnSnO{sub 6} provide an interesting example of progression from Pnma to Imma as the tolerance factor increases. An analysis of the relationship between space group and tolerance factor for the series LaAMnMO{sub 6} (A = Ca, Sr, Ba; M = Sn, Ru) provides a better understanding of the symmetry determination for double perovskites.

  19. A Neutron Star-driven XRF associated with SN 2006aj

    E-Print Network [OSTI]

    Mazzali, P A; Maeda, K; Nomoto, K; Pian, E; Tanaka, M; Tominaga, N; Deng, Jinsong; Maeda, Keiichi; Mazzali, Paolo A.; Nomoto, Ken'ichi; Pian, Elena; Tanaka, Masaomi; Tominaga, Nozomu

    2006-01-01T23:59:59.000Z

    Observations and models of SN 2006aj, while bringing fresh evidence of the connection between long Gamma Ray Bursts (GRBs) and Supernovae (SNe), suggest that there is variety among these events. The previously well observed cases (GRB980425/SN 1998bw, GRB030329/SN 2003dh, GRB031203/SN 2003lw) could be explained as the prompt collapse to a black hole of the core of a massive star (M ~ 40 Msun) that had lost its outer hydrogen and helium envelopes. All these SNe exhibited strong oxygen lines, thus being classified as Type Ic, and their energies were much larger than those of typical SNe. The case of SN 2006aj/GRB060218 appears different: the GRB was weak and soft (an X-Ray Flash, XRF); the SN is dimmer and has very weak oxygen lines, suggesting a "Type Ic/d" classification. The explosion energy of SN 2006aj was smaller, as was the ejected mass. In our model, the progenitor star had a smaller mass than other GRB/SNe (M ~ 20 Msun), suggesting that a neutron star rather than a black hole was formed. If the nascent...

  20. Structural and optical properties of GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells

    SciTech Connect (OSTI)

    Aleshkin, V. Ya.; Dubinov, A. A., E-mail: sanya@ipm.sci-nnov.ru; Drozdov, M. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Zvonkov, B. N. [Nizhni Novgorod State University, Research Physical Technical Institute (Russian Federation); Kudryavtsev, K. E.; Tonkikh, A. A.; Yablonskiy, A. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Werner, P. [Max Planck Institute of Microstructure Physics (Germany)

    2013-05-15T23:59:59.000Z

    GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells are grown by laser-assisted sputtering. Structural and optical studies of the heterostructures are carried out. A broad photoluminescence line is observed in the wavelength range from 1300 to 1650 nm. The line corresponds to indirect transitions in the momentum space of the Ge quantum wells and to transitions between the In{sub 0.28}Ga{sub 0.72}As and Ge layers, indirect in coordinate space, but direct in momentum space.

  1. Serial and parallel Si, Ge, and SiGe direct-write with scanning probes and conducting stamps

    SciTech Connect (OSTI)

    Vasko, Stephanie E.; Kapetanovic, Adnan; Talla, Vamsi; Brasino, Michael D.; Zhu, Zihua; Scholl, Andreas; Torrey, Jessica D.; Rolandi, Marco

    2011-05-16T23:59:59.000Z

    Precise materials integration in nanostructures is fundamental for future electronic and photonic devices. We demonstrate Si, Ge, and SiGe nanostructure direct-write with deterministic size, geometry, and placement control. The biased probe of an atomic force microscope (AFM) reacts diphenylsilane or diphenylgermane to direct-write carbon-free Si, Ge, and SiGe nano and heterostructures. Parallel directwrite is available on large areas by substituting the AFM probe with conducting microstructured stamps. This facile strategy can be easily expanded to a broad variety of semiconductor materials through precursor selection.

  2. SN 2012au: A GOLDEN LINK BETWEEN SUPERLUMINOUS SUPERNOVAE AND THEIR LOWER-LUMINOSITY COUNTERPARTS

    SciTech Connect (OSTI)

    Milisavljevic, Dan; Soderberg, Alicia M.; Margutti, Raffaella; Drout, Maria R.; Marion, G. Howie; Sanders, Nathan E.; Lunnan, Ragnhild; Chornock, Ryan; Berger, Edo; Foley, Ryan J.; Challis, Pete; Kirshner, Robert P.; Dittmann, Jason; Bieryla, Allyson; Kamble, Atish; Chakraborti, Sayan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Hsiao, Eric Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Fesen, Robert A.; Parrent, Jerod T. [6127 Wilder Lab, Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Levesque, Emily M., E-mail: dmilisav@cfa.harvard.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); and others

    2013-06-20T23:59:59.000Z

    We present optical and near-infrared observations of SN 2012au, a slow-evolving supernova (SN) with properties that suggest a link between subsets of energetic and H-poor SNe and superluminous SNe. SN 2012au exhibited conspicuous Type-Ib-like He I lines and other absorption features at velocities reaching Almost-Equal-To 2 Multiplication-Sign 10{sup 4} km s{sup -1} in its early spectra, and a broad light curve that peaked at M{sub B} = -18.1 mag. Models of these data indicate a large explosion kinetic energy of {approx}10{sup 52} erg and {sup 56}Ni mass ejection of M{sub Ni} Almost-Equal-To 0.3 M{sub Sun} on par with SN 1998bw. SN 2012au's spectra almost one year after explosion show a blend of persistent Fe II P-Cyg absorptions and nebular emissions originating from two distinct velocity regions. These late-time emissions include strong [Fe II], [Ca II], [O I], Mg I], and Na I lines at velocities {approx}> 4500 km s{sup -1}, as well as O I and Mg I lines at noticeably smaller velocities {approx}< 2000 km s{sup -1}. Many of the late-time properties of SN 2012au are similar to the slow-evolving hypernovae SN 1997dq and SN 1997ef, and the superluminous SN 2007bi. Our observations suggest that a single explosion mechanism may unify all of these events that span -21 {approx}< M{sub B} {approx}< -17 mag. The aspherical and possibly jetted explosion was most likely initiated by the core collapse of a massive progenitor star and created substantial high-density, low-velocity Ni-rich material.

  3. Predicting the amount of hydrogen stripped by the SN explosion for SN 2002cx-like SNe Ia

    SciTech Connect (OSTI)

    Liu, Zheng-Wei; Chen, X. F.; Wang, B.; Han, Z. W. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Kromer, M. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching (Germany); Fink, M.; Röpke, F. K. [Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany); Pakmor, R., E-mail: zwliu@ynao.ac.cn [Heidelberger Institut für Theoretische Studien, Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg (Germany)

    2013-12-01T23:59:59.000Z

    The most favored progenitor scenarios for Type Ia supernovae (SNe Ia) involve the single-degenerate (SD) scenario and the double-degenerate scenario. The absence of stripped hydrogen (H) in the nebular spectra of SNe Ia challenges the SD progenitor models. Recently, it was shown that pure deflagration explosion models of Chandrasekhar-mass white dwarfs, ignited off-center, reproduce the characteristic observational features of 2002cx-like SNe Ia very well. In this work we predict, for the first time, the amount of stripped H for the off-center, pure deflagration explosions. We find that their low kinetic energies lead to inefficient H mass stripping (? 0.01 M {sub ?}), indicating that the stripped H may be hidden in (observed) late-time spectra of SN 2002cx-like SNe Ia.

  4. Theoretical Studies of Rare-Earth Nuclei leading to $_{50}$Sn-Daughter Products and the Associated Shell Effects

    E-Print Network [OSTI]

    Sushil Kumar

    2012-05-26T23:59:59.000Z

    Cluster decays of rare-earth nuclei are studied with a view to look for neutron magic shells for the $_{50}$Sn nucleus as the daughter product always. The $^{100}$Sn and $^{132}$Sn radioactivities are studied to find the most probable cluster decays and the possibility, if any, of new neutron shells. For a wide range of parent nuclei considered here (from Ba to Pt) $^{12}$C from $^{112}$Ba and $^{78}$Ni from $^{210}$Pt parent are predicted to be the most probable clusters (minimum decay half-life) referring to $^{100}$Sn and $^{132}$Sn daughters, respectively. Also, $^{22}$Mg decay of $^{122}$Sm is indicated at the second best possibilty for $^{100}$Sn-daughter decay. In addition to these well known magic shells (Z=50, N=50 and 82), a new magic shell at Z=50, N=66 ($^{116}$Sn daughter) is indicated for the $^{64}$Ni decay from $^{180}$Pt parent.

  5. Hydrothermal synthesis of flowerlike SnO{sub 2} nanorod bundles and their application for lithium ion battery

    SciTech Connect (OSTI)

    Wen, Zhigang, E-mail: xh168688@126.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Department of Chemistry and Chemical Engineering, Qiannan Normal College for Nationalities, Duyun 558000 (China); Zheng, Feng, E-mail: fzheng@mail.csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Yu, Hongchun; Jiang, Ziran [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Liu, Kanglian [Department of Chemistry and Chemical Engineering, Qiannan Normal College for Nationalities, Duyun 558000 (China)

    2013-02-15T23:59:59.000Z

    SnO{sub 2} nanorod bundles were synthesized by hydrothermal method. Field-emission scanning electron microscopy and transmission electron microscopy images showed that the as-prepared flowerlike SnO{sub 2} nanorod bundles consist of tetragonal nanorods with size readily tunable. Their electrochemical properties and application as anode for lithium-ion battery were evaluated by galvanostatic discharge–charge testing and cycle voltammetry. SnO{sub 2} nanorod flowers possess improved discharge capacity of 694 mA h g{sup ?1} up to 40th cycle at 0.1 C. - Highlights: ? The flowerlike SnO{sub 2} nanorod bundles were synthesized by hydrothermal method. ? SnO{sub 2} nanorod bundles with tunable size by controlling concentration of SnCl{sub 4}. ? A probable formation mechanism of SnO{sub 2} nanorod bundles has been proposed.

  6. Mildly relativistic X-ray transient 080109 and SN2008D: Towards a continuum from energetic GRB/XRF to ordinary Ibc SN

    E-Print Network [OSTI]

    Xu, Dong; Fan, Yi-Zhong

    2008-01-01T23:59:59.000Z

    We analyze the hitherto available space-based X-ray data as well as ground-based optical data of the X-ray transient 080109/SN2008D. From the data we suggest that (i) The initial transient (\\lesssim 800 sec) is attributed to the reverse shock emission of a mildly relativistic (\\Gamma \\sim a few) outflow stalled by the dense stellar wind. (ii) The subsequent X-ray afterglow (\\lesssim 2\\times 10^4 sec) can be ascribed to the forward shock emission of the outflow, with a kinetic energy \\sim 10^{46} erg, when sweeping up the stellar wind medium. (iii) The late X-ray flattening (\\gtrsim 2\\times 10^4$ sec) is powered by the fastest non-decelerated component of SN2008D's ejecta. (iv) The local event rate of X-ray transient has a lower limit of \\sim 1.6\\times 10^4 yr^{-1} Gpc^{-3}, indicating a vast majority of X-ray transients have a wide opening angle of \\gtrsim 100 degree. The off-axis viewing model is less likely. (v) Transient 080109/SN2008D may lead to a continuum from GRB-SN to under-luminous GRB-/XRF-SN to X-...

  7. Shell model description of Ge isotopes

    E-Print Network [OSTI]

    J. G. Hirsch; P. C. Srivastava

    2012-04-12T23:59:59.000Z

    A shell model study of the low energy region of the spectra in Ge isotopes for $38\\leq N\\leq 50$ is presented, analyzing the excitation energies, quadrupole moments, $B(E2)$ values and occupation numbers. The theoretical results have been compared with the available experimental data. The shell model calculations have been performed employing three different effective interactions and valence spaces.We have used two effective shell model interactions, JUN45 and jj44b, for the valence space $f_{5/2} \\, p \\,g_{9/2}$ without truncation. To include the proton subshell $f_{7/2}$ in valence space we have employed the $fpg$ effective interaction due to Sorlin {\\it et al.}, with $^{48}$Ca as a core and a truncation in the number of excited particles.

  8. 3 GeV Injector Design Handbook

    SciTech Connect (OSTI)

    Wiedemann, H.; /SLAC, SSRL

    2009-12-16T23:59:59.000Z

    This Design Handbook is intended to be the main reference book for the specifications of the 3 GeV SPEAR booster synchrotron project. It is intended to be a consistent description of the project including design criteria, key technical specifications as well as current design approaches. Since a project is not complete till it's complete changes and modifications of early conceptual designs must be expected during the duration of the construction. Therefore, this Design Handbook is issued as a loose leaf binder so that individual sections can be replaced as needed. Each page will be dated to ease identification with respect to latest revisions. At the end of the project this Design Handbook will have become the 'as built' reference book of the injector for operations and maintenance personnel.

  9. Nanostructure and infrared photoluminescence of nanocrystalline Ge formed by reduction of Si0.75Ge0.25O2 Si0.75Ge0.25 using various H2 pressures

    E-Print Network [OSTI]

    Nanostructure and infrared photoluminescence of nanocrystalline Ge formed by reduction of Si0.75Ge0.25O2 ÕSi0.75Ge0.25 using various H2 pressures Gianni Taraschi,a) Sajan Saini, Wendy W. Fan, Lionel C Ge in SiO2 was synthesized by the reduction of Si0.75Ge0.25O2 with H2 , at various annealing

  10. High Capacity Li Ion Battery Anodes Using Ge Nanowires

    E-Print Network [OSTI]

    Cui, Yi

    High Capacity Li Ion Battery Anodes Using Ge Nanowires Candace K. Chan, Xiao Feng Zhang, and Yi Cui efficiency > 99%. Structural characterization revealed that the Ge nanowires remain intact and connected nanowire anodes are promising candidates for the development of high-energy-density lithium batteries

  11. Project-X Workshop 120 GeV Target

    E-Print Network [OSTI]

    McDonald, Kirk

    Project-X Workshop 120 GeV Target Summary ­ Workshop # 1 N. Simos, M. Martens #12;Project-X Workshop Challenges OVERVIEW Driven by 120 GeV/170 TP-per-spill · Short Term: 170 TPs/2us-spill (materials an existing 400 kW facility ­ Constraints #12;Project-X Workshop Presentations - Discussions · Engineering

  12. Band-engineered Ge-on-Si lasers

    E-Print Network [OSTI]

    Liu, Jifeng

    We report optically-pumped Ge-on-Si lasers with direct gap emission near 1600 nm at room temperature. The Ge-on-Si material was band-engineered by tensile strain and n-type doping to compensate the energy difference between ...

  13. Excess vacancies in high energy ion implanted SiGe

    SciTech Connect (OSTI)

    Koegler, R.; Muecklich, A.; Skorupa, W.; Peeva, A.; Kuznetsov, A. Yu.; Christensen, J. S.; Svensson, B. G. [Forschungszentrum Rossendorf, PF 510119, D-01314 Dresden (Germany); Institute of Solid State Physics BAS, Boulevard Tzarigradsko Chaussee 72, 1784 Sofia (Bulgaria); Deparment of Physics, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo (Norway); Center for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo (Norway)

    2007-02-01T23:59:59.000Z

    Excess vacancies generated by high energy implantation with 1.2 MeV Si{sup +} and 2 MeV Ge{sup +} ions in SiGe were investigated after rapid thermal annealing at 900 degree sign C. Excess vacancies were probed by decoration with Cu and measuring the Cu profile by secondary ion mass spectrometry. Cross section transmission electron microscopy of cleaved specimen enabled to visualize nanocavities resulting from agglomeration of excess vacancies. The ion-induced damage in SiGe increases with increasing Ge fraction of the alloy. The amorphization threshold decreases and the extension of a buried amorphous layer increases for given implantation and annealing conditions. In contrast to ballistic simulations of excess defect generation where perfect local self-annihilation is assumed the concentrations of excess vacancies and excess interstitials in SiGe increase with increasing Ge fraction. The main contribution to the high excess vacancy concentration in SiGe results from the inefficient recombination of vacancies and interstitials. The widely used +1 model describing the ion-induced damage in Si is not valid for SiGe.

  14. Volcanic rifting at Martian grabens Daniel Me`ge,1

    E-Print Network [OSTI]

    Mege, Daniel

    Volcanic rifting at Martian grabens Daniel Me`ge,1 Anthony C. Cook,2,3 Erwan Garel,4 Yves: Solar System Objects: Mars; 8121 Tectonophysics: Dynamics, convection currents and mantle plumes; 8010: Me`ge, D., A. C. Cook, E. Garel, Y. Lagabrielle, and M.-H. Cormier, Volcanic rifting at Martian

  15. Excess carrier lifetimes in Ge layers on Si

    SciTech Connect (OSTI)

    Geiger, R., E-mail: richard.geiger@psi.ch, E-mail: hans.sigg@psi.ch; Sigg, H., E-mail: richard.geiger@psi.ch, E-mail: hans.sigg@psi.ch [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Frigerio, J.; Chrastina, D.; Isella, G. [L-NESS, Dipartimento di Fisica del Politecnico di Milano, Via Anzani 42, 22100 Como (Italy); Süess, M. J. [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Laboratory for Nanometallurgy, Department of Materials Science, ETH Zurich, 8093 Zurich (Switzerland); Scientific Center for Optical and Electron Microscopy (SCOPEM), ETH Zurich, 8093 Zurich (Switzerland); Spolenak, R. [Laboratory for Nanometallurgy, Department of Materials Science, ETH Zurich, 8093 Zurich (Switzerland); Faist, J. [Institute for Quantum Electronics, ETH Zurich, 8093 Zurich (Switzerland)

    2014-02-10T23:59:59.000Z

    The excess charge carrier lifetimes in Ge layers grown on Si or germanium-on-insulator are measured by synchrotron based pump-probe transmission spectroscopy. We observe that the lifetimes do not strongly depend on growth parameters and annealing procedure, but on the doping profile. The defect layer at the Ge/Si interface is found to be the main non-radiative recombination channel. Therefore, the longest lifetimes in Ge/Si (2.6?ns) are achieved in sufficiently thick Ge layers with a built-in field, which repels electrons from the Ge/Si interface. Longer lifetimes (5.3?ns) are obtained in overgrown germanium-on-insulator due to the absence of the defective interface.

  16. Structural phase transitions on the nanoscale: The crucial pattern in the phase-change materials Ge2Sb2Te5 and GeTe

    E-Print Network [OSTI]

    Structural phase transitions on the nanoscale: The crucial pattern in the phase-change materials Ge2Sb2Te5 and GeTe J. Akola1,2 and R. O. Jones1 1Institut für Festkörperforschung, Forschungszentrum to characterize the amorphous structure of the prototype materials Ge2Sb2Te5 and GeTe. In both, there is long

  17. III International Conference on SiGe(C) Epitaxy and Heterostructures, NM, Mar. 2003 SiGe Single-Hole Transistor Fabricated by AFM Oxidation and Epitaxial Regrowth

    E-Print Network [OSTI]

    III International Conference on SiGe(C) Epitaxy and Heterostructures, NM, Mar. 2003 110 SiGe Single, West Lafayette, IN 47907, U.S.A. Nanodevices on Si/SiGe heterostructures are of growing interest [1 the performance of the devices. In this paper, we demonstrate a reproducible single-hole transistor SiGe device

  18. The role of straining and morphology in thermal conductivity of a set of SiGe superlattices and biomimetic SiGe nanocomposites

    E-Print Network [OSTI]

    Tomar, Vikas

    The role of straining and morphology in thermal conductivity of a set of Si­Ge superlattices and biomimetic Si­Ge nanocomposites This article has been downloaded from IOPscience. Please scroll down to see and morphology in thermal conductivity of a set of Si­Ge superlattices and biomimetic Si­Ge nanocomposites Vikas

  19. On atomic structure of Ge huts growing on the Ge/Si(001) wetting layer

    SciTech Connect (OSTI)

    Arapkina, Larisa V.; Yuryev, Vladimir A. [A. M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov Street, Moscow, 119991 (Russian Federation)] [A. M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov Street, Moscow, 119991 (Russian Federation)

    2013-09-14T23:59:59.000Z

    Structural models of growing Ge hut clusters—pyramids and wedges—are proposed on the basis of data of recent STM investigations of nucleation and growth of Ge huts on the Si(001) surface in the process of molecular beam epitaxy. It is shown that extension of a hut base along <110> directions goes non-uniformly during the cluster growth regardless of its shape. Growing pyramids, starting from the second monolayer, pass through cyclic formation of slightly asymmetrical and symmetrical clusters, with symmetrical ones appearing after addition of every fourth monolayer. We suppose that pyramids of symmetrical configurations composed by 2, 6, 10, etc., monolayers over the wetting layer are more stable than asymmetrical ones. This might explain less stability of pyramids in comparison with wedges in dense arrays forming at low temperatures of Ge deposition. Possible nucleation processes of pyramids and wedges on wetting layer patches from identical embryos composed by 8 dimers through formation of 1 monolayer high 16-dimer nuclei different only in their symmetry is discussed. Schematics of these processes are presented. It is concluded from precise STM measurements that top layers of wetting layer patches are relaxed when huts nucleate on them.

  20. Z=50 shell gap near $^{100}$Sn from intermediate-energy Coulomb excitations in even-mass $^{106--112}$Sn isotopes

    E-Print Network [OSTI]

    C. Vaman; C. Andreoiu; D. Bazin; A. Becerril; A. Brown; C. M. Campbell; A. Chester; J. M. Cook; D. C. Dinca; A. Gade; D. Galaviz; T. Glasmacher; M. Hjorth-Jensen; M. Horoi; D. Miller; V. Moeller; W. F. Mueller; A. Schiller; K. Starosta; A. Stolz; J. R. Terry; A. Volya; V. Zelevinsky; H. Zwahlen

    2006-12-08T23:59:59.000Z

    Rare isotope beams of neutron-deficient $^{106,108,110}$Sn nuclei from the fragmentation of $^{124}$Xe were employed in an intermediate-energy Coulomb excitation experiment yielding $B(E2, 0^+_1 \\to 2^+_1)$ transition strengths. The results indicate that these $B(E2,0^+_1 \\to 2^+_1)$ values are much larger than predicted by current state-of-the-art shell model calculations. This discrepancy can be explained if protons from within the Z = 50 shell are contributing to the structure of low-energy excited states in this region. Such contributions imply a breaking of the doubly-magic $^{100}$Sn core in the light Sn isotopes.

  1. Microstructure and Sn crystal orientation evolution in Sn-3.5Ag lead-free solders in high temperature packaging applications

    SciTech Connect (OSTI)

    Zhou, Bite [ORNL; Muralidharan, Govindarajan [ORNL; Kurumaddali, Nalini Kanth [ORNL; Parish, Chad M [ORNL; Leslie, Dr Scott [Powerex Inc; Bieler, T. R. [Michigan State University, East Lansing

    2014-01-01T23:59:59.000Z

    Understanding the reliability of eutectic Sn-3.5Ag lead-free solders in high temperature packaging applications is of significant interest in power electronics for the next generation electric grid. Large area (2.5mm 2.5mm) Sn-3.5Ag solder joints between silicon dies and direct bonded copper substrates were thermally cycled between 5 C and 200 C. Sn crystal orientation and microstructure evolution during thermal cycling were characterized by electron backscatter diffraction (EBSD) in scanning electron microscope (SEM). Comparisons are made between observed initial texture and microstructure and its evolution during thermal cycling. Gradual lattice rotation and grain boundary misorientation evolution suggested the continuous recrystallization mechanism. Recrystallization behavior was correlated with dislocation slip activities.

