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Sample records for mn ia mo

  1. Determination of the direct double- β -decay Q value of Zr <mn>96mn> and atomic masses of Zr <mn>90mn> <mo>-> <mn>92mn> <mo>,> <mn>94mn> <mo>,> <mn>96mn> and Mo <mn>92mn> <mo>,> <mn>94mn> <mo>-> <mn>98mn> <mo>,> <mn>100mn>

    SciTech Connect (OSTI)

    Gulyuz, K.; Ariche, J.; Bollen, G.; Bustabad, S.; Eibach, M.; Izzo, C.; Novario, S. J.; Redshaw, M.; Ringle, R.; Sandler, R.; Schwarz, S.; Valverde, A. A.

    2015-05-06

    Experimental searches for neutrinoless double-β decay offer one of the best opportunities to look for physics beyond the standard model. Detecting this decay would confirm the Majorana nature of the neutrino, and a measurement of its half-life can be used to determine the absolute neutrino mass scale. Important to both tasks is an accurate knowledge of the Q value of the double-β decay. The LEBIT Penning trap mass spectrometer was used for the first direct experimental determination of the ⁹⁶Zr double-β decay Q value: Qββ=3355.85(15) keV. This value is nearly 7 keV larger than the 2012 Atomic Mass Evaluation [M. Wang et al., Chin. Phys. C 36, 1603 (2012)] value and one order of magnitude more precise. The 3-σ shift is primarily due to a more accurate measurement of the ⁹⁶Zr atomic mass: m(⁹⁶Zr)=95.90827735(17) u. Using the new Q value, the 2νββ-decay matrix element, |M|, is calculated. Improved determinations of the atomic masses of all other zirconium (90-92,94,96Zr) and molybdenum (92,94-98,100Mo) isotopes using both ¹²C₈ and ⁸⁷Rb as references are also reported.

  2. First-Principles Calculations, Electrochemical and X-ray Absorption Studies of Li-Ni-PO4 Surface-Treated xLi2MnO3 (1 x)LiMO2 (M = Mn, Ni, Co) Electrodes for Li-Ion Batteries

    SciTech Connect (OSTI)

    Wolverton, Christopher; Croy, J R; Balasubramanian, M; Kang, Sun-Ho; Lopez-Rivera, C. M.; Thackeray, Michael M.

    2012-01-01

    It has been previously hypothesized that the enhanced rate capability of Li-Ni-PO{sub 4}-treated xLi{sub 2}MnO{sub 3} {center_dot} (1-x)LiMO{sub 2} positive electrodes (M = Mn, Ni, Co) in Li-ion batteries might be associated with a defect Ni-doped Li{sub 3}PO{sub 4} surface structure [i.e., Li{sub 3-2y}Ni{sub y}PO{sub 4} (0 < y < 1)], thereby promoting fast Li{sup +}-ion conduction at the xLi{sub 2}MnO{sub 3} {center_dot} (1-x)LiMO{sub 2} particle surface. In this paper, the solubility of divalent metals (Fe, Mn, Ni, Mg) in {gamma}-Li{sub 3}PO{sub 4} is predicted with the first-principles GGA+U method in an effort to understand the enhanced rate capability. The predicted solubility (x) is extremely small; this finding is consistent with experimental evidence: 1) X-ray diffraction data obtained from Li-Ni-PO{sub 4}-treated xLi{sub 2}MnO{sub 3} {center_dot} (1-x)LiMO{sub 2} electrodes that show that, after annealing at 550 C, a Li{sub 3}PO{sub 4}-like structure forms as a second phase at the electrode particle surface, and 2) X-ray absorption spectroscopy, which indicate that the nickel ions are accommodated in the transition metal layers of the Li{sub 2}MnO{sub 3} component during the annealing process. However, electrochemical studies of Li{sub 3-2y}Ni{sub y}PO{sub 4}-treated xLi{sub 2}MnO{sub 3} {center_dot} (1-x)LiMO{sub 2} electrodes indicate that their rate capability increases as a function of y over the range y = 0 (Li{sub 3}PO{sub 4}) to y = 1 (LiNiPO{sub 4}), strongly suggesting that, at some level, the nickel ions play a role in reducing electrochemical impedance and increasing electrode stability at the electrode particle surface.

  3. DIVERSITY OF TYPE Ia SUPERNOVAE IMPRINTED IN CHEMICAL ABUNDANCES

    SciTech Connect (OSTI)

    Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan); Shigeyama, Toshikazu, E-mail: taku.tsujimoto@nao.ac.jp [Research Center for the Early Universe, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2012-12-01

    A time delay of Type Ia supernova (SN Ia) explosions hinders the imprint of their nucleosynthesis on stellar abundances. However, some occasional cases give birth to stars that avoid enrichment of their chemical compositions by massive stars and thereby exhibit an SN-Ia-like elemental feature including a very low [Mg/Fe] ( Almost-Equal-To - 1). We highlight the elemental feature of Fe-group elements for two low-Mg/Fe objects detected in nearby galaxies, and propose the presence of a class of SNe Ia that yield the low abundance ratios of [Cr, Mn, Ni/Fe]. Our novel models of chemical evolution reveal that our proposed class of SNe Ia (slow SNe Ia) is associated with ones exploding on a long timescale after their stellar birth and give a significant impact on the chemical enrichment in the Large Magellanic Cloud (LMC). In the Galaxy, on the other hand, this effect is unseen due to the overwhelming enrichment by the major class of SNe Ia that explode promptly (prompt SNe Ia) and eject a large amount of Fe-group elements. This nicely explains the different [Cr, Mn, Ni/Fe] features between the two galaxies as well as the puzzling feature seen in the LMC stars exhibiting very low Ca but normal Mg abundances. Furthermore, the corresponding channel of slow SN Ia is exemplified by performing detailed nucleosynthesis calculations in the scheme of SNe Ia resulting from a 0.8 + 0.6 M{sub Sun} white dwarf merger.

  4. Rolling Hills (IA) | Open Energy Information

    Open Energy Info (EERE)

    Rolling Hills (IA) Jump to: navigation, search Name Rolling Hills (IA) Facility Rolling Hills (IA) Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service...

  5. Steamboat IA Geothermal Facility | Open Energy Information

    Open Energy Info (EERE)

    IA Geothermal Facility Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Steamboat IA Geothermal Facility General Information Name Steamboat IA Geothermal Facility...

  6. Formation of voids and secondary-phase precipitates in the Fe-16Cr-15Ni-2Mo-1Mn-Ti-Si steel under high-doze neutron irradiation and during post-irradiation annealing

    SciTech Connect (OSTI)

    Portnykh, I. A. Kozlov, A. V.; Shcherbakov, E. N.; Asiptsov, O. I.

    2009-12-15

    The effect of high-dose neutron irradiation on the structural changes in Fe-16Cr-15Ni-2Mo-1Mn-Ti-Si austenitic steel have been investigated. Samples irradiated at temperatures of 390, 500, and 600{sup o} to damage doses of 46, 86, and 46 dpa, respectively, were analyzed by electron microscopy and dilatometry. The quantitative characteristics of radiation voids and secondary-phase precipitates formed under neutron irradiation are obtained. Their behavior upon heating to 700{sup o}C and annealing at this temperature for 2 h is studied. It is shown that annealing leads to the dissociation of small voids, which is accompanied by the growth of large ones. The secondary-phase precipitates are partially dissolved upon annealing, and their volume fraction decreases.

  7. IA Experts Listing 2014 | Department of Energy

    Office of Environmental Management (EM)

    IA Experts Listing 2014 IA Experts Listing 2014 PDF icon IA Experts Listing January 2014 More Documents & Publications Office of International Affairs Organization Chart PI Organization Chart Office of Policy and International Affairs Organization Chart

  8. Mo-99

    National Nuclear Security Administration (NNSA)

    its project for domestic production of molybdenum-99 (Mo-99) without highly enriched uranium (HEU).

    Mo-99 is the parent isotope of technetium-99m, which is the most widely...

  9. Category:Mason, IA | Open Energy Information

    Open Energy Info (EERE)

    Mason, IA Jump to: navigation, search Go Back to PV Economics By Location Media in category "Mason, IA" The following 16 files are in this category, out of 16 total....

  10. Defining photometric peculiar type Ia supernovae

    SciTech Connect (OSTI)

    Gonzlez-Gaitn, S.; Pignata, G.; Frster, F.; Gutirrez, C. P.; Bufano, F.; Galbany, L.; Hamuy, M.; De Jaeger, T. [Millennium Institute of Astrophysics, Casilla 36-D, Santiago (Chile); Hsiao, E. Y.; Phillips, M. M. [Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena (Chile); Folatelli, G. [Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa 277-8583 (Kavli IPMU, WPI) (Japan); Anderson, J. P., E-mail: sgonzale@das.uchile.cl [European Southern Observatory, Alonso de Crdova 3107, Casilla 19, Santiago (Chile)

    2014-11-10

    We present a new photometric identification technique for SN 1991bg-like type Ia supernovae (SNe Ia), i.e., objects with light curve characteristics such as later primary maxima and the absence of a secondary peak in redder filters. This method is capable of selecting this sub-group from the normal type Ia population. Furthermore, we find that recently identified peculiar sub-types such as SNe Iax and super-Chandrasekhar SNe Ia have photometric characteristics similar to 91bg-like SNe Ia, namely, the absence of secondary maxima and shoulders at longer wavelengths, and can also be classified with our technique. The similarity of these different SN Ia sub-groups perhaps suggests common physical conditions. This typing methodology permits the photometric identification of peculiar SNe Ia in large upcoming wide-field surveys either to study them further or to obtain a pure sample of normal SNe Ia for cosmological studies.

  11. Mo-99

    National Nuclear Security Administration (NNSA)

    NorthStar Medical Radioisotopes to further develop its technology to produce Mo-99 via neutron capture, bringing the total NNSA support to this project to the maximum of 25...

  12. MO: ZL

    Office of Legacy Management (LM)

    II , --fsi2L /~YlO MO: ZL W./O -1 ;3UN 2 2 1984 DeLanr 6/W/f. NE-20 -24 Authorization for Remedial Action at the Seaway Industrial Park and Ashland 0 1 Co. (I) Sites at Tonawanda, 9 NY, and Mallinckrodt Chemical Co., St. Louis, MO Ba 1s J. LaGrone, Eianager Oak Ridge Operations Office 6/20/E We have determined that the subject sites are contaminated with residual NE-20 radioactive material as a result of the Manhattan Engineer District/Atomic ,/"/1. EnergyXommission operations at those

  13. DOE - Office of Legacy Management -- Titus Metals - IA 04

    Office of Legacy Management (LM)

    Titus Metals - IA 04 FUSRAP Considered Sites Site: TITUS METALS ( IA.04 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Waterloo , Iowa IA.04-1 Evaluation Year: 1987 IA.04-2 Site Operations: Extruded uranium billets to produce fuel plates for the Argonaut reactor in June, 1956. IA.04-1 IA.04-2 Site Disposition: Eliminated - Potential for contamination considered remote based on the limited scope of activities at the site and results of

  14. Constraining Cosmic Evolution of Type Ia Supernovae (Journal...

    Office of Scientific and Technical Information (OSTI)

    Constraining Cosmic Evolution of Type Ia Supernovae Citation Details In-Document Search Title: Constraining Cosmic Evolution of Type Ia Supernovae We present the first large-scale...

  15. Constraining Cosmic Evolution of Type Ia Supernovae (Journal...

    Office of Scientific and Technical Information (OSTI)

    Constraining Cosmic Evolution of Type Ia Supernovae Citation Details In-Document Search Title: Constraining Cosmic Evolution of Type Ia Supernovae You are accessing a document...

  16. Flames in Type Ia Supernova: Deflagration-Detonation Transition...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame. Citation Details In-Document Search Title: Flames in Type Ia...

  17. ASTRONOMY AND ASTROPHYSICS Dark Energy, Type Ia supernovae, radiative

    Office of Scientific and Technical Information (OSTI)

    of Oklahoma Univ. of Oklahoma 79 ASTRONOMY AND ASTROPHYSICS Dark Energy, Type Ia supernovae, radiative transfer, Dark Energy, Type Ia supernovae, radiative transfer, The...

  18. New approaches for modeling type Ia supernovae (Conference) ...

    Office of Scientific and Technical Information (OSTI)

    Type Ia supernovae (SNe Ia) are the largest thermonuclearexplosions in the Universe. Their light output can be seen across greatstances and has led to the discovery that the ...

  19. Quantification of corrosion resistance of a new-class of criticality control materials: thermal-spray coatings of high-boron iron-based amorphous metals - Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4

    SciTech Connect (OSTI)

    Farmer, J C; Choi, J S; Shaw, C K; Rebak, R; Day, S D; Lian, T; Hailey, P; Payer, J H; Branagan, D J; Aprigliano, L F

    2007-03-28

    An iron-based amorphous metal, Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} (SAM2X5), with very good corrosion resistance was developed. This material was produced as a melt-spun ribbon, as well as gas atomized powder and a thermal-spray coating. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation. The high boron content of this particular amorphous metal made it an effective neutron absorber, and suitable for criticality control applications. Earlier studies have shown that ingots and melt-spun ribbons of these materials have good passive film stability in these environments. Thermal spray coatings of these materials have now been produced, and have undergone a variety of corrosion testing, including both atmospheric and long-term immersion testing. The modes and rates of corrosion have been determined in the various environments, and are reported here.

  20. IA Blog Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    "always be five years away." For four key clean energy technologies, that clean energy future has already arrived. August 21, 2013 IA Blog Archive ActOnClimate: Secretary...

  1. Type Ia Supernovae Project at NERSC

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

    of star called a white dwarf. The majority of SN Ia explosions occur far away from our galaxy; yet, due to their enormous intrinsic brightness, outshining billions of stars, we can...

  2. IA Blog Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Blog Archive IA Blog Archive RSS December 7, 2015 IA Blog Archive Rise and Shine: Lighting the World with 10 Billion LED Bulbs Launched at COP21 in Paris, the Global Lighting Challenge is a race to deploy 10 billion high-efficiency, high-quality and affordable lighting fixtures and bulbs (like LEDs) around the world. December 1, 2015 Deputy Secretary Sherwood-Randall Co-Chairs the U.S.-Brazil Strategic Energy Dialogue The United States of America and the Federative Republic of Brazil reaffirmed

  3. Improved Distances to Type Ia Supernovae withMulticolor Light...

    Office of Scientific and Technical Information (OSTI)

    Peculiar velocities of SN Ia host galaxies in the rest frame of the Local Group are ... Direct fits of SN Ia that are significantly reddened by dust in their host galaxies ...

  4. IA News Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    News Archive IA News Archive RSS November 23, 2015 Energy Department Announces Six Clean Energy Projects through Partnership with Israel U.S. Department of Energy and Israel's Ministry of National Infrastructure, Energy and Water Resources announce $5.1 million for six newly selected clean energy projects as part of the Binational Industrial Research and Development Energy program. August 5, 2015 Jonathan Elkind Confirmed as Assistant Secretary for International Affairs Mr. Elkind will oversee

  5. The Distant Type Ia Supernova Rate

    DOE R&D Accomplishments [OSTI]

    Pain, R.; Fabbro, S.; Sullivan, M.; Ellis, R. S.; Aldering, G.; Astier, P.; Deustua, S. E.; Fruchter, A. S.; Goldhaber, G.; Goobar, A.; Groom, D. E.; Hardin, D.; Hook, I. M.; Howell, D. A.; Irwin, M. J.; Kim, A. G.; Kim, M. Y.; Knop, R. A.; Lee, J. C.; Perlmutter, S.; Ruiz-Lapuente, P.; Schahmaneche, K.; Schaefer, B.; Walton, N. A.

    2002-05-28

    We present a measurement of the rate of distant Type Ia supernovae derived using 4 large subsets of data from the Supernova Cosmology Project. Within this fiducial sample, which surveyed about 12 square degrees, thirty-eight supernovae were detected at redshifts 0.25--0.85. In a spatially flat cosmological model consistent with the results obtained by the Supernova Cosmology Project, we derive a rest-frame Type Ia supernova rate at a mean red shift z {approx_equal} 0.55 of 1.53 {sub -0.25}{sub -0.31}{sup 0.28}{sup 0.32} x 10{sup -4} h{sup 3} Mpc{sup -3} yr{sup -1} or 0.58{sub -0.09}{sub -0.09}{sup +0.10}{sup +0.10} h{sup 2} SNu(1 SNu = 1 supernova per century per 10{sup 10} L{sub B}sun), where the first uncertainty is statistical and the second includes systematic effects. The dependence of the rate on the assumed cosmological parameters is studied and the redshift dependence of the rate per unit comoving volume is contrasted with local estimates in the context of possible cosmic star formation histories and progenitor models.

  6. Search for surviving companions in type Ia supernova remnants

    SciTech Connect (OSTI)

    Pan, Kuo-Chuan [Physik Department, Universitt Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Ricker, Paul M. [Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Taam, Ronald E., E-mail: kuo-chuan.pan@unibas.ch, E-mail: pmricker@illinois.edu, E-mail: r-taam@northwestern.edu, E-mail: taam@asiaa.sinica.edu.tw [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)

    2014-09-01

    The nature of the progenitor systems of type Ia supernovae (SNe Ia) is still unclear. One way to distinguish between the single-degenerate scenario and double-degenerate scenario for their progenitors is to search for the surviving companions (SCs). Using a technique that couples the results from multi-dimensional hydrodynamics simulations with calculations of the structure and evolution of main-sequence- (MS-) and helium-rich SCs, the color and magnitude of MS- and helium-rich SCs are predicted as functions of time. The SC candidates in Galactic type Ia supernova remnants (Ia SNR) and nearby extragalactic Ia SNRs are discussed. We find that the maximum detectable distance of MS SCs (helium-rich SCs) is 0.6-4 Mpc (0.4-16 Mpc), if the apparent magnitude limit is 27 in the absence of extinction, suggesting that the Large and Small Magellanic Clouds and the Andromeda Galaxy are excellent environments in which to search for SCs. However, only five Ia SNRs have been searched for SCs, showing little support for the standard channels in the singe-degenerate scenario. To better understand the progenitors of SNe Ia, we encourage the search for SCs in other nearby Ia SNRs.

  7. THE ULTRAVIOLET BRIGHTEST TYPE Ia SUPERNOVA 2011de

    SciTech Connect (OSTI)

    Brown, Peter J., E-mail: pbrown@physics.tamu.edu [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)

    2014-11-20

    We present and discuss the ultraviolet (UV)/optical photometric light curves and absolute magnitudes of the TypeIa supernova (SN Ia) 2011de from the Swift Ultraviolet/Optical Telescope. We find it to be the UV brightest SN Ia yet observedmore than a factor of 10 brighter than normal SNe Ia in the mid-ultraviolet. We find that the UV/optical brightness and broad light curve evolution can be modeled with additional flux from the shock of the ejecta hitting a relatively large red giant companion separated by 6 10{sup 13} cm. However, the post-maximum behavior of other UV-bright SNe Ia can also be modeled in a similar manner, including objects with UV spectroscopy or pre-maximum photometry which is inconsistent with this model. This suggests that similar UV luminosities can be intrinsic or caused by other forms of shock interaction. The high velocities reported for SN 2011de make it distinct from the UV-bright ''super-Chandrasekhar'' SNe Ia and the NUV-blue group of normal SNe Ia. SN 2011de is an extreme example of the UV variations in SNe Ia.

  8. Nonuniversal gaugino masses and muong<mo>->2mn>

    SciTech Connect (OSTI)

    Gogoladze, Ilia; Nasir, Fariha; Shafi, Qaisar; n, Cem Salih

    2014-08-11

    We consider two classes of supersymmetric models with nonuniversal gaugino masses at the grand unification scale MGUT in an attempt to resolve the apparent muon g-2 anomaly encountered in the Standard Model. We explore two distinct scenarios, one in which all gaugino masses have the same sign at MGUT, and a second case with opposite sign gaugino masses. The sfermion masses in both cases are assumed to be universal at MGUT. We exploit the nonuniversality among gaugino masses to realize large mass splitting between the colored and noncolored sfermions. Thus, the sleptons can have masses in the few hundred GeV range, whereas the colored sparticles turn out to be an order of magnitude or so heavier. In both models the resolution of the muon g-2 anomaly is compatible, among other things, with a 125126 GeV Higgs boson mass and the WMAP dark matter bounds.

  9. DOE - Office of Legacy Management -- Bendix Aviation Corp Pioneer Div - IA

    Office of Legacy Management (LM)

    05 Corp Pioneer Div - IA 05 FUSRAP Considered Sites Site: BENDIX AVIATION CORP., PIONEER DIV. (IA.05 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Pioneer Division, Bendix Aviation Corporation Bendix Aviation Corporation Bendix Pioneer Division IA.05-1 IA.05-2 IA.05-3 Location: Davenport , Iowa IA.05-1 Evaluation Year: 1990 IA.05-2 IA.05-4 Site Operations: Conducted studies to investigate the feasibility of using sonic cleaning equipment to

  10. Resonant ?<mo>+? stretchy='false'>?mo>?<mo>+?>0mn> amplitude from Quantum Chromodynamics

    SciTech Connect (OSTI)

    Briceo, Ral A.; Dudek, Jozef J.; Edwards, Robert G.; Shultz, Christian J.; Thomas, Christopher E.; Wilson, David J.

    2015-12-08

    We present the first ab initio calculation of a radiative transition of a hadronic resonance within Quantum Chromodynamics (QCD). We compute the amplitude for $\\pi\\pi \\to \\pi\\gamma^\\star$, as a function of the energy of the $\\pi\\pi$ pair and the virtuality of the photon, in the kinematic regime where $\\pi\\pi$ couples strongly to the unstable $\\rho$ resonance. This exploratory calculation is performed using a lattice discretization of QCD with quark masses corresponding to $m_\\pi \\approx 400$ MeV. As a result, we obtain a description of the energy dependence of the transition amplitude, constrained at 48 kinematic points, that we can analytically continue to the $\\rho$ pole and identify from its residue the $\\rho \\to \\pi\\gamma^\\star$ form-factor.

  11. Lattice dynamics of BaFe<mn>2mn>X>3mn><mo>(X=>S<mo>,>Se<mo>)> compounds

    SciTech Connect (OSTI)

    Popovi?, Z. V.; ?epanovi?, M.; Lazarevi?, N.; Opa?i?, M.; Radonji?, M. M.; Tanaskovi?, D.; Lei, Hechang; Petrovic, C.

    2015-02-27

    We present the Raman scattering spectra of the S=2 spin ladder compounds BaFe?X? (X=S,Se) in a temperature range between 20 and 400 K. Although the crystal structures of these two compounds are both orthorhombic and very similar, they are not isostructural. The unit cell of BaFe?S? (BaFe?Se?) is base-centered Cmcm (primitive Pnma), giving 18 (36) modes to be observed in the Raman scattering experiment. We have detected almost all Raman active modes, predicted by factor group analysis, which can be observed from the cleavage planes of these compounds. Assignment of the observed Raman modes of BaFe?S(Se)? is supported by the lattice dynamics calculations. The antiferromagnetic long-range spin ordering in BaFe?Se? below TN=255K leaves a fingerprint both in the A1g and B3g phonon mode linewidth and energy.

  12. Sweetspot: Near-infrared observations of 13 type Ia supernovae...

    Office of Scientific and Technical Information (OSTI)

    With only one to three points per light curve and a prior on the time of maximum from the ... These observations continue to demonstrate the improved standard brightness of SNe Ia in ...

  13. CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS...

    Office of Scientific and Technical Information (OSTI)

    whose SNe Ia provide the most precise luminosity calibrations: SN 1994ae in NGC 3370, SN ... including 57 with P>60 days, which extend these period-luminosity (P-L) relations. ...

  14. Turbulence-Flame Interactions in Type Ia Supernovae (Journal...

    Office of Scientific and Technical Information (OSTI)

    For an assumed background of isotropic Kolmogorov turbulence with an energy characteristic of SN Ia, we find a transition density between 1 and 3 x 107 g cm-3 where the nature of ...

  15. PRODUCTION OF THE p-PROCESS NUCLEI IN THE CARBON-DEFLAGRATION MODEL FOR TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Kusakabe, Motohiko; Iwamoto, Nobuyuki; Nomoto, Ken'ichi E-mail: iwamoto.nobuyuki@jaea.go.jp

    2011-01-01

    We calculate the nucleosynthesis of proton-rich isotopes in the carbon-deflagration model for Type Ia supernovae (SNe Ia). The seed abundances are obtained by calculating the s-process nucleosynthesis that is expected to occur in the repeating helium shell flashes on the carbon-oxygen (CO) white dwarf (WD) during mass accretion from a binary companion. When the deflagration wave passes through the outer layer of the CO WD, p-nuclei are produced by photodisintegration reactions on s-nuclei in a region where the peak temperature ranges from 1.9 to 3.6 x 10{sup 9} K. We confirm the sensitivity of the p-process on the initial distribution of s-nuclei. We show that the initial C/O ratio in the WD does not affect much the yield of p-nuclei. On the other hand, the abundance of {sup 22}Ne left after s-processing has a large influence on the p-process via the {sup 22}Ne({alpha},n) reaction. We find that about 50% of p-nuclides are co-produced when normalized to their solar abundances in all adopted cases of seed distribution. Mo and Ru, which are largely underproduced in Type II supernovae (SNe II), are produced more than in SNe II although they are underproduced with respect to the yield levels of other p-nuclides. The ratios between p-nuclei and iron in the ejecta are larger than the solar ratios by a factor of 1.2. We also compare the yields of oxygen, iron, and p-nuclides in SNe Ia and SNe II and suggest that SNe Ia could make a larger contribution than SNe II to the solar system content of p-nuclei.

  16. Improved Constraints on Type Ia Supernova Host Galaxy Properties using

    Office of Scientific and Technical Information (OSTI)

    Multi-Wavelength Photometry and their Correlations with Supernova Properties (Journal Article) | SciTech Connect Improved Constraints on Type Ia Supernova Host Galaxy Properties using Multi-Wavelength Photometry and their Correlations with Supernova Properties Citation Details In-Document Search Title: Improved Constraints on Type Ia Supernova Host Galaxy Properties using Multi-Wavelength Photometry and their Correlations with Supernova Properties We improve estimates of the stellar mass and

  17. CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS FOR THE

    Office of Scientific and Technical Information (OSTI)

    HUBBLE CONSTANT (Journal Article) | SciTech Connect CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS FOR THE HUBBLE CONSTANT Citation Details In-Document Search Title: CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS FOR THE HUBBLE CONSTANT This is the first of two papers reporting measurements from a program to determine the Hubble constant to {approx}5% precision from a refurbished distance ladder. We present new observations of 110 Cepheid variables in the

  18. Climate Action Champions: Dubuque, IA | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Dubuque, IA Climate Action Champions: Dubuque, IA The City of Dubuque, Iowa, features a rich history, a diverse arts and cultural scene, and abundant natural beauty, including majestic limestone bluffs along the Mississippi riverfront. Sustainability is among the city’s top priorities for the future. | Photo courtesy of the City of Dubuque. The City of Dubuque, Iowa, features a rich history, a diverse arts and cultural scene, and abundant natural beauty, including majestic limestone bluffs

  19. Multichannel <mn>0mn> stretchy='false'>?mo>>2mn> and <mn>1mn> stretchy='false'>?mo>>2mn> transition amplitudes for arbitrary spin particles in a finite volume

    SciTech Connect (OSTI)

    Hansen, Maxwell; Briceno, Raul

    2015-10-01

    We present a model-independent, non-perturbative relation between finite-volume matrix elements and infinite-volume $\\textbf{0}\\rightarrow\\textbf{2}$ and $\\textbf{1}\\rightarrow\\textbf{2}$ transition amplitudes. Our result accommodates theories in which the final two-particle state is coupled to any number of other two-body channels, with all angular momentum states included. The derivation uses generic, fully relativistic field theory, and is exact up to exponentially suppressed corrections in the lightest particle mass times the box size. This work distinguishes itself from previous studies by accommodating particles with any intrinsic spin. To illustrate the utility of our general result, we discuss how it can be implemented for studies of $N+\\mathcal{J}~\\rightarrow~(N\\pi,N\\eta,N\\eta',\\Sigma K,\\Lambda K)$ transitions, where $\\mathcal{J}$ is a generic external current. The reduction of rotational symmetry, due to the cubic finite volume, manifests in this example through the mixing of S- and P-waves when the system has nonzero total momentum.

  20. New approaches for modeling type Ia supernovae (Conference) | SciTech

    Office of Scientific and Technical Information (OSTI)

    Connect Conference: New approaches for modeling type Ia supernovae Citation Details In-Document Search Title: New approaches for modeling type Ia supernovae Type Ia supernovae (SNe Ia) are the largest thermonuclearexplosions in the Universe. Their light output can be seen across greatstances and has led to the discovery that the expansion rate of theUniverse is accelerating. Despite the significance of SNe Ia, there arestill a large number of uncertainties in current theoretical

  1. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese

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

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert; et al

    2015-03-12

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only bemore » achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.« less

  2. High Mn austenitic stainless steel

    DOE Patents [OSTI]

    Yamamoto, Yukinori (Oak Ridge, TN) [Oak Ridge, TN; Santella, Michael L (Knoxville, TN) [Knoxville, TN; Brady, Michael P (Oak Ridge, TN) [Oak Ridge, TN; Maziasz, Philip J (Oak Ridge, TN) [Oak Ridge, TN; Liu, Chain-tsuan (Knoxville, TN) [Knoxville, TN

    2010-07-13

    An austenitic stainless steel alloy includes, in weight percent: >4 to 15 Mn; 8 to 15 Ni; 14 to 16 Cr; 2.4 to 3 Al; 0.4 to 1 total of at least one of Nb and Ta; 0.05 to 0.2 C; 0.01 to 0.02 B; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1W; up to 3 Cu; up to 1 Si; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale including alumina, nanometer scale sized particles distributed throughout the microstructure, the particles including at least one of NbC and TaC, and a stable essentially single phase FCC austenitic matrix microstructure that is essentially delta-ferrite-free and essentially BCC-phase-free.

  3. Team OptiMN

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    University of Minnesota Team OptiMN "OptiMN Impact Home" Project Summary Designed to fit on the majority of North Minneapolis infill lots, the OptiMN Impact Home is a collaborative project between the University of Minnesota and Urban Homeworks. The overarching goal was a flexible, high-performance, energy-efficient, and affordable house that can be easily built by Urban Homeworks and purchased by eligible low-income residents of North Minneapolis through the Green Homes North program.

  4. CRAD, NNSA- Maintenance (MN)

    Broader source: Energy.gov [DOE]

    CRAD for Maintenance (MN). Criteria Review and Approach Documents (CRADs) that can be used to conduct a well-organized and thorough assessment of elements of safety and health programs.

  5. US WNC MO Site Consumption

    U.S. Energy Information Administration (EIA) Indexed Site

    WNC MO Site Consumption million Btu $0 $500 $1,000 $1,500 $2,000 $2,500 US WNC MO Expenditures dollars ALL ENERGY average per household (excl. transportation) 0 3,000 6,000 9,000 12,000 15,000 US WNC MO Site Consumption kilowatthours $0 $300 $600 $900 $1,200 $1,500 US WNC MO Expenditures dollars ELECTRICITY ONLY average per household * Missouri households consume an average of 100 million Btu per year, 12% more than the U.S. average. * Average household energy costs in Missouri are slightly less

  6. Turbulence-Flame Interactions in Type Ia Supernovae (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Journal Article: Turbulence-Flame Interactions in Type Ia Supernovae Citation Details In-Document Search Title: Turbulence-Flame Interactions in Type Ia Supernovae × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of

  7. Type Ia supernovae from merging white dwarfs. II. Post-merger...

    Office of Scientific and Technical Information (OSTI)

    Type Ia supernovae from merging white dwarfs. II. Post-merger detonations Citation Details In-Document Search Title: Type Ia supernovae from merging white dwarfs. II. Post-merger ...

  8. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397

    Office of Scientific and Technical Information (OSTI)

    from the enhanced abundances of nickel and manganese (Journal Article) | SciTech Connect A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese Citation Details In-Document Search Title: A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One

  9. SN 2006bt: A PERPLEXING, TROUBLESOME, AND POSSIBLY MISLEADING TYPE Ia

    Office of Scientific and Technical Information (OSTI)

    SUPERNOVA (Journal Article) | SciTech Connect SN 2006bt: A PERPLEXING, TROUBLESOME, AND POSSIBLY MISLEADING TYPE Ia SUPERNOVA Citation Details In-Document Search Title: SN 2006bt: A PERPLEXING, TROUBLESOME, AND POSSIBLY MISLEADING TYPE Ia SUPERNOVA SN 2006bt displays characteristics unlike those of any other known Type Ia supernova (SN Ia). We present optical light curves and spectra of SN 2006bt which demonstrate the peculiar nature of this object. SN 2006bt has broad, slowly declining

  10. Type Ia supernovae from merging white dwarfs. II. Post-merger detonations

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Type Ia supernovae from merging white dwarfs. II. Post-merger detonations Citation Details In-Document Search Title: Type Ia supernovae from merging white dwarfs. II. Post-merger detonations Merging carbon-oxygen (CO) white dwarfs are a promising progenitor system for Type Ia supernovae (SNe Ia), but the underlying physics and timing of the detonation are still debated. If an explosion occurs after the secondary star is fully disrupted, the exploding

  11. FIRST EVIDENCE OF GLOBULAR CLUSTER FORMATION FROM THE EJECTA OF PROMPT TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan); Bekki, Kenji, E-mail: taku.tsujimoto@nao.ac.jp [ICRAR, M468, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

    2012-06-01

    Recent spectroscopic observations of globular clusters (GCs) in the Large Magellanic Cloud (LMC) have discovered that one of the intermediate-age GCs, NGC 1718, with [Fe/H] = -0.7 has an extremely low [Mg/Fe] ratio of {approx}-0.9. We propose that NGC 1718 was formed from the ejecta of Type Ia supernovae mixed with very metal-poor ([Fe/H] <-1.3) gas about {approx}2 Gyr ago. The proposed scenario is shown to be consistent with the observed abundances of Fe-group elements such as Cr, Mn, and Ni. In addition, compelling evidence for asymptotic giant branch stars playing a role in chemical enrichment during this GC formation is found. We suggest that the origin of the metal-poor gas is closely associated with efficient gas transfer from the outer gas disk of the Small Magellanic Cloud to the LMC disk. We anticipate that the outer part of the LMC disk contains field stars exhibiting significantly low [Mg/Fe] ratios, formed through the same process as NGC 1718.

  12. A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA Citation Details In-Document Search Title: A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA One of the major differences between various explosion scenarios of Type Ia supernovae (SNe Ia) is the remaining amount of unburned (C+O) material and its velocity distribution within the expanding ejecta. While oxygen absorption features are not uncommon in the spectra of SNe Ia before maximum light, the presence of strong

  13. An Analysis of Department of Defense Instruction 8500.2 'Information Assurance (IA) Implementation.'

    SciTech Connect (OSTI)

    Campbell, Philip LaRoche

    2012-01-01

    The Department of Defense (DoD) provides its standard for information assurance in its Instruction 8500.2, dated February 6, 2003. This Instruction lists 157 'IA Controls' for nine 'baseline IA levels.' Aside from distinguishing IA Controls that call for elevated levels of 'robustness' and grouping the IA Controls into eight 'subject areas' 8500.2 does not examine the nature of this set of controls, determining, for example, which controls do not vary in robustness, how this set of controls compares with other such sets, or even which controls are required for all nine baseline IA levels. This report analyzes (1) the IA Controls, (2) the subject areas, and (3) the Baseline IA levels. For example, this report notes that there are only 109 core IA Controls (which this report refers to as 'ICGs'), that 43 of these core IA Controls apply without variation to all nine baseline IA levels and that an additional 31 apply with variations. This report maps the IA Controls of 8500.2 to the controls in NIST 800-53 and ITGI's CoBIT. The result of this analysis and mapping, as shown in this report, serves as a companion to 8500.2. (An electronic spreadsheet accompanies this report.)

  14. US WNC MO Site Consumption

    Gasoline and Diesel Fuel Update (EIA)

    in the South than those in the Midwest. 0% 20% 40% 60% 80% 100% US WNC MO OtherNone Propane Electricity Natural Gas MAIN HEATING FUEL USED COOLING EQUIPMENT USED DIVISION:...

  15. Type Ia Supernova Spectral Line Ratios as LuminosityIndicators

    SciTech Connect (OSTI)

    Bongard, Sebastien; Baron, E.; Smadja, G.; Branch, David; Hauschildt, Peter H.

    2005-12-07

    Type Ia supernovae have played a crucial role in thediscovery of the dark energy, via the measurement of their light curvesand the determination of the peak brightness via fitting templates to theobserved lightcurve shape. Two spectroscopic indicators are also known tobe well correlated with peak luminosity. Since the spectroscopicluminosity indicators are obtained directly from observed spectra, theywill have different systematic errors than do measurements usingphotometry. Additionally, these spectroscopic indicators may be usefulfor studies of effects of evolution or age of the SNe~;Ia progenitorpopulation. We present several new variants of such spectroscopicindicators which are easy to automate and which minimize the effects ofnoise. We show that these spectroscopic indicators can be measured byproposed JDEM missions such as snap and JEDI.

  16. Power-law cosmology, SN Ia, and BAO

    SciTech Connect (OSTI)

    Dolgov, Aleksander; Halenka, Vitali; Tkachev, Igor E-mail: vithal@umich.edu

    2014-10-01

    We revise observational constraints on the class of models of modified gravity which at low redshifts lead to a power-law cosmology. To this end we use available public data on Supernova Ia and on baryon acoustic oscillations. We show that the expansion regime a(t)?t{sup ?} with ? close to 3/2 in a spatially flat universe is a good fit to these data.

  17. IA-HySafe International Conference on Hydrogen Safety (ICHS)

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

    IA-HySafe International Conference on Hydrogen Safety (ICHS) - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle

  18. Microsoft PowerPoint - IEEE IAS PES 102313.pptx

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

    DOE's ARRA Smart Grid Program Steve Bossart, Senior Energy Analyst IEEE IAS/PES Pittsburgh Section October 23, 2013 # Topics * OE ARRA Smart Grid Program * OE ARRA Smart Grid Progress * Results and Case Studies * Life After ARRA Smart Grid # DOE OE ARRA Smart Grid Program # American Recovery and Reinvestment Act ($4.5B) * Smart Grid Investment Grants (99 projects) - $3.4 billion Federal; $4.7 billion private sector - > 800 PMUs covering almost 100% of transmission - ~ 8000 distribution

  19. Signatures of a companion star in type Ia supernovae

    SciTech Connect (OSTI)

    Maeda, Keiichi [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Kutsuna, Masamichi; Shigeyama, Toshikazu, E-mail: keiichi.maeda@kusastro.kyoto-u.ac.jp [Research Center for the Early Universe, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2014-10-10

    Although type Ia supernovae (SNe Ia) have been used as precise cosmological distance indicators, their progenitor systems remain unresolved. One of the key questions is whether there is a nondegenerate companion star at the time of a thermonuclear explosion of a white dwarf. In this paper, we investigate whether an interaction between the SN ejecta and the companion star may result in observable footprints around the maximum brightness and thereafter, by performing multidimensional radiation transfer simulations based on hydrodynamic simulations of the interaction. We find that such systems result in variations in various observational characteristics due to different viewing directions, and the predicted behaviors (redder and fainter for the companion direction) are the opposite of what were suggested by the previous study. The variations are generally modest and within observed scatters. However, the model predicts trends between some observables different from those observationally derived, so a large sample of SNe Ia with small calibration errors may be used to constrain the existence of such a companion star. The variations in different colors in optical band passes can be mimicked by external extinctions, so such an effect could be a source of scatter in the peak luminosity and derived distance. After the peak, hydrogen-rich materials expelled from the companion will manifest themselves in hydrogen lines, but H? is extremely difficult to identify. Alternatively, we find that P{sub ?} in postmaximum near-infrared spectra can potentially provide a powerful diagnostic.

  20. MN Office of Energy Security | Open Energy Information

    Open Energy Info (EERE)

    MN Office of Energy Security Jump to: navigation, search Name: MN Office of Energy Security Place: St. Paul, MN Website: www.mnofficeofenergysecurity.c References: MN Office of...

  1. DOE - Office of Legacy Management -- St Louis Airport - MO 01

    Office of Legacy Management (LM)

    Airport - MO 01 FUSRAP Considered Sites St. Louis Airport, MO Alternate Name(s): Airport Site St. Louis Airport Storage Site (SLAPS) Former Robertson Storage Area Robertson Airport MO.01-1 MO.01-2 Location: Brown Road, Robertson, Missouri MO.01-2 Historical Operations: Stored uranium process residues containing uranium, radium, and thorium for the MED and AEC. MO.01-2 MO.01-3 MO.01-4 Eligibility Determination: Eligible MO.01-1 MO.01-7 Radiological Survey(s): Assessment Surveys MO.01-4 MO.01-5

  2. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Journal Article: Type Ia Supernova Hubble Residuals and Host-Galaxy Properties Citation Details In-Document Search Title: Type Ia Supernova Hubble Residuals and Host-Galaxy Properties Kim et al. (2013) [K13] introduced a new methodology for determining peak- brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized

  3. Color dispersion and Milky-Way-like reddening among type Ia supernovae

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Color dispersion and Milky-Way-like reddening among type Ia supernovae Citation Details In-Document Search Title: Color dispersion and Milky-Way-like reddening among type Ia supernovae Past analyses of Type Ia supernovae have identified an irreducible scatter of 5%-10% in distance, widely attributed to an intrinsic dispersion in luminosity. Another equally valid source of this scatter is intrinsic dispersion in color. Misidentification of the true source

  4. A SEARCH FOR NEW CANDIDATE SUPER-CHANDRASEKHAR-MASS TYPE Ia SUPERNOVAE IN

    Office of Scientific and Technical Information (OSTI)

    THE NEARBY SUPERNOVA FACTORY DATA SET (Journal Article) | SciTech Connect A SEARCH FOR NEW CANDIDATE SUPER-CHANDRASEKHAR-MASS TYPE Ia SUPERNOVAE IN THE NEARBY SUPERNOVA FACTORY DATA SET Citation Details In-Document Search Title: A SEARCH FOR NEW CANDIDATE SUPER-CHANDRASEKHAR-MASS TYPE Ia SUPERNOVAE IN THE NEARBY SUPERNOVA FACTORY DATA SET We present optical photometry and spectroscopy of five Type Ia supernovae discovered by the Nearby Supernova Factory selected to be spectroscopic analogs

  5. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Journal Article: Type Ia Supernova Hubble Residuals and Host-Galaxy Properties Citation Details In-Document Search Title: Type Ia Supernova Hubble Residuals and Host-Galaxy Properties Kim et al. (2013) [K13] introduced a new methodology for determining peak- brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized

  6. Type Ia supernovae yielding distances with 3-4% precision (Journal Article)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Type Ia supernovae yielding distances with 3-4% precision Citation Details In-Document Search Title: Type Ia supernovae yielding distances with 3-4% precision The luminosities of Type Ia supernovae (SN), the thermonuclear explosions of white dwarf stars, vary systematically with their intrinsic color and light-curve decline rate. These relationships have been used to calibrate their luminosities to within ~0.14-0.20 mag from broadband optical light curves, yielding

  7. VARIABLE SODIUM ABSORPTION IN A LOW-EXTINCTION TYPE Ia SUPERNOVA (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect VARIABLE SODIUM ABSORPTION IN A LOW-EXTINCTION TYPE Ia SUPERNOVA Citation Details In-Document Search Title: VARIABLE SODIUM ABSORPTION IN A LOW-EXTINCTION TYPE Ia SUPERNOVA Recent observations have revealed that some Type Ia supernovae exhibit narrow, time-variable Na I D absorption features. The origin of the absorbing material is controversial, but it may suggest the presence of circumstellar gas in the progenitor system prior to the explosion, with significant

  8. Member Case Studies: LED Street Lighting Programs in Algona (IA), Asheville

    Energy Savers [EERE]

    (NC), and Boston (MA) | Department of Energy Member Case Studies: LED Street Lighting Programs in Algona (IA), Asheville (NC), and Boston (MA) Member Case Studies: LED Street Lighting Programs in Algona (IA), Asheville (NC), and Boston (MA) This May 8, 2013 webcast featured presentations from DOE Municipal Solid-State Street Lighting Consortium member cities about their experiences with LED street lighting. Presenters John Bilsten of Algona (IA) Municipal Utilities, Maggie Ullman of the City

  9. The Carnegie Supernova Project: Intrinsic colors of type Ia supernovae

    SciTech Connect (OSTI)

    Burns, Christopher R.; Persson, S. E.; Freedman, Wendy L.; Madore, Barry F. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Stritzinger, Maximilian; Contreras, Carlos [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Phillips, M. M.; Hsiao, E. Y.; Boldt, Luis; Campillay, Abdo; Castelln, Sergio; Morrell, Nidia; Salgado, Francisco [Carnegie Institution of Washington, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Folatelli, Gaston [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 277-8583 Kashiwa (Japan); Suntzeff, Nicholas B. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, Department of Physics and Astronomy, College Station, TX 77843 (United States)

    2014-07-01

    We present an updated analysis of the intrinsic colors of Type Ia supernova (SNe Ia) using the latest data release of the Carnegie Supernova Project. We introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find that these peculiar types can be seen as extensions to the population of 'normal' SNe Ia. With a larger number of objects, an updated fit to the Lira relation is presented along with evidence for a dependence on the late-time slope of the B V light-curves with stretch and color. Using the full wavelength range from u to H band, we place constraints on the reddening law for the sample as a whole and also for individual events/hosts based solely on the observed colors. The photometric data continue to favor low values of R{sub V} , though with large variations from event to event, indicating an intrinsic distribution. We confirm the findings of other groups that there appears to be a correlation between the derived reddening law, R{sub V} , and the color excess, E(B V), such that larger E(B V) tends to favor lower R{sub V} . The intrinsic u-band colors show a relatively large scatter that cannot be explained by variations in R{sub V} or by the Goobar power-law for circumstellar dust, but rather is correlated with spectroscopic features of the supernova and is therefore likely due to metallicity effects.

  10. HUBBLE RESIDUALS OF NEARBY TYPE Ia SUPERNOVAE ARE CORRELATED WITH HOST

    Office of Scientific and Technical Information (OSTI)

    GALAXY MASSES (Journal Article) | SciTech Connect HUBBLE RESIDUALS OF NEARBY TYPE Ia SUPERNOVAE ARE CORRELATED WITH HOST GALAXY MASSES Citation Details In-Document Search Title: HUBBLE RESIDUALS OF NEARBY TYPE Ia SUPERNOVAE ARE CORRELATED WITH HOST GALAXY MASSES From Sloan Digital Sky Survey u'g'r'i'z' imaging, we estimate the stellar masses of the host galaxies of 70 low-redshift Type Ia supernovae (SNe Ia, 0.015 <z< 0.08) from the hosts' absolute luminosities and mass-to-light

  11. IMPROVED DARK ENERGY CONSTRAINTS FROM {approx}100 NEW CfA SUPERNOVA TYPE Ia

    Office of Scientific and Technical Information (OSTI)

    LIGHT CURVES (Journal Article) | SciTech Connect IMPROVED DARK ENERGY CONSTRAINTS FROM {approx}100 NEW CfA SUPERNOVA TYPE Ia LIGHT CURVES Citation Details In-Document Search Title: IMPROVED DARK ENERGY CONSTRAINTS FROM {approx}100 NEW CfA SUPERNOVA TYPE Ia LIGHT CURVES We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski

  12. Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light

    Office of Scientific and Technical Information (OSTI)

    Curves (Journal Article) | SciTech Connect Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves Citation Details In-Document Search Title: Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski et al. to form the

  13. Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes:

    Office of Scientific and Technical Information (OSTI)

    MLCS2k2 (Journal Article) | SciTech Connect Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes: MLCS2k2 Citation Details In-Document Search Title: Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes: MLCS2k2 We present an updated version of the Multicolor Light Curve Shape method to measure distances to type Ia supernovae (SN Ia), incorporating new procedures for K-correction and extinction corrections. We also develop a simple model to

  14. THE HYBRID CONe WD + He STAR SCENARIO FOR THE PROGENITORS OF TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Wang, B.; Meng, X.; Liu, D.-D.; Han, Z.; Liu, Z.-W.

    2014-10-20

    Hybrid CONe white dwarfs (WDs) have been suggested to be possible progenitors of type Ia supernovae (SNe Ia). In this Letter, we systematically studied the hybrid CONe WD + He star scenario for the progenitors of SNe Ia, in which a hybrid CONe WD increases its mass to the Chandrasekhar mass limit by accreting He-rich material from a non-degenerate He star. We obtained the SN Ia birthrates and delay times for this scenario using to a series of detailed binary population synthesis simulations. The SN Ia birthrates for this scenario are ?0.033-0.539 10{sup 3} yr{sup 1}, which roughly accounts for 1%-18% of all SNe Ia. The estimated delay times are ?28Myr-178Myr, which makes these the youngest SNe Ia predicted by any progenitor model so far. We suggest that SNe Ia from this scenario may provide an alternative explanation for type Iax SNe. We also presented some properties of the donors at the point when the WDs reach the Chandrasekhar mass. These properties may be a good starting point for investigating the surviving companions of SNe Ia and for constraining the progenitor scenario studied in this work.

  15. CfA3: 185 TYPE Ia SUPERNOVA LIGHT CURVES FROM THE CfA (Journal...

    Office of Scientific and Technical Information (OSTI)

    Ia in their color and light-curve-shapeluminosity relation that they should be treated ... COLOR; COSMOLOGY; DUSTS; GALAXIES; LUMINOSITY; PHOTOMETRY; SUPERNOVAE Word Cloud More ...

  16. Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light

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

    Curves (Journal Article) | SciTech Connect Journal Article: Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves Citation Details In-Document Search Title: Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski

  17. Sweetspot: Near-infrared observations of 13 type Ia supernovae from a new

    Office of Scientific and Technical Information (OSTI)

    NOAO survey probing the nearby smooth Hubble flow (Journal Article) | SciTech Connect Sweetspot: Near-infrared observations of 13 type Ia supernovae from a new NOAO survey probing the nearby smooth Hubble flow Citation Details In-Document Search Title: Sweetspot: Near-infrared observations of 13 type Ia supernovae from a new NOAO survey probing the nearby smooth Hubble flow We present 13 Type Ia supernovae (SNe Ia) observed in the rest-frame near-infrared (NIR) from 0.02 < z < 0.09

  18. THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET Citation Details In-Document Search Title: THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET We examine the absolute magnitudes and light-curve shapes of 14 nearby (redshift z = 0.004-0.027) Type Ia supernovae (SNe Ia) observed in the ultraviolet (UV) with the Swift Ultraviolet/Optical Telescope. Colors and absolute magnitudes are calculated using both a standard Milky Way extinction

  19. Category:Minneapolis, MN | Open Energy Information

    Open Energy Info (EERE)

    16 total. SVFullServiceRestaurant Minneapolis MN Northern States Power Co (Minnesota) Excel Energy.png SVFullServiceRestauran... 89 KB SVHospital Minneapolis MN Northern States...

  20. SSL Demonstration: Street Lighting, Kansas City, MO

    SciTech Connect (OSTI)

    2013-08-01

    GATEWAY program report brief summarizing an SSL street lighting demonstration at nine separate installations in Kansas City, MO.

  1. Grouping normal type Ia supernovae by UV to optical color differences

    SciTech Connect (OSTI)

    Milne, Peter A.; Brown, Peter J.; Roming, Peter W. A.; Bufano, Filomena; Gehrels, Neil

    2013-12-10

    Observations of many Type Ia supernovae (SNe Ia) for multiple epochs per object with the Swift Ultraviolet Optical Telescope instrument have revealed that there exists order to the differences in the UV-optical colors of optically normal supernovae (SNe). We examine UV-optical color curves for 23 SNe Ia, dividing the SNe into four groups, and find that roughly one-third of 'NUV-blue' SNe Ia have bluer UV-optical colors than the larger 'NUV-red' group. Two minor groups are recognized, 'MUV-blue' and 'irregular' SNe Ia. While we conclude that the latter group is a subset of the NUV-red group, containing the SNe with the broadest optical peaks, we conclude that the 'MUV-blue' group is a distinct group. Separating into the groups and accounting for the time evolution of the UV-optical colors lowers the scatter in two NUV-optical colors (e.g., u v and uvw1 v) to the level of the scatter in b v. This finding is promising for extending the cosmological utilization of SNe Ia into the NUV. We generate spectrophotometry of 33 SNe Ia and determine the correct grouping for each. We argue that there is a fundamental spectral difference in the 2900-3500 wavelength range, a region suggested to be dominated by absorption from iron-peak elements. The NUV-blue SNe Ia feature less absorption than the NUV-red SNe Ia. We show that all NUV-blue SNe Ia in this sample also show evidence of unburned carbon in optical spectra, whereas only one NUV-red SN Ia features that absorption line. Every NUV-blue event also exhibits a low gradient of the Si II ?6355 absorption feature. Many NUV-red events also exhibit a low gradient, perhaps suggestive that NUV-blue events are a subset of the larger low-velocity gradient group.

  2. Two-leg SU<mo>(>2mn>n)> spin ladder: A low-energy effective field theory approach

    SciTech Connect (OSTI)

    Lecheminant, P.; Tsvelik, A. M.

    2015-05-07

    We present a field-theory analysis of a model of two SU(2n)-invariant magnetic chains coupled by a generic interaction preserving time reversal and inversion symmetry. Contrary to the SU(2)-invariant case the zero-temperature phase diagram of such two-leg spin ladder does not contain topological phases. Thus, only generalized Valence Bond Solid phases are stabilized when n > 1 with different wave vectors and ground-state degeneracies. In particular, we find a phase which is made of a cluster of 2n spins put in an SU(2n) singlet state. For n = 3, this cluster phase is relevant to ?Yb ultracold atoms, with an emergent SU(6) symmetry, loaded in a double-well optical lattice.

  3. Electronic structure of the heavy-fermion caged compound Ce<mn>3mn>Pd>20mn>X>6mn><mo>(mo>X=>Si,Ge<mo>)> studied by density functional theory and photoelectron spectroscopy

    SciTech Connect (OSTI)

    Yamaoka, Hitoshi; Schwier, Eike F.; Arita, Masashi; Shimada, Kenya; Tsujii, Naohito; Jarrige, Ignace; Jiang, Jian; Hayashi, Hirokazu; Iwasawa, Hideaki; Namatame, Hirofumi; Taniguchi, Masaki; Kitazawa, Hideaki

    2015-03-30

    The electronic structure of Ce₃Pd₂₀X₆ (X = Si, Ge) has been studied using detailed density functional theory (DFT) calculations and high-resolution photoelectron spectroscopy (PES) measurements. The orbital decomposition of the electronic structure by DFT calculations indicates that Ce atoms at the (8c) site surrounded by 16 Pd atoms have a more localized nature and a tendency to be magnetic. Ce atoms in the (4a) site surrounded by 12 Pd and 6 X atoms, on the other, show only a negligible magnetic moment. In the photoemission valence-band spectra we observe a strong f⁰ (Ce⁴⁺) component with a small fraction of f¹ (Ce³⁺) component. The spectral weight of f¹ component near the Fermi level Ce₃Pd₂₀Si₆ is stronger than that for Ce₃Pd₂₀Ge₆ at the 4d-4f resonance, suggesting stronger c-f hybridization in the former. This may hint to the origin of the large electronic specific coefficient of Ce₃Pd₂₀Si₆ compared to Ce₃Pd₂₀Ge₆.

  4. THE BIRTH RATE OF SNe Ia FROM HYBRID CONe WHITE DWARFS

    SciTech Connect (OSTI)

    Meng, Xiangcun [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Podsiadlowski, Philipp, E-mail: xiangcunmeng@ynao.ac.cn [Department of Astronomy, Oxford University, Oxford OX1 3RH (United Kingdom)

    2014-07-10

    Considering the uncertainties of the C-burning rate (CBR) and the treatment of convective boundaries, Chen et al. found that there is a regime where it is possible to form hybrid CONe white dwarfs (WDs), i.e., ONe WDs with carbon-rich cores. As these hybrid WDs can be as massive as 1.30 M {sub ?}, not much mass needs to be accreted for these objects to reach the Chandrasekhar limit and to explode as Type Ia supernovae (SNe Ia). We have investigated their contribution to the overall SN Ia birth rate and found that such SNe Ia tend to be relatively young with typical time delays between 0.1 and 1 Gyr, where some may be as young as 30 Myr. SNe Ia from hybrid CONe WDs may contribute several percent to all SNe Ia, depending on the common-envelope ejection efficiency and the CBR. We suggest that these SNe Ia may produce part of the 2002cx-like SN Ia class.

  5. New lifetime measurements in Pd<mn>109mn> and the onset of deformation at N<mo>=>60mn>

    SciTech Connect (OSTI)

    Bucher, B.; Mach, H.; Aprahamian, A.; Simpson, G. S.; Rissanen, J.; Ghiţă, D. G.; Olaizola, B.; Kurcewicz, W.; Äystö, J.; Bentley, I.; Eronen, T.; Fraile, L. M.; Jokinen, A.; Karvonen, P.; Moore, I. D.; Penttilä, H.; Reponen, M.; Ruchowska, E.; Saastamoinen, A.; Smith, M. K.; Weber, C.

    2015-12-14

    We measured several new subnanosecond lifetimes in 109Pd using the fast-timing βγ γ (t ) method. Fission fragments of the A = 109 mass chain were produced by bombarding natural uranium with 30 MeV protons at the Jyväskylä Ion Guide Isotope Separator On-Line (IGISOL) facility. We obtained lifetimes for excited states in 109Pd populated following β decay of 109Rh. The new lifetimes provide some insight into the evolution of nuclear structure in this mass region. In particular, the distinct structure of the two low-lying 7/2+ states occurring systematically across the Pd isotopic chain is supported by the new lifetime measurements. Finally, the available nuclear data indicate a sudden increase in deformation at N = 60 which is related to the strong p-n interaction between πg9/2 and νg7/2 valence nucleons expected in this region.

  6. Preferential Eu Site Occupation and Its Consequences in the Ternary Luminescent HalidesAB<mn>2mn>I<mn>5mn><mo>:Eu>2mn>+>(A<mo>=mo>Li<mo>–>Cs;B<mo>=>Sr, Ba)

    SciTech Connect (OSTI)

    Fang, C.  M.; Biswas, Koushik

    2015-07-22

    Several rare-earth-doped, heavy-metal halides have recently been identified as potential next-generation luminescent materials with high efficiency at low cost. AB2I5:Eu2+ (A=Li–Cs; B=Sr, Ba) is one such family of halides. Its members, such as CsBa2I5:Eu2+ and KSr2I5:Eu2+, are currently being investigated as high-performance scintillators with improved sensitivity, light yield, and energy resolution less than 3% at 662 keV. Within the AB2I5 family, our first-principles-based calculations reveal two remarkably different trends in Eu site occupation. The substitutional Eu ions occupy both eightfold-coordinated B1(VIII) and the sevenfold-coordinated B2(VII) sites in the Sr-containing compounds. However, in the Ba-containing crystals, Eu ions strongly prefer the B2(VII)sites. This random versus preferential distribution of Eu affects their electronic properties. The calculations also suggest that in the Ba-containing compounds one can expect the formation of Eu-rich domains. These results provide atomistic insight into recent experimental observations about the concentration and temperature effects in Eu-doped CsBa2I5. We discuss the implications of our results with respect to luminescent properties and applications. We also hypothesize Sr, Ba-mixed quaternary iodides ABaVIIISrVIII5:Eu as scintillators having enhanced homogeneity and electronic properties.

  7. On silicon group elements ejected by supernovae type IA

    SciTech Connect (OSTI)

    De, Soma; Timmes, F. X. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States); Brown, Edward F. [Joint Institute for Nuclear Astrophysics, University of Notre Dame, IN 46556 (United States); Calder, Alan C. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY (United States); Townsley, Dean M. [Department of Physics and Astronomy, The University of Alabama, Tuscaloosa, AL (United States); Athanassiadou, Themis [Swiss National Supercomputing Centre, Via Trevano 131, 6900 Lugano (Switzerland); Chamulak, David A. [Physics Division, Argonne National Laboratory, Argonne, IL (United States); Hawley, Wendy [Laboratoire d'Astrophysique de Marseille, Marseille cedex 13 F-13388 (France); Jack, Dennis, E-mail: somad@asu.edu [Departamento de Astronoma, Universidad de Guanajuato, Apartado Postal 144, 36000 Guanajuato (Mexico)

    2014-06-01

    There is evidence that the peak brightness of a Type Ia supernova is affected by the electron fraction Y {sub e} at the time of the explosion. The electron fraction is set by the aboriginal composition of the white dwarf and the reactions that occur during the pre-explosive convective burning. To date, determining the makeup of the white dwarf progenitor has relied on indirect proxies, such as the average metallicity of the host stellar population. In this paper, we present analytical calculations supporting the idea that the electron fraction of the progenitor systematically influences the nucleosynthesis of silicon group ejecta in Type Ia supernovae. In particular, we suggest the abundances generated in quasi-nuclear statistical equilibrium are preserved during the subsequent freeze-out. This allows potential recovery of Y {sub e} at explosion from the abundances recovered from an observed spectra. We show that measurement of {sup 28}Si, {sup 32}S, {sup 40}Ca, and {sup 54}Fe abundances can be used to construct Y {sub e} in the silicon-rich regions of the supernovae. If these four abundances are determined exactly, they are sufficient to recover Y {sub e} to 6%. This is because these isotopes dominate the composition of silicon-rich material and iron-rich material in quasi-nuclear statistical equilibrium. Analytical analysis shows the {sup 28}Si abundance is insensitive to Y {sub e}, the {sup 32}S abundance has a nearly linear trend with Y {sub e}, and the {sup 40}Ca abundance has a nearly quadratic trend with Y {sub e}. We verify these trends with post-processing of one-dimensional models and show that these trends are reflected in the model's synthetic spectra.