  2. Development of Nb{sub 3}Sn Cavity Vapor Diffusion Deposition System

    SciTech Connect (OSTI)

    Eremeev, Grigory V.; Macha, Kurt M.; Clemens, William A.; Park, HyeKyoung; Williams, R. Scott

    2014-02-01T23:59:59.000Z

    Nb{sub 3}Sn is a BCS superconductors with the superconducting critical temperature higher than that of niobium, so theoretically it surpasses the limitations of niobium in RF fields. The feasibility of technology has been demonstrated at 1.5 GHz with Nb{sub 3}Sn vapor deposition technique at Wuppertal University. The benefit at these frequencies is more pronounced at 4.2 K, where Nb{sub 3}Sn coated cavities show RF resistances an order of magnitude lower than that of niobium. At Jefferson Lab we started the development of Nb{sub 3}Sn vapor diffusion deposition system within an R\\&D development program towards compact light sources. Here we present the current progress of the system development.

  3. SnO2 Nanoribbons as NO2 Sensors: Insights from First Principles

    E-Print Network [OSTI]

    Yang, Peidong

    -doped semiconductor with the intrinsic carrier density determined by the deviation from stoichiometry, primarily neighbors, and each O atom is a 3-fold bridge between neighboring Sn centers. At both the (1 0 1h) and (0 1

  4. Molecular Mimicry Regulates ABA Signaling by SnRK2 Kinases and PP2C Phosphatases

    SciTech Connect (OSTI)

    Soon, Fen-Fen; Ng, Ley-Moy; Zhou, X. Edward; West, Graham M.; Kovach, Amanda; Tan, M.H. Eileen; Suino-Powell, Kelly M.; He, Yuanzheng; Xu, Yong; Chalmers, Michael J.; Brunzelle, Joseph S.; Zhang, Huiming; Yang, Huaiyu; Jiang, Hualiang; Li, Jun; Yong, Eu-Leong; Cutler, Sean; Zhu, Jian-Kang; Griffin, Patrick R.; Melcher, Karsten; Xu, H. Eric (Van Andel); (Scripps); (NWU); (Purdue); (UCR); (Chinese Aca. Sci.); (NU Singapore)

    2014-10-02T23:59:59.000Z

    Abscisic acid (ABA) is an essential hormone for plants to survive environmental stresses. At the center of the ABA signaling network is a subfamily of type 2C protein phosphatases (PP2Cs), which form exclusive interactions with ABA receptors and subfamily 2 Snfl-related kinase (SnRK2s). Here, we report a SnRK2-PP2C complex structure, which reveals marked similarity in PP2C recognition by SnRK2 and ABA receptors. In the complex, the kinase activation loop docks into the active site of PP2C, while the conserved ABA-sensing tryptophan of PP2C inserts into the kinase catalytic cleft, thus mimicking receptor-PP2C interactions. These structural results provide a simple mechanism that directly couples ABA binding to SnRK2 kinase activation and highlight a new paradigm of kinase-phosphatase regulation through mutual packing of their catalytic sites.

  5. Radiopharmaceutical stannic Sn-117m chelate compositions and methods of use

    DOE Patents [OSTI]

    Srivastava, Suresh C. (Setauket, NY); Meinken, George E. (Middle Island, NY)

    2001-01-01T23:59:59.000Z

    Radiopharmaceutical compositions including .sup.117m Sn labeled stannic (Sn.sup.4+) chelates are provided. The chelates are preferably polyhydroxycarboxylate, such as oxalates, tartrates, citrates, malonates, gluconates, glucoheptonates and the like. Methods of making .sup.117m Sn-labeled (Sn.sup.4+) polyhydroxycarboxylic chelates are also provided. The foregoing pharmaceutical compositions can be used in methods of preparing bone for scintigraphical analysis, for radiopharmaceutical skeletal imaging, treatment of pain resulting from metastatic bone involvement, treatment of primary bone cancer, treatment of cancer resulting from metastatic spread to bone from other primary cancers, treatment of pain resulting from rheumatoid arthritis, treatment of bone/joint disorders and to monitor radioactively the skeletal system.

  6. A New Mathematical Adjoint for the Modified SAAF-SN Equations

    SciTech Connect (OSTI)

    Schunert, Sebastian (090720); Wang, Yaqi (090690); Martineau, Richard C (062281)

    2015-01-01T23:59:59.000Z

    We present a new adjoint FEM weak form, which can be directly used for evaluating the mathematical adjoint, suitable for perturbation calculations, of the self-adjoint angular flux SN equations (SAAF-SN) without construction and transposition of the underlying coecient matrix. Stabilization schemes incorporated in the described SAAF-SN method make the mathematical adjoint distinct from the physical adjoint, i.e. the solution of the continuous adjoint equation with SAAF-SN . This weak form is implemented into RattleSnake, the MOOSE (Multiphysics Object-Oriented Simulation Environment) based transport solver. Numerical results verify the correctness of the implementation and show its utility both for fixed source and eigenvalue problems.

  7. Dynamical deformation effects in subbarrier fusion of $^{64}$Ni+$^{132}$Sn

    E-Print Network [OSTI]

    A. S. Umar; V. E. Oberacker

    2006-09-25T23:59:59.000Z

    We show that dynamical deformation effects play an important role in fusion reactions involving the $^{64}$Ni nucleus, in particular the $^{64}$Ni+$^{132}$Sn system. We calculate fully microscopic interaction potentials and the corresponding subbarrier fusion cross sections.

  8. Controlling SEI Formation on SnSb-Porous Carbon Nanofibers for...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for Improved Na Ion Storage. Abstract: Porous carbon nanofiber (CNF)-supported tin-antimony (SnSb) alloys is synthesized and applied as sodium ion battery anode. The...

  9. aperture nb3sn racetrack: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    D; Velev, G 2013-01-01 5 Fabrication and test results of a high field, Nb3Sn superconducting racetrack dipole magnet University of California eScholarship Repository Summary:...

  10. Ratio of jet cross sections at root s=630 GeV and 1800 GeV

    E-Print Network [OSTI]

    Baringer, Philip S.; Bean, Alice; Coppage, Don; Hebert, C.

    2001-03-01T23:59:59.000Z

    The DO Collaboration has measured the inclusive jet cross section in (p) over barp collisions at roots = 630 GeV. The results for pseudorapidities \\ eta \\ < 0.5 are combined with our previous results at roots = 1800 GeV ...

  11. Synthesis, structure, and bonding in K12Au21Sn4. A polar intermetallic compound with dense Au20 and open AuSn4 layers

    SciTech Connect (OSTI)

    Li, Bin; Kim, Sung-Jin; Miller, Gordon J.; and Corbett, John D.

    2009-10-29T23:59:59.000Z

    The new phase K{sub 12}Au{sub 21}Sn{sub 4} has been synthesized by direct reaction of the elements at elevated temperatures. Single crystal X-ray diffraction established its orthorhombic structure, space group Pmmn (No. 59), a = 12.162(2); b = 18.058(4); c = 8.657(2) {angstrom}, V = 1901.3(7) {angstrom}{sup 3}, and Z = 2. The structure consists of infinite puckered sheets of vertex-sharing gold tetrahedra (Au{sub 20}) that are tied together by thin layers of alternating four-bonded-Sn and -Au atoms (AuSn{sub 4}). Remarkably, the dense but electron-poorer blocks of Au tetrahedra coexist with more open and saturated Au-Sn layers, which are fragments of a zinc blende type structure that maximize tetrahedral heteroatomic bonding outside of the network of gold tetrahedra. LMTO band structure calculations reveal metallic properties and a pseudogap at 256 valence electrons per formula unit, only three electrons fewer than in the title compound and at a point at which strong Au-Sn bonding is optimized. Additionally, the tight coordination of the Au framework atoms by K plays an important bonding role: each Au tetrahedra has 10 K neighbors and each K atom has 8-12 Au contacts. The appreciably different role of the p element Sn in this structure from that in the triel members in K{sub 3}Au{sub 5}In and Rb{sub 2}Au{sub 3}Tl appears to arise from its higher electron count which leads to better p-bonding (valence electron concentrations = 1.32 versus 1.22).

  12. Optical and electrochemical studies of polyaniline/SnO{sub 2} fibrous nanocomposites

    SciTech Connect (OSTI)

    Manivel, P. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046, Tamil Nadu (India)] [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046, Tamil Nadu (India); Ramakrishnan, S.; Kothurkar, Nikhil K. [Department of Chemical Engineering and Material Science, Amrita Vishwa Vidyapeetham, Coimbatore 641 112, Tamil Nadu (India)] [Department of Chemical Engineering and Material Science, Amrita Vishwa Vidyapeetham, Coimbatore 641 112, Tamil Nadu (India); Balamurugan, A.; Ponpandian, N.; Mangalaraj, D. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046, Tamil Nadu (India)] [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046, Tamil Nadu (India); Viswanathan, C., E-mail: viswanathan@buc.edu.in [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046, Tamil Nadu (India)

    2013-02-15T23:59:59.000Z

    Graphical abstract: Fiber with porous like structure of PANI/SnO{sub 2} nanocomposites were prepared by simplest in situ chemical polymerization method. The PL emission spectra revealed that the band from 404 and 436 nm which is related with oxygen vacancies. The excellent electrochemical properties of composite electrode show the specific capacitance of 173 F/g at a scan rate of 25 m V/s. Display Omitted Highlights: ? Self assembled PANI/SnO{sub 2} nanocomposites were synthesized by simple polymerization method. ? Electrochemical behavior of PANI/SnO{sub 2} nanocomposites electrode was analyzed by CV. ? Nanocomposites exhibit a higher specific capacitance of 173 F/g, compared with pure SnO{sub 2}. -- Abstract: Polyaniline (PANI)/tin oxide (SnO{sub 2}) fibrous nanocomposites were successfully prepared by an in situ chemical polymerization method with suitable conditions. The obtained composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, photoluminescence (PL), electrical conductivity and cyclic voltammetry studies (CV). The XRD pattern of the as-prepared sample shows the presence of tetragonal SnO{sub 2} and the crystalline structure of SnO{sub 2} was not affected with the incorporation of PANI. The FTIR analysis confirms the uniform attachment of PANI on the surface of SnO{sub 2} nanostructures. SEM images show a fibrous agglomerated structure of PANI/SnO{sub 2}. The PL emission spectra revealed that the band from 404 and 436 nm which is related with oxygen vacancies. The electrochemical behavior of the PANI/SnO{sub 2} composite electrode was evaluated in a H{sub 2}SO{sub 4} solution using cyclic voltammetry. The composite electrode exhibited a specific capacitance of 173 F/g at a scan rate 25 mV/s. Thus the as-prepared PANI/SnO{sub 2} composite shows excellent electrochemical properties, suggesting that this composite is a promising material for supercapacitors.

  13. Ion Implanted Ge:B Far Infrard Blocked Impurity Band Detectors

    E-Print Network [OSTI]

    Beeman, J.W.; Goyal, S.; Reichertz, L.A.; Haller, E.E.

    2008-01-01T23:59:59.000Z

    +16 1.E+15 1.E+14 Depth into Ge Crystal Surface (Å) Figure 5devices does not match that of Ge:Ga photoconductors, whichimplants or stacking devices) Ge IBIB detectors will reach

  14. ALFVEN-WAVE OSCILLATIONS IN A SPHERE, WITH APPLICATIONS TO ELECTRON-HOLE DROPS IN Ge

    E-Print Network [OSTI]

    Markiewicz, R.S.

    2011-01-01T23:59:59.000Z

    Rev. B 13,4626 (1976). For Ge(4:2) m is the average of thediscussed for EHD in unstressed Ge (B II )TO ELECI'RON-OOLE DROPS IN Ge R. S. Markiewicz January 1978

  15. NUCLEATION PHENOMENA IN THE FORMATION OF ELECTRON-HOLE DROPS IN Ge

    E-Print Network [OSTI]

    Westervelt, R.M.

    2010-01-01T23:59:59.000Z

    lO cjl(K) Symbol erg cm ) Ge - 0.064 T2 Ref. x x Si Ref. T2constructed the ultra-sensitive Ge photodetector which wasand method of mounting. The Ge sample is electrically and

  16. Photo-oxidation of Ge Nanocrystals: Kinetic Measurements by In Situ Raman Spectroscopy

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    Photo-oxidation of Ge Nanocrystals: Kinetic Measurements byBerkeley, CA, 94720 ABSTRACT Ge nanocrystals are formed inthe Raman spectra of the Ge nanocrystals in-situ. The

  17. Ferromagnetism in Mn-Implanted Epitaxially Grown Ge on Si(100)

    E-Print Network [OSTI]

    Guchhait, S.

    2011-01-01T23:59:59.000Z

    segregation in Mn-doped Ge”, Journal of Applied Physics 101,Room-temperature ferromagnetism in Ge 1-x Mn x nanowires”,BC high-?/metal gate Ge/C alloy pMOSFETs fabricated directly

  18. Clues to the nature of SN 2009ip from photometric and spectroscopic evolution to late times

    SciTech Connect (OSTI)

    Graham, M. L. [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Sand, D. J. [Physics Department, Texas Tech University, Lubbock, TX 79409 (United States); Valenti, S.; Howell, D. A.; Parrent, J. [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Halford, M.; Zaritsky, D. [Astronomy Department, University of Arizona, Tucson, AZ 85721 (United States); Bianco, F. [Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Rest, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Dilday, B., E-mail: melissagraham@berkeley.edu [North Idaho College, 1000 W. Garden Avenue, Coeur d'Alene, ID 83814 (United States)

    2014-06-01T23:59:59.000Z

    We present time series photometric and spectroscopic data for the transient SN 2009ip from the start of its outburst in 2012 September until 2013 November. These data were collected primarily with the new robotic capabilities of the Las Cumbres Observatory Global Telescope Network, a specialized facility for time domain astrophysics, and includes supporting high-resolution spectroscopy from the Southern Astrophysical Research Telescope, Kitt Peak National Observatory, and Gemini Observatory. Based on our nightly photometric monitoring, we interpret the strength and timing of fluctuations in the light curve as interactions between fast-moving ejecta and an inhomogeneous circumstellar material (CSM) produced by past eruptions of this massive luminous blue variable (LBV) star. Our time series of spectroscopy in 2012 reveals that, as the continuum and narrow H? flux from CSM interactions declines, the broad component of H? persists with supernova (SN)-like velocities that are not typically seen in LBVs or SN impostor events. At late times, we find that SN 2009ip continues to decline slowly, at ? 0.01 mag day{sup –1}, with small fluctuations in slope similar to Type IIn supernovae (SNe IIn) or SN impostors but no further LBV-like activity. The late-time spectrum features broad calcium lines similar to both late-time SNe and SN impostors. In general, we find that the photometric and spectroscopic evolution of SN 2009ip is more similar to SNe IIn than either continued eruptions of an LBV star or SN impostors but we cannot rule out a nonterminal explosion. In this context, we discuss the implications for episodic mass loss during the late stages of massive star evolution.

  19. Origins of low resistivity and Ge donor level in Ge ion-implanted ZnO bulk single crystals

    SciTech Connect (OSTI)

    Kamioka, K.; Oga, T.; Izawa, Y.; Kuriyama, K. [College of Engineering and Research Center of Ion Beam Technology, Hosei University Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Departments of Arts and Sciences, Osaka Kyoiku University Kashiwara, Osaka 582-8582 (Japan)

    2013-12-04T23:59:59.000Z

    The energy level of Ge in Ge-ion implanted ZnO single crystals is studied by Hall-effect and photoluminescence (PL) methods. The variations in resistivity from ?10{sup 3} ?cm for un-implanted samples to ?10{sup ?2} ?cm for as-implanted ones are observed. The resistivity is further decreased to ?10{sup ?3} ?cm by annealing. The origins of the low resistivity are attributed to both the zinc interstitial (Zn{sub i}) related defects and the electrical activated Ge donor. An activation energy of Ge donors estimated from the temperature dependence of carrier concentration is 102 meV. In PL studies, the new peak at 372 nm (3.33 eV) related to the Ge donor is observed in 1000 °C annealed samples.

  20. GeO{sub 2}/Ge structure submitted to annealing in deuterium: Incorporation pathways and associated oxide modifications

    SciTech Connect (OSTI)

    Bom, N. M., E-mail: nicolau.bom@ufrgs.br [PGMICRO, UFRGS, 91509-900 Porto Alegre, Rio Grande do Sul (Brazil); Soares, G. V.; Hartmann, S.; Bordin, A. [Instituto de Física, UFRGS, 91509-900 Porto Alegre, Rio Grande do Sul (Brazil); Radtke, C. [Instituto de Química, UFRGS, 91509-900 Porto Alegre, Rio Grande do Sul (Brazil)

    2014-10-06T23:59:59.000Z

    Deuterium (D) incorporation in GeO{sub 2}/Ge structures following D{sub 2} annealing was investigated. Higher D concentrations were obtained for GeO{sub 2}/Ge samples in comparison to their SiO{sub 2}/Si counterparts annealed in the same conditions. Oxygen vacancies produced during the annealing step in D{sub 2} constitute defect sites for D incorporation, analogous to defects at the SiO{sub 2}/Si interfacial region. Besides D incorporation, volatilization of the oxide layer is also observed as a consequence of D{sub 2} annealing, especially in the high temperature regime of the present study (>450?°C). In parallel to this volatilization, the stoichiometry and chemical structure of remnant oxide are modified as well. These results evidence the broader impact of forming gas annealing in dielectric/Ge structures with respect to SiO{sub 2}/Si counterparts.

  1. Atomic geometry of mixed Ge-Si dimers in the initial-stage growth of Ge on Si,,001...2 1 X. Chen* and D. K. Saldin

    E-Print Network [OSTI]

    Saldin, Dilano

    Atomic geometry of mixed Ge-Si dimers in the initial-stage growth of Ge on Si,,001...2 1 X. Chen quantitatively the geometry of mixed Ge-Si dimers on a single domain Si 001 2 1 surface by azimuthal scanning core-level photoelectron diffraction. By analyzing Ge 3d diffraction patterns from Ge/Si 001 at 0.1 ML

  2. The electrochemical reactions of SnO2 with Li and Na: a study using thin films and mesoporous carbons

    SciTech Connect (OSTI)

    Gorka, Joanna [ORNL; Baggetto, Loic [ORNL; Keum, Jong Kahk [ORNL; Mahurin, Shannon Mark [ORNL; Mayes, Richard T [ORNL; Dai, Sheng [ORNL; Veith, Gabriel M [ORNL

    2015-01-01T23:59:59.000Z

    In this work we have determined the room temperature electrochemical reactivity of SnO2 thin films and mesoporous carbons filled with SnO2 anodes with Na, and compare the results with those obtained during the reaction with Li. We show that SnO2 can reversibly deliver up to 6.2 Li/SnO2 whereas the reaction with Na is significantly limited. The initial discharge capacity is equivalent to less than 4 Na/SnO2, which is expected to correspond to the formation of 2 Na2O and Sn. This limited discharge capacity suggests the negative role of the formed Na2O matrix upon the reversible reaction of Sn clusters. Moreover, the reversible cycling of less than 1 Na/SnO2, despite the utilization of 6-7 nm SnO2 particles, is indicative of sluggish reaction kinetics. The origin of this significant capacity reduction is likely due to the formation of a diffusion limiting interface. Furthermore, there is a larger apparent hysteresis compared to Li. These results point to the need to design composite structures of SnO2 nanoparticles with suitable morphological and conductivity components.

  3. Preparation and photocatalytic properties of AgI–SnO{sub 2} nano-composites

    SciTech Connect (OSTI)

    Wen, Biao; Wang, Xiao-Hui; Lu, Juan; Cao, Jia-Lei [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215021 (China); Wang, Zuo-Shan, E-mail: zuoshanwang@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215021 (China); State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2013-05-15T23:59:59.000Z

    Highlights: ? AgI–SnO{sub 2} nano-composites have been successfully synthesized. ? As-prepared AgI–SnO{sub 2} nano-composites own the excellent visible light photocatalytic activity. ? As-prepared AgI–SnO{sub 2} nano-composites own the excellent stability. - Abstract: AgI doped SnO{sub 2} nano-composites were prepared by the chemical coprecipitation method and were characterized by the X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Results showed that main of the I{sup ?} ions remained in the AgI lattice which is highly dispersed in the system. The photo-catalytic experiments performed under visible light irradiation using methylene blue as the pollutant revealed that not only the photo-catalytic activity but also the stability of SnO{sub 2} based photocatalyst could be improved by introduction of an appropriate amount of AgI, and the result was further supported by the UV–Vis diffuse reflection spectra and the electron spin-resonance spectra. Among all of the samples, AgI–SnO{sub 2} nano-composite with 2At% AgI exhibited the best catalytic efficiency and stability.

  4. THE OLD ENVIRONMENT OF THE FAINT CALCIUM-RICH SUPERNOVA SN 2005cz

    SciTech Connect (OSTI)

    Perets, Hagai B. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02338 (United States); Gal-yam, Avishay [Weizmann Institute of Science, POB 26, Rehovot (Israel); Crockett, R. Mark; Sullivan, Mark [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Anderson, Joseph P. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); James, Phil A. [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD (United Kingdom); Neill, James D. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Leonard, Douglas C. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States)

    2011-02-20T23:59:59.000Z

    The supernova SN 2005cz has recently attracted some attention due to the fact that it was spectroscopically similar to type Ib supernovae (SNe Ib), a class that is presumed to result from the core collapse of massive stars, yet it occurred in an elliptical galaxy, where one expects very few massive stars to exist. Two explanations for this remarkable event were put forward. Perets et al. associate SN 2005cz with the class of Ca-rich, faint SNe Ib, which likely result from old double-white-dwarf systems with an He-rich secondary. On the other hand, Kawabata et al. suggest that SN 2005cz is indeed a core-collapse event (in a binary system), albeit of a star at the lower end of the mass range, 10-12 M{sub sun}. The existence of this star in its elliptical host is explained as resulting from low-level star formation (SF) activity in that galaxy. Here we present extensive observations of the location of SN 2005cz, sensitive to a variety of SF tracers, including optical spectroscopy, H{alpha} emission, UV emission, and Hubble Space Telescope photometry. We show that NGC 4589, the host galaxy of SN 2005cz, does not show any signatures of a young stellar population or recent SF activity either close to or far from the location of SN 2005cz.