  8. DOE - Office of Legacy Management -- Washington University - MO 07

    Office of Legacy Management (LM)

    Washington University - MO 07 FUSRAP Considered Sites Site: WASHINGTON UNIVERSITY (MO.07 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: St. Louis , Missouri MO.07-1 Evaluation Year: 1987 MO.07-1 Site Operations: Activities were limited to programs involving relatively small quantities of radionuclides and chemicals in a controlled environment. MO.07-3 MO.07-1 Site Disposition: Eliminated - Potential for contamination remote MO.07-1

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

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses Citation Details In-Document Search Title: Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses 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

  10. ASYMMETRY IN THE OBSERVED METAL-RICH EJECTA OF THE GALACTIC TYPE IA

    Office of Scientific and Technical Information (OSTI)

    SUPERNOVA REMNANT G299.2-2.9 (Journal Article) | SciTech Connect ASYMMETRY IN THE OBSERVED METAL-RICH EJECTA OF THE GALACTIC TYPE IA SUPERNOVA REMNANT G299.2-2.9 Citation Details In-Document Search Title: ASYMMETRY IN THE OBSERVED METAL-RICH EJECTA OF THE GALACTIC TYPE IA SUPERNOVA REMNANT G299.2-2.9 We have performed a deep Chandra observation of the Galactic Type Ia supernova remnant G299.2-2.9. Here we report the initial results from our imaging and spectral analysis. The observed

  11. DOE - Office of Legacy Management -- Latty Avenue Site - MO 04

    Office of Legacy Management (LM)

    Latty Avenue Site - MO 04 FUSRAP Considered Sites Latty Avenue Site, MO Alternate Name(s): Futura Coatings Futura Chemical Company Facility Hazelwood Interim Storage Site (HISS) Former Cotter Site, Latty Avenue Properties Contemporary Metals Corp. Continental Mining and Milling MO.04-1 MO.04-2 MO.04-5 MO.04-6 MO.06-8 MO.06-11 Location: 9200 Latty Avenue, Hazelwood, Missouri MO.04-1 Historical Operations: Received, stored, and processed uranium residues for the AEC. Storage and processing were

  12. Study of e<mo>+>e<mo>- stretchy='false'>?mo>pp<mo accent='true' stretchy='false'>mo>?>0mn> in the vicinity of the ?<mo stretchy='false'>(mo>>3770mn> stretchy='false'>)mo>

    SciTech Connect (OSTI)

    Ablikim, M.; Achasov, M. ?N.; Ai, X.? C.; Albayrak, O.; Albrecht, M.; Ambrose, D. ?J.; An, F. ?F.; An, Q.; Bai, J. ?Z.; Baldini Ferroli, R.; Ban, Y.; Bennett, J.? V.; Bertani, M.; Bian, J.? M.; Boger, E.; Bondarenko, O.; Boyko, I.; Braun, S.; Briere, R.? A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G.? F.; Cetin, S.? A.; Chang, J.? F.; Chelkov, G.; Chen, G.; Chen, H.? S.; Chen, J.? C.; Chen, M.? L.; Chen, S.? J.; Chen, X.; Chen, X.? R.; Chen, Y.? B.; Cheng, H.? P.; Chu, X.? K.; Chu, Y.? P.; Cronin-Hennessy, D.; Dai, H.? L.; Dai, J.? P.; Dedovich, D.; Deng, Z.? Y.; Denig, A.; Denysenko, I.; Destefanis, M.; Ding, W.? M.; Ding, Y.; Dong, C.; Dong, J.; Dong, L.? Y.; Dong, M. ?Y.; Du, S.? X.; Fan, J.? Z.; Fang, J.; Fang, S. ?S.; Fang, Y.; Fava, L.; Feng, C. ?Q.; Fu, C. ?D.; Fuks, O.; Gao, Q.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W.? X.; Gradl, W.; Greco, M.; Gu, M. ?H.; Gu, Y.? T.; Guan, Y.? H.; Guo, A.? Q.; Guo, L.? B.; Guo, T.; Guo, Y.? P.; Han, Y.? L.; Harris, F.? A.; He, K.? L.; He, M.; He, Z.? Y.; Held, T.; Heng, Y.? K.; Hou, Z.? L.; Hu, C.; Hu, H.? M.; Hu, J. ?F.; Hu, T.; Huang, G.? M.; Huang, G. ?S.; Huang, H.? P.; Huang, J.? S.; Huang, L.; Huang, X. ?T.; Huang, Y.; Hussain, T.; Ji, C. ?S.; Ji, Q.; Ji, Q.? P.; Ji, X. ?B.; Ji, X.? L.; Jiang, L. ?L.; Jiang, L.? W.; Jiang, X.? S.; Jiao, J.? B.; Jiao, Z.; Jin, D.? P.; Jin, S.; Johansson, T.; Kalantar-Nayestanaki, N.; Kang, X. ?L.; Kang, X.? S.; Kavatsyuk, M.; Kloss, B.; Kopf, B.; Kornicer, M.; Khn, W.; Kupsc, A.; Lai, W.; Lange, J.? S.; Lara, M.; Larin, P.; Leyhe, M.; Li, C.? H.; Li, Cheng; Li, Cui; Li, D.; Li, D.? M.; Li, F.; Li, G.; Li, H.? B.; Li, J.? C.; Li, K.; Li, K.; Li, Lei; Li, P. ?R.; Li, Q.? J.; Li, T.; Li, W.? D.; Li, W.? G.; Li, X.? L.; Li, X.? N.; Li, X.? Q.; Li, Z.? B.; Liang, H.; Liang, Y.? F.; Liang, Y.? T.; Lin, D.? X.; Liu, B.? J.; Liu, C. ?L.; Liu, C.? X.; Liu, F.? H.; Liu, Fang; Liu, Feng; Liu, H. ?B.; Liu, H.? H.; Liu, H.? M.; Liu, J.; Liu, J.? P.; Liu, K.; Liu, K.? Y.; Liu, P.? L.; Liu, Q.; Liu, S.? B.; Liu, X.; Liu, Y.? B.; Liu, Z.? A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lou, X.? C.; Lu, G.? R.; Lu, H.? J.; Lu, H.? L.; Lu, J.? G.; Lu, X.? R.; Lu, Y.; Lu, Y.? P.; Luo, C.? L.; Luo, M.? X.; Luo, T.; Luo, X.? L.; Lv, M.; Ma, F.? C.; Ma, H. ?L.; Ma, Q.? M.; Ma, S.; Ma, T.; Ma, X. ?Y.; Maas, F. ?E.; Maggiora, M.; Malik, Q.? A.; Mao, Y.? J.; Mao, Z.? P.; Messchendorp, J.? G.; Min, J.; Min, T.? J.; Mitchell, R.? E.; Mo, X.? H.; Mo, Y.? J.; Moeini, H.; Morales Morales, C.; Moriya, K.; Muchnoi, N.? Yu.; Muramatsu, H.; Nefedov, Y.; Nikolaev, I. ?B.; Ning, Z.; Nisar, S.; Niu, X.? Y.; Olsen, S.? L.; Ouyang, Q.; Pacetti, S.; Pelizaeus, M.; Peng, H.? P.; Peters, K.; Ping, J.? L.; Ping, R.? G.; Poling, R.; Q., N.; Qi, M.; Qian, S.; Qiao, C.? F.; Qin, L.? Q.; Qin, X.? S.; Qin, Y.; Qin, Z. ?H.; Qiu, J. ?F.; Rashid, K.? H.; Redmer, C.? F.; Ripka, M.; Rong, G.; Ruan, X.? D.; Sarantsev, A.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C.? P.; Shen, X.? Y.; Sheng, H.? Y.; Shepherd, M.? R.; Song, W.? M.; Song, X. ?Y.; Spataro, S.; Spruck, B.; Sun, G.? X.; Sun, J. ?F.; Sun, S.? S.; Sun, Y.? J.; Sun, Y. ?Z.; Sun, Z. ?J.; Sun, Z.? T.; Tang, C.? J.; Tang, X.; Tapan, I.; Thorndike, E.? H.; Toth, D.; Ullrich, M.; Uman, I.; Varner, G.? S.; Wang, B.; Wang, D.; Wang, D.? Y.; Wang, K.; Wang, L.? L.; Wang, L. ?S.; Wang, M.; Wang, P.; Wang, P.? L.; Wang, Q.? J.; Wang, S.? G.; Wang, W.; Wang, X.? F.; Wang, Y.? D.; Wang, Y.? F.; Wang, Y.? Q.; Wang, Z.; Wang, Z. ?G.; Wang, Z.? H.; Wang, Z.? Y.; Wei, D.? H.; Wei, J.? B.; Weidenkaff, P.; Wen, S. ?P.; Werner, M.; Wiedner, U.; Wolke, M.; Wu, L.? H.; Wu, N.; Wu, Z.; Xia, L.? G.; Xia, Y.; Xiao, D.; Xiao, Z.? J.; Xie, Y.? G.; Xiu, Q.? L.; Xu, G.? F.; Xu, L.; Xu, Q. ?J.; Xu, Q.? N.; Xu, X.? P.; Xue, Z.; Yan, L.; Yan, W.? B.; Yan, W.? C.; Yan, Y.? H.; Yang, H.? X.; Yang, L.; Yang, Y.; Yang, Y.? X.; Ye, H.; Ye, M.; Ye, M.? H.; Yu, B. ?X.; Yu, C. ?X.; Yu, H.? W.; Yu, J.? S.; Yu, S.? P.; Yuan, C. ?Z.; Yuan, W.? L.; Yuan, Y.; Yuncu, A.; Zafar, A. ?A.; Zallo, A.; Zang, S.? L.; Zeng, Y.; Zhang, B. ?X.; Zhang, B.? Y.; Zhang, C.; Zhang, C. ?B.; Zhang, C.? C.; Zhang, D.? H.; Zhang, H.? H.; Zhang, H.? Y.; Zhang, J.? J.; Zhang, J.? Q.; Zhang, J.? W.; Zhang, J.? Y.; Zhang, J. ?Z.; Zhang, S.? H.; Zhang, X. ?J.; Zhang, X.? Y.; Zhang, Y.; Zhang, Y.? H.; Zhang, Z.? H.; Zhang, Z.? P.; Zhang, Z.? Y.; Zhao, G.

    2014-08-22

    The process e+e-?pp?0 has been studied by analyzing data collected at ?s=3.773 GeV, at s?=3.650 GeV, and during a ?(3770) line shape scan with the BESIII detector at the BEPCII collider. The Born cross section of pp?0 in the vicinity of the ?(3770) is measured, and the Born cross section of ?(3770)?pp?0 is extracted considering interference between resonant and continuum production amplitudes. Two solutions with the same probability and a significance of 1.5? are found. The solutions for the Born cross section of ?(3770)?pp?0 are 33.81.82.1 pb and 0.06+0.10-0.04+0.01-0.01 pb (<0.22 pb at a 90% confidence level). Using the estimated cross section and a constant decay amplitude approximation, the cross section ?(pp??(3770)?0) is calculated for the kinematic situation of the planned PANDA experiment. The maximum cross section corresponding to the two solutions is expected to be less than 0.79 nb at 90% confidence level and 12210 nb at a center-of-mass energy of 5.26 GeV.

  13. Mo99 Production Plant Layout

    SciTech Connect (OSTI)

    Woloshun, Keith Albert; Dale, Gregory E.; Naranjo, Angela Carol

    2015-06-25

    The NorthStar Medical Technologies 99Mo production facility configuration is envisioned to be 8 accelerator pairs irradiating 7 100Mo targets (one spare accelerator pair undergoing maintenance while the other 7 pairs are irradiating targets). The required shielding in every direction for the accelerators is initially estimated to be 10 feet of concrete. With the accelerator pairs on one (ground) level and spaced with the required shielding between adjacent pairs, the only practical path for target insertion and removal while minimizing floor space is vertical. The current scheme then requires a target vertical lift of nominally 10 feet through a shield stack. It is envisioned that the lift will be directly into a hot cell where an activated target can be removed from its holder and a new target attached and lowered. The hot cell is on a rail system so that a single hot cell can service all active target locations, as well as deliver the ready targets to the separations lab. On this rail system, coupled to the hot cell, will be a helium recovery and clean-up system. All helium coolant equipment is located on the upper level near to the target removal point.

  14. File:USDA-CE-Production-GIFmaps-IA.pdf | Open Energy Information

    Open Energy Info (EERE)

    IA.pdf Jump to: navigation, search File File history File usage Iowa Ethanol Plant Locations Size of this preview: 776 600 pixels. Full resolution (1,650 1,275 pixels,...

  15. Flames in Type Ia Supernova: Deflagration-Detonation Transition in the

    Office of Scientific and Technical Information (OSTI)

    Oxygen Burning Flame. (Journal Article) | SciTech Connect Journal Article: Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame. Citation Details In-Document Search Title: Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame. Abstract not provided. Authors: Kerstein, Alan R. ; Woosley, Stan E. ; Aspden, Andrew J. Publication Date: 2010-10-01 OSTI Identifier: 1121667 Report Number(s): SAND2010-7483J 485788 DOE

  16. Cosmological parameter uncertainties from SALT-II type Ia supernova light curve models

    SciTech Connect (OSTI)

    Mosher, J.; Sako, M. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Guy, J.; Astier, P.; Betoule, M.; El-Hage, P.; Pain, R.; Regnault, N. [LPNHE, CNRS/IN2P3, Universit Pierre et Marie Curie Paris 6, Universi Denis Diderot Paris 7, 4 place Jussieu, F-75252 Paris Cedex 05 (France); Kessler, R.; Frieman, J. A. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Marriner, J. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Biswas, R.; Kuhlmann, S. [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States); Schneider, D. P., E-mail: kessler@kicp.chicago.edu [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2014-09-20

    We use simulated type Ia supernova (SN Ia) samples, including both photometry and spectra, to perform the first direct validation of cosmology analysis using the SALT-II light curve model. This validation includes residuals from the light curve training process, systematic biases in SN Ia distance measurements, and a bias on the dark energy equation of state parameter w. Using the SN-analysis package SNANA, we simulate and analyze realistic samples corresponding to the data samples used in the SNLS3 analysis: ?120 low-redshift (z < 0.1) SNe Ia, ?255 Sloan Digital Sky Survey SNe Ia (z < 0.4), and ?290 SNLS SNe Ia (z ? 1). To probe systematic uncertainties in detail, we vary the input spectral model, the model of intrinsic scatter, and the smoothing (i.e., regularization) parameters used during the SALT-II model training. Using realistic intrinsic scatter models results in a slight bias in the ultraviolet portion of the trained SALT-II model, and w biases (w {sub input} w {sub recovered}) ranging from 0.005 0.012 to 0.024 0.010. These biases are indistinguishable from each other within the uncertainty; the average bias on w is 0.014 0.007.

  17. DOE - Office of Legacy Management -- Petrolite Corp - MO 08

    Office of Legacy Management (LM)

    Petrolite Corp - MO 08 FUSRAP Considered Sites Site: PETROLITE CORP (MO.08) Eliminated from further consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: St. Louis , Missouri MO.08-1 Evaluation Year: 1987 MO.08-4 Site Operations: Research involving test quantities of radioactive materials. MO.08-2 Site Disposition: Eliminated - Licensed - Potential for contamination remote MO.08-3 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled:

  18. Observation of a new charged charmoniumlike state inB<mo stretchy='false'>mo>>0mn> stretchy='false'>?mo>J<mo>/mo>?K<mo>-mo>?<mo>+>decays

    SciTech Connect (OSTI)

    Chilikin, K.; Mizuk, R.; Adachi, I.; Aihara, H.; Al Said, S.; Arinstein, K.; Asner, D.?M.; Aulchenko, V.; Aushev, T.; Ayad, R.; Aziz, T.; Bakich, A.?M.; Bansal, V.; Bondar, A.; Bonvicini, G.; Bozek, A.; Bra?ko, M.; Browder, T.?E.; ?ervenkov, D.; Chekelian, V.; Chen, A.; Cheon, B.?G.; Chistov, R.; Cho, K.; Chobanova, V.; Choi, S.-K.; Choi, Y.; Cinabro, D.; Danilov, M.; Doleal, Z.; Drsal, Z.; Drutskoy, A.; Dutta, K.; Eidelman, S.; Epifanov, D.; Farhat, H.; Fast, J.?E.; Ferber, T.; Frost, O.; Gaur, V.; Gabyshev, N.; Ganguly, S.; Garmash, A.; Gillard, R.; Goh, Y.?M.; Golob, B.; Grzymkowska, O.; Haba, J.; Hara, T.; Hayasaka, K.; Hayashii, H.; He, X.?H.; Hou, W.-S.; Huschle, M.; Hyun, H.?J.; Ishikawa, A.; Itoh, R.; Iwasaki, Y.; Jaegle, I.; Joo, K.?K.; Julius, T.; Kawasaki, T.; Kiesling, C.; Kim, D.?Y.; Kim, H.?J.; Kim, J.?H.; Kim, M.?J.; Kim, Y.?J.; Kinoshita, K.; Ko, B.?R.; Korpar, S.; Krian, P.; Krokovny, P.; Kuhr, T.; Kuzmin, A.; Kwon, Y.-J.; Lange, J.?S.; Li, Y.; Li Gioi, L.; Libby, J.; Liu, Y.; Liventsev, D.; Lukin, P.; Miyabayashi, K.; Miyata, H.; Mohanty, G.?B.; Moll, A.; Mori, T.; Mussa, R.; Nakano, E.; Nakao, M.; Nanut, T.; Natkaniec, Z.; Nedelkovska, E.; Nisar, N.?K.; Nishida, S.; Ogawa, S.; Okuno, S.; Olsen, S.?L.; Pakhlov, P.; Pakhlova, G.; Park, C.?W.; Park, H.; Pedlar, T.?K.; Petri?, M.; Piilonen, L.?E.; Ribel, E.; Ritter, M.; Rostomyan, A.; Sakai, Y.; Sandilya, S.; Santelj, L.; Sanuki, T.; Sato, Y.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Seon, O.; Shebalin, V.; Shen, C.?P.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Sibidanov, A.; Simon, F.; Sohn, Y.-S.; Sokolov, A.; Solovieva, E.; Stari?, M.; Steder, M.; Sumisawa, K.; Sumiyoshi, T.; Tamponi, U.; Tanida, K.; Tatishvili, G.; Teramoto, Y.; Thorne, F.; Trabelsi, K.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Urquijo, P.; Van Hulse, C.; Vanhoefer, P.; Varner, G.; Vinokurova, A.; Wagner, M.?N.; Wang, C.?H.; Wang, M.-Z.; Wang, P.; Wang, X.?L.; Watanabe, Y.; Wehle, S.; Williams, K.?M.; Won, E.; Yamaoka, J.; Yashchenko, S.; Zhang, Z.?P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.

    2014-12-16

    We present the results of an amplitude analysis of B0?J/?K-?+ decays. A new charged charmoniumlike state Zc(4200)+ decaying to J/??+ is observed with a significance of 6.2?. The mass and width of the Zc(4200)+ are 4196+31-29+17-13 MeV/c2 and 370+70-70+70-132 MeV, respectively; the preferred assignment of the quantum numbers is JP=1+. In addition, we find evidence for Zc(4430)+?J/??+. The analysis is based on a 711 fb-1 data sample collected by the Belle detector at the asymmetric-energy e+e- collider KEKB.

  19. Measurement of the target-normal single-spin asymmetry in quasielastic scattering from the reaction He<mn>3mn> stretchy='false'>?mo> stretchy='false'>(mo>e<mo>,mo>e<mo>' stretchy='false'>)mo>

    SciTech Connect (OSTI)

    Zhang, Y. -W.; Long, E.; Mihovilovi?, M.; Jin, G.; Allada, K.; Anderson, B.; Annand, J. R. M.; Averett, T.; Ayerbe-Gayoso, C.; Boeglin, W.; Bradshaw, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J. P.; Chudakov, E.; De Leo, R.; Deng, X.; Deur, A.; Dutta, C.; El Fassi, L.; Flay, D.; Frullani, S.; Garibaldi, F.; Gao, H.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Gomez, J.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, J.; Ibrahim, H.; de Jager, C. W.; Jensen, E.; Jiang, X.; John, J. St.; Jones, M.; Kang, H.; Katich, J.; Khanal, H. P.; King, P.; Korsch, W.; LeRose, J.; Lindgren, R.; Lu, H. -J.; Luo, W.; Markowitz, P.; Meziane, M.; Michaels, R.; Moffit, B.; Monaghan, P.; Muangma, N.; Nanda, S.; Norum, B. E.; Pan, K.; Parno, D.; Piasetzky, E.; Posik, M.; Punjabi, V.; Puckett, A. J. R.; Qian, X.; Qiang, Y.; Qiu, X.; Riordan, S.; Ron, G.; Saha, A.; Sawatzky, B.; Schiavilla, R.; Schoenrock, B.; Shabestari, M.; Shahinyan, A.; irca, S.; Subedi, R.; Sulkosky, V.; Tobias, W. A.; Tireman, W.; Urciuoli, G. M.; Wang, D.; Wang, K.; Wang, Y.; Watson, J.; Wojtsekhowski, B.; Ye, Z.; Zhan, X.; Zhang, Y.; Zheng, X.; Zhao, B.; Zhu, L.

    2015-10-22

    We report the first measurement of the target single-spin asymmetry, Ay, in quasi-elastic scattering from the inclusive reaction 3He? (e,e') on a 3He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A non-zero Ay can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the sub-structure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at Q2= 0.13, 0.46 and 0.97 GeV2. These measurements demonstrate, for the first time, that the 3He asymmetry is clearly non-zero and negative with a statistical significance of (8-10)?. Using measured proton-to-3He cross-section ratios and the effective polarization approximation, neutron asymmetries of -(1-3)% were obtained. The neutron asymmetry at high Q2 is related to moments of the Generalized Parton Distributions (GPDs). Our measured neutron asymmetry at Q2=0.97 GeV2 agrees well with a prediction based on two-photon exchange using a GPD model and in addition provides a new independent constraint on these distributions.

  20. Missouri Department of National Resources Energy Center Mo DNR...

    Open Energy Info (EERE)

    Department of National Resources Energy Center Mo DNR Jump to: navigation, search Name: Missouri Department of National Resources Energy Center (Mo DNR) Place: Jefferson City,...

  1. Demonstration of LED Street Lighting in Kansas City, MO (Technical...

    Office of Scientific and Technical Information (OSTI)

    Report: Demonstration of LED Street Lighting in Kansas City, MO Citation Details In-Document Search Title: Demonstration of LED Street Lighting in Kansas City, MO Nine different ...

  2. Materials Data on BaLaMnMoO6 (SG:216) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2015-03-19

    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

  3. Mn deposition on Ni{sub 2}MnGa(100) (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Mn deposition on Ni{sub 2}MnGa(100) Citation Details In-Document Search Title: Mn deposition on Ni{sub 2}MnGa(100) We report the study of Mn adlayers on a Mn deficient Ni{sub 2}MnGa(100) surface by using low energy electron diffraction (LEED). The spot profile analysis indicates that after 0.2 monolayer (ML) deposition, the LEED spots become very sharp. This pattern indicates the removal of Mn vacancies formed on the surface due to Mn deficiency. But with further growth of Mn layers on this

  4. Type Ia supernovae from merging white dwarfs. II. Post-merger detonations

    SciTech Connect (OSTI)

    Raskin, Cody; Kasen, Daniel [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Moll, Rainer; Woosley, Stan [Department of Physics and Department of Astronomy, University of California, Santa Cruz, CA (United States); Schwab, Josiah [Department of Physics and Department of Astronomy, University of California, Berkeley, CA (United States)

    2014-06-10

    Merging carbon-oxygen (CO) white dwarfs are a promising progenitor system for Type Ia supernovae (SNe Ia), but the underlying physics and timing of the detonation are still debated. If an explosion occurs after the secondary star is fully disrupted, the exploding primary will expand into a dense CO medium that may still have a disk-like structure. This interaction will decelerate and distort the ejecta. Here we carry out multidimensional simulations of 'tamped' SN Ia models, using both particle and grid-based codes to study the merger and explosion dynamics and a radiative transfer code to calculate synthetic spectra and light curves. We find that post-merger explosions exhibit an hourglass-shaped asymmetry, leading to strong variations in the light curves with viewing angle. The two most important factors affecting the outcome are the scale height of the disk, which depends sensitively on the binary mass ratio, and the total {sup 56}Ni yield, which is governed by the central density of the remnant core. The synthetic broadband light curves rise and decline very slowly, and the spectra generally look peculiar, with weak features from intermediate mass elements but relatively strong carbon absorption. We also consider the effects of the viscous evolution of the remnant and show that a longer time delay between merger and explosion probably leads to larger {sup 56}Ni yields and more symmetrical remnants. We discuss the relevance of this class of aspherical 'tamped' SN Ia for explaining the class of 'super-Chandrasekhar' SN Ia.

  5. Microsoft Word - Mn.doc

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

    5 Structural Determination of Marine Bacteriogenic Manganese Oxides John R. Bargar, Samuel M. Webb (Stanford Synchrotron Radiation Laboratory), and Bradley M. Tebo (Oregon Health and Science University) Bacterial oxidation of Mn(II) impacts the global geochemical cycling of carbon, nitrogen, sulfur, nutrients, and contaminants in the environment. Manganese is abundant in the biosphere (~10 14 Kg of suspended and dissolved manganese in the oceans) and is second only to iron in relative

  6. Release on M&O Selection Final

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

    Federal Services LLC, of Bethesda, Maryland) has been awarded a 1.3 billion contract for management and operating (M&O) at DOE's Waste Isolation Pilot Plant (WIPP) in Carlsbad,...

  7. Ultraviolet observations of Super-Chandrasekhar mass type Ia supernova candidates with swift UVOT

    SciTech Connect (OSTI)

    Brown, Peter J.; Smitka, Michael T.; Krisciunas, Kevin; Wang, Lifan [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); Kuin, Paul; De Pasquale, Massimiliano [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking Surrey, RH5 6NT (United Kingdom); Scalzo, Richard [Research School of Astronomy and Astrophysics, The Australian National University, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Holland, Stephen [Space Telescope Science Center 3700 San Martin Drive, Baltimore, MD 21218 (United States); Milne, Peter, E-mail: pbrown@physics.tamu.edu [Steward Observatory, University of Arizona, Tucson, AZ 85719 (United States)

    2014-05-20

    Among Type Ia supernovae (SNe Ia), a class of overluminous objects exist whose ejecta mass is inferred to be larger than the canonical Chandrasekhar mass. We present and discuss the UV/optical photometric light curves, colors, absolute magnitudes, and spectra of three candidate Super-Chandrasekhar mass SNe2009dc, 2011aa, and 2012dnobserved with the Swift Ultraviolet/Optical Telescope. The light curves are at the broad end for SNe Ia, with the light curves of SN 2011aa being among the broadest ever observed. We find all three to have very blue colors which may provide a means of excluding these overluminous SNe from cosmological analysis, though there is some overlap with the bluest of 'normal' SNe Ia. All three are overluminous in their UV absolute magnitudes compared to normal and broad SNe Ia, but SNe 2011aa and 2012dn are not optically overluminous compared to normal SNe Ia. The integrated luminosity curves of SNe 2011aa and 2012dn in the UVOT range (1600-6000 ) are only half as bright as SN 2009dc, implying a smaller {sup 56}Ni yield. While it is not enough to strongly affect the bolometric flux, the early time mid-UV flux makes a significant contribution at early times. The strong spectral features in the mid-UV spectra of SNe 2009dc and 2012dn suggest a higher temperature and lower opacity to be the cause of the UV excess rather than a hot, smooth blackbody from shock interaction. Further work is needed to determine the ejecta and {sup 56}Ni masses of SNe 2011aa and 2012dn and to fully explain their high UV luminosities.

  8. Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching

    Office of Scientific and Technical Information (OSTI)

    for prompt explosions in the early universe (Journal Article) | SciTech Connect Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching for prompt explosions in the early universe Citation Details In-Document Search Title: Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching for prompt explosions in the early universe The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space

  9. Type Ia supernovae yielding distances with 3-4% precision (Journal Article)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Type Ia supernovae yielding distances with 3-4% precision Citation Details In-Document Search Title: Type Ia supernovae yielding distances with 3-4% precision × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of this

  10. Comprehensive amplitude analysis of γγ<mo stretchy='false'>→mo>π<mo>+mo>π<mo>-,π>0mn>π>0mn> and K<mo accent='true' stretchy='true'>¯mo>K below 1.5 GeV

    SciTech Connect (OSTI)

    Dai, Ling-Yun; Pennington, Michael R.

    2014-08-15

    In this paper we perform an amplitude analysis of essentially all published pion and kaon pair production data from two photon collisions below 1.5 GeV. This includes all the high statistics results from Belle, as well as older data from Mark II at SLAC, CELLO at DESY, Crystal Ball at SLAC. The purpose of this analysis is to provide as close to a model-independent determination of the γγ to meson pair amplitudes as possible. Having data with limited angular coverage, typically |cosθ| < 0.6-0.8, and no polarization information for reactions in which spin is an essential complication, the determination of the underlying amplitudes might appear an intractable problem. However, imposing the basic constraints required by analyticity, unitarity, and crossing-symmetry makes up for the experimentally missing information. Above 1.5 GeV multi-meson production channels become important and we have too little information to resolve the amplitudes. Nevertheless, below 1.5 GeV the two photon production of hadron pairs serves as a paradigm for the application of S-matrix techniques. Final state interactions among the meson pairs is critical to this analysis. To fix these, we include the latest ππ → ππ, K⁻K scattering amplitudes given by dispersive analyses, supplemented in the K⁻K threshold region by the recent precision Dalitz plot analysis from BaBar. With these hadronic amplitudes built into unitarity, we can constrain the overall description of γγ → ππ and K⁻K datasets, both integrated and differential cross-sections, including the high statistics charged and neutral pion data from Belle. A region of solutions is found for the γγ → ππ partial waves with both isospin 0 and 2. Since this analysis invokes coupled hadronic channels, even the relatively poor integrated cross-section data on γγ → K⁻K narrows the patch of solutions to essentially a single form. For this we present the complete partial wave amplitudes, show how well they fit all the available data, and give the two photon couplings of scalar and tensor resonances that appear.

  11. Search for proton decay via p<mo stretchy='false'>?mo>?K<mo>+> using <mn>260mn> kiloton<mo>>year data of Super-Kamiokande

    SciTech Connect (OSTI)

    Abe, K.; Hayato, Y.; Iyogi, K.; Kameda, J.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakayama, S.; Wendell, R.?A.; Sekiya, H.; Shiozawa, M.; Suzuki, Y.; Takeda, A.; Takenaga, Y.; Ueno, K.; Yokozawa, T.; Kaji, H.; Kajita, T.; Kaneyuki, K.; Lee, K.?P.; Okumura, K.; McLachlan, T.; Labarga, L.; Kearns, E.; Raaf, J.?L.; Stone, J.?L.; Sulak, L.?R.; Goldhaber, M.; Bays, K.; Carminati, G.; Kropp, W.?R.; Mine, S.; Renshaw, A.; Smy, M.?B.; Sobel, H.?W.; Ganezer, K.?S.; Hill, J.; Keig, W.?E.; Jang, J.?S.; Kim, J.?Y.; Lim, I.?T.; Albert, J.?B.; Scholberg, K.; Walter, C.?W.; Wongjirad, T.; Ishizuka, T.; Tasaka, S.; Learned, J.?G.; Matsuno, S.; Smith, S.?N.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Nishikawa, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Suzuki, A.?T.; Takeuchi, Y.; Ieki, K.; Ikeda, M.; Kubo, H.; Minamino, A.; Murakami, A.; Nakaya, T.; Fukuda, Y.; Choi, K.; Itow, Y.; Mitsuka, G.; Miyake, M.; Mijakowski, P.; Hignight, J.; Imber, J.; Jung, C.?K.; Taylor, I.; Yanagisawa, C.; Ishino, H.; Kibayashi, A.; Koshio, Y.; Mori, T.; Sakuda, M.; Takeuchi, J.; Kuno, Y.; Kim, S.?B.; Okazawa, H.; Choi, Y.; Nishijima, K.; Koshiba, M.; Totsuka, Y.; Yokoyama, M.; Martens, K.; Marti, Ll.; Obayashi, Y.; Vagins, M.?R.; Chen, S.; Sui, H.; Yang, Z.; Zhang, H.; Connolly, K.; Dziomba, M.; Wilkes, R.?J.

    2014-10-14

    We have searched for proton decay via p??K+ using Super-Kamiokande data from April 1996 to February 2013, 260 kilotonyear exposure in total. No evidence for this proton decay mode is found. A lower limit of the proton lifetime is set to ?/B(p??K+)>5.91033 years at 90% confidence level.

  12. DOE - Office of Legacy Management -- Elk River Reactor - MN 01

    Office of Legacy Management (LM)

    Elk River Reactor - MN 01 FUSRAP Considered Sites Site: Elk River Reactor (MN.01 ) Eliminated from consideration under FUSRAP - Reactor was dismantled and decommissioned by 1974 Designated Name: Not Designated Alternate Name: None Location: Elk River , Minnesota MN.01-1 Evaluation Year: 1985 MN.01-1 Site Operations: Boiling water reactor demonstration, research and development program MN.01-1 Site Disposition: Eliminated MN.01-1 Radioactive Materials Handled: None Indicated Primary Radioactive

  13. Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

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

    Hsiao, E. Y.; Burns, C. R.; Contreras, C.; Höflich, P.; Sand, D.; Marion, G. H.; Phillips, M. M.; Stritzinger, M.; González-Gaitán, S.; Mason, R. E.; et al

    2015-05-22

    We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR C I lines, and the C Iλ1.0693 μm line is the strongest ever observed in a SN Ia. Interestingly, no strong optical C II counterparts were found, even though themore » optical spectroscopic time series began early and is densely cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR C I compared to the weaker optical C II appears to be general in SNe Ia. iPTF13ebh is a fast decliner with Δm15(B) = 1.79 ± 0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categorized as a “transitional” event, on the fast-declining end of normal SNe Ia as opposed to subluminous/91bg-like objects. iPTF13ebh shows NIR spectroscopic properties that are distinct from both the normal and subluminous/91bg-like classes, bridging the observed characteristics of the two classes. These NIR observations suggest that composition and density of the inner core are similar to that of 91bg-like events, and that it has a deep-reaching carbon burning layer that is not observed in more slowly declining SNe Ia. Furthermore, there is also a substantial difference between the explosion times inferred from the early-time light curve and the velocity evolution of the Si II λ0.6355 μm line, implying a long dark phase of ~4 days.« less

  14. Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

    SciTech Connect (OSTI)

    Hsiao, E. Y.; Burns, C. R.; Contreras, C.; Hflich, P.; Sand, D.; Marion, G. H.; Phillips, M. M.; Stritzinger, M.; Gonzlez-Gaitn, S.; Mason, R. E.; Folatelli, G.; Parent, E.; Gall, C.; Amanullah, R.; Anupama, G. C.; Arcavi, I.; Banerjee, D. P. K.; Beletsky, Y.; Blanc, G. A.; Bloom, J. S.; Brown, P. J.; Campillay, A.; Cao, Y.; De Cia, A.; Diamond, T.; Freedman, W. L.; Gonzalez, C.; Goobar, A.; Holmbo, S.; Howell, D. A.; Johansson, J.; Kasliwal, M. M.; Kirshner, R. P.; Krisciunas, K.; Kulkarni, S. R.; Maguire, K.; Milne, P. A.; Morrell, N.; Nugent, P. E.; Ofek, E. O.; Osip, D.; Palunas, P.; Perley, D. A.; Persson, S. E.; Piro, A. L.; Rabus, M.; Roth, M.; Schiefelbein, J. M.; Srivastav, S.; Sullivan, M.; Suntzeff, N. B.; Surace, J.; Wo?niak, P. R.; Yaron, O.

    2015-05-22

    We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR C I lines, and the C I?1.0693 ?m line is the strongest ever observed in a SN Ia. Interestingly, no strong optical C II counterparts were found, even though the optical spectroscopic time series began early and is densely cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR C I compared to the weaker optical C II appears to be general in SNe Ia. iPTF13ebh is a fast decliner with ?m15(B) = 1.79 0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categorized as a transitional event, on the fast-declining end of normal SNe Ia as opposed to subluminous/91bg-like objects. iPTF13ebh shows NIR spectroscopic properties that are distinct from both the normal and subluminous/91bg-like classes, bridging the observed characteristics of the two classes. These NIR observations suggest that composition and density of the inner core are similar to that of 91bg-like events, and that it has a deep-reaching carbon burning layer that is not observed in more slowly declining SNe Ia. Furthermore, there is also a substantial difference between the explosion times inferred from the early-time light curve and the velocity evolution of the Si II ?0.6355 ?m line, implying a long dark phase of ~4 days.

  15. Elevated Temperature Tensile Tests on DU10Mo Rolled Foils

    SciTech Connect (OSTI)

    Schulthess, Jason

    2014-09-01

    Tensile mechanical properties for uranium-10 wt.% molybdenum (U10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU10Mo) mechanical behavior is representative of the low enriched U10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

  16. Role of Ce<mn>4mn>+> in the scintillation mechanism of codoped Gd<mn>3mn>Ga<mn>3mn>Al<mn>2mn>O<mn>12mn>:>Ce

    SciTech Connect (OSTI)

    Wu, Yuntao; Meng, Fang; Li, Qi; Koschan, Merry; Melcher, Charles L.

    2014-10-17

    To control the time-response performance of widely used cerium-activated scintillators in cutting-edge medical-imaging devices, such as time-of-flight positron-emission tomography, a comprehensive understanding of the role of Ce valence states, especially stable Ce4+, in the scintillation mechanism is essential. However, despite some progress made recently, an understanding of the physical processes involving Ce4+ is still lacking. The aim of this work is to clarify the role of Ce4+ in scintillators by studying Ca2+ codoped Gd3Ga3Al2O12?Ce?(GGAG?Ce). By using a combination of optical absorption spectra and x-ray absorption near-edge spectroscopies, the correlation between Ca2+codoping content and the Ce4+ fraction is seen. The energy-level diagrams of Ce3+ and Ce4+ in the Gd3Ga3Al2O12 host are established by using theoretical and experimental methods, which indicate a higher position of the 5d1 state of Ce4+ in the forbidden gap in comparison to that of Ce3+. Underlying reasons for the decay-time acceleration resulting from Ca2+ codoping are revealed, and the physical processes of the Ce4+-emission model are proposed and further demonstrated by temperature-dependent radioluminescence spectra under x-ray excitation.

  17. TYPE Ia SUPERNOVA COLORS AND EJECTA VELOCITIES: HIERARCHICAL BAYESIAN REGRESSION WITH NON-GAUSSIAN DISTRIBUTIONS

    SciTech Connect (OSTI)

    Mandel, Kaisey S.; Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Foley, Ryan J., E-mail: kmandel@cfa.harvard.edu [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States)

    2014-12-20

    We investigate the statistical dependence of the peak intrinsic colors of Type Ia supernovae (SNe Ia) on their expansion velocities at maximum light, measured from the Si II ?6355 spectral feature. We construct a new hierarchical Bayesian regression model, accounting for the random effects of intrinsic scatter, measurement error, and reddening by host galaxy dust, and implement a Gibbs sampler and deviance information criteria to estimate the correlation. The method is applied to the apparent colors from BVRI light curves and Si II velocity data for 79 nearby SNe Ia. The apparent color distributions of high-velocity (HV) and normal velocity (NV) supernovae exhibit significant discrepancies for B V and B R, but not other colors. Hence, they are likely due to intrinsic color differences originating in the B band, rather than dust reddening. The mean intrinsic B V and B R color differences between HV and NV groups are 0.06 0.02 and 0.09 0.02 mag, respectively. A linear model finds significant slopes of 0.021 0.006 and 0.030 0.009 mag (10{sup 3} km s{sup 1}){sup 1} for intrinsic B V and B R colors versus velocity, respectively. Because the ejecta velocity distribution is skewed toward high velocities, these effects imply non-Gaussian intrinsic color distributions with skewness up to +0.3. Accounting for the intrinsic-color-velocity correlation results in corrections to A{sub V} extinction estimates as large as 0.12 mag for HV SNe Ia and +0.06 mag for NV events. Velocity measurements from SN Ia spectra have the potential to diminish systematic errors from the confounding of intrinsic colors and dust reddening affecting supernova distances.

  18. Oxidation, Reduction, and Condensation of Alcohols over (MO3)3 (M=Mo, W) Nanoclusters

    SciTech Connect (OSTI)

    Fang, Zongtang; Li, Zhenjun; Kelley, Matthew S.; Kay, Bruce D.; Li, Shenggang; Hennigan, Jamie M.; Rousseau, Roger J.; Dohnalek, Zdenek; Dixon, David A.

    2014-10-02

    The reactions of deuterated methanol, ethanol, 1-propanol, 1-butanol, 2-propanol, 2-butanol and t-butanol over cyclic (MO3)3 (M = Mo, W) clusters were studied experimentally with temperature programmed desorption (TPD) and theoretically with coupled cluster CCSD(T) theory and density functional theory. The reactions of two alcohols per M3O9 cluster are required to provide agreement with experiment for D2O release, dehydrogenation and dehydration. The reaction begins with the elimination of water by proton transfers and forms an intermediate dialkoxy species which can undergo further reaction. Dehydration proceeds by a ? hydrogen transfer to a terminal M=O. Dehydrogenation takes place via an ? hydrogen transfer to an adjacent MoVI = O atom or a WVI metal center with redox involved for M = Mo and no redox for M = W. The two channels have comparable activation energies. H/D exchange to produce alcohols can take place after olefin is released or via the dialkoxy species depending on the alcohol and the cluster. The Lewis acidity of the metal center with WVI being larger than MoVI results in the increased reactivity of W3O9 over Mo3O9 for dehydrogenation and dehydration.

  19. Temperature and composition phase diagram in the iron-based ladder compounds Ba <mn>1mn> <mo>-> x Cs x Fe <mn>2mn> Se <mn>3mn>

    SciTech Connect (OSTI)

    Hawai, Takafumi; Nambu, Yusuke; Ohgushi, Kenya; Du, Fei; Hirata, Yasuyuki; Avdeev, Maxim; Uwatoko, Yoshiya; Sekine, Yurina; Fukazawa, Hiroshi; Ma, Jie; Chi, Songxue; Ueda, Yutaka; Yoshizawa, Hideki; Sato, Taku J.

    2015-05-28

    We investigated the iron-based ladder compounds (Ba,Cs)Fe?Se?. Their parent compounds BaFe?Se? and CsFe?Se? have different space groups, formal valences of Fe, and magnetic structures. Electrical resistivity, specific heat, magnetic susceptibility, x-ray diffraction, and powder neutron diffraction measurements were conducted to obtain a temperature and composition phase diagram of this system. Block magnetism observed in BaFe?Se? is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFe?Se? is not so fragile against Ba doping. A new type of magnetic structure appears in intermediate compositions, which is similar to stripe magnetism of CsFe?Se?, but interladder spin configuration is different. Intermediate compounds show insulating behavior, nevertheless a finite T-linear contribution in specific heat was obtained at low temperatures.

  20. Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching for prompt explosions in the early universe

    SciTech Connect (OSTI)

    Rodney, Steven A.; Riess, Adam G.; Graur, Or; Jones, David O. [Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218 (United States); Strolger, Louis-Gregory; Dahlen, Tomas; Casertano, Stefano; Ferguson, Henry C.; Koekemoer, Anton M. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Dickinson, Mark E. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Garnavich, Peter [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Hayden, Brian [E.O. Lawrence Berkeley National Lab, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Jha, Saurabh W.; McCully, Curtis; Patel, Brandon [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Mobasher, Bahram [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Weiner, Benjamin J. [Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Clubb, Kelsey I. [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); and others

    2014-07-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space Telescope (HST) that surveyed a total area of ?0.25 deg{sup 2} with ?900 HST orbits spread across five fields over three years. Within these survey images we discovered 65 supernovae (SNe) of all types, out to z ? 2.5. We classify ?24 of these as Type Ia SNe (SNe Ia) based on host galaxy redshifts and SN photometry (supplemented by grism spectroscopy of six SNe). Here we present a measurement of the volumetric SN Ia rate as a function of redshift, reaching for the first time beyond z = 2 and putting new constraints on SN Ia progenitor models. Our highest redshift bin includes detections of SNe that exploded when the universe was only ?3 Gyr old and near the peak of the cosmic star formation history. This gives the CANDELS high redshift sample unique leverage for evaluating the fraction of SNe Ia that explode promptly after formation (<500 Myr). Combining the CANDELS rates with all available SN Ia rate measurements in the literature we find that this prompt SN Ia fraction is f{sub P} = 0.53{sub stat0.10}{sup 0.09}{sub sys0.26}{sup 0.10}, consistent with a delay time distribution that follows a simple t {sup 1} power law for all times t > 40 Myr. However, mild tension is apparent between ground-based low-z surveys and space-based high-z surveys. In both CANDELS and the sister HST program CLASH (Cluster Lensing And Supernova Survey with Hubble), we find a low rate of SNe Ia at z > 1. This could be a hint that prompt progenitors are in fact relatively rare, accounting for only 20% of all SN Ia explosionsthough further analysis and larger samples will be needed to examine that suggestion.

  1. Accelerator Production Options for 99MO

    SciTech Connect (OSTI)

    Bertsche, Kirk; /SLAC

    2010-08-25

    Shortages of {sup 99}Mo, the most commonly used diagnostic medical isotope, have caused great concern and have prompted numerous suggestions for alternate production methods. A wide variety of accelerator-based approaches have been suggested. In this paper we survey and compare the various accelerator-based approaches.

  2. MOED_of_the_Italian_Republic.PDF | Department of Energy

    Office of Environmental Management (EM)

    MOED_of_the_Italian_Republic.PDF MOED_of_the_Italian_Republic.PDF PDF icon MOED_of_the_Italian_Republic.PDF More Documents & Publications Scanned_Agreement.pdf International_Agreements_January_2001_December_2004.pdf Implementing Arrangement Between DOE and METI on R&D Cooperation on Clean Energy Technology - April 2015

  3. Role of SrMoO{sub 4} in Sr{sub 2}MgMoO{sub 6} synthesis

    SciTech Connect (OSTI)

    Vasala, S.; Yamauchi, H.; Karppinen, M.

    2011-05-15

    Here we investigate the elemental and phase compositions during the solid-state synthesis of the promising SOFC-anode material, Sr{sub 2}MgMoO{sub 6}, and demonstrate that molybdenum does not notably evaporate under the normal synthesis conditions with temperatures up to 1200 {sup o}C due to the formation of SrMoO{sub 4} as an intermediate product at low temperatures, below 600 {sup o}C. However, partial decomposition of the Sr{sub 2}MgMoO{sub 6} phase becomes evident at the higher temperatures ({approx}1500 {sup o}C). The effect of SrMoO{sub 4} on the electrical conductivity of Sr{sub 2}MgMoO{sub 6} is evaluated by preparing a series of Sr{sub 2}MgMoO{sub 6} samples with different amounts of additional SrMoO{sub 4}. Under the reducing operation conditions of an SOFC anode the insulating SrMoO{sub 4} phase is apparently reduced to the highly conductive SrMoO{sub 3} phase. Percolation takes place with 20-30 wt% of SrMoO{sub 4} in a Sr{sub 2}MgMoO{sub 6} matrix, with a notable increase in electrical conductivity after reduction. Conductivity values of 14, 60 and 160 S/cm are determined at 800 {sup o}C in 5% H{sub 2}/Ar for the Sr{sub 2}MgMoO{sub 6} samples with 30, 40 and 50 wt% of added SrMoO{sub 4}, respectively. -- Graphical abstract: SrMoO{sub 4} is formed at low temperatures during the synthesis of Sr{sub 2}MgMoO{sub 6}, which prevents the volatilization of Mo from typical precursor mixtures of this promising SOFC anode material. SrMoO{sub 4} is insulating and it is often found as an impurity in Sr{sub 2}MgMoO{sub 6} samples. It is however readily reduced to highly conducting SrMoO{sub 3}. Composites of Sr{sub 2}MgMoO{sub 6} and SrMoO{sub 3} show increased electrical conductivities compared to pure Sr{sub 2}MgMoO{sub 6} under the reductive operation conditions of an SOFC anode. Display Omitted Highlights: {yields} Sr{sub 2}MgMoO{sub 6} is a promising SOFC anode material. {yields} During the Sr{sub 2}MgMoO{sub 6} synthesis SrMoO{sub 4} is formed at low temperatures. {yields} Formation of SrMoO{sub 4} effectively prevents volatilization of Mo at high temperatures. {yields} Insulating SrMoO{sub 4} reduces to highly conductive SrMoO{sub 3} under SOFC-anode conditions. {yields} Composites of Sr{sub 2}MgMoO{sub 6} and SrMoO{sub 3} show high electrical conductivities.

  4. SNe Ia tests of quintessence tracker cosmology in an anisotropic background

    SciTech Connect (OSTI)

    Miranda, W.; Carneiro, S.; Pigozzo, C. E-mail: saulo.carneiro@pq.cnpq.br

    2014-07-01

    We investigate the observational effects of a quintessence model in an anisotropic spacetime. The anisotropic metric is a non-rotating particular case of a generalized Gdel's metric and is classified as Bianchi III. This metric is an exact solution of the Einstein-Klein-Gordon field equations with an anisotropic scalar field ?, which is responsible for the anisotropy of the spacetime geometry. We test the model against observations of type Ia supernovae, analyzing the SDSS dataset calibrated with the MLCS2k2 fitter, and the results are compared to standard quintessence models with Ratra-Peebles potentials. We obtain a good agreement with observations, with best values for the matter and curvature density parameters ?{sub M}=0.29 and ?{sub k}=0.01 respectively. We conclude that present SNe Ia observations cannot, alone, distinguish a possible anisotropic axis in the cosmos.

  5. Comparing the host galaxies of type Ia, type II, and type Ibc supernovae

    SciTech Connect (OSTI)

    Shao, X.; Liang, Y. C.; Chen, X. Y.; Zhong, G. H.; Deng, L. C.; Zhang, B.; Shi, W. B.; Zhou, L.; Dennefeld, M.; Hammer, F.; Flores, H. E-mail: ycliang@bao.ac.cn

    2014-08-10

    We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the Sloan Digital Sky Survey (SDSS) Data Release 7. We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters D{sub n}(4000), H?{sub A}, stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low D{sub n}(4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high D{sub n}(4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (?0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.

  6. SSL Demonstration: Bridge Lighting, Minneapolis, MN

    SciTech Connect (OSTI)

    2014-10-01

    DOE Solid-State Lighting GATEWAY summary brief for Phase II report on the longer-term performance of LED lighting installed in 2008 on the I-35W Bridge in Minneapolis, MN.

  7. Optical and ultraviolet observations of the narrow-lined type Ia SN 2012fr in NGC 1365

    SciTech Connect (OSTI)

    Zhang, Ju-Jia; Bai, Jin-Ming; Wang, Bo; Liu, Zheng-Wei [Yunnan Observatories (YNAO), Chinese Academy of Sciences, Kunming 650011 (China); Wang, Xiao-Feng; Zhao, Xu-Lin; Chen, Jun-Cheng [Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing 100084 (China); Zhang, Tian-Meng, E-mail: jujia@ynao.ac.cn, E-mail: baijinming@ynao.ac.cn, E-mail: wang_xf@mail.tsinghua.edu.cn [National Astronomical Observatories of China (NAOC), Chinese Academy of Sciences, Beijing 100012 (China)

    2014-07-01

    Extensive optical and ultraviolet (UV) observations of the type Ia supernova (SN Ia) 2012fr are presented in this paper. It has a relatively high luminosity, with an absolute B-band peak magnitude of about 19.5 mag and a smaller post-maximum decline rate than normal SNe Ia (e.g., ?m {sub 15}(B) =0.85 0.05 mag). Based on the UV and optical light curves, we derived that a {sup 56}Ni mass of about 0.88 M {sub ?} was synthesized in the explosion. The earlier spectra are characterized by noticeable high-velocity features of Si II ?6355 and Ca II with velocities in the range of ?22, 000-25, 000 km s{sup 1}. At around the maximum light, these spectral features are dominated by the photospheric components which are noticeably narrower than normal SNe Ia. The post-maximum velocity of the photosphere remains almost constant at ?12,000 km s{sup 1} for about one month, reminiscent of the behavior of some luminous SNe Ia like SN 1991T. We propose that SN 2012fr may represent a subset of the SN 1991T-like SNe Ia viewed in a direction with a clumpy or shell-like structure of ejecta, in terms of a significant level of polarization reported in Maund et al. in 2013.

  8. Measurement of Double-Polarization Asymmetries in the Quasielastic He<mo stretchy='true'>?mo>>3mn> stretchy='false'>(mo>e<mo stretchy='false'>?mo><mo>,mo>e<mo>'d stretchy='false'>)mo> Process

    SciTech Connect (OSTI)

    Mihovilovic, M.; Jin, G.; Long, E.; Zhang, Y. -W.; Allada, K.; Anderson, B.; Annand, J. R.M.; Averett, T.; Boeglin, W.; Bradshaw, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J. P.; Chudakov, E.; De Leo, R.; Deng, X.; Deltuva, A.; Deur, A.; Dutta, C.; El Fassi, L.; Flay, D.; Frullani, S.; Garibaldi, F.; Gao, H.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golak, J.; Golge, S.; Gomez, J.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, J.; Ibrahim, H.; de Jager, C. W.; Jensen, E.; Jiang, X.; Jones, M.; Kang, H.; Katich, J.; Khanal, H. P.; Kievsky, A.; King, P.; Korsch, W.; LeRose, J.; Lindgren, R.; Lu, H. -J.; Luo, W.; Marcucci, L. E.; Markowitz, P.; Meziane, M.; Michaels, R.; Moffit, B.; Monaghan, P.; Muangma, N.; Nanda, S.; Norum, B. E.; Pan, K.; Parno, D.; Piasetzky, E.; Posik, M.; Punjabi, V.; Puckett, A. J.R.; Qian, X.; Qiang, Y.; Qui, X.; Riordan, S.; Saha, A.; Sauer, P. U.; Sawatzky, B.; Schiavilla, R.; Schoenrock, B.; Shabestari, M.; Shahinyan, A.; Sirca, S.; Skibinski, R.; St John, J.; Subedi, R.; Sulkosky, V.; Tobias, W. A.; Tireman, W.; Urciuoli, G. M.; Viviani, M.; Wang, D.; Wang, K.; Wang, Y.; Watson, J.; Wojtsekhowski, B.; Witala, H.; Ye, Z.; Zhan, X.; Zhang, Y.; Zheng, X.; Zhao, B.; Zhu, L.

    2014-12-05

    We present a precise measurement of double-polarization asymmetries in the 3He(e,e'd) reaction. This particular process is a uniquely sensitive probe of hadron dynamics in 3He and the structure of the underlying electromagnetic currents. The measurements have been performed in and around quasi-elastic kinematics at Q2=0.25(GeV/c)2 for missing momenta up to 270MeV/c. The asymmetries are in fair agreement with the state-of-the-art calculations in terms of their functional dependencies on pm and omega, but are systematically offset. Beyond the region of the quasi-elastic peak, the discrepancies become even more pronounced. Thus, our measurements have been able to reveal deficiencies in the most sophisticated calculations of the three-body nuclear system, and indicate that further refinement in the treatment of their two- and/or three-body dynamics is required.

  9. DOE - Office of Legacy Management -- St Louis Downtown Site - MO 02

    Office of Legacy Management (LM)

    Downtown Site - MO 02 FUSRAP Considered Sites St. Louis Downtown, MO Alternate Name(s): Destrehan Street Plant Downtown Site Mallinckrodt Chemical Plant Mallinckrodt Chemical Works MO.02-1 MO.02-3 Location: 65 Destrehan Street, St. Louis, Missouri MO.02-5 Historical Operations: Conducted uranium metal and uranium oxides research, development, and production for MED and AEC. MO.02-6 MO.02-7 Eligibility Determination: Eligible MO.02-1 Radiological Survey(s): Assessment Surveys MO.02-2 MO.02-3 Site

  10. Mo-99 | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Mo-99 | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Countering Nuclear Terrorism About Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Library Bios Congressional Testimony Fact Sheets Newsletters Press Releases Photo Gallery Jobs Apply for Our Jobs Our Jobs Working at NNSA Blog Home /

  11. Local environment of Mn in Mn delta-doped Si layers

    SciTech Connect (OSTI)

    Xiao, Q.F.; Kahwaji, S.; Monchesky, T.L.; Gordon, R.A.; Crozier, E.D.

    2009-11-09

    Dilute magnetic semiconductors combine both magnetic ordering and semiconducting behaviour, leading to potential spintronic applications. Silicon containing dilute Mn impurities is a potential dilute magnetic semiconductor. We have grown Mn delta-doped films by deposition of 0.7 of a monolayer of Mn on Si(001) by molecular beam epitaxy and capping the film with Si. The magnetic properties are likely sensitive to the distribution of Mn on substitutional or interstitial sites and the formation of metallic precipitates. We have used polarization-dependent XAFS to examine the local structure. We compare to a thicker MnSi film grown on Si(111) and also examine the influence of lead on the manganese environment when used as a surfactant in the growth process.

  12. Properties of (Ga,Mn)As codoped with Li

    SciTech Connect (OSTI)

    Miyakozawa, Shohei; Chen, Lin; Matsukura, Fumihiro; Ohno, Hideo

    2014-06-02

    We grow Li codoped (Ga,Mn)As layers with nominal Mn composition up to 0.15 by molecular beam epitaxy. The layers before and after annealing are characterized by x-ray diffraction, transport, magnetization, and ferromagnetic resonance measurements. The codoping with Li reduces the lattice constant and electrical resistivity of (Ga,Mn)As after annealing. We find that (Ga,Mn)As:Li takes similar Curie temperature to that of (Ga,Mn)As, but with pronounced magnetic moments and in-plane magnetic anisotropy, indicating that the Li codoping has nontrivial effects on the magnetic properties of (Ga,Mn)As.

  13. A SUPER-EDDINGTON WIND SCENARIO FOR THE PROGENITORS OF TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Ma, Xin; Chen, Xuefei; Chen, Hai-liang; Han, Zhanwen; Denissenkov, Pavel A. E-mail: cxf@ynao.ac.cn

    2013-12-01

    The accretion of hydrogen-rich material on to carbon-oxygen white dwarfs (CO WDs) is crucial for understanding Type Ia supernova (SN Ia) from the single-degenerate model, but this process has not been well understood due to the numerical difficulties in treating H and He flashes during the accretion. For CO WD masses from 0.5 to 1.378 M {sub ?} and accretion rates in the range from 10{sup 8} to 10{sup 5} M {sub ?} yr{sup 1}, we simulated the accretion of solar-composition material on to CO WDs using the state-of-the-art stellar evolution code of MESA. For comparison with steady-state models, we first ignored the contribution from nuclear burning to the luminosity when determining the Eddington accretion rate, and found that the properties of H burning in our accreting CO WD models are similar to those from the steady-state models, except that the critical accretion rates at which the WDs turn into red giants or H-shell flashes occur on their surfaces are slightly higher than those from the steady-state models. However, the super-Eddington wind is triggered at much lower accretion rates than previously thought, when the contribution of nuclear burning to the total luminosity is included. This super-Eddington wind naturally prevents the CO WDs with high accretion rates from becoming red giants, thus presenting an alternative to the optically thick wind proposed by Hachisu etal. Furthermore, the super-Eddington wind works in low-metallicity environments, which may explain SNe Ia observed at high redshifts.

  14. DOE - Office of Legacy Management -- Rogers Iron Works Co - MO 10

    Office of Legacy Management (LM)

    Rogers Iron Works Co - MO 10 FUSRAP Considered Sites Site: ROGERS IRON WORKS CO. (MO.10 ) Elimination from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Rogers Iron Co. MO.10-1 Location: Joplin , Missouri MO.10-1 Evaluation Year: 1990 MO.10-2 MO.10-3 Site Operations: Tested C-liner crushing methods. MO.10-1 Site Disposition: Eliminated - Potential for contamination considered remote based on limited quantities of material handled MO.10-3 MO.10-4 Radioactive Materials

  15. IA REP0 SAND85-2809 Unlimited Release UC-92A

    Office of Scientific and Technical Information (OSTI)

    IA REP0 SAND85-2809 Unlimited Release UC-92A Printed July 1986 High Energy Gas Fracture Experiments in Fluid-Filled Boreholes-Potential Geothermal Application J. F. Cuderman, T. Y. Chu, J. Jung, R. D. Jacobson Prepared by Sandia National Laboratories Albuquerque, New Mexico 87 185 and Livermore, California 94550 for the United States Department of Energy under Contract DE-AC04-76DP00789 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States

  16. Demonstration of LED Street Lighting in Kansas City, MO Kinzey...

    Office of Scientific and Technical Information (OSTI)

    Street Lighting in Kansas City, MO Kinzey, Bruce R.; Royer, Michael P.; Hadjian, M.; Kauffman, Rick LED streetlighting; field illuminance measurement LED streetlighting; field...

  17. MoRu/Be multilayers for extreme ultraviolet applications

    DOE Patents [OSTI]

    Bajt, Sasa C. (Livermore, CA); Wall, Mark A. (Stockton, CA)

    2001-01-01

    High reflectance, low intrinsic roughness and low stress multilayer systems for extreme ultraviolet (EUV) lithography comprise amorphous layers MoRu and crystalline Be layers. Reflectance greater than 70% has been demonstrated for MoRu/Be multilayers with 50 bilayer pairs. Optical throughput of MoRu/Be multilayers can be 30-40% higher than that of Mo/Be multilayer coatings. The throughput can be improved using a diffusion barrier to make sharper interfaces. A capping layer on the top surface of the multilayer improves the long-term reflectance and EUV radiation stability of the multilayer by forming a very thin native oxide that is water resistant.

  18. Dynamic Structural Response and Deformations of Monolayer MoS...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Dynamic Structural Response and Deformations of Monolayer MoS 2 Visualized by Femtosecond Electron Diffraction Citation Details ...

  19. Valence and metal/silicate partitioning of Mo: Implications for...

    Office of Scientific and Technical Information (OSTI)

    Valence and metalsilicate partitioning of Mo: Implications for conditions of Earth accretion and core formation Citation Details In-Document Search Title: Valence and metal...

  20. Mo Year Report Period: EIA ID NUMBER:

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

    Mo Year Report Period: EIA ID NUMBER: http://www.eia.gov/survey/form/eia_14/instructions.pdf Mailing Address: Secure File Transfer option available at: (e.g., PO Box, RR) https://signon.eia.doe.gov/upload/noticeoog.jsp Electronic Transmission: The PC Electronic Zip Code - Data Reporting Option (PEDRO) is available. If interested in software, call (202) 586-9659. Email form to: OOG.SURVEYS@eia.doe.gov - - - - Fax form to: (202) 586-9772 Mail form to: Oil & Gas Survey Email address: U.S.

  1. Spin reorientation and Ce-Mn coupling in antiferromagnetic oxypnictide CeMnAsO

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

    Zhang, Qiang; Tian, Wei; Peterson, Spencer G.; Dennis, Kevin W.; Vaknin, David

    2015-02-18

    Structure and magnetic properties of high-quality polycrystlline CeMnAsO, a parent compound of the “1111”-type oxypnictides, have been investigated using neutron powder diffraction and magnetization measurements. We find that CeMnAsO undergoes a C-type antiferromagnetic order with Mn2+(S = 5/2) moments pointing along the c axis below a relatively high Néel temperature of TN = 347(1) K. Below TSR = 35 K, two simultaneous transitions occur where the Mn moments reorient from the c axis to the ab plane preserving the C-type magnetic order, and Ce moments undergo long-range AFM ordering with antiparallel moments pointing in the ab plane. Another transition tomore » a noncollinear magnetic structure occurs below 7 K. The ordered moments of Mn and Ce at 2 K are 3.32(4) μB and 0.81(4)μB, respectively. We find that CeMnAsO primarily falls into the category of a local-moment antiferromagnetic insulator in which the nearest-neighbor interaction (J1) is dominant with J2 < J1/2 in the context of J1 – J2 – Jc model. The spin reorientation transition driven by the coupling between Ce and the transition metal seems to be common to Mn, Fe, and Cr ions, but not to Co and Ni ions in the isostructural oxypnictides. As a result, a schematic illustration of magnetic structures in Mn and Ce sublattices in CeMnAsO is presented.« less

  2. Magnetoelectric coupling tuned by competing anisotropies in Mn...

    Office of Scientific and Technical Information (OSTI)

    Magnetoelectric coupling tuned by competing anisotropies in Mn 1 - x Ni x TiO 3 Prev Next Title: Magnetoelectric coupling tuned by competing anisotropies in Mn 1 - x Ni x TiO ...

  3. Structure and electronic properties of Cu nanoclusters supported on Mo2C(001) and MoC(001) surfaces

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

    Posada-Pérez, Sergio; Viñes, Francesc; Rodríguez, José A.; Illas, Francesc

    2015-09-15

    In this study, the atomic structure and electronic properties of Cun nanoclusters (n = 4, 6, 7, and 10) supported on cubic nonpolar δ-MoC(001) and orthorhombic C- or Mo-terminated polar β-Mo2C(001) surfaces have been investigated by means of periodic density functional theory based calculations. The electronic properties have been analyzed by means of the density of states, Bader charges, and electron localization function plots. The Cu nanoparticles supported on β-Mo2C(001), either Mo- or C-terminated, tend to present a two-dimensional structure whereas a three-dimensional geometry is preferred when supported on δ-MoC(001), indicating that the Mo:C ratio and the surface polarity playmore » a key role determining the structure of supported clusters. Nevertheless, calculations also reveal important differences between the C- and Mo-terminated β-Mo2C(001) supports to the point that supported Cu particles exhibit different charge states, which opens a way to control the reactivity of these potential catalysts.« less

  4. TYCHO SN 1572: A NAKED Ia SUPERNOVA REMNANT WITHOUT AN ASSOCIATED AMBIENT MOLECULAR CLOUD

    SciTech Connect (OSTI)

    Tian, W. W.; Leahy, D. A.

    2011-03-10

    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.

  5. Consistent use of type Ia supernovae highly magnified by galaxy clusters to constrain the cosmological parameters

    SciTech Connect (OSTI)

    Zitrin, Adi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Redlich, Matthias [Universitt Heidelberg, Zentrum fr Astronomie, Institut fr Theoretische Astrophysik, Philosophenweg 12, D-69120 Heidelberg (Germany); Broadhurst, Tom, E-mail: adizitrin@gmail.com [Department of Theoretical Physics, University of Basque Country UPV/EHU, Bilbao (Spain)

    2014-07-01

    We discuss how Type Ia supernovae (SNe) strongly magnified by foreground galaxy clusters should be self-consistently treated when used in samples fitted for the cosmological parameters. While the cluster lens magnification of a SN can be well constrained from sets of multiple images of various background galaxies with measured redshifts, its value is typically dependent on the fiducial set of cosmological parameters used to construct the mass model. In such cases, one should not naively demagnify the observed SN luminosity by the model magnification into the expected Hubble diagram, which would create a bias, but instead take into account the cosmological parameters a priori chosen to construct the mass model. We quantify the effect and find that a systematic error of typically a few percent, up to a few dozen percent per magnified SN may be propagated onto a cosmological parameter fit unless the cosmology assumed for the mass model is taken into account (the bias can be even larger if the SN is lying very near the critical curves). We also simulate how such a bias propagates onto the cosmological parameter fit using the Union2.1 sample supplemented with strongly magnified SNe. The resulting bias on the deduced cosmological parameters is generally at the few percent level, if only few biased SNe are included, and increases with the number of lensed SNe and their redshift. Samples containing magnified Type Ia SNe, e.g., from ongoing cluster surveys, should readily account for this possible bias.

  6. Spectroscopic Determination of the Low Redshift Type Ia Supernova Rate from the Sloan Digital Sky Survey

    SciTech Connect (OSTI)

    Krughoff, K. S.; Connolly, Andrew J.; Frieman, Joshua; SubbaRao, Mark; Kilper, Gary; Schneider, Donald P.

    2011-04-10

    Supernova rates are directly coupled to high mass stellar birth and evolution. As such, they are one of the few direct measures of the history of cosmic stellar evolution. In this paper we describe an probabilistic technique for identifying supernovae within spectroscopic samples of galaxies. We present a study of 52 type Ia supernovae ranging in age from -14 days to +40 days extracted from a parent sample of \\simeq 50,000 spectra from the SDSS DR5. We find a Supernova Rate (SNR) of 0.472^{+0.048}_{-0.039}(Systematic)^{+0.081}_{-0.071}(Statistical)SNu at a redshift of = 0.1. This value is higher than other values at low redshift at the 1{\\sigma}, but is consistent at the 3{\\sigma} level. The 52 supernova candidates used in this study comprise the third largest sample of supernovae used in a type Ia rate determination to date. In this paper we demonstrate the potential for the described approach for detecting supernovae in future spectroscopic surveys.

  7. Effect of Mn doping on structural and magnetic susceptibility of C-type rare earth nano oxides Er{sub 2?x}Mn{sub x}O{sub 3}

    SciTech Connect (OSTI)

    Heiba, Zein K.; Taif University, Faculty of Science, Physics Department ; Mohamed, Mohamed Bakr; Fuess, H.

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ? Er{sub 2?x}Mn{sub x}O{sub 3} (0.0 ? x ? 0.20) prepared by solgel method. ? The change in lattice parameter is not linear with x due to the change in crystallite size with doping. ? Anomalous concentration dependence is found in magnetic susceptibility. ? The effective magnetic moment ?{sub eff} is found to decrease with composition parameter x. ? Superexchange interactions between Er ions depending on the amount of Mn or Er in different sites. -- Abstract: The manganese doped rare earth oxides Er{sub 2?x}Mn{sub x} O{sub 3} (0.0 ? x ? 0.20) were synthesized by a solgel process and analyzed by X-ray diffraction using Rietveld refinement methods. A single phase solid solution is formed up to x = 0.15 while for x ? 0.2 a manganese oxide phase appears in the diffraction pattern. Preferential cationic distribution between the non-equivalent sites 8b and 24d of space group Ia3{sup } is found for all samples but to a different extent. The octahedral volume and average bond length of Er{sub 1}-O for 8b site decrease while both octahedral volume and bond length of Er{sub 2}-O for 24d site increase. Magnetization measurements were done in the temperature range 5300 K. The effective magnetic moment ?{sub eff} is found to decrease with composition parameter x, except for sample x = 0.05 where the magnetization is enhanced. The Curie-Weiss paramagnetic temperatures indicate antiferromagnetic interaction.

  8. DOE - Office of Legacy Management -- West Lake Landfill - MO 05

    Office of Legacy Management (LM)

    Lake Landfill - MO 05 FUSRAP Considered Sites Site: West Lake Landfill (MO.05) Designated Name: Alternate Name: Location: Evaluation Year: Site Operations: Site Disposition: Radioactive Materials Handled: Primary Radioactive Materials Handled: Radiological Survey(s): Site Status: Also see http://www.epa.gov/oerrpage/superfund/sites/npl/nar1289.htm Documents Related to West Lake Landfill

  9. CaMn2Al10: Itinerant Mn magnetism on the verge of magnetic order

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

    Steinke, L.; Simonson, J. W.; Yin, W. -G.; Smith, G. J.; Kistner-Morris, J. J.; Zellman, S.; Puri, A.; Aronson, M. C.

    2015-07-24

    We report the discovery of CaMn2Al10, a metal with strong magnetic anisotropy and moderate electronic correlations. Magnetization measurements find a Curie-Weiss moment of 0.83μB/Mn, significantly reduced from the Hund's rule value, and the magnetic entropy obtained from specific heat measurements is correspondingly small, only ≈ 9% of Rln2. These results imply that the Mn magnetism is highly itinerant, a conclusion supported by density functional theory calculations that find strong Mn-Al hybridization. Consistent with the layered nature of the crystal structure, the magnetic susceptibility χ is anisotropic below 20 K, with a maximum ratio of χ[010]/χ[001] ≈ 3.5. A strong power-lawmore » divergence χ(T) ~ T–1.2 below 20 K implies incipient ferromagnetic order, an Arrott plot analysis of the magnetization suggests a vanishing low Curie temperature TC ~ 0. Our experiments indicate that CaMn2Al10 is a rare example of a system where the weak and itinerant Mn-based magnetism is poised on the verge of order.« less

  10. Influence of interstitial Mn on magnetism in room-temperature ferromagnet Mn(1+delta)Sb

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

    Taylor, Alice E; Berlijn, Tom; Hahn, Steven E; May, Andrew F; Williams, Travis J; Poudel, Lekhanath N; Calder, Stuart A; Fishman, Randy Scott; Stone, Matthew B; Aczel, Adam A; et al

    2015-01-01

    We report elastic and inelastic neutron scattering measurements of the high-TC ferromagnet Mn(1+delta)Sb. Measurements were performed on a large, TC = 434 K, single crystal with interstitial Mn content of delta=0.13. The neutron diffraction results reveal that the interstitial Mn has a magnetic moment, and that it is aligned antiparallel to the main Mn moment. We perform density functional theory calculations including the interstitial Mn, and find the interstitial to be magnetic in agreement with the diffraction data. The inelastic neutron scattering measurements reveal two features in the magnetic dynamics: i) a spin-wave-like dispersion emanating from ferromagnetic Bragg positions (Hmore » K 2n), and ii) a broad, non-dispersive signal centered at forbidden Bragg positions (H K 2n+1). The inelastic spectrum cannot be modeled by simple linear spin-wave theory calculations, and appears to be significantly altered by the presence of the interstitial Mn ions. The results show that the influence of the int« less

  11. Influence of interstitial Mn on magnetism in room-temperature ferromagnet Mn(1+delta)Sb

    SciTech Connect (OSTI)

    Taylor, Alice E [ORNL; Berlijn, Tom [ORNL; Hahn, Steven E [ORNL; May, Andrew F [ORNL; Williams, Travis J [ORNL; Poudel, Lekhanath N [ORNL; Calder, Stuart A [ORNL; Fishman, Randy Scott [ORNL; Stone, Matthew B [ORNL; Aczel, Adam A [ORNL; Cao, Huibo [ORNL; Lumsden, Mark D [ORNL; Christianson, Andrew D [ORNL

    2015-01-01

    We report elastic and inelastic neutron scattering measurements of the high-TC ferromagnet Mn(1+delta)Sb. Measurements were performed on a large, TC = 434 K, single crystal with interstitial Mn content of delta=0.13. The neutron diffraction results reveal that the interstitial Mn has a magnetic moment, and that it is aligned antiparallel to the main Mn moment. We perform density functional theory calculations including the interstitial Mn, and find the interstitial to be magnetic in agreement with the diffraction data. The inelastic neutron scattering measurements reveal two features in the magnetic dynamics: i) a spin-wave-like dispersion emanating from ferromagnetic Bragg positions (H K 2n), and ii) a broad, non-dispersive signal centered at forbidden Bragg positions (H K 2n+1). The inelastic spectrum cannot be modeled by simple linear spin-wave theory calculations, and appears to be significantly altered by the presence of the interstitial Mn ions. The results show that the influence of the int

  12. Fragile structural transition in Mo3Sb7

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

    Yan, Jiaqiang -Q.; McGuire, Michael A; May, Andrew F; Parker, David S.; Mandrus, D. G.; Sales, Brian C.

    2015-08-10

    Mo3Sb7 single crystals lightly doped with Cr, Ru, or Te are studied in order to explore the interplay between superconductivity, magnetism, and the cubic-tetragonal structural transition. The structural transition at 53 K is extremely sensitive to Ru or Te substitution which introduces additional electrons, but robust against Cr substitution. We observed no sign of a structural transition in superconducting Mo2.91Ru0.09Sb7 and Mo3Sb6.975Te0.025. In contrast, 3 at.% Cr doping only slightly suppresses the structural transition to 48 K while leaving no trace of superconductivity above 1.8 K. Analysis of magnetic properties suggests that the interdimer interaction in Mo3Sb7 is near amorecritical value and essential for the structural transition. Futhermore, all dopants suppress the superconductivity of Mo3Sb7. The tetragonal structure is not necessary for superconductivity.less

  13. Neutrino scattering off the stable even-even Mo isotopes

    SciTech Connect (OSTI)

    Balasi, K. G.; Kosmas, T. S.; Divari, P. C. [Theoretical Physics Section, University of Ioannina, GR 45110 Ioannina (Greece)

    2009-11-09

    Inelastic neutrino-nucleus reaction cross sections are studied focusing on the neutral current processes. Particularly, we investigate the angular and initial neutrino-energy dependence of the differential and integrated cross sections for low and intermediate energies of the incoming neutrino. The nuclear wave functions for the initial and final nuclear states are constructed in the context of the quasi-particle random phase approximation (QRPA) tested on the reproducibility of the low-lying energy spectrum. The results presented here refer to the isotopes Mo{sup 92}, Mo{sup 94}, Mo{sup 96}, Mo{sup 98} and Mo{sup 100}. These isotopes could play a significant role in supernova neutrino detection in addition to their use in double-beta and neutrinoless double-beta decay experiments (e.g. MOON, NEMO III)

  14. DOE - Office of Legacy Management -- United Nuclear Corp - MO 0-03

    Office of Legacy Management (LM)

    Nuclear Corp - MO 0-03 FUSRAP Considered Sites Site: UNITED NUCLEAR CORP. (MO.0-03) Eliminated from further consideration under FUSRAP Designated Name: Not Designated Alternate Name: Mallinckrodt Chemical Works Mallinckrodt Nuclear Corporation MO.0-03-1 MO.0-03-2 Location: Hematite , Missouri MO.0-03-1 Evaluation Year: Circa 1987 MO.0-03-3 Site Operations: Commercial fuel fabrication operation. Licensed to reclaim unirradiated enriched uranium from scrap generated in fuel fabrication and fuel

  15. Opti-MN Impact House Presentation | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Opti-MN Impact House Presentation Opti-MN Impact House Presentation Opti-MN was the Grand Winner of the 2015 Race to Zero Student Design Competition. View the presentation for the Opti-MN Impact House below. Read a full list of the winning teams. PDF icon Opti-MN Presentation More Documents & Publications 2015 Race to Zero Competition Grand Winner and Grand Winner Finalist Team Submissions 2014 Race to Zero Student Design Competition: University of Minnesota Profile 2015 Race to Zero

  16. Two nucleon systems at mπ<mo>~>450mn>MeV from lattice QCD

    SciTech Connect (OSTI)

    Orginos, Kostas; Parreño, Assumpta; Savage, Martin J.; Beane, Silas R.; Chang, Emmanuel; Detmold, William

    2015-12-23

    Nucleon-nucleon systems are studied with lattice quantum chromodynamics at a pion mass of $m_\\pi\\sim 450~{\\rm MeV}$ in three spatial volumes using $n_f=2+1$ flavors of light quarks. At the quark masses employed in this work, the deuteron binding energy is calculated to be $B_d = 14.4^{+3.2}_{-2.6} ~{\\rm MeV}$, while the dineutron is bound by $B_{nn} = 12.5^{+3.0}_{-5.0}~{\\rm MeV}$. Over the range of energies that are studied, the S-wave scattering phase shifts calculated in the 1S0 and 3S1-3D1 channels are found to be similar to those in nature, and indicate repulsive short-range components of the interactions, consistent with phenomenological nucleon-nucleon interactions. In both channels, the phase shifts are determined at three energies that lie within the radius of convergence of the effective range expansion, allowing for constraints to be placed on the inverse scattering lengths and effective ranges. Thus, the extracted phase shifts allow for matching to nuclear effective field theories, from which low energy counterterms are extracted and issues of convergence are investigated. As part of the analysis, a detailed investigation of the single hadron sector is performed, enabling a precise determination of the violation of the Gell-Mann–Okubo mass relation.

  17. DOE - Office of Legacy Management -- Spencer Chemical Co - MO 0-01

    Office of Legacy Management (LM)

    MO 0-01 FUSRAP Considered Sites Site: SPENCER CHEMICAL CO. (MO.0-01) Eliminated from further consideration under FUSRAP - an AEC licensed operation Designated Name: Not Designated Alternate Name: Jayhawk Works MO.0-01-1 Location: Joplin , Missouri MO.0-01-1 Evaluation Year: 1985 MO.0-01-2 Site Operations: Processed enriched uranium (UF-6) and scrap to produce primarily uranium dioxide (UO-2) under AEC licenses. MO.0-01-3 MO.0-01-4 Site Disposition: Eliminated - No Authority MO.0-01-2 Radioactive

  18. DOE - Office of Legacy Management -- Tyson Valley Powder Farm - MO 11

    Office of Legacy Management (LM)

    Tyson Valley Powder Farm - MO 11 FUSRAP Considered Sites Site: TYSON VALLEY POWDER FARM (MO.11) Eliminated from further consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: St. Louis County , Missouri MO.11-1 Evaluation Year: 1987 MO.11-2 Site Operations: Storage of C-Special material (residue from production of uranium metal). MO.11-1 MO.11-2 MO.11-3 Site Disposition: Eliminated - Referred to Army Corps of Engineers MO.11-2 Radioactive Materials Handled: Yes

  19. Mo-O bond doping and related-defect assisted enhancement of photoluminescence in monolayer MoS{sub 2}

    SciTech Connect (OSTI)

    Wei, Xiaoxu; Yu, Zhihao; Cheng, Ying; Yu, Linwei; Wang, Junzhuan Wang, Xinran; Shi, Yi; Hu, Fengrui; Wang, Xiaoyong; Xiao, Min

    2014-12-15

    In this work, we report a strong photoluminescence (PL) enhancement of monolayer MoS{sub 2} under different treatments. We find that by simple ambient annealing treatment in the range of 200?C to 400?C, the PL emission can be greatly enhanced by a factor up to two orders of magnitude. This enhancement can be attributed to two factors: first, the formation of Mo-O bonds during ambient exposure introduces an effective p-doping in the MoS{sub 2} layer; second, localized electrons formed around Mo-O bonds related defective sites where the electrons can be effectively localized with higher binding energy resulting in efficient radiative excitons recombination. Time resolved PL decay measurement showed that longer lifetime of the treated sample consistent with the higher quantum efficiency in PL. These results give more insights to understand the luminescence properties of the MoS{sub 2}.

  20. Unexpected crystal and magnetic structures in MnCu4In and MnCu4Sn

    SciTech Connect (OSTI)

    Provino, A.; Paudyal, D.; Fornasini, ML; Dhiman, I.; Dhar, SK.; Das, A.; Mudryk, Y.; Manfrinetti, P.; Pecharsky, VK

    2013-01-29

    We discovered a new compound MnCu4In with its own hexagonal structure type (hP12-P63mc, ternary ordered derivative of the hexagonal MgZn2-type) that becomes ferromagnetic at TC = 540 K. This transition temperature is higher than that found in the MnCu2In and MnCu2Sn alloys. In contrast, the homologous compound MnCu4Sn, which crystallizes in the cubic MgCu4Sn-type, orders antiferromagnetically with TN = 110 K. The neutron diffraction studies show ferromagnetic spin orientation in the {1 0 1} plane in MnCu4In with a magnetic moment of 4.5 ?B/Mn at 22 K, and a corresponding value of 4.7 ?B/Mn in the antiferromagnetic MnCu4Sn with propagation vector View the MathML source. The first-principles electronic structure calculations show that the unexpected difference in both magnetic and crystal structures of MnCu4In and MnCu4Sn is due to the difference in the Mn-3d bands and exchange interactions relating to different crystal anisotropy, coordination numbers, and interatomic distances.

  1. Near-infrared line identification in type Ia supernovae during the transitional phase

    SciTech Connect (OSTI)

    Friesen, Brian; Baron, E.; Wisniewski, John P.; Miller, Timothy R. [Homer L. Dodge Department of Physics and Astronomy, 440 West Brooks Street, Room 100, Norman, OK 73019 (United States); Parrent, Jerod T. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Thomas, R. C. [Computational Cosmology Center, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, CA 94720 (United States); Marion, G. H. [University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States)

    2014-09-10

    We present near-infrared synthetic spectra of a delayed-detonation hydrodynamical model and compare them to observed spectra of four normal Type Ia supernovae ranging from day +56.5 to day +85. This is the epoch during which supernovae are believed to be undergoing the transition from the photospheric phase, where spectra are characterized by line scattering above an optically thick photosphere, to the nebular phase, where spectra consist of optically thin emission from forbidden lines. We find that most spectral features in the near-infrared can be accounted for by permitted lines of Fe II and Co II. In addition, we find that [Ni II] fits the emission feature near 1.98 ?m, suggesting that a substantial mass of {sup 58}Ni exists near the center of the ejecta in these objects, arising from nuclear burning at high density.

  2. LAX XXlCfl jX?iK, Idd+?KYLViG?IA

    Office of Legacy Management (LM)

    f , : I~&l, samtier cipwati8Aa CffUm - . Jiux.lCJ d,# 1754 - - _- - .- t :; . Jesse e. ahizmn*~*ter -2.' -------- - _ &tV' hi@A l f izau Bkteriala ;' . . 1 -7 I _' i' . Fpr&G& r&Q Q,&& fu &fI& L;&& -l&d 2;,i' iI,;/Qi' rIGN CQ&GgJy p;E& p;~p>gyf LAX XXlCfl jX?iK, Idd+?KYLViG?IA i-icfer~~o is &o ta yaw rwarandu3;: l P iimwmbec L?, 1953, reque&in~ a d&q.&ti of khority tA A&sister prog= for th+zz developmrrrl,

  3. Observation of D<mn>0mn> meson nuclear modifications in Au<mo>+>Au collisions at sNN<mo>=>200mn> GeV

    SciTech Connect (OSTI)

    Adamczyk, L.; Adkins, J.?K.; Agakishiev, G.; Aggarwal, M.?M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C.?D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E.?C.; Averichev, G.?S.; Banerjee, A.; Beavis, D.?R.; Bellwied, R.; Bhasin, A.; Bhati, A.?K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L.?C.; Bordyuzhin, I.?G.; Borowski, W.; Bouchet, J.; Brandin, A.?V.; Brovko, S.?G.; Bltmann, S.; Bunzarov, I.; Burton, T.?P.; Butterworth, J.; Caines, H.; Caldern de la Barca Snchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M.?C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H.?F.; Chen, J.?H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M.?J.?M.; Contin, G.; Cramer, J.?G.; Crawford, H.?J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L.?C.; Debbe, R.?R.; Dedovich, T.?G.; Deng, J.; Derevschikov, A.?A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J.?L.; Draper, J.?E.; Du, C.?M.; Dunkelberger, L.?E.; Dunlop, J.?C.; Efimov, L.?G.; Engelage, J.; Engle, K.?S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C.?E.; Gagliardi, C.?A.; Gangadharan, D.?R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D.?S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J.?W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G.?W.; Hofman, D.?J.; Horvat, S.; Huang, B.; Huang, H.?Z.; Huang, X.; Huck, P.; Humanic, T.?J.; Igo, G.; Jacobs, W.?W.; Jang, H.; Judd, E.?G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H.?W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z.?H.; Kikola, D.?P.; Kisel, I.; Kisiel, A.; Koetke, D.?D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A.?F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R.?A.; Lamont, M.?A.?C.; Landgraf, J.?M.; Landry, K.?D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J.?H.; LeVine, M.?J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z.?M.; Lisa, M.?A.; Liu, F.; Ljubicic, T.; Llope, W.?J.; Lomnitz, M.; Longacre, R.?S.; Luo, X.; Ma, G.?L.; Ma, Y.?G.; Madagodagettige Don, D.?M.?M.?D.; Mahapatra, D.?P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H.?S.; McDonald, D.; McShane, T.?S.; Minaev, N.?G.; Mioduszewski, S.; Mohanty, B.; Mondal, M.?M.; Morozov, D.?A.; Mustafa, M.?K.; Nandi, B.?K.; Nasim, Md.; Nayak, T.?K.; Nelson, J.?M.; Nigmatkulov, G.; Nogach, L.?V.; Noh, S.?Y.; Novak, J.; Nurushev, S.?B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E.?W.; Olvitt, D.?L.; Pachr, M.; Page, B.?S.; Pal, S.?K.; Pan, Y.?X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A.?M.; Pruthi, N.?K.; Przybycien, M.; Pujahari, P.?R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R.?L.; Riley, C.?K.; Ritter, H.?G.; Roberts, J.?B.; Rogachevskiy, O.?V.; Romero, J.?L.; Ross, J.?F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N.?R.; Sahu, P.?K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R.?P.; Schmah, A.?M.; Schmidke, W.?B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P.?V.; Shao, M.; Sharma, B.; Shen, W.?Q.; Shi, S.?S.; Shou, Q.?Y.; Sichtermann, E.?P.; Singaraju, R.?N.; Skoby, M.?J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H.?M.; Srivastava, B.; Stanislaus, T.?D.?S.; Stevens, J.?R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X.?M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D.?N.; Symons, T.?J.?M.; Szelezniak, M.?A.; Takahashi, J.; Tang, A.?H.; Tang, Z.; Tarnowsky, T.; Thomas, J.?H.; Timmins, A.?R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R.?E.; Tribedy, P.; Trzeciak, B.?A.; Tsai, O.?D.; Turnau, J.; Ullrich, T.; Underwood, D.?G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J.?A.; Varma, R.; Vasconcelos, G.?M.?S.; Vasiliev, A.?N.; Vertesi, R.; Videbk, F.; Viyogi, Y.?P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J.?S.; Wang, X.?L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J.?C.; Westfall, G.?D.; Wieman, H.; Wissink, S.?W.; Witt, R.; Wu, Y.?F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.

    2014-09-30

    We report the first measurement of charmed-hadron (D0) production via the hadronic decay channel (D0?K-+?+) in Au+Au collisions at ?sNN=200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, Nbin, from p+p to central Au+Au collisions. The D0 meson yields in central Au+Aucollisions are strongly suppressed compared to those in p+p scaled by Nbin, for transverse momenta pT>3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate pT is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

  4. Materials Data on Mn3Mo2H34C22N16O5 (SG:15) by Materials Project

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

    Kristin Persson

    2015-05-17

    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

  5. Materials Data on Mn3Mo2H34C22N16O5 (SG:15) 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. Levels in N<mn>12mn> via the N<mn>14mn> (p<mo>,>t) reaction using the JENSA gas-jet target

    SciTech Connect (OSTI)

    Chipps, K. A.; Pain, S. D.; Greife, U.; Kozub, R. L.; Bardayan, D. W.; Blackmon, J. C.; Kontos, A.; Linhardt, L. E.; Matos, M.; Pittman, S. T.; Sachs, A.; Schatz, H.; Schmitt, K. T.; Smith, M. S.; Thompson, P.

    2015-09-25

    As one of a series of physics cases to demonstrate the unique benefit of the new Jet Experiments in Nuclear Structure and Astrophysics gas-jet target for enabling next-generation transfer reaction studies, the ?N (p, t)N reaction was studied for the first time, using a pure jet of nitrogen, in an attempt to resolve conflicting information on the structure of N. A new level at 4.561-MeV excitation energy in N was found.

  7. EARLY OBSERVATIONS AND ANALYSIS OF THE TYPE Ia SN 2014J IN M82

    SciTech Connect (OSTI)

    Marion, G. H.; Vink, J. [University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); Sand, D. J. [Physics Department, Texas Tech University, Lubbock, TX 79409 (United States); Hsiao, E. Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Banerjee, D. P. K.; Joshi, V.; Venkataraman, V.; Ashok, N. M. [Astronomy and Astrophysics Division, Physical Research Laboratory, Navrangapura, Ahmedabad - 380009, Gujarat (India); Valenti, S.; Howell, D. A. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Stritzinger, M. D. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Amanullah, R.; Johansson, J. [The Oskar Klein Centre, Physics Department, Stockholm University, Albanova University Center, SE 106 91 Stockholm (Sweden); Binzel, R. P. [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Bochanski, J. J. [Haverford College, 370 Lancaster Avenue, Haverford, PA 19041 (United States); Bryngelson, G. L. [Department of Physics and Astronomy, Francis Marion University, 4822 East Palmetto Street, Florence, SC 29506 (United States); Burns, C. R. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Drozdov, D. [Department of Physics and Astronomy, Clemson University, 8304 University Station, Clemson, SC 29634 (United States); Fieber-Beyer, S. K. [Department of Space Studies, University of North Dakota, University Stop 9008, ND 58202 (United States); Graham, M. L., E-mail: hman@astro.as.utexas.edu [Astronomy Department, University of California at Berkeley, Berkeley, CA 94720 (United States); and others

    2015-01-01

    We present optical and near infrared (NIR) observations of the nearby Type Ia SN 2014J. Seventeen optical and 23 NIR spectra were obtained from 10days before (10d) to 10days after (+10d) the time of maximum B-band brightness. The relative strengths of absorption features and their patterns of development can be compared at one day intervals throughout most of this period. Carbon is not detected in the optical spectra, but we identify C I?1.0693 in the NIR spectra. Mg II lines with high oscillator strengths have higher initial velocities than other Mg II lines. We show that the velocity differences can be explained by differences in optical depths due to oscillator strengths. The spectra of SN 2014J show that it is a normal SN Ia, but many parameters are near the boundaries between normal and high-velocity subclasses. The velocities for O I, Mg II, Si II, S II, Ca II, and Fe II suggest that SN 2014J has a layered structure with little or no mixing. That result is consistent with the delayed detonation explosion models. We also report photometric observations, obtained from 10d to +29d, in the UBVRIJH and K{sub s} bands. The template fitting package SNooPy is used to interpret the light curves and to derive photometric parameters. Using R{sub V} = 1.46, which is consistent with previous studies, SNooPy finds that A{sub V} = 1.80 for E(B V){sub host} = 1.23 0.06 mag. The maximum B-band brightness of 19.19 0.10 mag was reached on February 1.74 UT 0.13days and the supernova has a decline parameter, ?m {sub 15}, of 1.12 0.02 mag.

  8. U.S. Energy Information Administration | Annual Energy Outlook...

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    OH 1. NE 3. S1 4. S2 5. GF 6. OH 7. EN AL,MS MN,ND,SD IA,NE,MO,KS TX,LA,OK,AR MT,WY,ID CO,UT,NV AZ,NM 9. AM 11. C2 12. WS 13. MT 14. CU 15. ZN WV,MD,DC,DE 2. YP...

  9. Polystyrene/MoS{sub 2}@oleylamine nanocomposites

    SciTech Connect (OSTI)

    Altavilla, Claudia; Ciambelli, Paolo; Fedi, Filippo; Sorrentino, Andrea; Iannace, Salvatore

    2014-05-15

    The effects of adding different concentrations of MoS{sub 2}@oleylamine nano particles on the thermal and mechanical properties of polystyrene (PS) nanocomposites have been investigated. X-ray diffraction and optical microscopy were used to characterize the morphology of the resulting nanocomposites. The thermal stability of the nanocomposites has been characterized by thermogravimetric analysis. It has been found that the MoS{sub 2}@oleylamine nanoparticles have a good compatibility with the PS matrix forming homogeneous dispersion even at high concentrations. The PS/MoS{sub 2}@oleylamine nanocomposites showed enhanced thermal stability in comparison with neat polystyrene.

  10. EVOLUTION OF POST-IMPACT REMNANT HELIUM STARS IN TYPE Ia SUPERNOVA REMNANTS WITHIN THE SINGLE-DEGENERATE SCENARIO

    SciTech Connect (OSTI)

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E. E-mail: pmricker@illinois.edu

    2013-08-10

    The progenitor systems of Type Ia supernovae (SNe Ia) are still under debate. Based on recent hydrodynamics simulations, non-degenerate companions in the single-degenerate scenario (SDS) should survive the supernova (SN) impact. One way to distinguish between the SDS and the double-degenerate scenario is to search for the post-impact remnant stars (PIRSs) in SN Ia remnants. Using a technique that combines multi-dimensional hydrodynamics simulations with one-dimensional stellar evolution simulations, we have examined the post-impact evolution of helium-rich binary companions in the SDS. It is found that these helium-rich PIRSs (He PIRSs) dramatically expand and evolve to a luminous phase (L {approx} 10{sup 4} L{sub Sun }) about 10 yr after an SN explosion. Subsequently, they contract and evolve to become hot blue-subdwarf-like (sdO-like) stars by releasing gravitational energy, persisting as sdO-like stars for several million years before evolving to the helium red-giant phase. We therefore predict that a luminous OB-like star should be detectable within {approx}30 yr after the SN explosion. Thereafter, it will shrink and become an sdO-like star in the central regions of SN Ia remnants within star-forming regions for SN Ia progenitors evolved via the helium-star channel in the SDS. These He PIRSs are predicted to be rapidly rotating (v{sub rot} {approx}> 50 km s{sup -1}) and to have high spatial velocities (v{sub linear} {approx}> 500 km s{sup -1}). Furthermore, if SN remnants have diffused away and are not recognizable at a later stage, He PIRSs could be an additional source of single sdO stars and/or hypervelocity stars.

  11. Measurements of the Rate of Type Ia Supernovae at Redshift z < ~0.3 from the SDSS-II Supernova Survey

    SciTech Connect (OSTI)

    Dilday, Benjamin; Smith, Mathew; Bassett, Bruce; Becker, Andrew; Bender, Ralf; Castander, Francisco; Cinabro, David; Filippenko, Alexei V.; Frieman, Joshua A.; Galbany, Lluis; Garnavich, Peter M.; /Notre Dame U. /Stockholm U., OKC /Stockholm U.

    2010-01-01

    We present a measurement of the volumetric Type Ia supernova (SN Ia) rate based on data from the Sloan Digital Sky Survey II (SDSS-II) Supernova Survey. The adopted sample of supernovae (SNe) includes 516 SNe Ia at redshift z {approx}< 0.3, of which 270 (52%) are spectroscopically identified as SNe Ia. The remaining 246 SNe Ia were identified through their light curves; 113 of these objects have spectroscopic redshifts from spectra of their host galaxy, and 133 have photometric redshifts estimated from the SN light curves. Based on consideration of 87 spectroscopically confirmed non-Ia SNe discovered by the SDSS-II SN Survey, we estimate that 2.04{sub -0.95}{sup +1.61}% of the photometric SNe Ia may be misidentified. The sample of SNe Ia used in this measurement represents an order of magnitude increase in the statistics for SN Ia rate measurements in the redshift range covered by the SDSS-II Supernova Survey. If we assume a SN Ia rate that is constant at low redshift (z < 0.15), then the SN observations can be used to infer a value of the SN rate of r{sub V} = (2.69{sub -0.30-0.01}{sup +0.34+0.21}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} at a mean redshift of {approx} 0.12, based on 79 SNe Ia of which 72 are spectroscopically confirmed. However, the large sample of SNe Ia included in this study allows us to place constraints on the redshift dependence of the SN Ia rate based on the SDSS-II Supernova Survey data alone. Fitting a power-law model of the SN rate evolution, r{sub V} (z) = A{sub p} x ((1+z)/(1+z{sub 0})){sup {nu}}, over the redshift range 0.0 < z < 0.3 with z{sub 0} = 0.21, results in A{sub p} = (3.43{sub -0.15}{sup +0.15}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} and {nu} = 2.04{sub -0.89}{sup +0.90}.

  12. 9 Cr-- 1 Mo steel material for high temperature application

    DOE Patents [OSTI]

    Jablonski, Paul D; Alman, David; Dogan, Omer; Holcomb, Gordon; Cowen, Christopher

    2012-11-27

    One or more embodiments relates to a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650.degree. C. The 9 Cr-1 Mo steel has a tempered martensite microstructure and is comprised of both large (0.5-3 .mu.m) primary titanium carbides and small (5-50 nm) secondary titanium carbides in a ratio of. from about 1:1.5 to about 1.5:1. The 9 Cr-1 Mo steel may be fabricated using exemplary austenizing, rapid cooling, and tempering steps without subsequent hot working requirements. The 9 Cr-1 Mo steel exhibits improvements in total mass gain, yield strength, and time-to-rupture over ASTM P91 and ASTM P92 at the temperature and time conditions examined.

  13. Support effects on hydrotreating activity of NiMo catalysts

    SciTech Connect (OSTI)

    Dominguez-Crespo, M.A. Arce-Estrada, E.M.; Torres-Huerta, A.M.

    2007-10-15

    The effect of the gamma alumina particle size on the catalytic activity of NiMoS{sub x} catalysts prepared by precipitation method of aluminum acetate at pH = 10 was studied. The structural characterization of the supports was measured by using XRD, pyridine FTIR-TPD and nitrogen physisorption. NiMo catalysts were characterized during the preparation steps (annealing and sulfidation) using transmission electron microscopy (TEM). Hydrogen TPR studies of the NiMo catalysts were also carried out in order to correlate their hydrogenating properties and their catalytic functionality. Catalytic tests were carried out in a pilot plant at 613, 633 and 653 K temperatures. The results showed that the rate constants of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatizing (HDA) at 613-653 K decreased in the following order: A > B > C corresponding to the increase of NiMoS particle size associated to these catalysts.

  14. CO2ReMoVe | Open Energy Information

    Open Energy Info (EERE)

    of industrial, research and service organizations with experience in CO2 geological storage. References: CO2ReMoVe1 This article is a stub. You can help OpenEI by expanding...

  15. Structural Insights into FeMo Cofactor Biosynthesis

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

    a catalytic component and a specific reductase, which, in the standard system, are referred to as the MoFe protein and the Fe protein. At the active site of the...

  16. Co-Mo Electric Cooperative- Energy Efficiency Rebate Program

    Broader source: Energy.gov [DOE]

    Co-Mo Electric Cooperative provides rebates to its residential and commercial members who install air source, dual fuel, and/or geothermal heat pumps, and certain energy efficient appliances. Heat...

  17. M.O. Wascko, LSU NuInt05...

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

    O. Wascko, LSU NuInt05 26 September, 2005 MiniBooNE CC + CCQE Ratio M.O. Wascko, LSU J.R. Monroe, Columbia CC interactions Quasi-Elastic (CCQE) Inclusive Single +...

  18. Ethanol Conversion on Cyclic (MO3)3 (M = Mo, W) Clusters

    SciTech Connect (OSTI)

    Li, Zhenjun; Fang, Zongtang; Kelley, Matthew S.; Kay, Bruce D.; Rousseau, Roger J.; Dohnalek, Zdenek; Dixon, David A.

    2014-03-06

    Oxides of molybdenum and tungsten are an important class of catalytic materials with applications ranging from isomerization of alkanes and alkenes, partial oxidation of alcohols, selective reduction of nitric oxide and metathesis of alkeness.[1-10] While many studies have focused on the structure - function relationships, the nature of high catalytic activity is still being extensively investigated. There is a general agreement that the activity of supported MOx (M = W, Mo) catalysts is correlated with the presence of acidic sites, where the catalytic activity is strongly affected by the type of oxide support, delocalization of electron density, structures of tungsten oxide domains and presence of protons

  19. Microstructures in rapidly solidified Ni-Mo alloys

    SciTech Connect (OSTI)

    Jayaraman, N.; Tewari, S.N.; Hemker, K.J.; Glasgow, T.K.

    1985-01-01

    Ni-Mo alloys of compositions ranging from pure Ni to Ni-40 at % Mo were rapidly solidified by chill block melt spinning in vacuum and were examined by optical metallography, x-ray diffraction and transmission electron microscopy. Rapid solidification resulted in an extension of molybdenum solubility in nickel from 28 to 37.5 at %. A number of different phases and microstructures were seen at different depths (solidification conditions) from the quenched surface of the melt spun ribbons.

  20. DOE - Office of Legacy Management -- Medart Co - MO 09

    Office of Legacy Management (LM)

    Medart Co - MO 09 FUSRAP Considered Sites Site: MEDART CO. (MO.09 ) Eliminated from consideration under FUSRAP - Facility believed to be torn down and the original site built over Designated Name: Not Designated Alternate Name: None Location: 180 Potomoc Street , St. Louis , Missouri MA.09-4 Evaluation Year: Circa 1990 MA.09-3 Site Operations: Conducted test machining operations on uranium bar stock during the early 1950s. MA.09-2 Site Disposition: Eliminated - Potential for contamination

  1. GUT-inspired supersymmetric model for h <mo stretchy="false">?mo> ? ? and the muon g <mo>-> <mn>2mn>

    SciTech Connect (OSTI)

    Ajaib, M. Adeel; Gogoladze, Ilia; Shafi, Qaisar

    2015-05-06

    We study a grand unified theories inspired supersymmetric model with nonuniversal gaugino masses that can explain the observed muon g-2 anomaly while simultaneously accommodating an enhancement or suppression in the h??? decay channel. In order to accommodate these observations and mh?125 to 126 GeV, the model requires a spectrum consisting of relatively light sleptons whereas the colored sparticles are heavy. The predicted stau mass range corresponding to R???1.1 is 100 GeV?m??200 GeV. The constraint on the slepton masses, particularly on the smuons, arising from considerations of muon g-2 is somewhat milder. The slepton masses in this case are predicted to lie in the few hundred GeV range. The colored sparticles turn out to be considerably heavier with mg?4.5 TeV and mt??3.5 TeV, which makes it challenging for these to be observed at the 14 TeV LHC.

  2. Magnetic properties of ??MnO{sub 2} and Co-doped ??MnO{sub 2} nanowires

    SciTech Connect (OSTI)

    Stella, C. Soundararajan, N. Ramachandran, K.

    2014-04-24

    ??MnO{sub 2} and Co-doped ??MnO{sub 2} nanowires (NWs) were synthesized by hydrothermal method. The structural characterization by XRD revealed the tetragonal structure of ??MnO{sub 2}. The formation of one dimensional (1D) NWs of pure and Co-doped ??MnO{sub 2} was confirmed from SEM. From UV-Vis absorption spectra, it is found that both pure and Co-doped ??MnO{sub 2} NWs showed blue shift compared to bulk, which revealed the quantum confinement in the synthesized samples. The magnetic properties were analyzed by VSM, which suggest that pure and doped ??MnO{sub 2} exhibit ferromagnetic behavior at room temperature (RT)

  3. DOE - Office of Legacy Management -- St Louis University - MO 0-02

    Office of Legacy Management (LM)

    University - MO 0-02 FUSRAP Considered Sites Site: ST. LOUIS UNIVERSITY (MO.0-02) Eliminated from consideration under FUSRAP - As of 1987 the facility operated under an NRC license Designated Name: Not Designated Alternate Name: None Location: St. Louis , Missouri MO.0-02-1 Evaluation Year: 1987 MO.0-02-1 Site Operations: Performed research activities involving small quantities of radioactive materials in a controlled environment. MO.0-02-1 Site Disposition: Eliminated - No Authority - Potential

  4. Spin caloritronics in graphene with Mn

    SciTech Connect (OSTI)

    Torres, Alberto Lima, Matheus P. Fazzio, A.; Silva, Antnio J. R. da

    2014-02-17

    We show that graphene with Mn adatoms trapped at single vacancies features spin-dependent Seebeck effect, thus enabling the use of this material for spin caloritronics. A gate potential can be used to tune its thermoelectric properties in a way it presents either a total spin polarized current, flowing in one given direction, or currents for both spins flowing in opposite directions without net charge transport. Moreover, we show that the thermal magnetoresistance can be tuned between ?100% and +100% by varying a gate potential.

  5. A Measurement of the Rate of Type Ia Supernovae in Galaxy Clusters from the SDSS-II Supernova Survey

    SciTech Connect (OSTI)

    Dilday, Benjamin; Bassett, Bruce; Becker, Andrew; Bender, Ralf; Castander, Francisco; Cinabro, David; Frieman, Joshua A.; Galbany, Lluis; Garnavich, Peter; Goobar, Ariel; Hopp, Ulrich; /Munich, Tech. U. /Munich U. Observ. /Tokyo U.

    2010-03-01

    We present measurements of the Type Ia supernova (SN) rate in galaxy clusters based on data from the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. The cluster SN Ia rate is determined from 9 SN events in a set of 71 C4 clusters at z {le} 0.17 and 27 SN events in 492 maxBCG clusters at 0.1 {le} z {le} 0.3. We find values for the cluster SN Ia rate of (0.37{sub -0.12-0.01}{sup +0.17+0.01}) SNur h{sup 2} and (0.55{sub -0.11-0.01}{sup +0.13+0.02}) SNur h{sup 2} (SNux = 10{sup -12}L{sub x{circle_dot}}{sup -1} yr{sup -1}) in C4 and maxBCG clusters, respectively, where the quoted errors are statistical and systematic, respectively. The SN rate for early-type galaxies is found to be (0.31{sub -0.12-0.01}{sup +0.18+0.01}) SNur h{sup 2} and (0.49{sub -0.11-0.01}{sup +0.15+0.02}) SNur h{sup 2} in C4 and maxBCG clusters, respectively. The SN rate for the brightest cluster galaxies (BCG) is found to be (2.04{sub -1.11-0.04}{sup +1.99+0.07}) SNur h{sup 2} and (0.36{sub -0.30-0.01}{sup +0.84+0.01}) SNur h{sup 2} in C4 and maxBCG clusters, respectively. The ratio of the SN Ia rate in cluster early-type galaxies to that of the SN Ia rate in field early-type galaxies is 1.94{sub -0.91-0.015}{sup +1.31+0.043} and 3.02{sub -1.03-0.048}{sup +1.31+0.062}, for C4 and maxBCG clusters, respectively. The SN rate in galaxy clusters as a function of redshift, which probes the late time SN Ia delay distribution, shows only weak dependence on redshift. Combining our current measurements with previous measurements, we fit the cluster SN Ia rate data to a linear function of redshift, and find r{sub L} = [(0.49{sub -0.14}{sup +0.15}) + (0.91{sub -0.81}{sup +0.85}) x z] SNuB h{sup 2}. A comparison of the radial distribution of SNe in cluster to field early-type galaxies shows possible evidence for an enhancement of the SN rate in the cores of cluster early-type galaxies. With an observation of at most 3 hostless, intra-cluster SNe Ia, we estimate the fraction of cluster SNe that are hostless to be (9.4{sub -5.1}{sup +8.3})%.

  6. Coated U(Mo) Fuel: As-Fabricated Microstructures

    SciTech Connect (OSTI)

    Emmanuel Perez; Dennis D. Keiser, Jr.; Ann Leenaers; Sven Van den Berghe; Tom Wiencek

    2014-04-01

    As part of the development of low-enriched uranium fuels, fuel plates have recently been tested in the BR-2 reactor as part of the SELENIUM experiment. These fuel plates contained fuel particles with either Si or ZrN thin film coating (up to 1 m thickness) around the U-7Mo fuel particles. In order to best understand irradiation performance, it is important to determine the starting microstructure that can be observed in as-fabricated fuel plates. To this end, detailed microstructural characterization was performed on ZrN and Si-coated U-7Mo powder in samples taken from AA6061-clad fuel plates fabricated at 500C. Of interest was the condition of the thin film coatings after fabrication at a relatively high temperature. Both scanning electron microscopy and transmission electron microscopy were employed. The ZrN thin film coating was observed to consist of columns comprised of very fine ZrN grains. Relatively large amounts of porosity could be found in some areas of the thin film, along with an enrichment of oxygen around each of the the ZrN columns. In the case of the pure Si thin film coating sample, a (U,Mo,Al,Si) interaction layer was observed around the U-7Mo particles. Apparently, the Si reacted with the U-7Mo and Al matrix during fuel plate fabrication at 500C to form this layer. The microstructure of the formed layer is very similar to those that form in U-7Mo versus Al-Si alloy diffusion couples annealed at higher temperatures and as-fabricated U-7Mo dispersion fuel plates with Al-Si alloy matrix fabricated at 500C.

  7. Unoccupied electronic structure of Ni2MnGa ferromagnetic shape...

    Office of Scientific and Technical Information (OSTI)

    Additional Journal Information: Journal Volume: 222; Journal Issue: C; Journal ID: ISSN 0038-1098 Publisher: Elsevier Research Org: Ames Laboratory (AMES), Ames, IA (United States) ...

  8. A POSSIBLE EVOLUTIONARY SCENARIO OF HIGHLY MAGNETIZED SUPER-CHANDRASEKHAR WHITE DWARFS: PROGENITORS OF PECULIAR TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Das, Upasana; Mukhopadhyay, Banibrata; Rao, A. R. E-mail: bm@physics.iisc.ernet.in

    2013-04-10

    Several recently discovered peculiar Type Ia supernovae seem to demand an altogether new formation theory that might help explain the puzzling dissimilarities between them and the standard Type Ia supernovae. The most striking aspect of the observational analysis is the necessity of invoking super-Chandrasekhar white dwarfs having masses {approx}2.1-2.8 M{sub Sun }, M{sub Sun} being the mass of Sun, as their most probable progenitors. Strongly magnetized white dwarfs having super-Chandrasekhar masses have already been established as potential candidates for the progenitors of peculiar Type Ia supernovae. Owing to the Landau quantization of the underlying electron degenerate gas, theoretical results yielded the observationally inferred mass range. Here, we sketch a possible evolutionary scenario by which super-Chandrasekhar white dwarfs could be formed by accretion on to a commonly observed magnetized white dwarf, invoking the phenomenon of flux freezing. This opens multiple possible evolution scenarios ending in supernova explosions of super-Chandrasekhar white dwarfs having masses within the range stated above. We point out that our proposal has observational support, such as the recent discovery of a large number of magnetized white dwarfs by the Sloan Digital Sky Survey.

  9. Constraints on the progenitor system of the type Ia supernova 2014J from pre-explosion Hubble space telescope imaging

    SciTech Connect (OSTI)

    Kelly, Patrick L.; Fox, Ori D.; Filippenko, Alexei V.; Shen, Ken J.; Zheng, WeiKang; Graham, Melissa L.; Tucker, Brad E.; Cenko, S. Bradley; Schaefer, Gail

    2014-07-20

    We constrain the properties of the progenitor system of the highly reddened Type Ia supernova (SN Ia) 2014J in Messier 82 (M82; d ? 3.5 Mpc). We determine the supernova (SN) location using Keck-II K-band adaptive optics images, and we find no evidence for flux from a progenitor system in pre-explosion near-ultraviolet through near-infrared Hubble Space Telescope (HST) images. Our upper limits exclude systems having a bright red giant companion, including symbiotic novae with luminosities comparable to that of RS Ophiuchi. While the flux constraints are also inconsistent with predictions for comparatively cool He-donor systems (T ? 35,000 K), we cannot preclude a system similar to V445 Puppis. The progenitor constraints are robust across a wide range of R{sub V} and A{sub V} values, but significantly greater values than those inferred from the SN light curve and spectrum would yield proportionally brighter luminosity limits. The comparatively faint flux expected from a binary progenitor system consisting of white dwarf stars would not have been detected in the pre-explosion HST imaging. Infrared HST exposures yield more stringent constraints on the luminosities of very cool (T < 3000 K) companion stars than was possible in the case of SN Ia 2011fe.

  10. Spectroscopic Properties of Star-Forming Host Galaxies and Type Ia Supernova Hubble Residuals in a Nearly Unbiased Sample

    SciTech Connect (OSTI)

    D'Andrea, Chris B.; et al.

    2011-12-20

    We examine the correlation between supernova host galaxy properties and their residuals on the Hubble diagram. We use supernovae discovered during the Sloan Digital Sky Survey II - Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M_r < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star-formation rates from host galaxies with active star formation. From a final sample of ~ 40 emission-line galaxies, we find that light-curve corrected Type Ia supernovae are ~ 0.1 magnitudes brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (> 3{\\sigma}) correlation between the Hubble residuals of Type Ia supernovae and the specific star-formation rate of the host galaxy. We comment on the importance of supernova/host-galaxy correlations as a source of systematic bias in future deep supernova surveys.

  11. Metabolomic profiling of the nectars of Aquilegia pubescens and <i>A. Canadensis

    SciTech Connect (OSTI)

    Noutsos, Christos; Perera, Ann M.; Nikolau, Basil J.; Seaver, Samuel M. D.; Ware, Doreen H.; Motta, Andrea

    2015-05-01

    To date, variation in nectar chemistry of flowering plants has not been studied in detail. Such variation exerts considerable influence on pollinator–plant interactions, as well as on flower traits that play important roles in the selection of a plant for visitation by specific pollinators. Over the past 60 years the Aquilegia genus has been used as a key model for speciation studies. In this study, we defined the metabolomic profiles of flower samples of two Aquilegia species, <i>A. Canadensis and <i>A. pubescens. We identified a total of 75 metabolites that were classified into six main categories: organic acids, fatty acids, amino acids, esters, sugars, and unknowns. The mean abundances of 25 of these metabolites were significantly different between the two species, providing insights into interspecies variation in floral chemistry. Using the PlantSEED biochemistry database, we found that the majority of these metabolites are involved in biosynthetic pathways. Finally, we explored the annotated genome of <i>A. coerulea, using the PlantSEED pipeline and reconstructed the metabolic network of Aquilegia. This network, which contains the metabolic pathways involved in generating the observed chemical variation, is now publicly available from the DOE Systems Biology Knowledge Base (KBase; http://kbase.us).

  12. Structural and magnetic properties of Sm{sub 2?x}Mn{sub x}O{sub 3} nanoparticles

    SciTech Connect (OSTI)

    Heiba, Zein K.; Mohamed, Mohamed Bakr; Fuess, H.

    2013-10-15

    Graphical abstract: - Highlights: C-type Sm{sub 2?x}Mn{sub x}O{sub 3} (0.0 ? x ?0.20) is prepared by solgel method. A maximum solubility of x = 0.15 is confirmed by X-ray diffraction, Raman and infrared techniques. Samples with x > 0.05 exhibit weak ferromagnetic properties; for x ? 0.05 antiferromagnetic behaviors is obtained. Correlation between magnetic behaviors and structural and microstructural parameters is discussed. - Abstract: Mixed oxide Sm{sub 2?x}Mn{sub x}O{sub 3} (SMO), x = 0.0, 0.05, 0.10, 0.15 and 0.20 were synthesized by a solgel process. A single phase solid solution is formed up to x = 0.15 which confirmed by using X-ray diffraction, Raman spectroscopy and infrared techniques. Crystal structure and microstructure analyses were performed by Rietveld refinement. Preferential cationic distribution, over the two crystallographic sites 8b and 24d of space group Ia3{sup }, is found for doped samples but with different extent. The r.m.s. microstrain ??{sub L}{sup 2}?{sup 1/2} depends on composition x in a systematic way emphasizing the preferential distribution. Magnetization measurements show that samples with x ? 0.05 have antiferromagnetic behavior, while samples with x > 0.05 exhibit a weak ferromagnetic behavior with magnetic phase transformation at 15 and 16 K for x = 0.1 and x = 0.15, respectively.

  13. Magnetic Moment Enhancement for Mn7 Cluster on Graphene

    SciTech Connect (OSTI)

    Liu, Xiaojie; Wang, Cai-Zhuang; Lin, Hai-Qing; Ho, Kai-Ming

    2014-08-21

    Mn7 cluster on graphene with different structural motifs and magnetic orders are investigated systematically by first-principles calculations. The calculations show that Mn7 on graphene prefers a two-layer motif and exhibits a ferrimagnetic coupling. The magnetic moment of the Mn7 cluster increases from 5.0 ?B at its free-standing state to about 6.0 ?B upon adsorption on graphene. Mn7 cluster also induces about 0.3 ?B of magnetic moment in the graphene layer, leading to an overall enhancement of 1.3 ?B magnetic moment for Mn7 on graphene. Detail electron transfer and bonding analysis have been carried out to investigate the origin of the magnetic enhancement.

  14. Radiogenic p-isotopes from type Ia supernova, nuclear physics uncertainties, and galactic chemical evolution compared with values in primitive meteorites

    SciTech Connect (OSTI)

    Travaglio, C.; Gallino, R.; Rauscher, T.; Dauphas, N.; Rpke, F. K.; Hillebrandt, W. E-mail: claudia.travaglio@b2fh.org

    2014-11-10

    The nucleosynthesis of proton-rich isotopes is calculated for multi-dimensional Chandrasekhar-mass models of Type Ia supernovae (SNe Ia) with different metallicities. The predicted abundances of the short-lived radioactive isotopes {sup 92}Nb, {sup 97,} {sup 98}Tc, and {sup 146}Sm are given in this framework. The abundance seeds are obtained by calculating s-process nucleosynthesis in the material accreted onto a carbon-oxygen white dwarf from a binary companion. A fine grid of s-seeds at different metallicities and {sup 13}C-pocket efficiencies is considered. A galactic chemical evolution model is used to predict the contribution of SN Ia to the solar system p-nuclei composition measured in meteorites. Nuclear physics uncertainties are critical to determine the role of SNe Ia in the production of {sup 92}Nb and {sup 146}Sm. We find that, if standard Chandrasekhar-mass SNe Ia are at least 50% of all SN Ia, they are strong candidates for reproducing the radiogenic p-process signature observed in meteorites.

  15. Ligand Bridging-Angle-Driven Assembly of Molecular Architectures Based on Quadruply Bonded Mo-Mo Dimers

    SciTech Connect (OSTI)

    Li, Jian-Rong; Yakovenko, Andrey A; Lu, Weigang; Timmons, Daren J; Zhuang, Wenjuan; Yuan, Daqiang; Zhou, Hong-Cai

    2010-12-15

    A systematic exploration of the assembly of Mo?(O?C-)?-based metalorganic molecular architectures structurally controlled by the bridging angles of rigid organic linkers has been performed. Twelve bridging dicarboxylate ligands were designed to be of different sizes with bridging angles of 0, 60, 90, and 120 while incorporating a variety of nonbridging functional groups, and these ligands were used as linkers. These dicarboxylate linkers assemble with quadruply bonded MoMo clusters acting as nodes to give 13 molecular architectures, termed metalorganic polygons/polyhedra with metal cluster node arrangements of a linear shape, triangle, octahedron, and cuboctahedron/anti-cuboctahedron. The syntheses of these complexes have been optimized and their structures determined by single-crystal X-ray diffraction. The results have shown that the shape and size of the resulting molecular architecture can be controlled by tuning the bridging angle and size of the linker, respectively. Functionalization of the linker can adjust the solubility of the ensuing molecular assembly but has little or no effect on the geometry of the product. Preliminary gas adsorption, spectroscopic, and electrochemical properties of selected members were also studied. The present work is trying to enrich metal-containing supramolecular chemistry through the inclusion of well-characterized quadruply bonded MoMo units into the structures, which can widen the prospect of additional electronic functionality, thereby leading to novel properties.