  5. Shock Breakout Emission from a Type Ib/c Supernova: XRT 080109/SN 2008D

    E-Print Network [OSTI]

    Roger A. Chevalier; Claes Fransson

    2010-01-29T23:59:59.000Z

    The X-ray flash 080109, associated with SN 2008D, can be attributed to the shock breakout emission from a normal Type Ib/c supernova. If the observed emission is interpreted as blackbody emission, the temperature and radiated energy are close to expectations, considering that scattering dominates absorption processes so that spectrum formation occurs deep within the photosphere. The X-ray emission observed at ~10 days is attributed to inverse Compton scattering of photospheric photons with relativistic electrons produced in the interaction of the supernova with the progenitor wind. A simple model for the optical/ultraviolet emission from shock breakout is developed and applied to SN 1987A, SN 1999ex, SN 2008D, and SN 2006aj, all of which have optical emission observed at t~1 day. The emission from the first three can plausibly be attributed to shock breakout emission. The photospheric temperature is most sensitive to the radius of the progenitor star core and the radii in these cases are in line with expectations from stellar evolution. The early optical/ultraviolet observations of SN 2006aj cannot be accommodated by a shock breakout model in a straightforward way.

  6. SN 2009ib: A Type II-P Supernova with an Unusually Long Plateau

    E-Print Network [OSTI]

    Takats, K; Pumo, M L; Paillas, E; Zampieri, L; Elias-Rosa, N; Benetti, S; Bufano, F; Cappellaro, E; Ergon, M; Fraser, M; Hamuy, M; Inserra, C; Kankare, E; Smartt, S J; Stritzinger, M D; Van Dyk, S D; Haislip, J B; LaCluyze, A P; Moore, J P; Reichart, D

    2015-01-01T23:59:59.000Z

    We present optical and near-infrared photometry and spectroscopy of SN 2009ib, a Type II-P supernova in NGC 1559. This object has moderate brightness, similar to those of the intermediate-luminosity SNe 2008in and 2009N. Its plateau phase is unusually long, lasting for about 130 days after explosion. The spectra are similar to those of the subluminous SN 2002gd, with moderate expansion velocities. We estimate the $^{56}$Ni mass produced as $0.046 \\pm 0.015\\,{\\rm M}_{\\sun}$. We determine the distance to SN 2009ib using both the expanding photosphere method (EPM) and the standard candle method. We also apply EPM to SN 1986L, a type II-P SN that exploded in the same galaxy. Combining the results of different methods, we conclude the distance to NGC 1559 as $D=19.8 \\pm 2.8$ Mpc. We examine archival, pre-explosion images of the field taken with the Hubble Space Telescope, and find a faint source at the position of the SN, which has a yellow colour ($(V-I)_0 = 0.85$ mag). Assuming it is a single star, we estimate i...

  7. Origin of the pearl necklace of SN1987A

    E-Print Network [OSTI]

    Jacques Moret-Bailly

    2006-07-12T23:59:59.000Z

    The bright circles observed around stars are usually considered as produced by shock waves; but this interpretation does not explain easily the bright spots of the "pearl necklace" of NS 1987A supernova. Assuming that the central object of SN 1987A is a neutron star heated by the accretion of a low density cloud, non-linear optics, in particular superradiance and impulsive stimulated Raman scattering (ISRS), is needed to take into account the high intensity of the radiated light. Where the temperature of the surrounding gas decreases enough to allow a combination of protons and electrons into atomic hydrogen in despite of the low density, a spherical shell absorbs in particular the Lyman alpha line, but does not populate much the 2P state because a tangential superradiance appears until the exciting line is almost absorbed; the increase of the 2P population resulting from the disappearance of the superradiance produces a redshift, so that almost all energy of a wide band is transferred to tangential modes making an UV pearl necklace in a given direction of observation. In a column of UV light making a pearl, atomic lines are excited enough to produce new, co-linear superradiances, in particular visible.

  8. Stable retrograde orbits around the triple system 2001 SN263

    E-Print Network [OSTI]

    Araujo, R A N; Prado, A F B A

    2015-01-01T23:59:59.000Z

    The NEA 2001 SN263 is the target of the ASTER MISSION - First Brazilian Deep Space Mission. Araujo et al. (2012), characterized the stable regions around the components of the triple system for the planar and prograde cases. Knowing that the retrograde orbits are expected to be more stable, here we present a complementary study. We now considered particles orbiting the components of the system, in the internal and external regions, with relative inclinations between $90^{\\circ}< I \\leqslant180^{\\circ}$, i.e., particles with retrograde orbits. Our goal is to characterize the stable regions of the system for retrograde orbits, and then detach a preferred region to place the space probe. For a space mission, the most interesting regions would be those that are unstable for the prograde cases, but stable for the retrograde cases. Such configuration provide a stable region to place the mission probe with a relative retrograde orbit, and, at the same time, guarantees a region free of debris since they are expect...

  9. Episodic Mass Loss and Pre-SN Circumstellar Envelopes

    E-Print Network [OSTI]

    Nathan Smith

    2008-02-13T23:59:59.000Z

    I discuss observational clues concerning episodic mass-loss properties of massive stars in the time before the final supernova explosion. In particular, I will focus on the mounting evidence that LBVs and related stars are candidates for supernova progenitors, even though current paradigms place them at the end of core-H burning. Namely, conditions in the immediate circumstellar environment within a few 10$^2$ AU of Type IIn supernovae require very high progenitor mass-loss rates. Those rates are so high that the only known stars that come close are LBVs during rare giant eruptions. I will highlight evidence from observations of some recent extraordinary supernovae suggesting that explosive or episodic mass loss (a.k.a. LBV eruptions like the 19th century eruption of Eta Car) occur in the 5-10 years immediately preceding the SN. Finally, I will discuss some implications for stellar evolution from these SNe, the most important of which is the observational fact that the most massive stars can indeed make it to the ends of their lives with substantial H envelopes intact, even at Solar metallicity.

  10. Extended and Revised Analysis of Singly Ionized Tin: Sn II

    E-Print Network [OSTI]

    Haris, K; Tauheed, A

    2013-01-01T23:59:59.000Z

    The electronic structure of singly ionized tin (SnII) is partly a one-electron and partly a three-electron system with ground configuration 5s25p. The excited configurations are of the type 5s2nl in the one-electron part, and 5s5p2, 5p3 and 5s5pnl (nl = 6s, 5d) in the three-electron system with quartet and doublet levels. The spectrum analyzed in this work was recorded on a 3 m normal incidence vacuum spectrograph of the Antigonish laboratory (Canada) in the wavelength region 300 - 2080 {\\AA} using a triggered spark source. The existing interpretation of the one-electron level system was confirmed in this paper, while the 2S1/2 level of the 5s5p2 configuration has been revised. The analysis has been extended to include new configurations 5p3, 5s5p5d and 5s5p6s with the aid of superposition-of-configurations Hartree-Fock calculations with relativistic corrections. The ionization potential obtained from the ng series was found to be 118023.7(5) 1/cm (14.63307(6) eV). We give a complete set of critically evaluat...

  11. THE PROGENITOR OF SN 2011ja: CLUES FROM CIRCUMSTELLAR INTERACTION

    SciTech Connect (OSTI)

    Chakraborti, Sayan [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ray, Alak; Yadav, Naveen [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Colaba, Mumbai 400 005 (India); Smith, Randall [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ryder, Stuart [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia); Sutaria, Firoza [Indian Institute of Astrophysics, Koramangala, Bangalore (India); Dwarkadas, Vikram V. [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Chandra, Poonam [Department of Physics, Royal Military College of Canada, Kingston, ON K7K 7B4 (Canada); Pooley, David [Department of Physics, Sam Houston State University, Huntsville, TX (United States); Roy, Rupak, E-mail: schakraborti@fas.harvard.edu [Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital (India)

    2013-09-01T23:59:59.000Z

    Massive stars, possibly red supergiants, which retain extended hydrogen envelopes until core collapse, produce Type II plateau (IIP) supernovae. The ejecta from these explosions shocks the circumstellar matter originating from the mass loss of the progenitor during the final phases of its life. This interaction accelerates particles to relativistic energies which then lose energy via synchrotron radiation in the shock-amplified magnetic fields and inverse Compton scattering against optical photons from the supernova. These processes produce different signatures in the radio and X-ray parts of the electromagnetic spectrum. Observed together, they allow us to break the degeneracy between shock acceleration and magnetic field amplification. In this work, we use X-rays observations from the Chandra and radio observations from the Australia Telescope Compact Array to study the relative importance of processes which accelerate particles and those which amplify magnetic fields in producing the non-thermal radiation from SN 2011ja. We use radio observations to constrain the explosion date. Multiple Chandra observations allow us to probe the history of variable mass loss from the progenitor. The ejecta expands into a low-density bubble followed by interaction with a higher density wind from a red supergiant consistent with M{sub ZAMS} {approx}> 12 M{sub Sun }. Our results suggest that a fraction of Type IIP supernovae may interact with circumstellar media set up by non-steady winds.

  12. GeV Emission from Collisional Magnetized Gamma Ray Bursts

    E-Print Network [OSTI]

    P. Mészáros; M. J. Rees

    2011-04-26T23:59:59.000Z

    Magnetic fields may play a dominant role in gamma-ray bursts, and recent observations by the Fermi satellite indicate that GeV radiation, when detected, arrives delayed by seconds from the onset of the MeV component. Motivated by this, we discuss a magnetically dominated jet model where both magnetic dissipation and nuclear collisions are important. We show that, for parameters typical of the observed bursts, such a model involving a realistic jet structure can reproduce the general features of the MeV and a separate GeV radiation component, including the time delay between the two. The model also predicts a multi-GeV neutrino component.

  13. Efficient tunable luminescence of SiGe alloy sheet polymers

    SciTech Connect (OSTI)

    Vogg, G.; Meyer, A. J.-P.; Miesner, C.; Brandt, M. S.; Stutzmann, M.

    2001-06-18T23:59:59.000Z

    Crystalline SiGe alloy sheet polymers were topotactically prepared from epitaxially grown calcium germanosilicide Ca(Si{sub 1{minus}x}Ge{sub x}){sub 2} precursor films in the whole composition range. These polygermanosilynes are found to be a well-defined mixture of the known siloxene and polygermyne sheet polymers with the OH groups exclusively bonded to silicon. The optical properties determined by photoluminescence and optical reflection measurements identify the mixed SiGe sheet polymers as direct semiconductors with efficient luminescence tunable in the energy range between 2.4 and 1.3 eV. {copyright} 2001 American Institute of Physics.

  14. Spin-polarized photoemission from SiGe heterostructures

    SciTech Connect (OSTI)

    Ferrari, A.; Bottegoni, F.; Isella, G.; Cecchi, S.; Chrastina, D.; Finazzi, M.; Ciccacci, F. [LNESS-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2013-12-04T23:59:59.000Z

    We apply the principles of Optical Orientation to measure by Mott polarimetry the spin polarization of electrons photoemitted from different group-IV heterostructures. The maximum measured spin polarization, obtained from a Ge/Si{sub 0.31}Ge{sub 0.69} strained film, undoubtedly exceeds the maximum value of 50% attainable in bulk structures. The explanation we give for this result lies in the enhanced band orbital mixing between light hole and split-off valence bands as a consequence of the compressive strain experienced by the thin Ge layer.

  15. Measurement of the in-medium K0 inclusive cross section in pi- -induced reactions at 1.15 GeV/c

    E-Print Network [OSTI]

    M. L. Benabderrahmane; N. Herrmann; K. Wisniewski; J. Kecskemeti; A. Andronic; V. Barret; Z. Basrak; N. Bastid; P. Buehler; M. Cargnelli; R. Caplar; E. Cordier; I. Deppner; P. Crochet; P. Dupieux; M. Dzelalija; L. Fabbietti; Z. Fodor; P. Gasik; I. Gasparic; Y. Grishkin; O. N. Hartmann; K. D. Hildenbrand; B. Hong; T. I. Kang; P. Kienle; M. Kirejczyk; Y. J. Kim; M. Kis; P. Koczon; M. Korolija; R. Kotte; A. Lebedev; Y. Leifels; X. Lopez; V. Manko; J. Marton; A. Mangiarotti; M. Merschmeyer; T. Matulewicz; M. Petrovici; K. Piasecki; F. Rami; A. Reischl; W. Reisdorf; M. S. Ryu; P. Schmidt; A. Schuttauf; Z. Seres; B. Sikora; K. S. Sim; V. Simion; K. Siwek-Wilczynska; V. Smolyankin; K. Suzuki; Z. Tyminski; E. Widmann; Z. G. Xiao; T. Yamazaki; I. Yushmanov; X. Y. Zhang; A. Zhilin; J. Zmeskal; E. Bratkovskaya; W. Cassing

    2009-03-20T23:59:59.000Z

    The K0 meson production by pi- mesons of 1.15 GeV/c momentum on C, Al, Cu, Sn and Pb nuclear targets was measured with the FOPI spectrometer at the SIS accelerator of GSI. Inclusive production cross-sections and the momentum distributions of K0 mesons are compared to scaled elementary production cross-sections and to predictions of theoretical models describing the in-medium production of kaons. The data represent a new reference for those models, which are widely used for interpretation of the strangeness-production in heavy-ion collisions. The presented results demonstrate the sensitivity of the kaon production to the reaction amplitudes inside nuclei and point to the existence of a repulsive KN-potential of 20+-5 MeV at normal nuclear matter density.

  16. Optical absorption in highly-strained Ge/SiGe quantum wells: the role of ?-to-? scattering

    E-Print Network [OSTI]

    L. Lever; Z. Ikoni?; A. Valavanis; R. W. Kelsall; M. Myronov; D. R. Leadley; Y. Hu; N. Owens; F. Y. Gardes; G. T. Reed

    2013-02-28T23:59:59.000Z

    We report the observation of the quantum-confined Stark effect in Ge/SiGe multiple quantum well heterostructures grown on Si(0.22)Ge(0.78) virtual substrates. The large compressive strain in the Ge quantum well layers caused by the lattice mismatch with the virtual substrate results in a blue shift of the direct absorption edge, as well as a reduction in the \\Gamma-valley scattering lifetime because of strain-induced splittings of the conduction band valleys. We investigate theoretically the \\Gamma-valley carrier lifetimes by evaluating the \\Gamma-to-L and \\Gamma-to-\\Delta{} scattering rates in strained Ge/SiGe semiconductor heterostructures. These scattering rates are used to determine the lifetime broadening of excitonic peaks and the indirect absorption in simulated absorption spectra, which are compared with measured absorption spectra for quantum well structures with systematically-varied dimensions. We find that \\Gamma-to-\\Delta{} scattering is significant in compressively strained Ge quantum wells and that the \\Gamma-valley electron lifetime is less than 50 fs in the highly-strained structures reported here, where \\Gamma-to-\\Delta{} scattering accounted for approximately half of the total scattering rate.

  17. Effect of annealing atmosphere on the structure and luminescence of Sn-implanted SiO{sub 2} layers

    SciTech Connect (OSTI)

    Lopes, J.M.J.; Zawislak, F.C.; Fichtner, P.F.P.; Lovey, F.C.; Condo, A.M. [Instituto de Fisica - UFRGS, Cx. Postal 15051, 91501-970 Porto Alegre (Brazil); Departamento de Metalurgia, Escola de Engenharia - UFRGS, Porto Alegre (Brazil); Centro Atomico Bariloche, 8400 S.C. Bariloche (Argentina)

    2005-01-10T23:59:59.000Z

    Sn nanoclusters are synthesized in 180 nm SiO{sub 2} layers after ion implantation and heat treatment. Annealings in N{sub 2} ambient at high temperatures (T{>=}700 deg. C) lead to the formation of Sn nanoclusters of different sizes in metallic and in oxidized phases. High-resolution transmission electron microscopy (TEM) analyses revealed that the formed larger nanoparticles are composed by a Sn metallic core and a SnO{sub x} shell. The corresponding blue-violet photoluminescence (PL) presents low intensity. However, for heat treatments in vacuum, the PL intensity is increased by a factor of 5 and the TEM data show a homogeneous size distribution of Sn nanoclusters. The low intensity of PL for the N{sub 2} annealed samples is associated with Sn oxidation.

  18. Growth of an {alpha}-Sn film on an InSb(111) A-(2x2) surface

    SciTech Connect (OSTI)

    Kondo, Daiyu; Sakamoto, Kazuyuki; Shima, Masahide; Takeyama, Wakaba [Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Nakamura, Kenya; Ono, Kanta; Oshima, Masaharu [Department of Applied Chemistry, Graduate School of Engineering, University of Tokyo, Tokyo 113-0033 (Japan); Kasukabe, Yoshitaka [Department of Electronic Engineering/International Student Center, Tohoku University, Sendai 980-8578 (Japan)

    2004-12-15T23:59:59.000Z

    We have investigated the initial growth process of {alpha}-Sn films on the In-terminated InSb(111)A-(2x2) surface using low-energy electron diffraction (LEED) and high-resolution core-level photoelectron spectroscopy. Taking the LEED observation and the Sn coverage-dependent integrated intensities of the In 4d, Sb 4d, and Sn 4d core-level spectra into account, we conclude that the {alpha}-Sn film grows epitaxially by a bilayer mode and that there is no interdiffusion of the substrate atoms as suggested in the literature. Furthermore, the coverage-dependent In 4d and Sn 4d core levels indicate that the In vacancy site of InSb(111)A-(2x2) surface is not the preferable Sn absorption site.

  19. GE Store for Technology is Open for Business | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) Environmental AssessmentsGeoffrey Campbell isOklahoma City, USAGE BBQ Center isThe GE

  20. Greatly improved interfacial passivation of in-situ high ? dielectric deposition on freshly grown molecule beam epitaxy Ge epitaxial layer on Ge(100)

    SciTech Connect (OSTI)

    Chu, R. L. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Liu, Y. C.; Lee, W. C.; Huang, M. L.; Kwo, J., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lin, T. D.; Hong, M., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Pi, T. W. [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)

    2014-05-19T23:59:59.000Z

    A high-quality high-?/Ge interface has been achieved by combining molecule beam epitaxy grown Ge epitaxial layer and in-situ deposited high ? dielectric. The employment of Ge epitaxial layer has sucessfully buried and/or removed the residue of unfavorable carbon and native oxides on the chemically cleaned and ultra-high vacuum annealed Ge(100) wafer surface, as studied using angle-resolved x-ray photoelectron spectroscopy. Moreover, the scanning tunneling microscopy analyses showed the significant improvements in Ge surface roughness from 3.5?Å to 1?Å with the epi-layer growth. Thus, chemically cleaner, atomically more ordered, and morphologically smoother Ge surfaces were obtained for the subsquent deposition of high ? dielectrics, comparing with those substrates without Ge epi-layer. The capacitance-voltage (C-V) characteristics and low extracted interfacial trap density (D{sub it}) reveal the improved high-?/Ge interface using the Ge epi-layer approach.

  1. Atomic layer-by-layer oxidation of Ge (100) and (111) surfaces by plasma post oxidation of Al{sub 2}O{sub 3}/Ge structures

    SciTech Connect (OSTI)

    Zhang, Rui [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan) [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); School of Electronic Science and Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Huang, Po-Chin; Lin, Ju-Chin; Takenaka, Mitsuru; Takagi, Shinichi [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)] [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2013-02-25T23:59:59.000Z

    The ultrathin GeO{sub x}/Ge interfaces formed on Ge (100) and (111) surfaces by applying plasma post oxidation to thin Al{sub 2}O{sub 3}/Ge structures are characterized in detail using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy. It is found that the XPS signals assigned to Ge 1+ and the 2+ states in the GeO{sub x} layers by post plasma oxidation have oscillating behaviors on Ge (100) surfaces in a period of {approx}0.3 nm with an increase in the GeO{sub x} thickness. Additionally, the oscillations of the signals assigned to Ge 1+ and 2+ states show opposite phase to each other. The similar oscillation behaviors are also confirmed on Ge (111) surfaces for Ge 1+ and 3+ states in a period of {approx}0.5 nm. These phenomena can be strongly regarded as an evidence of the atomic layer-by-layer oxidation of GeO{sub x}/Ge interfaces on Ge (100) and (111) surfaces.

  2. Development and test of Nb3sn cos-theta coils made of high-jc rrp strands

    SciTech Connect (OSTI)

    Bossert, R.; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Feher, S.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Novitski, I.; Pischalnikov, Yu.; Sylvester, C.; Tartaglia, M.; Turrioni, D.; Yamada, R.; Zlobin, A.V.; /Fermilab

    2005-10-01T23:59:59.000Z

    A series of 1-m long Nb3Sn dipole magnets have been built at Fermilab in an attempt to refine the wind-and-react technology for Nb{sub 3}Sn conductor. Models have been made with MJR and PIT strand with varying degrees of success. Subsequently two new dipole ''mirror'' magnets based on RRP Nb{sub 3}Sn coils were constructed and tested. This paper describes the design, fabrication and test results of those magnets.

  3. Investigations of segregation phenomena in highly strained Mn-doped Ge wetting layers and Ge quantum dots embedded in silicon

    SciTech Connect (OSTI)

    Prestat, E., E-mail: eric.prestat@gmail.com; Porret, C.; Favre-Nicolin, V.; Tainoff, D.; Boukhari, M.; Bayle-Guillemaud, P.; Jamet, M.; Barski, A., E-mail: andre.barski@cea.com [INAC, SP2M, CEA and Université Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble (France)

    2014-03-10T23:59:59.000Z

    In this Letter, we investigate manganese diffusion and the formation of Mn precipitates in highly strained, few monolayer thick, Mn-doped Ge wetting layers and nanometric size Ge quantum dot heterostructures embedded in silicon. We show that in this Ge(Mn)/Si system manganese always precipitates and that the size and the position of Mn clusters (precipitates) depend on the growth temperature. At high growth temperature, manganese strongly diffuses from germanium to silicon, whereas decreasing the growth temperature reduces the manganese diffusion. In the germanium quantum dots layers, Mn precipitates are detected, not only in partially relaxed quantum dots but also in fully strained germanium wetting layers between the dots.

  4. Axial SiGe Heteronanowire Tunneling Field-Effect Transistors...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    tunneling field-effect transistors (TFETs), where on-state tunneling occurs in the Ge drain section, while off-state leakage is dominated by the Si junction in the source. Our...

  5. Technology makes reds "pop" in LED displays | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Reveal and Energy Smart consumer brands, and Evolve(tm), GTx(tm), Immersion(tm), Infusion(tm), Lumination(tm), Albeo(tm) and Tetra commercial brands, all trademarks of GE....

  6. Taking on the World's Toughest Problems | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    direct write2square The GE Store for Technology is Open for Business 2-4-13-v-3d-printing-medical-devices Invention Factory: How Will The World Get Smaller? ...

  7. Carrier Density Modulation in Ge Heterostructure by Ferroelectric Switching

    SciTech Connect (OSTI)

    Ponath, Patrick [University of Texas at Austin; Fredrickson, Kurt [University of Texas at Austin; Posadas, Agham B. [University of Texas at Austin; Ren, Yuan [University of Texas at Austin; Vasudevan, Rama K [ORNL; Okatan, Mahmut Baris [ORNL; Jesse, Stephen [ORNL; Aoki, Toshihiro [Arizona State University; McCartney, Martha [Arizona State University; Smith, David J [Arizona State University; Kalinin, Sergei V [ORNL; Lai, Keji [University of Texas at Austin; Demkov, Alexander A. [University of Texas at Austin

    2015-01-01T23:59:59.000Z

    The development of nonvolatile logic through direct coupling of spontaneous ferroelectric polarization with semiconductor charge carriers is nontrivial, with many issues, including epitaxial ferroelectric growth, demonstration of ferroelectric switching, and measurable semiconductor modulation. Here we report a true ferroelectric field effect carrier density modulation in an underlying Ge(001) substrate by switching of the ferroelectric polarization in the epitaxial c-axis-oriented BaTiO3 (BTO) grown by molecular beam epitaxy (MBE) on Ge. Using density functional theory, we demonstrate that switching of BTO polarization results in a large electric potential change in Ge. Aberration-corrected electron microscopy confirms the interface sharpness, and BTO tetragonality. Electron-energy-loss spectroscopy (EELS) indicates the absence of any low permittivity interlayer at the interface with Ge. Using piezoelectric force microscopy (PFM), we confirm the presence of fully switchable, stable ferroelectric polarization in BTO that appears to be single domain. Using microwave impedance microscopy (MIM), we clearly demonstrate a ferroelectric field effect.