  16. Persistent C II absorption in the normal type Ia supernova 2002fk

    SciTech Connect (OSTI)

    Cartier, Rgis; Zelaya, Paula [Millennium Institute of Astrophysics, Casilla 36-D, Santiago (Chile); Hamuy, Mario; Maza, Jos; Gonzlez, Luis; Huerta, Leonor [Departamento de Astronoma, Universidad de Chile, Casilla 36-D, Santiago (Chile); Pignata, Giuliano [Departamento Ciencias Fisicas, Universidad Andres Bello, Av. Repblica 252, Santiago (Chile); Frster, Francisco [Center for Mathematical Modelling, Universidad de Chile, Avenida Blanco Encalada 2120, Piso 7, Santiago (Chile); Folatelli, Gaston [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Phillips, Mark M.; Morrell, Nidia; Contreras, Carlos; Roth, Miguel; Gonzlez, Sergio [Carnegie Institution of Washington, Las Campanas Observatory, Colina el Pino s/n, Casilla 601 (Chile); Krisciunas, Kevin; Suntzeff, Nicholas B. [Department of Physics and Astronomy, Texas A and M University, 4242 TAMU, College Station, TX 77843 (United States); Clocchiatti, Alejandro [Departamento de Astronoma y Astrofsica, Pontificia Universidad Catlica de Chile, Casilla 306, Santiago (Chile); Coppi, Paolo [Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States); Koviak, Kathleen, E-mail: rcartier@das.uchile.cl [Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 911901 (United States)

    2014-07-01

    We present well-sampled UBVRIJHK photometry of SN 2002fk starting 12 days before maximum light through 122 days after peak brightness, along with a series of 15 optical spectra from 4 to +95 days since maximum. Our observations show the presence of C II lines in the early-time spectra of SN 2002fk, expanding at 11,000 km s{sup 1} and persisting until 8 days past maximum light with a velocity of ?9000 km s{sup 1}. SN 2002fk is characterized by a small velocity gradient of v-dot {sub Si} {sub II}=26 km s{sup 1} day{sup 1}, possibly caused by an off-center explosion with the ignition region oriented toward the observer. The connection between the viewing angle of an off-center explosion and the presence of C II in the early-time spectrum suggests that the observation of C II could be also due to a viewing angle effect. Adopting the Cepheid distance to NGC 1309 we provide the first H {sub 0} value based on near-infrared (near-IR) measurements of a Type Ia supernova (SN) between 63.0 0.8 (3.4 systematic) and 66.7 1.0 (3.5 systematic) km s{sup 1} Mpc{sup 1}, depending on the absolute magnitude/decline rate relationship adopted. It appears that the near-IR yields somewhat lower (6%-9%) H {sub 0} values than the optical. It is essential to further examine this issue by (1) expanding the sample of high-quality near-IR light curves of SNe in the Hubble flow, and (2) increasing the number of nearby SNe with near-IR SN light curves and precise Cepheid distances, which affords the promise to deliver a more precise determination of H {sub 0}.

  17. LICENSE HISTORY MO.8 Petrolite Corporation, St. Louis

    Office of Legacy Management (LM)

    LICENSE HISTORY MO.8 Petrolite Corporation, St. Louis 07,16/93 l See attached Document and Pile Sumnary for MO.8 l License History: l 24-10452-01, 30-051175, 08/13/79. Loose H-3, I-131, P-32. l 24-10452-1, 10/30/64. K66 R. R. Annand et al Multiple. . 70-621, 12-15-61, SNM license for 0.5 kg. of U-235, 93% enriched as a fuel loading and star-up ~curce for Webster Groves, Missouri reactor. l Discussion: Historical documents for this site are limited. The only information available on work done

  18. Inverse spin Hall effect in Pt/(Ga,Mn)As

    SciTech Connect (OSTI)

    Nakayama, H.; Chen, L.; Chang, H. W.; Ohno, H.; Matsukura, F.

    2015-06-01

    We investigate dc voltages under ferromagnetic resonance in a Pt/(Ga,Mn)As bilayer structure. A part of the observed dc voltage is shown to originate from the inverse spin Hall effect. The sign of the inverse spin Hall voltage is the same as that in Py/Pt bilayer structure, even though the stacking order of ferromagnetic and nonmagnetic layers is opposite to each other. The spin mixing conductance at the Pt/(Ga,Mn)As interface is determined to be of the order of 10{sup 19 }m{sup −2}, which is about ten times greater than that of (Ga,Mn)As/p-GaAs.

  19. Policy Flash 2013-71 AL 2013-11 NON M&O CONTRACTOR BUSINESS SYSTEMS...

    Energy Savers [EERE]

    Policy Flash 2013-71 AL 2013-11 NON M&O CONTRACTOR BUSINESS SYSTEMS CLAUSES FOR SECTION H Policy Flash 2013-71 AL 2013-11 NON M&O CONTRACTOR BUSINESS SYSTEMS CLAUSES FOR SECTION H...

  20. Solution-based thermodynamic modeling of the Ni-Al-Mo system...

    Office of Scientific and Technical Information (OSTI)

    as (Al,Mo,Ni)0.75(Al,Mo,Ni)0.25. Thus, -fcc and -Ni3Al are modeled with a single Gibbs free energy function with appropriate treatment of the chemical ordering contribution. ...

  1. Domestic production of medical isotope Mo-99 moves a step closer

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

    Domestic production of medical isotope Mo-99 Domestic production of medical isotope Mo-99 moves a step closer Irradiated uranium fuel has been recycled and reused for molybdenum-99 (Mo-99) production, with virtually no losses in Mo-99 yields or uranium recovery. May 13, 2013 From left, Los Alamos scientists Roy Copping, Sean Reilly, and Daniel Rios. Copping examines the Buchi Multivapor P-12 Evaporator, and Reilly and Rios are at the Agilent Technologies Cary 60 UV-Vis Spectrometer. From left,

  2. Corrosion report for the U-Mo fuel concept

    SciTech Connect (OSTI)

    Henager, Jr., Charles H.; Bennett, Wendy D.; Doherty, Ann L.; Fuller, E. S.; Hardy, John S.; Omberg, Ronald P.

    2014-08-28

    The Fuel Cycle Research and Development (FCRD) program of the Office of Nuclear Energy (NE) has implemented a program to develop a Uranium-Molybdenum (U-Mo) metal fuel for Light Water Reactors (LWR)s. Uranium-Molybdenum fuel has the potential to provide superior performance based on its thermo-physical properties, which includes high thermal conductivity for less stored heat energy. With sufficient development, it may be able to provide the Light Water industry with a melt-resistant accident tolerant fuel with improved safety response. However, the corrosion of this fuel in reactor water environments needs to be further explored and optimized by additional alloying. The Pacific Northwest National Laboratory has been tasked with performing ex-reactor corrosion testing to characterize the performance of U-Mo fuel. This report documents the results of the effort to characterize and develop the U-Mo metal fuel concept for LWRs with regard to corrosion testing. The results of a simple screening test in buffered water at 30C using surface alloyed U-10Mo is documented and discussed. The screening test was used to guide the selection of several potential alloy improvements that were found and are recommended for further testing in autoclaves to simulate PWR water conditions more closely.

  3. NNSA Awards Mo-99 Cooperative Agreement to General Atomics | National

    National Nuclear Security Administration (NNSA)

    Nuclear Security Administration Mo-99 Cooperative Agreement to General Atomics | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Countering Nuclear Terrorism About Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Library Bios Congressional Testimony Fact Sheets Newsletters Press

  4. DOE - Office of Legacy Management -- Twin Cities Ammunition - MN 0-01

    Office of Legacy Management (LM)

    Twin Cities Ammunition - MN 0-01 FUSRAP Considered Sites Site: TWIN CITIES AMMUNITION (MN.0-01) Eliminated from further consideration under FUSRAP - Referred to DOD Designated Name: Not Designated Alternate Name: None Location: New Brighton , Minnesota MN.0-01-1 Evaluation Year: 1987 MN.0-01-2 Site Operations: Site was formerly licensed under 10CFR 70 by the NRC. MN.0-01-1 MN.0-01-2 Site Disposition: Eliminated - No Authority - Referred to DOD MN.0-01-1 Radioactive Materials Handled: None

  5. Systematic uncertainties associated with the cosmological analysis of the first Pan-STARRS1 type Ia supernova sample

    SciTech Connect (OSTI)

    Scolnic, D.; Riess, A.; Brout, D.; Rodney, S. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Rest, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Huber, M. E.; Tonry, J. L. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Foley, R. J.; Chornock, R.; Berger, E.; Soderberg, A. M.; Stubbs, C. W.; Kirshner, R. P.; Challis, P.; Czekala, I.; Drout, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Narayan, G. [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States); Smartt, S. J.; Botticella, M. T. [Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Schlafly, E. [Max Planck Institute for Astronomy, Konigstuhl 17, D-69117 Heidelberg (Germany); and others

    2014-11-01

    We probe the systematic uncertainties from the 113 Type Ia supernovae (SN Ia) in the Pan-STARRS1 (PS1) sample along with 197 SN Ia from a combination of low-redshift surveys. The companion paper by Rest et al. describes the photometric measurements and cosmological inferences from the PS1 sample. The largest systematic uncertainty stems from the photometric calibration of the PS1 and low-z samples. We increase the sample of observed Calspec standards from 7 to 10 used to define the PS1 calibration system. The PS1 and SDSS-II calibration systems are compared and discrepancies up to ?0.02 mag are recovered. We find uncertainties in the proper way to treat intrinsic colors and reddening produce differences in the recovered value of w up to 3%. We estimate masses of host galaxies of PS1 supernovae and detect an insignificant difference in distance residuals of the full sample of 0.037 0.031 mag for host galaxies with high and low masses. Assuming flatness and including systematic uncertainties in our analysis of only SNe measurements, we find w =?1.120{sub ?0.206}{sup +0.360}(Stat){sub ?0.291}{sup +0.269}(Sys). With additional constraints from Baryon acoustic oscillation, cosmic microwave background (CMB) (Planck) and H {sub 0} measurements, we find w=?1.166{sub ?0.069}{sup +0.072} and ?{sub m}=0.280{sub ?0.012}{sup +0.013} (statistical and systematic errors added in quadrature). The significance of the inconsistency with w = 1 depends on whether we use Planck or Wilkinson Microwave Anisotropy Probe measurements of the CMB: w{sub BAO+H0+SN+WMAP}=?1.124{sub ?0.065}{sup +0.083}.

  6. MID-IR SPECTRA OF TYPE Ia SN 2014J IN M82 SPANNING THE FIRST 4 MONTHS

    SciTech Connect (OSTI)

    Telesco, Charles M.; Li, Dan; Barnes, Peter J.; Marias, Naib; Zhang, Han; Hflich, Peter; lvarez, Carlos; Fernndez, Sergio; Rebolo, Rafael; Hough, James H.; Levenson, N. A.; Pantin, Eric; Roche, Patrick E-mail: phoeflich77@gmail.com

    2015-01-10

    We present a time series of 8-13 ?m spectra and photometry for SN 2014J obtained 57, 81, 108, and 137days after the explosion using CanariCam on the Gran Telescopio Canarias. This is the first mid-IR time series ever obtained for a Type Ia supernova (SN Ia). These observations can be understood within the framework of the delayed detonation model and the production of ?0.6 M {sub ?} of {sup 56}Ni, consistent with the observed brightness, the brightness decline relation, and the ?-ray fluxes. The [Co III] line at 11.888 ?m is particularly useful for evaluating the time evolution of the photosphere and measuring the amount of {sup 56}Ni and thus the mass of the ejecta. Late-time line profiles of SN 2014J are rather symmetric and not shifted in the rest frame. We see argon emission, which provides a unique probe of mixing in the transition layer between incomplete burning and nuclear statistical equilibrium. We may see [Fe III] and [Ni IV] emission, both of which are observed to be substantially stronger than indicated by our models. If the latter identification is correct, then we are likely observing stable Ni, which might imply central mixing. In addition, electron capture, also required for stable Ni, requires densities larger than ?1 10{sup 9}gcm{sup 3}, which are expected to be present only in white dwarfs close to the Chandrasekhar limit. This study demonstrates that mid-IR studies of SNe Ia are feasible from the ground and provide unique information, but it also indicates the need for better atomic data.

  7. Tuning magnetism of monolayer MoS{sub 2} by doping vacancy and applying strain

    SciTech Connect (OSTI)

    Zheng, Huiling; Yang, Baishun; Han, Ruilin; Du, Xiaobo; Yan, Yu; Wang, Dingdi

    2014-03-31

    In view of important role of inducing and manipulating the magnetism in two-dimensional materials for the development of low-dimensional spintronic devices, the influences of strain on electronic structure and magnetic properties of commonly observed vacancies doped monolayer MoS{sub 2} are investigated using first-principles calculations. It is shown that unstrained V{sub S}, V{sub S2}, and V{sub MoS3} doped monolayer MoS{sub 2} systems are nonmagnetic, while the ground state of unstrained V{sub MoS6} doped system is magnetic and the magnetic moment is contributed mainly by six Mo atoms around V{sub MoS6}. In particular, tensile strain can induce magnetic moments in V{sub S}, V{sub S2}, and V{sub MoS3} doped monolayer MoS{sub 2} due to the breaking of Mo–Mo metallic bonds around the vacancies, while the magnetization induced by V{sub MoS6} can be effectively manipulated by equibiaxial strain due to the change of Mo–Mo metallic bonds around V{sub MoS6} under strains.

  8. Defects Engineered Monolayer MoS2 for Improved Hydrogen Evolution Reaction

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

    Ye, Gonglan; Gong, Yongji; Lin, Junhao; Li, Bo; He, Yongmin; Pantelides, Sokrates T.; Zhou, Wu; Vajtai, Robert; Ajayan, Pulickel M.

    2016-01-13

    MoS2 is a promising, low-cost material for electrochemical hydrogen production due to its high activity and stability during the reaction. Our work represents an easy method to increase the hydrogen production in electrochemical reaction of MoS2 via defect engineering, and helps to understand the catalytic properties of MoS2.

  9. Nearby Supernova Factory Observations of SN 2005gj: Another TypeIa Supernova in a Massive Circumstellar Envelope

    SciTech Connect (OSTI)

    Aldering, G.; Antilogus, P.; Bailey, S.; Baltay, C.; Bauer, A.; Blanc, N.; Bongard, S.; Copin, Y.; Gangler, E.; Gilles, S.; Kessler, R.; Kocevski, D.; Lee, B.C.; Loken, S.; Nugent, P.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigaudier, G.; Scalzo, R.; Smadja, G.; Thomas, R.C.; Wang, L.; Weaver, B.A.; Rabinowitz, D.; Bauer, A.

    2006-06-01

    We report the independent discovery and follow-up observations of supernova 2005gj by the Nearby Supernova Factory. This is the second confirmed case of a ''hybrid'' Type Ia/IIn supernova, which like the prototype SN 2002ic, we interpret as the explosion of a white dwarf interacting with a circumstellar medium. Our early-phase photometry of SN 2005gj shows that the strength of the interaction between the supernova ejecta and circumstellar material is much stronger than for SN 2002ic. Our .rst spectrum shows a hot continuum with broad and narrow H{alpha} emission. Later spectra, spanning over 4 months from outburst, show clear Type Ia features combined with broad and narrow H{gamma}, H{beta},H{alpha} and He I {lambda}{lambda}5876,7065 in emission. At higher resolution, P Cygni profiles are apparent. Surprisingly, we also observe an inverted P Cygni profile for [O III] {lambda}5007. We find that the lightcurve and measured velocity of the unshocked circumstellar material imply mass loss as recently as 8 years ago. This is in contrast to SN 2002ic, for which an inner cavity in the circumstellar material was inferred. Within the context of the thin-shell approximation, the early lightcurve is well-described by a flat radial density profile for the circumstellar material. However, our decomposition of the spectra into Type Ia and shock emission components allows for little obscuration of the supernova, suggesting an aspherical or clumpy distribution for the circumstellar material. We suggest that the emission line velocity profiles arise from electron scattering rather than the kinematics of the shock. This is supported by the inferred high densities, and the lack of evidence for evolution in the line widths. Ground- and space-based photometry, and Keck spectroscopy, of the host galaxy are used to ascertain that the host galaxy has low metallicity (Z/Z{sub {circle_dot}} < 0.3; 95% confidence) and that this galaxy is undergoing a significant star formation event that began roughly 200 {+-} 70 Myr ago. We discuss the implications of these observations for progenitor models and cosmology using Type Ia supernovae.

  10. DISPLAYING THE HETEROGENEITY OF THE SN 2002cx-LIKE SUBCLASS OF TYPE Ia SUPERNOVAE WITH OBSERVATIONS OF THE Pan-STARRS-1 DISCOVERED SN 2009ku

    SciTech Connect (OSTI)

    Narayan, G.; Foley, R. J.; Berger, E.; Chornock, R.; Rest, A.; Soderberg, A. M.; Kirshner, R. P.; Botticella, M. T.; Smartt, S.; Valenti, S.; Huber, M. E.; Scolnic, D.; Grav, T.; Burgett, W. S.; Chambers, K. C.; Flewelling, H. A.; Gates, G.; Kaiser, N.; Magnier, E. A.; Morgan, J. S. E-mail: rfoley@cfa.harvard.edu

    2011-04-10

    SN 2009ku, discovered by Pan-STARRS-1, is a Type Ia supernova (SN Ia), and a member of the distinct SN 2002cx-like class of SNe Ia. Its light curves are similar to the prototypical SN 2002cx, but are slightly broader and have a later rise to maximum in g. SN 2009ku is brighter ({approx}0.6 mag) than other SN 2002cx-like objects, peaking at M{sub V} = -18.4 mag, which is still significantly fainter than typical SNe Ia. SN 2009ku, which had an ejecta velocity of {approx}2000 km s{sup -1} at 18 days after maximum brightness, is spectroscopically most similar to SN 2008ha, which also had extremely low-velocity ejecta. However, SN 2008ha had an exceedingly low luminosity, peaking at M{sub V} = -14.2 mag, {approx}4 mag fainter than SN 2009ku. The contrast of high luminosity and low ejecta velocity for SN 2009ku is contrary to an emerging trend seen for the SN 2002cx class. SN 2009ku is a counterexample of a previously held belief that the class was more homogeneous than typical SNe Ia, indicating that the class has a diverse progenitor population and/or complicated explosion physics. As the first example of a member of this class of objects from the new generation of transient surveys, SN 2009ku is an indication of the potential for these surveys to find rare and interesting objects.

  11. Unoccupied electronic states of icosahedral Al-Pd-Mn quasicrystals:

    Office of Scientific and Technical Information (OSTI)

    Evidence of image potential resonance and pseudogap (Journal Article) | DOE PAGES Unoccupied electronic states of icosahedral Al-Pd-Mn quasicrystals: Evidence of image potential resonance and pseudogap « Prev Next » Title: Unoccupied electronic states of icosahedral Al-Pd-Mn quasicrystals: Evidence of image potential resonance and pseudogap Authors: Maniraj, M. ; Rai, Abhishek ; Barman, S. R. ; Krajčí, M. ; Schlagel, D. L. ; Lograsso, T. A. ; Horn, K. Publication Date: 2014-09-05 OSTI

  12. CaMn2Al10: Itinerant Mn magnetism on the verge of magnetic order

    SciTech Connect (OSTI)

    Steinke, L.; Simonson, J. W.; Yin, W. -G.; Smith, G. J.; Kistner-Morris, J. J.; Zellman, S.; Puri, A.; Aronson, M. C.

    2015-07-24

    We report the discovery of CaMn2Al10, a metal with strong magnetic anisotropy and moderate electronic correlations. Magnetization measurements find a Curie-Weiss moment of 0.83?B/Mn, significantly reduced from the Hund's rule value, and the magnetic entropy obtained from specific heat measurements is correspondingly small, only ? 9% of Rln2. These results imply that the Mn magnetism is highly itinerant, a conclusion supported by density functional theory calculations that find strong Mn-Al hybridization. Consistent with the layered nature of the crystal structure, the magnetic susceptibility ? is anisotropic below 20 K, with a maximum ratio of ?[010]/?[001] ? 3.5. A strong power-law divergence ?(T) ~ T1.2 below 20 K implies incipient ferromagnetic order, an Arrott plot analysis of the magnetization suggests a vanishing low Curie temperature TC ~ 0. Our experiments indicate that CaMn2Al10 is a rare example of a system where the weak and itinerant Mn-based magnetism is poised on the verge of order.

  13. Thermal transport properties of metal/MoS{sub 2} interfaces from first principles

    SciTech Connect (OSTI)

    Mao, Rui; Kong, Byoung Don; Kim, Ki Wook, E-mail: kwk@ncsu.edu [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695-7911 (United States)

    2014-07-21

    Thermal transport properties at the metal/MoS{sub 2} interfaces are analyzed by using an atomistic phonon transport model based on the Landauer formalism and first-principles calculations. The considered structures include chemisorbed Sc(0001)/MoS{sub 2} and Ru(0001)/MoS{sub 2}, physisorbed Au(111)/MoS{sub 2}, as well as Pd(111)/MoS{sub 2} with intermediate characteristics. Calculated results illustrate a distinctive dependence of thermal transfer on the details of interfacial microstructures. More specifically, the chemisorbed case with a stronger bonding exhibits a generally smaller interfacial thermal resistance than the physisorbed. Comparison between metal/MoS{sub 2} and metal/graphene systems suggests that metal/MoS{sub 2} is significantly more resistive. Further examination of lattice dynamics identifies the presence of multiple distinct atomic planes and bonding patterns at the interface as the key origins of the observed large thermal resistance.

  14. Undercooled and rapidly quenched Ni-Mo alloys

    SciTech Connect (OSTI)

    Tewari, S.N.; Glasgow, T.K.

    1986-01-01

    Hypoeutectic, eutectic, and hypereutectic nickel-molybdenum alloys were rapidly solidified by both bulk undercooling and melt spinning techniques. Alloys were undercooled in both electromagnetic levitation and differential thermal analysis equipment. The rate of recalescence depended upon the degree of initial undercooling and the nature (faceted or nonfaceted) of the primary nucleating phase. Alloy melts were observed to undercool more in the presence of primary Beta (NiMo intermetallic) phase than in gamma (fcc solid solution) phase. Melt spinning resulted in an extension of molybdenum solid solubility in gamma nickel, from 28 to 37.5 at % Mo. Although the microstructures observed by undercooling and melt spinning were similar the microsegregation pattern across the gamma dendries was different. The range of microstructures evolved was analyzed in terms of the nature of the primary phase to nucleate, its subsequent dendritic growth, coarsening and fragmentation, and final solidification of interfenderitic liquid.

  15. IRRADIATION PERFORMANCE OF U-Mo MONOLITHIC FUEL

    SciTech Connect (OSTI)

    M.K. Meyer; J. Gan; J.-F. Jue; D.D. Keiser; E. Perez; A. Robinson; D.M. Wachs; N. Woolstenhulme; G.L. Hofman; Y.-S. Kim

    2014-04-01

    High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. UMo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

  16. Single Phase Melt Processed Powellite (Ba,Ca) MoO{sub 4} For The Immobilization Of Mo-Rich Nuclear Waste

    SciTech Connect (OSTI)

    Brinkman, Kyle; Marra, James; Fox, Kevin; Reppert, Jason; Crum, Jarrod; Tang, Ming

    2012-09-17

    Crystalline and glass composite materials are currently being investigated for the immobilization of combined High Level Waste (HLW) streams resulting from potential commercial fuel reprocessing scenarios. Several of these potential waste streams contain elevated levels of transition metal elements such as molybdenum (Mo). Molybdenum has limited solubility in typical silicate glasses used for nuclear waste immobilization. Under certain chemical and controlled cooling conditions, a powellite (Ba,Ca)MoO{sub 4} crystalline structure can be formed by reaction with alkaline earth elements. In this study, single phase BaMoO{sub 4} and CaMoO{sub 4} were formed from carbonate and oxide precursors demonstrating the viability of Mo incorporation into glass, crystalline or glass composite materials by a melt and crystallization process. X-ray diffraction, photoluminescence, and Raman spectroscopy indicated a long range ordered crystalline structure. In-situ electron irradiation studies indicated that both CaMoO{sub 4} and BaMoO{sub 4} powellite phases exhibit radiation stability up to 1000 years at anticipated doses with a crystalline to amorphous transition observed after 1 X 10{sup 13} Gy. Aqueous durability determined from product consistency tests (PCT) showed low normalized release rates for Ba, Ca, and Mo (<0.05 g/m{sup 2}).

  17. Functional MnMg{sub k} cation complexes in GaN featured by Raman spectroscopy

    SciTech Connect (OSTI)

    Devillers, T. Bonanni, A.; Leite, D. M. G.; Department of Physics, So Paulo State University, BauruSP ; Dias da Silva, J. H.

    2013-11-18

    The evolution of the optical branch in the Raman spectra of (Ga,Mn)N:Mg epitaxial layers as a function of the Mn and Mg concentrations, reveals the interplay between the two dopants. We demonstrate that the various Mn-Mg-induced vibrational modes can be understood in the picture of functional MnMg{sub k} complexes formed when substitutional Mn cations are bound to k substitutional Mg through nitrogen atoms, the number of ligands k being driven by the ratio between the Mg and the Mn concentrations.

  18. Effect of Mn substitution on the transport properties of co-sputtered

    Office of Scientific and Technical Information (OSTI)

    Fe{sub 3-x}Mn{sub x}Si epilayers (Journal Article) | SciTech Connect Journal Article: Effect of Mn substitution on the transport properties of co-sputtered Fe{sub 3-x}Mn{sub x}Si epilayers Citation Details In-Document Search Title: Effect of Mn substitution on the transport properties of co-sputtered Fe{sub 3-x}Mn{sub x}Si epilayers Motivated by the theoretical calculations that Fe{sub 3-x}Mn{sub x}Si can simultaneously exhibit a high spin polarization with a high Curie temperature to be

  19. Mn-Fe base and Mn-Cr-Fe base austenitic alloys

    DOE Patents [OSTI]

    Brager, Howard R. (Richland, WA); Garner, Francis A. (Richland, WA)

    1987-01-01

    Manganese-iron base and manganese-chromium-iron base austenitic alloys designed to have resistance to neutron irradiation induced swelling and low activation have the following compositions (in weight percent): 20 to 40 Mn; up to about 15 Cr; about 0.4 to about 3.0 Si; an austenite stabilizing element selected from C and N, alone or in combination with each other, and in an amount effective to substantially stabilize the austenite phase, but less than about 0.7 C, and less than about 0.3 N; up to about 2.5 V; up to about 0.1 P; up to about 0.01 B; up to about 3.0 Al; up to about 0.5 Ni; up to about 2.0 W; up to about 1.0 Ti; up to about 1.0 Ta; and with the remainder of the alloy being essentially iron.

  20. Synthesis, characterization and electrochemical performance of Al-substituted Li₂MnO₃

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

    Dhital, Chetan; Huq, Ashfia; Paranthaman, Mariappan Parans; Manivannan, Ayyakkannu; Torres-Castro, Loraine; Shojan, Jifi; Julien, Christian M.; Katiyar, Ram S.

    2015-08-08

    Li2MnO3 is known to be electrochemically inactive due to Mn in tetravalent oxidation state. Several compositions such as Li2MnO3 , Li1.5Al0.17MnO3, Li1.0Al0.33MnO3 and Li0.5Al0.5MnO3 were synthesized by a sol–gel Pechini method. All the samples were characterized with x-ray diffraction, Raman, x-ray photoelectron spectroscopy, scanning electron microscopy, Tap density and BET analyzer. X-ray diffraction patterns indicated the presence of monoclinic phase for pristine Li2MnO3and mixed monoclinic/spinel phases (Li2 - xMn1 - yAlx + yO3 + z) for Al-substituted Li2MnO3compounds. The Al substitution seems to occur both at Li and Mn sites, which could explain the presence of spinel phase. X-ray photoelectronmore » spectroscopy for Mn 2p orbital reveals a significant decrease in binding energy for Li1.0Al0.33MnO3 and Li0.5Al0.5MnO3 compounds. Cyclic voltammetry, charge/discharge cycles and electrochemical impedance spectroscopy were also performed. A discharge capacity of 24 mAh g-1 for Li2MnO3, 68 mAh g-1 for Li1.5Al0.17MnO3, 58 mAh g-1 for Li1.0Al0.33MnO3 and 74 mAh g-1 for Li0.5Al0.5MnO3 were obtained. As a result, aluminum substitutions increased the formation of spinel phase which is responsible for cycling.« less

  1. Resonant spin tunneling in randomly oriented nanospheres of Mn?? acetate

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

    Lendinez, S.; Billinge, S. J. L.; Zarzuela, R.; Tejada, J.; Terban, M. W.; Espin, J.; Imaz, I.; Maspoch, D.; Chudnovsky, E. M.

    2015-01-06

    We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn?? acetate have been fabricated and characterized by chemical, infrared, TEM, X-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn?? acetate crystal in the field parallel to the easy axis.Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for amoresingle crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by re-analyzing the old data on a powdered sample of non-oriented micron-size crystals of Mn?? acetate. Our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets.less

  2. Climate Action Champions: Minneapolis, MN | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Minneapolis, MN Climate Action Champions: Minneapolis, MN The City of Minneapolis, or the “City of Lakes”, lies on both banks of the Mississippi River in Minnesota. Once the flour milling capital of the world, the larger of the Twin Cities is now a thriving Midwestern economic hub. │ Photo courtesy of Meet Minneapolis. The City of Minneapolis, or the "City of Lakes", lies on both banks of the Mississippi River in Minnesota. Once the flour milling capital of the world,

  3. Pulsed laser deposition of Mn doped CdSe quantum dots for improved solar cell performance

    SciTech Connect (OSTI)

    Dai, Qilin; Wang, Wenyong E-mail: jtang2@uwyo.edu; Tang, Jinke E-mail: jtang2@uwyo.edu; Sabio, Erwin M.

    2014-05-05

    In this work, we demonstrate (1) a facile method to prepare Mn doped CdSe quantum dots (QDs) on Zn{sub 2}SnO{sub 4} photoanodes by pulsed laser deposition and (2) improved device performance of quantum dot sensitized solar cells of the Mn doped QDs (CdSe:Mn) compared to the undoped QDs (CdSe). The band diagram of photoanode Zn{sub 2}SnO{sub 4} and sensitizer CdSe:Mn QD is proposed based on the incident-photon-to-electron conversion efficiency (IPCE) data. Mn-modified band structure leads to absorption at longer wavelengths than the undoped CdSe QDs, which is due to the exchange splitting of the CdSe:Mn conduction band by the Mn dopant. Three-fold increase in the IPCE efficiency has also been observed for the Mn doped samples.

  4. Multiscale twin hierarchy in NiMnGa shape memory alloys with...

    Office of Scientific and Technical Information (OSTI)

    Multiscale twin hierarchy in NiMnGa shape memory alloys with Fe and Cu Citation Details In-Document Search Title: Multiscale twin hierarchy in NiMnGa shape memory alloys with Fe ...

  5. Phase stability of the SrMn O 3 hexagonal perovskite system at...

    Office of Scientific and Technical Information (OSTI)

    Phase stability of the SrMn O 3 hexagonal perovskite system at high pressure and temperature Title: Phase stability of the SrMn O 3 hexagonal perovskite system at highpressure and ...

  6. High spin polarization in CoFeMnGe equiatomic quaternary Heusler...

    Office of Scientific and Technical Information (OSTI)

    Title: High spin polarization in CoFeMnGe equiatomic quaternary Heusler alloy We report the structure, magnetic property, and spin polarization of CoFeMnGe equiatomic...

  7. Magnetocaloric effect of Pr2Fe17-x Mn x alloys (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Magnetocaloric effect of Pr2Fe17-x Mn x alloys Citation Details In-Document Search Title: Magnetocaloric effect of Pr2Fe17-x Mn x ...

  8. Mixing antiferromagnets to tune NiFe-[IrMn/FeMn] interfacial spin-glasses, grains thermal stability, and related exchange bias properties

    SciTech Connect (OSTI)

    Akmaldinov, K.; Ducruet, C.; Portemont, C.; Joumard, I.; Prejbeanu, I. L.; Dieny, B.; Baltz, V.

    2014-05-07

    Spintronics devices and in particular thermally assisted magnetic random access memories require a wide range of ferromagnetic/antiferromagnetic (F/AF) exchange bias (EB) properties and subsequently of AF materials to fulfil diverse functionality requirements for the reference and storage. For the reference layer, large EB energies and high blocking temperature (T{sub B}) are required. In contrast, for the storage layer, mostly moderate T{sub B} are needed. One of the present issues is to find a storage layer with properties intermediate between those of IrMn and FeMn and in particular: (i) with a T{sub B} larger than FeMn for better stability at rest-T but lower than IrMn to reduce power consumption at write-T and (ii) with improved magnetic interfacial quality, i.e., with reduced interfacial glassy character for lower properties dispersions. To address this issue, the EB properties of F/AF based stacks were studied for various mixed [IrMn/FeMn] AFs. In addition to EB loop shifts, the F/AF magnetic interfacial qualities and the AF grains thermal stability are probed via measurements of the low- and high-temperature contributions to the T{sub B} distributions, respectively. A tuning of the above three parameters is observed when evolving from IrMn to FeMn via [IrMn/FeMn] repetitions.

  9. Domestic production of medical isotope Mo-99 moves a step closer

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

    partners, including Morgridge Institute for Research-SHINE Medical Technologies (MIR-SHINE), which proposes to use a particle accelerator to produce Mo-99 from a mildly...

  10. Experimental activities supporting commercial U.S. accelerator production of 99-Mo

    SciTech Connect (OSTI)

    Dale, Gregory E [Los Alamos National Laboratory; Chemerisov, Sergey D [ANL; Vandegrift, George F [ANL

    2010-01-01

    {sup 99m}Tc, the daughter product of {sup 99}Mo, is the most commonly used radioisotope for nuclear medicine in the U.S. Experiments are being performed at Los Alamos National Laboratory and Argonne National Laboratory to demonstrate production of {sup 99}Mo using accelerators. The {sup 100}Mo({gamma},n){sup 99}Mo reaction in an enriched {sup 100}Mo target is currently under investigation. Three scaled low-power production experiments using a 20-MeV electron linac at Argonne have been performed to date. Two of these experiments used natural Mo targets and produced a total of 613 {mu}C of {sup 99}Mo. The third experiment used an enriched {sup 100}Mo target and produced 10.5 mCi of {sup 99}Mo. Following irradiation the targets were dissolved and the low specific activity solution was processed through an ARSII generator from NorthStar Medical Radioisotopes. Yields of {sup 99m}Tc >95% have been observed.

  11. Conceptual design of a new homogeneous reactor for medical radioisotope Mo-99/Tc-99m production

    SciTech Connect (OSTI)

    Liem, Peng Hong [Nippon Advanced Information Service (NAIS Co., Inc.) Scientific Computational Division, 416 Muramatsu, Tokaimura, Ibaraki (Japan); Tran, Hoai Nam [Chalmers University of Technology, Dept. of Applied Physics, Div. of Nuclear Engineering, SE-412 96 Gothenburg (Sweden); Sembiring, Tagor Malem [National Nuclear Energy Agency (BATAN), Center for Reactor Technology and Nuclear Safety, Kawasan Puspiptek, Serpong, Tangerang Selatan, Banten (Indonesia); Arbie, Bakri [PT MOTAB Technology, Kedoya Elok Plaza Blok DA 12, Jl. Panjang, Kebun Jeruk, Jakarta Barat (Indonesia)

    2014-09-30

    To partly solve the global and regional shortages of Mo-99 supply, a conceptual design of a nitrate-fuel-solution based homogeneous reactor dedicated for Mo-99/Tc-99m medical radioisotope production is proposed. The modified LEU Cintichem process for Mo-99 extraction which has been licensed and demonstrated commercially for decades by BATAN is taken into account as a key design consideration. The design characteristics and main parameters are identified and the advantageous aspects are shown by comparing with the BATAN's existing Mo-99 supply chain which uses a heterogeneous reactor (RSG GAS multipurpose reactor)

  12. Solution-based thermodynamic modeling of the Ni-Al-Mo system using

    Office of Scientific and Technical Information (OSTI)

    first-principles calculations (Journal Article) | SciTech Connect Solution-based thermodynamic modeling of the Ni-Al-Mo system using first-principles calculations Citation Details In-Document Search Title: Solution-based thermodynamic modeling of the Ni-Al-Mo system using first-principles calculations A solution-based thermodynamic description of the ternary Ni-Al-Mo system is developed here, incorporating first-principles calculations and reported modeling of the binary Ni-Al, Ni-Mo and

  13. Synthesis of molybdenum disulfide (MoS{sub 2}) for lithium ion battery applications

    SciTech Connect (OSTI)

    Feng Chuanqi; Ma Jun; Li Hua; Zeng Rong; Guo Zaiping; Liu Huakun

    2009-09-15

    This paper reports the use of a rheological phase reaction method for preparing MoS{sub 2} nanoflakes. The characterization by powder X-ray diffraction indicated that MoS{sub 2} had been formed. High resolution electron microscopy observation revealed that the as-prepared MoS{sub 2} nanoflakes had started to curve and partly form MoS{sub 2} nanotubes. The lithium intercalation/de-intercalation behavior of as-prepared MoS{sub 2} nanoflake electrode was also investigated. It was found that the MoS{sub 2} nanoflake electrode exhibited higher specific capacity, with very high cycling stability, compared to MoS{sub 2} nanoparticle electrode. The possible reasons for the high electrochemical performance of the nanoflakes electrodes are also discussed. The outstanding electrochemical properties of MoS{sub 2} nanoflakes obtained by this method make it possible for MoS{sub 2} to be used as a promising anode material.

  14. Mechanically Activated Combustion Synthesis of MoSi2-Based Composites

    SciTech Connect (OSTI)

    Shafirovich, Evgeny

    2015-09-30

    The thermal efficiency of gas-turbine power plants could be dramatically increased by the development of new structural materials based on molybdenum silicides and borosilicides, which can operate at temperatures higher than 1300 °C with no need for cooling. A major challenge, however, is to simultaneously achieve high oxidation resistance and acceptable mechanical properties at high temperatures. One approach is based on the fabrication of MoSi2-Mo5Si3 composites that combine high oxidation resistance of MoSi2 and good mechanical properties of Mo5Si3. Another approach involves the addition of boron to Mo-rich silicides for improving their oxidation resistance through the formation of a borosilicate surface layer. In particular, materials based on Mo5SiB2 phase are promising materials that offer favorable combinations of high temperature mechanical properties and oxidation resistance. However, the synthesis of Mo-Si-B multi-phase alloys is difficult because of their extremely high melting temperatures. Mechanical alloying has been considered as a promising method, but it requires long milling times, leading to large energy consumption and contamination of the product by grinding media. In the reported work, MoSi2-Mo5Si3 composites and several materials based on Mo5SiB2 phase have been obtained by mechanically activated self-propagating high-temperature synthesis (MASHS). Short-term milling of Mo/Si mixture in a planetary mill has enabled a self-sustained propagation of the combustion front over the mixture pellet, leading to the formation of MoSi2-T1 composites. Combustion of Mo/Si/B mixtures for the formation of T2 phase becomes possible if the composition is designed for the addition of more exothermic reactions leading to the formation of MoB, TiC, or TiB2. Upon ignition, Mo/Si/B and Mo/Si/B/Ti mixtures exhibited spin combustion, but the products were porous, contained undesired secondary phases, and had low oxidation resistance. It has been shown that use of SHS compaction (quasi-isostatic pressing after combustion) significantly improves oxidation resistance of the obtained MoSi2-Mo5Si3 composites. The “chemical oven” technique has been successfully employed to fabricate low-porous Mo5SiB2–TiC, Mo5SiB2–TiB2, and Mo–Mo5SiB2–Mo3Si materials. Among them, Mo5SiB2–TiB2 material possesses good mechanical properties and simultaneously exhibits excellent oxidation resistance at temperatures up to 1500 °C.

  15. Recovery of Mo/Si multilayer coated optical substrates

    DOE Patents [OSTI]

    Baker, S.L.; Vernon, S.P.; Stearns, D.G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO{sub 2} overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates. 5 figs.

  16. Recovery of Mo/Si multilayer coated optical substrates

    DOE Patents [OSTI]

    Baker, Sherry L.; Vernon, Stephen P.; Stearns, Daniel G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO.sub.2 overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates.

  17. Microsoft Word - chapter FeCrMo_ver2.doc

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

    Reference on Hydrogen Compatibility of Materials Low-Alloy Ferritic Steels: Tempered Fe-Cr-Mo Alloys (code 1211) Prepared by: B.P. Somerday, Sandia National Laboratories Editors C. San Marchi B.P. Somerday Sandia National Laboratories This report may be updated and revised periodically in response to the needs of the technical community; up-to-date versions can be requested from the editors at the address given below or downloaded at http://www.ca.sandia.gov/matlsTechRef/ . The success of this

  18. Greenfield Alternative Study LEU-Mo Fuel Fabrication Facility

    SciTech Connect (OSTI)

    Washington Division of URS

    2008-07-01

    This report provides the initial “first look” of the design of the Greenfield Alternative of the Fuel Fabrication Capability (FFC); a facility to be built at a Greenfield DOE National Laboratory site. The FFC is designed to fabricate LEU-Mo monolithic fuel for the 5 US High Performance Research Reactors (HPRRs). This report provides a pre-conceptual design of the site, facility, process and equipment systems of the FFC; along with a preliminary hazards evaluation, risk assessment as well as the ROM cost and schedule estimate.

  19. Characterization of modified 9 Cr-1 Mo steel extruded pipe

    SciTech Connect (OSTI)

    Sikka, V.K.; Hart, M.D.

    1985-04-01

    The fabrication of hot-extruded pipe of modified 9 Cr-1 Mo steel at Cameron Iron Works is described. The report also deals with the tempering response; tensile, Charpy impact, and creep properties; and microstructure of the hot-extruded pipe. The tensile properties of the pipe are compared with the average and average -1.65 standard error of estimate curves for various product forms of several commercial heats of this alloy. The creep-rupture properties are compared with the average curve for various product forms of the commercial heats.

  20. d::;":,",:::,, ST. LOUIS.7. MO,

    Office of Legacy Management (LM)

    i ,' ~CKRODT CHEMICAL d::;":,",:::,, ST. LOUIS.7. MO, PiARCH 14, ,jq;ll MR. H. L. PRICE, GIRECTOR ,.' , . . DIVISION OF LICENSING AND F~EG~~LATION ,... L.' S. ATOMIC ' ENERGY COMMISSION :' ;._ hASHINGT0N 25, D. c. T> "-VW-; PEAR P;R. FRICE: PURSUANT To THE PROVISIONS OF 10 CF? FART 20, PARAGRAPH 2O-.lO3, (4 (31, THE NUCLEAR DIVISI:IN, COMMERC I AL ~PERAT I ONS DF MALL- INCKRODT ' CHEMICAL b:ORKS WOULD LIKE TO MAKE.APPLlCATlON FOR A MODIFICATION TO LICENSE NO. SNPI 33 TO INCLUDE

  1. DOE/NNSA - MoD Certification Form

    Office of Environmental Management (EM)

    14 (01/2014) UNITED STATES DEPARTMENT OF ENERGY NATIONAL NUCLEAR SECURITY ADMINISTRATION UNITED KINGDOM MINISTRY OF DEFENCE DOE or MoD CERTIFICATION * Select as applicable SECTION I - DOE/NNSA MARK QUALITY MATERIAL This material has been accepted by the DOE/NNSA or inspected and accepted by DOE/NNSA contractor(s) authorized to acquire such material and is of like quality to that used in DOE/NNSA weapons or in support thereof. (Note: Application of UK Stamp is by DOE/NNSA only) Signature: Date:

  2. Epitaxial growth of intermetallic MnPt films on oxides and large exchange bias

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

    Liu, Zhiqi; Biegalski, Michael D.; Hsu, Shang-Lin; Shang, Shunli; Marker, Cassie; Liu, Jian; Li, Li; Fan, Lisha S.; Meyer, Tricia L.; Wong, Anthony T.; et al

    2015-11-05

    High-quality epitaxial growth of intermetallic MnPt films on oxides is achieved, with potential for multiferroic heterostructure applications. Antisite-stabilized spin-flipping induces ferromagnetism in MnPt films, although it is robustly antiferromagnetic in bulk. Thus, highly ordered antiferromagnetic MnPt films exhibit superiorly large exchange coupling with a ferromagnetic layer.

  3. Cationic disorder and Mn{sup 3+}/Mn{sup 4+} charge ordering in the B? and B? sites of Ca{sub 3}Mn{sub 2}NbO{sub 9} perovskite: a comparison with Ca{sub 3}Mn{sub 2}WO{sub 9}

    SciTech Connect (OSTI)

    Lpez, C.A.; Saleta, M.E.; Pedregosa, J.C.; Snchez, R.D.; Alonso, J.A.; and others

    2014-02-15

    We describe the preparation, crystal structure determination, magnetic and transport properties of two novel Mn-containing perovskites, with a different electronic configuration for Mn atoms located in B site. Ca{sub 3}Mn{sup 3+}{sub 2}WO{sub 9} and Ca{sub 3}Mn{sup 3+/4+}{sub 2}NbO{sub 9} were synthesized by standard ceramic procedures; the crystallographic structure was studied from X-ray powder diffraction (XRPD) and neutron powder diffraction (NPD). Both phases exhibit a monoclinic symmetry (S.G.: P2{sub 1}/n); Ca{sub 3}Mn{sub 2}WO{sub 9} presents a long-range ordering over the B sites, whereas Ca{sub 3}Mn{sub 2}NbO{sub 9} is strongly disordered. By in-situ NPD, the temperature evolution of the structure study presents an interesting evolution in the octahedral size (?MnO?) for Ca{sub 3}Mn{sub 2}NbO{sub 9}, driven by a charge ordering effect between Mn{sup 3+} and Mn{sup 4+} atoms, related to the anomaly observed in the transport measurements at T?160 K. Both materials present a magnetic order below T{sub C}=30 K and 40 K for W and Nb materials, respectively. The magneto-transport measurements display non-negligible magnetoresistance properties in the paramagnetic regime. - Graphical abstract: Comparison between the octahedron size and the magnetic behaviour for Ca{sub 3}Mn{sub 2}NbO{sub 9} in the temperature region where the charge and magnetic order occur. Display Omitted - Highlights: Two novel Mn-containing double perovskites were obtained by solid-state reactions. Both double perovskites are monoclinic (P2{sub 1}/n) determined by XRPD and NPD. Ca{sub 3}Mn{sub 2}WO{sub 9} contains Mn{sup 3+} while Ca{sub 3}Mn{sub 2}NbO{sub 9} includes mixed-valence cations Mn{sup 3+}/Mn{sup 4+}. Ca{sub 3}Mn{sub 2}NbO{sub 9} presents a charge-ordering effect between Mn{sup 3+} and Mn{sup 4+} evidenced by NPD. The magnetic and transport studies evidenced the charge ordering in Ca{sub 3}Mn{sub 2}NbO{sub 9}.

  4. Clarification of enhanced ferromagnetism in Be-codoped InMnP fabricated using Mn/InP:Be bilayers grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Shon, Yoon; Lee, Sejoon; Taek Yoon, Im; Jeon, H. C.; Lee, D. J.; Kang, T. W.; Song, J. D.; Yoon, Chong S.; Kim, D. Y.; Park, C. S.

    2011-11-07

    The p-type InMnP:Be epilayers were prepared by the sequential growth of Mn/InP:Be bilayers using molecular-beam-epitaxy and the subsequent in-situ annealing at 200-300 deg. C. In triple-axis x-ray diffraction patterns, the samples revealed a shoulder peak indicative of intrinsic InMnP. The ferromagnetic transition in InMnP:Be was observed to occur at the elevated temperature of {approx}140 K, and the ferromagnetic spin-domains clearly appeared in magnetic force microscopy images. The improved ferromagnetic properties are attributed to the increased p-d hybridation due to high p-type conductivity of InMnP:Be (p {approx} 10{sup 20 }cm{sup -3}). The results suggest that enhanced ferromagnetism can be effectively obtained from Be-codoped InMnP.

  5. Characterization of U-Mo Foils for AFIP-7

    SciTech Connect (OSTI)

    Edwards, Danny J.; Ermi, Ruby M.; Schemer-Kohrn, Alan L.; Overman, Nicole R.; Henager, Charles H.; Burkes, Douglas; Senor, David J.

    2012-11-07

    Twelve AFIP in-process foil samples, fabricated by either Y-12 or LANL, were shipped from LANL to PNNL for potential characterization using optical and scanning electron microscopy techniques. Of these twelve, nine different conditions were examined to one degree or another using both techniques. For this report a complete description of the results are provided for one archive foil from each source of material, and one unirradiated piece of a foil of each source that was irradiated in the Advanced Test Reactor. Additional data from two other LANL conditions are summarized in very brief form in an appendix. The characterization revealed that all four characterized conditions contained a cold worked microstructure to different degrees. The Y-12 foils exhibited a higher degree of cold working compared to the LANL foils, as evidenced by the highly elongated and obscure U-Mo grain structure present in each foil. The longitudinal orientations for both of the Y-12 foils possesses a highly laminar appearance with such a distorted grain structure that it was very difficult to even offer a range of grain sizes. The U-Mo grain structure of the LANL foils, by comparison, consisted of a more easily discernible grain structure with a mix of equiaxed and elongated grains. Both materials have an inhomogenous grain structure in that all of the characterized foils possess abnormally coarse grains.

  6. Role of t{sub 2g} electrons in Mn-Tb coupling of multiferroic TbMnO{sub 3}

    SciTech Connect (OSTI)

    Guo, Y. Y.; Wang, Y. L.; Liu, J.-M.; Wei, T.

    2014-08-14

    We investigate the effect of Cr-doping in polycrystalline TbMn{sub 1?x}Cr{sub x}O{sub 3} (x???6%) ceramics on the magnetism, ferroelectricity, and dielectricity. The Cr substitution gradually suppresses the ferroelectricity induced by the Mn spiral spin ordering, and results in a stronger modulation of polarization by magnetic field with increasing x. However, the transition temperature T{sub Tb} corresponding to onset of Tb magnetic ordering has barely shifted with Cr doping. In other words, although the Cr-doping obviously disrupts the Mn spiral spin ordering, the exchange field J{sub Mn-Tb} acting on the Tb moments from the Mn-spin structure is hardly impacted. Our work demonstrates that the e{sub g} electron of Mn{sup 3+} plays an important role in forming the Mn spiral spin order, but the f-d exchange interaction between the Mn 3d spins and the Tb 4f moments in multiferroic TbMnO{sub 3} almost involves only the t{sub 2g} electrons.

  7. Effect of Mn substitution on the transport properties of co-sputtered Fe{sub 3−x}Mn{sub x}Si epilayers

    SciTech Connect (OSTI)

    Tang, M.; Jin, C.; Bai, H. L.

    2014-11-07

    Motivated by the theoretical calculations that Fe{sub 3−x}Mn{sub x}Si can simultaneously exhibit a high spin polarization with a high Curie temperature to be applied in spintronic devices, and in order to further study the effect of Mn contents on the physical properties of Fe{sub 3−x}Mn{sub x}Si, we have investigated the effect of Mn substitution on the transport properties of epitaxial Fe{sub 3−x}Mn{sub x}Si (0≤x≤1) films systematically. The Fe{sub 3−x}Mn{sub x}Si films were epitaxially grown on MgO(001) plane with 45° rotation. The magnetization for various x shows enhanced irreversibility, implying the antiferromagnetic ordering induced by the substitution of Mn. A metal-semiconductor crossover was observed due to the enhanced disorders of interactions and the local lowering of symmetry induced by the substitution of Mn. The single-domain state in the Fe{sub 3−x}Mn{sub x}Si films leads to twofold symmetric curves of the anisotropic magnetoresistance and planar Hall resistivity.

  8. Cosmological constraints from measurements of type Ia supernovae discovered during the first 1.5 yr of the Pan-STARRS1 survey

    SciTech Connect (OSTI)

    Rest, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Scolnic, D.; Riess, A.; Rodney, S.; Brout, D. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Foley, R. J.; Chornock, R.; Berger, E.; Soderberg, A. M.; Stubbs, C. W.; Kirshner, R. P.; Challis, P.; Czekala, I.; Drout, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Huber, M. E.; Tonry, J. L. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Narayan, G. [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States); Smartt, S. J. [Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT71NN (United Kingdom); Schlafly, E. [Max Planck Institute for Astronomy, Knigstuhl 17, D-69117 Heidelberg (Germany); Botticella, M. T. [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli (Italy); and others

    2014-11-01

    We present griz {sub P1} light curves of 146 spectroscopically confirmed Type Ia supernovae (SNe Ia; 0.03 < z < 0.65) discovered during the first 1.5 yr of the Pan-STARRS1 Medium Deep Survey. The Pan-STARRS1 natural photometric system is determined by a combination of on-site measurements of the instrument response function and observations of spectrophotometric standard stars. We find that the systematic uncertainties in the photometric system are currently 1.2% without accounting for the uncertainty in the Hubble Space Telescope Calspec definition of the AB system. A Hubble diagram is constructed with a subset of 113 out of 146 SNe Ia that pass our light curve quality cuts. The cosmological fit to 310 SNe Ia (113 PS1 SNe Ia + 222 light curves from 197 low-z SNe Ia), using only supernovae (SNe) and assuming a constant dark energy equation of state and flatness, yields w=?1.120{sub ?0.206}{sup +0.360}(Stat){sub ?0.291}{sup +0.269}(Sys). When combined with BAO+CMB(Planck)+H {sub 0}, the analysis yields ?{sub M}=0.280{sub ?0.012}{sup +0.013} and w=?1.166{sub ?0.069}{sup +0.072} including all identified systematics. The value of w is inconsistent with the cosmological constant value of 1 at the 2.3? level. Tension endures after removing either the baryon acoustic oscillation (BAO) or the H {sub 0} constraint, though it is strongest when including the H {sub 0} constraint. If we include WMAP9 cosmic microwave background (CMB) constraints instead of those from Planck, we find w=?1.124{sub ?0.065}{sup +0.083}, which diminishes the discord to <2?. We cannot conclude whether the tension with flat ?CDM is a feature of dark energy, new physics, or a combination of chance and systematic errors. The full Pan-STARRS1 SN sample with ?three times as many SNe should provide more conclusive results.

  9. Plutonium Oxidation and Subsequent Reduction by Mn (IV) Minerals

    SciTech Connect (OSTI)

    KAPLAN, DANIEL

    2005-09-13

    Plutonium sorbed to rock tuff was preferentially associated with manganese oxides. On tuff and synthetic pyrolusite (Mn{sup IV}O{sub 2}), Pu(IV) or Pu(V) was initially oxidized, but over time Pu(IV) became the predominant oxidation state of sorbed Pu. Reduction of Pu(V/VI), even on non-oxidizing surfaces, is proposed to result from a lower Gibbs free energy of the hydrolyzed Pu(IV) surface species versus that of the Pu(V) or Pu(VI) surface species. This work suggests that despite initial oxidation of sorbed Pu by oxidizing surfaces to more soluble forms, the less mobile form of Pu, Pu(IV), will dominate Pu solid phase speciation during long term geologic storage. The safe design of a radioactive waste or spent nuclear fuel geologic repository requires a risk assessment of radionuclides that may potentially be released into the surrounding environment. Geochemical knowledge of the radionuclide and the surrounding environment is required for predicting subsurface fate and transport. Although difficult even in simple systems, this task grows increasingly complicated for constituents, like Pu, that exhibit complex environmental chemistries. The environmental behavior of Pu can be influenced by complexation, precipitation, adsorption, colloid formation, and oxidation/reduction (redox) reactions (1-3). To predict the environmental mobility of Pu, the most important of these factors is Pu oxidation state. This is because Pu(IV) is generally 2 to 3 orders of magnitude less mobile than Pu(V) in most environments (4). Further complicating matters, Pu commonly exists simultaneously in several oxidation states (5, 6). Choppin (7) reported Pu may exist as Pu(IV), Pu(V), or Pu(VI) oxic natural groundwaters. It is generally accepted that plutonium associated with suspended particulate matter is predominantly Pu(IV) (8-10), whereas Pu in the aqueous phase is predominantly Pu(V) (2, 11-13). The influence of the character of Mn-containing minerals expected to be found in subsurface repository environments on Pu oxidation state distributions has been the subject of much recent research. Kenney-Kennicutt and Morse (14), Duff et al. (15), and Morgenstern and Choppin (16) observed oxidation of Pu facilitated by Mn(IV)-bearing minerals. Conversely, Shaughnessy et al. (17) used X-ray Absorption near-edge spectroscopy (XANES) to show reduction of Pu(VI) by hausmannite (Mn{sup II}Mn{sub 2}{sup III}O{sub 4}) and manganite ({gamma}-Mn{sup III}OOH) and Kersting et al., (18) observed reduction of Pu(VI) by pyrolusite (Mn{sup IV}O{sub 2}). In this paper, we attempt to reconcile the apparently conflicting datasets by showing that Mn-bearing minerals can indeed oxidize Pu, however, if the oxidized species remains on the solid phase, the oxidation step competes with the formation of Pu(IV) that becomes the predominant solid phase Pu species with time. The experimental approach we took was to conduct longer term (approximately two years later) oxidation state analyses on the Pu sorbed to Yucca Mountain tuff (initial analysis reported by Duff et al., (15)) and measure the time-dependant changes in the oxidation state distribution of Pu in the presence of the Mn mineral pyrolusite.

  10. New Generation of MoSx Based Solid Lubricant Coatings: Recent Developments and Applications

    SciTech Connect (OSTI)

    Haider, Julfikar; Hashmi, M. S. J.

    2011-01-17

    In recent times, there is a growing interest in applying Molybdenum disulphide (MoS{sub x}) solid lubricant coatings on components to improve the tribological performance (i.e. lower friction coefficient and wear rate). The tribological performance of MoS{sub x} coating is strongly dependent on coating properties and tribological environment. MoS{sub x} coatings are highly successful in certain applications such as in space/vacuum technology, but its effectiveness is questioned in other terrestrial applications such as in cutting tool industry due to its lower hardness and poor oxidation resistance leading to shorter life. In order to circumvent this drawback, the paper identifies that current research is being concentrated on developing MoS{sub x} based coatings using three different approaches: (1) Metal or compound addition in MoS{sub x} coating (2)MoS{sub x} layer on hard coating and (3)MoS{sub x} addition in hard coating matrix. Although the primary objective is same in all three cases, the third approach is considered to be more effective in improving the tribological properties of the coating. Finally, the potential applications of MoS{sub x} based coatings in different industrial sectors have been briefly outlined.

  11. Photo-oxidation method using MoS2 nanocluster materials

    DOE Patents [OSTI]

    Wilcoxon, Jess P. (Albuquerque, NM)

    2001-01-01

    A method of photo-oxidizing a hydrocarbon compound is provided by dispersing MoS.sub.2 nanoclusters in a solvent containing a hydrocarbon compound contaminant to form a stable solution mixture and irradiating the mixture to photo-oxide the hydrocarbon compound. Hydrocarbon compounds of interest include aromatic hydrocarbon and chlorinated hydrocarbons. MoS.sub.2 nanoclusters with an average diameter less than approximately 10 nanometers are shown to be effective in decomposing potentially toxic aromatic and chlorinated hydrocarbons, such as phenol, pentachlorophenol, chlorinated biphenols, and chloroform, into relatively non-toxic compounds. The irradiation can occur by exposing the MoS.sub.2 nanoclusters and hydrocarbon compound mixture with visible light. The MoS.sub.2 nanoclusters can be introduced to the toxic hydrocarbons as either a MoS.sub.2 solution or deposited on a support material.

  12. Synthesis and characterization of model MgO supported catalyst with Pt-Mo interactions.

    SciTech Connect (OSTI)

    Alexeev, O.; Kawi, S.; Gates, B.C. [Univ. of California, Davis, CA (United States)] [Univ. of California, Davis, CA (United States); Shelef, M. [Ford Motor Co., Dearborn, MI (United States)] [Ford Motor Co., Dearborn, MI (United States)

    1996-01-04

    MgO supported platinum and platinum-molybdenum catalysts were prepared from organometallic precursors and charaterized structurally to determine how the nature of the bimetallic precursors and the treatment conditions affected the interaction between the two metals. Samples were prepared from [PtCl{sub 2}(PhCN){sub 2}], [PtCl{sub 2}(PhCN){sub 2}] + [Mo(CO){sub 6}], and [C@Pt[Mo(CO){sub 3}(C{sub 5}H{sub 5})]{sub 2}(PhCN){sub 2}] BC@ characterized by infrared and extended X-ray absorption fine structure (EXAFS) spectroscopies, tranmission electron microscopy, and chemisorption of H{sub 2}, CO, and O{sub 2}. The samples were treated in H{sub 2} at 400{degree}C prior to most of the characterizatons. Incorporation of Mo reduced the chemisorption of CO and of H{sub 2}. EXAFS spectra measured at the Pt L{sub III} edge and at the Mo K edge showed substantial Pt-Mo contributions with a Pt-Mo cordination number of about 2 and an average distance of 2.63 A for the sample prepared from [C@Pt[Mo(CO){sub 3}(C{sub 5}H{sub 5})]{sub 2}(PhCN){sub 2}] BC@. In constract, no significant Pt-Mo contribution was observed for the sample prepared from [PtCl{sub 2}(PhCN){sub 2}]+ [Mo(CO){sub 6}]. Electron micrographs and EXAFS results show that interaction between Pt and Mo ions in the former sample helped to maintain the platinum in a highly dispersed form, with supported platinum clusters being smaller than about 10 A. 53 refs., 9 figs., 9 tabs.

  13. No X-rays from the very nearby type Ia SN 2014J: Constraints on its environment

    SciTech Connect (OSTI)

    Margutti, R.; Parrent, J.; Kamble, A.; Soderberg, A. M.; Milisavljevic, D.; Drout, M. R.; Kirshner, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Foley, R. J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States)

    2014-07-20

    Deep X-ray observations of the post-explosion environment around the very nearby Type Ia SN 2014J (d{sub L} = 3.5 Mpc) reveal no X-ray emission down to a luminosity L{sub x} < 7 10{sup 36} erg s{sup 1} (0.3-10 keV) at ?t ? 20 days after the explosion. We interpret this limit in the context of inverse Compton emission from upscattered optical photons by the supernova shock and constrain the pre-explosion mass-loss rate of the stellar progenitor system to be M-dot <10{sup ?9} M{sub ?} yr{sup ?1} (for wind velocity v{sub w} = 100 km s{sup 1}). Alternatively, the SN shock might be expanding into a uniform medium with density n{sub CSM} < 3 cm{sup 3}. These results rule out single-degenerate (SD) systems with steady mass loss until the terminal explosion and constrain the fraction of transferred material lost at the outer Lagrangian point to be ?1%. The allowed progenitors are (1) white dwarf-white dwarf progenitors, (2) SD systems with unstable hydrogen burning experiencing recurrent nova eruptions with recurrence time t < 300 yr, and (3) stars where the mass loss ceases before the explosion.