  8. Direct band gap narrowing in highly doped Ge

    E-Print Network [OSTI]

    Han, Zhaohong

    Direct band gap narrowing in highly doped n-type Ge is observed through photoluminescence measurements by determining the spectrum peak shift. A linear relationship between the direct band gap emission and carrier concentration ...

  9. Growth strategies to control tapering in Ge nanowires

    SciTech Connect (OSTI)

    Periwal, P.; Baron, T., E-mail: thierry.baron@cea.fr; Salem, B.; Bassani, F. [Laboratoire des Technologies de la Microelectronique (LTM), UMR 5129 CNRS-UJF, CEA Grenoble, 17 Rue des Martyrs, 38054 Grenoble (France); Gentile, P. [SiNaPs Laboratory SP2M, UMR-E, CEA/UJF-Grenoble 1, INAC, 38054 Grenoble (France)

    2014-04-01T23:59:59.000Z

    We report the effect of PH{sub 3} on the morphology of Au catalyzed Ge nanowires (NWs). Ge NWs were grown on Si (111) substrate at 400?°C in the presence of PH{sub 3}, using vapor-liquid-solid method by chemical vapor deposition. We show that high PH{sub 3}/GeH{sub 4} ratio causes passivation at NW surface. At high PH{sub 3} concentration phosphorous atoms attach itself on NW surface and form a self-protection coating that prevents conformal growth and leads to taper free nanostructures. However, in case of low PH{sub 3} flux the combination of axial and radial growth mechanism occurs resulting in conical structure. We have also investigated axial PH{sub 3}-intrinsic junctions in Ge NWs. The unusual NW shape is attributed to a combination of catalyzed, uncatalyzed and diffusion induced growth.

  10. Nanocrystalline Ge Flash Memories: Electrical Characterization and Trap Engineering

    E-Print Network [OSTI]

    Kan, Eric Win Hong

    Conventional floating gate non-volatile memories (NVMs) present critical issues for device scalability beyond the sub-90 nm node, such as gate length and tunnel oxide thickness reduction. Nanocrystalline germanium (nc-Ge) ...

  11. Discovery of Isotopes of Elements with Z $\\ge$ 100

    E-Print Network [OSTI]

    M. Thoennessen

    2012-03-09T23:59:59.000Z

    Currently, 163 isotopes of elements with Z $\\ge$ 100 have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  12. Ge-on-Si laser operating at room temperature

    E-Print Network [OSTI]

    Liu, Jifeng

    Monolithic lasers on Si are ideal for high-volume and large-scale electronic–photonic integration. Ge is an interesting candidate owing to its pseudodirect gap properties and compatibility with Si complementary metal oxide ...

  13. High-Speed Network Enables Industrial Internet | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) GE Unveils High-Speed Network Infrastructure to Connect Machines, Data and People at Light...

  14. GE Software Expert Julian Keith Loren Discusses Innovation and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GE Software Expert Julian Keith Loren Discusses Innovation and the Industrial Internet Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window)...

  15. Technology "Relay Race" Against Cancer | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GE Scientists in Technology "Relay Race" Against Cancer Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new...

  16. An Update on the Brazil Tech Center | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    desde meu ultimo update a voces sobre o Centro de Pesquisas da GE no Rio de Janeiro, Brasil e tambm minha terra natal 2011 foi um timo ano para mim. Depois de viver na...

  17. Construction progresses at GE's Oil & Gas Technology Center ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    progressing at GE's newest research center, the Oil & Gas Technology Center in Oklahoma City Click to email this to a friend (Opens in new window) Share on Facebook (Opens...

  18. ECS Transactions 3, (7), 1211-1222 (2006) Characterization of Strained Si/SiGe with Raman, Pulsed MOS Capacitor

    E-Print Network [OSTI]

    Schroder, Dieter K.

    2006-01-01T23:59:59.000Z

    ECS Transactions 3, (7), 1211-1222 (2006) 1211 Characterization of Strained Si/SiGe with Raman silicon/relaxed SiGe/graded SiGe/Si samples. The effective generation lifetime depends on the defect defective SiGe. GOI statistical analysis shows worsening oxide breakdown as the Ge concentration in the SiGe

  19. A new class of materials with promising thermoelectric properties: MNiSn (M=Ti, Zr, Hf)

    SciTech Connect (OSTI)

    Hohl, H.; Ramirez, A.P.; Kaefer, W.; Fess, K.; Thurner, Ch.; Kloc, Ch.; Bucher, E.

    1997-07-01T23:59:59.000Z

    TiNiSn, ZrNiSn and HfNiSn are members of a large group of intermetallic compounds which crystallize in the cubic MgAgAs-type structure. Polycrystalline samples of these compounds have been prepared and investigated for their thermoelectric properties. With thermopowers of about {minus}200 {micro}V/K and resistivities of a few m{Omega}cm, power factors S{sup 2}/{rho} as high as 38 {micro}W/K{sup 2}cm were obtained at 700 K. These remarkably high power factors are, however, accompanied by a thermal conductivity, solid solutions Zr{sub 1{minus}x}Hf{sub x}NiSn, Zr{sub 1{minus}x}Ti{sub x}NiSn, and Hf{prime}{sub 1{minus}x}Ti{sub x}NiSn were formed. The figure of merit of Zr{sub 0.5}Hf{sub 0.5}NiSn at 700 K (ZT = 0.41) exceeds the end members ZrNiSn (ZT = 0.26) and HfNiSn (ZT = 0.22).

  20. Nearby Supernova Factory Observations of SN 2006D: On Sporadic Carbon Signatures in Early Type Ia Supernova Spectra

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    with low volume-?lling factor. Subject headings: supernovae:general — supernovae: individual (SN 2006D)Introduction Type Ia supernovae (SNe Ia) make valuable

  1. The Jefferson Lab 12 GeV Upgrade

    E-Print Network [OSTI]

    McKeown, R D

    2010-01-01T23:59:59.000Z

    Construction of the 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility is presently underway. This upgrade includes doubling the energy of the electron beam to 12 GeV, the addition of a new fourth experimental hall, and the construction of upgraded detector hardware. An overview of this upgrade project is presented, along with highlights of the anticipated experimental program.

  2. The Jefferson Lab 12 GeV Upgrade

    E-Print Network [OSTI]

    R. D. McKeown

    2010-09-22T23:59:59.000Z

    Construction of the 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility is presently underway. This upgrade includes doubling the energy of the electron beam to 12 GeV, the addition of a new fourth experimental hall, and the construction of upgraded detector hardware. An overview of this upgrade project is presented, along with highlights of the anticipated experimental program.

  3. AC transport in p-Ge/GeSi quantum well in high magnetic fields

    SciTech Connect (OSTI)

    Drichko, I. L.; Malysh, V. A.; Smirnov, I. Yu.; Golub, L. E.; Tarasenko, S. A. [A.F. Ioffe Physical Technical Institute of Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation); Suslov, A. V. [National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Mironov, O. A. [Warwick SEMINANO R and D Center, University of Warwick Science Park, Coventry CV4 7EZ (United Kingdom); Kummer, M.; Känel, H. von [Laboratorium für Festkörperphysik ETH Zürich, CH-8093 Zürich (Switzerland)

    2014-08-20T23:59:59.000Z

    The contactless surface acoustic wave technique is implemented to probe the high-frequency conductivity of a high-mobility p-Ge/GeSi quantum well structure in the regime of integer quantum Hall effect (IQHE) at temperatures 0.3–5.8 K and magnetic fields up to 18 T. It is shown that, in the IQHE regime at the minima of conductivity, holes are localized and ac conductivity is of hopping nature and can be described within the “two-site” model. The analysis of the temperature and magnetic-field-orientation dependence of the ac conductivity at odd filing factors enables us to determine the effective hole g-factor, |g{sub zz}|?4.5. It is shown that the in-plane component of the magnetic field leads to a decrease in the g-factor as well as increase in the cyclotron mass, which is explained by orbital effects in the complex valence band of germanium.

  4. Members of a workshop at the tenth IAYC Conference, July 7, 2006 1. ge -hak -te le -ber, ge -fil -te -fish: sha-bes iz a far -ge -ni -gn

    E-Print Network [OSTI]

    Finkel, Raphael

    A SUDE Members of a workshop at the tenth IAYC Conference, July 7, 2006 = 90 4 4 1. ge - hak - te le - ber, ge - fil - te - fish: sha- bes iz a far - ge - ni - gn 2. kha - le gri - vn, ku - gl yoykh: ku - men on di ma - khe - to - nem. 3. shtru - dl, tsi - mes, zi - se kalte: a su - de vos men vet ge

  5. Co silicide formation on SiGeC/Si and SiGe/Si layers R. A. Donatona)

    E-Print Network [OSTI]

    on the total strain energy in the layer and restricts the applications where high Ge concentrations are needed spectrometry, secondary ion mass spectroscopy SIMS , and four point probe for sheet resistance measure- ments

  6. Trap and recombination centers study in sprayed Cu?ZnSnS? thin films

    SciTech Connect (OSTI)

    Courel, Maykel, E-mail: maykelcourel@gmail.com; Vigil-Galán, O.; Jiménez-Olarte, D. [Escuela Superior de Física y Matemáticas-Instituto Politécnico Nacional (IPN), C.P. 07738, México DF (Mexico); Espíndola-Rodríguez, M. [Escuela Superior de Física y Matemáticas-Instituto Politécnico Nacional (IPN), C.P. 07738, México DF (Mexico); Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adrià de Besòs, Barcelona (Spain); Saucedo, E. [Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adrià de Besòs, Barcelona (Spain)

    2014-10-07T23:59:59.000Z

    In this work, a study of trap and recombination center properties in polycrystalline Cu?ZnSnS? thin films is carried out in order to understand the poor performance in Cu?ZnSnS? thin film solar cells. Thermally stimulated current has been studied in Cu?ZnSnS? deposited by pneumatic spray pyrolysis method using various heating rates, in order to gain information about trap centers and/or deep levels present within the band-gap of this material. A set of temperature-dependent current curves revealed three levels with activation energy of 126±10, 476±25, and 1100±100 meV. The possible nature of the three levels found is presented, in which the first one is likely to be related to Cu{sub Zn} antisites, while second and third to Sn vacancies and Sn{sub Cu} antisites, respectively. The values of frequency factor, capture cross section, and trap concentration have been determined for each center.

  7. SnTe field effect transistors and the anomalous electrical response of structural phase transition

    SciTech Connect (OSTI)

    Li, Haitao, E-mail: haitao.li@nist.gov; Zhu, Hao; Yuan, Hui; Li, Qiliang, E-mail: qli6@gmu.edu [Department of Electrical and Computer Engineering, George Mason University, Fairfax, Virginia 22030 (United States); Semiconductor and Dimensional Metrology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); You, Lin; Kopanski, Joseph J. [Department of Electrical and Computer Engineering, George Mason University, Fairfax, Virginia 22030 (United States); Richter, Curt A. [Semiconductor and Dimensional Metrology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Zhao, Erhai [School of Physics, Astronomy, and Computational Sciences, George Mason University, Fairfax, Virginia 22030 (United States)

    2014-07-07T23:59:59.000Z

    SnTe is a conventional thermoelectric material and has been newly found to be a topological crystalline insulator. In this work, back-gate SnTe field-effect transistors have been fabricated and fully characterized. The devices exhibit n-type transistor behaviors with excellent current-voltage characteristics and large on/off ratio (>10{sup 6}). The device threshold voltage, conductance, mobility, and subthreshold swing have been studied and compared at different temperatures. It is found that the subthreshold swings as a function of temperature have an apparent response to the SnTe phase transition between cubic and rhombohedral structures at 110?K. The abnormal and rapid increase in subthreshold swing around the phase transition temperature may be due to the soft phonon/structure change which causes the large increase in SnTe dielectric constant. Such an interesting and remarkable electrical response to phase transition at different temperatures makes the small SnTe transistor attractive for various electronic devices.

  8. Spectroscopic Observations and Analysis of the Unusual Type Ia SN1999ac

    SciTech Connect (OSTI)

    Garavini, G.; Aldering, G.; Amadon, A.; Amanullah, R.; Astier,P.; Balland, C.; Blanc, G.; Conley, A.; Dahlen, T.; Deustua, S.E.; Ellis,R.; Fabbro, S.; Fadeyev, V.; Fan, X.; Folatelli, G.; Frye, B.; Gates,E.L.; Gibbons, R.; Goldhaber, G.; Goldman, B.; Goobar, A.; Groom, D.E.; Haissinski, J.; Hardin, D.; Hook, I.; Howell, D.A.; Kent, S.; Kim, A.G.; Knop, R.A.; Kowalski, M.; Kuznetsova, N.; Lee, B.C.; Lidman, C.; Mendez,J.; Miller, G.J.; Moniez, M.; Mouchet, M.; Mourao, A.; Newberg, H.; Nobili, S.; Nugent, P.E.; Pain, R.; Perdereau, O.; Perlmutter, S.; Quimby, R.; Regnault, N.; Rich, J.; Richards, G.T.; Ruiz-Lapuente, P.; Schaefer, B.E.; Schahmaneche, K.; Smith, E.; Spadafora, A.L.; Stanishev,V.; Thomas, R.C.; Walton, N.A.; Wang, L.; Wood-Vasey, W.M.

    2005-07-12T23:59:59.000Z

    The authors present optical spectra of the peculiar Type Ia supernova (SN Ia) 1999ac. The data extend from -15 to +42 days with respect to B-band maximum and reveal an event that is unusual in several respects. prior to B-band maximum, the spectra resemble those of SN 1999aa, a slowly declining event, but possess stronger Si II and Ca II signatures (more characteristic of a spectroscopically normal SN). Spectra after B-band maximum appear more normal. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from Si II are among the slowest ever observed, though SN 1999ac is not particularly dim. The analysis of the parameters v{sub 10}(Si II), R(Si II), v, and {Delta}m{sub 15} further underlines the unique characteristics of SN 1999ac. They find convincing evidence of C II {lambda}6580 in the day -15 spectrum with ejection velocity v > 16,000 km s{sup -1}, but this signature disappears by day -9. This rapid evolution at early times highlights the importance of extremely early-time spectroscopy.

  9. TYCHO SN 1572: A NAKED Ia SUPERNOVA REMNANT WITHOUT AN ASSOCIATED AMBIENT MOLECULAR CLOUD

    SciTech Connect (OSTI)

    Tian, W. W. [National Astronomical Observatories, CAS, Beijing 100012 (China); Leahy, D. A., E-mail: tww@bao.ac.cn [Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)

    2011-03-10T23:59:59.000Z

    The historical supernova remnant (SNR) Tycho SN 1572 originates from the explosion of a normal Type Ia supernova that is believed to have originated from a carbon-oxygen white dwarf in a binary system. We analyze the 21 cm continuum, H I, and {sup 12}CO-line data from the Canadian Galactic Plane Survey in the direction of SN 1572 and the surrounding region. We construct H I absorption spectra to SN 1572 and three nearby compact sources. We conclude that SN 1572 has no molecular cloud interaction, which argues against previous claims that a molecular cloud is interacting with the SNR. This new result does not support a recent claim that dust, newly detected by AKARI, originates from such an SNR-cloud interaction. We suggest that the SNR has a kinematic distance of 2.5-3.0 kpc based on a nonlinear rotational curve model. Very high energy {gamma}-ray emission from the remnant has been detected by the VERITAS telescope, so our result shows that its origin should not be an SNR-cloud interaction. Both radio and X-ray observations support that SN 1572 is an isolated Type Ia SNR.

  10. Shock Breakout Emission from a Type Ib/c Supernova: XRF 080109/SN 2008D

    E-Print Network [OSTI]

    Chevalier, Roger A

    2008-01-01T23:59:59.000Z

    The X-ray flash 080109, associated with SN 2008D, can be attributed to the shock breakout emission from a normal Type Ib/c supernova. If the observed emission is interpreted as blackbody emission, the temperature and radiated energy are close to expectations, considering that scattering dominates absorption processes so that spectrum formation occurs deep within the photosphere. The X-ray emission observed at ~10 days is attributed to inverse Compton scattering of photospheric photons with relativistic electrons produced in the interaction of the supernova with the progenitor wind. A simple model for the optical/ultraviolet emission from shock breakout is developed and applied to SN 1987A, SN 1999ex, SN 2008D, and SN 2006aj, all of which have optical emission observed at t~1 day. The emission from the first three can plausibly be attributed to shock breakout emission. The photospheric temperature is most sensitive to the radius of the progenitor star core and the radii in these cases are in line with expectat...

  11. Anisotropic flow in Cu plus Au collisions at root s(N N)=200GeV RID A-2398-2009 

    E-Print Network [OSTI]

    Chen, LW; Ko, Che Ming.

    2006-01-01T23:59:59.000Z

    compressedmatter formed in noncentral heavy-ion collisions [2,3] and is sensitive to the properties of producedmatter in these collisions. For heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC), it has been shown that this sensitivity exists...AGeV at RHIC. Use is made of both the default version and the version with string melting, that is, a version allowing hadrons that are expected to be formed from initial strings to convert to their valence quarks and antiquarks [10...

  12. Anisotropic flow in Cu plus Au collisions at root s(N N)=200GeV RID A-2398-2009

    E-Print Network [OSTI]

    Chen, LW; Ko, Che Ming.

    2006-01-01T23:59:59.000Z

    in these collisions are appreciable and show an asymmetry in forward and backward rapidities. DOI: 10.1103/PhysRevC.73.014906 PACS number(s): 25.75.Ld, 24.10.Lx I. INTRODUCTION There have been extensive studies on the azimuthal anisotropy of hadronmomentum..., 663 (1997). [2] J. Barrette et al. (E877 Collaboration), Phys. Rev. Lett. 73, 2532 (1994). [3] H. Appelshauser et al. (NA49 Collaboration), Phys. Rev. Lett. 80, 4136 (1998). [4] J. Y. Ollitrault, Phys. Rev. D 46, 229 (1992). [5] H. Sorge, Phys...

  13. GE & AE Extension Request Form, Version 7, Feb 2013, JC Program Change

    E-Print Network [OSTI]

    Escher, Christine

    GE & AE Extension Request Form, Version 7, Feb 2013, JC Program Change Pathway Today's Date to General English. How many sessions of GE do you wish to request? 1 2 3 4 (GE sessions are 5 weeks) How many GE hours do you wish to take? 21 hours 27 hours OR ____ I am a Pathway student, and I would like

  14. CTu2J.1.pdf CLEO Technical Digest OSA 2012 Light Emission in Ge Quantum Wells

    E-Print Network [OSTI]

    Miller, David A. B.

    CTu2J.1.pdf CLEO Technical Digest © OSA 2012 Light Emission in Ge Quantum Wells Edward T. Fei1 Engineering, Stanford University, Stanford, CA 94305, USA edfei@stanford.edu Abstract: We present the Ge/SiGe and electroluminescence show enhanced optical properties over bulk Ge. Further optical enhancement is observed in disk

  15. College of Engineering Partner Schools Australia Melbourne University, Melbourne GE3*

    E-Print Network [OSTI]

    Lee, Tonghun

    College of Engineering Partner Schools Australia Melbourne University, Melbourne ­ GE3* University of New South Wales, New South Wales ­ GE3* Austria Technical University of Vienna, Vienna - GE3* Chile Universidad del Bio Bio, Concepcion China Xiamen University, Xiamen ­ GE3* Denmark Aalborg University, Aalborg

  16. On the Comparison of Fisher Information of the Weibull and GE Distributions

    E-Print Network [OSTI]

    Kundu, Debasis

    On the Comparison of Fisher Information of the Weibull and GE Distributions Rameshwar D. Gupta exponen- tial (GE) and Weibull distributions for complete and Type-I censored observations. Fisher is much more than the GE distribution. We compute the total information of the Weibull and GE

  17. C-band side-entry Ge quantum-well electroabsorption modulator on SOI

    E-Print Network [OSTI]

    Miller, David A. B.

    C-band side-entry Ge quantum-well electroabsorption modulator on SOI operating at 1 V swing J. Modulation was due to the quantum-confined Stark effect from ten Ge/SiGe quantum wells epitaxially grown the totally internally reflecting air-SiGe interface and a frustrated total internal reflection from

  18. University of California and HRL Laboratories, LLC. All rights reserved. SiGe/Si SUPERLATTICE COOLERS

    E-Print Network [OSTI]

    © University of California and HRL Laboratories, LLC. All rights reserved. SiGe/Si SUPERLATTICE and characterization of SiGe/Si superlattice coolers are described. Superlattice structures were used to enhance for SiGe/Si superlattice coolers. SiGe is a good thermoelectric material for high temperature

  19. Strain Relaxation of SiGe on Compliant BPSG and Its Applications

    E-Print Network [OSTI]

    Strain Relaxation of SiGe on Compliant BPSG and Its Applications Haizhou Yin A DISSERTATION of SiGe on compliant borophosphosilicate glass (BPSG). Through modeling and experiments it has been shown that strain relaxation in the SiGe film can be induced by lateral expansion and buckling of the SiGe

  20. OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR Xunming Deng

    E-Print Network [OSTI]

    Deng, Xunming

    OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR CELLS Xunming Deng Department cells, all employing high- quality a-SiGe cells, are reviewed in this paper. Incorporating various improvements in device fabrication, the UT group fabricated 1) triple-junction a-Si/a-SiGe/a- SiGe solar cells

  1. SiGe virtual substrate HMOS transistor for analogue applications K. Michelakisa,*

    E-Print Network [OSTI]

    Papavassiliou, Christos

    SiGe virtual substrate HMOS transistor for analogue applications K. Michelakisa,* , S Abstract Silicon­germanium (SiGe) heterojunction metal-oxide-semiconductor field-effect transistors (SiGe design. The results suggest that the realisation of buried-channel SiGe n-HMOSFETs is feasible in MOS

  2. SiGe-On-Insulator (SGOI): Two Structures for CMOS Application

    E-Print Network [OSTI]

    SiGe-On-Insulator (SGOI): Two Structures for CMOS Application Zhiyuan Cheng,a) Jongwan Jung, b Massachusetts Avenue, Cambridge, MA 02141 a) E-mail: cheng@alum.MIT.EDU Abstract ­ Two SiGe-on-insulator (SGOI enhancement on both electron and hole mobilities. Keywords ­ strained-Si, SiGe, SiGe-on-Insulator, SGOI

  3. Strain-induced self-assembly of Ge nanodashes, nanodumbbells, and dot chains on Si(001)

    SciTech Connect (OSTI)

    Zhang, J. J. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany) [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany); Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Schmidt, O. G. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany) [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany); Center for Advancing Electronics Dresden, TU Dresden (Germany)

    2013-09-30T23:59:59.000Z

    We investigate the growth of self-assembled Ge nanostructures on top of embedded Ge nanowires on Si(001) substrates. Ge nanostructures, such as nanodashes, nanodumbbells, and dot chains are observed simply by tuning the growth temperature and thickness of the Si spacer between the Ge layers. The self-assembly process is governed by the surface strain fields generated by the embedded Ge nanowires and is well-described by our theoretical calculations. The catalyst-free and horizontal growth of such Ge nanostructures directly on Si(001) is attractive for investigating exotic transport properties through Si/Ge-based quantum devices.

  4. Background p(450 GeV/c)-p,d (NA51)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    #12;#12;Background ' Open charm J / Drell-Yan #12;* p(450 GeV/c)-p,d (NA51) 208 16 p(200 Ge) 32 p(450 GeV/c)-A (A=C,Al,Cu,W) (NA38) 10101 10101010 652 3 4 B targetprojectile B(J/)/(AB)(nb) 5 4 3 Pb(208x158 GeV/c)-Pb (NA50) S(32x200 GeV/c)-U (NA38) p(200 GeV/c)-W (NA38) p(450 GeV/c)-A (A=p,d) (NA

  5. Photoluminescence and positron annihilation spectroscopy investigation of (Ge, Er) codoped Si oxides deposited by magnetron sputtering

    SciTech Connect (OSTI)

    Heng, C. L.; Chelomentsev, E.; Peng, Z. L.; Mascher, P. [Department of Engineering Physics and Centre for Emerging Device Technologies, McMaster University, Hamilton, Ontario L8S 4K1 (Canada); Simpson, P. J. [Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)

    2009-01-01T23:59:59.000Z

    We have investigated the nature of violet-blue emission from (Ge, Er) codoped Si oxides (Ge+Er+SiO{sub 2}) using photoluminescence (PL) and positron annihilation spectroscopy (PAS) measurements. The PL spectra and PAS analysis for a control Ge-doped SiO{sub 2} (Ge+SiO{sub 2}) indicate that Ge-associated neutral oxygen vacancies (Ge-NOV) are likely responsible for the major emission in the violet-blue band. For Ge+Er+SiO{sub 2}, both Ge-NOV and GeO color centers are believed to be responsible for the emission band. The addition of Er has a significant influence on the emission, which is discussed in terms of Er-concentration-related structural change in the Ge+Er+SiO{sub 2}.

  6. Cu2ZnSnS x O4 x and Cu2ZnSnS x Se4 x : First principles simulations of optimal alloy configurations and their energies

    E-Print Network [OSTI]

    Holzwarth, Natalie

    .1063/1.4819206 The role of secondary phase precipitation on grain boundary electrical activity in Cu2ZnSnS4 (CZTS in thin film solar cells, multicomponent copper chalcogenide based com- pounds, namely, Cu2ZnSnS4(CZTS sulphide CZTS device has reported an efficiency of 8.4%,5 whereas the best pure selenide CZTSe device has

  7. Construction and Test of 3.6 m Nb3Sn Racetrack Coils for LARP

    SciTech Connect (OSTI)

    Wanderer, P.; Ambrosio, G.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Cheng, D. W.; Cozzolino, J.; Dietderich, D.R.; Escallier, J.; Feher, S.; Ferracin, P.; Ganetis, G.; Ghosh, A. K.; Gupta, R. C.; Hafalia,, A. R.; Hannaford, C. R.; Joshi, P.; Kovach, P.; Lietzke, A. F.; Lizarazo, J.; Louie, W.; Marone, A.; McInturff, A.D.; Muratore, J.; Nobrega, F.; Sabbi, G.; Schmalzle, J.; Thomas, R.; Turrioni, D.

    2008-06-01T23:59:59.000Z

    Development of high-performance Nb{sub 3}Sn quadrupoles is one of the major goals of the LHC Accelerator Research Program (LARP). As part of this program, long racetrack magnets were made in order to check the fabrication steps for long Nb{sub 3}Sn coils, that the changes in coil length that take place during reaction and cooldown are correctly accounted for in the quadrupole design, and the use of a long aluminum shell for the support structure. This paper reports the construction of the first long Nb{sub 3}Sn magnet with racetrack coils 3.6 m long. The magnet reached a nominal 'plateau' at 9596 A after five quenches. This is about 90% of the estimated conductor limit. The peak field in the coils at this current was 11 T.

  8. Effect of Axial Loading on Quench Performance in Nb3Sn Magnets

    SciTech Connect (OSTI)

    Ambrosio, G.; Bordini, B.; Caspi, S.; Dietderich, D.R.; Felice, H.; Hafalia, A.R.; Hannaford, C.R.; Lizarazo, J.; Lietzke, A.F.; McInturff, A.D.; Sabbi, G.L.; DiMarco, J.D.; Tartaglia, M.; Vedrice, P.; Ferracin, P.

    2008-06-01T23:59:59.000Z

    A series of tests has been performed at Lawrence Berkeley National Laboratory (LBNL) and Fermi National Accelerator Laboratory (FNAL) with the goal of assessing the influence of coil axial pre-load on Nb{sub 3}Sn magnet training. The tests involved two subscale Nb{sub 3}Sn magnets: SQ02, a quadrupole magnet fabricated as part of the US LHC Accelerator Research Program (LARP), and SD01, a dipole magnet developed in collaboration between CEA/Saclay and LBNL. Both magnets used similar Nb{sub 3}Sn flat racetrack coils from LBNL Subscale Magnet Program, and implemented an axial support system composed of stainless steel end-plates and aluminum rods. The system was designed to withstand full longitudinal electro-magnetic forces and provide controllable preloads. Quench performances, training, and quench locations have been recorded in various axial loading conditions. Test results are reported.

  9. Construction and Test of 3.5 m Nb3Sn Racetrack Coils for LARP.

    SciTech Connect (OSTI)

    Wanderer,P.; Ambrosio, G.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Cheng, D.W.; Cozzolino, J.; Dietderich, D.R.; Escallier, J.; Feher, S.; Ferracin, P.; Ganetis, G.; Ghosh, A.K.; Gupta, R.C.; Hafalia, A.R.; Hannaford, C.R.; Joshi, P.; Kovach, P.; Lietzke, A.F.; Lizarazo, J.; Louie, W.; Marone, A.; McInturff, A.D.; Muratore, J.; Nobrega, R.; Sabbi, G.; Schmalzle, J.; Thomas, R.; Turrioni, D.

    2007-08-27T23:59:59.000Z

    Development of high-performance Nb{sub 3}Sn quadrupoles is one of the major goals of the LHC Accelerator Research Program (LARP). As part of this program, long racetrack magnets were made in order to check the fabrication steps for long Nb{sub 3}Sn coils, that the changes in coil length that take place during reaction and cooldown are correctly accounted for in the quadrupole design, and the use of a long aluminum shell for the support structure. This paper reports the construction of the first long Nb{sub 3}Sn magnet with racetrack coils 3.6 m long. The magnet reached a nominal 'plateau' at 9596 A after five quenches. This is about 90% of the estimated conductor limit. The peak field in the coils at this current was 11 T.

  10. Isomeric states close to doubly magic $^{132}$Sn studied with JYFLTRAP

    E-Print Network [OSTI]

    A. Kankainen; J. Hakala; T. Eronen; D. Gorelov; A. Jokinen; V. S. Kolhinen; I. D. Moore; H. Penttilä; S. Rinta-Antila; J. Rissanen; A. Saastamoinen; V. Sonnenschein; J. Äystö

    2012-06-27T23:59:59.000Z

    The double Penning trap mass spectrometer JYFLTRAP has been employed to measure masses and excitation energies for $11/2^-$ isomers in $^{121}$Cd, $^{123}$Cd, $^{125}$Cd and $^{133}$Te, for $1/2^-$ isomers in $^{129}$In and $^{131}$In, and for $7^-$ isomers in $^{130}$Sn and $^{134}$Sb. These first direct mass measurements of the Cd and In isomers reveal deviations to the excitation energies based on results from beta-decay experiments and yield new information on neutron- and proton-hole states close to $^{132}$Sn. A new excitation energy of 144(4) keV has been determined for $^{123}$Cd$^m$. A good agreement with the precisely known excitation energies of $^{121}$Cd$^m$, $^{130}$Sn$^m$, and $^{134}$Sb$^m$ has been found.

  11. Hubble Space Telescope WFPC2 Imaging of SN 1979C and Its Environment

    E-Print Network [OSTI]

    Schuyler D. Van Dyk; Chien Y. Peng; Aaron J. Barth; Alexei V. Filippenko; Roger A. Chevalier; Robert A. Fesen; Claes Fransson; Robert P. Kirshner; Bruno Leibundgut

    1998-10-22T23:59:59.000Z

    The locations of supernovae in the local stellar and gaseous environment in galaxies contain important clues to their progenitor stars. As part of a program to study the environments of supernovae using Hubble Space Telescope (HST) imaging data, we have examined the environment of the Type II-L SN 1979C in NGC 4321 (M100). We place more rigorous constraints on the mass of the SN progenitor, which may have had a mass M \\approx 17--18 M_sun. Moreover, we have recovered and measured the brightness of SN 1979C, m=23.37 in F439W (~B; m_B(max) = 11.6), 17 years after explosion. .

  12. Nanoscale structural heterogeneity in Ni-rich half-Heusler TiNiSn

    SciTech Connect (OSTI)

    Douglas, Jason E., E-mail: jedouglas@mrl.ucsb.edu; Pollock, Tresa M. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Materials Research Laboratory, University of California, Santa Barbara, California 93106 (United States); Chater, Philip A. [Diamond Light Source, Chilton, Oxfordshire OX11 0DE (United Kingdom); Brown, Craig M. [Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716 (United States); Seshadri, Ram [Materials Department, University of California, Santa Barbara, California 93106 (United States); Materials Research Laboratory, University of California, Santa Barbara, California 93106 (United States); Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106 (United States)

    2014-10-28T23:59:59.000Z

    The structural implications of excess Ni in the TiNiSn half-Heusler compound are examined through a combination of synchrotron x-ray and neutron scattering studies, in conjunction with first principles density functional theory calculations on supercells. Despite the phase diagram suggesting that TiNiSn is a line compound with no solid solution, for small x in TiNi{sub 1+x}Sn there is indeed an appearance—from careful analysis of the scattering—of some solubility, with the excess Ni occupying the interstitial tetrahedral site in the half-Heusler structure. The analysis performed here would point to the excess Ni not being statistically distributed, but rather occurring as coherent nanoclusters. First principles calculations of energetics, carried out using supercells, support a scenario of Ni interstitials clustering, rather than a statistical distribution.

  13. Valley splitting in Si quantum dots embedded in SiGe S. Srinivasan,1,2

    E-Print Network [OSTI]

    Rokhinson, Leonid

    Valley splitting in Si quantum dots embedded in SiGe S. Srinivasan,1,2 G. Klimeck,1,2 and L. P subband.4 Recently, calculations predicted that valley splitting in nar- row few nanometers SiGe/Si/SiGe that prediction, which has been explained12 by the disorders of the Si/SiGe interface and in the SiGe buffer

  14. Comparison of luminescent efficiency of InGaAs quantum well structures grown on Si, GaAs, Ge, and SiGe virtual substrate

    E-Print Network [OSTI]

    , and SiGe virtual substrate V. K. Yang, S. M. Ting, M. E. Groenert, M. T. Bulsara, M. T. Currie, C. W efficiency of InGaAs quantum wells on Si via SiGe interlayers, identical In0.2Ga0.8As quantum well structures metalorganic vapor deposition system. The substrates used include GaAs, Si, Ge, and SiGe virtual substrates

  15. Thickness dependent exchange bias in martensitic epitaxial Ni-Mn-Sn thin films

    SciTech Connect (OSTI)

    Behler, Anna [IFW Dresden, Institute for Complex Materials, P.O. Box 27 01 16, 01171 Dresden (Germany) [IFW Dresden, Institute for Complex Materials, P.O. Box 27 01 16, 01171 Dresden (Germany); Department of Physics, Institute for Solid State Physics, Dresden University of Technology, 01062 Dresden (Germany); Teichert, Niclas; Auge, Alexander; Hütten, Andreas [Department of Physics, Thin Films and Physics of Nanostructures, Bielefeld University, 33501 Bielefeld (Germany)] [Department of Physics, Thin Films and Physics of Nanostructures, Bielefeld University, 33501 Bielefeld (Germany); Dutta, Biswanath; Hickel, Tilmann [Max-Planck Institut für Eisenforschung, 40237 Düsseldorf (Germany)] [Max-Planck Institut für Eisenforschung, 40237 Düsseldorf (Germany); Waske, Anja [IFW Dresden, Institute for Complex Materials, P.O. Box 27 01 16, 01171 Dresden (Germany)] [IFW Dresden, Institute for Complex Materials, P.O. Box 27 01 16, 01171 Dresden (Germany); Eckert, Jürgen [IFW Dresden, Institute for Complex Materials, P.O. Box 27 01 16, 01171 Dresden (Germany) [IFW Dresden, Institute for Complex Materials, P.O. Box 27 01 16, 01171 Dresden (Germany); Institute of Materials Science, Dresden University of Technology, 01062 Dresden (Germany)

    2013-12-15T23:59:59.000Z

    A thickness dependent exchange bias in the low temperature martensitic state of epitaxial Ni-Mn-Sn thin films is found. The effect can be retained down to very small thicknesses. For a Ni{sub 50}Mn{sub 32}Sn{sub 18} thin film, which does not undergo a martensitic transformation, no exchange bias is observed. Our results suggest that a significant interplay between ferromagnetic and antiferromagnetic regions, which is the origin for exchange bias, is only present in the martensite. The finding is supported by ab initio calculations showing that the antiferromagnetic order is stabilized in the phase.

  16. Fusion reactions in collisions induced by Li isotopes on Sn targets

    SciTech Connect (OSTI)

    Fisichella, M.; Shotter, A. C.; Di Pietro, A.; Figuera, P.; Lattuada, M.; Marchetta, C.; Musumarra, A.; Pellegriti, M. G.; Ruiz, C.; Scuderi, V.; Strano, E.; Torresi, D.; Zadro, M. [Dipartimento di Fisica, Universita di Messina, Messina (Italy) and INFN-Laboratori Nazionali del Sud and sezione di Catania, Catania (Italy); School of Physics and Astronomy, University of Edinburgh, Edinburgh (United Kingdom) and TRIUMF, Vancouver (Canada); INFN-Laboratori Nazionali del Sud and sezione di Catania, Catania (Italy); INFN-Laboratori Nazionali del Sud and sezione di Catania, Catania, Italy and Dipartimento di Fisica ed Astronomia, Universita di Catania, Catania (Italy); INFN-Laboratori Nazionali del Sud and sezione di Catania, Catania (Italy); INFN- Laboratori Nazionali del Sud and sezione di Catania, Catania (Italy) and Dipartimento di Fisica ed Astronomia, Universita di Catania, Catania (Italy); TRIUMF, Vancouver (Canada); INFN-Laboratori Nazionali del Sud and sezione di Catania, Catania (Italy) and Dipartimento di Fisica ed Astronomia, Universita di Catania, Catania (Italy); Ruder Boskovic Institute, Zagreb (Croatia)

    2012-10-20T23:59:59.000Z

    Fusion cross sections for the {sup 6}Li+{sup 120}Sn and {sup 7}Li+{sup 119}Sn systems have been measured. We aim to search for possible effects due to the different neutron transfer Q-values, by comparing the fusion cross sections for the two systems below the barrier. This experiment is the first step of a wider systematic aiming to study the above problems in collisions induced by stable and unstable Li isotopes on tin all forming the same compound nucleus.

  17. Relaxation of optically stimulated resistance of thin SnO{sub 2} films

    SciTech Connect (OSTI)

    Russkih, D. V., E-mail: russcience@mail.ru; Rembeza, S. I. [Voronezh State Technical University (Russian Federation)

    2009-06-15T23:59:59.000Z

    The results of investigation of the effect of irradiation with photons from an L5013VC violet light-emitting diode (LED) with the wavelength of 400 nm and power of 76 mW on the resistance of the sensitive layer of SnO{sub 2}-based test structures of gas sensors in air before and after the high-temperature stabilizing annealing are presented. The features in the variation of the SnO{sub 2}-layer resistance in time are established when the LED is switched on and off.

  18. Enhanced collectivity in neutron-deficient Sn isotopes in energy functional based collective Hamiltonian

    E-Print Network [OSTI]

    Z. P. Li; C. Y. Li; J. Xiang; J. M. Yao; J. Meng

    2012-09-26T23:59:59.000Z

    The low-lying collective states in Sn isotopes are studied by a five-dimensional collective Hamiltonian with parameters determined from the triaxial relativistic mean-field calculations using the PC-PK1 energy density functional. The systematics for both the excitation energies of $2^+_1$ states and $B(E2;0^+_1\\to 2^+_1)$ values are reproduced rather well, in particular, the enhanced E2 transitions in the neutron-deficient Sn isotopes with Ncollectivity in the isotopes around N=58.

  19. Design of HQ -- a High Field Large Bore Nb3Sn Quadrupole Magnet for LARP

    SciTech Connect (OSTI)

    Felice, H.; Ambrosio, G.; Anerella, M.; Bossert, R.; Caspi, S.; Cheng, D.; Dietderich, D.; Ferracin, P.; Ghosh, A. K.; Hafalia, R.; Hannaford, C. R.; Kashikhin, V.; Schmalze, J.; Prestemon, S.; Sabbi, G. L.; Wanderer, P.; Zlobin, A. V.

    2008-08-17T23:59:59.000Z

    In support of the Large Hadron Collider luminosity upgrade, a large bore (120 mm) Nb{sub 3}Sn quadrupole with 15 T peak coil field is being developed within the framework of the US LHC Accelerator Research Program (LARP). The 2-layer design with a 15 mm wide cable is aimed at pre-stress control, alignment and field quality while exploring the magnet performance limits in terms of gradient, forces and stresses. In addition, HQ will determine the magnetic, mechanical, and thermal margins of Nb{sub 3}Sn technology with respect to the requirements of the luminosity upgrade at the LHC.

  20. The Giant Monopole Resonance in the Sn Isotopes: Why is Tin so "Fluffy"?

    E-Print Network [OSTI]

    U. Garg

    2006-08-03T23:59:59.000Z

    The isoscalar giant monopole resonance (GMR) has been investigated in a series of Sn isotopes (A=112--124) using inelstic scattering of 400-MeV alpha particles at extremely forward angles (including 0deg). The primary aim of the investigation has been to explore the role of the "symmetry-energy" term in the expression for nuclear incompressibility. It is found that the energies of the GMR in the Sn isotopes are significantly lower than those expected from the nuclear incompressibility previously extracted from the available data on the compressional-mode giant resonances.

  1. TEM Study on the Evolution of Ge Nanocrystals in Si Oxide Matrix as a Function of Ge Concentration and the Si Reduction Process

    E-Print Network [OSTI]

    Chew, Han Guan

    Growth and evolution of germanium (Ge) nanocrystals embedded into a silicon oxide (SiO?) system have been studied based on the Ge content of co-sputtered Ge-SiO? films using transmission electron microscopy (TEM) and X-ray ...

  2. SN 2011A: an low-luminosity interacting transient, with a double plateau and strong sodium absorption

    E-Print Network [OSTI]

    de Jaeger, T; Pignata, G; Hamuy, M; Kankare, E; Stritzinger, M D; Benetti, S; Bufano, F; Elias-Rosa, N; Folatelli, G; Förster, F; González-Gaitán, S; Gutiérrez, C P; Inserra, C; Kotak, R; Lira, P; Morrell, N; Taddia, F; Tomasella, L

    2015-01-01T23:59:59.000Z

    We present optical photometry and spectroscopy of the optical transient SN 2011A. Our data spans 140 days after discovery including $BVRIu'g'r'i'z'$ photometry and 11 epochs of optical spectroscopy. Originally classified as a type IIn supernova (SN IIn) due to the presence of narrow H$\\alpha$ emission, this object shows exceptional characteristics. Firstly, the light curve shows a double plateau; a property only observed before in the impostor SN 1997bs. Secondly, SN 2011A has a very low luminosity ($M_{V}=-15.72$), placing it between normal luminous SNe IIn and SN impostors. Thirdly, SN 2011A shows low velocity and high equivalent width absorption close to the sodium doublet, which increases with time and is most likely of circumstellar origin. This evolution is also accompanied by a change of line profile; when the absorption becomes stronger, a P-Cygni profile appears. We discuss SN 2011A in the context of interacting SNe IIn and SN impostors, which appears to confirm the uniqueness of this transient. Whil...

  3. Laser wavelength effects on the charge state resolved ion energy distributions from laser-produced Sn plasma

    E-Print Network [OSTI]

    Najmabadi, Farrokh

    Laser wavelength effects on the charge state resolved ion energy distributions from laser of laser wavelength on the charge state resolved ion energy distributions from laser-produced Sn plasma freely expanding into vacuum are investigated. Planar Sn targets are irradiated at laser wavelengths

  4. Relations between Au / Sn-W mineralizations and late hercynian granite: Preliminary results from the Schistose Domain of Galicia-

    E-Print Network [OSTI]

    Boyer, Edmond

    Relations between Au / Sn-W mineralizations and late hercynian granite: Preliminary results from, mesothermal mineralization, late hercynian granites, hydrothermalism, Galicia, Spain ABSTRACT : Au and W-Sn mineralization of the Schistose Domain of Galicia-Trás-os-Montes are spatially related to late hercynian granites

  5. Flux penetration into superconducting Nb3Sn in oblique magnetic fields Diana G. Gheorghe, Mariela Menghini, and Rinke J. Wijngaarden

    E-Print Network [OSTI]

    Wijngaarden, Rinke J.

    Flux penetration into superconducting Nb3Sn in oblique magnetic fields Diana G. Gheorghe, Mariela; published 14 June 2006 Penetration of magnetic flux into a rectangular platelet of superconducting Nb3Sn-II superconductors. For such an analysis, often the simplest solutions of the critical state problem are used, which

  6. Microwave Plasma Chemical Vapor Deposition of Nano-Structured Sn/C Composite Thin-Film Anodes for Li-ion Batteries

    E-Print Network [OSTI]

    Marcinek, M.