  14. Magnetostructural phase transformations in Tb 1-x Mn 2

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

    Zou, Junding; Paudyal, Durga; Liu, Jing; Mudryk, Yaroslav; Pecharsky, Vitalij K.; Gschneidner, Karl A.

    2015-01-16

    Magnetism and phase transformations in non-stoichiometric Tb1-xMn2 (x = 0.056, 0.039) have been studied as functions of temperature and magnetic field using magnetization, heat capacity, and X-ray powder diffraction measurements. Lowering the temperature, the compounds sequentially order ferrimagnetically and antiferromagnetically, and finally, exhibit spin reorientation transitions. Moreover, these structural distortions from room temperature cubic to low temperature rhombohedral structures occur at TN, and are accompanied by large volume changes reaching ~-1.27% and -1.42%, respectively. First principles electronic structure calculations confirm the phase transformation from the ferrimagnetic cubic structure to the antiferromagnetic rhombohedral structure in TbMn2.

  15. ASYMMETRY IN THE OBSERVED METAL-RICH EJECTA OF THE GALACTIC TYPE IA SUPERNOVA REMNANT G299.22.9

    SciTech Connect (OSTI)

    Post, Seth; Park, Sangwook [Department of Physics, University of Texas at Arlington, Arlington, Box 19059, TX 76019 (United States); Badenes, Carles [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT-PACC), University of Pittsburgh, 3941 OHara Street, Pittsburgh, PA 15260 (United States); Burrows, David N. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Hughes, John P. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States); Lee, Jae-Joon [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Mori, Koji [Department of Applied Physics, University of Miyazaki, 1-1 Gakuen Kibana-dai Nishi, Miyazaki 889-2192 (Japan); Slane, Patrick O., E-mail: seth.post@mavs.uta.edu, E-mail: badenes@pitt.edu, E-mail: burrows@astro.psu.edu, E-mail: jph@physics.rutgers.edu, E-mail: mori@astro.miyazaki-u.ac.jp, E-mail: slane@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2014-09-01

    We have performed a deep Chandra observation of the Galactic TypeIa supernova remnant G299.22.9. Here we report the initial results from our imaging and spectral analysis. The observed abundance ratios of the central ejecta are in good agreement with those predicted by delayed-detonation TypeIa supernovae models. We reveal inhomogeneous spatial and spectral structures of metal-rich ejecta in G299.22.9. The Fe/Si abundance ratio in the northern part of the central ejecta region is higher than that in the southern part. A significant continuous elongation of ejecta material extends out to the western outermost boundary of the remnant. In this western elongation, both the Si and Fe are enriched with a similar abundance ratio to that in the southern part of the central ejecta region. These structured distributions of metal-rich ejecta material suggest that this TypeIa supernova might have undergone a significantly asymmetric explosion and/or has been expanding into a structured medium.

  16. On the state of Mn impurity implanted in Si

    SciTech Connect (OSTI)

    Orlov, A. F.; Bublik, V. T.; Vdovin, V. I.; Agafonov, Yu. A.; Balagurov, L. A.; Zinenko, V. I.; Kulemanov, I. V.; Shcherbachev, K. D.

    2009-07-15

    The state of manganese impurity in implanted silicon at implantation doses of up to 5 x 10{sup 16} cm{sup -2} has been investigated by X-ray diffraction and transmission electron microscopy. It is established that, after short-term vacuum annealing at 850{sup o}C, most of the implanted manganese impurities are in microinclusions up to 20 nm in size formed by a tetragonal silicide phase of the Mn{sub 15}Si{sub 26} type.

  17. Ferromagnetic interactions and martensitic transformation in Fe doped Ni-Mn-In shape memory alloys

    SciTech Connect (OSTI)

    Lobo, D. N.; Priolkar, K. R.; Emura, S.; Nigam, A. K.

    2014-11-14

    The structure, magnetic, and martensitic properties of Fe doped Ni-Mn-In magnetic shape memory alloys have been studied by differential scanning calorimetry, magnetization, resistivity, X-ray diffraction (XRD), and EXAFS. While Ni{sub 2}MnIn{sub 1?x}Fe{sub x} (0???x???0.6) alloys are ferromagnetic and non martensitic, the martensitic transformation temperature in Ni{sub 2}Mn{sub 1.5}In{sub 1?y}Fe{sub y} and Ni{sub 2}Mn{sub 1.6}In{sub 1?y}Fe{sub y} increases for lower Fe concentrations (y???0.05) before decreasing sharply for higher Fe concentrations. XRD analysis reveals presence of cubic and tetragonal structural phases in Ni{sub 2}MnIn{sub 1?x}Fe{sub x} at room temperature with tetragonal phase content increasing with Fe doping. Even though the local structure around Mn and Ni in these Fe doped alloys is similar to martensitic Mn rich Ni-Mn-In alloys, presence of ferromagnetic interactions and structural disorder induced by Fe affect Mn-Ni-Mn antiferromagnetic interactions resulting in suppression of martensitic transformation in these Fe doped alloys.

  18. Manganese valence and coordination structure in Mn,Mg-codoped {gamma}-AlON green phosphor

    SciTech Connect (OSTI)

    Takeda, Takashi; Xie, Rong-Jun; Hirosaki, Naoto; Matsushita, Yoshitaka; Honma, Tetuso

    2012-10-15

    The valence and coordination structure of manganese in a Mn,Mg-codoped {gamma}-AlON spinel-type oxynitride green phosphor were studied by synchrotron X-ray diffraction and absorption fine structure measurements. The absorption edge position of the XANES revealed the bivalency of Mn. Two cation sites are available in the spinel structure for cation doping: a tetrahedral site and an octahedral site. The pre-edge of the XANES and the distance to the nearest neighbor atoms obtained from the EXAFS measurement showed that Mn was situated at the tetrahedral site. Rietveld analysis showed that the vacancy occupied the octahedral site. The preferential occupation of the tetrahedral site by Mn and the roles of N and Mg are discussed in relation to the spinel crystal structure. - Graphical Abstract: Fourier transform of EXAFS of Mn K-edge for Mn,Mg-codoped green phosphor and Mn coordination structure. Highlights: Black-Right-Pointing-Pointer Mn, Mg-codoped {gamma}-AlON green phosphor for white LED. Black-Right-Pointing-Pointer The valence of Mn is divalent. Black-Right-Pointing-Pointer Mn occupies the tetrahedral site in the spinel structure.

  19. Effect of composition and heat treatment on MnBi magnetic materials

    SciTech Connect (OSTI)

    Cui, Jun [Pacific Northwest National Laboratory; Choi, Jung-Pyung [Pacific Northwest National Laboratory; Polikarpov, Evgueni [Pacific Northwest National Laboratory; Bowden, Mark E [Pacific Northwest National Laboratory; Xie, Wei [Pacific Northwest National Laboratory; Li, Guosheng [Pacific Northwest National Laboratory; Nie, Zimin [Pacific Northwest National Laboratory; Zarkevich, Nikolai [Ames Laboratory; Kramer, Matthew J [Ames Laboratory; Johnson, Duane [Ames Laboratory

    2014-10-01

    The metallic compound MnBi is a promising rare-earth-free permanent magnet material, unique among all candidates for its high intrinsic coercivity (Hci) and its large positive temperature coefficient. The Hci of MnBi in thin-film or powder form can exceed 12 and 26 kOe at 300 and 523 K, respectively. Such a steep rise in Hci with increasing temperature is unique to MnBi. Consequently, MnBi is a highly sought-after hard phase for exchange coupling nanocomposite magnets. However, the reaction between Mn and Bi is peritectic, and hence Mn tends to precipitate out of the MnBi liquid during the solidification process. As result, when the alloy is prepared using conventional induction or arc-melting casting methods, additional Mn is required to compensate the precipitation of Mn. In addition to composition, post-casting annealing plays an important role in obtaining a high content of MnBi low-temperature phase (LTP) because the annealing encourages the Mn precipitates and the unreacted Bi to react, forming the desired LTP phase. Here we report a systematic study of the effect of composition and heat treatments on the phase content and magnetic properties of MnBi alloys. In this study, 14 compositions were prepared using conventional metallurgical methods, and the compositions, crystal structures, phase content and magnetic properties of the resulting alloys were analyzed. The results show that the composition with 55 at.% Mn exhibits both the highest LTP content (93 wt.%) and magnetization (74 emu g?1 with 9 T applied field at 300 K).

  20. Large exchange bias enhancement in (Pt(or Pd)/Co)/IrMn/Co trilayers with ultrathin IrMn thanks to interfacial Cu dusting

    SciTech Connect (OSTI)

    Vinai, G. [SPINTEC, UMR 8191 CEA/CNRS/UJF/Grenoble-INP, CEA/INAC, 17, rue des Martyrs, 38054 Grenoble (France); Crocus Technology, 4 Place Robert Schuman, 38054 Grenoble (France); Moritz, J. [Institut Jean Lamour, UMR 7198 CNRS - Universit de Lorraine, Bd des Aiguillettes, BP 70239, F-54506 Vandoeuvre-les-Nancy Cedex (France); Bandiera, S. [Crocus Technology, 4 Place Robert Schuman, 38054 Grenoble (France); Prejbeanu, I. L.; Dieny, B. [SPINTEC, UMR 8191 CEA/CNRS/UJF/Grenoble-INP, CEA/INAC, 17, rue des Martyrs, 38054 Grenoble (France)

    2014-04-21

    The magnitude of exchange bias (H{sub ex}) at room temperature can be significantly enhanced in IrMn/Co and (Pt(or Pd)/Co)/IrMn/Co structures thanks to the insertion of an ultrathin Cu dusting layer at the IrMn/Co interface. The combination of trilayer structure and interfacial Cu dusting leads to a three-fold increase in H{sub ex} as compared to the conventional IrMn/Co bilayer structure, with an increased blocking temperature (T{sub B}) and a concave curvature of the temperature dependence H{sub ex}(T), ideal for improved Thermally Assisted-Magnetic Random Access Memory storage layer. This exchange bias enhancement is ascribed to a reduction of the spin frustration at the IrMn/Co interface thanks to interfacial Cu addition.

  1. Surface Structures of Cubo-octahedral Pt-Mo Catalyst Nanoparticles from Monte Carlo Simulations

    SciTech Connect (OSTI)

    Wang, Guofeng; Van Hove, M.A.; Ross, P.N.; Baskes, M.I.

    2005-03-31

    The surface structures of cubo-octahedral Pt-Mo nanoparticles have been investigated using the Monte Carlo method and modified embedded atom method potentials that we developed for Pt-Mo alloys. The cubo-octahedral Pt-Mo nanoparticles are constructed with disordered fcc configurations, with sizes from 2.5 to 5.0 nm, and with Pt concentrations from 60 to 90 at. percent. The equilibrium Pt-Mo nanoparticle configurations were generated through Monte Carlo simulations allowing both atomic displacements and element exchanges at 600 K. We predict that the Pt atoms weakly segregate to the surfaces of such nanoparticles. The Pt concentrations in the surface are calculated to be 5 to 14 at. percent higher than the Pt concentrations of the nanoparticles. Moreover, the Pt atoms preferentially segregate to the facet sites of the surface, while the Pt and Mo atoms tend to alternate along the edges and vertices of these nanoparticles. We found that decreasing the size or increasing the Pt concentration leads to higher Pt concentrations but fewer Pt-Mo pairs in the Pt-Mo nanoparticle surfaces.

  2. Distributed Production of Radionuclide Mo-99 Charles A. Gentile, Adam B.

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

    Cohen and George Ascione | Princeton Plasma Physics Lab Distributed Production of Radionuclide Mo-99 Charles A. Gentile, Adam B. Cohen and George Ascione This invention is for the production of Technetium-99m (Tc-99m), a widely used medical isotope in a distributed and in-situ fashion. Tc-99m results when Molybdenum 99 (Mo-99) decays. Mo-99 is typically produced in a nuclear reactor, but it can be produced from naturally occurring Molybdenum 100 or from Molybdenum 98 using either neutrons or

  3. Unoccupied electronic structure of Ni2MnGa ferromagnetic shape memory alloy

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Unoccupied electronic structure of Ni2MnGa ferromagnetic shape memory alloy Citation Details In-Document Search This content will become publicly available on August 20, 2016 Title: Unoccupied electronic structure of Ni2MnGa ferromagnetic shape memory alloy Momentum resolved inverse photoemission spectroscopy measurements show that the dispersion of the unoccupied bands of Ni2MnGa is significant in the austenite phase. Furthermore, in the martensite phase,

  4. Structural and ferromagnetic properties of an orthorhombic phase of MnBi stabilized with Rh additions

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

    Taufour, Valentin; Thimmaiah, Srinivasa; March, Stephen; Saunders, Scott; Sun, Kewei; Lamichhane, Tej Nath; Kramer, Matthew J.; Bud’ko, Sergey L.; Canfield, Paul C.

    2015-07-28

    The article addresses the possibility of alloy elements in MnBi which may modify the thermodynamic stability of the NiAs-type structure without significantly degrading the magnetic properties. The addition of small amounts of Rh and Mn provides an improvement in the thermal stability with some degradation of the magnetic properties. The small amounts of Rh and Mn additions in MnBi stabilize an orthorhombic phase whose structural and magnetic properties are closely related to the ones of the previously reported high-temperature phase of MnBi (HT MnBi). The properties of the HT MnBi, which is stable between 613 and 719 K, have notmore » been studied in detail because of its transformation to the stable low-temperature MnBi (LT MnBi), making measurements near and below its Curie temperature difficult. The Rh-stabilized MnBi with chemical formula Mn1.0625–xRhxBi [x=0.02(1)] adopts a new superstructure of the NiAs/Ni2In structure family. It is ferromagnetic below a Curie temperature of 416 K. The critical exponents of the ferromagnetic transition are not of the mean-field type but are closer to those associated with the Ising model in three dimensions. The magnetic anisotropy is uniaxial; the anisotropy energy is rather large, and it does not increase when raising the temperature, contrary to what happens in LT MnBi. The saturation magnetization is approximately 3μB/f.u. at low temperatures. Thus, while this exact composition may not be application ready, it does show that alloying is a viable route to modifying the stability of this class of rare-earth-free magnet alloys.« less

  5. Cr(OH)?(s) Oxidation Induced by Surface Catalyzed Mn(II) Oxidation

    SciTech Connect (OSTI)

    Namgung, Seonyi; Kwon, M.; Qafoku, Nikolla; Lee, Gie Hyeon

    2014-09-16

    This study examined the feasibility of Cr(OH)?(s) oxidation mediated by surface catalyzed Mn(II) oxidation under common groundwater pH conditions as a potential pathway of natural Cr(VI) contaminations. Dissolved Mn(II) (50 ?M) was reacted with or without synthesized Cr(OH)?(s) (1.0 g/L) at pH 7 9 under oxic or anoxic conditions. In the absence of Cr(OH)?(s), homogeneous Mn(II) oxidation by dissolved O? was not observed at pH ? 8.0 for 50 d. At pH 9.0, by contrast, dissolved Mn(II) was completely removed within 8 d and precipitated as hausmannite. When Cr(OH)?(s) was present, this solid was oxidized and released substantial amounts of Cr(VI) as dissolved Mn(II) was added into the suspension at pH ? 8.0 under oxic conditions. Our results suggest that Cr(OH)?(s) was readily oxidized by a newly formed Mn oxide as a result of Mn(II) oxidation catalyzed on Cr(OH)?(s) surface. XANES analysis of the residual solids after the reaction between 1.0 g/L Cr(OH)?(s) and 204 ?M Mn(II) at pH 9.0 for 22 d revealed that the product of surface catalyzed Mn(II) oxidation resembled birnessite. The rate and extent of Cr(OH)?(s) oxidation was likely controlled by those of surface catalyzed Mn(II) oxidation as the production of Cr(VI) increased with increasing pH and initial Mn(II) concentrations. This study evokes the potential environmental hazard of sparingly soluble Cr(OH)?(s) that can be a source of Cr(VI) in the presence of dissolved Mn(II).

  6. Enhanced magnetic hysteresis in Ni-Mn-Ga single crystal and its influence

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

    on magnetic shape memory effect (Journal Article) | SciTech Connect Enhanced magnetic hysteresis in Ni-Mn-Ga single crystal and its influence on magnetic shape memory effect Citation Details In-Document Search Title: Enhanced magnetic hysteresis in Ni-Mn-Ga single crystal and its influence on magnetic shape memory effect Enhanced magnetic hysteresis due to boron doping in combination with magnetic shape memory effect in Ni-Mn-Ga single crystal results in new interesting functionality of

  7. Electronic Structure and Oxidation State Changes in the Mn (4) Ca Cluster of Photosystem II

    SciTech Connect (OSTI)

    Yano, J.; Pushkar, Y.; Messinger, J.; Bergmann, U.; Glatzel, P.; Yachandra, V.K.; /SLAC

    2012-08-17

    Oxygen-evolving complex (Mn{sub 4}Ca cluster) of Photosystem II cycles through five intermediate states (S{sub i}-states, i = 0-4) before a molecule of dioxygen is released. During the S-state transitions, electrons are extracted from the OEC, either from Mn or alternatively from a Mn ligand. The oxidation state of Mn is widely accepted as Mn{sub 4}(III{sub 2},IV{sub 2}) and Mn{sub 4}(III,IV{sub 3}) for S{sub 1} and S{sub 2} states, while it is still controversial for the S{sub 0} and S{sub 3} states. We used resonant inelastic X-ray scattering (RIXS) to study the electronic structure of Mn{sub 4}Ca complex in the OEC. The RIXS data yield two-dimensional plots that provide a significant advantage by obtaining both K-edge pre-edge and L-edge-like spectra (metal spin state) simultaneously. We have collected data from PSII samples in the each of the S-states and compared them with data from various inorganic Mn complexes. The spectral changes in the Mn 1s2p{sub 3/2} RIXS spectra between the S-states were compared to those of the oxides of Mn and coordination complexes. The results indicate strong covalency for the electronic configuration in the OEC, and we conclude that the electron is transferred from a strongly delocalized orbital, compared to those in Mn oxides or coordination complexes. The magnitude for the S{sub 0} to S{sub 1}, and S{sub 1} to S{sub 2} transitions is twice as large as that during the S{sub 2} to S{sub 3} transition, indicating that the electron for this transition is extracted from a highly delocalized orbital with little change in charge density at the Mn atoms.

  8. Enhanced magnetic hysteresis in Ni-Mn-Ga single crystal and its...

    Office of Scientific and Technical Information (OSTI)

    shape memory effect Citation Details In-Document Search Title: Enhanced magnetic hysteresis in Ni-Mn-Ga single crystal and its influence on magnetic shape memory effect ...

  9. CaMn2Sb2: Spin waves on a frustrated antiferromagnetic honeycomb lattice

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect CaMn2Sb2: Spin waves on a frustrated antiferromagnetic honeycomb lattice Citation Details In-Document Search This content will become publicly available on May 22, 2016 Title: CaMn2Sb2: Spin waves on a frustrated antiferromagnetic honeycomb lattice We present inelastic neutron scattering measurements of the antiferromagnetic insulator CaMn2Sb2:, which consists of corrugated honeycomb layers of Mn. The dispersion of magnetic excitations has been measured

  10. Preparation and electrochemical properties of lamellar MnO{sub 2} for supercapacitors

    SciTech Connect (OSTI)

    Yan, Jun; Wei, Tong; Cheng, Jie; Fan, Zhuangjun; Zhang, Milin

    2010-02-15

    Lamellar birnessite-type MnO{sub 2} materials were prepared by changing the pH of the initial reaction system via hydrothermal synthesis. The interlayer spacing of MnO{sub 2} with a layered structure increased gradually when the initial pH value varied from 12.43 to 2.81, while the MnO{sub 2}, composed of {alpha}-MnO{sub 2} and {gamma}-MnO{sub 2}, had a rod-like structure at pH 0.63. Electrochemical studies indicated that the specific capacitance of birnessite-type MnO{sub 2} was much higher than that of rod-like MnO{sub 2} at high discharge current densities due to the lamellar structure with fast intercalation/deintercalation of protons and high utilization of MnO{sub 2}. The initial specific capacitance of MnO{sub 2} prepared at pH 2.81 was 242.1 F g{sup -1} at 2 mA cm{sup -2} in 2 mol L{sup -1} (NH{sub 4}){sub 2}SO{sub 4} aqueous electrolyte. The capacitance increased by about 8.1% of initial capacitance after 200 cycles at a current density of 100 mA cm{sup -2}.

  11. Monolayers of MoS{sub 2} as an oxidation protective nanocoating material

    SciTech Connect (OSTI)

    Sen, H. Sener; Sahin, H.; Peeters, F. M.; Durgun, E.

    2014-08-28

    First-principle calculations are employed to investigate the interaction of oxygen with ideal and defective MoS{sub 2} monolayers. Our calculations show that while oxygen atoms are strongly bound on top of sulfur atoms, the oxygen molecule only weakly interacts with the surface. The penetration of oxygen atoms and molecules through a defect-free MoS{sub 2} monolayer is prevented by a very high diffusion barrier indicating that MoS{sub 2} can serve as a protective layer for oxidation. The analysis is extended to WS{sub 2} and similar coating characteristics are obtained. Our calculations indicate that ideal and continuous MoS{sub 2} and WS{sub 2} monolayers can improve the oxidation and corrosion-resistance of the covered surface and can be considered as an efficient nanocoating material.

  12. Microscopic origin of low frequency noise in MoS{sub 2} field-effect transistors

    SciTech Connect (OSTI)

    Ghatak, Subhamoy; Jain, Manish; Ghosh, Arindam; Mukherjee, Sumanta; Sarma, D. D.

    2014-09-01

    We report measurement of low frequency 1/f noise in molybdenum di-sulphide (MoS{sub 2}) field-effect transistors in multiple device configurations including MoS{sub 2} on silicon dioxide as well as MoS{sub 2}-hexagonal boron nitride (hBN) heterostructures. All as-fabricated devices show similar magnitude of noise with number fluctuation as the dominant mechanism at high temperatures and density, although the calculated density of traps is two orders of magnitude higher than that at the SiO{sub 2} interface. Measurements on the heterostructure devices with vacuum annealing and dual gated configuration reveals that along with the channel, metal-MoS{sub 2} contacts also play a significant role in determining noise magnitude in these devices.

  13. File:USDA-CE-Production-GIFmaps-MO.pdf | Open Energy Information

    Open Energy Info (EERE)

    MO.pdf Jump to: navigation, search File File history File usage Missouri Ethanol Plant Locations Size of this preview: 776 600 pixels. Full resolution (1,650 1,275 pixels,...

  14. Substrate interactions with suspended and supported monolayer MoS2: Angle-resolved photoemission spectroscopy

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

    Jin, Wencan; Yeh, Po -Chun; Zaki, Nader; Zhang, Datong; Liou, Jonathan T.; Dadap, Jerry I.; Barinov, Alexey; Yablonskikh, Mikhail; Sadowski, Jerzy T.; Sutter, Peter; et al

    2015-03-17

    We report the directly measured electronic structure of exfoliated monolayer molybdenum disulfide (MoS₂) using micrometer-scale angle-resolved photoemission spectroscopy. Measurements of both suspended and supported monolayer MoS₂ elucidate the effects of interaction with a substrate. Thus, a suggested relaxation of the in-plane lattice constant is found for both suspended and supported monolayer MoS₂ crystals. For suspended MoS₂, a careful investigation of the measured uppermost valence band gives an effective mass at Γ¯ and Κ¯ of 2.00m₀ and 0.43m₀, respectively. We also measure an increase in the band linewidth from the midpoint of Γ¯Κ¯ to the vicinity of Κ¯ and briefly discussmore » its possible origin.« less

  15. DE-EM-0001971 WIPP M&O J-8 PART III - LIST OF DOCUMENTS, EXHIBITS...

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

    8 PART III - LIST OF DOCUMENTS, EXHIBITS AND OTHER ATTACHMENTS SECTION J ATTACHMENT C: DRAFT PERFORMANCE EVALUATION AND MEASUREMENT PLAN (PEMP) DE-EM-0001971 WIPP M&O J-9 Draft...

  16. Electrochemical Testing of Ni-Cr-Mo-Gd Alloys

    SciTech Connect (OSTI)

    T. E. Lister; R. E. Mizia; H. Tian

    2005-10-01

    The waste package site recommendation design specified a boron-containing stainless steel, Neutronit 976/978, for fabrication of the internal baskets that will be used as a corrosion-resistant neutron-absorbing material. Recent corrosion test results gave higher-than-expected corrosion rates for this material. The material callout for these components has been changed to a Ni-Cr-Mo-Gd alloy (ASTM-B 932-04, UNS N06464) that is being developed at the Idaho National Laboratory. This report discusses the results of initial corrosion testing of this material in simulated in-package environments that could contact the fuel baskets after breach of the waste package outer barrier. The corrosion test matrix was executed using the potentiodynamic and potentiostatic electrochemical test techniques. The alloy performance shows low rates of general corrosion after initial removal of a gadolinium-rich second phase that intersects the surface. The high halide-containing test solutions exhibited greater tendencies toward initiation of crevice corrosion.

  17. Thermo-physical Properties of DU-10 wt.% Mo Alloys

    SciTech Connect (OSTI)

    Douglas E. Burkes; Cynthia A. Papesch; Andrew P. Maddison; Thomas Hartmann; Francine J. Rice

    2010-08-01

    Low-enriched uranium alloyed with 10 wt% molybdenum is under consideration by the Global Threat Reduction Initiative reactor convert program as a very high density fuel to enable the conversion of high-performance research reactors away from highly-enriched uranium fuels. As with any fuel development program, the thermophysical properties of the fuel as a function of temperature are extremely important and must be well characterized in order to effectively model and predict fuel behavior under normal and off-normal irradiation conditions. For the alloy system under investigation, there is a lack of thermophysical property data, and in most cases, the data is relatively inconsistent and lacks sufficient explanation. Available literature on this alloy system comes mainly from studies done during the 1960s and 1970s, and often does not include sufficient information on fabrication history or conditions to draw conclusions for the current application. The current paper has investigated specific heat capacity, coefficient of linear thermal expansion, density, and thermal diffusivity that were then used to calculate alloy thermal conductivity as a function of temperature. The data obtained from this investigation was compared to available literature on similar U-Mo alloys, and in most cases are in good agreement.

  18. Rotationally Commensurate Growth of MoS[subscript 2] on Epitaxial Graphene

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Rotationally Commensurate Growth of MoS[subscript 2] on Epitaxial Graphene Citation Details In-Document Search Title: Rotationally Commensurate Growth of MoS[subscript 2] on Epitaxial Graphene Authors: Liu, Xiaolong ; Balla, Itamar ; Bergeron, Hadallia ; Campbell, Gavin P. ; Bedzyk, Michael J. ; Hersam, Mark C. [1] + Show Author Affiliations NWU Publication Date: 2016-03-04 OSTI Identifier: 1240188 Resource

  19. Demonstration of LED Street Lighting in Kansas City, MO (Technical Report)

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

    | SciTech Connect Demonstration of LED Street Lighting in Kansas City, MO Citation Details In-Document Search Title: Demonstration of LED Street Lighting in Kansas City, MO Nine different streetlighting products were installed on various streets in Kansas City, Missouri during February, 2011, to evaluate their performance relative to the incumbent high-pressure sodium (HPS) lighting. The applications investigated included 100 W, 150 W, 250 W, and 400 W HPS installations. Initial measurements

  20. DOE - Office of Legacy Management -- Weldon Spring Chemical Co - MO 03

    Office of Legacy Management (LM)

    Weldon Spring Chemical Co - MO 03 FUSRAP Considered Sites Site: Weldon Spring Chemical Co. (MO.03) Designated Name: Alternate Name: Location: Evaluation Year: Site Operations: Site Disposition: Radioactive Materials Handled: Primary Radioactive Materials Handled: Radiological Survey(s): Site Status: Also see Weldon Spring, Missouri, Site Documents Related to Weldon Spring Chemical Co. Summary of Work Session - Focus Area: Monitoring and Maintenance. Summary of Weldon Spring Long-Term Stewardship

  1. International Falls, MN Natural Gas Pipeline Imports From Canada (Dollars

    U.S. Energy Information Administration (EIA) Indexed Site

    per Thousand Cubic Feet) Dollars per Thousand Cubic Feet) International Falls, MN Natural Gas Pipeline Imports From Canada (Dollars per Thousand Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9 1990's 1.71 2.03 2.00 2.33 2000's 2.77 4.85 3.01 -- -- 11.20 -- - = No Data Reported; -- = Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data. Release Date: 2/29/2016 Next Release Date: 3/31/2016 Referring Pages: U.S.

  2. International Falls, MN Natural Gas Pipeline Imports From Canada (Million

    U.S. Energy Information Administration (EIA) Indexed Site

    Cubic Feet) Million Cubic Feet) International Falls, MN Natural Gas Pipeline Imports From Canada (Million Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9 1990's 6,373 6,544 6,103 4,857 2000's 3,022 617 602 0 0 22 0 - = No Data Reported; -- = Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data. Release Date: 2/29/2016 Next Release Date: 3/31/2016 Referring Pages: U.S.

  3. Unoccupied electronic states of icosahedral Al-Pd-Mn quasicrystals:

    Office of Scientific and Technical Information (OSTI)

    Evidence of image potential resonance and pseudogap (Journal Article) | SciTech Connect We study the unoccupied region of the electronic structure of the fivefold symmetric surface of an icosahedral (i) Al-Pd-Mn quasicrystal. A feature that exhibits parabolic dispersion with an effective mass of (1.15±0.1)me and tracks the change in the work function is assigned to an image potential resonance because our density functional calculation shows an absence of band gap in the respective energy

  4. High reflectance and low stress Mo2C/Be multilayers

    DOE Patents [OSTI]

    Bajt, Sasa (Livermore, CA); Barbee, Jr., Troy W. (Palo Alto, CA)

    2001-01-01

    A material for extreme ultraviolet (EUV) multilayers that will reflect at about 11.3 nm, have a high reflectance, low stress, and high thermal and radiation stability. The material consists of alternating layers of Mo.sub.2 C and Be deposited by DC magnetron sputtering on a substrate, such as silicon. In one example a Mo.sub.2 C/Be multilayer gave 65.2% reflectance at 11.25 nm measured at 5 degrees off normal incidence angle, and consisted of 70 bilayers with a deposition period of 5.78 nm, and was deposited at 0.83 mTorr argon (Ar) sputtering pressure, with the first and last layers being Be. The stress of the multilayer is tensile and only +88 MPa, compared to +330 MPa of a Mo/Be multilayers of the same thickness. The Mo.sub.2 C/Be multilayer was capped with carbon which produced an increase in reflectivity of about 7% over a similar multilayer with no carbon capping material, thus raising the reflectivity from 58.3% to over 65%. The multilayers were formed using either Mo.sub.2 C or Be as the first and last layers, and initial testing has shown the formation of beryllium carbide at the interfaces between the layers which both stabilizes and has a smoothing effect, and appear to be smoother than the interfaces in Mo/Be multilayers.

  5. Stability of precipitate phases in Fe-rich Fe-Cr-Ni-Mo alloys

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

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T

    2015-01-01

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the and phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. Two key findings resulted from this work. One is that the phase is stable at high temperature and transformed into the phase at lowmoretemperature. The other is that both the and phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.less

  6. Thermal stability of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-06-12

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the chi and Laves phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 °C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed into the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.

  7. Thermal stability of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys

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

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-06-12

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the chi and Laves phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 °C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed intomore » the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.« less

  8. Effects of thermal treatment on the co-rolled U-Mo fuel foils

    SciTech Connect (OSTI)

    Dennis D. Keiser, Jr.; Tammy L. Trowbridge; Cynthia R. Breckenridge; Brady L. Mackowiak; Glenn A. Moore; Barry H. Rabin; Mitchell K. Meyer

    2014-11-01

    A monolithic fuel type is being developed to convert US high performance research and test reactors such as Advanced Test Reactor (ATR) at Idaho National Laboratory from highly enriched uranium (HEU) to low-enriched uranium (LEU). The interaction between the cladding and the U-Mo fuel meat during fuel fabrication and irradiation is known to have negative impacts on fuel performance, such as mechanical integrity and dimensional stability. In order to eliminate/minimize the direct interaction between cladding and fuel meat, a thin zirconium diffusion barrier was introduced between the cladding and U-Mo fuel meat through a co-rolling process. A complex interface between the zirconium and U-Mo was developed during the co-rolling process. A predictable interface between zirconium and U-Mo is critical to achieve good fuel performance since the interfaces can be the weakest link in the monolithic fuel system. A post co-rolling annealing treatment is expected to create a well-controlled interface between zirconium and U-Mo. A systematic study utilizing post co-rolling annealing treatment has been carried out. Based on microscopy results, the impacts of the annealing treatment on the interface between zirconium and U-Mo will be presented and an optima annealing treatment schedule will be suggested. The effects of the annealing treatment on the fuel performance will also be discussed.

  9. MoS{sub 2} nanotube exfoliation as new synthesis pathway to molybdenum blue

    SciTech Connect (OSTI)

    Visic, B.; Gunde, M. Klanjsek; Kovac, J.; Iskra, I.; Jelenc, J.; Remskar, M.; Centre of Excellence Namaste, Jamova cesta 39, SI-1000 Ljubljana

    2013-02-15

    Graphical abstract: . Display Omitted Highlights: ? New synthesis approach to obtaining molybdenum blue via exfoliated MoS{sub 2} nanotubes. ? Material is prone to self assembly and is stable in high vacuum. ? Molecules are as small as 2 nm and their clusters are up to tens of nanometers. ? Change in absorption and oxidation states from the precursor MoS{sub 2}. -- Abstract: Molybdenum blue-type materials are usually obtained by partially reducing Mo{sup VI+} in acidic solutions, while in the presented method it is formed in ethanol solution of exfoliated MoS{sub 2} nanotubes, where the MoS{sub 2} flakes are the preferential location for their growth. Material was investigated by means of scanning electron and atomic force microscopy, showing the structure and self assembly, while also confirming that it is stable in high vacuum with molecules as small as 1.6 nm and the agglomerates of few tens of nanometres. The ultravioletvisible and photoelectron spectrometry show the change in absorption properties and oxidation states from MoS{sub 2} structure to molybdenum blue, while the presence of sulphur suggests that this is a new type of molybdenum blue material.

  10. Electrochemical performance studies of MnO{sub 2} nanoflowers recovered from spent battery

    SciTech Connect (OSTI)

    Ali, Gomaa A.M.; Tan, Ling Ling; Jose, Rajan; Yusoff, Mashitah M.; Chong, Kwok Feng

    2014-12-15

    Highlights: MnO{sub 2} is recovered from spent zinccarbon batteries as nanoflowers structure. Recovered MnO{sub 2} nanoflowers show high specific capacitance. Recovered MnO{sub 2} nanoflowers show stable electrochemical cycling up to 900 cycles. Recovered MnO{sub 2} nanoflowers show low resistance in EIS data. - Abstract: The electrochemical performance of MnO{sub 2} nanoflowers recovered from spent household zinccarbon battery is studied by cyclic voltammetry, galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy. MnO{sub 2} nanoflowers are recovered from spent zinccarbon battery by combination of solution leaching and electrowinning techniques. In an effort to utilize recovered MnO{sub 2} nanoflowers as energy storage supercapacitor, it is crucial to understand their structure and electrochemical performance. X-ray diffraction analysis confirms the recovery of MnO{sub 2} in birnessite phase, while electron microscopy analysis shows the MnO{sub 2} is recovered as 3D nanostructure with nanoflower morphology. The recovered MnO{sub 2} nanoflowers exhibit high specific capacitance (294 F g{sup ?1} at 10 mV s{sup ?1}; 208.5 F g{sup ?1} at 0.1 A g{sup ?1}) in 1 M Na{sub 2}SO{sub 4} electrolyte, with stable electrochemical cycling. Electrochemical data analysis reveal the great potential of MnO{sub 2} nanoflowers recovered from spent zinccarbon battery in the development of high performance energy storage supercapacitor system.

  11. Expectations for the hard x-ray continuum and gamma-ray line fluxes from the typE IA supernova SN 2014J in M82

    SciTech Connect (OSTI)

    The, Lih-Sin [Department of Physics and Astronomy, Clemson University, SC 29634 (United States); Burrows, Adam, E-mail: tlihsin@clemson.edu, E-mail: burrows@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2014-05-10

    The hard X-ray continuum and gamma-ray lines from a Type Ia supernova dominate its integrated photon emissions and can provide unique diagnostics of the mass of the ejecta, the {sup 56}Ni yield and spatial distribution, its kinetic energy and expansion speed, and the mechanism of explosion. Such signatures and their time behavior 'X-ray' the bulk debris field in direct fashion, and do not depend on the ofttimes problematic and elaborate UV, optical, and near-infrared spectroscopy and radiative transfer that have informed the study of these events for decades. However, to date no hard photons have ever been detected from a Type Ia supernova in explosion. With the advent of the supernova SN 2014J in M82, at a distance of ?3.5 Mpc, this situation may soon change. Both NuSTAR and INTEGRAL have the potential to detect SN 2014J, and, if spectra and light curves can be measured, would usefully constrain the various explosion models published during the last ?30 yr. In support of these observational campaigns, we provide predictions for the hard X-ray continuum and gamma-line emissions for 15 Type Ia explosion models gleaned from the literature. The model set, containing as it does deflagration, delayed detonation, merger detonation, pulsational delayed detonation, and sub-Chandrasekhar helium detonation models, collectively spans a wide range of properties, and hence signatures. We provide a brief discussion of various diagnostics (with examples), but importantly make the spectral and line results available electronically to aid in the interpretation of the anticipated data.

  12. Type Ia Supernovae

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

    that the universe is undergoing an accelerated expansion - a result which fits the General Relativity if a yet unknown form of "dark" energy is assumed to dominate the...

  13. Gorchakova-IA

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

    Atl anta, Georgia, March 19-23, 2001 1 Estimate of Horizontal Cloud Inhomogeneity Effect on Solar Radiative Fluxes for Conditions of Winter Zvenigorod Experiment I. A. Gorchakova, G. S. Golitsyn, and I. I. Mokhov Oboukhov Institute of Atmospheric Physics Russian Academy of Sciences Moscow, Russia T. B. Zhuravleva Institute of Atmospheric Optics Tomsk, Russia Introduction Study of physical phenomena determining large-scale dynamical and energetic processes in the atmosphere requires quite full

  14. IA News Archive

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Dilma Rousseff of Brazil and he announced the creation of a Strategic Energy Dialogue (SED) to support the two countries' common goals of developing safe, secure and affordable...

  15. IA Blog Archive

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    2014 21:03:00 +0000 921386 at http:energy.gov Ministers Meet in Addis Ababa for U.S.-Africa Energy Ministerial http:energy.goviaarticlesministers-meet-addis-ababa-us-africa-...

  16. Microstructure evolution of Li uptake/removal in MoO{sub 2}@C nanoparticles with high lithium storage performance

    SciTech Connect (OSTI)

    Liu, Yulong; Zhang, Hong; Ouyang, Pan; Chen, Wenhao [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Li, Zhicheng, E-mail: zhchli@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)

    2014-02-01

    Highlights: The carbon-coated MoO{sub 2} (MoO{sub 2}@C) ultra fine nanoparticles are synthesized by one-pot hydrothermal method. MoO{sub 2}@C nanoparticles have high specific capacity, excellent cycling performance and rate performance. Phase transformations for lithium ion uptake/removal are examined carefully by TEM. Phase transformations are highly reversible during the redox process. - Abstract: A facile one pot strategy of a hydrothermal methodology was applied to synthesize the carbon coated MoO{sub 2} (MoO{sub 2}@C) nanostructured particles, which are composed of ultra fine nanoparticles with homogeneous carbon coating about several nanometers. As an electrode in lithium ion batteries, the MoO{sub 2}@C shows a high specific capacity and reversible capacity (730 mA h g{sup ?1} after 60 cycles). Microstructure investigations, by using a high resolution transmission electron microscopy, of the MoO{sub 2}@C based electrodes employed at various states during the first discharge/charge cycle were conducted to elucidate the lithium ion uptake/removal mechanism and cycling behavior. In the lithium uptake process, the original MoO{sub 2} phase transfers into Li{sub 0.98}MoO{sub 2} through an addition type reaction, and then nanosized metallic Mo emerges as a result of a conversion reaction. In turn, Mo could be oxidized to the intermediate Li{sub 0.98}MoO{sub 2} before converting to hyperfine MoO{sub 2} phase on upcoming lithium removal process.

  17. THE EFFECT OF THE PRE-DETONATION STELLAR INTERNAL VELOCITY PROFILE ON THE NUCLEOSYNTHETIC YIELDS IN TYPE Ia SUPERNOVA

    SciTech Connect (OSTI)

    Kim, Yeunjin; Jordan, G. C. IV; Graziani, Carlo; Lamb, D. Q.; Truran, J. W.; Meyer, B. S.

    2013-07-01

    A common model of the explosion mechanism of Type Ia supernovae is based on a delayed detonation of a white dwarf. A variety of models differ primarily in the method by which the deflagration leads to a detonation. A common feature of the models, however, is that all of them involve the propagation of the detonation through a white dwarf that is either expanding or contracting, where the stellar internal velocity profile depends on both time and space. In this work, we investigate the effects of the pre-detonation stellar internal velocity profile and the post-detonation velocity of expansion on the production of {alpha}-particle nuclei, including {sup 56}Ni, which are the primary nuclei produced by the detonation wave. We perform one-dimensional hydrodynamic simulations of the explosion phase of the white dwarf for center and off-center detonations with five different stellar velocity profiles at the onset of the detonation. In order to follow the complex flows and to calculate the nucleosynthetic yields, approximately 10,000 tracer particles were added to every simulation. We observe two distinct post-detonation expansion phases: rarefaction and bulk expansion. Almost all the burning to {sup 56}Ni occurs only in the rarefaction phase, and its expansion timescale is influenced by pre-existing flow structure in the star, in particular by the pre-detonation stellar velocity profile. We find that the mass fractions of the {alpha}-particle nuclei, including {sup 56}Ni, are tight functions of the empirical physical parameter {rho}{sub up}/v{sub down}, where {rho}{sub up} is the mass density immediately upstream of the detonation wave front and v{sub down} is the velocity of the flow immediately downstream of the detonation wave front. We also find that v{sub down} depends on the pre-detonation flow velocity. We conclude that the properties of the pre-existing flow, in particular the internal stellar velocity profile, influence the final isotopic composition of burned matter produced by the detonation.

  18. Lattice Mn3+ Behaviors in Li4Ti5O12/LiNi0.5Mn1.5O4 Full Cells

    SciTech Connect (OSTI)

    Zheng, Jianming; Xiao, Jie; Nie, Zimin; Zhang, Jiguang

    2013-05-28

    High voltage spinels LiNi0.5Mn1.5O4 (LNMO) with different contents of residual Mn3+ ions have been evaluated in full cells using Li4Ti5O12 (LTO) as standard anode. Greatly improved cycling stability has been observed for all spinels in LTO-limited full cell, compared with those in LNMO-limited ones, while the underlying mechanisms are quite different. It has been discovered that the participation of active Mn3+ in the extended cycling and thus its observable contribution to Li+ diffusion kinetics depend on the limiting electrode and the sufficiency of Li+ ions. Potential Mn dissolution has also been discussed to identify the key factors that need to be considered to construct full cells employing high voltage spinel as the cathode.

  19. Spin correlations and electron transport in MnBi:Au films

    SciTech Connect (OSTI)

    Kharel, P.; Skomski, R.; Sellmyer, D. J.

    2011-04-01

    The structural, magnetic, and electron transport properties of Mn{sub 55-x}Au{sub x}Bi{sub 45} (x = 0, 4.5) thin films prepared by magnetron sputtering have been investigated. The magnetization of the MnBi films decreases and the coercivity increases due to Au doping. The temperature dependence of resistivity between 2 to 300 K shows that the films are metallic but the 4.5% Au-doped film shows a Kondo behavior with resistance minimum at 10.2 K. The magnetoresistance is anisotropic and the positive transverse magnetoresistance is significantly enhanced (16.3% at 70 kOe) by Au doping. We interpret these data in terms of a model in which Au atoms preferentially substitute for Mn atoms on the Mn lattice, and some Mn atoms are displaced to interstitial sites in the NiAs structure. These interstitial Mn atoms are coupled antiferromagnetically to the Mn atoms on the original Mn lattice leading to the large decrease in magnetization, Kondo effect, and the positive magnetoresistance.

  20. Magnetic and structural properties of Zn doped MnV{sub 2}O{sub 4}

    SciTech Connect (OSTI)

    Shahi, Prashant; Shukla, K. K.; Singh, Rahul; Chatterjee, Sandip; Das, A.; Ghosh, A. K.; Nigam, A. K.

    2014-04-24

    The magnetization, Neutron diffraction and X-ray diffraction of Zn doped MnV{sub 2}O{sub 4} as a function of temperature have been measured. It has been observed, with increase of Zn the non-linear orientation of Mn spins with the V spins will decrease which effectively decrease the structural transition temperature more rapidly than Curie Temperature.

  1. Room temperature spin-polarizations of Mn-based antiferromagnetic nanoelectrodes

    SciTech Connect (OSTI)

    Yamada, Toyo Kazu; Vazquez de Parga, Amadeo L.

    2014-11-03

    Antiferromagnets produce no stray field, and therefore, a tip electrode made of antiferromagnetic material has been considered to be the most suitable choice to measure such as magnetoresistance (MR) through single isolated magnetic nanoparticles, molecules, and ultrathin films. Spin polarizations (P) of antiferromagnetic 3-nm, 6-nm, and annealed 3-nm Mn films grown on W tips with a bcc(110) apex as well as bulk-NiMn tips were obtained at 300?K by measuring MR in ultrahigh vacuum by means of spin-polarized scanning tunneling microscopy using a layerwise antiferromagnetically stacking bct-Mn(001) film electrode. The Mn-coated tips with coverages of 3 and 6?nm exhibited P values of 1??1% and 3??2%, respectively, which tips likely contain ?- or strained Mn. With a thermal assist, the crystalline quality and the magnetic stability of the film could increase. The annealed tip exhibited P?=?9??2%. The bulk-NiMn tips exhibit spin polarizations of 0 or 6??2% probably depending on the chemical species (Mn or Ni) present at the apex of the tip. Fe-coated W tips were used to estimate the bct-Mn(001) film spin polarization.

  2. Electric-Field Modulation of Curie Temperature in (Ga, Mn)As Field-Effect Transistor Structures with Varying Channel Thickness and Mn Compositions

    SciTech Connect (OSTI)

    Nishitani, Y.; Endo, M.; Chiba, D.; Matsukura, F.; Ohno, H.

    2010-01-04

    We have investigated the change of T{sub C} of ferromagnetic semiconductor (Ga, Mn)As by changing hole concentration p. The field effect transistor structure was utilized to change p. The relation T{sub C}propor top{sup 0.2} is obtained for three samples, despite the difference of their Mn composition and thickness, indicating that the relation holds over 2 decades of p.

  3. Scanning tunneling microscopy reveals LiMnAs is a room temperature anti-ferromagnetic semiconductor

    SciTech Connect (OSTI)

    Wijnheijmer, A. P.; Koenraad, P. M.; Marti, X.; Holy, V.; Cukr, M.; Novak, V.; Jungwirth, T.

    2012-03-12

    We performed scanning tunneling microscopy and spectroscopy on a LiMnAs(001) thin film epitaxially grown on an InAs(001) substrate by molecular beam epitaxy. While the in situ cleavage exposed only the InAs(110) non-polar planes, the cleavage continued into the LiMnAs thin layer across several facets. We combined both topography and current mappings to confirm that the facets correspond to LiMnAs. By spectroscopy we show that LiMnAs has a band gap. The band gap evidenced in this study, combined with the known Neel temperature well above room temperature, confirms that LiMnAs is a promising candidate for exploring the concepts of high temperature semiconductor spintronics based on antiferromagnets.

  4. Doping against the native propensity of MoS₂: Degenerate hole doping by cation substitution

    SciTech Connect (OSTI)

    Suh, Joonki; Park, Tae-Eon; Lin, Der-Yuh; Fu, Deyi; Park, Joonsuk; Jung, Hee Joon; Chen, Yabin; Ko, Changhyun; Jang, Chaun; Sun, Yinghui; Sinclair, Robert; Chang, Joonyeon; Tongay, Sefaattin; Wu, Junqiao

    2014-12-10

    Layered transition metal dichalcogenides (TMDs) draw much attention as the key semiconducting material for two-dimensional electrical, optoelectronic, and spintronic devices. For most of these applications, both n- and p-type materials are needed to form junctions and support bipolar carrier conduction. However, typically only one type of doping is stable for a particular TMD. For example, molybdenum disulfide (MoS₂) is natively an n-type presumably due to omnipresent electron-donating sulfur vacancies, and stable/controllable p-type doping has not been achieved. The lack of p-type doping hampers the development of charge-splitting p–n junctions of MoS₂, as well as limits carrier conduction to spin-degenerate conduction bands instead of the more interesting, spin-polarized valence bands. Traditionally, extrinsic p-type doping in TMDs has been approached with surface adsorption or intercalation of electron-accepting molecules. However, practically stable doping requires substitution of host atoms with dopants where the doping is secured by covalent bonding. In this work, we demonstrate stable p-type conduction in MoS₂ by substitutional niobium (Nb) doping, leading to a degenerate hole density of ~3 × 10¹⁹ cm⁻³. Structural and X-ray techniques reveal that the Nb atoms are indeed substitutionally incorporated into MoS₂ by replacing the Mo cations in the host lattice. van der Waals p–n homojunctions based on vertically stacked MoS₂ layers are fabricated, which enable gate-tunable current rectification. A wide range of microelectronic, optoelectronic, and spintronic devices can be envisioned from the demonstrated substitutional bipolar doping of MoS₂. From the miscibility of dopants with the host, it is also expected that the synthesis technique demonstrated here can be generally extended to other TMDs for doping against their native unipolar propensity.

  5. MCNPX-CINDER'90 Simulation of Photonuclear Mo-99 Production Experiments

    SciTech Connect (OSTI)

    Kelsey, Charles T. IV [Los Alamos National Laboratory; Chemerizov, Sergey D. [Argonne National Laboratory; Dale, Gregory E. [Los Alamos National Laboratory; Harvey, James T. [NorthStar Medical Radioisotopes; Tkac, Peter [Argonne National Laboratory; Vandegrift, George R III [Argonne National Laboratory

    2011-01-01

    The MCNPX and CINDER'90 codes were used to support design of experiments investigating Mo-99 production with a 20-MeV electron beam. Bremsstrahlung photons produced by the electron beam interacting with the target drive the desired Mo-100({gamma},n)Mo-99 reaction, as well as many undesired reactions important to accurate prediction of radiation hazards. MCNPX is a radiation transport code and CINDER'90 is a transmutation code. They are routinely used together for accelerator activation calculations. Low energy neutron fluxes and production rates for nonneutron and high energy neutron induced reactions computed using MCNPX are inputs to CINDER'90. CINDER'90 presently has only a neutron reaction cross section library up to 25 MeV and normally the other reaction rates come from MCNPX physics models. For this work MCNPX photon flux tallies modified by energy response functions prepared from evaluated photonuclear cross section data were used to tally the reaction rates for CINDER'90 input. The cross section evaluations do not provide isomer to ground state yield ratios so a spin based approximation was used. Post irradiation dose rates were calculated using MCNPX with CINDER'90 produced decay photon spectra. The sensitivity of radionuclide activities and dose rates to beam parameters including energy, position, and profile, as well as underlying isomer assumptions, was investigated. Three experimental production targets were irradiated, two natural Mo and one Mo-100 enriched. Natural Mo foils upstream of the targets were used to analyze beam position and profile by exposing Gafchromic film to the foils after each irradiation. Activation and dose rate calculations were rerun after the experiments using measured beam parameters for comparison with measured Mo-99 activities and dose rates.

  6. In Situ Time-Resolved Characterization of Ni-MoO2 Catalysts for the Water-Gas Shift Reaction

    SciTech Connect (OSTI)

    Wen,W.; Calderon, J.; Brito, J.; Marinkovic, N.; Hanson, J.; Rodriquez, J.

    2008-01-01

    Active catalysts for the water-gas shift (WGS, CO + H2O ? H2 + CO2) reaction were synthesized from nickel molybdates ({beta}-NiMoO4 and nH2O{center_dot}NiMoO4) as precursors, and their structural transformations were monitored using in situ time-resolved X-ray diffraction and X-ray absorption near-edge spectroscopy. In general, the nickel molybdates were not stable and underwent partial reduction in the presence of CO or CO/H2O mixtures at high temperatures. The interaction of {beta}-NiMoO4 with the WGS reactants at 500 C led to the formation of a mixture of Ni (24 nm particle size) and MoO2 (10 nm particle size). These Ni-MoO2 systems displayed good catalytic activity at 350, 400, and 500 C. At 350 and 400 C, catalytic tests revealed that the Ni-MoO2 system was much more active than isolated Ni (some activity) or isolated MoO2 (negligible activity). Thus, cooperative interactions between the admetal and oxide support were probably responsible for the high WGS activity of Ni-MoO2. In a second synthetic approach, the NiMoO4 hydrate was reduced to a mixture of metallic Ni, NiO, and amorphous molybdenum oxide by direct reaction with H2 gas at 350 C. In the first pass of the water-gas shift reaction, MoO2 appeared gradually at 500 C with a concurrent increase of the catalytic activity. For these catalysts, the particle size of Ni (4 nm) was much smaller than that of the MoO2 (13 nm). These systems were found to be much more active WGS catalysts than Cu-MoO2, which in turn is superior to commercial low-temperature Cu-ZnO catalysts.

  7. Method for the production of .sup.99m Tc compositions from .sup.99 Mo-containing materials

    DOE Patents [OSTI]

    Bennett, Ralph G. (Idaho Falls, ID); Christian, Jerry D. (Idaho Falls, ID); Grover, S. Blaine (Idaho Falls, ID); Petti, David A. (Idaho Falls, ID); Terry, William K. (Idaho Falls, ID); Yoon, Woo Y. (Idaho Falls, ID)

    1998-01-01

    An improved method for producing .sup.99m Tc compositions from .sup.99 Mo compounds. .sup.100 Mo metal or .sup.100 MoO.sub.3 is irradiated with photons in a particle (electron) accelerator to ultimately produce .sup.99 MoO.sub.3. This composition is then heated in a reaction chamber to form a pool of molten .sup.99 MoO.sub.3 with an optimum depth of 0.5-5 mm. A gaseous mixture thereafter evolves from the molten .sup.99 MoO.sub.3 which contains vaporized .sup.99 MoO.sub.3, vaporized .sup.99m TcO.sub.3, and vaporized .sup.99m TcO.sub.2. This mixture is then combined with an oxidizing gas (O.sub.2(g)) to generate a gaseous stream containing vaporized .sup.99m Tc.sub.2 O.sub.7 and vaporized .sup.99 MoO.sub.3. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized .sup.99 MoO.sub.3. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized .sup.99m Tc.sub.2 O.sub.7 into a condensed .sup.99m Tc-containing reaction product which is collected.

  8. Method for the production of {sup 99m}Tc compositions from {sup 99}Mo-containing materials

    DOE Patents [OSTI]

    Bennett, R.G.; Christian, J.D.; Grover, S.B.; Petti, D.A.; Terry, W.K.; Yoon, W.Y.

    1998-09-01

    An improved method is described for producing {sup 99m}Tc compositions from {sup 99}Mo compounds. {sup 100}Mo metal or {sup 100}MoO{sub 3} is irradiated with photons in a particle (electron) accelerator to ultimately produce {sup 99}MoO{sub 3}. This composition is then heated in a reaction chamber to form a pool of molten {sup 99}MoO{sub 3} with an optimum depth of 0.5--5 mm. A gaseous mixture thereafter evolves from the molten {sup 99}MoO{sub 3} which contains vaporized {sup 99}MoO{sub 3}, vaporized {sup 99m}TcO{sub 3}, and vaporized {sup 99m}TcO{sub 2}. This mixture is then combined with an oxidizing gas (O{sub 2(g)}) to generate a gaseous stream containing vaporized {sup 99m}Tc{sub 2}O{sub 7} and vaporized {sup 99}MoO{sub 3}. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized {sup 99}MoO{sub 3}. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized {sup 99m}Tc{sub 2}O{sub 7} into a condensed {sup 99m}Tc-containing reaction product which is collected. 1 fig.

  9. Surface oxidation energetics and kinetics on MoS{sub 2} monolayer

    SciTech Connect (OSTI)

    KC, Santosh; Longo, Roberto C.; Wallace, Robert M.; Cho, Kyeongjae

    2015-04-07

    In this work, surface oxidation of monolayer MoS{sub 2} (one of the representative semiconductors in transition-metal dichalcogenides) has been investigated using density functional theory method. Oxygen interaction with MoS{sub 2} shows that, thermodynamically, the surface tends to be oxidized. However, the dissociative absorption of molecular oxygen on the MoS{sub 2} surface is kinetically limited due to the large energy barrier at low temperature. This finding elucidates the air stability of MoS{sub 2} surface in the atmosphere. Furthermore, the presence of defects significantly alters the surface stability and adsorption mechanisms. The electronic properties of the oxidized surface have been examined as a function of oxygen adsorption and coverage as well as substitutional impurities. Our results on energetics and kinetics of oxygen interaction with the MoS{sub 2} monolayer are useful for the understanding of surface oxidation, air stability, and electronic properties of transition-metal dichalcogenides at the atomic scale.

  10. TEM Characterization of High Burn-up Microstructure of U-7Mo Alloy

    SciTech Connect (OSTI)

    Jian Gan; Brandon Miller; Dennis Keiser; Adam Robinson; James Madden; Pavel Medvedev; Daniel Wachs

    2014-04-01

    As an essential part of global nuclear non-proliferation effort, the RERTR program is developing low enriched U-Mo fuels (< 20% U-235) for use in research and test reactors that currently employ highly enriched uranium fuels. One type of fuel being developed is a dispersion fuel plate comprised of U-7Mo particles dispersed in Al alloy matrix. Recent TEM characterizations of the ATR irradiated U-7Mo dispersion fuel plates include the samples with a local fission densities of 4.5, 5.2, 5.6 and 6.3 E+21 fissions/cm3 and irradiation temperatures of 101-136?C. The development of the irradiated microstructure of the U-7Mo fuel particles consists of fission gas bubble superlattice, large gas bubbles, solid fission product precipitates and their association to the large gas bubbles, grain subdivision to tens or hundreds of nanometer size, collapse of bubble superlattice, and amorphisation. This presentation will describe the observed microstructures specifically focusing on the U-7Mo fuel particles. The impact of the observed microstructure on the fuel performance and the comparison of the relevant features with that of the high burn-up UO2 fuels will be discussed.

  11. FeAl and Mo-Si-B Intermetallic Coatings Prepared by Thermal Spraying

    SciTech Connect (OSTI)

    Totemeier, T.C.; Wright, R.N.; Swank, W.D.

    2003-04-22

    FeAl and Mo-Si-B intermetallic coatings for elevated temperature environmental resistance were prepared using high-velocity oxy-fuel (HVOF) and air plasma spray (APS) techniques. For both coating types, the effect of coating parameters (spray particle velocity and temperature) on the microstructure and physical properties of the coatings was assessed. Fe-24Al (wt.%) coatings were prepared using HVOF thermal spraying at spray particle velocities varying from 540 m/s to 700 m/s. Mo-13.4Si-2.6B coatings were prepared using APS at particle velocities of 180 and 350 m/s. Residual stresses in the HVOF FeAl coatings were compressive, while stresses in the APS Mo-Si-B coatings were tensile. In both cases, residual stresses became more compressive with increasing spray particle velocity due to increased peening imparted by the spray particles. The hardness and elastic moduli of FeAl coatings also increased with increasing particle velocity, again due to an increased peening effect. For Mo-Si-B coatings, plasma spraying at 180 m/s resulted in significant oxidation of the spray particles and conversion of the T1 phase into amorphous silica and {alpha}-Mo. The T1 phase was retained after spraying at 350 m/s.

  12. Fragile structural transition in Mo3Sb7

    SciTech Connect (OSTI)

    Yan, Jiaqiang -Q.; McGuire, Michael A; May, Andrew F; Parker, David S.; Mandrus, D. G.; Sales, Brian C.

    2015-08-10

    Mo3Sb7 single crystals lightly doped with Cr, Ru, or Te are studied in order to explore the interplay between superconductivity, magnetism, and the cubic-tetragonal structural transition. The structural transition at 53 K is extremely sensitive to Ru or Te substitution which introduces additional electrons, but robust against Cr substitution. We observed no sign of a structural transition in superconducting Mo2.91Ru0.09Sb7 and Mo3Sb6.975Te0.025. In contrast, 3 at.% Cr doping only slightly suppresses the structural transition to 48 K while leaving no trace of superconductivity above 1.8 K. Analysis of magnetic properties suggests that the interdimer interaction in Mo3Sb7 is near a critical value and essential for the structural transition. Futhermore, all dopants suppress the superconductivity of Mo3Sb7. The tetragonal structure is not necessary for superconductivity.

  13. Ferromagnetic (Ga,Mn)As nanostructures for spintronic applications

    SciTech Connect (OSTI)

    Wosinski, Tadeusz; Andrearczyk, Tomasz; Figielski, Tadeusz; Makosa, Andrzej; Wrobel, Jerzy; Sadowski, Janusz

    2013-12-04

    Magneto-resistive, cross-like nanostructures have been designed and fabricated by electron-beam lithography patterning and chemical etching from thin epitaxial layers of the ferromagnetic semiconductor (Ga,Mn)As. The nanostructures, composed of two perpendicular nanostripes crossing in the middle of their length, represent four-terminal devices, in which an electric current can be driven through any of the two nanostripes. In these devices, a novel magneto-resistive memory effect, related to a rearrangement of magnetic domain walls in the central part of the device, has been demonstrated. It consists in that the zero-field resistance of a nanostripe depends on the direction of previously applied magnetic field. The nanostructures can thus work as two-state devices providing basic elements of nonvolatile memory cells.

  14. Impedance analysis of MnCoCuO NTC ceramic

    SciTech Connect (OSTI)

    Song, S.G. . E-mail: song-ph0@wpmail.paisley.ac.uk; Ling, Z.; Placido, F.

    2005-07-12

    Impedance spectroscopy is often used to analyse the electrical properties of ceramic materials having high-resistive grain boundaries, such as ZnO and SrTiO{sub 3}. Fewer attempts have been made at using this technique for the analysis of inhomogeneous electronic ceramics consisting of grains with differing composition, such as those occurring in negative temperature coefficient (NTC) thermistors. In this study, we have attempted to adopt ac impedance spectroscopy together with other techniques to analyse an NTC thermistor ceramic material. An Mn, Co and Cu multielements transition metal oxide (MnCoCuO) ceramic was prepared by using homogeneous precipitation employing oxalic acid. This material displayed a typical NTC effect, showing an electrical resistance decrease with temperature when dc electrical measurement was performed. The ac impedance spectroscopy analysis showed that there were two peaks in impedance and conductance versus frequency plot. By using an alternative representation of impedance spectra Z'/f versus Z', three distinct relaxation frequency ranges were identified. They are believed to originate, respectively, from the electrode, phase 1 (rich-Cu phase) and phase 2 (poor-Cu phase) grains existing in this ceramic. SEM observation and EDX analysis clearly showed existence of two distinct phase grains. The resistance values were derived from phases 1 and 2 grains based on ac impedance data. The sum of the resistance values was in good agreement with that from dc measurement in the temperature range of 30-95 deg. C. The material constant, B, for the two phases was also calculated, giving 3100 and 3600 K for phases 1 and 2, respectively.

  15. Charged-to-neutral correlation at forward rapidity in Au+Au collisions at sNN<mo>=>200mn> GeV

    SciTech Connect (OSTI)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bltmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Caldern de la Barca Snchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.

    2015-03-20

    Event-by-event fluctuations of the ratio of inclusive charged to photon multiplicities at forward rapidity in Au+Au collision at ?sNN=200 GeV have been studied. Dominant contribution to such fluctuations is expected to come from correlated production of charged and neutral pions. We search for evidences of dynamical fluctuations of different physical origins. Observables constructed out of moments of multiplicities are used as measures of fluctuations. Mixed events and model calculations are used as baselines. Results are compared to the dynamical net-charge fluctuations measured in the same acceptance. A non-zero statistically significant signal of dynamical fluctuations is observed in excess to the model prediction when charged particles and photons are measured in the same acceptance. Thus, we find that, unlike dynamical net-charge fluctuation, charge-neutral fluctuation is not dominated by correlation due to particle decay. Results are compared to the expectations based on the generic production mechanism of pions due to isospin symmetry, for which no significant (< 1%) deviation is observed.

  16. Measurements of dielectron production in Au + Au collisions at sNN<mo>=>200mn> GeV from the STAR experiment

    SciTech Connect (OSTI)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, X.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Jung, K.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, W.; Li, Z. M.; Li, Y.; Li, X.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, Y. G.; Ma, G. L.; Ma, L.; Ma, R.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X.; Sun, Z.; Sun, X. M.; Sun, Y.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Wang, H.; Wang, J. S.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Q. H.; Xu, Z.; Xu, H.; Xu, N.; Xu, Y. F.; Yang, Q.; Yang, Y.; Yang, S.; Yang, Y.; Yang, C.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, J. B.; Zhang, S.; Zhang, Z.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2015-08-24

    We report on measurements of dielectron (e⁺e⁻) production in Au+Au collisions at a center-of-mass energy of 200 GeV per nucleon-nucleon pair using the STAR detector at RHIC. Systematic measurements of the dielectron yield as a function of transverse momentum (pT) and collision centrality show an enhancement compared to a cocktail simulation of hadronic sources in the low invariant-mass region (Mee < 1GeV/c2). This enhancement cannot be reproduced by the ρ-meson vacuum spectral function. In minimum-bias collisions, in the invariant-mass range of 0.30 – 0.76GeV/c², integrated over the full pT acceptance, the enhancement factor is 1.76±0.06(stat.)±0.26(sys.)±0.29(cocktail). The enhancement factor exhibits weak centrality and pT dependence in STAR's accessible kinematic regions, while the excess yield in this invariant-mass region as a function of the number of participating nucleons follows a power-law shape with a power of 1.44±0.10. Models that assume an in-medium broadening of the ρ-meson spectral function consistently describe the observed excess in these measurements. In addition, we report on measurements of ω- and Φ-meson production through their e⁺e⁻ decay channel. These measurements show good agreement with Tsallis blast-wave model predictions, as well as, in the case of the Φ meson, results through its K⁺K⁻ decay channel. In the intermediate invariant-mass region (1.1 < Mee < 3GeV/c²), we investigate the spectral shapes from different collision centralities. Physics implications for possible in-medium modification of charmed hadron production and other physics sources are discussed.

  17. Ab initio study of Fe{sub 2}MnZ (Al, Si, Ge) Heusler alloy using GGA approximation

    SciTech Connect (OSTI)

    Jain, Vivek Kumar Jain, Vishal Lakshmi, N. Venugopalan, K.

    2014-04-24

    Density functional theory based on FP-LAPW method used to investigate the electronic structure of Fe{sub 2}MnZ, shows that the total spin magnetic moment shows a trend consistent with the SlaterPauling curve. The Fe and Mn magnetic moment depend on choice of Z element although the magnetic moment of Z element is negative and less than 0.1 ?{sub B}. Spin polarization calculations evidence 100% spin polarization for Fe{sub 2}MnSi. Fe{sub 2}MnAl and Fe{sub 2}MnGe show metallic behavior with 93%, 98% spin polarization.

  18. Thermal stability of fission gas bubble superlattice in irradiated U10Mo fuel

    SciTech Connect (OSTI)

    Gan, J.; Keiser, D. D.; Miller, B. D.; Robinson, A. B.; Wachs, D. M.; Meyer, M. K.

    2015-09-01

    To investigate the thermal stability of the fission gas bubble superlattice, a key microstructural feature in both irradiated U-7Mo dispersion and U-10Mo monolithic fuel plates, a FIB-TEM sample of the irradiated U-10Mo fuel with a local fission density of 3.51021 fissions/cm3 was used for an in-situ heating TEM experiment. The temperature of the heating holder was raised at a ramp rate of approximately 10 C/min up to ~700 C, kept at that temperature for about 34 min, continued to 850 C with a reduced rate of 5 C/min. The result shows a high thermal stability of the fission gas bubble superlattice. The implication of this observation on the fuel microstructural evolution and performance under irradiation is discussed.

  19. Observation of localized states in atomically thin MoS{sub 2} field effect transistor

    SciTech Connect (OSTI)

    Ghatak, Subhamoy; Pal, Atindra Nath; Ghosh, Arindam

    2013-12-04

    We present electrical transport and low frequency (1/f) noise measurements on mechanically exfoliated single, bi and trilayer MoS{sub 2}-based FET devices on Si/SiO{sub 2} substrate. We find that the electronic states in MoS{sub 2} are localized at low temperatures (T) and conduction happens through variable range hopping (VRH). A steep increase of 1/f noise with decreasing T, typical for localized regime was observed in all of our devices. From gate voltage dependence of noise, we find that the noise power is inversely proportional to square of the number density (? 1/n{sup 2}) for a wide range of T, indicating number density fluctuations to be the dominant source of 1/f noise in these MoS{sub 2} FETs.

  20. Controlling the metal to semiconductor transition of MoS2 and WS2 in solution

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

    Chou, Stanley Shihyao; Yi-Kai Huang; Kim, Jaemyung; Kaehr, Bryan James; Foley, Brian M.; Lu, Ping; Conner Dykstra; Hopkins, Patrick E.; Brinker, C. Jeffrey; Jiaxing Huang; et al

    2015-01-22

    Lithiation-exfoliation produces single to few-layered MoS2 and WS2 sheets dispersible in water. However, the process transforms them from the pristine semiconducting 2H phase to a distorted metallic phase. Recovery of the semiconducting properties typically involves heating of the chemically exfoliated sheets at elevated temperatures. Therefore, it has been largely limited to sheets deposited on solid substrates. We report the dispersion of chemically exfoliated MoS2 sheets in high boiling point organic solvents enabled by surface functionalization and the controllable recovery of their semiconducting properties directly in solution. Ultimately, this process connects the scalability of chemical exfoliation with the simplicity of solutionmore » processing, enabling a facile method for tuning the metal to semiconductor transitions of MoS2 and WS2 within a liquid medium.« less

  1. Electronic and magnetic properties of Mo doped graphene; full potential approach

    SciTech Connect (OSTI)

    Thakur, Jyoti Kashyap, Manish K.; Singh, Mukhtiyar; Saini, Hardev S.

    2015-05-15

    The electronic and magnetic properties of Pristine and Mo doped Graphene have been calculated using WIEN2k implementation of full potential linearized augmented plane wave (FPLAPW) method based on Density Functional Theory (DFT). The exchange and correlation (XC) effects were taken into account by generalized gradient approximation (GGA). The calculated results show that Mo doping creates magnetism in Graphene by shifting the energy levels at E{sub F} and opens up a channel for Graphene to be used in real nanoscale device applications. The unpaired d-electrons of Mo atom are responsible for induced magnetism in Graphene. Magnetic ordering created in Graphene in this way makes it suitable for recording media, magnetic sensors, magnetic inks and spintronic devices.

  2. Highly conducting SrMoO{sub 3} thin films for microwave applications

    SciTech Connect (OSTI)

    Radetinac, Aldin Mani, Arzhang; Ziegler, Jrgen; Alff, Lambert; Komissinskiy, Philipp; Melnyk, Sergiy; Nikfalazar, Mohammad; Zheng, Yuliang; Jakoby, Rolf

    2014-09-15

    We have measured the microwave resistance of highly conducting perovskite oxide SrMoO{sub 3} thin film coplanar waveguides. The epitaxial SrMoO{sub 3} thin films were grown by pulsed laser deposition and showed low mosaicity and smooth surfaces with a root mean square roughness below 0.3?nm. Layer-by-layer growth could be achieved for film thicknesses up to 400?nm as monitored by reflection high-energy electron diffraction and confirmed by X-ray diffraction. We obtained a constant microwave resistivity of 29???cm between 0.1 and 20?GHz by refining the frequency dependence of the transmission coefficients. Our result shows that SrMoO{sub 3} is a viable candidate as a highly conducting electrode material for all-oxide microwave electronic devices.

  3. Exciton-dominant electroluminescence from a diode of monolayer MoS{sub 2}

    SciTech Connect (OSTI)

    Ye, Yu; Ye, Ziliang; Gharghi, Majid; Zhu, Hanyu; Wang, Yuan; Zhao, Mervin; Yin, Xiaobo; Zhang, Xiang

    2014-05-12

    In two-dimensional monolayer MoS{sub 2}, excitons dominate the absorption and emission properties. However, the low electroluminescent efficiency and signal-to-noise ratio limit our understanding of the excitonic behavior of electroluminescence. Here, we study the microscopic origin of the electroluminescence from a diode of monolayer MoS{sub 2} fabricated on a heavily p-type doped silicon substrate. Direct and bound-exciton related recombination processes are identified from the electroluminescence. At a high electron-hole pair injection rate, Auger recombination of the exciton-exciton annihilation of the bound exciton emission is observed at room temperature. Moreover, the efficient electrical injection demonstrated here allows for the observation of a higher energy exciton peak of 2.255?eV in the monolayer MoS{sub 2} diode, attributed to the excited exciton state of a direct-exciton transition.

  4. Two-step growth of two-dimensional WSe2/MoSe2 heterostructures

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

    Gong, Yongji; Lei, Sidong; Lou, Jun; Liu, Zheng; Vajtai, Robert; Zhou, Wu; Ajayan, Pullikel M.

    2015-08-03

    Two dimensional (2D) materials have attracted great attention due to their unique properties and atomic thickness. Although various 2D materials have been successfully synthesized with different optical and electrical properties, a strategy for fabricating 2D heterostructures must be developed in order to construct more complicated devices for practical applications. Here we demonstrate for the first time a two-step chemical vapor deposition (CVD) method for growing transition-metal dichalcogenide (TMD) heterostructures, where MoSe2 was synthesized first and followed by an epitaxial growth of WSe2 on the edge and on the top surface of MoSe2. Compared to previously reported one-step growth methods, thismore » two-step growth has the capability of spatial and size control of each 2D component, leading to much larger (up to 169 μm) heterostructure size, and cross-contamination can be effectively minimized. Furthermore, this two-step growth produces well-defined 2H and 3R stacking in the WSe2/MoSe2 bilayer regions and much sharper in-plane interfaces than the previously reported MoSe2/WSe2 heterojunctions obtained from one-step growth methods. The resultant heterostructures with WSe2/MoSe2 bilayer and the exposed MoSe2 monolayer display rectification characteristics of a p-n junction, as revealed by optoelectronic tests, and an internal quantum efficiency of 91% when functioning as a photodetector. As a result, a photovoltaic effect without any external gates was observed, showing incident photon to converted electron (IPCE) efficiencies of approximately 0.12%, providing application potential in electronics and energy harvesting.« less

  5. Thermal aging modeling and validation on the Mo containing Fe-Cr-Ni alloys

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-04-01

    Thermodynamics of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys is critical knowledge to understand thermal aging effect on the phase stability of Mo-containing austenitic steels, which subsequently facilitates alloy design/improvement and degradation mitigation of these materials for reactor applications. Among the intermetallic phases, Chi (χ), Laves, and Sigma (σ) are often of concern because of their tendency to cause embrittlement of the materials. The focus of this study is thermal stability of the Chi and Laves phases as they were less studied compared to the Sigma phase. Coupled with thermodynamic modeling, thermal stability of intermetallic phases in Mo containing Fe-Cr-Ni alloys was investigated at 1000, 850 and 700 C for different annealing times. The morphologies, compositions and crystal structures of the precipitates of the intermetallic phases were carefully examined by scanning electron microscopy, electron probe microanalysis, X-ray diffraction, and transmission electron microscopy. Three key findings resulted from this study. First, the Chi phase is stable at high temperature, and with decreasing temperature it transforms into the Laves phase that is stable at low temperature. Secondly, Cr, Mo, Ni are soluble in both the Chi and Laves phases, with the solubility of Mo playing a major role in the relative stability of the intermetallic phases. Thirdly, in situ transformation from Chi phase to Laves phase was directly observed, which increased the local strain field, generated dislocations in the intermetallic phases, and altered the precipitate phase orientation relationship with the austenitic matrix. The thermodynamic models that were developed and validated were then applied to evaluating the effect of Mo on the thermal stability of intermetallic phases in type 316 and NF709 stainless steels.

  6. Electrical and photovoltaic characteristics of MoS{sub 2}/Si p-n junctions

    SciTech Connect (OSTI)

    Hao, Lanzhong Liu, Yunjie Gao, Wei; Han, Zhide; Xue, Qingzhong; Zeng, Huizhong; Wu, Zhipeng; Zhu, Jun; Zhang, Wanli

    2015-03-21

    Bulk-like molybdenum disulfide (MoS{sub 2}) thin films were deposited on the surface of p-type Si substrates using dc magnetron sputtering technique and MoS{sub 2}/Si p-n junctions were formed. The vibrating modes of E{sup 1}{sub 2g} and A{sub 1g} were observed from the Raman spectrum of the MoS{sub 2} films. The current density versus voltage (J-V) characteristics of the junction were investigated. A typical J-V rectifying effect with a turn-on voltage of 0.2?V was shown. In different voltage range, the electrical transporting of the junction was dominated by diffusion current and recombination current, respectively. Under the light illumination of 15?mW?cm{sup ?2}, the p-n junction exhibited obvious photovoltaic characteristics with a short-circuit current density of 3.2?mA?cm{sup ?2} and open-circuit voltage of 0.14?V. The fill factor and energy conversion efficiency were 42.4% and 1.3%, respectively. According to the determination of the Fermi-energy level (?4.65?eV) and energy-band gap (?1.45?eV) of the MoS{sub 2} films by capacitance-voltage curve and ultraviolet-visible transmission spectra, the mechanisms of the electrical and photovoltaic characteristics were discussed in terms of the energy-band structure of the MoS{sub 2}/Si p-n junctions. The results hold the promise for the integration of MoS{sub 2} thin films with commercially available Si-based electronics in high-efficient photovoltaic devices.

  7. Unoccupied electronic structure of Ni2MnGa ferromagnetic shape memory alloy

    SciTech Connect (OSTI)

    Maniraj, M.; D?Souza, S. W.; Rai, Abhishek; Schlagel, D. L.; Lograsso, T. A.; Chakrabarti, Aparna; Barman, S. R.

    2015-08-20

    Momentum resolved inverse photoemission spectroscopy measurements show that the dispersion of the unoccupied bands of Ni2MnGa is significant in the austenite phase. Furthermore, in the martensite phase, it is markedly reduced, which is possibly related to the structural transition to an incommensurate modulated state in the martensite phase. Finally, based on the first principle calculations of the electronic structure of NiMnGa, we show that the modification of the spectral shape with surface composition is related to change in the hybridization between the Mn 3d and Ni 3d-like states that dominate the unoccupied conduction band.

  8. Recent progress of magnetocaloric effect and magnetic refrigerant materials of Mn compounds (invited)

    SciTech Connect (OSTI)

    Wada, H. Takahara, T.; Katagiri, K.; Ohnishi, T.; Soejima, K.; Yamashita, K.

    2015-05-07

    Magnetocaloric and related properties of Ru and Ni substituted (MnFe){sub 2}(PSi) are presented. It is found that Ru and Ni are effective doping elements to reduce the thermal hysteresis of (MnFe){sub 2}(PSi). The origin of the thermal hysteresis is discussed on the basis of a thermodynamic model. It is shown that the elastic energy is responsible for the thermal hysteresis. We also show recent developments of the production process of Mn compounds in an industrial scale.

  9. Modulation on Ni{sub 2}MnGa(001) surface (Journal Article) | SciTech

    Office of Scientific and Technical Information (OSTI)

    Connect Modulation on Ni{sub 2}MnGa(001) surface Citation Details In-Document Search Title: Modulation on Ni{sub 2}MnGa(001) surface We report periodic modulation on (001) surface of Ni2MnGa ferromagnetic shape memory alloy. For the stoichiometric surface, analysis of the low energy electron diffraction (LEED) spot profiles shows that the modulation is incommensurate. The modulation appears at 200 K, concomitant with the first order structural transition to the martensitic phase. Authors:

  10. Magnetostructural phase transformations in Tb 1-x Mn 2 (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect SciTech Connect Search Results Journal Article: Magnetostructural phase transformations in Tb 1-x Mn 2 Citation Details In-Document Search Title: Magnetostructural phase transformations in Tb 1-x Mn 2 Magnetism and phase transformations in non-stoichiometric Tb1-xMn2 (x = 0.056, 0.039) have been studied as functions of temperature and magnetic field using magnetization, heat capacity, and X-ray powder diffraction measurements. Lowering the temperature, the compounds

  11. Quantum Anomalous Hall Effect in Hg_1-yMn_yTe Quantum Wells

    SciTech Connect (OSTI)

    Liu, Chao-Xing; Qi, Xiao-Liang; Dai, Xi; Fang, Zhong; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-03-19

    The quantum Hall effect is usually observed when the two-dimensional electron gas is subjected to an external magnetic field, so that their quantum states form Landau levels. In this work we predict that a new phenomenon, the quantum anomalous Hall effect, can be realized in Hg{sub 1-y}Mn{sub y}Te quantum wells, without the external magnetic field and the associated Landau levels. This effect arises purely from the spin polarization of the Mn atoms, and the quantized Hall conductance is predicted for a range of quantum well thickness and the concentration of the Mn atoms. This effect enables dissipationless charge current in spintronics devices.

  12. Planar Hall effect in Y{sub 3}Fe{sub 5}O{sub 12}/IrMn films

    SciTech Connect (OSTI)

    Zhang, X. Zou, L. K.

    2014-12-29

    The planar Hall effect of IrMn on an yttrium iron garnet (YIG = Y{sub 3}Fe{sub 5}O{sub 12}) was measured in the magnetic field rotating in the film plane. The magnetic field angular dependence of planar Hall resistance (PHR) was observed in YIG/IrMn bilayer at different temperatures, while the Gd{sub 3}Ga{sub 5}O{sub 12}/IrMn film shows constant PHR for different magnetic field angles at both 10 K and 300 K. This provides evidence that IrMn has interfacial spins which can be led by ferrimagnetic layer in YIG/IrMn structure. A hysteresis can be observed in PHR-magnetic field angle loop of YIG/IrMn film at 10 K, indicative of the irreversible switching of IrMn interfacial spins at low temperature.

  13. Rapid first-cycle lithiation strategy for enhanced performance of Li-MoS2

    Office of Scientific and Technical Information (OSTI)

    batteries as identified by in situ studies. (Journal Article) | SciTech Connect Rapid first-cycle lithiation strategy for enhanced performance of Li-MoS2 batteries as identified by in situ studies. Citation Details In-Document Search Title: Rapid first-cycle lithiation strategy for enhanced performance of Li-MoS2 batteries as identified by in situ studies. Abstract not provided. Authors: Jiayu Wan ; Wenzhong Bao ; Yang Liu ; Jiaqi Dai ; Fei Shen ; Lihui Zhou ; Xinghan Cai ; Dan Urban ;

  14. Neutrino-nucleus scattering of {sup 95,97}Mo and {sup 116}Cd

    SciTech Connect (OSTI)

    Ydrefors, E.; Almosly, W.; Suhonen, J.

    2013-12-30

    Accurate knowledge about the nuclear responses to supernova neutrinos for relevant nuclear targets is important both for neutrino detection and for astrophysical applications. In this paper we discuss the cross sections for the charged-current neutrino-nucleus scatterings off {sup 95,97}Mo and {sup 116}Cd. The microscopic quasiparticle-phonon model is adopted for the odd-even nuclei {sup 95,97}Mo. In the case of {sup 116}Cd we present cross sections both for the Bonn one-boson-exchange potential and self-consistent calculations based on modern Skyrme interactions.

  15. Valence and metal/silicate partitioning of Mo: Implications for conditions

    Office of Scientific and Technical Information (OSTI)

    of Earth accretion and core formation (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Valence and metal/silicate partitioning of Mo: Implications for conditions of Earth accretion and core formation Citation Details In-Document Search Title: Valence and metal/silicate partitioning of Mo: Implications for conditions of Earth accretion and core formation Authors: Righter, K. ; Danielson, L.R. ; Pando, K.M. ; Shofner, G.A. ; Sutton, S.R. ; Newville, M. ; Lee,

  16. Morgan Wascko Imperial College London M.O. Wascko FNAL User's Meeting

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

    from the BooNEs Morgan Wascko Imperial College London M.O. Wascko FNAL User's Meeting M. Sorel Goals of the BooNEs * MiniBooNE: Confirm or rule out LSND * SciBooNE: * Near detector measurements for MiniBooNE * Precise cross section measurements * Especially useful for T2K 2 M.O. Wascko FNAL User's Meeting Goals of the BooNEs * MiniBooNE: Confirm or rule out LSND * SciBooNE: * Near detector measurements for MiniBooNE * Precise cross section measurements * Especially useful for T2K 2 W + ν µ n p

  17. Site-dependent free energy barrier for proton reduction on MoS2 edges

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Site-dependent free energy barrier for proton reduction on MoS2 edges Citation Details In-Document Search Title: Site-dependent free energy barrier for proton reduction on MoS2 edges Authors: Choi, W ; Wood, B C ; Schwegler, E ; Ogitsu, T Publication Date: 2013-05-30 OSTI Identifier: 1113397 Report Number(s): LLNL-JRNL-639087 DOE Contract Number: W-7405-ENG-48 Resource Type: Journal Article Resource Relation: Journal Name: Journal of Physical Chemistry C,

  18. Primary arm spacing in chill block melt spun Ni-Mo alloys

    SciTech Connect (OSTI)

    Tewari, S.N.; Glasgow, T.K.

    1986-01-01

    Chill block melt spun ribbons of Ni-Mo binary alloys containing 8.0 to 41.8 wt % Mo have been prepared under carefully controlled processing conditions. The growth velocity has been determined as a function of distance from the quench surface from the observed ribbon thickness dependence on the melt puddle residence time. Primary arm spacings measured at the midribbon thickness locations show a dependence on growth velocity and alloy composition which is expected from dendritic growth models for binary alloys directionally solidified in a positive temperature gradient.

  19. Single-layer MoS{sub 2} roughness and sliding friction quenching by interaction with atomically flat substrates

    SciTech Connect (OSTI)

    Quereda, J.; Castellanos-Gomez, A.; Agrat, N.; Rubio-Bollinger, G.

    2014-08-04

    We experimentally study the surface roughness and the lateral friction force in single-layer MoS{sub 2} crystals deposited on different substrates: SiO{sub 2}, mica, and hexagonal boron nitride (h-BN). Roughness and sliding friction measurements are performed by atomic force microscopy. We find a strong dependence of the MoS{sub 2} roughness on the underlying substrate material, being h-BN the substrate which better preserves the flatness of the MoS{sub 2} crystal. The lateral friction also lowers as the roughness decreases, and attains its lowest value for MoS{sub 2} flakes on h-BN substrates. However, it is still higher than for the surface of a bulk MoS{sub 2} crystal, which we attribute to the deformation of the flake due to competing tip-to-flake and flake-to-substrate interactions.

  20. High blue-near ultraviolet photodiode response of vertically stacked graphene-MoS{sub 2}-metal heterostructures

    SciTech Connect (OSTI)

    Wi, Sungjin; Chen, Mikai; Nam, Hongsuk; Liu, Amy C.; Meyhofer, Edgar; Liang, Xiaogan

    2014-06-09

    We present a study on the photodiode response of vertically stacked graphene/MoS{sub 2}/metal heterostructures in which MoS{sub 2} layers are doped with various plasma species. In comparison with undoped heterostructures, such doped ones exhibit significantly improved quantum efficiencies in both photovoltaic and photoconductive modes. This indicates that plasma-doping-induced built-in potentials play an important role in photocurrent generation. As compared to indium-tin-oxide/ MoS{sub 2}/metal structures, the presented graphene/MoS{sub 2}/metal heterostructures exhibit greatly enhanced quantum efficiencies in the blue-near ultraviolet region, which is attributed to the low density of recombination centers at graphene/MoS{sub 2} heterojunctions. This work advances the knowledge for making photo-response devices based on layered materials.

  1. Modeling and Characterization of the Magnetocaloric Effect in Ni2MnGa Materials

    SciTech Connect (OSTI)

    Nicholson, Don M; Odbadrakh, Khorgolkhuu; Rios, Orlando; Hodges, Jason P; Ludtka, Gerard Michael; Porter, Wallace D; Sefat, A. S.; Rusanu, Aurelian; Evans III, Boyd Mccutchen

    2012-01-01

    Magnetic shape memory alloys have great promise as magneto-caloric effect refrigerant materials due to their combined magnetic and structural transitions. Computational and experimental research is reported on the Ni2MnGa material system. The magnetic states of this system have been explored using the Wang-Landau statistical approach in conjunction with the Locally Self-consistent Multiple-Scattering (LSMS) method to explore the magnetic states responsible for the magnet-caloric effect in this material. The effects of alloying agents on the transition temperatures of the Ni2MnGa alloy were investigated using differential scanning calorimetry (DSC) and superconducting quantum interference device (SQUID). Neutron scattering experiments were performed to observe the structural and magnetic phase transformations at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) on alloys of Ni-Mn-Ga and Ni-Mn-Ga-Cu-Fe. Data from the observations are discussed in comparison with the computational studies.

  2. Synthesis and characterization of MnPS{sub 3} for hydrogen sorption

    SciTech Connect (OSTI)

    Ismail, N.; Temerk, Y.M.; El-Meligi, A.A.; Badr, M.A.; Madian, M.

    2010-05-15

    Single phase MnPS{sub 3} powder was prepared by solid state reaction between Mn, S and P carried out at 650 deg. C in evacuated silica tube. The structure, morphology and sorption characteristics of the prepared solid were investigated. The results revealed that the obtained MnPS{sub 3} compound was capable of adsorbing 3.5 wt% hydrogen at -193 deg. C and a pressure of 30 bar. Little amount of hydrogen (0.07 wt%) was adsorbed at room temperature. The hydrogen adsorption/desorption cycles at various temperatures did not result in irreversible chemical structural changes of the MnPS{sub 3} compound, but the microstructure after hydrogen cycling diminished and became finer. - Graphical abstract: Atomic building of MPS{sub 3}

  3. In-situ Electrical Conductivity of LixMnO2 Nanowires as a Function...

    Office of Scientific and Technical Information (OSTI)

    of LixMnO2 Nanowires as a Function of "x" and Size Authors: Le, Mya ; Liu, Yu ; Wang, Hui ; Dutta, Rajen ; Yan, Wenbo ; Hemminger, John C ; Wu, Ruqian ; Penner, Reginald...

  4. File:USDA-CE-Production-GIFmaps-MN.pdf | Open Energy Information

    Open Energy Info (EERE)

    MN.pdf Jump to: navigation, search File File history File usage Minnesota Ethanol Plant Locations Size of this preview: 776 600 pixels. Full resolution (1,650 1,275...

  5. Spectroscopic properties of (PVA+ZnO):Mn{sup 2+} polymer films

    SciTech Connect (OSTI)

    Rani, Ch.; Raju, D. Siva; Bindu, S. Hima; Krishna, J. Suresh; Raju, Ch. Linga

    2015-05-15

    Electron Paramagnetic Resonance (EPR), optical absorption and infrared spectral studies have been carried out on Mn{sup 2+} ions doped in poly(vinyl alcohol) complexed with zinc oxide polymer films prepared by solution cast technique. The EPR spectra of 1 mol% Mn{sup 2+} ions doped polymer complex (PVA+ZnO) at room temperature exhibit sextet hyperfine structure (hfs), centered at 2.01. The spin-Hamiltonian parameter values indicate that the ground state of Mn{sup 2+} ion in d{sup 5} and the site symmetry around Mn{sup 2+} ions in tetragonally distorted octa hedral site. The optical absorption spectra exhibits two bands centered at 275nm at 437nm. The FTIR spectrum exhibits bands characteristic of stretching and banding vibrations of O-H, C-H and C=C groups.

  6. Effect of Mn substitution on the transport properties of co-sputtered...

    Office of Scientific and Technical Information (OSTI)

    a high spin polarization with a high Curie temperature to be applied in spintronic devices, and in order to further study the effect of Mn contents on the physical properties ...

  7. Electrochemical Performances of LiMnPO4 Synthesized from Non...

    Office of Scientific and Technical Information (OSTI)

    Li1.1MnPO4 exhibits the most stable cycling ability probably because of the existence of a trace amount of Li3PO4 impurity that functions as a solid-state electrolyte on...

  8. X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation...

    Office of Scientific and Technical Information (OSTI)

    Ca Cluster in the Water-Oxidation Complex of Photosystem II Citation Details In-Document Search Title: X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation Complex ...

  9. Phase stability of the SrMn O 3 hexagonal perovskite system at high

    Office of Scientific and Technical Information (OSTI)

    pressure and temperature (Journal Article) | DOE PAGES Publisher's Accepted Manuscript: Phase stability of the SrMn O 3 hexagonal perovskite system at high pressure and temperature Title: Phase stability of the SrMn O 3 hexagonal perovskite system at high pressure and temperature Authors: Nielsen, Morten Bormann ; Ceresoli, Davide ; Parisiades, Paraskevas ; Prakapenka, Vitali B. ; Yu, Tony ; Wang, Yanbin ; Bremholm, Martin Publication Date: 2014-12-01 OSTI Identifier: 1180602 Grant/Contract

  10. Phase stability of the SrMn O 3 hexagonal perovskite system at high

    Office of Scientific and Technical Information (OSTI)

    pressure and temperature (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Phase stability of the SrMn O 3 hexagonal perovskite system at high pressure and temperature Citation Details In-Document Search Title: Phase stability of the SrMn O 3 hexagonal perovskite system at high pressure and temperature Authors: Nielsen, Morten Bormann ; Ceresoli, Davide ; Parisiades, Paraskevas ; Prakapenka, Vitali B. ; Yu, Tony ; Wang, Yanbin ; Bremholm, Martin Publication

  11. DETECTION OF $sup 54$Mn IN FOOD SAMPLES (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    DETECTION OF $sup 54$Mn IN FOOD SAMPLES Citation Details In-Document Search Title: DETECTION OF $sup 54$Mn IN FOOD SAMPLES Authors: Neilson, H. ; Yakabe, H.M. Publication Date: 1966-01-01 OSTI Identifier: 4590897 Resource Type: Journal Article Resource Relation: Journal Name: Health Physics (England); Journal Volume: Vol: 12; Other Information: Orig. Receipt Date: 31-DEC-66 Research Org: Food and Drug Administration, Washington, D.C. Country of Publication: Country unknown/Code not available

  12. Electric contributions to magnetic force microscopy response from graphene and MoS{sub 2} nanosheets

    SciTech Connect (OSTI)

    Li, Lu Hua Chen, Ying

    2014-12-07

    Magnetic force microscopy (MFM) signals have recently been detected from whole pieces of mechanically exfoliated graphene and molybdenum disulfide (MoS{sub 2}) nanosheets, and magnetism of the two nanomaterials was claimed based on these observations. However, non-magnetic interactions or artefacts are commonly associated with MFM signals, which make the interpretation of MFM signals not straightforward. A systematic investigation has been done to examine possible sources of the MFM signals from graphene and MoS{sub 2} nanosheets and whether the MFM signals can be correlated with magnetism. It is found that the MFM signals have significant non-magnetic contributions due to capacitive and electrostatic interactions between the nanosheets and conductive cantilever tip, as demonstrated by electric force microscopy and scanning Kevin probe microscopy analyses. In addition, the MFM signals of graphene and MoS{sub 2} nanosheets are not responsive to reversed magnetic field of the magnetic cantilever tip. Therefore, the observed MFM response is mainly from electric artefacts and not compelling enough to correlate with magnetism of graphene and MoS{sub 2} nanosheets.

  13. Ferromagnetic superexchange in insulating Cr2MoO6 by controlling orbital hybridization

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

    Zhu, M.; Do, D.; Dela Cruz, Clarina R.; Dun, Zhiling; Cheng, J. -G.; Goto, H.; Uwatoko, Yoshiya; Zou, T.; Zhou, Haidon D.; Mahanti, Subhendra D.; et al

    2015-09-11

    We report the magnetic and electronic structures of the newly synthesized inverse-trirutile compound Cr2MoO6. Despite the same crystal symmetry and similar bond-lengths and bond-angles to Cr2TeO6, Cr2MoO6 possesses a magnetic structure of the Cr2MoO6 type, different from that seen in Cr2TeO6. Ab-initio electronic structure calculations show that the sign and strength of the Cr-O-Cr exchange coupling is strongly influenced by the hybridization between Mo 4d and O 2p orbitals. This result further substantiates our recently proposed mechanism for tuning the exchange interaction between two magnetic atoms by modifying the electronic states of the non-magnetic atoms in the exchange path throughmore »orbital hybridization. This approach is fundamentally different from the conventional methods of controlling the exchange interaction by either carrier injection or through structural distortions.« less

  14. MoS{sub 2} functionalization for ultra-thin atomic layer deposited dielectrics

    SciTech Connect (OSTI)

    Azcatl, Angelica; McDonnell, Stephen; Santosh, K.C.; Peng, Xin; Dong, Hong; Qin, Xiaoye; Addou, Rafik; Lu, Ning; Kim, Moon J.; Cho, Kyeongjae; Wallace, Robert M.; Mordi, Greg I.; Kim, Jiyoung

    2014-03-17

    The effect of room temperature ultraviolet-ozone (UV-O{sub 3}) exposure of MoS{sub 2} on the uniformity of subsequent atomic layer deposition of Al{sub 2}O{sub 3} is investigated. It is found that a UV-O{sub 3} pre-treatment removes adsorbed carbon contamination from the MoS{sub 2} surface and also functionalizes the MoS{sub 2} surface through the formation of a weak sulfur-oxygen bond without any evidence of molybdenum-sulfur bond disruption. This is supported by first principles density functional theory calculations which show that oxygen bonded to a surface sulfur atom while the sulfur is simultaneously back-bonded to three molybdenum atoms is a thermodynamically favorable configuration. The adsorbed oxygen increases the reactivity of MoS{sub 2} surface and provides nucleation sites for atomic layer deposition of Al{sub 2}O{sub 3}. The enhanced nucleation is found to be dependent on the thin film deposition temperature.

  15. Magnetic Force Microscopy Study of Zr2Co11 -Based Nanocrystalline Materials: Effect of Mo Addition

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

    Yue, Lanping; Jin, Yunlong; Zhang, Wenyong; Sellmyer, David J.

    2015-01-01

    Tmore » he addition of Molybdenum was used to modify the nanostructure and enhance coercivity of rare-earth-free Zr2Co11-based nanocrystalline permanent magnets. he effect of Mo addition on magnetic domain structures of melt spun nanocrystalline Zr16Co84-xMox(x=0, 0.5, 1, 1.5, and 2.0) ribbons has been investigated. It was found that magnetic properties and local domain structures are strongly influenced by Mo doping. he coercivity of the samples increases with the increase in Mo content (x≤1.5). he maximum energy product(BH)maxincreases with increasingxfrom 0.5 MGOe forx=0to a maximum value of 4.2 MGOe forx=1.5. he smallest domain size with a relatively short magnetic correlation length of 128 nm and largest root-mean-square phase shiftΦrmsvalue of 0.66° are observed for thex=1.5. he optimal Mo addition promotes magnetic domain structure refinement and thus leads to a significant increase in coercivity and energy product in this sample.« less

  16. Equation of state of bcc-Mo by static volume compression to 410 GPa

    SciTech Connect (OSTI)

    Akahama, Yuichi; Hirao, Naohisa; Ohishi, Yasuo; Singh, Anil K.

    2014-12-14

    Unit cell volumes of Mo and Pt have been measured simultaneously to ≈400 GPa by x-ray powder diffraction using a diamond anvil cell and synchrotron radiation source. The body-centered cubic (bcc) phase of Mo was found to be stable up to 410 GPa. The equation of state (EOS) of bcc-Mo was determined on the basis of Pt pressure scale. A fit of Vinet EOS to the volume compression data gave K{sub 0} = 262.3(4.6) GPa, K{sub 0}′ = 4.55(16) with one atmosphere atomic volume V{sub 0} = 31.155(24) A{sup 3}. The EOS was in good agreement with the previous ultrasonic data within pressure difference of 2.5%–3.3% in the multimegabar range, though the EOS of Mo proposed from a shock compression experiment gave lower pressure by 7.2%–11.3% than the present EOS. The agreement would suggest that the Pt pressure scale provides an accurate pressure value in an ultra-high pressure range.

  17. Effect of mechanical strain on electronic properties of bulk MoS{sub 2}

    SciTech Connect (OSTI)

    Kumar, Sandeep Kumar, Jagdish Sastri, O. S. K. S.

    2015-05-15

    Ab-initio density functional theory based calculations of electronic properties of bulk and monolayer Molybdenum di-Sulfide (MoS{sub 2}) have been performed using all electron Full Potential Linearised Augmentad Plane Wave (FPLAPW) method using Elk code. We have used Generalised Gradient Approximation (GGA) for exchange and correlation functionals and performed calculaitons of Lattice parameters, Density Of States (DOS) and Band Structure (BS). Band structure calculations revealed that bulk MoS{sub 2} has indirect band gap of 0.97 eV and mono-layer MoS{sub 2} has direct band gap which has increased to 1.71 eV. These are in better agreement with experimental values as compared with the other calculations using pseudo-potential code. The effect of mechanical strain on the electronic properties of bulk MoS{sub 2} has also been studied. For the different values of compressive strain (varying from 2% to 8% in steps of 2%) along the c-axis, the corresponding DOS and BS are obtained. We observed that the band gap decreases by about 15% for every 2% increase in strain along the c-axis.

  18. On the combined gradient-stochastic plasticity model: Application to Mo-micropillar compression

    SciTech Connect (OSTI)

    Konstantinidis, A. A.; Zhang, X.; Aifantis, E. C.

    2015-02-17

    A formulation for addressing heterogeneous material deformation is proposed. It is based on the use of a stochasticity-enhanced gradient plasticity model implemented through a cellular automaton. The specific application is on Mo-micropillar compression, for which the irregularities of the strain bursts observed have been experimentally measured and theoretically interpreted through Tsallis' q-statistics.

  19. EIS-0475: Disposition of the Bannister Federal Complex, Kansas City, MO

    Broader source: Energy.gov [DOE]

    NNSA/DOE announces its intent to prepare an EIS for the disposition of the Bannister Federal Complex, Kansas City, MO. NNSA previously decided in a separate NEPA review (EA-1592) to relocate its operations from the Bannister Federal Complex to a newly constructed industrial campus eight miles from the current location.

  20. The structure of the Caenorhabditis elegans manganese superoxide dismutase MnSOD-3-azide complex

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

    Hunter, Gary J.; Trinh, Chi H.; Bonetta, Rosalin; Stewart, Emma E.; Cabelli, Diane E.; Hunter, Therese

    2015-08-27

    C. elegans MnSOD-3 has been implicated in the longevity pathway and its mechanism of catalysis is relevant to the aging process and carcinogenesis. The structures of MnSOD-3 provide unique crystallographic evidence of a dynamic region of the tetrameric interface (residues 41–54). We have determined the structure of the MnSOD-3-azide complex to 1.77-Å resolution. The analysis of this complex shows that the substrate analog, azide, binds end-on to the manganese center as a sixth ligand and that it ligates directly to a third and new solvent molecule also positioned within interacting distance to the His30 and Tyr34 residues of the substratemore » access funnel. This is the first structure of a eukaryotic MnSOD-azide complex that demonstrates the extended, uninterrupted hydrogen-bonded network that forms a proton relay incorporating three outer sphere solvent molecules, the substrate analog, the gateway residues, Gln142, and the solvent ligand. This configuration supports the formation and release of the hydrogen peroxide product in agreement with the 5-6-5 catalytic mechanism for MnSOD. The high product dissociation constant k₄ of MnSOD-3 reflects low product inhibition making this enzyme efficient even at high levels of superoxide.« less

  1. Hydrothermal synthesis of Mn vanadate nanosheets and visible-light photocatalytic performance for the degradation of methyl blue

    SciTech Connect (OSTI)

    Pei, L.Z. Xie, Y.K.; Pei, Y.Q.; Jiang, Y.X.; Yu, H.Y.; Cai, Z.Y.

    2013-07-15

    Graphical abstract: - Highlights: Mn vanadate nanosheets have been synthesized by simple hydrothermal process. The formation of Mn vanadate nanosheets can be controlled by growth conditions. Mn vanadate nanosheets exhibit good photocatalytic activities for methyl blue. - Abstract: Mn vanadate nanosheets have been synthesized via a facile hydrothermal route using ammonium metavanadate and Mn acetate as the raw materials, polyvinyl pyrrolidone (PVP) as the surfactant. X-ray diffraction (XRD) shows that the Mn vanadate nanosheets are composed of monoclinic MnV{sub 2}O{sub 6} phase. Scanning electron microscopy (SEM) observation indicates that the nanosheets have the average thickness of about 50 nm, length of 210 ?m and width of 800 nm to 2 ?m. The growth process of the Mn vanadate nanosheets has also been discussed based on the analysis of the roles of the growth conditions on the formation of the Mn vanadate nanosheets. The nanosheets show good photocatalytic activities for the degradation of methylene blue (MB) under visible light irradiation. About 72.96% MB can be degraded after visible light irradiation for 1 h over 10 mg Mn vanadate nanosheets in 10 mL MB solution with the concentration of 10 mg L{sup ?1}.

  2. The carburization of transition metal molybdates (MxMoO?, M= Cu, Ni or Co) and the generation of highly active metal/carbide catalysts for CO? hydrogenation

    SciTech Connect (OSTI)

    Rodriguez, Jose A.; Xu, Wenqian; Ramirez, Pedro J.; Stachiola, Dario; Brito, Joaquin L.

    2015-05-06

    A new approach has been tested for the preparation of metal/Mo?C catalysts using mixed-metal oxide molybdates as precursors. Synchrotron-based in situ time-resolved X-ray diffraction was used to study the reduction and carburization processes of Cu?(MoO?)?(OH)?, a-NiMoO? and CoMoO?nH?O by thermal treatment under mixtures of hydrogen and methane. In all cases, the final product was ?-Mo?C and a metal phase (Cu, Ni, or Co), but the transition sequence varied with the different metals, and it could be related to the reduction potential of the Cu?, Ni? and Co? cations inside each molybdate. The synthesized Cu/Mo?C, Ni/Mo?C and Co/Mo?C catalysts were highly active for the hydrogenation of CO?. The metal/Mo?C systems exhibited large variations in the selectivity towards methanol, methane and CnH?n?? (n > 2) hydrocarbons depending on the nature of the supported metal and its ability to cleave C-O bonds. Cu/Mo?C displayed a high selectivity for CO and methanol production. Ni/Mo?C and Co/Mo?C were the most active catalysts for the activation and full decomposition of CO?, showing high selectivity for the production of methane (Ni case) and CnH?n?? (n > 2) hydrocarbons (Co case).

  3. Modeling of Interaction Layer Growth Between U-Mo Particles and an Al Matrix

    SciTech Connect (OSTI)

    Yeon Soo Kim; G. L. Hofman; Ho Jin Ryu; Jong Man Park; A. B. Robinson; D. M. Wachs

    2013-12-01

    Interaction layer growth between U-Mo alloy fuel particles and Al in a dispersion fuel is a concern due to the volume expansion and other unfavorable irradiation behavior of the interaction product. To reduce interaction layer (IL) growth, a small amount of Si is added to the Al. As a result, IL growth is affected by the Si content in the Al matrix. In order to predict IL growth during fabrication and irradiation, empirical models were developed. For IL growth prediction during fabrication and any follow-on heating process before irradiation, out-of-pile heating test data were used to develop kinetic correlations. Two out-of-pile correlations, one for the pure Al matrix and the other for the Al matrix with Si addition, respectively, were developed, which are Arrhenius equations that include temperature and time. For IL growth predictions during irradiation, the out-of-pile correlations were modified to include a fission-rate term to consider fission enhanced diffusion, and multiplication factors to incorporate the Si addition effect and the effect of the Mo content. The in-pile correlation is applicable for a pure Al matrix and an Al matrix with the Si content up to 8 wt%, for fuel temperatures up to 200 degrees C, and for Mo content in the range of 6 10wt%. In order to cover these ranges, in-pile data were included in modeling from various tests, such as the US RERTR-4, -5, -6, -7 and -9 tests and Koreas KOMO-4 test, that were designed to systematically examine the effects of the fission rate, temperature, Si content in Al matrix, and Mo content in U-Mo particles. A model converting the IL thickness to the IL volume fraction in the meat was also developed.

  4. Novel Processing of mo-si-b Intermetallics for improved efficiency of power systems

    SciTech Connect (OSTI)

    M.J. Kramer; O. Degirmen; A.J. Thom; M. Akinc

    2004-09-30

    Multiphase composite alloys based on the Mo-Si-B system are candidate materials for ultra-high temperature applications. In non load-bearing applications such as thermal barrier coatings or heat exchangers in fossil fuel burners, these materials may be ideally suited. Alloys based on the Mo{sub 5}Si{sub 3}B{sub x} phase (Tl phase) possess excellent oxidation resistance to at least 1600 C in synthetic air atmospheres. However, the ability of Tl-based alloys to resist aggressive combustion environments has not yet been determined. The present work seeks to investigate the resistance of these Mo-Si-B alloys to simulated combustion atmospheres. Material was pre-alloyed by combustion synthesis, and samples for testing were prepared by classic powder metallurgical processing techniques. Precursor material synthesized by self-heating-synthesis was sintered to densities exceeding 98% in an argon atmosphere at 1800 C. The approximate phase assemblage of the material was 57% Tl, 29% MoB, 14% MoSi{sub 2} (wt%). The alloy was oxidized from 1000-1100 C in flowing air containing water vapor at 18 Torr. At 1000 C the material achieved a steady state mass loss, and at 1100 C the material undergoes a steady state mass gain. The oxidation rate of these alloys in this temperature regime was accelerated by the presence of water vapor compared to oxidation in dry air. The results of microstructural analysis of the tested alloys will be discussed. Techniques and preliminary results for fabricating near-net-shaped parts will also be presented.

  5. Inverse magnetocaloric effect in Mn{sub 2}NiGa and Mn{sub 1.75}Ni{sub 1.25}Ga magnetic shape memory alloys

    SciTech Connect (OSTI)

    Singh, Sanjay Barman, S. R.; Esakki Muthu, S.; Arumugam, S.; Senyshyn, A.; Rajput, P.; Suard, E.

    2014-02-03

    Inverse magnetocaloric effect is demonstrated in Mn{sub 2}NiGa and Mn{sub 1.75}Ni{sub 1.25}Ga magnetic shape memory alloys. The entropy change at the martensite transition is larger in Mn{sub 1.75}Ni{sub 1.25}Ga, and it increases linearly with magnetic field in both the specimens. Existence of inverse magnetocaloric effect is consistent with the observation that magnetization in the martensite phase is smaller than the austenite phase. Although the Mn content is smaller in Mn{sub 1.75}Ni{sub 1.25}Ga, from neutron diffraction, we show that the origin of inverse magnetocaloric effect is the antiferromagnetic interaction between the Mn atoms occupying inequivalent sites.

  6. MoS{sub 2}@ZnO nano-heterojunctions with enhanced photocatalysis and field emission properties

    SciTech Connect (OSTI)

    Tan, Ying-Hua; Yu, Ke Li, Jin-Zhu; Fu, Hao; Zhu, Zi-Qiang

    2014-08-14

    The molybdenum disulfide (MoS{sub 2})@ZnO nano-heterojunctions were successfully fabricated through a facile three-step synthetic process: prefabrication of the ZnO nanoparticles, the synthesis of MoS{sub 2} nanoflowers, and the fabrication of MoS{sub 2}@ZnO heterojunctions, in which ZnO nanoparticles were uniformly self-assembled on the MoS{sub 2} nanoflowers by utilizing polyethyleneimine as a binding agent. The photocatalytic activities of the composite samples were evaluated by monitoring the photodegradation of methylene blue (MB). Compared with pure MoS{sub 2} nanoflowers, the composites show higher adsorption capability in dark and better photocatalytic efficiency due to the increased specific surface area and improved electron-hole pair separation. After irradiation for 100?min, the remaining MB in solution is about 7.3%. Moreover, the MoS{sub 2}@ZnO heterojunctions possess enhanced field emission properties with lower turn-on field of 3.08?V ?m{sup ?1}and lower threshold field of 6.9?V ?m{sup ?1} relative to pure MoS{sub 2} with turn-on field of 3.65?V ?m{sup ?1} and threshold field of 9.03?V ?m{sup ?1}.

  7. Study of structure of the TiO{sub 2}MoO{sub 3} bilayer films by Raman spectroscopy

    SciTech Connect (OSTI)

    Santos, Elias de Barros; Sigoli, Fernando Aparecido; Mazali, Italo Odone

    2014-12-15

    Highlights: TiO{sub 2}MoO{sub 3} bilayer thin films were easily prepared by dip-coating technique. Ti and Mo metallo-organic compounds were used as source of its respective oxide. TiO{sub 2} in anatase phase and orthorhombic phase of ?-MoO{sub 3} were identified. The bilayer structure was investigated by Raman spectroscopy. - Abstract: In this work, TiO{sub 2}MoO{sub 3} films were easily prepared by dip-coating technique and metallo-organic decomposition process (MOD). Raman analyses indicate the formation of TiO{sub 2} in anatase phase and orthorhombic phase of ?-MoO{sub 3}. It was observed that the Raman bands intensities attributed to TiO{sub 2} and MoO{sub 3} oxides were dependent on the number of decompositiondeposition cycles (DDC). The different number of DDC generates films with different thicknesses and the Raman signal was sensitive to this variation. Raman analyses provided qualitative information about the bilayer structure of the bi-component TiO{sub 2}MoO{sub 3} films, which was confirmed by scanning electron microscopy. In this direction, the dip-coating technique and MOD process can be an efficient strategy to facile preparation of many samples to be used in applications.

  8. Electron scattering mechanisms in Cu-Mn films for interconnect applications

    SciTech Connect (OSTI)

    Misjk, F.; Nagy, K. H.; Radnczi, G.; Lobotka, P.

    2014-08-28

    Electrical properties and corresponding structural features of Cu-Mn alloy films with potential application as barrier and interconnect layers were studied. Cu-Mn films were deposited by DC magnetron sputtering at room temperature on SiO{sub 2} substrates. Electrical resistivity measurements were made as a function of film composition and temperature. The specific resistivity varies linearly with the Mn content showing a maximum of 205???cm at 80 at. % Mn. The temperature coefficient of resistance (TCR) of all alloy films is low, showing non-metallic conductivity for most compositions. Also a minimum TCR has been observed in the 4080 at. % Mn range which was attributed to a magnetic transformation around 200300?K. Electrical resistivity measurements are correlated with the film structure revealed by transmission electron microscopy to clarify the phase regions throughout the composition range. In the 2040 at. % and 7080 at. % Mn ranges, two-phase structures were identified, where Cu- or Mn-rich solid solution grains were surrounded by a thin amorphous covering layer. Based on the revealed phase regions and morphologies electron scattering mechanisms in the system were evaluated by combining the Matthiessen's rule and the Mayadas-Schatzkes theory. Grain boundary reflectivity coefficients (r?=?0.60.8) were calculated from fitting the model to the measurements. The proposed model indicates that, in a binary system, the special arrangement of the two phases results in new scattering mechanisms. The results are of value in optimizing the various parameters needed to produce a suitable barrier layer.

  9. Synthesis of spherical LiMnPO{sub 4}/C composite microparticles

    SciTech Connect (OSTI)

    Bakenov, Zhumabay; Taniguchi, Izumi

    2011-08-15

    Highlights: {yields} We could prepare LiMnPO{sub 4}/C composites by a novel preparation method. {yields} The LiMnPO{sub 4}/C composites were spherical particles with a mean diameter of 3.65 {mu}m. {yields} The LiMnPO{sub 4}/C composite cathode exhibited 112 mAh g{sup -1} at 0.05 C. {yields} It also showed a good rate capability up to 5 C at room temperature and 55 {sup o}C. -- Abstract: Spherical LiMnPO{sub 4}/C composite microparticles were prepared by a combination of spray pyrolysis and spray drying followed by heat treatment and examined as a cathode material for lithium batteries. The structure, morphology and electrochemical performance of the resulting spherical LiMnPO{sub 4}/C microparticles were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electronic microscopy and standard electrochemical techniques. The final sample was identified as a single phase orthorhombic structure of LiMnPO{sub 4} and spherical powders with a geometric mean diameter of 3.65 {mu}m and a geometric standard deviation of 1.34. The electrochemical cells contained the spherical LiMnPO{sub 4}/C microparticles exhibited first discharge capacities of 112 and 130 mAh g{sup -1} at 0.05 C at room temperature and 55 {sup o}C, respectively. These also showed a good rate capability up to 5 C at room temperature and 55 {sup o}C.

  10. Theoretical study on strain induced variations in electronic properties of 2H-MoS{sub 2} bilayer sheets

    SciTech Connect (OSTI)

    Dong, Liang; Dongare, Avinash M.; Namburu, Raju R.; O'Regan, Terrance P.; Dubey, Madan

    2014-02-03

    The strain dependence of the electronic properties of bilayer sheets of 2H-MoS{sub 2} is studied using ab initio simulations based on density functional theory. An indirect band gap for bilayer MoS{sub 2} is observed for all variations of strain along the basal plane. Several transitions for the indirect band gap are observed for various strains for the bilayer structure. The variation of the band gap and the carrier effective masses for the holes and the electrons for the bilayer MoS{sub 2} structure under conditions of uniaxial strain, biaxial strain, as well as uniaxial stress is investigated.

  11. Mn-Stabilized Zirconia: From Imitation Diamonds to a New Potential High-T{sub C} Ferromagnetic Spintronics Material

    SciTech Connect (OSTI)

    Ostanin, S.; Ernst, A.; Sandratskii, L. M.; Bruno, P.; Daene, M.; Hergert, W.; Mertig, I.; Hughes, I. D.; Staunton, J. B.; Kudrnovsky, J.

    2007-01-05

    From the basis of ab initio electronic structure calculations which include the effects of thermally excited magnetic fluctuations, we predict Mn-stabilized cubic zirconia to be ferromagnetic above 500 K. We find this material, which is well known both as an imitation diamond and as a catalyst, to be half-metallic with the majority and minority spin Mn impurity states lying in zirconia's wide gap. The Mn concentration can exceed 40%. The high-T{sub C} ferromagnetism is robust to oxygen vacancy defects and to how the Mn impurities are distributed on the Zr fcc sublattice. We propose this ceramic as a promising future spintronics material.

  12. Properties of Ga{sub 1-x}Mn{sub x}As with high x (>0.1)

    SciTech Connect (OSTI)

    Chiba, D.; Yu, K. M.; Walukiewicz, W.; Nishitani, Y.; Matsukura, F.; Ohno, H.

    2008-04-01

    We have investigated the magnetic and the crystalline properties of a set of Ga{sub 1-x}Mn{sub x}As layers with high nominal Mn compositions (x=0.101-0.198). Magnetization measurements and combined channeling Rutherford backscattering (c-RBS) and particle induced x-ray emission (c-PIXE) measurements have been performed to determine the effective Mn composition x{sub eff} and the fraction of Mn atoms at various lattice sites. Here, x{sub eff} determined from magnetization measurements, which increases with increasing x, is consistent with the results determined from c-RBS-PIXE measurements.

  13. Enhanced ferromagnetic order in Sr{sub 4}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} featuring canted [MnO{sub 4}]{sub ?} spin chains of mixed-valent Mn(III)/Mn(IV). Aliovalent substitution of the Sr{sub 4?x}Ln{sub x}Mn{sup III}{sub 2+x}Mn{sup IV}{sub 1?x}O{sub 3}(GeO{sub 4}){sub 3} solid-solution

    SciTech Connect (OSTI)

    West, J. Palmer; Sulejmanovic, Dino; Becht, Gregory; He, Jian; Hitchcock, Dale; Yan, Yonggao; Hwu, Shiou-Jyh

    2013-10-15

    Crystals of Sr{sub 4?x}Ln{sub x}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} (x=0; x?0.15 for Ln=La, Pr, Nd, Sm. Eu, Gd, Dy; x?0.3 for Ln=Gd) were isolated upon using high-temperature, solid-state methods in molten-salt media. These compounds are isostructural with the previously reported Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3} (Ln=La, Sm, Gd) series that contains the same [MnO{sub 4}]{sub ?} spin chains. The synthesis of the Sr{sub 4}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} (x=0) phase was carried out by a double aliovalent substitution with respect to the Sr{sup 2+} and Ge{sup 4+} ions that replace Na{sup +}/Ln{sup 3+} and As{sup 5+} in Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3}, respectively. The title series contains mixed-valent Mn(III)/Mn(IV) and shows a limited range of solid solution, both of which were not observed in the previously reported Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3} series. To form the Sr{sub 4?x}Ln{sub x}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} solid solution, one of the Sr{sup 2+} sites, i.e., the original Ln-site in Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3}, is partially substituted by Ln{sup 3+} in a statistical disorder of Sr{sub 1?x}/Ln{sub x}. Initial magnetic investigations of selected derivatives reveal higher ferromagnetic ordering temperatures than those reported for the Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3} series, presumably attributed to a lesser degree of canting as a result of introducing non-JahnTeller Mn{sup 4+} ions. Also intriguing is the observation of multiple anomalies at low temperatures which appear to be of electronic origins. - Graphical abstract: Sr{sub 4?x}Ln{sub x}Mn(III){sub 2+x}Mn(IV){sub 1?x}O{sub 3}(GeO{sub 4}){sub 3}. Display Omitted - Highlights: Double aliovalent substitution: Sr{sub 4}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} with respect to Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3}. Solid solution with respect to statistical disorder of Sr{sub 1?x}Ln{sub x} in one of the two Sr sites. Mn{sup 3+}/Mn{sup 4+} magnetic ions are spatially arranged in a triangular kagom fashion. Enhanced ferromagnetic ordering attributed to doping non-JahnTeller Mn{sup 4+}.

  14. AMoRE: Collaboration for searches for the neutrinoless double-beta decay of the isotope of {sup 100}Mo with the aid of {sup 40}Ca{sup 100}MoO{sub 4} as a cryogenic scintillation detector

    SciTech Connect (OSTI)

    Khanbekov, N. D., E-mail: xanbekov@gmail.com [Institute of Theoretical and Experimental Physics (Russian Federation)

    2013-09-15

    The AMoRE (Advanced Mo based Rare process Experiment) Collaboration is planning to employ {sup 40}Ca{sup 100}MoO{sub 4} single crystals as a cryogenic Scintillation detector for studying the neutrinoless double-beta decay of the isotope {sup 100}Mo. A simultaneous readout of phonon and scintillation signals is performed in order to suppress the intrinsic background. The planned sensitivity of the experiment that would employ 100 kg of {sup 40}Ca{sup 100}MoO{sub 4} over five years of data accumulation would be T{sub 1/2}{sup 0{nu}} = 3 Multiplication-Sign 10{sup 26} yr, which corresponds to values of the effective Majorana neutrino mass in the range of Left-Pointing-Angle-Bracket m{sub {nu}} Right-Pointing-Angle-Bracket {approx} 0.02-0.06 eV.