    2008-01-01T23:59:59.000Z

    Meeting on Lithium Batteries, Biarritz, France, June 18–23,Sn/C anodes for lithium batteries. Thin layers of graphiticKeywords: Sn/C; Lithium Batteries; Anode; Plasma; Microwave

  7. The metamorphosis of Supernova SN2008D/XRF080109: a link between Supernovae and GRBs/Hypernovae

    E-Print Network [OSTI]

    Mazzali, Paolo A; Della Valle, Massimo; Chincarini, Guido; Sauer, Daniel N; Benetti, Stefano; Pian, Elena; Piran, Tsvi; D'Elia, Valerio; Elias-Rosa, Nancy; Margutti, Raffaella; Pasotti, Francesco; Antonelli, L Angelo; Bufano, Filomena; Campana, Sergio; Cappellaro, Enrico; Covino, Stefano; D'Avanzo, Paolo; Fiore, Fabrizio; Fugazza, Dino; Gilmozzi, Roberto; Hunter, Deborah; Maguire, Kate; Maiorano, Elisabetta; Marziani, Paola; Masetti, Nicola; Mirabel, Felix; Navasardyan, Hripsime; Nomoto, Ken'ichi; Palazzi, Eliana; Pastorello, Andrea; Panagia, Nino; Pellizza, Leonardo J; Sari, Re'em; Smartt, Stephen; Tagliaferri, Gianpiero; Tanaka, Masaomi; Taubenberger, Stefan; Tominaga, Nozomu; Trundle, Carrie; Turatto, Massimo

    2008-01-01T23:59:59.000Z

    The only supernovae (SNe) to have shown early gamma-ray or X-ray emission thus far are overenergetic, broad-lined Type Ic SNe (Hypernovae - HNe). Recently, SN 2008D shows several novel features: (i) weak XRF, (ii) an early, narrow optical peak, (iii) disappearance of the broad lines typical of SNIc HNe, (iv) development of He lines as in SNeIb. Detailed analysis shows that SN 2008D was not a normal SN: its explosion energy (KE ~ 6*10^{51} erg) and ejected mass (~7 Msun) are intermediate between normal SNeIbc and HNe. We derive that SN 2008D was originally a ~30Msun star. When it collapsed a black hole formed and a weak, mildly relativistic jet was produced, which caused the XRF. SN 2008D is probably among the weakest explosions that produce relativistic jets. Inner engine activity appears to be present whenever massive stars collapse to black holes.

  8. The metamorphosis of Supernova SN2008D/XRF080109: a link between Supernovae and GRBs/Hypernovae

    E-Print Network [OSTI]

    Paolo A. Mazzali; Stefano Valenti; Massimo Della Valle; Guido Chincarini; Daniel N. Sauer; Stefano Benetti; Elena Pian; Tsvi Piran; Valerio D'Elia; Nancy Elias-Rosa; Raffaella Margutti; Francesco Pasotti; L. Angelo Antonelli; Filomena Bufano; Sergio Campana; Enrico Cappellaro; Stefano Covino; Paolo D'Avanzo; Fabrizio Fiore; Dino Fugazza; Roberto Gilmozzi; Deborah Hunter; Kate Maguire; Elisabetta Maiorano; Paola Marziani; Nicola Masetti; Felix Mirabel; Hripsime Navasardyan; Ken'ichi Nomoto; Eliana Palazzi; Andrea Pastorello; Nino Panagia; Leonardo J. Pellizza; Re'em Sari; Stephen Smartt; Gianpiero Tagliaferri; Masaomi Tanaka; Stefan Taubenberger; Nozomu Tominaga; Carrie Trundle; Massimo Turatto

    2008-07-10T23:59:59.000Z

    The only supernovae (SNe) to have shown early gamma-ray or X-ray emission thus far are overenergetic, broad-lined Type Ic SNe (Hypernovae - HNe). Recently, SN 2008D shows several novel features: (i) weak XRF, (ii) an early, narrow optical peak, (iii) disappearance of the broad lines typical of SNIc HNe, (iv) development of He lines as in SNeIb. Detailed analysis shows that SN 2008D was not a normal SN: its explosion energy (KE ~ 6*10^{51} erg) and ejected mass (~7 Msun) are intermediate between normal SNeIbc and HNe. We derive that SN 2008D was originally a ~30Msun star. When it collapsed a black hole formed and a weak, mildly relativistic jet was produced, which caused the XRF. SN 2008D is probably among the weakest explosions that produce relativistic jets. Inner engine activity appears to be present whenever massive stars collapse to black holes.

  9. Jefferson Lab 12 GeV CEBAF Upgrade

    SciTech Connect (OSTI)

    Claus Rode

    2010-04-01T23:59:59.000Z

    The existing continuous electron beam accelerator facility (CEBAF) at Thomas Jefferson National Accelerator Facility (TJNAF) is a 5-pass, recirculating cw electron Linac operating at ~6 GeV and is devoted to basic research in nuclear physics. The 12 GeV CEBAF Upgrade is a $310 M project, sponsored by the Department of Energy (DOE) Office of Nuclear Physics, that will expand its research capabilities substantially by doubling the maximum energy and adding major new experimental apparatus. The project received construction approval in September 2008 and has started the major procurement process. The cryogenic aspects of the 12 GeV CEBAF Upgrade includes: doubling the accelerating voltages of the Linacs by adding ten new high-performance, superconducting radiofrequency (SRF) cryomodules (CMs) to the existing 42 1/4 cryomodules; doubling of the 2 K cryogenics plant; and the addition of eight superconducting magnets.

  10. S5 0716+714 : GeV variability study

    E-Print Network [OSTI]

    Rani, B; Lott, B; Fuhrmann, L; Zensus, J A

    2013-01-01T23:59:59.000Z

    The GeV observations by Fermi-LAT give us the opportunity to characterize the high-energy emission (100 MeV - 300 GeV) variability properties of the BL Lac object S5 0716+714. In this study, we performed flux and spectral analysis of more than 3 year long (August 2008 to April 2012) Fermi-LAT data of the source. During this period, the source exhibits two different modes of flux variability with characteristic timescales of ~75 and ~140 days, respectively. We also notice that the flux variations are characterized by a weak spectral hardening. The GeV spectrum of the source shows a clear deviation from a simple power law, and is better explained by a broken power law. Similar to other bright Fermi blazars, the break energy does not vary with the source flux during the different activity states. We discuss several possible scenarios to explain the observed spectral break.

  11. The 6 GeV TMD Program at Jefferson Lab

    SciTech Connect (OSTI)

    Puckett, Andrew J. [University of Connecticut, JLAB

    2015-01-01T23:59:59.000Z

    The study of the transverse momentum dependent parton distributions (TMDs) of the nucleon in semi-inclusive deep-inelastic scattering (SIDIS) has emerged as one of the major physics motivations driving the experimental program using the upgraded 11 GeV electron beam at Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF). The accelerator construction phase of the CEBAF upgrade is essentially complete and commissioning of the accelerator has begun as of April, 2014. As the new era of CEBAF operations begins, it is appropriate to review the body of published and forthcoming results on TMDs from the 6 GeV era of CEBAF operations, discuss what has been learned, and discuss the key challenges and opportunities for the 11 GeV SIDIS program of CEBAF.

  12. Spin Structure with JLab 6 and 12 GeV

    SciTech Connect (OSTI)

    Jian-Ping Chen

    2012-02-01T23:59:59.000Z

    Highlights of JLab 6 GeV results on spin structure study and plan for 12 GeV program. Spin structure study is full of surprises and puzzles. A decade of experiments from JLab yield these exciting results: (1) valence spin structure; (2) precision measurements of g{sub 2}/d{sub 2} - high-twist; (3) spin sum rules and polarizabilities; and (4) first neutron transversity. There is a bright future as the 12 GeV Upgrade will greatly enhance our capability: (1) Precision determination of the valence quark spin structure flavor separation; (2) Precision measurements of g{sub 2}/d{sub 2}; and (3) Precision extraction of transversity/tensor charge.

  13. Reducing 68Ge Background in Dark Matter Experiments

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Orrell, John L.

    2011-03-01T23:59:59.000Z

    Experimental searches for dark matter include experiments with sub-0.5 keV-energy threshold high purity germanium detectors. Experimental efforts, in partnership with the CoGeNT Collaboration operating at the Soudan Underground Laboratory, are focusing on energy threshold reduction via noise abatement, reduction of backgrounds from cosmic ray generated isotopes, and ubiquitous environmental radioactive sources. The most significant cosmic ray produced radionuclide is 68Ge. This paper evaluates reducing this background by freshly mining and processing germanium ore. The most probable outcome is a reduction of the background by a factor of two, and at most a factor of four. A very cost effective alternative is to obtain processed Ge as soon as possible and store it underground for 18 months.

  14. Reflection high-energy electron diffraction evaluation of thermal deoxidation of chemically cleaned Si, SiGe, and Ge layers for solid-source molecular beam epitaxy

    SciTech Connect (OSTI)

    Ali, Dyan; Richardson, Christopher J. K. [Laboratory for Physical Sciences, University of Maryland, College Park, Maryland 20740 (United States)

    2012-11-15T23:59:59.000Z

    The authors present a study on the thermal evolution of the reflection high-energy electron diffraction pattern of chemically cleaned (001)-oriented Si, Ge, and SiGe surfaces, associating observed changes in the reconstructions with the desorption of known residual contaminants for Si and Ge surfaces. The implications of residual oxides prior to epitaxy on stacking fault densities in the grown films are presented. Further evidence for the two-phase nature of oxides on SiGe surfaces is provided, demonstrating that it is necessary to heat a SiGe surface up to the thermal deoxidation temperature of a Si surface to obtain stacking fault-free growth.

  15. C incorporation in epitaxial Ge1yCy layers grown on Ge,,001...: An ab initio study D. Gall, J. D'Arcy-Gall, and J. E. Greene

    E-Print Network [OSTI]

    Gall, Daniel

    C incorporation in epitaxial Ge1ÀyCy layers grown on Ge,,001...: An ab initio study D. Gall, J. D lattice site configurations in fully coherent Ge1 yCy layers grown on Ge 001 . Calculations using strained configuration involving only one C atom per configura- tion. The bond-centered interstitial and the Ge-C split

  16. EBIC characterization of strained Si/SiGe heterostructures

    SciTech Connect (OSTI)

    Yakimov, E. B. [Russian Academy of Sciences, Institute of Microelectronics Technology and High-Purity Materials (Russian Federation)], E-mail: yakimov@ipmt-hpm.ac.ru; Zhang, R. H.; Rozgonyi, G. A. [North Carolina State University, Department of Materials Science and Engineering (United States); Seacrist, M. [MEMC Electronic Materials (United States)

    2007-04-15T23:59:59.000Z

    Strained-Si/SiGe heterostructure is studied by EBIC. The effect of annealing at 800 deg. C is investigated. The EBIC images obtained at different beam energies are analyzed. The analysis of images obtained shows that misfit dislocation bunches in the graded SiGe layer could not explain the cross-hatch contrast dependence on E{sub b}. Therefore, at least a part of this contrast should be associated with other defects located closer to the depletion region. It is assumed that dislocation trails could play the role of such defects.

  17. One dimensional Si/Sn -based nanowires and nanotubes for lithium-ion energy storage materials

    E-Print Network [OSTI]

    Cui, Yi

    One dimensional Si/Sn - based nanowires and nanotubes for lithium-ion energy storage materials Nam of advanced energy storage applications. In this feature article, we review recent progress on Si-based NWs to their uneven energy production. From this perspective, the interest in energy storage technology is on the rise

  18. Irradiation requirements of Nb3Sn based SC magnets electrical insulation

    E-Print Network [OSTI]

    McDonald, Kirk

    Irradiation requirements of Nb3Sn based SC magnets electrical insulation developed within the Eu electrical insulation candidates · EuCARD insulators certification conditions · Post irradiation tests and neutrino factories will be subjected to very high radiation doses. · The electrical insulation employed

  19. IS SN 0142-2499 MINISTRY OF AGRICULTURE FISHERIES AND FOOD

    E-Print Network [OSTI]

    IS SN 0142-2499 MINISTRY OF AGRICULTURE FISHERIES AND FOOD DIRECTORATE OF FISHERIES RESEARCH OF THE BRITISH ISLES, 1984 G..HUNT LOWESTOFT 1 9 8 5 #12;MINISTRY OF AGRICULTURE,FISHERIES AND FOOD DIRECTORATE 3.4 Methodsof interpretation 4. British Nuclear Fuels plc (BNFL) 4.1 Sellafield,Cumbria 4

  20. Cu2ZnSnS4 nanocrystals and graphene quantum dots for photovoltaics Xukai Xinab

    E-Print Network [OSTI]

    Lin, Zhiqun

    Cu2ZnSnS4 nanocrystals and graphene quantum dots for photovoltaics Jun Wang,a Xukai Xinab advances in the synthesis and utilization of CZTS nanocrystals and colloidal GQDs for photovoltaics emerged to achieve low cost, high perfor- mance photovoltaics, including organic solar cells,2­6 dye

  1. Microstructure and Interdiffusion of Template-Synthesized Au/Sn/Au

    E-Print Network [OSTI]

    and Sn in porous polycarbonate membranes were investigated by X-ray diffraction, HRTEM, STEM, EDS at low temperatures.12-14 Experimental studies have shown that patterned normal metal conducting leads) into commercially available polycarbonate membranes (Structure Probe Inc.). The quoted pore diameters and thickness

  2. Instrumentation for Measurement of Strain Dependence of Nb3Sn Conductors National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Instrumentation for Measurement of Strain Dependence of Nb3Sn Conductors National High Magnetic Field Laboratory Magnet Science and Technology, Florida State University An NHMFL User Collaboration Grants Program (UCGP) award is supporting students from the FAMU-FSU College of Engineering as part

  3. High thermoelectric performance by resonant dopant indium in nanostructured SnTe

    E-Print Network [OSTI]

    Liao, Bolin

    From an environmental perspective, lead-free SnTe would be preferable for solid-state waste heat recovery if its thermoelectric figure-of-merit could be brought close to that of the lead-containing chalcogenides. In this ...

  4. Supernova SN1987A Revisited as a Major Production Site for r-Process Elements

    E-Print Network [OSTI]

    Takuji Tsujimoto; Toshikazu Shigeyama

    2001-09-20T23:59:59.000Z

    The origin of nucleosynthesis products of rapid neutron capture reactions (the r-process) is a longstanding astrophysical problem. Recent analyses of elemental abundances for extremely metal-poor stars shed light on the elemental abundances of individual supernovae. Comparison of the abundance distributions of some extremely metal-poor stars with those of the best-observed supernova SN 1987A clearly indicates that the overabundances of barium and strontium found in SN 1987A that have been ascribed to the slow neutron capture process must be results of r-process nucleosynthesis. The mass of freshly synthesized barium in SN 1987A is estimated to be 6x10^-6 solar mass based on the observed surface abundance and detailed hydrodynamical models for this supernova. These new findings lead to the conclusion that 20 solar mass stars, one of which is the progenitor star of SN 1987A, are the predominant production sites for r-process elements in the Galaxy and the r-process element donors for notable neutron-capture-rich giant stars, CS22892-052 and CS31082-001.

  5. Adsorption structure and doping effect of azidotrimethyltin on graphene , S.N. Yang b

    E-Print Network [OSTI]

    Kim, Sehun

    Adsorption structure and doping effect of azidotrimethyltin on graphene J. Choi a , S.N. Yang b , K Graphene Chemical functionalization Synchrotron Photoemission spectroscopy a b s t r a c t The adsorption demonstrate the variation of characteristic of graphene induced by the chemical functionalized molecule as we

  6. SnO2 Filled Mesoporous Tin Phosphate High Capacity Negative Electrode for Lithium Secondary Battery

    E-Print Network [OSTI]

    Cho, Jaephil

    SnO2 Filled Mesoporous Tin Phosphate High Capacity Negative Electrode for Lithium Secondary Battery insulators, and optics.1-6 On the other hand, their applications to electrode materials in lithium secondary batteries have received little attention because of the very limited candidates.7,8 Recently

  7. Hard templating synthesis of mesoporous and nanowire SnO2 lithium battery anode materials

    E-Print Network [OSTI]

    Cho, Jaephil

    Hard templating synthesis of mesoporous and nanowire SnO2 lithium battery anode materials Hyesun materials for lithium batteries were prepared using KIT-6 and SBA-15 SiO2 templates as an anode material for lithium batteries due to its high capacity (>600 mAh gÀ1 ) compared with graphite

  8. Branched CNT@SnO2 nanorods@carbon hierarchical heterostructures for lithium ion

    E-Print Network [OSTI]

    Qi, Limin

    highly reversible lithium storage behavior and excellent rate capability. The reversible capacity diffusivity and electronic conductivity, which is unfavorable for its applications in high-power devices. Designing hybrid materials of SnO2 nanostructures with carbon-based materials with desirable structures

  9. Dopant-driven Nanostructured Loose-Tube SnO2 Architectures: Alternative Electrocatalyst Supports

    E-Print Network [OSTI]

    Boyer, Edmond

    and specific surface area measurements as well as accelerated corrosion tests and electrochemical measurements lithium ion batteries1, 2 , dye-sensitized solar cells3,4 to sensors5 and optoelectronics6 . Recently, Sn the corrosion of conventional carbon support materials. This corrosion leads to consumption of carbon

  10. Galactic Twins of the Nebula Around SN 1987A: Hints that LBVs may be supernova progenitors

    E-Print Network [OSTI]

    Nathan Smith

    2007-05-21T23:59:59.000Z

    I discuss outstanding questions about the formation of the ring nebula around SN1987A and some implications of similar ring nebulae around Galactic B supergiants. There are notable obstacles for the formation of SN1987A's bipolar nebula through interacting winds in a transition from a red supergiant to a blue supergiant. Instead, several clues hint that the nebula may have been ejected in an LBV-like event. In addition to the previously known example of Sher25, there are two newly-discovered Galactic analogs of SN1987A's ringed nebula. Of these three Galactic analogs around blue supergiants, two (Sher25 and SBW1) have chemical abundances indicating that they have not been through a red supergiant phase, and the remaining ringed bipolar nebula surrounds a luminous blue variable (HD168625). Although SK-69 202's initial mass of 20 Msun is lower than those atributed to most LBVs, it is not far off, and the low-luminosity end of the LBV phenomenon is not well defined. Furthermore, HD168625's luminosity indicates an initial mass of only 25 Msun, that of SBW1 is consistent with 20 Msun, and there is a B[e] star in the SMC with an initial mass of 20 Msun that experienced an LBV outburst in the 1990s. These similarities may be giving us important clues about Sk-69 202's pre-SN evolution and the formation mechanism of its nebula.

  11. Dynamical deformation effects in subbarrier fusion of {sup 64}Ni+{sup 132}Sn

    SciTech Connect (OSTI)

    Umar, A. S.; Oberacker, V. E. [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)

    2006-12-15T23:59:59.000Z

    We show that dynamical deformation effects play an important role in fusion reactions involving the {sup 64}Ni nucleus, in particular the {sup 64}Ni+{sup 132}Sn system. We calculate fully microscopic interaction potentials and the corresponding subbarrier fusion cross-sections.

  12. Uniform hierarchical SnS microspheres: Solvothermal synthesis and lithium ion storage performance

    SciTech Connect (OSTI)

    Fang, Zhen, E-mail: fzfscn@mail.ahnu.edu.cn; Wang, Qin; Wang, Xiaoqing; Fan, Fan; Wang, Chenyan; Zhang, Xiaojun

    2013-11-15T23:59:59.000Z

    Graphical abstract: - Highlights: • Uniform hierarchical SnS microspheres via solvothermal reaction. • The formation process was investigated in detail. • The obtained hierarchical SnS microspheres exhibit superior capacity (1650 mAh g{sup ?1}) when used as lithium battery for the hierarchical microsphere structure. - Abstract: Hierarchical SnS microspheres have been successfully synthesized by a mild solvothermal process using poly(vinylpyrrolidone) as surfactant in this work. The morphology and composition of the microspheres were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The influence of reaction parameters, such as sulfur sources, reaction temperature and the concentration of PVP, on the final morphology of the products are investigated. On the basis of time-dependent experiments, the growth mechanism has also been proposed. The specific surface area of the 3D hierarchitectured SnS microspheres were investigated by using nitrogen adsorption and desorption isotherms. Lithium ion storage performances of the synthesized materials as anodes for Lithium-ion battery were investigated in detail and it exhibits excellent electrochemical properties.

  13. Atmospheric Pressure Deposition of Fluorinedoped SnO2 Thin Films from Organotin Fluorocarboxylate Precursors. 

    E-Print Network [OSTI]

    Mahon, Mary F; Molloy, Kieran C; Stanley, Joanne E; Rankin, David W H; Robertson, Heather E; Johnston, Blair F

    2005-01-01T23:59:59.000Z

    Nine organotin fluorocarboxylates RnSnO2CRf (n = 3, R = Bu, Rf = CF3, C2F5, C3F7, C7F15; R = Et, Rf = CF3, C2F5; R = Me, Rf = C2F5; n = 2, R =Me, Rf = CF3) have been synthesised; key examples have been used to deposit ...

  14. Effect of Sn and Ca doping on the corrosion of Pb anodes in lead acid batteries

    E-Print Network [OSTI]

    Popov, Branko N.

    Effect of Sn and Ca doping on the corrosion of Pb anodes in lead acid batteries Dragan Slavkova of lead anodes used in lead acid batteries. However, one drawback of these materials is their increased reserved. Keywords: Corrosion; Pb anodes; Lead acid batteries; Doping tin; Calcium 1. Introduction

  15. MobiSN: Semantics-based Mobile Ad Hoc Social Network Framework

    E-Print Network [OSTI]

    Li, Juan "Jen"

    MobiSN: Semantics-based Mobile Ad Hoc Social Network Framework Juan Li Department of Computer.khan@ndsu.edu Abstract--Mobile ad hoc social networks are self-configuring social networks that connect users using mobile devices, such as laptops, PDAs, and cellular phones. These social networks facilitate users

  16. The peculiar balmer decrement of SN 2009ip: Constraints on circumstellar geometry

    SciTech Connect (OSTI)

    Levesque, Emily M.; Stringfellow, Guy S.; Bally, John; Keeney, Brian A. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado 389-UCB, Boulder, CO 80309 (United States); Ginsburg, Adam G., E-mail: Emily.Levesque@colorado.edu [European Southern Observatory, ESO Headquarters, Karl-Schwarzschild-Strasse 2, D-95748 Garching bei München (Germany)

    2014-01-01T23:59:59.000Z

    We present optical and near-IR spectroscopic observations of the luminous blue variable SN 2009ip during its remarkable photometric evolution of 2012. The spectra sample three key points in the SN 2009ip light curve, corresponding to its initial brightening in August (2012-A) and its dramatic rebrightening in early October (2012-B). Based on line fluxes and velocities measured in our spectra, we find a surprisingly low I(H?)/I(H?) ratio (?1.3-1.4) in the 2012-B spectra. Such a ratio implies either a rare Case B recombination scenario where H?, but not H?, is optically thick, or an extremely high density for the circumstellar material of n{sub e} > 10{sup 13} cm{sup –3}. The H? line intensity yields a minimum radiating surface area of ?20,000 AU{sup 2} in H? at the peak of SN 2009ip's photometric evolution. Combined with the nature of this object's spectral evolution in 2012, a high circumstellar density and large radiating surface area imply the presence of a thin disk geometry around the central star (and, consequently, a possible binary companion), suggesting that the observed 2012-B rebrightening of SN 2009ip can be attributed to the illumination of the disk's inner rim by fast-moving ejecta produced by the underlying events of 2012-A.