  15. Comparison of LiMnPO4 made by Combustion and Hydrothermal Syntheses

    SciTech Connect (OSTI)

    Chen, Jiajun; Doeff, Marca M.; Wang, Ruigang

    2008-05-15

    Among the olivine-structured metal phosphate family, LiMnPO{sub 4} exhibits a high discharge potential (4V), which is still compatible with common electrolytes, making it interesting for use in the next generation of Li ion batteries. The extremely low electronic conductivity of this material severely limits its electrochemical performance, however. One strategy to overcome this limitation is to make LiMnPO{sub 4} nanoparticulate to decrease the diffusion distance. Another is to add a carbon or other conductive coating in intimate contact with the nanoparticles of the main phase, as is commonly done with LiFePO{sub 4}. The electrochemical performance of LiFePO{sub 4} is highly dependent on the quality of the carbon coatings on the particles [1-2], among other variables. Combustion synthesis allows the co-synthesis of nanoparticles coated with carbon in one step. Hydrothermal synthesis is used industrially to make LiFePO{sub 4} cathode materials [3] and affords a good deal of control over purity, crystallinity, and particle size. A wide range of olivine-structured materials has been successfully prepared by this technique [4], including LiMnPO{sub 4} in this study. In this paper, we report on the new synthesis of nano-LiMnPO{sub 4} by a combustion method. The purity is dependent upon the conditions used for synthesis, including the type of fuel and precursors that are chosen. The fuel to nitrate ratio influences the combustion temperature, which determines the type and amount of carbon found in the LiMnPO{sub 4} composites. This can further be modified by use of carbon structural modifiers added during a subsequent (optional) calcination step. Figure 1 shows a transmission electron microscopy (TEM) image of the spherical nano-sized LiMnPO{sub 4} particles typically formed by combustion synthesis. The average particle size is around 30 nm, in agreement with values obtained by the Rietveld refinement of XRD patterns. The small size of the particles cause the peak broadening evident in the pattern of combustion formed LiMnPO{sub 4}, shown in Figure 2. Figure 2 also shows a pattern of hydrothermally prepared LiMnPO{sub 4}, which is sub-micron in size. In this presentation, we will show how the crystallographic parameters, particle size, particle morphology, and carbon content and structure impact the electrochemical properties of the LiMnPO{sub 4}/C composites produced by these methods.

  16. Comparison of LiMnPO4 made by Combustion and Hydrothermal Syntheses

    SciTech Connect (OSTI)

    Chen, Jiajun; Doeff, Marca M.; Wang, Ruigang

    2008-10-12

    Among the olivine-structured metal phosphate family, LiMnPO{sub 4} exhibits a high discharge potential (4V), which is still compatible with common electrolytes, making it interesting for use in the next generation of Li ion batteries. The extremely low electronic conductivity of this material severely limits its electrochemical performance, however. One strategy to overcome this limitation is to make LiMnPO{sub 4} nanoparticulate to decrease the diffusion distance. Another is to add a carbon or other conductive coating in intimate contact with the nanoparticles of the main phase, as is commonly done with LiFePO{sub 4}. The electrochemical performance of LiFePO{sub 4} is highly dependent on the quality of the carbon coatings on the particles, among other variables. Combustion synthesis allows the co-synthesis of nanoparticles coated with carbon in one step. Hydrothermal synthesis is used industrially to make LiFePO{sub 4} cathode materials and affords a good deal of control over purity, crystallinity, and particle size. A wide range of olivine-structured materials has been successfully prepared by this technique, including LiMnPO{sub 4} in this study. In this paper, we report on the new synthesis of nano-LiMnPO{sub 4} by a combustion method. The purity is dependent upon the conditions used for synthesis, including the type of fuel and precursors that are chosen. The fuel to nitrate ratio influences the combustion temperature, which determines the type and amount of carbon found in the LiMnPO{sub 4} composites. This can further be modified by use of carbon structural modifiers added during a subsequent (optional) calcination step. Figure 1 shows a transmission electron microscopy (TEM) image of the spherical nano-sized LiMnPO{sub 4} particles typically formed by combustion synthesis. The average particle size is around 30 nm, in agreement with values obtained by the Rietveld refinement of XRD patterns. The small size of the particles cause the peak broadening evident in the pattern of combustion formed LiMnPO{sub 4}, shown in Figure 2. Figure 2 also shows a pattern of hydrothermally prepared LiMnPO{sub 4}, which is sub-micron in size. In this presentation, we will show how the crystallographic parameters, particle size, particle morphology, and carbon content and structure impact the electrochemical properties of the LiMnPO{sub 4}/C composites produced by these methods.

  17. Disorder dependent half-metallicity in Mn{sub 2}CoSi inverse Heusler alloy

    SciTech Connect (OSTI)

    Singh, Mukhtiyar; Saini, Hardev S.; Thakur, Jyoti; Reshak, Ali H.; Kashyap, Manish K.

    2013-12-15

    Heusler alloys based thin-films often exhibit a degree of atomic disorder which leads to the lowering of spin polarization in spintronic devices. We present ab-initio calculations of atomic disorder effects on spin polarization and half-metallicity of Mn{sub 2}CoSi inverse Heusler alloy. The five types of disorder in Mn{sub 2}CoSi have been proposed and investigated in detail. The A2{sub a}-type and B2-type disorders destroy the half-metallicity whereas it sustains for all disorders concentrations in DO{sub 3a}- and A2{sub b}-type disorder and for smallest disorder concentration studied in DO{sub 3b}-type disorder. Lower formation energy/atom for A2{sub b}-type disorder than other four disorders in Mn{sub 2}CoSi advocates the stability of this disorder. The total magnetic moment shows a strong dependence on the disorder and the change in chemical environment. The 100% spin polarization even in the presence of disorders explicitly supports that these disorders shall not hinder the use of Mn{sub 2}CoSi inverse Heusler alloy in device applications. - Graphical abstract: Minority-spin gap (E{sub g↓}) and HM gap (E{sub sf}) as a function of concentrations of various possible disorder in Mn{sub 2}CoSi inverse Heusler alloy. The squares with solid line (black color)/dotted line (blue color)/dashed line (red color) reperesents E{sub g↓} for DO{sub 3a}-/DO{sub 3b}-/A2{sub b}-type disorder in Mn{sub 2}CoSi and the spheres with solid line (black color)/dottedline (blue color)/dashed line (red color) represents E{sub sf} for DO{sub 3a}-/DO{sub 3b}-/A2{sub b}-type disorder in Mn{sub 2}CoSi. - Highlights: • The DO{sub 3}- and A2-type disorders do not affect the half-metallicity in Mn{sub 2}CoSi. • The B2-type disorder solely destroys half-metallicity in Mn{sub 2}CoSi. • The A2-type disorder most probable to occur out of all three types. • The total spin magnetic moment strongly depends on the disorder concentrations.

  18. Novel Solar Energy Conversion Materials by Design of Mn(II) Oxides

    SciTech Connect (OSTI)

    Lany, S.; Peng, H.; Ndione, P.; Zakutayev, A.; Ginley, D. S.

    2013-01-01

    Solar energy conversion materials need to fulfill simultaneously a number of requirements in regard of their band-structure, optical properties, carrier transport, and doping. Despite their desirable chemical properties, e.g., for photo-electrocatalysis, transition-metal oxides usually do not have desirable semiconducting properties. Instead, oxides with open cation d-shells are typically Mott or charge-transfer insulators with notoriously poor transport properties, resulting from large effective electron/hole masses or from carrier self-trapping. Based on the notion that the electronic structure features (p-d interaction) supporting the p-type conductivity in d10 oxides like Cu2O and CuAlO2 occurs in a similar fashion also in the d5 (high-spin) oxides, we recently studied theoretically the band-structure and transport properties of the prototypical binary d5 oxides MnO and Fe2O3 [PRB 85, 201202(R)]. We found that MnO tends to self-trap holes by forming Mn+III, whereas Fe2O3 self-traps electrons by forming Fe+II. However, the self-trapping of holes is suppressed by when Mn is tetrahedrally coordinated, which suggests specific routes to design novel solar conversion materials by considering ternary Mn(II) oxides or oxide alloys. We are presenting theory, synthesis, and initial characterization for these novel energy materials.

  19. High-Resolution Structure of the Photosynthetic Mn4Ca Catalyst from X-ray Spectroscopy

    SciTech Connect (OSTI)

    Yachandra, Vittal; Yano, Junko; Kern, Jan; Pushkar, Yulia; Sauer, Kenneth; Glatzel, Pieter; Bergmann, Uwe; Messinger, Johannes; Zouni, Athina; Yachandra, Vittal K.

    2007-08-01

    The application of high-resolution X-ray spectroscopy methods to study the photosynthetic water oxidizing complex, which contains a unique hetero-nuclear catalytic Mn4Ca cluster, are described. Issues of X-ray damage especially at the metal sites in the Mn4Ca cluster are discussed. The structure of the Mn4Ca catalyst at high-resolution which has so far eluded attempts of determination by X-ray diffraction, EXAFS and other spectroscopic techniques has been addressed using polarized EXAFS techniques applied to oriented PS II membrane preparations and PS II single crystals. A review of how the resolution of traditional EXAFS techniques can be improved, using methods such as range-extended EXAFS is presented, and the changes that occur in the structure of the cluster as it advances through the catalytic cycle are described. X-ray absorption and emission techniques (XANES and K? emission) have been used earlier to determine the oxidation states of the Mn4Ca cluster, and in this report we review the use of X-ray resonant Raman spectroscopy to understand the electronic structure of the Mn4Ca cluster as it cycles through the intermediate S-states.

  20. Microstructure evolution in solution treated Ti15Mo alloy processed by high pressure torsion

    SciTech Connect (OSTI)

    Jane?ek, Milo; ?ek, Jakub; Strsk, Josef; Vclavov, Kristna; Hruka, Petr; Polyakova, Veronika; Gatina, Svetlana; Semenova, Irina

    2014-12-15

    Microstructure evolution and mechanical properties of ultra-fine grained Ti15Mo alloy processed by high pressure torsion were investigated. High pressure torsion straining resulted in strong grain refinement as-observed by transmission electron microscopy. Microhardness and light microscopy showed two distinct regions (i) a central region with radial material flow and low microhardness (340 HV) and (ii) a peripheral region with rotational material flow and high microhardness (430 HV). Positron annihilation spectroscopy showed that the only detectable defects in the material are dislocations, whose density increases with the radial distance and the number of high pressure torsion revolutions. The local chemical environment around defects does not differ significantly from the average composition. - Highlights: Beta-Ti alloy Ti15Mo was processed by high pressure torsion (HPT). Lateral inhomogeneity of the microstructure and microhardness was found. Dislocations are the only lattice defects detectable by positron annihilation. Molybdenum is not preferentially segregated along dislocation cores.

  1. LANL Experience Rolling Zr-Clad LEU-10Mo Foils for AFIP-7

    SciTech Connect (OSTI)

    Hammon, Duncan L.; Clarke, Kester D.; Alexander, David J.; Kennedy, Patrick K.; Edwards, Randall L.; Duffield, Andrew N.; Dombrowski, David E.

    2015-05-29

    The cleaning, canning, rolling and final trimming of Low Enriched Uranium-10 wt. pct. Molybdenum (LEU-10Mo) foils for ATR (Advanced Test Reactor) fuel plates to be used in the AFIP-7 (ATR Full Size Plate In Center Flux Trap Position) experiments are summarized. Six Zr-clad foils were produced from two LEU-10Mo castings supplied to Los Alamos National Laboratory (LANL) by Y-12 National Security Complex. Details of cleaning and canning procedures are provided. Hot- and cold-rolling results are presented, including rolling schedules, images of foils in-process, metallography and local compositions of regions of interest, and details of final foil dimensions and process yield. This report was compiled from the slides for the presentation of the same name given by Duncan Hammon on May 12, 2011 at the AFIP-7 Lessons Learned meeting in Salt Lake City, UT, with Los Alamos National Laboratory document number LA-UR 11-02898.

  2. Co-Rolled U10Mo/Zirconium-Barrier-Layer Monolithic Fuel Foil Fabrication Process

    SciTech Connect (OSTI)

    G. A. Moore; M. C. Marshall

    2010-01-01

    Integral to the current UMo fuel foil processing scheme being developed at Idaho National Laboratory (INL) is the incorporation of a zirconium barrier layer for the purpose of controlling UMo-Al interdiffusion at the fuel-meat/cladding interface. A hot co-rolling process is employed to establish a ~25-m-thick zirconium barrier layer on each face of the ~0.3-mm-thick U10Mo fuel foil.

  3. NNSA Works to Establish a Reliable Supply of Mo-99 Produced Without Highly

    National Nuclear Security Administration (NNSA)

    Enriched Uranium | National Nuclear Security Administration Works to Establish a Reliable Supply of Mo-99 Produced Without Highly Enriched Uranium | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Countering Nuclear Terrorism About Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations

  4. Tribological properties of self-lubricating NiAl/Mo-based composites containing AgVO{sub 3} nanowires

    SciTech Connect (OSTI)

    Liu, Eryong; Gao, Yimin; Bai, Yaping; Yi, Gewen; Wang, Wenzhen; Zeng, Zhixiang; Jia, Junhong

    2014-11-15

    Silver vanadate (AgVO{sub 3}) nanowires were synthesized by hydrothermal method and self-lubricating NiAl/Mo-AgVO{sub 3} composites were fabricated by powder metallurgy technique. The composition and microstructure of NiAl/Mo-based composites were characterized and the tribological properties were investigated from room temperature to 900 C. The results showed that NiAl/Mo-based composites were consisted of nanocrystalline B2 ordered NiAl matrix, Al{sub 2}O{sub 3}, Mo{sub 2}C, metallic Ag and vanadium oxide phase. The appearance of metallic Ag and vanadium oxide phase can be attributed to the decomposition of AgVO{sub 3} during sintering. Wear testing results confirmed that NiAl/Mo-based composites have excellent tribological properties over a wide temperature range. For example, the friction coefficient and wear rate of NiAl/Mo-based composites containing AgVO{sub 3} were significantly lower than the composites containing only metallic Mo or AgVO{sub 3} lubricant when the temperature is above 300 C, which can be attributed to the synergistic lubricating action of metallic Mo and AgVO{sub 3} lubricants. Furthermore, Raman results indicated that the composition on the worn surface of NiAl-based composites was self-adjusted after wear testing at different temperatures. For example, Ag{sub 3}VO{sub 4} and Fe{sub 3}O{sub 4} lubricants were responsible for the improvement of tribological properties at 500 C, AgVO{sub 3}, Ag{sub 3}VO{sub 4} and molybdate for 700 C, and AgVO{sub 3} and molybdate for 900 C of NiAl-based composites with the addition of metallic Mo and AgVO{sub 3}. - Highlights: NiAl/Mo-AgVO{sub 3} nanocomposites were prepared by mechanical alloying and sintering. AgVO{sub 3} decomposed to metallic Ag and vanadium oxide during the sintering process. NiAl/Mo-AgVO{sub 3} exhibited superior tribological properties at a board temperature range. Phase composition on the worn surface was varied with temperatures. Self-adjusted action was responsible for the improvement of tribological properties.

  5. Study on Shielding Requirements for Radioactive Waste Transportation in a Mo-99 Production Plant - 13382

    SciTech Connect (OSTI)

    Melo Rego, Maria Eugenia de; Kazumi Sakata, Solange; Vicente, Roberto; Hiromoto, Goro [Nuclear and Energy Research Institute, IPEN-CNEN/SP (Brazil)] [Nuclear and Energy Research Institute, IPEN-CNEN/SP (Brazil)

    2013-07-01

    Brazil is currently planning to produce {sup 99}Mo from fission of low enriched uranium (LEU) targets. The planned end of irradiation activity of {sup 99}Mo is about 185 TBq (5 kCi) per week to meet the present domestic demand of {sup 99m}Tc generators. The radioactive wastes from the production plant will be transferred to a waste treatment facility at the same site. The total activity of the actinides, fission and activation products present in the wastes can be predicted based on the yields of fission and activation data for the irradiation conditions, such as composition and mass of uranium targets, irradiation time, neutron flux, production schedule, etc., which were in principle already established by the project management. The transportation of the wastes from the production plant to the treatment facility will be done by means of special shielded packages. An assessment of the shielding required for the packages has been done and the results are presented here, aiming at contributing to the design of the waste management facility for the {sup 99}Mo production plant. (authors)

  6. Exciton-dominated dielectric function of atomically thin MoS2 films

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

    Yu, Yiling; Yu, Yifei; Cai, Yongqing; Li, Wei; Gurarslan, Alper; Peelaers, Hartwin; Aspnes, David E.; Van de Walle, Chris G.; Nguyen, Nhan V.; Zhang, Yong -Wei; et al

    2015-11-24

    We systematically measure the dielectric function of atomically thin MoS2 films with different layer numbers and demonstrate that excitonic effects play a dominant role in the dielectric function when the films are less than 5–7 layers thick. The dielectric function shows an anomalous dependence on the layer number. It decreases with the layer number increasing when the films are less than 5–7 layers thick but turns to increase with the layer number for thicker films. We show that this is because the excitonic effect is very strong in the thin MoS2 films and its contribution to the dielectric function maymore » dominate over the contribution of the band structure. We also extract the value of layer-dependent exciton binding energy and Bohr radius in the films by fitting the experimental results with an intuitive model. The dominance of excitonic effects is in stark contrast with what reported at conventional materials whose dielectric functions are usually dictated by band structures. Lastly, the knowledge of the dielectric function may enable capabilities to engineer the light-matter interactions of atomically thin MoS2 films for the development of novel photonic devices, such as metamaterials, waveguides, light absorbers, and light emitters.« less

  7. Electrical properties of a-C:Mo films produced by dual-cathode filtered cathodic arc plasma deposition

    SciTech Connect (OSTI)

    Sansongsiri, Sakon; Anders, Andre; Yodsombat, Banchob

    2008-01-20

    Molybdenum-containing amorphous carbon (a-C:Mo) thin films were prepared using a dual-cathode filtered cathodic arc plasma source with a molybdenum and a carbon (graphite) cathode. The Mo content in the films was controlled by varying the deposition pulse ratio of Mo and C. Film sheet resistance was measured in situ at process temperature, which was close to room temperature, as well as ex situ as a function of temperature (300-515 K) in ambient air. Film resistivity and electrical activation energy were derived for different Mo and C ratios and substrate bias. Film thickness was in the range 8-28 nm. Film resistivity varied from 3.55x10-4 Omega m to 2.27x10-6 Omega m when the Mo/C pulse ratio was increased from 0.05 to 0.4, with no substrate bias applied. With carbon-selective bias, the film resistivity was in the range of 4.59x10-2 and 4.05 Omega m at a Mo/C pulse ratio of 0.05. The electrical activation energy decreased from 3.80x10-2 to 3.36x10-4 eV when the Mo/C pulse ratio was increased in the absence of bias, and from 0.19 to 0.14 eV for carbon-selective bias conditions. The resistivity of the film shifts systematically with the amounts of Mo and upon application of substrate bias voltage. The intensity ratio of the Raman D-peak and G-peak (ID/IG) correlated with the pre-exponential factor (sigma 0) which included charge carrier density and density of states.

  8. Superconducting and structural properties of {delta}-MoC{sub 0.681} cubic molybdenum carbide phase

    SciTech Connect (OSTI)

    Sathish, C.I. [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan) [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Guo, Yanfeng, E-mail: GUO.Yanfeng@nims.go.jp [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Wang, Xia [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan) [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Tsujimoto, Yoshihiro [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Li, Jun [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan) [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Zhang, Shoubao [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Matsushita, Yoshitaka [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan)] [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan); Shi, Youguo; Tian, Huanfang; Yang, Huaixin; Li, Jianqi [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)] [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yamaura, Kazunari, E-mail: YAMAURA.Kazunari@nims.go.jp [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan) [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2012-12-15

    The superconducting and lattice properties of {delta}-MoC{sub 0.681} were studied by electromagnetic measurements, synchrotron X-ray diffraction, neutron diffraction, and electron diffraction. The superconducting properties (T{sub c}=12 K) of {delta}-MoC{sub 0.681} were well characterized by a weak coupling model. The carbon vacancies present in the host cubic structure were found to be robust, although the material was synthesized from stoichiometric carbon and Mo powder under a high-pressure of 6 GPa. A thermodynamically-stable structure with ordered vacancies did not account for the robust features of {delta}-MoC{sub 0.681} since the vacancies are unlikely to be ordered in long range in the host structure. A model based on inherent phonon instability theoretically predicted for a stoichiometric MoC phase might be responsible for the robust features of {delta}-MoC{sub 0.681}. - Graphical Abstract: The cubic molybdenum carbide shows an excellent superconductivity with robust carbon vacancies. Inherent phonon instability theoretically predicted for a stoichiometric MoC phase might be responsible for the vacancies rather than a thermodynamically-stable structure with vacancies ordering. Highlights: Black-Right-Pointing-Pointer The 12 K superconductivity is well characterized by a weakly coupling model. Black-Right-Pointing-Pointer Carbon vacancies are robust and disordered in the cubic host structure. Black-Right-Pointing-Pointer Inherent phonon instability might be responsible for the robust carbon vacancies in {delta}-MoC{sub 0.681}.

  9. Elasticity and magnetocaloric effect in MnFe4Si3

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

    Herlitschke, Marcus; Klobes, B.; Sergueev, I.; Hering, Paul; Persson, Joerg; Hermann, Raphael P.

    2016-03-16

    The room temperature magnetocaloric material MnFe4Si3 was investigated with nuclear inelastic scattering (NIS) and resonant ultrasound spectroscopy (RUS) at different temperatures and applied magnetic fields in order to assess the infuence of the magnetic transition and the magnetocaloric effect on the lattice dynamics. The NIS data give access to phonons with energies above 3 meV, whereas RUS probes the elasticity of the material in the MHz frequency range and thus low energy, ~5 neV, phonon modes. A significant infuence of the magnetic transition on the lattice dynamics is observed only in the low energy region. Here, MnFe4Si3 and other compoundsmore » in the Mn5-xFexSi3 series were also investigated with vibrating sample magnetometry, resistivity measurements and Moessbauer spectroscopy in order to study the magnetic transitions and to complement the obtained results on the lattice dynamics.« less

  10. Electronic structural and magnetic properties of Mn{sub 5}Ge{sub 3} clusters

    SciTech Connect (OSTI)

    Yuan, H. K.; Chen, H. Kuang, A. L.; Tian, C. L.; Wang, J. Z.

    2013-11-28

    Theoretical understanding of the stability, ferromagnetism, and spin polarization of Mn{sub 5}Ge{sub 3} clusters has been performed by using the density functional theory with generalized gradient approximation for exchange and correlation. The magnetic moments and magnetic anisotropy energy (MAE) have been calculated for both bulk and clusters, and the enhanced magnetic moment as well as the enlarged MAE have been identified in clusters. The most attractive achievement is that Mn{sub 5}Ge{sub 3} clusters show a fine half-metallic character with large energy scales. The present results may have important implications for potential applications of small Mn{sub 5}Ge{sub 3} clusters as both emerging spintronics and next-generation data-storage technologies.

  11. Anomalous magnetic configuration of Mn{sub 2}NiAl ribbon and the role of hybridization in the martensitic transformation of Mn{sub 50}Ni{sub 50−x}Al{sub x} ribbons

    SciTech Connect (OSTI)

    Zhao, R. B.; Zhao, D. W.; Li, G. K.; Ma, L. E-mail: houdenglu@mail.hebtu.edu.cn; Zhen, C. M.; Hou, D. L. E-mail: houdenglu@mail.hebtu.edu.cn; Wang, W. H.; Liu, E. K.; Chen, J. L.; Wu, G. H.

    2014-12-08

    The magnetic configuration of Mn{sub 2}NiAl ribbon has been investigated. In contrast to Ni{sub 2}MnAl, the compound Mn{sub 2}NiAl with considerable disorder does exhibit ferromagnetism and, due to exchange interaction competition, both ferromagnetic and antiferromagnetic moment orientations can coexist between nearest neighbor Mn atoms. This is unexpected in Heusler alloys. Regarding the mechanism of the martensitic transformation in Mn{sub 50}Ni{sub 50−x}Al{sub x}, it is found that increasing the Al content results in an unusual change in the lattice constant, a decrease of the transformation entropy change, and enhancement of the calculated electron localization. These results indicate that the p-d covalent hybridization between Mn (or Ni) and Al atoms gradually increases at the expense of the d-d hybridization between Ni and Mn atoms. This leads to an increased stability of the austenite phase and a decrease of the martensitic transformation temperature. For 11 ≤ x ≤ 14, Mn{sub 50}Ni{sub 50−x}Al{sub x} ferromagnetic shape memory alloys are obtained.

  12. OPTICAL AND NEAR-INFRARED POLARIMETRY OF HIGHLY REDDENED Type Ia SUPERNOVA 2014J: PECULIAR PROPERTIES OF DUST IN M82

    SciTech Connect (OSTI)

    Kawabata, K. S.; Akitaya, H.; Itoh, R.; Moritani, Y. [Hiroshima Astrophysical Science Center, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Yamanaka, M. [Department of Physics, Faculty of Science and Engineering, Konan University, Okamoto, Kobe, Hyogo 658-8501 (Japan); Maeda, K.; Nogami, D. [Department of Astronomy, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Ui, T.; Kawabata, M.; Mori, K.; Takaki, K.; Ueno, I.; Chiyonobu, S.; Harao, T.; Matsui, R.; Miyamoto, H.; Nagae, O. [Department of Physical Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); Nomoto, K.; Suzuki, N. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Tanaka, M., E-mail: kawabtkj@hiroshima-u.ac.jp [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); and others

    2014-11-01

    We present optical and near-infrared multi-band linear polarimetry of the highly reddened Type Ia supernova (SN) 2014J that appeared in M82. SN 2014J exhibits large polarization at shorter wavelengths, e.g., 4.8% in the B band, which decreases rapidly at longer wavelengths, while the position angle of the polarization remains at approximately 40 over the observed wavelength range. These polarimetric properties suggest that the observed polarization is likely predominantly caused by the interstellar dust within M82. Further analysis shows that the polarization peaks at a wavelengths much shorter than those obtained for the Galactic dust. The wavelength dependence of the polarization can be better described by an inverse power law rather than by the Serkowski law for Galactic interstellar polarization. These points suggest that the nature of the dust in M82 may be different from that in our Galaxy, with polarizing dust grains having a mean radius of <0.1 ?m.

  13. Low-frequency 1/f noise in MoS{sub 2} transistors: Relative contributions of the channel and contacts

    SciTech Connect (OSTI)

    Renteria, J.; Jiang, C.; Samnakay, R.; Rumyantsev, S. L.; Goli, P.; Balandin, A. A.; Shur, M. S.

    2014-04-14

    We report on the results of the low-frequency (1/f, where f is frequency) noise measurements in MoS{sub 2} field-effect transistors revealing the relative contributions of the MoS{sub 2} channel and Ti/Au contacts to the overall noise level. The investigation of the 1/f noise was performed for both as fabricated and aged transistors. It was established that the McWhorter model of the carrier number fluctuations describes well the 1/f noise in MoS{sub 2} transistors, in contrast to what is observed in graphene devices. The trap densities extracted from the 1/f noise data for MoS{sub 2} transistors, are 2??10{sup 19}?eV{sup ?1}cm{sup ?3} and 2.5??10{sup 20}?eV{sup ?1}cm{sup ?3} for the as fabricated and aged devices, respectively. It was found that the increase in the noise level of the aged MoS{sub 2} transistors is due to the channel rather than the contact degradation. The obtained results are important for the proposed electronic applications of MoS{sub 2} and other van der Waals materials.

  14. Preparation of Al{sub 2}O{sub 3}/Mo nanocomposite powder via chemical route and spray drying

    SciTech Connect (OSTI)

    Lo, M.; Cheng, F.; Wei, W.J.

    1996-08-01

    A route to prepare nanometer-sized Mo particulates in Al{sub 2}O{sub 3} was attempted by a combination of solution reactions in molecular scale and forcing precipitation by a spray-drying technique. MoO{sub 3} was first dissolved in ammonia water and then added in the slurry with high purity, submicrometer Al{sub 2}O{sub 3} powder. Mixed suspension was spray-dried, and then the dried granules were reduced by hydrogen gas and further hot-pressing to a bulky composite at various temperatures. Dissolution of Mo oxide, adsorption reactions on alumina surface, and surface potential of alumina particles in homogeneous ammonia suspension were studied. Characterization of the granules, including compactability, flowing properties, surface morphology, grain growth of Mo and Al{sub 2}O{sub 3}, and mixing homogeneity, were examined. Homogeneity of the spray-dried granules was determined by the calculation of mixing index and the observation of the microstructure of sintered body. The existence of intergranular, intragranular, and nanosized Mo particulates within Al{sub 2}O{sub 3} grains was observed by transmission electron microscopy (TEM). All the evidences revealed that homogeneous composites with nanometer-sized Mo had been successfully prepared by this attempt with the proposed chemical route and following spray-drying process. {copyright}{ital 1996 Materials Research Society.}

  15. Kinetic study of hydrogen evolution reaction on Ni{sub 30} Mo{sub 70}, Co{sub 30}Mo{sub 70}, Co{sub 30}Ni{sub 70} and Co{sub 10}Ni{sub 20}Mo{sub 70} alloy electrodes

    SciTech Connect (OSTI)

    Dominguez-Crespo, M.A.; Plata-Torres, M.; Torres-Huerta, A.M.; Arce-Estrada, E.M. . E-mail: earce@ipn.mx; Hallen-Lopez, J.M.

    2005-07-15

    The hydrogen evolution reaction on nanocrystalline Ni{sub 30}Mo{sub 70}, Co{sub 30}Mo{sub 70}, Co{sub 30}Ni{sub 70}, and Co{sub 10}Ni{sub 20}Mo{sub 70}, metallic powders prepared by mechanical alloying was investigated with linear polarization and ac impedance methods, in 30 wt.% KOH aqueous solution at room temperature. The formation process and structural properties of these nanocrystalline materials were characterized by X-ray diffraction and transmission electron microscopy. Alloyed powders showed the presence of two phases: an fcc solid solution and intermetallic compounds of Ni, Co and Mo. Based on polarization and ac impedance measurements, an improved electrocatalytic activity for hydrogen evolution reaction was observed in mechanically alloyed Co{sub 30}Ni{sub 70} powders, which is slightly higher than milled metallic Ni powders.

  16. Enhanced performance of branched TiO{sub 2} nanorod based Mn-doped CdS and Mn-doped CdSe quantum dot-sensitized solar cell

    SciTech Connect (OSTI)

    Kim, Soo-Kyoung; Gopi, Chandu V. V. M.; Lee, Jae-Cheol; Kim, Hee-Je

    2015-04-28

    TiO{sub 2} branched nanostructures could be efficient as photoanodes for quantum dot-sensitized solar cells (QDSCs) due to their large surface area for QD deposition. In this study, Mn-doped CdS/Mn-doped CdSe deposited branched TiO{sub 2} nanorods were fabricated to enhance the photovoltaic performance of QDSCs. Mn doping in CdS and CdSe retards the recombination losses of electrons, while branched TiO{sub 2} nanorods facilitate effective electron transport and compensate for the low surface area of the nanorod structure. As a result, the charge-transfer resistance (R{sub CT}), electron lifetime (?{sub e}), and the amount of QD deposition were significantly improved with branched TiO{sub 2} nanorod based Mn-doped CdS/Mn-doped CdSe quantum dot-sensitized solar cell.

  17. Structural transformations in Mn{sub 2}NiGa due to residual stress

    SciTech Connect (OSTI)

    Singh, Sanjay; Maniraj, M.; D'Souza, S. W.; Barman, S. R.; Ranjan, R.

    2010-02-22

    Powder x-ray diffraction study of Mn{sub 2}NiGa ferromagnetic shape memory alloy shows the existence of a 7M monoclinic modulated structure at room temperature (RT). The structure of Mn{sub 2}NiGa is found to be highly dependent on residual stress. For higher stress, the structure is tetragonal at RT, and for intermediate stress it is 7M monoclinic. However, only when the stress is considerably relaxed, the structure is cubic, as is expected at RT since the martensitic transition temperature is 230 K.

  18. MnO spin-wave dispersion curves from neutron powder diffraction

    SciTech Connect (OSTI)

    Goodwin, Andrew L.; Dove, Martin T.; Tucker, Matthew G.; Keen, David A.

    2007-02-15

    We describe a model-independent approach for the extraction of spin-wave dispersion curves from powder neutron total scattering data. Our approach is based on a statistical analysis of real-space spin configurations to calculate spin-dynamical quantities. The RMCPROFILE implementation of the reverse Monte Carlo refinement process is used to generate a large ensemble of supercell spin configurations from MnO powder diffraction data collected at 100 K. Our analysis of these configurations gives spin-wave dispersion curves for MnO that agree well with those determined independently using neutron triple-axis spectroscopic techniques.

  19. In operando X-ray studies of the conversion reaction in Mn3O4 lithium

    Office of Scientific and Technical Information (OSTI)

    battery anodes (Journal Article) | SciTech Connect operando X-ray studies of the conversion reaction in Mn3O4 lithium battery anodes Citation Details In-Document Search Title: In operando X-ray studies of the conversion reaction in Mn3O4 lithium battery anodes Authors: Lowe, Michael A. ; Gao, Jie ; Abruña, Héctor D. Publication Date: 2013-01-01 OSTI Identifier: 1080663 DOE Contract Number: SC0001086 Resource Type: Journal Article Resource Relation: Journal Name: J. Mater. Chem. A; Journal

  20. Magnetoelectric coupling tuned by competing anisotropies in Mn 1 - x Ni x

    Office of Scientific and Technical Information (OSTI)

    TiO 3 (Journal Article) | DOE PAGES Magnetoelectric coupling tuned by competing anisotropies in Mn 1 - x Ni x TiO 3 « Prev Next » Title: Magnetoelectric coupling tuned by competing anisotropies in Mn 1 - x Ni x TiO 3 Authors: Chi, Songxue ; Ye, Feng ; Zhou, H. D. ; Choi, E. S. ; Hwang, J. ; Cao, Huibo ; Fernandez-Baca, Jaime A. Publication Date: 2014-10-24 OSTI Identifier: 1181043 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal

  1. Unoccupied electronic structure of Ni2MnGa ferromagnetic shape memory alloy

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

    Maniraj, M.; D׳Souza, S. W.; Rai, Abhishek; Schlagel, D. L.; Lograsso, T. A.; Iowa State Univ., Ames, IA; Chakrabarti, Aparna; Barman, S. R.

    2015-08-20

    Momentum resolved inverse photoemission spectroscopy measurements show that the dispersion of the unoccupied bands of Ni2MnGa is significant in the austenite phase. Furthermore, in the martensite phase, it is markedly reduced, which is possibly related to the structural transition to an incommensurate modulated state in the martensite phase. Finally, based on the first principle calculations of the electronic structure of Ni–Mn–Ga, we show that the modification of the spectral shape with surface composition is related to change in the hybridization between the Mn 3d and Ni 3d-like states that dominate the unoccupied conduction band.

  2. Graphene in proximity to magnetic insulating LaMnO{sub 3}

    SciTech Connect (OSTI)

    Cheng, Guanghui; Wei, Laiming, E-mail: laiming@ustc.edu.cn, E-mail: cgzeng@ustc.edu.cn; Cheng, Long; Liang, Haixing; Zhang, Xiaoqiang; Li, Hui [Hefei National Laboratory for Physical Sciences at the Microscale (HFNL) and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yu, Guolin [Shanghai Institute of Technical Physics, Chinese Academy of Science, Shanghai 200083 (China); Zeng, Changgan, E-mail: laiming@ustc.edu.cn, E-mail: cgzeng@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale (HFNL) and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); International Center for Quantum Design of Functional Materials (ICQD), HFNL, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-09-29

    Proximity to functional substrates may enhance the coupling between the quantum degrees of freedom and thus develop nontrivial quantum effects in graphene. Here, we demonstrate the successful fabrication of graphene in proximity to atomically flat magnetic insulating LaMnO{sub 3} films. The insulating nature of the LaMnO{sub 3} films not only ensures the electronic transport only occur in the graphene layers but also allow them to serve as dielectric layers for gating. Transport measurements reveal anomalous behaviors, including asymmetrical longitudinal magnetoresistivity and nonlinear Hall effect. This work may pave a way toward the realization of intriguing quantum phases in graphene.

  3. Dy-Mn-Si as a representative of family of 'Dy-Transition

    Office of Scientific and Technical Information (OSTI)

    Metal-Si' systems: Its isothermal sections, empirical rProd. Type: FTPules and new rare-earth manganese silicides (Journal Article) | SciTech Connect Dy-Mn-Si as a representative of family of 'Dy-Transition Metal-Si' systems: Its isothermal sections, empirical rProd. Type: FTPules and new rare-earth manganese silicides Citation Details In-Document Search Title: Dy-Mn-Si as a representative of family of 'Dy-Transition Metal-Si' systems: Its isothermal sections, empirical rProd. Type: FTPules

  4. Magnetically nanostructured state in a Ni-Mn-Sn shape-memory alloy (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Magnetically nanostructured state in a Ni-Mn-Sn shape-memory alloy Citation Details In-Document Search This content will become publicly available on June 15, 2016 Title: Magnetically nanostructured state in a Ni-Mn-Sn shape-memory alloy Authors: Yuan, S. ; Kuhns, P. L. ; Reyes, A. P. ; Brooks, J. S. ; Hoch, M. J. R. ; Srivastava, V. ; James, R. D. ; El-Khatib, S. ; Leighton, C. Publication Date: 2015-06-16 OSTI Identifier: 1184888 Grant/Contract Number:

  5. Multiscale twin hierarchy in NiMnGa shape memory alloys with Fe and Cu

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Multiscale twin hierarchy in NiMnGa shape memory alloys with Fe and Cu Citation Details In-Document Search Title: Multiscale twin hierarchy in NiMnGa shape memory alloys with Fe and Cu Authors: Barabash, Rozaliya I. ; Barabash, Oleg M. ; Popov, Dmitry ; Shen, Guoyin ; Park, Changyong ; Yang, Wenge [1] ; ORNL) [2] ; CIW) [2] ; CHPSTAR- China) [2] + Show Author Affiliations (Tennessee-K) ( Publication Date: 2015-04-01 OSTI Identifier:

  6. Coexistence of charge-density wave and ferromagnetism in Ni2MnGa (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | DOE PAGES DOE PAGES Search Results Publisher's Accepted Manuscript: Coexistence of charge-density wave and ferromagnetism in Ni2MnGa « Prev Next » Title: Coexistence of charge-density wave and ferromagnetism in Ni2MnGa Authors: D'Souza, S. W. ; Rai, Abhishek ; Nayak, J. ; Maniraj, M. ; Dhaka, R. S. ; Barman, S. R. ; Schlagel, D. L. ; Lograsso, T. A. ; Chakrabarti, Aparna Publication Date: 2012-02-23 OSTI Identifier: 1099244 Type: Publisher's Accepted Manuscript Journal Name:

  7. Coexistence of charge-density wave and ferromagnetism in Ni2MnGa (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Coexistence of charge-density wave and ferromagnetism in Ni2MnGa Citation Details In-Document Search Title: Coexistence of charge-density wave and ferromagnetism in Ni2MnGa Authors: D'Souza, S. W. ; Rai, Abhishek ; Nayak, J. ; Maniraj, M. ; Dhaka, R. S. ; Barman, S. R. ; Schlagel, D. L. ; Lograsso, T. A. ; Chakrabarti, Aparna Publication Date: 2012-02-23 OSTI Identifier: 1099244 Type: Publisher's Accepted Manuscript Journal Name: Physical Review. B. Condensed

  8. Modeling and Characterization of the Magnetocaloric Effect in Ni2MnGa Materials

    SciTech Connect (OSTI)

    Nicholson, Don M; Odbadrakh, Khorgolkhuu; Shassere, Benjamin; Rios, Orlando; Hodges, Jason P; Ludtka, Gerard Michael; Porter, Wallace D; Safa-Sefat, Athena; Rusanu, Aurelian; Brown, Greg; Evans III, Boyd Mccutchen

    2014-01-01

    Magnetic shape memory alloys have great promise as magneto-caloric effect refrigerant materials due to their combined magnetic and structural transitions. Computational and experimental research is reported on the Ni2MnGa material system. The magnetic states of this system are explored using the Wang-Landau statistical approach in conjunction with the Locally Self-consistent Multiple-Scattering method. The effects of alloying agents on the transition temperatures of the Ni2MnGa alloy are investigated using differential scanning calorimetry and superconducting quantum interference device. Experiments are performed at the Spallation Neutron Source at Oak Ridge National Laboratory to observe the structural and magnetic phase transformations.

  9. Study of structural and electronic properties of Mn{sub 3}O{sub 4}

    SciTech Connect (OSTI)

    Kaur, Ramandeep Maitra, Tulika Nautiyal, Tashi

    2014-04-24

    Using density functional theory calculations we have examined the structural and electronic properties of magnetic spinel Mn{sub 3}O{sub 4}. We have optimized the structure (both volume and c/a ratio) within GGA. Then Coulomb correlations are included in the calculations to study the electronic properties. We observe that both the band gap and magnetic moment increase with the increase in Coulomb correlation due to the increased Jahn-Teller splitting and localization of the single e{sub g} electron of Mn{sup 3+}.

  10. Perpendicularly magnetized {tau}-MnAl (001) thin films epitaxied on GaAs

    SciTech Connect (OSTI)

    Nie, S. H.; Zhu, L. J.; Lu, J.; Pan, D.; Wang, H. L.; Yu, X. Z.; Xiao, J. X.; Zhao, J. H.

    2013-04-15

    Perpendicularly magnetized {tau}-MnAl films have been epitaxied on GaAs (001) by molecular-beam epitaxy. Crystalline quality and magnetic properties of the samples were strongly dependent on growth temperature. The highest coercivity of 10.7 kOe, saturation magnetization of 361.4 emu/cm{sup 3}, perpendicular magnetic anisotropy constant of 13.65 Merg/cm{sup 3}, and magnetic energy product of 4.44 MGOe were achieved. These tunable magnetic properties make MnAl films valuable as excellent and cost-effective alternative for not only high density perpendicular magnetic recording storage and spintronics devices but also permanent magnets.

  11. Magnetically nanostructured state in a Ni-Mn-Sn shape-memory alloy (Journal

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

    Article) | DOE PAGES Publisher's Accepted Manuscript: Magnetically nanostructured state in a Ni-Mn-Sn shape-memory alloy This content will become publicly available on June 15, 2016 Title: Magnetically nanostructured state in a Ni-Mn-Sn shape-memory alloy Authors: Yuan, S. ; Kuhns, P. L. ; Reyes, A. P. ; Brooks, J. S. ; Hoch, M. J. R. ; Srivastava, V. ; James, R. D. ; El-Khatib, S. ; Leighton, C. Publication Date: 2015-06-16 OSTI Identifier: 1184888 Grant/Contract Number: FG02-06ER46275

  12. X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation Complex

    Office of Scientific and Technical Information (OSTI)

    of Photosystem II (Journal Article) | SciTech Connect X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation Complex of Photosystem II Citation Details In-Document Search Title: X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation Complex of Photosystem II No abstract prepared. Authors: Sauer, K. ; Yano, J. ; Yachandra, V.K. ; /UC, Berkeley /LBL, Berkeley Publication Date: 2007-08-08 OSTI Identifier: 912555 Report Number(s): SLAC-REPRINT-2005-323 TRN: US200801%%922

  13. Enlarged Mn 3s splitting and room-temperature ferromagnetism in epitaxially grown oxygen doped Mn{sub 2}N{sub 0.86} films

    SciTech Connect (OSTI)

    Meng, M.; Wu, S. X. Ren, L. Z.; Zhou, W. Q.; Wang, Y. J.; Wang, G. L.; Li, S. W.

    2014-11-07

    Single-phase and oxygen doped Mn{sub 2}N{sub 0.86} thin films have been grown on MgO (111) by plasma-assisted molecular beam epitaxy. The films grow under tensile strain and, remarkably, they show ferromagnetic-like interactions at low temperature and ferromagnetic ordering agreed well with the Bloch-law T{sup 3/2} at room-temperature. We further demonstrate the enlarged Mn 3s splitting (6.46 eV) and its possible relation to the observed ferromagnetism. Our study not only provide a strategy for further theoretical work on oxygen doped manganese nitrides, but also shed promising light on utilizing its room-temperature FM property to fabricate spintronic devices.

  14. Characterization of few-layer 1T-MoSe{sub 2} and its superior performance in the visible-light induced hydrogen evolution reaction

    SciTech Connect (OSTI)

    Gupta, Uttam; Naidu, B. S.; Maitra, Urmimala; Rao, C. N. R.; Singh, Anjali; Shirodkar, Sharmila N.; Waghmare, Umesh V.

    2014-09-01

    Based on earlier results on the photocatalytic properties of MoS{sub 2}, the 1T form of MoSe{sub 2}, prepared by lithium intercalation and exfoliation of bulk MoSe{sub 2}, has been employed for the visible-light induced generation of hydrogen. 1T-MoSe{sub 2} is found to be superior to both 2H and 1T MoS{sub 2} as well as 2H-MoSe{sub 2} in producing hydrogen from water, the yield being in the 6075 mmol?h{sup ?1}?g{sup ?1} range with a turn over frequency of 1519 h{sup ?1}. First principles calculations reveal that 1T-MoSe{sub 2} has a lower work function than 2H-MoSe{sub 2} as well as 1T and 2H-MoS{sub 2}, making it easier to transfer an electron from 1T-MoSe{sub 2} for the production of H{sub 2}.

  15. Synthesis of MnO{sub 2}-graphene composites with enhanced supercapacitive performance via pulse electrodeposition under supergravity field

    SciTech Connect (OSTI)

    Liu, Tingting; Shao, Guangjie; Ji, Mingtong; Wang, Guiling

    2014-07-01

    A method of pulse electrodeposition under supergravity field was proposed to synthesize MnO{sub 2}-graphene composites. Supergravity is very efficient for promoting mass transfer and decreasing concentration polarization during the electrodeposition process. The synthesis was conducted on our homemade supergravity equipment. The strength of supergravity field depended on the rotating speed of the ring electrode. 3D flower like MnO{sub 2} spheres composed of nanoflakes were acquired when the rotating speed was 3000 rpm. Graphene nanosheets play as a role of conductive substrates for MnO{sub 2} growing. The composites are evaluated as electrode materials for supercapacitors. Electrochemical results show that the maximum specific capacitance of the MnO{sub 2}-graphene composite is 595.7 F g{sup ?1} at a current density of 0.5 A g{sup ?1}. In addition, the composite exhibits excellent cycle stability with no capacitance attenuation after 1000 cycles. The approach provides new ideas for developing supercapacitor electrode materials with high performance. - Graphical abstract: 3D flower like MnO{sub 2} spheres composed of nanoflakes were acquired at 3000 rpm. - Highlights: MnO{sub 2}-graphene composites were prepared by pulse electrodeposition under supergravity. 3D flower like MnO{sub 2} spheres are anchored on the graphene nanosheets. The MnO{sub 2}-graphene electrode exhibits a specific capacitance of 595.7 F g{sup ?1}.

  16. A practical grinding-assisted dry synthesis of nanocrystalline NiMoO{sub 4} polymorphs for oxidative dehydrogenation of propane

    SciTech Connect (OSTI)

    Chen Miao; Wu Jialing; Liu Yongmei; Cao Yong; Guo Li; He Heyong; Fan Kangnian

    2011-12-15

    A practical two-stage reactive grinding-assisted pathway waste-free and cost-effective for the synthesis of NiMoO{sub 4} has been successfully developed. It was demonstrated that proper design in synthetic strategy for grinding plays a crucial role in determining the ultimate polymorph of NiMoO{sub 4}. Specifically, direct grinding (DG) of MoO{sub 3} and NiO rendered {alpha}-NiMoO{sub 4} after annealing, whereas sequential grinding (SG) of the two independently pre-ground oxides followed by annealing generated {beta}-NiMoO{sub 4} solid solution. Characterizations in terms of Raman and X-ray diffraction suggest the creation of {beta}-NiMoO{sub 4} precursor in the latter alternative is the key aspect for the formation of {beta}-NiMoO{sub 4}. The DG-derived {alpha}-NiMoO{sub 4} tested by oxidative dehydrogenation of propane exhibited superior activity in contrast to its analog synthesized via conventional coprecipitation. It is suggested that the favorable chemical composition facilely obtained via grinding in contrast to that by coprecipitation was essential for achieving a more selective production of propylene. - Graphical Abstract: Grinding-assisted synthesis of NiMoO{sub 4} offers higher and more reproducible activities in contrast to coprecipitation for oxidative dehydrogenation of propane, and both {alpha}- and {beta}-NiMoO{sub 4} can be synthesized. Highlights: Black-Right-Pointing-Pointer NiMoO{sub 4} was prepared through grinding-assisted pathway. Black-Right-Pointing-Pointer Direct/sequential grinding rendered {alpha}-, {beta}-NiMoO{sub 4}, respectively. Black-Right-Pointing-Pointer Grinding-derived {alpha}-NiMoO{sub 4} showed high and reproducible activity for oxidative dehydrogenation of propane.

  17. Effect of Cu{sup 2+} and Ni{sup 2+} substitution at the Mn site in (La{sub

    Office of Scientific and Technical Information (OSTI)

    0.63}Ca{sub 0.37})MnO{sub 3}: A neutron powder diffraction investigation (Journal Article) | SciTech Connect Effect of Cu{sup 2+} and Ni{sup 2+} substitution at the Mn site in (La{sub 0.63}Ca{sub 0.37})MnO{sub 3}: A neutron powder diffraction investigation Citation Details In-Document Search Title: Effect of Cu{sup 2+} and Ni{sup 2+} substitution at the Mn site in (La{sub 0.63}Ca{sub 0.37})MnO{sub 3}: A neutron powder diffraction investigation The crystal and magnetic structures of the

  18. Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel using Atom Probe Tomography

    SciTech Connect (OSTI)

    Pereloma, E. V.; Stohr, R A; Miller, Michael K; Ringer, S. P.

    2009-01-01

    We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe){sub 3}Ti and (Ni,Fe){sub 3}(Al,Mn) precipitates eventually form after isothermal aging for {approx}60 seconds. The morphology of the (Ni,Fe){sub 3}Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe){sub 3}(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe){sub 3}Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation.

  19. Growth of single-crystal {alpha}-MnO{sub 2} nanorods on multi-walled carbon nanotubes

    SciTech Connect (OSTI)

    Chen Yong; Liu Chenguang; Liu Chang; Lu Gaoqing; Cheng Huiming

    2007-11-06

    Single-crystal {alpha}-MnO{sub 2} nanorods were grown on multi-walled carbon nanotubes (MWNTs) in H{sub 2}SO{sub 4} aqueous solution. The morphology and microstructure of the composites were examined by transmission electron microscopy, high-resolution transmission electron microscopy (HRTEM), X-ray diffractometry and energy dispersive spectroscopy (EDS). The results show that {alpha}-MnO{sub 2} single-crystal nanorods with a mean diameter of 15 nm were densely grown on the surface of MWNTs. Those MWNTs/MnO{sub 2} composites were used as an electrode material for supercapacitors, and it was found that the supercapacitor performance using MWNTs/MnO{sub 2} composites was improved largely compared to that using pure MWNTs and {alpha}-MnO{sub 2} nanorod mechanically mixed with MWNTs.

  20. Bulk and surface half-metallicity: The case of D0{sub 3}-type Mn{sub 3}Ge

    SciTech Connect (OSTI)

    Liu, Hao; Gao, G. Y. Hu, Lei; Ni, Yun; Zu, Fengxia; Zhu, Sicong; Wang, Shuling; Yao, K. L.

    2014-01-21

    Motivated by the experimental realization of D0{sub 22}-type Mn{sub 3}Ge (001) films [Kurt et al. Appl. Phys. Lett. 101, 132410 (2012)] and the structural stability of D0{sub 3}-type Heusler alloy Mn{sub 3}Ge [Zhang et al. J. Phys.: Condens. Matter 25, 206006 (2013)], we use the first-principles calculations based on the full potential linearized augmented plane-wave method to investigate the electronic and magnetic properties of D0{sub 3}-type Heusler alloy Mn{sub 3}Ge and its (001) surface. We show that bulk D0{sub 3}-Mn{sub 3}Ge is a half-metallic ferromagnet with the minority-spin energy gap of 0.52 eV and the magnetic moment of 1.00 μ{sub B} per formula unit. The bulk half-metallicity is preserved at the pure Mn-terminated (001) surface due to the large exchange split, but the MnGe-terminated (001) surface destroys the bulk half-metallicity. We also reveal that the surface stabilities are comparable between the D0{sub 3}-Mn{sub 3}Ge (001) and the experimental D0{sub 22}-Mn{sub 3}Ge (001), which indicates the feasibility to grow the Mn{sub 3}Ge (001) films with D0{sub 3} phase other than D0{sub 22} one. The surface half-metallicity and stability make D0{sub 3}-Mn{sub 3}Ge a promising candidate for spintronic applications.

  1. Print

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

    < 5k 0 < 50k < 100k < 250k < 500k < 1M > 1M > 5M > 10M DE MD DC MA RI NJ AZ UT WY ID OR WA CA TX OK KS CO NE SD ND MN WI IL IA MO AR LA MS AL FL GA TN KY IN OH MI ME NH CT VT NY PA WV VA NC SC MT AK HI NV NM Princeton Plasma Physics Laboratory Procured Materials and Services 2015 (> $35M) Small business procurements in US: $14.73M

  2. Annual Energy Outlook 2015 - Appendix B

    Gasoline and Diesel Fuel Update (EIA)

    5 U.S. Energy Information Administration | Annual Energy Outlook 2015 Regional maps Figure F4. Oil and gas supply model regions F-5 U.S. Energy Information Administration | Annual Energy Outlook 2014 Regional maps Figure F4. Oil and gas supply model regions Figure F4. Oil and Gas Supply Model Regions Atlantic WA MT WY ID NV UT CO AZ NM OK IA KS MO IL IN KY TN MS AL FL GA SC NC WV PA NJ MD DE NY CT ME RI MA NH VA WI MI OH NE SD MN ND AR OR CA VT East (1) Gulf of Mexico LA Gulf Coast (2)

  3. Annual Energy Outlook 2015 - Appendix F

    Gasoline and Diesel Fuel Update (EIA)

    7 U.S. Energy Information Administration | Annual Energy Outlook 2015 Regional maps Figure F6. Coal supply regions WA ID OR CA NV UT TX OK AR MO LA MS AL GA FL TN SC NC KY VA WV WY CO SD ND MI MN WI IL IN OH MD PA NJ DE CT MA NH VT NY ME RI MT NE IA KS MI AZ NM 500 0 SCALE IN MILES APPALACHIA Northern Appalachia Central Appalachia Southern Appalachia INTERIOR NORTHERN GREAT PLAINS Eastern Interior Western Interior Gulf Lignite Dakota Lignite Western Montana Wyoming, Northern Powder River Basin

  4. padd map

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

    FL PADD 4: Rocky Mountain PADD 5: West Coast PADD 2: Midwest PADD 1: East Coast PADD 3: Gulf Coast PADD1A: New England PADD1B: Central Atlantic PADD1C: Lower Atlantic Petroleum Administration for Defense Districts AK HI WA OR CA NV AZ MT WY CO UT ID ND SD NE KS OK MO MN WI MI IL IN OH KY TN IA NM TX AR LA AL MS WV VA NC SC GA FL ME NH VT NY PA NJ MD DE MA CT RI

  5. EIA-912.xls

    Gasoline and Diesel Fuel Update (EIA)

    Month 2 0 Address 2: City: State: Zip: - to meet the due date. Report volumes in million cubic feet (MMcf) @14.73 psia-60⁰ F.) No East Region (Million Cubic Feet) South Central Region (Million Cubic Feet) Midwest Region (Million Cubic Feet) Mountain Region (Million Cubic Feet) (AZ, CO, ID, MT, NE, ND, NM, NV, SD, UT, & WY) Midwest Region (Million Cubic Feet) (IL, IN, IA, KY, MI, MN, MO, TN, & WI) South Central Region (Million Cubic Feet) (AL, AR, KS, LA, MS, OK, & TX) Mountain

  6. Buildings Energy Data Book: 3.9 Educational Facilities

    Buildings Energy Data Book [EERE]

    6 2010 Regional New Construction and Renovations Expenditures for Public K-12 Schools ($Million) Region New Schools Additions Renovation Total Region 1 (CT, MA, ME, NH, RI, VT) Region 2 (NJ, NY, PA) Region 3 (DE, MD, VA, WV) Region 4 (KY, NC, SC, TN) Region 5 (AL, FL, GA, MS) Region 6 (IN, MI, OH) Region 7 (IL, MN, WI) Region 8 (IA, KS, MO, NE) Region 9 (AR, LA, OK, TX) Region 10 (CO, MT, ND, NM, SD, UT, WY) Region 11 (AZ, CA, HI, NV) Region 12 (AK, ID, OR, WA) Total Source(s): School Planning

  7. Modulation on Ni{sub 2}MnGa(001) surface

    SciTech Connect (OSTI)

    D'Souza, S. W.; Rai, Abhishek; Nayak, J.; Maniraj, M.; Dhaka, R. S.; Barman, S. R.; Schlagel, D. L.; Lograsso, T. A.

    2011-07-15

    We report periodic modulation on (001) surface of Ni2MnGa ferromagnetic shape memory alloy. For the stoichiometric surface, analysis of the low energy electron diffraction (LEED) spot profiles shows that the modulation is incommensurate. The modulation appears at 200 K, concomitant with the first order structural transition to the martensitic phase.

  8. Short- and long-range magnetic order in LaMnAsO

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

    McGuire, Michael A.; Garlea, Vasile Ovidiu

    2016-02-02

    The magnetic properties of the layered oxypnictide LaMnAsO have been revisited using neutron scattering and magnetization measurements. The present measurements identify the Néel temperature T N =360(1) K. Below T N the critical exponent describing the magnetic order parameter is β=0.33–0.35 , consistent with a three-dimensional Heisenberg model. Above this temperature, diffuse magnetic scattering indicative of short-range magnetic order is observed, and this scattering persists up to T SRO =650(10) K. Morevoer, the magnetic susceptibility shows a weak anomaly at T SRO and no anomaly at T N . Analysis of the diffuse scattering data using a reverse Monte Carlomore » algorithm indicates that above T N nearly two-dimensional, short-range magnetic order is present with a correlation length of 9.3(3) Å within the Mn layers at 400 K. The inelastic scattering data reveal a spin gap of 3.5 meV in the long-range ordered state, and strong, low-energy (quasielastic) magnetic excitations emerging in the short-range ordered state. When we compared it with other related compounds correlates the distortion of the Mn coordination tetrahedra to the sign of the magnetic exchange along the layer-stacking direction, and suggests that short-range order above T N is a common feature in the magnetic behavior of layered Mn-based pnictides and oxypnictides.« less

  9. Aliovalent titanium substitution in layered mixed Li Ni-Mn-Co oxides for lithium battery applications

    SciTech Connect (OSTI)

    Kam, Kinson; Doeff, Marca M.

    2010-12-01

    Improved electrochemical characteristics are observed for Li[Ni1/3Co1/3-yMyMn1/3]O2 cathode materials when M=Ti and y<0.07, compared to the baseline material, with up to 15percent increased discharge capacity.

  10. Ordering ferromagnetic In{sub 1?x}Mn{sub x}As quantum dots

    SciTech Connect (OSTI)

    Ferri, Fabio A.; Marega Jr, Euclydes; Kunets, Vasyl P.; Salamo, Gregory J.

    2013-12-04

    In this work, we present a method to order low temperature (LT) self-assembled ferromagnetic In{sub 1?x}Mn{sub x}As quantum dots (QDs) grown by molecular beam epitaxy (MBE). The ordered In{sub 1?x}Mn{sub x}As QDs were grown on top of a non-magnetic In{sub 0.4}Ga{sub 0.6}As/GaAs(100) QDs multi-layered structure. The modulation of the chemical potential, due to the stacking, provides a nucleation center for the LT In{sub 1?x}Mn{sub x}As QDs. For particular conditions, such as surface morphology and growth conditions, the In{sub 1?x}Mn{sub x}As QDs align along lines like chains. For comparison purposes, we also report the study of QDs grown on plain GaAs(100) substrates. Ferromagnetic behavior was observed for all structures at 2 K.

  11. Evaluation of Li2MnSiO4 Cathode | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    11 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation PDF icon es018_belharouak_2011_p.pdf More Documents & Publications Search for High Energy Density Cathode Materials Evaluation of Li2MnSiO4 Cathode Design of Safer High-Energy Density Materials for Lithium-Ion Cells

  12. Evaluation of Li2MnSiO4 Cathode | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    09 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. PDF icon esp_18_belharouak.pdf More Documents & Publications Search for High Energy Density Cathode Materials Evaluation of Li2MnSiO4 Cathode Vehicle Technologies Office Merit Review 2014: High-Capacity Polyanion Cathodes

  13. CaMn2Sb2: Spin waves on a frustrated antiferromagnetic honeycomb lattice

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

    McNally, D. E.; Simonson, J. W.; Kistner-Morris, J. J.; Smith, G. J.; Hassinger, J. E.; DeBeer-Schmidt, L.; Kolesnikov, A. I.; Zaliznyak, I.; Aronson, M. C.