  17. Radio and X-rays From SN 2013df Enlighten Progenitors of Type IIb Supernovae

    E-Print Network [OSTI]

    Kamble, Atish; Soderberg, Alicia M; Chakraborti, Sayan; Fransson, Claes; Chevalier, Roger; Powell, Diana; Milisavljevic, Dan; Parrent, Jerod; Bietenholz, Michael

    2015-01-01T23:59:59.000Z

    We present radio and X-ray observations of the nearby Type IIb Supernova 2013df in NGC4414 from 10 to 250 days after the explosion. The radio emission showed a peculiar soft-to-hard spectral evolution. We present a model in which inverse Compton cooling of synchrotron emitting electrons can account for the observed spectral and light curve evolution. A significant mass loss rate, $\\dot{M} \\approx 8 \\times 10^{-5}\\,\\rm M_{\\odot}/yr$ for a wind velocity of 10 km/s, is estimated from the detailed modeling of radio and X-ray emission, which are primarily due to synchrotron and bremsstrahlung, respectively. We show that SN 2013df is similar to SN 1993J in various ways. The shock wave speed of SN 2013df was found to be average among the radio supernovae; $v_{sh}/c \\sim 0.07$. We did not find any significant deviation from smooth decline in the light curve of SN 2013df. One of the main results of our self-consistent multiband modeling is the significant deviation from energy equipartition between magnetic fields and...

  18. Study of Sn-Coated Graphite as Anode Material for Secondary Lithium-Ion Batteries

    E-Print Network [OSTI]

    Popov, Branko N.

    Study of Sn-Coated Graphite as Anode Material for Secondary Lithium-Ion Batteries Basker Sandia National Laboratories, Albuquerque, New Mexico, USA Tin-graphite composites have been developed as an alternate anode material for Li-ion batteries using an autocatalytic deposition technique. The specific

  19. Wavelength dependence of prepulse laser beams on EUV emission from CO2 reheated Sn plasma

    E-Print Network [OSTI]

    Harilal, S. S.

    Wavelength dependence of prepulse laser beams on EUV emission from CO2 reheated Sn plasma J. R. The expanding plume was then reheated by a 35 ns CO2 laser operating at 10.6 m. The role of prepulse wavelength, Tanaka et al.11 demonstrated the advantages of using a CO2 laser for generating higher CE. The CO2 LPP

  20. Direct band gap optical emission from Ge islands grown on relaxed Si{sub 0.5}Ge{sub 0.5}/Si (100) substrate

    SciTech Connect (OSTI)

    Aluguri, R.; Manna, S.; Ray, S. K., E-mail: physkr@phy.iitkgp.ernet.in [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2014-01-07T23:59:59.000Z

    Strained Ge islands have been grown on fully relaxed Si{sub 0.5}Ge{sub 0.5} substrate by pulsed laser ablation technique. The formation of strained Ge islands has been found for film with higher thickness following Stranski–Krastanov growth mechanism. The variation of strain with changing Ge layer thickness has been analyzed using Raman spectroscopy and high-resolution X-ray diffraction techniques. X-ray photoelectron spectra have shown the absence of any Si-Ge intermixing and oxidation of Ge films. A strong no-phonon photoluminescence emission from Ge islands has been observed, showing the superior optical characteristics of the islands grown on relaxed substrate.

  1. INFLUENCE OF SUBSTRATE OFF-CUT ON THE DEFECT STRUCTURE IN RELAXED GRADED Si-Ge/Si LAYERS

    E-Print Network [OSTI]

    INFLUENCE OF SUBSTRATE OFF-CUT ON THE DEFECT STRUCTURE IN RELAXED GRADED Si-Ge/Si LAYERS SRIKANTH B and Engineering, University of California, Los Angeles, CA 90095. ABSTRACT Relaxed graded Si-Ge/Si layers can of these applications requires a different final Ge concentration in the graded Si-Ge layer. With increasing Ge content

  2. GE & AE Extension Request Form, Version 11, Feb 2013, JC Program Change General English or Academic English

    E-Print Network [OSTI]

    Escher, Christine

    GE & AE Extension Request Form, Version 11, Feb 2013, JC Program Change ­ General English of GE do you wish to request? 1 2 3 4 (GE sessions are 5 weeks) How many GE hours do you wish to take ______________________________________________ Date _________________ #12;GE & AE Extension Request Form, Version 11, Feb 2013, JC Please submit

  3. Time-resolved photoluminescence from self-assembled Ge(Si) islands in multilayer SiGe/Si and SiGe/SOI structures

    SciTech Connect (OSTI)

    Yablonskiy, A. N., E-mail: yablonsk@ipm.sci-nnov.ru; Baidakova, N. A. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)] [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Novikov, A. V. [Lobachevskyi University of Nizhni Novgorod, Physical-Technical Research Institute (Russian Federation)] [Lobachevskyi University of Nizhni Novgorod, Physical-Technical Research Institute (Russian Federation); Lobanov, D. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)] [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2013-11-15T23:59:59.000Z

    The results of a study of the spectral and temporal characteristics of the photoluminescence (PL) from multilayer structures with self-assembled Ge(Si) islands grown on silicon and 'silicon-on-insulator' substrates in relation to temperature and the excitation-light wavelength are presented. A substantial increase in island-related PL intensity is observed for structures with Ge(Si) islands grown on silicon substrates upon an increase in temperature from 4 to 70 K. This increase is due to the diffusion of nonequilibrium carriers from the silicon substrate into the active layer with the islands. In this case, a slow component with a characteristic time of {approx}100 ns appears in the PL rise kinetics. At the same time, no slow component in the PL rise kinetics and no rise in the PL intensity with increasing temperature are observed for structures grown on 'silicon-on-insulator' substrates, in which the active layer with the islands is insulated from the silicon substrate. It is found that absorption of the excitation light in the islands and SiGe wetting layers mainly contributes to the excitation of the PL signal from the islands under sub-bandgap optical pump conditions.

  4. Gigantic uphill diffusion during self-assembled growth of Ge quantum dots on strained SiGe sublayers

    SciTech Connect (OSTI)

    Valakh, M. Ya.; Lytvyn, P. M.; Nikolenko, A. S.; Strelchuk, V. V. [V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, pr. Nauki 45, 03680 Kyiv (Ukraine); Krasilnik, Z. F.; Lobanov, D. N.; Novikov, A. V. [Institute for Physics of Microstructures, RAS, GSP-105, Nizhny Novgorod 603950 (Russian Federation)

    2010-04-05T23:59:59.000Z

    Raman spectroscopy and atomic-force microscopy were applied to study the morphology of nanoislands grown on strained Si{sub 1-x}Ge{sub x} sublayers. It was shown that the growth of nanoislands on strained Si{sub 1-x}Ge{sub x} sublayer not only induces the effect of their spatial ordering but also enhances the role of interdiffusion processes. Unusual high island volume increase during the epitaxy is explained by anomalous strong material diffusion from the sublayer into the islands, induced by nonuniform field of elastic strains.

  5. THE PROGENITOR MASS OF SN 2011dh FROM STELLAR POPULATION ANALYSIS

    SciTech Connect (OSTI)

    Murphy, Jeremiah W.; Jennings, Zachary G.; Williams, Benjamin; Dalcanton, Julianne J. [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Dolphin, Andrew E., E-mail: jmurphy@astro.washington.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 E. Hermans Road, Tucson, AZ 85706 (United States)

    2011-11-20T23:59:59.000Z

    Using Hubble Space Telescope photometry, we characterize the age of the stellar association in the vicinity of supernova (SN) 2011dh and use it to infer the zero-age main-sequence mass (M{sub ZAMS}) of the progenitor star. We find two distinct and significant star formation (SF) events with ages of <6 and 17{sup +3}{sub -4} Myr, and the corresponding M{sub ZAMS} are >29 and 13{sup +2}{sub -1} M{sub Sun }, respectively. These two bursts represent 18{sup +4}{sub -9}% (young) and 64{sup +10}{sub -14}% (old) of the total SF in the last 50 Myr. Adopting these fractions as probabilities suggests that the most probable M{sub ZAMS} is 13{sup +2}{sub -1} M{sub Sun }. These results are most sensitive to the luminosity function along the well-understood main sequence (MS) and are less sensitive to uncertain late-stage stellar evolution. Therefore, they stand even if the progenitor suffered disruptive post-MS evolution (e.g., eruptive mass loss or binary Roche-lobe overflow). Progenitor identification will help to further constrain the appropriate population. Even though pre-explosion images show a yellow supergiant (YSG) at the site of the SN, panchromatic SN light curves suggest a more compact star as the progenitor. In spite of this, our results suggest an association between the YSG and the SN. Not only was the star located at the SN site, but reinforcing an association, the star's bolometric luminosity is consistent with the final evolutionary stage of the 17 Myr old starburst. If the YSG disappears, then M{sub ZAMS} = 13{sup +2}{sub -1} M{sub Sun }, but if it persists, then our results allow the possibility that the progenitor was an unseen star of >29 M{sub Sun }.

  6. HII Region Metallicity Constraints Near the Site of the Strongly Lensed Supernova "SN Refsdal" at Redshift 1.49

    E-Print Network [OSTI]

    Yuan, T -T; Kewley, L J

    2015-01-01T23:59:59.000Z

    We present the local HII region metallicity near the site of the recently discovered multiply lensed supernova (SN; "SN Refsdal") at redshift 1.49. "SN Refsdal" is located at the outer spiral arm ($\\sim$7 kpc) of the lensed host galaxy, which we have previously reported to exhibit a steep negative galactocentric metallicity gradient. Based on our updated near-infrared integral field spectroscopic data, the gas-phase metallicity averaged in an intrinsic radius of $\\sim$ 550 pc surrounding an HII region $\\sim$ 200 pc away from the SN site is 12 + log(O/H)$_{\\rm PP04N2}$ $\\le$ 8.67. The metallicity averaged over nine HII regions at similar galactocentric distances ($\\sim$5-7 kpc) as "SN Refsdal" is constrained to be 12 + log(O/H)$_{\\rm PP04N2}$ $\\le$ 8.11. Given the fortuitous discovery of "SN Refsdal" in an advantageously lensed face-on spiral, this is the first observational constraint on the local metallicity environment of an SN site at redshift $z>1$.

  7. Growth of a Au-Ni-Sn intermetallic compound on the solder-substrate interface after aging

    SciTech Connect (OSTI)

    Minor, Andrew M.; Morris, J.W., Jr.

    1999-12-16T23:59:59.000Z

    Au/Ni metallization has become increasingly common in microelectronic packaging when Cu pads are joined with Pb-Sn solder. The outermost Au layer serves to protect the pad from corrosion and oxidation and the Ni layer provides a diffusion barrier to inhibit detrimental growth of Cu-Sn intermetallics. As a result of reflowing eutectic Pb-Sn on top of Au/Ni metallization, the as-solidified joints have AuSn{sub 4} precipitates distributed throughout the bulk of the solder joint, and Ni{sub 3}Sn{sub 4} intermetallics at the interface. Recent work has shown that the Au-Sn redeposits onto the interface during aging, compromising the strength of the joint. The present work shows that the redeposited intermetallic layer is a ternary compound with stoichiometry Au{sub 0.5}Ni{sub 0.5}Sn{sub 4}. The growth of this intermetallic layer was investigated, and results show that the ternary compound is observed to grow after as little as 3 hours at 150 C and after 3 weeks at 150 C has grown to a thickness of 10 {micro}m. Additionally, methods for inhibiting the growth of the ternary layer were investigated and it was determined that multiple reflows, both with and without additional aging can substantially limit the thickness of the ternary layer.

  8. Inhibitive formation of nanocavities by introduction of Si atoms in Ge nanocrystals produced by ion implantation

    SciTech Connect (OSTI)

    Cai, R. S.; Shang, L.; Liu, X. H.; Zhang, Y. J. [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308 Ningxia Road, Qingdao 266071 (China); Wang, Y. Q., E-mail: yqwang@qdu.edu.cn, E-mail: barba@emt.inrs.ca [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308 Ningxia Road, Qingdao 266071 (China); College of Physics Science, Qingdao University, No. 308 Ningxia Road, Qingdao 266071 (China); Ross, G. G.; Barba, D., E-mail: yqwang@qdu.edu.cn, E-mail: barba@emt.inrs.ca [INRS-Énergie, Matériaux et Télécommunications, 1650 boulevard Lionel-Boulet, Varennes Québec J3X 1S2 (Canada)

    2014-05-28T23:59:59.000Z

    Germanium nanocrystals (Ge-nc) were successfully synthesized by co-implantation of Si and Ge ions into a SiO{sub 2} film thermally grown on (100) Si substrate and fused silica (pure SiO{sub 2}), respectively, followed by subsequent annealing at 1150?°C for 1?h. Transmission electron microscopy (TEM) examinations show that nanocavities only exist in the fused silica sample but not in the SiO{sub 2} film on a Si substrate. From the analysis of the high-resolution TEM images and electron energy-loss spectroscopy spectra, it is revealed that the absence of nanocavities in the SiO{sub 2} film/Si substrate is attributed to the presence of Si atoms inside the formed Ge-nc. Because the energy of Si-Ge bonds (301?kJ·mol{sup ?1}) are greater than that of Ge-Ge bonds (264?kJ·mol{sup ?1}), the introduction of the Si-Ge bonds inside the Ge-nc can inhibit the diffusion of Ge from the Ge-nc during the annealing process. However, for the fused silica sample, no crystalline Si-Ge bonds are detected within the Ge-nc, where strong Ge outdiffusion effects produce a great number of nanocavities. Our results can shed light on the formation mechanism of nanocavities and provide a good way to avoid nanocavities during the process of ion implantation.

  9. 7-GeV Advanced Photon Source Conceptual Design Report

    SciTech Connect (OSTI)

    Not Available

    1987-04-01T23:59:59.000Z

    During the past decade, synchrotron radiation emitted by circulating electron beams has come into wide use as a powerful, versatile source of x-rays for probing the structure of matter and for studying various physical processes. Several synchrotron radiation facilities with different designs and characteristics are now in regular operation throughout the world, with recent additions in this country being the 0.8-GeV and 2.5-GeV rings of NSLS at Brookhaven National Laboratory. However, none of the operating facilities has been designed to use a low-emittance, high-energy stored beam, together with modern undulator devices, to produce a large number of hard x-ray beams of extremely high brilliance. This document is a proposal to the Department of Energy to construct and operate high-energy synchrotron radiation facility at Argonne National Laboratory. We have now chosen to set the design energy of this facility at 7.0 GeV, with the capability to operate at up to 7.5 GeV.

  10. Nucleon Form Factors experiments with 12 GeV CEBAF

    SciTech Connect (OSTI)

    Wojtsekhowski, Bogdan

    2008-11-01T23:59:59.000Z

    A number of precision form factor experiments at high momentum transfer will be performed with the 11 GeV electron beam of CEBAF. We review the approved proposals and the conceptual schemes of several new suggestions. Form factor data will serve as a major input for the construction of a tomographic image of the nucleon.

  11. GeV C. W. electron microtron design report

    SciTech Connect (OSTI)

    Not Available

    1982-05-01T23:59:59.000Z

    Rising interest in the nuclear physics community in a GeV C.W. electron accelerator reflects the growing importance of high-resolution short-range nuclear physics to future advances in the field. In this report major current problems are reviewed and the details of prospective measurements which could be made with a GeV C.W. electron facility are discussed, together with their impact on an understanding of nuclear forces and the structure of nuclear matter. The microtron accelerator has been chosen as the technology to generate the electron beams required for the research discussed because of the advantages of superior beam quality, low capital and operating cost and capability of furnishing beams of several energies and intensities simultaneously. A complete technical description of the conceptual design for a 2 GeV double-sided C.W. electron microtron is presented. The accelerator can furnish three beams with independently controlled energy and intensity. The maximum current per beam is 100 ..mu..amps. Although the precise objective for maximum beam energy is still a subject of debate, the design developed in this study provides the base technology for microtron accelerators at higher energies (2 to 6 GeV) using multi-sided geometries.

  12. Structural Changes in Vitreous GeSe4 under Pressure

    SciTech Connect (OSTI)

    Skinner L. B.; Parise J.; Benmore, C.J,; Antao, S.; Soignard, E.; Amin, S.A.; Bychkov, E.; Rissi, E. and Yarger, J.L.

    2011-11-21T23:59:59.000Z

    High-energy X-ray diffraction experiments have been performed on GeSe{sub 4} glass up to pressures of 8.6 GPa, and the equation of state has been measured up to 10 GPa. The X-ray structure factors reveal a decrease in the first sharp diffraction peak intensity and broadening with pressure, which signifies a break-up of the intermediate range order in the glass. In contrast, the principal peak in the structure factor shows an increase in intensity and a sharpening with pressure, which is attributed to an increase in extended range order and coherence of the compacted units. The average nearest neighbor coordination number is found to remain constant in GeSe{sub 4} glass (within experimental error) over the pressure range measured. This is in contrast with the gradual increase found in GeSe{sub 2} glass. Rather, in GeSe{sub 4} glass the densification mechanism is shown to be associated with large inward shifts of the second neighbor and higher coordination shells. These features appear as additional correlations at 3.3 and 5.3 {angstrom} in the differences taken between adjacent pair distribution functions with increasing pressure.

  13. The JLAB 12 GeV Energy Upgrade of CEBAF

    SciTech Connect (OSTI)

    Harwood, Leigh H. [JLAB

    2013-12-01T23:59:59.000Z

    This presentation should describe the progress of the 12GeV Upgrade of CEBAF at Jefferson Lab. The status of the upgrade should be presented as well as details on the construction, procurement, installation and commissioning of the magnet and SRF components of the upgrade.

  14. Demand Response Performance of GE Hybrid Heat Pump Water Heater

    SciTech Connect (OSTI)

    Widder, Sarah H.; Parker, Graham B.; Petersen, Joseph M.; Baechler, Michael C.

    2013-07-01T23:59:59.000Z

    This report describes a project to evaluate and document the DR performance of HPWH as compared to ERWH for two primary types of DR events: peak curtailments and balancing reserves. The experiments were conducted with GE second-generation “Brillion”-enabled GeoSpring hybrid water heaters in the PNNL Lab Homes, with one GE GeoSpring water heater operating in “Standard” electric resistance mode to represent the baseline and one GE GeoSpring water heater operating in “Heat Pump” mode to provide the comparison to heat pump-only demand response. It is expected that “Hybrid” DR performance, which would engage both the heat pump and electric elements, could be interpolated from these two experimental extremes. Signals were sent simultaneously to the two water heaters in the side-by-side PNNL Lab Homes under highly controlled, simulated occupancy conditions. This report presents the results of the evaluation, which documents the demand-response capability of the GE GeoSpring HPWH for peak load reduction and regulation services. The sections describe the experimental protocol and test apparatus used to collect data, present the baselining procedure, discuss the results of the simulated DR events for the HPWH and ERWH, and synthesize key conclusions based on the collected data.

  15. Demonstration of 2nd Generation Ducted GE "Brillion" Hybrid Water

    E-Print Network [OSTI]

    sharing partners. #12;Project Synopsis Evaluate the performance and demand response (DR) of the Gen II GE/frequency response) in the PNW and nationwide (Lu et al, 2011; Diao et al 2012) The demand response characteristics Participants Project Sponsors: DOE Building America Program/Bonneville Power Administration Contractor: PNNL

  16. Extraction of large valence-band energy offsets and comparison to theoretical values for strained-Si/strained-Ge type-II heterostructures on relaxed SiGe substrates

    E-Print Network [OSTI]

    Teherani, James T.

    Metal-oxide-semiconductor capacitors were fabricated on type-II staggered gap strained-Si/strained-Ge heterostructures epitaxially grown on relaxed SiGe substrates of various Ge fractions. Quasistatic quantum-mechanical ...

  17. Two-stage epitaxial growth of vertically-aligned SnO2 nano-rods on(001) ceria

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Solovyov, Vyacheslav F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wu, Li-jun [Brookhaven National Lab. (BNL), Upton, NY (United States); Rupich, Martin W. [American Superconductor, Devens, MA (United States); Sathyamurthy, Srivatsan [American Superconductor, Devens, MA (United States); Li, Xiaoping [American Superconductor, Devens, MA (United States); Li, Qiang [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-12-01T23:59:59.000Z

    Growth of high-aspect ratio oriented tin oxide, SnO2, nano-rods is complicated by a limited choice of matching substrates. We show that a (001) cerium oxide, CeO2, surface uniquely enables epitaxial growth of tin-oxide nano-rods via a two-stage process. First, (100) oriented nano-wires coat the ceria surface by lateral growth, forming a uniaxially-textured SnO2 deposit. Second, vertical SnO2nano-rods nucleate on the deposit by homoepitaxy. We demonstrate growth of vertically oriented 1-2 ?m long nano-rods with an average diameter of ?20 nm.

  18. Near-Infrared Photoluminescence Enhancement in Ge/CdS and Ge/ZnS Core/Shell Nanocrystals: Utilizing IV/II-VI Semiconductor Epitaxy

    SciTech Connect (OSTI)

    Guo, Yijun [Ames Laboratory; Rowland, Clare E [Argonne National Laboratory; Schaller, Richard D [Argonne National Laboratory; Vela, Javier [Ames Laboratory

    2014-08-26T23:59:59.000Z

    Ge nanocrystals have a large Bohr radius and a small, size-tunable band gap that may engender direct character via strain or doping. Colloidal Ge nanocrystals are particularly interesting in the development of near-infrared materials for applications in bioimaging, telecommunications and energy conversion. Epitaxial growth of a passivating shell is a common strategy employed in the synthesis of highly luminescent II–VI, III–V and IV–VI semiconductor quantum dots. Here, we use relatively unexplored IV/II–VI epitaxy as a way to enhance the photoluminescence and improve the optical stability of colloidal Ge nanocrystals. Selected on the basis of their relatively small lattice mismatch compared with crystalline Ge, we explore the growth of epitaxial CdS and ZnS shells using the successive ion layer adsorption and reaction method. Powder X-ray diffraction and electron microscopy techniques, including energy dispersive X-ray spectroscopy and selected area electron diffraction, clearly show the controllable growth of as many as 20 epitaxial monolayers of CdS atop Ge cores. In contrast, Ge etching and/or replacement by ZnS result in relatively small Ge/ZnS nanocrystals. The presence of an epitaxial II–VI shell greatly enhances the near-infrared photoluminescence and improves the photoluminescence stability of Ge. Ge/II–VI nanocrystals are reproducibly 1–3 orders of magnitude brighter than the brightest Ge cores. Ge/4.9CdS core/shells show the highest photoluminescence quantum yield and longest radiative recombination lifetime. Thiol ligand exchange easily results in near-infrared active, water-soluble Ge/II–VI nanocrystals. We expect this synthetic IV/II–VI epitaxial approach will lead to further studies into the optoelectronic behavior and practical applications of Si and Ge-based nanomaterials.

  19. The polygallides: Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub2}.

    SciTech Connect (OSTI)

    Peter, S. C.; Malliakas, C. D.; Nakotte, H.; Kothapilli, K.; Rayaprol, S.; Schultz, A. J.; Kanatzidis, M. G. (Materials Science Division); ( XSD); (Northwestern Univ.); (Jawaharlal Nehru Centre for Adv. Sci. Res.); (New Mexico State Univ.); (Los Alamos Nat. Lab.); (UGC-DAE Consortium for Sci. Res.)

    2012-03-01T23:59:59.000Z

    Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub 2} were obtained from reactions of Yb and Ge in excess liquid gallium. The crystal structure of Yb{sub 3}Ga{sub 7}Ge{sub 3} was refined using X-ray and neutron diffraction data on selected single crystals. Yb{sub 3}Ga{sub 7}Ge{sub 3} crystallizes in the monoclinic space group C2/c with lattice constants a = 12.2261(20) {angstrom}, b = 10.7447(20) {angstrom}, c = 8.4754(17) {angstrom} and {beta} = 110.288(30){sup o} (neutron diffraction data). The crystal structure of Yb{sub 3}Ga{sub 7}Ge{sub 3} is an intergrowth of planar layers of YbGa{sub x}Ge{sub y} and puckered layers of (Ge)n. YbGa{sub 4}Ge{sub 2} crystallizes in a modified PuGa{sub 6} structure type in the tetragonal polar space group I4cm with lattice constants a = b = 5.9874(6) {angstrom} and c = 15.1178(19) {angstrom}. The structure of YbGa{sub 4}Ge{sub 2} is an intergrowth of puckered Ga layers and puckered Ga{sub x}Ge{sub y} layers with Yb atoms residing within the channels formed by the connection of the two layers. Physical properties, resistivity ({rho}), magnetic susceptibility ({chi}) and specific heat (C) were measured for Yb{sub 3}Ga{sub 7}Ge{sub 3}. No magnetic ordering was observed. It was found that at low temperatures, {rho} varied as T{sup 2} and C{alpha}T, indicating Fermi-liquid regime in Yb{sub 3}Ga{sub 7}Ge{sub 3} at low temperatures.

  20. Adsorption of alkali metals on Ge(001)(2×1) surface. |...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    alkali metals on Ge(001)(2×1) surface. Adsorption of alkali metals on Ge(001)(2×1) surface. Abstract: Ab initio total energy calculations have been performed for Na, K...

  1. Large inherent optical gain from the direct gap transition of Ge thin films

    E-Print Network [OSTI]

    Wang, Xiaoxin

    The recent demonstration of Ge-on-Si diode lasers renews the interest in the unique carrier dynamics of Ge involving both direct (?) and indirect (L) valleys. Here, we report a large inherent direct gap optical gain ...

  2. Epitaxial Ge/Il-V Heterostructures : MOCVD growth, characterization, and applications

    E-Print Network [OSTI]

    Bai, Yu, Ph.D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Epitaxial Ge thin films are being investigated for many important roles in next generation microelectronics. Metal-oxide-semiconductor field effect transistors (MOSFETs) utilizing Ge channels have demonstrated dramatic ...

  3. GE Hydro Asia Co Ltd formerly Kvaerner Power Equipment Co Ltd...

    Open Energy Info (EERE)

    GE Hydro Asia Co Ltd formerly Kvaerner Power Equipment Co Ltd Kvaerner Hangfa Jump to: navigation, search Name: GE Hydro Asia Co Ltd (formerly Kvaerner Power Equipment Co., Ltd...

  4. Ferromagnetism in Mn-Implanted Epitaxially Grown Ge on Si(100)

    E-Print Network [OSTI]

    Guchhait, S.

    2011-01-01T23:59:59.000Z

    group-IV-based dilute magnetic semiconductors by electronicMn x Ge 1-x dilute magnetic semiconductor”, Applied Physicsamorphous Ge 1-x Mn x magnetic semiconductor films”, Journal

  5. EA-0389: Proposed 7-GeV Advanced Photon Source, Argonne, Illinois

    Broader source: Energy.gov [DOE]

    This EA evaluates the environmental impacts of a proposal for construction and operation of a 6- to 7-GeV synchrotron radiation source known as the 7-GeV Advanced Photon Source at DOE's Argonne...

  6. 6 GeV LIGHT SOURCE PROJECT COST ESTIMATING PROCEDURE LS-34

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GeV LIGHT SOURCE PROJECT COST ESTIMATING PROCEDURE LS-34 October 23, 1985 YCAVR To maintain uniformity in estimating the cost requirements of the various components of the 6 GeV...

  7. $J/?$, $?(2S)$ Production in pp Collisions at E=510 GeV

    E-Print Network [OSTI]

    Leonard S. Kisslinger; Debasish Das

    2014-10-06T23:59:59.000Z

    This brief report is an extension of studies of $J/\\Psi,\\Psi(2S)$ production in pp collisions at the BNL with E=$\\sqrt{s}$=200 GeV to E=510 GeV at PHENIX.

  8. Postdoctoral Positions: Si/SiGe Quantum Dots and Quantum Computing Eriksson Group

    E-Print Network [OSTI]

    Saffman, Mark

    Postdoctoral Positions: Si/SiGe Quantum Dots and Quantum Computing Eriksson Group Department in the area of Si/SiGe quantum dots and quantum computing. Recent advances in our group include single

  9. Temperature dependent metal-induced lateral crystallization of amorphous SiGe on insulating substrate

    SciTech Connect (OSTI)

    Kanno, Hiroshi; Toko, Kaoru; Sadoh, Taizoh; Miyao, Masanobu [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan)

    2006-10-30T23:59:59.000Z

    Metal-induced lateral crystallization (MILC) of amorphous SiGe films on SiO{sub 2} has been investigated as a function of Ge fraction (0%-100%) and annealing temperature (320-550 deg. C). High temperature annealing (>500 deg. C) caused spontaneous nucleation in amorphous SiGe with a high Ge fraction (>70%). This suppressed the progress of MILC. Spontaneous nucleation was significantly suppressed by lowering the annealing temperature (<400 deg. C). As a result, large poly-SiGe regions (>20 {mu}m) were observed around Ni patterns even for high Ge fractions (>70%). In this way, MILC of amorphous SiGe was achieved for samples with whole Ge fractions (0%-100%)

  10. Commercialization potential of compositionally graded Ge - Si??x?Gex? - Si substrates for solar applications

    E-Print Network [OSTI]

    Goh, Johnathan Jian Ming

    2006-01-01T23:59:59.000Z

    This project considers the potential of Ge - Si??x?Gex? - Si substrates for solar applications. The use of compositionally graded substrates to achieve heterointegration across different materials platforms such as Si, Ge ...

  11. Electron Backscatter Diffraction of a Ge Growth Tip from a Vertical...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of a Ge Growth Tip from a Vertical Gradient Freeze Furnace. Electron Backscatter Diffraction of a Ge Growth Tip from a Vertical Gradient Freeze Furnace. Abstract: The growth-tip...

  12. LIFETIME AND RADIATIVE EFFICIENCY VS DENSITY IN THE STRAIN-CONFINED ELECTRON-HOLE LIQUID IN Ge

    E-Print Network [OSTI]

    Kelso, Susan M.

    2011-01-01T23:59:59.000Z

    electron-hole liquid (SCEHL) in Ge. Sample CR50 was T = 1.9CONFINED ELECTRON-HOLE LIQUID IN Ge Susan M. Kelso and JohnCONFINED ELECTRON-HOLE LIQUID IN Ge Susan M. Kelso and John

  13. SiGe HBT linear-in-dB high dynamic range RF envelope detectors and wideband high linearity amplifiers

    E-Print Network [OSTI]

    Pan, Hsuan-yu

    2010-01-01T23:59:59.000Z

    1.1 SiGe BiCMOS Technology . . . . . . .A Linear-in-dB SiGe HBT Wideband High Dynamic Range RFpower dissapation trade-off between Si BJTs and SiGe HBTs [

  14. Type IIb supernova SN 2011dh: Spectra and photometry from the ultraviolet to the near-infrared

    SciTech Connect (OSTI)

    Marion, G. H.; Kirshner, Robert P.; Foley, Ryan J.; Berlind, Perry; Bieryla, Allyson; Calkins, Michael L.; Challis, Peter; Chornock, Ryan; Esquerdo, Gilbert A.; Falco, Emilio E.; Friedman, Andrew S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Vinko, Jozsef [University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); Bloom, Joshua S. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Chevalier, Roger A. [Astronomy Department, University of Virginia, Charlottesville, VA 22904 (United States); Culliton, Chris; Curtis, Jason L. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Everett, Mark E. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); France, Kevin [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Fransson, Claes [Department of Astronomy, The Oskar Klein Centre, Stockholm University, S-106 91 Stockholm (Sweden); Garnavich, Peter, E-mail: gmarion@cfa.harvard.edu [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); and others

    2014-02-01T23:59:59.000Z

    We report spectroscopic and photometric observations of the Type IIb SN 2011dh obtained between 4 and 34 days after the estimated date of explosion (May 31.5 UT). The data cover a wide wavelength range from 2000 Å in the ultraviolet (UV) to 2.4 ?m in the near-infrared (NIR). Optical spectra provide line profiles and velocity measurements of H I, He I, Ca II, and Fe II that trace the composition and kinematics of the supernova (SN). NIR spectra show that helium is present in the atmosphere as early as 11 days after the explosion. A UV spectrum obtained with the Space Telescope Imaging Spectrograph reveals that the UV flux for SN 2011dh is low compared to other SN IIb. Modeling the spectrum with SYNOW suggests that the UV deficit is due to line blanketing from Ti II and Co II. The H I and He I velocities in SN 2011dh are separated by about 4000 km s{sup –1} at all phases. A velocity gap is consistent with models for a preexplosion structure in which a hydrogen-rich shell surrounds the progenitor. We estimate that the H shell of SN 2011dh is ?8 times less massive than the shell of SN 1993J and ?3 times more massive than the shell of SN 2008ax. Light curves (LCs) for 12 passbands are presented: UVW2, UVM2, UVW1, U, u', B, V, r', i', J, H, and K{sub s} . In the B band, SN 2011dh reached peak brightness of 13.17 mag at 20.0 ± 0.5 after the explosion. The maximum bolometric luminosity of 1.8 ± 0.2 × 10{sup 42} erg s{sup –1} occurred ?22 days after the explosion. NIR emission provides more than 30% of the total bolometric flux at the beginning of our observations, and the NIR contribution increases to nearly 50% of the total by day 34. The UV produces 16% of the total flux on day 4, 5% on day 9, and 1% on day 34. We compare the bolometric LCs of SN 2011dh, SN 2008ax, and SN 1993J. The LC are very different for the first 12 days after the explosions, but all three SN IIb display similar peak luminosities, times of peak, decline rates, and colors after maximum. This suggests that the progenitors of these SN IIb may have had similar compositions and masses, but they exploded inside hydrogen shells that have a wide range of masses. SN 2011dh was well observed, and a likely progenitor star has been identified in preexplosion images. The detailed observations presented here will help evaluate theoretical models for this SN and lead to a better understanding of SN IIb.

  15. Ris-M-2737 ' / > ^ ' ' . / , / -THE PHASES OF Pb/Ge(lll)

    E-Print Network [OSTI]

    #12;Risø-M-2737 ' / > ^ ' ' . / , / - THE PHASES OF Pb/Ge(lll): A SURFACE X-RAY DIFFRACTION STUDY of a chemisorbed overlayer of Pb on the Ge(lll) surface. Three phases of Pb/Ge(lll) exist in the monolayer regime: the a- and B-phases with a V3xV3R30° unit cell, and a high-temperature IX1 phase. In the 1X1 phase of Pb/Ge

  16. Directional correlation of [gamma] transitions in [sup 72]Ge following the decay of [sup 72]Ga

    SciTech Connect (OSTI)

    Landulfo, E.; Saxena, R.N.; Zamboni, C.B.; Lapolli, A.L. (Instituto de Pesquisas Energeticas e Nucleares, IPEN-Comissao Nacional de Energia Nuclear de Brasil, Sao Paulo, Sao Paulo (Brazil))

    1994-08-01T23:59:59.000Z

    Directional correlations of coincident gamma transitions in [sup 72]Ge have been measured following the [beta][sup [minus

  17. MECHANICS OF RELAXING SiGe ISLANDS ON A VISCOUS GLASS , J. Liang1

    E-Print Network [OSTI]

    Suo, Zhigang

    MECHANICS OF RELAXING SiGe ISLANDS ON A VISCOUS GLASS R. Huang1 , H. Yin2 , J. Liang1 , J.C. Sturm2, a SiGe thin film, a glass layer, and a Si wafer. The SiGe film is a perfect crystal, and is under biaxial compression. Pattern the SiGe film into islands. On annealing, the glass flows and the islands

  18. Studies of Nb3Sn Strands Based on the Restacked-Rod Process for High-Field Accelerator Magnets Nb3Sn

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barzi, E; Bossert, M; Gallo, G; Lombardo, V; Turrioni, D; Yamada, R; Zlobin, A V

    2012-06-01T23:59:59.000Z

    A major thrust in Fermilab's accelerator magnet R&D program is the development of Nb3Sn wires which meet target requirements for high field magnets, such as high critical current density, low effective filament size, and the capability to withstand the cabling process. The performance of a number of strands with 150/169 restack design produced by Oxford Superconducting Technology was studied for round and deformed wires. To optimize the maximum plastic strain, finite element modeling was also used as an aid in the design. Results of mechanical, transport and metallographic analyses are presented for round and deformed wires.

  19. Why is GeV physics relevant in the age of the LHC?

    SciTech Connect (OSTI)

    Pennington, Michael R. [JLAB

    2014-02-01T23:59:59.000Z

    The contribution that Jefferson Lab has made, with its 6 GeV electron beam, and will make, with its 12 GeV upgrade, to our understanding of the way the fundamental interactions work, particularly strong coupling QCD, is outlined. The physics at the GeV scale is essential even in TeV collisions.

  20. 2D-GE IMAGE SEGMENTATION BASED ON LEVEL-SETS E.A. Mylona a

    E-Print Network [OSTI]

    Athens, University of

    2D-GE IMAGE SEGMENTATION BASED ON LEVEL-SETS E.A. Mylona a , M.A. Savelonas a , D. Maroulis a , M of protein spots in 2D-GE images. The proposed scheme incorporates a protein spot detection stage based both software packages in terms of segmentation performance. Index Terms--2D-GE Images, Protein Spot

  1. Surface Science Letters Self-assembled growth of ordered Ge nanoclusters on

    E-Print Network [OSTI]

    Gao, Hongjun

    Surface Science Letters Self-assembled growth of ordered Ge nanoclusters on the Si(1 1 1)-(7 Â 7-assembled growth of submonolayer Ge on the Si(1 1 1)-(7 Â 7) surface grown by solid phase epitaxy has been studied using scanning tunneling microscopy. Ordered Ge nanoclusters on the surface are formed by the deposition

  2. Distinct local electronic structure and magnetism for Mn in amorphous Si and Ge

    E-Print Network [OSTI]

    Zeng, Li

    2010-01-01T23:59:59.000Z

    Mn-Si (red squares) and Mn-Ge distances (blue circles) d asof the number of Si or Ge nearest neighbours N c ; (c) localthree Mn atoms with different N c in a-Mn 0.094 Ge 0.906 .

  3. Black Ge Based on Crystalline/Amorphous Core/Shell Nanoneedle Arrays

    E-Print Network [OSTI]

    Javey, Ali

    Black Ge Based on Crystalline/Amorphous Core/Shell Nanoneedle Arrays Yu-Lun Chueh,,§,|,# Zhiyong, ROC ABSTRACT Direct growth of black Ge on low-temperature substrates, including plastics and rubber is reported. The material is based on highly dense, crystalline/amorphous core/shell Ge nanoneedle arrays

  4. Defects in Ge and Si caused by 1 MeV Si+ implantation*

    E-Print Network [OSTI]

    Florida, University of

    Defects in Ge and Si caused by 1 MeV Si+ implantation* D. P. Hickeya Department of Materials defect formation and evolution in the 001 Ge and Si wafers implanted with 1 MeV Si+ and 40 keV Si dissolve at the projected range for nonamorphizing implants into Si. However, in Ge, no 311 defect

  5. Formation of Ge nanoclusters on Si(1 1 1)-7 7 surface at high temperature

    E-Print Network [OSTI]

    Gao, Hongjun

    Formation of Ge nanoclusters on Si(1 1 1)-7 · 7 surface at high temperature H.M. Guo, Y.L. Wang, H for publication 17 May 2004 Available online 5 June 2004 Abstract We report on Ge nanocluster formation on Si(1 1 of the Ge clusters are more uniform than those obtained at room temperature due to an increase

  6. Transistor-Based Ge/SOI Photodetector for Integrated Silicon Photonics

    E-Print Network [OSTI]

    Luo, Xi

    2011-01-01T23:59:59.000Z

    11. Y. -H. Kuo, Y. -K. Lee, Y. Ge, S. Ren, J. E. Roth, T. I.Colace and G. Assanto, “Poly-Ge Near-infrared PhotodetectorsMasini and G. Assanto, “Ge on Si p-i-n photodiodes operating

  7. Alloyed junction Ge Esaki diodes on Si substrates realised by aspect ratio trapping

    E-Print Network [OSTI]

    Rommel, Sean

    Alloyed junction Ge Esaki diodes on Si substrates realised by aspect ratio trapping technique D. Pawlik, S. Sieg, S.K. Kurinec, S.L. Rommel, Z. Cheng, J.-S. Park, J. Hydrick and A. Lochtefeld A Ge Esaki diode is demonstrated on Si atop a coalesced epitaxial layer of Ge grown through narrow openings in SiO2

  8. Materials synthesis and investigation of itinerant ferromagnetism in the UCo?-xFex Ge system

    E-Print Network [OSTI]

    Huang, Kevin

    2009-01-01T23:59:59.000Z

    B. UCo 1?x Fe x Ge . . . . . . . . . . . . . 1. Polycrystalvs temperature data of UCo 1?x Fe x Ge from x = 0.0 to x =vs temperature data of UCo 1?x Fe x Ge from x = 0.20 to x =

  9. Ge incorporation inside 4H-SiC during Homoepitaxial growth by chemical vapor

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Ge incorporation inside 4H-SiC during Homoepitaxial growth by chemical vapor deposition. Kassem Ilmenau (Germany) Abstract. In this work, we report on the addition of GeH4 gas during homoepitaxial growth of 4H-SiC by chemical vapour deposition. Ge introduction does not affect dramatically the surface

  10. Room-temperature 1.3 pm electroluminescence from strained Si, -,Ge,/Si quantum wells

    E-Print Network [OSTI]

    Room-temperature 1.3 pm electroluminescence from strained Si, -,Ge,/Si quantum wells Q. Mi, X. Xiao report the first room-temperature 1.3 ,um electroluminescence from strained Sir-,Ge,/Si quantum wells to that from the Sit-,GeX wells. A minimum band offset is required to have effective room

  11. GE & AE Extension Request Form, Version 8, Feb 2013, JC Program Extension

    E-Print Network [OSTI]

    Escher, Christine

    GE & AE Extension Request Form, Version 8, Feb 2013, JC Program Extension General English English (GE) Academic English (AE) 2. Which term will this extension begin? Fall Winter Spring Summer 3 of General English do you wish to request? 1 2 3 4 5 6 (GE sessions are 5 weeks) How many General English

  12. Coexisting Superconductivity and Magnetism in UCoGe Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Coexisting Superconductivity and Magnetism in UCoGe Gregory S. Boebinger, National High Magnetic focused on the coexistence of superconductivity and ferromagnetism, including UGe2, URhGe, and UCoGe. In these materials, superconductivity develops below the ferromagnetic Curie temperature TC without destroying

  13. Crack formation in GaAs heteroepitaxial films on Si and SiGe virtual substrates

    E-Print Network [OSTI]

    Crack formation in GaAs heteroepitaxial films on Si and SiGe virtual substrates V. K. Yang, MAs films grown on Si and SiGe virtual substrates analytically and experimentally. The analytical model­10 Relaxed SiGe graded layers on Si have produced the highest quality GaAs on Si to date for the integration

  14. \\Development, implementation and veri cation of a physics-based Si/SiGe

    E-Print Network [OSTI]

    Paper I \\Development, implementation and veri#12;cation of a physics-based Si/SiGe HBT model and verification of a physics­based Si/SiGe HBT model for millimeter­wave non­ linear circuit simulations. S. Bruce thermal dependence has been developed for Si/SiGe HBTs. The model takes into account several effects

  15. EVOLUTION OF SELF-INTERSTITIALS INDUCED BY ION-IMPLANTATION IN SiGe ALLOYS

    E-Print Network [OSTI]

    Florida, University of

    EVOLUTION OF SELF-INTERSTITIALS INDUCED BY ION-IMPLANTATION IN SiGe ALLOYS By ROBERT T. CROSBY and Astronomy at the University of Aarhus in Denmark provided the utmost quality SiGe structures for my {311 great colleague, supervisor, and friend) grew the B-doped SiGe structures. J. Liu of Varian

  16. High Performance Polycrystalline SiGe Thin Film Transistors Using Al2O3 Gate Insulator

    E-Print Network [OSTI]

    1 High Performance Polycrystalline SiGe Thin Film Transistors Using Al2O3 Gate Insulator Zhonghe as the gate insulator for low temperature (SiGe thin film transistors (TFTs) has been between the Al2O3 and the SiGe channel layer is sufficiently passivated to make Al2O3 a better alternative

  17. Design of a 250-Gbit/s SiGe HBT Electrooptic Modulator

    E-Print Network [OSTI]

    Huang, Zhaoran "Rena"

    Design of a 250-Gbit/s SiGe HBT Electrooptic Modulator Volume 3, Number 5, October 2011 Tuhin Guha.1109/JPHOT.2011.2169658 1943-0655/$26.00 ©2011 IEEE #12;Design of a 250-Gbit/s SiGe HBT Electrooptic: We present a rigorous electrical and optical analysis of a highly scaled, graded- base, SiGe

  18. SiGe/Si superlattice power generators Gehong Zeng, John E. Bowers

    E-Print Network [OSTI]

    Bowers, John

    SiGe/Si superlattice power generators Gehong Zeng, John E. Bowers Department of Electrical 95064 *Corresponding Email: ali@soe.ucsc.edu, phone: (831) 459-3821 Abstract SiGe is one of the best selective emission of hot electrons through thermionic emission. SiGe/Si superlattice structures were grown

  19. Simulation of Si/SiGe Micro-Cooler by Thermal Quadrupoles Method Y. Ezzahri *(a)

    E-Print Network [OSTI]

    Simulation of Si/SiGe Micro-Cooler by Thermal Quadrupoles Method Y. Ezzahri *(a) , S. Dilhaire (a on thermal quadrupoles is presented to model the behavior of a single stage Si/SiGe micro-cooler in AC of the model with experimental reflectometry techniques is also presented. Performance of Si/SiGe micro

  20. SiGe HBT Nonlinear Phase Noise Modeling Sebastien Gribaldo, Laurent Bary and Olivier Llopis

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    SiGe HBT Nonlinear Phase Noise Modeling S´ebastien Gribaldo, Laurent Bary and Olivier Llopis LAAS model of a SiGe bipolar transistor is presented. This model includes nonlinear noise sources and is able phase noise data at different RF power level. Keywords: nonlinear noise, modelling, SiGe PACS: 85.40.Qx