    2015-05-22

    We present inelastic neutron scattering measurements of the antiferromagnetic insulator CaMn2Sb2:, which consists of corrugated honeycomb layers of Mn. The dispersion of magnetic excitations has been measured along the H and L directions in reciprocal space, with a maximum excitation energy of ≈ 24 meV. These excitations are well described by spin waves in a Heisenberg model, including first and second neighbor exchange interactions, J1 and J2, in the Mn plane and also an exchange interaction between planes. The determined ratio J2/J1 ≈ 1/6 suggests that CaMn2Sb2: is the first example of a compound that lies very close to themore »mean field tricritical point, known for the classical Heisenberg model on the honeycomb lattice, where the N´eel phase and two different spiral phases coexist. The magnitude of the determined exchange interactions reveal a mean field ordering temperature ≈ 4 times larger than the reported N´eel temperature TN = 85 K, suggesting significant frustration arising from proximity to the tricritical point.« less

  14. TYPE Ia SUPERNOVA REMNANT SHELL AT z = 3.5 SEEN IN THE THREE SIGHTLINES TOWARD THE GRAVITATIONALLY LENSED QSO B1422+231

    SciTech Connect (OSTI)

    Hamano, Satoshi; Kobayashi, Naoto [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Kondo, Sohei [Koyama Astronomical Observatory, Kyoto-Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555 (Japan); Tsujimoto, Takuji [National Astronomical Observatory of Japan and Department of Astronomical Science, Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Okoshi, Katsuya [Faculty of Industrial Science and Technology, Tokyo University of Science, 102-1 Tomino, Oshamanbe, Hokkaido 049-3514 (Japan); Shigeyama, Toshikazu, E-mail: hamano@ioa.s.u-tokyo.ac.jp [Research Center for the Early Universe, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)

    2012-08-01

    Using the Subaru 8.2 m Telescope with the IRCS Echelle spectrograph, we obtained high-resolution (R = 10,000) near-infrared (1.01-1.38 {mu}m) spectra of images A and B of the gravitationally lensed QSO B1422+231 (z = 3.628) consisting of four known lensed images. We detected Mg II absorption lines at z = 3.54, which show a large variance of column densities ({approx}0.3 dex) and velocities ({approx}10 km s{sup -1}) between sightlines A and B with a projected separation of only 8.4h{sup -1}{sub 70} pc at that redshift. This is the smallest spatial structure of the high-z gas clouds ever detected after Rauch et al. found a 20 pc scale structure for the same z = 3.54 absorption system using optical spectra of images A and C. The observed systematic variances imply that the system is an expanding shell as originally suggested by Rauch et al. By combining the data for three sightlines, we managed to constrain the radius and expansion velocity of the shell ({approx}50-100 pc, 130 km s{sup -1}), concluding that the shell is truly a supernova remnant (SNR) rather than other types of shell objects, such as a giant H II region. We also detected strong Fe II absorption lines for this system, but with much broader Doppler width than that of {alpha}-element lines. We suggest that this Fe II absorption line originates in a localized Fe II-rich gas cloud that is not completely mixed with plowed ambient interstellar gas clouds showing other {alpha}-element low-ion absorption lines. Along with the Fe richness, we conclude that the SNR is produced by an SN Ia explosion.

  15. Helical antiferromagnetic ordering in Lu1-xScxMnSi

    SciTech Connect (OSTI)

    Goetsch, Ryan J; Anand, V K; Johnston, David C

    2014-08-01

    Polycrystalline samples of Lu1?xScxMnSi (x=0, 0.25, 0.5) are studied using powder x-ray diffraction, heat capacity Cp, magnetization, magnetic susceptibility ?, and electrical resistivity ? measurements versus temperature T and magnetic field H. This system crystallizes in the primitive orthorhombic TiNiSi-type structure (space group Pnma) as previously reported. The ?(T) data indicate metallic behavior. The Cp(T), ?(T), and ?(T) measurements consistently indicate long-range antiferromagnetic (AF) transitions with AF ordering temperatures TN=246, 215, and 188 K for x=0, 0.25, and 0.5, respectively. A second transition is observed at somewhat lower T for each sample from the ?(T) and ?(T) measurements, which we speculate are due to spin reorientation transitions; these second transitions are completely suppressed in H=5.5 T. The Cp data below 10 K for each composition indicate an enhanced Sommerfeld electronic heat capacity coefficient for the series in the range ?=2429 mJ/mol K2. The ?(T) measurements up to 1000 K were fitted by local-moment Curie-Weiss behaviors which indicate a low Mn spin S?1. The ? data below TN are analyzed using the Weiss molecular field theory for a planar noncollinear cycloidal AF structure with a composition-dependent pitch, following the previous neutron diffraction work of Venturini et al. [J. Alloys Compd. 256, 65 (1997)]. Within this model, the fits indicate a turn angle between Mn ordered moments along the cycloid axis of ?100? or ?145?, either of which indicate dominant AF interactions between the Mn spins in the Lu1?xScxMnSi series of compounds.

  16. Martensitic transformation behaviors of rapidly solidified TiNiMo powders

    SciTech Connect (OSTI)

    Kim, Yeon-wook

    2012-10-15

    For the fabrication of bulk near-net-shape shape memory alloys and porous metallic biomaterials, consolidation of TiNiMo alloy powders is more useful than that of elemental powders of Ti, Ni and Mo. Ti{sub 50}Ni{sub 49.9}Mo{sub 0.1} shape memory alloy powders were prepared by gas atomization, and transformation temperatures and microstructures of those powders were investigated as a function of powder size. XRD analysis showed that the B2RB19 martensitic transformation occurred in powders smaller than 150 ?m. According to DSC analysis of the as-atomized powders, the B2R transformation temperature (T{sub R}) of the 2550 ?m powders was 18.4 C. The T{sub R} decreased with increasing powder size, however, the difference in T{sub R} between 2550 ?m powders and 100150 ?m powders is only 1 C. Evaluation of powder microstructures was based on SEM examination of the surface and the polished and etched powder cross sections and the typical images of the rapidly solidified powders showed cellular morphology. Porous cylindrical foams of 10 mm diameter and 1.5 mm length were fabricated by spark plasma sintering (SPS) at 800 C and 5 MPa. Finally these porous TiNi alloy samples are heat-treated for 1 h at 850 C, and then quenched in ice water. The bulk samples have 23% porosity and 4.6 g/cm{sup 3} density and their T{sub R} is 17.8 C.

  17. Extraordinary selectivity of CoMo{sub 3}S{sub 13} chalcogel for C{sub 2}H{sub 6} and CO{sub 2} adsorption.

    SciTech Connect (OSTI)

    Shafaei-Fallah, M.; Rothenberger, Z.; Katsoulidis, A. P.; He, J.; Malliakas, C. D.; Kanatzidis, M. G.

    2011-11-09

    The chalcogel CoMo{sub 3}S{sub 13} is obtained from the reaction of (NH{sub 4}){sub 2}[Mo{sub 3}S{sub 13}] with cobalt acetate in solution. The chalcogel has a BET surface area of 570 m{sup 2} g{sup -1}, and pair distribution function analysis (PDF) and infrared spectroscopy indicate that the [Mo{sub 3}S{sub 13}]{sup 2-} cluster is a building block in the porous network. The CoMo{sub 3}S{sub 13} chalcogel exhibits high selectivity for separating ethane and carbon dioxide from hydrogen and methane.

  18. In Situ Time-Resolved Characterization of Novel Cu-MoO2 Catalysts During the Water-Gas Shift Reaction

    SciTech Connect (OSTI)

    Wen ,W.; Liu, J.; White, M.; Marinkovic, N.; Hanson, J.; Rodriguez, J.

    2007-01-01

    A novel and active Cu-MoO{sub 2} catalyst was synthesized by partial reduction of a precursor CuMoO{sub 4} mixed-metal oxide with CO or H{sub 2} at 200-250 C. The phase transformations of Cu-MoO{sub 2} during H{sub 2} reduction and the water-gas shift reaction could be followed by In situ time resolved XRD techniques. During the reduction process the diffraction pattern of the CuMoO{sub 4} collapsed and the copper metal lines were observed on an amorphous material background that was assigned to molybdenum oxides. During the first pass of water-gas shift (WGS) reaction, diffraction lines for Cu{sub 6}Mo{sub 5}O{sub 18} and MoO{sub 2} appeared around 350 C and Cu{sub 6}Mo{sub 5}O{sub 18} was further transformed to Cu/MoO{sub 2} at higher temperature. During subsequent passes, significant WGS catalytic activity was observed with relatively stable plateaus in product formation around 350, 400 and 500 C. The interfacial interactions between Cu clusters and MoO{sub 2} increased the water-gas shift catalytic activities at 350 and 400 C.

  19. Microsoft Word - chapter FeNiCrMo_ver4.doc

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

    Low-Alloy Ferritic Steels: Tempered Fe-Ni-Cr-Mo Alloys (code 1212) Prepared by: B.P. Somerday, Sandia National Laboratories Editors C. San Marchi B.P. Somerday Sandia National Laboratories This report may be updated and revised periodically in response to the needs of the technical community; up-to-date versions can be requested from the editors at the address given below or downloaded at http://www.ca.sandia.gov/matlsTechRef/ . The success of this reference depends upon feedback from the

  20. Corrosion and degradation of a polyurethane/Co-Ni-Cr-Mo pacemaker lead

    SciTech Connect (OSTI)

    Sung, P.; Fraker, A.C.

    1987-12-01

    An investigation to study changes in the metal surfaces and the polyurethane insulation of heart pacemaker leads under controlled in vitro conditions was conducted. A polyurethane (Pellethane 2363-80A)/Co-Ni-Cr-Mo (MP35N) wire lead was exposed in Hanks' physiological saline solution for 14 months and then analyzed using scanning electron microscopy, x-ray energy dispersive analysis, and small angle x-ray scattering. Results showed that some leakage of solution into the lead had occurred and changes were present on both the metal and the polyurethane surfaces.

  1. Structural and magnetic properties of magnetron sputtered Ni-Mn-Sn ferromagnetic shape memory alloy thin films

    SciTech Connect (OSTI)

    Vishnoi, Ritu; Kaur, Davinder

    2010-05-15

    In the present study, structural and magnetic properties of Mn-rich, off-stoichiometric, nanocrystalline Ni-Mn-Sn ferromagnetic shape memory alloy thin films, grown on Si (100) substrates at 550 deg. C by dc magnetron sputtering have been systematically investigated. The crystallization, surface morphology, and structural features were studied using x-ray diffraction, atomic force microscopy, and field emission scanning electron microscopy. The structural transition from austenite to martensite was observed with an increase of Mn content. Austenitic phase with mixed L2{sub 1}/A2+B2 structure has been observed at room temperature in Ni{sub 52.6}Mn{sub 23.7}Sn{sub 23.6} (S{sub 1}) and Ni{sub 51.5}Mn{sub 26.1}Sn{sub 22.2} (S{sub 2}) films, while those with composition of Ni{sub 58.9}Mn{sub 28.0}Sn{sub 13.0} (S{sub 3}) and Ni{sub 58.3}Mn{sub 29.0}Sn{sub 12.6} (S{sub 4}) show martensitic phase with 14M modulated monoclinic structures. Field induced martensite-austenite transformation has been observed in magnetization studies using superconducting quantum interference device magnetometer. Temperature dependent magnetization measurements demonstrate the influence of magnetic field on the structural phase transition temperature. The investigations reveal an increase of martensitic transformation temperature (T{sub M}) with corresponding increase in substitution of Mn. The films exhibit ferromagnetic behavior at low temperatures below Curie temperature (T{sub C}). The decrease in saturation moment with increasing Mn content, indicates the existence of antiferromagnetic correlations within ferromagnetic matrix.

  2. Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for

    Office of Scientific and Technical Information (OSTI)

    Room-temperature Nuclear Radiation Detectors (Journal Article) | SciTech Connect Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for Room-temperature Nuclear Radiation Detectors Citation Details In-Document Search Title: Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for Room-temperature Nuclear Radiation Detectors Bridgman-grown cadmium zinc telluride (CdZnTe or CZT) and cadmium manganese telluride (CdMnTe or CMT) crystals often have Te inclusions that

  3. Atomic moments in Mn2CoAl thin films analyzed by X-ray magnetic circular dichroism

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

    Jamer, M. E.; Assaf, B. A.; Sterbinsky, G. E.; Arena, D. A.; Heiman, D.

    2014-12-05

    Spin gapless semiconductors are known to be strongly affected by structural disorder when grown epitaxially as thin films. The magnetic properties of Mn2CoAl thin films grown on GaAs (001) substrates are investigated here as a function of annealing. This study investigates the atomic-specific magnetic moments of Mn and Co atoms measured through X-ray magnetic circular dichroism as a function of annealing and the consequent structural ordering. Results indicate that the structural distortion mainly affects the Mn atoms as seen by the reduction of the magnetic moment from its predicted value.

  4. Atomic moments in Mn{sub 2}CoAl thin films analyzed by X-ray magnetic circular dichroism

    SciTech Connect (OSTI)

    Jamer, M. E.; Assaf, B. A.; Heiman, D.; Sterbinsky, G. E.; Arena, D. A.

    2014-12-07

    Spin gapless semiconductors are known to be strongly affected by structural disorder when grown epitaxially as thin films. The magnetic properties of Mn{sub 2}CoAl thin films grown on GaAs (001) substrates are investigated here as a function of annealing. This study investigates the atomic-specific magnetic moments of Mn and Co atoms measured through X-ray magnetic circular dichroism as a function of annealing and the consequent structural ordering. The results indicate that the structural distortion mainly affects the Mn atoms as seen by the reduction of the magnetic moment from its predicted value.

  5. Structural characterization of the FeTiO{sub 3}-MnTiO{sub 3} solid solution

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Structural characterization of the FeTiO{sub 3}-MnTiO{sub 3} solid solution Citation Details In-Document Search Title: Structural characterization of the FeTiO{sub 3}-MnTiO{sub 3} solid solution We have synthesized the (Mn{sub 1-x}Fe{sub x})TiO{sub 3} (0.0{<=}x{<=}1.0) solid solution compounds by high-temperature sintered methods, and characterized their crystal structures by combining X-ray diffraction, Moessbauer spectroscopy and Raman

  6. Spin and valley transport in monolayers of MoS{sub 2}

    SciTech Connect (OSTI)

    Sun, J. F.; Cheng, F.

    2014-04-07

    We investigate theoretically quantum transport and Goos-Hnchen (GH) effect of electrons in a p-n-p junction on monolayers of MoS{sub 2}. We find that the transmission properties of spin-up (spin-down) electrons in K valley are the same with spin-down (spin-up) electrons in K? valley due to the time-reversal symmetry. The GH shifts for the transmitted K and K? beams in the n-p interface are in the opposite direction, and GH shifts for the spin-up and spin-down electron beams at the same valley have different values in the same direction due to the different group velocities. Therefore, the spin-up and spin-down electrons can be separated after passing a sufficiently long channel created by a p-n-p junction. These features provide us a new way to generate a fully spin- and valley-polarized current in monolayers of MoS{sub 2}.

  7. On the bonding nature of electron states for the Fe-Mo double perovskite

    SciTech Connect (OSTI)

    Carvajal, E.; Cruz-Irisson, M.; Oviedo-Roa, R.; Navarro, O.

    2014-05-15

    The electronic transport as well as the effect of an external magnetic field has been investigated on manganese-based materials, spinels and perovskites. Potential applications of double perovskites go from magnetic sensors to electrodes in solid-oxide fuel cells; besides the practical interests, it is known that small changes in composition modify radically the physical properties of double perovskites. We have studied the Sr{sub 2}FeMoO{sub 6} double perovskite compound (SFMO) using first-principles density functional theory. The calculations were done within the generalized gradient approximation (GGA) scheme with the Perdew-Burke-Ernzerhof (PBE) functional. We have made a detailed analysis of each electronic state and the charge density maps around the Fermi level. For the electronic properties of SFMO it was used a primitive cell, for which we found the characteristic half-metallic behavior density of states composed by e{sub g} and t{sub 2g} electrons from Fe and Mo atoms. Those peaks were tagged as bonding or antibonding around the Fermi level at both, valence and conduction bands.

  8. Experimental study of the electric dipole strength in the even Mo nuclei and its deformation dependence

    SciTech Connect (OSTI)

    Erhard, M.; Junghans, A. R.; Nair, C.; Schwengner, R.; Beyer, R.; Klug, J.; Kosev, K.; Wagner, A.; Grosse, E.

    2010-03-15

    Two methods based on bremsstrahlung were applied to the stable even Mo isotopes for the experimental determination of the photon strength function covering the high excitation energy range above 4 MeV with its increasing level density. Photon scattering was used up to the neutron separation energies S{sub n} and data up to the maximum of the isovector giant resonance (GDR) were obtained by photoactivation. After a proper correction for multistep processes the observed quasicontinuous spectra of scattered photons show a remarkably good match to the photon strengths derived from nuclear photoeffect data obtained previously by neutron detection and corrected in absolute scale by using the new activation results. The combined data form an excellent basis to derive a shape dependence of the E1 strength in the even Mo isotopes with increasing deviation from the N=50 neutron shell (i.e., with the impact of quadrupole deformation and triaxiality). The wide energy coverage of the data allows for a stringent assessment of the dipole sum rule and a test of a novel parametrization developed previously which is based on it. This parametrization for the electric dipole strength function in nuclei with A>80 deviates significantly from prescriptions generally used previously. In astrophysical network calculations it may help to quantify the role the p-process plays in cosmic nucleosynthesis. It also has impact on the accurate analysis of neutron capture data of importance for future nuclear energy systems and waste transmutation.

  9. Electronic structure and conductivity of nanocomposite metal (Au,Ag,Cu,Mo)-containing amorphous carbon films

    SciTech Connect (OSTI)

    Endrino, Jose L.; Horwat, David; Gago, Raul; Andersson, Joakim; Liu, Y.S.; Guo, Jinghua; Anders, Andre

    2008-05-14

    In this work, we study the influence of the incorporation of different metals (Me = Au, Ag, Cu, Mo) on the electronic structure of amorphous carbon (a-C:Me) films. The films were produced at room temperature using a novel pulsed dual-cathode arc deposition technique. Compositional analysis was performed with secondary neutral mass spectroscopy whereas X-ray diffraction was used to identify the formation of metal nanoclusters in the carbon matrix. The metal content incorporated in the nanocomposite films induces a drastic increase in the conductivity, in parallel with a decrease in the band gap corrected from Urbach energy. The electronic structure as a function of the Me content has been monitored by x-ray absorption near edge structure (XANES) at the C K-edge. XANES showed that the C host matrix has a dominant graphitic character and that it is not affected significantly by the incorporation of metal impurities, except for the case of Mo, where the modifications in the lineshape spectra indicated the formation of a carbide phase. Subtle modifications of the spectral lineshape are discussed in terms of nanocomposite formation.

  10. Octonary resistance states in La0.7Sr0.3MnO3/BaTiO3/La0.7Sr0.3MnO3

    Office of Scientific and Technical Information (OSTI)

    multiferroic tunnel junctions (Journal Article) | SciTech Connect Journal Article: Octonary resistance states in La0.7Sr0.3MnO3/BaTiO3/La0.7Sr0.3MnO3 multiferroic tunnel junctions Citation Details In-Document Search This content will become publicly available on October 6, 2016 Title: Octonary resistance states in La0.7Sr0.3MnO3/BaTiO3/La0.7Sr0.3MnO3 multiferroic tunnel junctions General drawbacks of current electronic/spintronic devices are high power consumption and low density storage. A

  11. Penetration depth and absorption mechanisms of spin currents in Ir{sub 20}Mn{sub 80} and Fe{sub 50}Mn{sub 50} polycrystalline films by ferromagnetic resonance and spin pumping

    SciTech Connect (OSTI)

    Merodio, P.; Ghosh, A.; Lemonias, C.; Gautier, E.; Ebels, U.; Chshiev, M.; Béa, H. E-mail: helene.bea@cea.fr; Baltz, V. E-mail: helene.bea@cea.fr

    2014-01-20

    Spintronics relies on the spin dependent transport properties of ferromagnets (Fs). Although antiferromagnets (AFs) are used for their magnetic properties only, some fundamental F-spintronics phenomena like spin transfer torque, domain wall motion, and tunnel anisotropic magnetoresistance also occur with AFs, thus making AF-spintronics attractive. Here, room temperature critical depths and absorption mechanisms of spin currents in Ir{sub 20}Mn{sub 80} and Fe{sub 50}Mn{sub 50} are determined by F-resonance and spin pumping. In particular, we find room temperature critical depths originating from different absorption mechanisms: dephasing for Ir{sub 20}Mn{sub 80} and spin flipping for Fe{sub 50}Mn{sub 50}.

  12. MoO3 as combined hole injection layer and tapered spacer in combinatorial multicolor microcavity organic light emitting diodes

    SciTech Connect (OSTI)

    Liu, R.; Xu, Chun; Biswas, Rana; Shinar, Joseph; Shinar, Ruth

    2011-09-01

    Multicolor microcavity ({mu}C) organic light-emitting diode (OLED) arrays were fabricated simply by controlling the hole injection and spacer MoO{sub 3} layer thickness. The normal emission was tunable from {approx}490 to 640 nm and can be further expanded. A compact, integrated spectrometer with two-dimensional combinatorial arrays of {mu}C OLEDs was realized. The MoO{sub 3} yields more efficient and stable devices, revealing a new breakdown mechanism. The pixel current density reaches {approx}4 A/cm{sup 2} and a maximal normal brightness {approx}140 000 Cd/m{sup 2}, which improves photoluminescence-based sensing and absorption measurements.

  13. Comparison of Two Preparation Methods on Catalytic Activity and Selectivity of Ru-Mo/HZSM5 for Methane Dehydroaromatization

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

    Petkovic, Lucia M.; Ginosar, Daniel M.

    2014-01-01

    Catalytic performance of Mo/HZSM5 and Ru-Mo/HZSM5 catalysts prepared by vaporization-deposition of molybdenum trioxide and impregnation with ammonium heptamolybdate was analyzed in terms of catalyst activity and selectivity, nitrogen physisorption analyses, temperature-programmed oxidation of carbonaceous residues, and temperature-programmed reduction. Vaporization-deposition rendered the catalyst more selective to ethylene and coke than the catalyst prepared by impregnation. This result was assigned to lower interaction of molybdenum carbide with the zeolite acidic sites.

  14. Enhancing the photocurrent and photoluminescence of single crystal monolayer MoS{sub 2} with resonant plasmonic nanoshells

    SciTech Connect (OSTI)

    Sobhani, Ali [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Lauchner, Adam [Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States); Najmaei, Sina; Lou, Jun [Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Ayala-Orozco, Ciceron; Wen, Fangfang [Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Halas, Naomi J., E-mail: halas@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

    2014-01-20

    Monolayer molybdenum disulfide (MoS{sub 2}) produced by controlled vapor-phase synthesis is a commercially promising new two-dimensional material for optoelectronics because of its direct bandgap and broad absorption in the visible and ultraviolet regimes. By tuning plasmonic core-shell nanoparticles to the direct bandgap of monolayer MoS{sub 2} and depositing them sparsely (<1% coverage) onto the material's surface, we observe a threefold increase in photocurrent and a doubling of photoluminescence signal for both excitonic transitions, amplifying but not altering the intrinsic spectral response.

  15. "Report Date","U.S.",,,"PADD I",,,"PADD IA",,,"PADD IB",,,"PADD IC",,,"PADD II"

    U.S. Energy Information Administration (EIA) Indexed Site

    Residential Heating Oil Prices (Before and After Change in Aggregation Methodology)" "Report Date","U.S.",,,"PADD I",,,"PADD IA",,,"PADD IB",,,"PADD IC",,,"PADD II" ,"Old Reported Value ($ per Gallon)","New Revised Value ($ per Gallon)","Difference","Old Reported Value ($ per Gallon)","New Revised Value ($ per Gallon)","Difference","Old Reported Value ($ per

  16. Anti-site disorder and improved functionality of Mn?NiX (X = Al, Ga, In, Sn) inverse Heusler alloys

    SciTech Connect (OSTI)

    Paul, Souvik; Kundu, Ashis; Ghosh, Subhradip; Sanyal, Biplab

    2014-10-07

    Recent first-principles calculations have predicted Mn?NiX (X = Al, Ga, In, Sn) alloys to be magnetic shape memory alloys. Moreover, experiments on Mn?NiGa and Mn?NiSn suggest that the alloys deviate from the perfect inverse Heusler arrangement and that there is chemical disorder at the sublattices with tetrahedral symmetry. In this work, we investigate the effects of such chemical disorder on phase stabilities and magnetic properties using first-principles electronic structure methods. We find that except Mn?NiAl, all other alloys show signatures of martensitic transformations in presence of anti-site disorder at the sublattices with tetrahedral symmetry. This improves the possibilities of realizing martensitic transformations at relatively low fields and the possibilities of obtaining significantly large inverse magneto-caloric effects, in comparison to perfect inverse Heusler arrangement of atoms. We analyze the origin of such improvements in functional properties by investigating electronic structures and magnetic exchange interactions.

  17. Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals...

    Office of Scientific and Technical Information (OSTI)

    Title: Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for Room-temperature Nuclear Radiation Detectors Bridgman-grown cadmium zinc telluride (CdZnTe or CZT) and ...

  18. Thermoelectric properties of nano-meso-micro β-MnO₂ powders as a function of electrical resistance

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

    Hedden, Morgan; Francis, Nick; Haraldsen, Jason T.; Ahmed, Towfiq; Constantin, Costel

    2015-07-15

    Particle sizes of manganese oxide (β-MnO₂) powders were modified by using a mortar and pestle ground method for period of times that varied between 15–60 min. Particle size versus ground time clearly shows the existence of a size-induced regime transition (i.e., regime I and II). Thermoelectric properties of β-MnO₂ powders as a function of electrical resistance in the range of RP = 10 - 80Ω were measured. Based on the data presented, we propose a model for the β-MnO₂ system in which nanometer-scale MnO₂ crystallites bond together through weak van der Waals forces to form larger conglomerates that span inmore » size from nanometer to micrometer scale.« less

  19. Laser activation of ferromagnetism in hydrogenated Ga{sub 1-x}Mn{sub x}As

    SciTech Connect (OSTI)

    Farshchi, R.; Dubon, O. D.; Hwang, D. J.; Misra, N.; Grigoropoulos, C. P.; Ashby, P. D.

    2008-01-07

    We demonstrate the local depassivation of hydrogenated Ga{sub 1-x}Mn{sub x}As by pulsed-laser annealing. The controlled removal of Mn-H defect complexes, which form upon hydrogenation and render Mn acceptors inactive, is achieved by focused laser irradiation. As a result, regions of electrically and ferromagnetically active Ga{sub 1-x}Mn{sub x}As are formed within a nonactive, otherwise structurally identical film. The hydrogenated films subjected to blanket laser depassivation display a Curie temperature T{sub C} up to 60 K, or 60% of the T{sub C} of the as-grown films. These results demonstrate the direct laser writing of mesoscopic ferromagnetically active regions as a viable route for the realization of planar, nanoscale spintronic systems.

  20. Structural, elastic, electronic, magnetic and vibrational properties of CuCoMnGa under pressure

    SciTech Connect (OSTI)

    ?yigr, Ahmet; U?ur, ?ule

    2014-10-06

    First principles calculations for the structural, electronic, elastic and phonon properties of the cubic quaternary heusler alloy CuCoMnGa on pressure have been reported by density functional theory (DFT) within generalized gradient approximation (GGA). The calculated values of the elastic constants were used for estimations of the Debye temperatures, the bulk modulus, the shear modulus, the young modulus E, the poisson's ratio ? and the B/G ratio. The elastic constants satisfy all of the mechanical stability criteria. The electronic structures of the ferromagnetic configuration for CuCoMnGa have a metallic character. The estimated magnetic moment per formula unit is 3.76 ?{sub B}. The phonon dispersion is studied using the supercell approach, and the stable nature at 0.2 GPa pressure is observed.

  1. What is the valence of Mn in Ga1-xMnxN?

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

    Berlijn, Tom; Jarrell, Mark; Nelson, Ryky; Ku, Wei; Moreno, Juana

    2015-11-04

    Motivated by the potential high Curie temperature of Ga1-xMnxN, we investigate the controversial Mn valence in this diluted magnetic semiconductor. From a first-principles Wannier-function analysis of the high energy Hilbert space, we find unambiguously the Mn valence to be close to 2+(d5), but in a mixed spin configuration with average magnetic moments of 4µB. By integrating out high-energy degrees of freedom differently, we further demonstrate the feasibility of both effective d4 and d5 descriptions. These two descriptions offer simple pictures for local and extended properties of the system, and highlight the dual nature of its doped hole. Specifically, in themore » effective d5 description, we demonstrate novel physical effects absent in previous studies. Thus, our derivation highlights the richness of low-energy sectors in interacting many-body systems and the generic need for multiple effective descriptions.« less

  2. Magneto-optical spectroscopy of ferromagnetic shape-memory Ni-Mn-Ga alloy

    SciTech Connect (OSTI)

    Veis, M. Beran, L.; Zahradnik, M.; Antos, R.; Straka, L.; Kopecek, J.; Fekete, L.; Heczko, O.

    2014-05-07

    Magneto-optical properties of single crystal of Ni{sub 50.1}Mn{sub 28.4}Ga{sub 21.5} magnetic shape memory alloy in martensite and austenite phase were systematically studied. Crystal orientation was approximately along (100) planes of parent cubic austenite. At room temperature, the sample was in modulated 10M martensite phase and transformed to cubic austenite at 323?K. Spectral dependence of polar magneto-optical Kerr effect was obtained by generalized magneto-optical ellipsometry with rotating analyzer in the photon energy range from 1.2 to 4?eV, and from room temperature to temperature above the Curie point. The Kerr rotation spectra exhibit prominent features typical for complexes containing Mn atoms. Significant spectral changes during transformation to austenite can be explained by different optical properties caused by changes in density of states near the Fermi energy.

  3. Extrinsic anomalous Hall effect in epitaxial Mn{sub 4}N films

    SciTech Connect (OSTI)

    Meng, M.; Wu, S. X. Ren, L. Z.; Zhou, W. Q.; Wang, Y. J.; Wang, G. L.; Li, S. W.

    2015-01-19

    Anomalous Hall effect (AHE) in ferrimagnetic Mn{sub 4}N epitaxial films grown by molecular-beam epitaxy is investigated. The longitudinal conductivity σ{sub xx} is within the superclean regime, indicating Mn{sub 4}N is a highly conducting material. We further demonstrate that the AHE signal in 40-nm-thick films is mainly due to the extrinsic contributions based on the analysis fitted by ρ{sub AH}=a′ρ{sub xx0}+bρ{sub xx}{sup 2} and σ{sub AH}∝σ{sub xx}. Our study not only provide a strategy for further theoretical work on antiperovskite manganese nitrides but also shed promising light on utilizing their extrinsic AHE to fabricate spintronic devices.

  4. Magnetochromic effect in multiferroic R In 1 ₋ x Mn x O 3 ( R = Tb , Dy)

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

    Chen, P.; Holinsworth, B. S.; O'Neal, K. R.; Brinzari, T. V.; Mazumdar, D.; Topping, C. V.; Luo, X.; Cheong, S.-W.; Singleton, J.; McGill, S.; et al

    2015-05-26

    We combined high field magnetization and magneto-optical spectroscopy to investigate spin-charge coupling in Mn-substituted rare-earth indium oxides of chemical formula RIn₁₋xMnxO₃ (R=Tb, Dy). The edge states, on-site Mn³⁺d to d excitations, and rare-earth f-manifold excitations all track the magnetization energy due to dominant Zeeman interactions. The field-induced modifications to the rare-earth excitations are quite large because spin-orbit coupling naturally mixes spin and charge, suggesting that the next logical step in the design strategy should be to bring spin-orbit coupling onto the trigonal bipyramidal chromophore site with a 4 or 5d center.

  5. Low temperature magnetic properties of magnesium substituted YbMnO{sub 3}

    SciTech Connect (OSTI)

    Sattibabu, Bhumireddi Bhatnagar, Anil K. Mohan, Dasari Das, Dibakar Sundararaman, Mahadevan; Siruguri, Vasudeva; Rayaprol, Sudhindra

    2014-04-24

    Structural and magnetic properties of polycrystalline Yb{sub 1?x}Mg{sub x}MnO{sub 3} (x = 0, 0.05 and 0.10) hexagonal compounds prepared by solid state method, have been studied. The structural analyses of the samples were carried out by Rietveld analysis of neutron diffraction data. With increasing Mg content, we find that the lattice parameter a decreases and c increases whereas the overall Mn-O bond length decreases. Magnetization measured as a function of magnetic field at 2.5 K exhibits hysteresis, which is attributed to ferromagnetic like ordering of Yb{sup 3+} sublattice. Temperature dependence of ac magnetic susceptibility, ?{sub ac}(T), shows no signature of spin-glass behavior. ?(T) exhibits a sudden increase at low temperatures which is due to ordering of Yb{sup 3+} sublattice.

  6. Homogeneity testing and quantitative analysis of manganese (Mn) in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS)

    SciTech Connect (OSTI)

    Unnikrishnan, V. K.; Nayak, Rajesh; Kartha, V. B.; Santhosh, C. E-mail: unnikrishnan.vk@manipal.edu; Sonavane, M. S.; Yeotikar, R. G.; Shah, M. L.; Gupta, G. P.; Suri, B. M.

    2014-09-15

    Laser-induced breakdown spectroscopy (LIBS), an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn) in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.710{sup 9} W/cm{sup 2}. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX) surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.

  7. Magnetic fields and fluctuations in weakly Mn doped ZnGeP{sub 2}

    SciTech Connect (OSTI)

    Mengyan, P. W.; Lichti, R. L.; Baker, B. B.; Celebi, Y. G.; Catak, E.; Carroll, B. R.; Zawilski, K. T.; Schunemann, P. G.

    2014-02-21

    We report on our measurements of local and bulk magnetic features in weakly Mn doped ZnGeP{sub 2}. Utilizing muon spin rotation and relaxation measurements, we identify local ferromagnetic order and fluctuations in the local fields as sampled by an implanted muon (?{sup +}). We also report on field induced ferromagnetism occurring above the claimed paramagnetic to ferromagnetic transition temperature (T{sub c} = 312 K)

  8. MN Lup: X-RAYS FROM A WEAKLY ACCRETING T TAURI STAR

    SciTech Connect (OSTI)

    Guenther, H. M.; Wolk, S. J.; Wolter, U.; Robrade, J.

    2013-07-01

    Young T Tauri stars (TTS) are surrounded by an accretion disk, which over time disperses due to photoevaporation, accretion, and possibly planet formation. The accretion shock on the central star produces an UV/optical veiling continuum, line emission, and X-ray signatures. As the accretion rate decreases, the impact on the central star must change. In this article we study MN Lup, a young star where no indications of a disk are seen in IR observations. We present XMM-Newton and VLT/UVES observations, some of them taken simultaneously. The X-ray data show that MN Lup is an active star with L{sub X} /L{sub bol} close to the saturation limit. However, we find high densities (n{sub e} > 3 Multiplication-Sign 10{sup 10} cm{sup -3}) in the X-ray grating spectrum. This can be well fitted using an accretion shock model with an accretion rate of 2 Multiplication-Sign 10{sup -11} M{sub Sun} yr{sup -1}. Despite the simple H{alpha} line profile which has a broad component, but no absorption signatures as typically seen on accreting TTS, we find rotational modulation in Ca II K and in photospheric absorption lines. These line profile modulations do not clearly indicate the presence of a localized hot accretion spot on the star. In the H{alpha} line we see a prominence in absorption about 2R{sub *} above the stellar surface-the first of its kind on a TTS. MN Lup is also the only TTS where accretion is seen, but no dust disk is detected that could fuel it. We suggest that MN Lup presents a unique and short-lived state in the disk evolution. It may have lost its dust disk only recently and is now accreting the remaining gas at a very low rate.

  9. Inverse Design of Mn-based ternary p-type wide-gap oxides

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

    used theory to predict band structure and transport properties for the d 5 transition metal (TM) oxides MnO and Fe 2 O 3 . Significance and Impact This work identified design principles for improving d 5 oxides as a new class of semiconductors with potential applications in energy conversion. Design Principles Demonstrated for Semiconducting d 5 Transition-Metal Oxides with Photovoltaic Applications Potential H. Peng and S. Lany, Phys. Rev. B (Rapid Comm.) 85, 201202(R) (2012). Figure 1:

  10. Thermoelectric study of crossroads material MnTe via sulfur doping

    SciTech Connect (OSTI)

    Xie, Wenjie Populoh, Sascha; Sagarna, Leyre; Trottmann, Matthias; Ga??zka, Krzysztof; Xiao, Xingxing; Liu, Yufei; He, Jian; Weidenkaff, Anke

    2014-03-14

    Here, we report thermoelectric study of crossroads material MnTe via iso-electronic doping S on the Te-site. MnTe{sub 1-x}S{sub x} samples with nominal S content of x?=?0.00, 0.05, and 0.10 were prepared using a melt-quench method followed by pulverization and spark plasma sintering. The X-ray powder diffraction, scanning electron microscopy, and ZAF-corrected compositional analysis confirmed that S uniformly substitutes Te up to slightly over 2%. A higher content of S in the starting materials led to the formation of secondary phases. The thermoelectric properties of MnTe{sub 1-x}S{sub x} samples were characterized by means of Seebeck coefficient, electrical conductivity, and thermal conductivity measurements from 300?K to 773?K. Furthermore, Hall coefficient measurements and a single parabolic band model were used to help gain insights on the effects of S-doping on the scattering mechanism and the carrier effective mass. As expected, S doping not only introduced hole charge carriers but also created short-range defects that effectively scatter heat-carrying phonons at elevated temperatures. On the other hand, we found that S doping degraded the effective mass. As a result, the ZT of MnTe{sub 0.9}S{sub 0.1} was substantially enhanced over the pristine sample near 400?K, while the improvement of ZT became marginal at elevated temperatures. A ZT???0.65 at 773?K was obtained in all three samples.

  11. Preparation and structural study from neutron diffraction data of Pr{sub 5}Mo{sub 3}O{sub 16}

    SciTech Connect (OSTI)

    Martinez-Lope, M.J.; Alonso, J.A.; Sheptyakov, D.; Pomjakushin, V.

    2010-12-15

    The title compound has been prepared as polycrystalline powder by thermal treatments of mixtures of Pr{sub 6}O{sub 11} and MoO{sub 2} in air. In the literature, an oxide with a composition Pr{sub 2}MoO{sub 6} has been formerly described to present interesting catalytic properties, but its true stoichiometry and crystal structure are reported here for the first time. It is cubic, isostructural with CdTm{sub 4}Mo{sub 3}O{sub 16} (space group Pn-3n, Z=8), with a=11.0897(1) A. The structure contains MoO{sub 4} tetrahedral units, with Mo-O distances of 1.788(2) A, fully long-range ordered with PrO{sub 8} polyhedra; in fact it can be considered as a superstructure of fluorite (M{sub 8}O{sub 16}), containing 32 MO{sub 2} fluorite formulae per unit cell, with a lattice parameter related to that of cubic fluorite (a{sub f}=5.5 A) as a{approx}2a{sub f}. A bond valence study indicates that Mo exhibits a mixed oxidation state between 5+ and 6+ (perhaps accounting for the excellent catalytic properties). One kind of Pr atoms is trivalent whereas the second presents a mixed Pr{sup 3+}-Pr{sup 4+} oxidation state. The similarity of the XRD pattern with that published for Ce{sub 2}MoO{sub 6} suggests that this compound also belongs to the same structural type, with an actual stoichiometry Ce{sub 5}Mo{sub 3}O{sub 16}. -- Graphical Abstract: Formerly formulated as Pr{sub 2}MoO{sub 6}, the title compound is a cubic superstructure of fluorite (a=11.0897(1) A, space group Pn-3n) due to the long-range ordering of PrO{sub 8} scalenohedra and MoO{sub 4} tetrahedral units, showing noticeable shifts of the oxygen positions in order to provide a tetrahedral coordination for Mo ions. A mixed valence Mo{sup 5+}-Mo{sup 6+} is identified, which could account for the excellent catalytic properties of this material. Display Omitted

  12. Toward epitaxially grown two-dimensional crystal hetero-structures: Single and double MoS{sub 2}/graphene hetero-structures by chemical vapor depositions

    SciTech Connect (OSTI)

    Lin, Meng-Yu [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Chang, Chung-En [Department of Photonics, National Chiao-Tung University, Hsinchu, Taiwan (China); Wang, Cheng-Hung [Institute of Display, National Chiao-Tung University, Hsinchu, Taiwan (China); Su, Chen-Fung; Chen, Chi [Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Lee, Si-Chen [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan (China); Lin, Shih-Yen, E-mail: shihyen@gate.sinica.edu.tw [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Department of Photonics, National Chiao-Tung University, Hsinchu, Taiwan (China)

    2014-08-18

    Uniform large-size MoS{sub 2}/graphene hetero-structures fabricated directly on sapphire substrates are demonstrated with layer-number controllability by chemical vapor deposition (CVD). The cross-sectional high-resolution transmission electron microscopy (HRTEM) images provide the direct evidences of layer numbers of MoS{sub 2}/graphene hetero-structures. Photo-excited electron induced Fermi level shift of the graphene channel are observed on the single MoS{sub 2}/graphene hetero-structure transistors. Furthermore, double hetero-structures of graphene/MoS{sub 2}/graphene are achieved by CVD fabrication of graphene layers on top of the MoS{sub 2}, as confirmed by the cross-sectional HRTEM. These results have paved the possibility of epitaxially grown multi-hetero-structures for practical applications.

  13. Redox Active Layer-by-Layer Structures containing MnO2 Nanoparticles

    SciTech Connect (OSTI)

    Bazito, Fernanda; O'Brien, Robert; Buttry, Daniel A.

    2005-02-01

    Nanoscale materials provide unique properties that will enable new technologies and enhance older ones. One area of intense activity in which nanoscale materials are being used is in the development of new functional materials for battery applications. This effort promises superior materials with properties that circumvent many of the problems associated with traditional battery materials. Previously we have worked on several approaches for using nanoscale materials for application as cathode materials in rechargeable Li batteries. Our recent work has focused on synthesizing MnO2 nanoparticles and using these in layer-by-layer (LbL) structures to probe the redox properties of the nanoparticles. We show that the aqueous colloidal nanoparticles produced by butanol reduction of tetramethylammonium permanganate can be trapped in thin films using a layer-by-layer deposition approach, and that these films are both redox active and exhibit kinetically facile electrochemical responses. We show cyclic voltammetry of MnO2 colloidal nanoparticles entrapped in a LbL thin film at an ITO electrode surface using poly(diallyldimethylammonium chloride) (PDDA). CV experiments demonstrate that Li+ insertion accompanies Mn(IV) reduction in LiClO4 supporting electrolytes, and that reduction is hindered in supporting electrolytes containing only tetrabutylammonium cations. We also show that electron propagation through multilayer films is facile, suggesting that electrons percolate through the films via electron exchange between nanoparticles.

  14. Correlating Local Structure with Electrochemical Activity in Li2MnO3

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

    Nanda, Jagjit; Sacci, Robert L.; Veith, Gabriel M.; Dixit, Hemant M.; Cooper, Valentino R.; Pezeshki, Alan M.; Ruther, Rose E.

    2015-07-31

    Li2MnO3 is of interest as one component of the composite lithium-rich oxides, which are under development for high capacity, high voltage cathodes in lithium ion batteries. Despite such practical importance, the mechanism of electrochemical activity in Li2MnO3 is contested in the literature, as are the effects of long-term electrochemical cycling. Here, Raman spectroscopy and mapping are used to follow the chemical and structural changes that occur in Li2MnO3. Both conventional slurry electrodes and thin films are studied as a function of the state of charge (voltage) and cycle number. Thin films have similar electrochemical properties as electrodes prepared from slurries,more » but allow for spectroscopic investigations on uniform samples without carbon additives. Spectral changes correlate well with electrochemical activity and support a mechanism whereby capacity is lost upon extended cycling due to the formation of new manganese oxide phases. Raman mapping of both thin film and slurry electrodes charged to different voltages reveals significant variation in the local structure. Poor conductivity and slow kinetics associated with a two-phase reaction mechanism contribute to the heterogeneity.« less

  15. Magnetization-steps in Y?CoMnO? double perovskite: The role of antisite disorder

    SciTech Connect (OSTI)

    Nair, Harikrishnan S. Xiao, Yinguo; Brckel, Th.; Cherian, Dona; Elizabeth, Suja; Hansen, Thomas; Chatterji, Tapan

    2014-09-28

    Antisite disorder is observed to have significant impact on the magnetic properties of the double perovskite YCoMnO? which has been recently identified as a multiferroic. A paramagnetic-ferromagnetic phase transition occurs in this material at Tc ? 75 K. At 2 K, it displays a strong ferromagnetic hysteresis with a significant coercive field of Hc ? 15 kOe. Sharp steps are observed in the hysteresis curves recorded below 8 K. In the temperature range 2 K ? T ? 5 K, the hysteresis loops are anomalous as the virgin curve lies outside the main loop. The field-cooling conditions as well as the rate of field-sweep are found to influence the steps. Quantitative analysis of the neutron diffraction data shows that at room temperature, Y?CoMnO? consists of 62% of monoclinic P2?/n with nearly 70% antisite disorder and 38% Pnma. The bond valence sums indicate the presence of other valence states for Co and Mn which arise from disorder. We explain the origin of steps by using a model for pinning of magnetization at the antiphase boundaries created by antisite disorder. The steps in magnetization closely resemble the martensitic transformations found in intermetallics and display first-order characteristics as revealed in the Arrott's plots.

  16. Spin-phonon study of EuMn{sub 2}O{sub 5} nanorods

    SciTech Connect (OSTI)

    Hsu, Ting-Wei; Yang, Chung-Cheun Tong, Yong-Xiang; Shih, Wei-Jhe; Lin, Kuen-Song

    2015-05-07

    EuMn{sub 2}O{sub 5} multiferroic nanorods, with diameters radial (?L{sub C}?) lengths of 25(6) nm 47(15) nm and 51(16) nm 70(26) nm, were fabricated by the hydrothermal method. Ferrimagnetic ordering below 50?K (T*) is observed in the ?L{sub C}??=?70?nm sample, which exhibited ferromagnetic (FM) behavior below T* in a field cooling process. No similar behavior was found in the ?L{sub C}??=?47?nm sample. These observations reveal that only the ?L{sub C}??=?70?nm sample has a meta-FM state, and this sample exhibits the stronger coupling between the Mn ions. Raman spectra of both sets of samples were obtained in 0, 610, 1000, 1600, and 2000?G magnetic fields. The red-shift of the A{sub g} (681?cm{sup ?1}) mode of the both samples increased with the strength of the field above 1000?G, indicating the existence of spin-phonon interaction. The smaller sampled exhibited a larger red-shift, suggesting that the size importantly affects the of EuMn{sub 2}O{sub 5} nanorods.

  17. MnO{sub 2}@colloid carbon spheres nanocomposites with tunable interior architecture for supercapacitors

    SciTech Connect (OSTI)

    Zhang, Yuxin; Liu, Chuanpu; Wen, Zhongquan

    2014-01-01

    Graphical abstract: - Highlights: MnO{sub 2}@CSs nanocomposites have been successfully synthesized in room temperature. The composites exhibited three structures: coreshell, yolkshell and hollow structure. The yolkshell structure exhibited a high specific capacitance and cycling stability. - Abstract: MnO{sub 2}@colloid carbon spheres nanocomposites with tunable interior architecture have been synthesized by a facile and cost-effective strategy at room temperature. The structure and morphology of as-prepared nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption, focused ion beam scanning electron microscopy (FIB/SEM) and high-resolution transmission electron microscopy (HRTEM). The as-obtained composites exhibited a three-dimensional architecture with coreshell, yolkshell and hollow interior structure. Furthermore, the electrochemical properties of composites were evaluated by cycle voltammetric (CV) and galvanostatic chargedischarge measurements. The yolkshell structure exhibited the optimized pseudocapacitance performance, revealing a specific capacitance (273 F g{sup ?1}) with a good rate and cycling stability, owing to its unique structure and the poor crystallinity of MnO{sub 2} nanofilms. Therefore, this facile synthetic strategy could be useful to design and synthesis of tunable nanostructures with enhanced supercapacitor behavior.

  18. Role of the antiferromagnetic pinning layer on spin wave properties in IrMn/NiFe based spin-valves

    SciTech Connect (OSTI)

    Gubbiotti, G. Tacchi, S.; Del Bianco, L.; Bonfiglioli, E.; Giovannini, L.; Spizzo, F.; Zivieri, R.; Tamisari, M.

    2015-05-07

    Brillouin light scattering (BLS) was exploited to study the spin wave properties of spin-valve (SV) type samples basically consisting of two 5?nm-thick NiFe layers (separated by a Cu spacer of 5?nm), differently biased through the interface exchange coupling with an antiferromagnetic IrMn layer. Three samples were investigated: a reference SV sample, without IrMn (reference); one sample with an IrMn underlayer (10?nm thick) coupled to the bottom NiFe film; one sample with IrMn underlayer and overlayer of different thickness (10?nm and 6?nm), coupled to the bottom and top NiFe film, respectively. The exchange coupling with the IrMn, causing the insurgence of the exchange bias effect, allowed the relative orientation of the NiFe magnetization vectors to be controlled by an external magnetic field, as assessed through hysteresis loop measurements by magneto-optic magnetometry. Thus, BLS spectra were acquired by sweeping the magnetic field so as to encompass both the parallel and antiparallel alignment of the NiFe layers. The BLS results, well reproduced by the presented theoretical model, clearly revealed the combined effects on the spin dynamic properties of the dipolar interaction between the two NiFe films and of the interface IrMn/NiFe exchange coupling.

  19. The structure of the Caenorhabditis elegans manganese superoxide dismutase MnSOD-3-azide complex

    SciTech Connect (OSTI)

    Hunter, Gary J.; Trinh, Chi H.; Bonetta, Rosalin; Stewart, Emma E.; Cabelli, Diane E.; Hunter, Therese

    2015-08-27

    C. elegans MnSOD-3 has been implicated in the longevity pathway and its mechanism of catalysis is relevant to the aging process and carcinogenesis. The structures of MnSOD-3 provide unique crystallographic evidence of a dynamic region of the tetrameric interface (residues 4154). We have determined the structure of the MnSOD-3-azide complex to 1.77- resolution. The analysis of this complex shows that the substrate analog, azide, binds end-on to the manganese center as a sixth ligand and that it ligates directly to a third and new solvent molecule also positioned within interacting distance to the His30 and Tyr34 residues of the substrate access funnel. This is the first structure of a eukaryotic MnSOD-azide complex that demonstrates the extended, uninterrupted hydrogen-bonded network that forms a proton relay incorporating three outer sphere solvent molecules, the substrate analog, the gateway residues, Gln142, and the solvent ligand. This configuration supports the formation and release of the hydrogen peroxide product in agreement with the 5-6-5 catalytic mechanism for MnSOD. The high product dissociation constant k? of MnSOD-3 reflects low product inhibition making this enzyme efficient even at high levels of superoxide.

  20. Preparation and characterization of nanostructured NiO/MnO{sub 2} composite electrode for electrochemical supercapacitors

    SciTech Connect (OSTI)

    Liu Enhui Li Wen; Li Jian; Meng Xiangyun; Ding Rui; Tan Songting

    2009-05-06

    Nanostructured nickel-manganese oxides composite was prepared by the sol-gel and the chemistry deposition combination new route. The surface morphology and structure of the composite were characterized by scanning electron microscope and X-ray diffraction. The as-synthesized NiO/MnO{sub 2} samples exhibit higher surface area of 130-190 m{sup 2} g{sup -1}. Cyclic voltammetry and galvanostatic charge/discharge measurements were applied to investigate the electrochemical performance of the composite electrodes with different ratios of NiO/MnO{sub 2}. When the mass ratio of MnO{sub 2} and NiO in composite material is 80:20, the specific capacitance value of NiO/MnO{sub 2} calculated from the cyclic voltammetry curves is 453 F g{sup -1}, for pure NiO and MnO{sub 2} are 209, 330 F g{sup -1} in 6 mol L{sup -1} KOH electrolyte and at scan rate of 10 mV s{sup -1}, respectively. The specific capacitance of NiO/MnO{sub 2} electrode is much larger than that of each pristine component. Moreover, the composite electrodes showed high power density and stable electrochemical properties.

  1. High-temperature behavior of dicesium molybdate Cs{sub 2}MoO{sub 4}: Implications for fast neutron reactors

    SciTech Connect (OSTI)

    Wallez, Gilles; Raison, Philippe E.; Smith, Anna L.; Clavier, Nicolas

    2014-07-01

    Dicesium molybdate (Cs{sub 2}MoO{sub 4})'s thermal expansion and crystal structure have been investigated herein by high temperature X ray diffraction in conjunction with Raman spectroscopy. This first crystal-chemical insight at high temperature is aimed at predicting the thermostructural and thermomechanical behavior of this oxide formed by the accumulation of Cs and Mo fission products at the periphery of nuclear fuel rods in sodium-cooled fast reactors. Within the temperature range of the fuel's rim, Cs{sub 2}MoO{sub 4} becomes hexagonal P6{sub 3}/mmc, with disordered MoO{sub 4} tetrahedra and 2D distribution of CsO bonds that makes thermal axial expansion both large (50??{sub l}?70 10{sup ?6} C{sup ?1}, 500800 C) and highly anisotropic (?{sub c}??{sub a}=6710{sup ?6} C{sup ?1}, hexagonal form). The difference with the fuel's expansion coefficient is of potential concern with respect to the cohesion of the Cs{sub 2}MoO{sub 4} surface film and the possible release of cesium radionuclides in accidental situations. - Graphical abstract: The weakness of the CsO bonds and the disordering of the MoO{sub 4} tetrahedra array in the high-temperature form are responsible for the huge thermal expansion of Cs{sub 2}MoO{sub 4} along the c-axis. - Highlights: Thermomechanical behavior of Cs{sub 2}MoO{sub 4} fission products compound is studied. High-temperature form of Cs{sub 2}MoO{sub 4} is characterized by XRD and Raman. Thermal expansion appears very high and anisotropic. Cohesion between Cs{sub 2}MoO{sub 4} and nuclear fuel seems questionable, and Cs release is expected.

  2. Role of Si on the Diffusional Interactions between U-Mo and Al-Si Alloys at 823 K (550 degrees C)

    SciTech Connect (OSTI)

    E. Perez; Y.H. Sohn; D.D. Keiser, Jr.

    2013-01-01

    U-Mo dispersions in Al-alloy matrix and monolithic fuels encased in Al-alloy are under development to fulfill the requirements for research and test reactors to use low-enriched molybdenum stabilized uranium alloys fuels. Significant interaction takes place between the U-Mo fuel and Al during manufacturing and in-reactor irradiation. The interactions products are Al-rich phases with physical and thermal characteristics that adversely affect fuel performance and lead to premature failure. Detailed analysis of the interdiffusion and microstructural development of this system was carried through diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo in contact with pure Al, Al-2wt.%Si, and Al-5wt.%Si, annealed at 823K for 1, 5 and 20 hours. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed for the analysis. Diffusion couples consisting of U-Mo vs. pure Al contained UAl3, UAl4, U6Mo4Al43, and UMo2Al20 phases. The addition of Si to the Al significantly reduced the thickness of the interdiffusion zone. The interdiffusion zones developed Al and Si enriched regions, whose locations and size depended on the Si and Mo concentrations in the terminal alloys. In the couples, the (U,Mo)(Al,Si)3 phase was observed throughout interdiffusion zone, and the U6Mo4Al43 and UMo2Al20 phases were observed only where the Si concentrations were low.

  3. Why MnIn{sub 2}O{sub 4} spinel is not a transparent conducting oxide?

    SciTech Connect (OSTI)

    Martinez-Lope, M.J.; Retuerto, M.; Calle, C. de la; Porcher, Florence

    2012-03-15

    The title compound has been synthesized by a citrate technique. The crystal structure has been investigated at room temperature from high-resolution neutron powder diffraction (NPD) data. It crystallizes in a cubic spinel structure, space group Fd3-bar m, Z=8, with a=9.0008(1) A at 295 K. It exhibits a crystallographic formula (Mn{sub 0.924(2)}In{sub 0.076(2)}){sub 8a}(In{sub 1.804(2)}Mn{sub 0.196(2)}){sub 16d}O{sub 4}, where 8a and 16d stand for the tetrahedral and octahedral sites of the spinel structure, respectively, with a slight degree of inversion, {lambda}=0.08. MnIn{sub 2}O{sub 4} shows antiferromagnetic interactions below T{sub N} Almost-Equal-To 40 K, due to the statistical distribution of Mn ions over the two available sites. Unlike the related MgIn{sub 2}O{sub 4} and CdIn{sub 2}O{sub 4} spinels, well known as transparent conducting oxides, MnIn{sub 2}O{sub 4} is not transparent and shows a poor conductivity ({sigma}=0.38 S cm{sup -1} at 1123 K): the presence of Mn ions, able to adopt mixed valence states, localizes the charges that, otherwise, would be delocalized in the spinel conduction band. - Graphical Abstract: From NPD data the crystallographic formula (Mn{sub 0.924(2)}In{sub 0.076(2)}){sub 8a}(In{sub 1.804(2)}Mn{sub 0.196(2)}){sub 16d}O{sub 4}, shows a slight degree of inversion, {lambda}=0.08 and a certain In deficiency. The presence of Mn ions, able to adopt mixed oxidation states, localize the charges that, otherwise, would be delocalized in the spinel conduction band; the presence of localized Mn{sup 2+} and Mn{sup 3+} ions provides the characteristic brown color. Highlights: Black-Right-Pointing-Pointer Accurate structural determination from NPD data: inversion degree (8%), and In deficiency. Black-Right-Pointing-Pointer Bond-valence indicates Mn{sup 2+}-Mn{sup 3+} ions; edge-sharing octahedra contain 90% In{sup 3+}+10% Mn{sup 3+} cations. Black-Right-Pointing-Pointer Conductivity several orders of magnitude lower than those of MgIn{sub 2}O{sub 4} or CdIn{sub 2}O{sub 4}. Black-Right-Pointing-Pointer Variability of Mn oxidation states cancels any electron-doping effect, emptying conduction band of mobile charge carriers. Black-Right-Pointing-Pointer Curie-Weiss behavior confirming the determined charge distribution.

  4. Development and validation of capabilities to measure thermal properties of layered monolithic U-Mo alloy plate-type fuel

    SciTech Connect (OSTI)

    Burkes, Douglas; Casella, Andrew M.; Buck, Edgar C.; Casella, Amanda J.; Edwards, Matthew K.; MacFarlan, Paul J.; Pool, Karl N.; Smith, Frances N.; Steen, Franciska H.

    2014-07-19

    The uranium-molybdenum (U-Mo) alloy in a monolithic form has been proposed as one fuel design capable of converting some of the worlds highest power research reactors from the use of high enriched uranium (HEU) to low enriched uranium (LEU). One aspect of the fuel development and qualification process is to demonstrate appropriate understanding of thermal conductivity behavior of the fuel system as a function of temperature and expected irradiation conditions. The purpose of this paper is to verify and validate the functionality of equipment methods installed in hot cells for eventual measurements on irradiated uranium-molybdenum (U-Mo) monolithic fuel specimens, procedures to operate the equipment, and models to extract the desired thermal properties. The results presented here demonstrate the adequacy of the equipment, procedures and models that have been developed for this purpose based on measurements conducted on surrogate depleted uranium-molybdenum (DU-Mo) alloy samples containing a zirconium diffusion barrier and clad in aluminum alloy 6061 (AA6061). The results are in excellent agreement with thermal property data reported in the literature for similar U-Mo alloys as a function of temperature.

  5. Concept Feasibility Report for Using Co-Extrusion to Bond Metals to Complex Shapes of U-10Mo

    SciTech Connect (OSTI)

    Lavender, Curt A.; Paxton, Dean M.; Smith, Mark T.; Soulami, Ayoub; Joshi, Vineet V.; Burkes, Douglas

    2013-12-30

    In support of the Convert Program of the U.S. Department of Energys National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative (GTRI), Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate fuel for the U.S. high-performance research reactors (USHPRR). This report documents the results of PNNLs efforts to develop the extrusion process for this concept. The approach to the development of a co-extruded complex-shaped fuel has been described and an extrusion of DU-10Mo was made. The initial findings suggest that given the extrusion forces required for processing U-10Mo, the co-extrusion process can meet the production demands of the USHPRR fuel and may be a viable production method. The development activity is in the early stages and has just begun to identify technical challenges to address details such as dimensional tolerances and shape control. New extrusion dies and roll groove profiles have been developed and will be assessed by extrusion and rolling of U-10Mo during the next fiscal year. Progress on the development and demonstration of the co-extrusion process for flat and shaped fuel is reported in this document

  6. Modification of polymer velvet cathode via metallic Mo coating for enhancement of high-current electron emission performances

    SciTech Connect (OSTI)

    Xiong, Ying; Wang, Bing; Yi, Yong; Xia, Liansheng; Zhang, Huang

    2013-09-15

    The effect of surface Mo coating on the high-current electron emission performances for polymer velvet cathode has been investigated in a diode with A-K gap of 11.5 cm by the combination of time-resolved electrical diagnostic and temporal pressure variation. Compared with uncoated polymer velvet cathode under the single-pulsed emission mode, the Mo-coated one shows lower outgassing levels (?0.40 Pa L), slower cathode plasma expansion velocity (?2.30 cm/?s), and higher emission stability as evidences by the change in cathode current, temporal pressure variation, and diode perveance. Moreover, after Mo coating, the emission consistency of the polymer velvet cathode between two adjacent pulses is significantly improved in double-pulsed emission mode with ?500 ns interval between two pulses, which further confirms the effectiveness of Mo coating for enhancement of electron emission performance of polymer velvet cathodes. These results should be of interest to the high-repetitive high-power microwave systems with cold cathodes.

  7. Thermomechanical process optimization of U-10wt% Mo Part 2: The effect of homogenization on the mechanical properties and microstructure

    SciTech Connect (OSTI)

    Joshi, Vineet V.; Nyberg, Eric A.; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas E.

    2015-07-09

    Low-enriched uranium alloyed with 10 wt% molybdenum (U-10Mo) is currently being investigated as an alternative fuel for the highly enriched uranium used in several of the United States high performance research reactors. Development of the methods to fabricate the U-10Mo fuel plates is currently underway and requires fundamental understanding of the mechanical properties at the expected processing temperatures. In the first part of this series, it was determined that the as-cast U-10Mo had a dendritic microstructure with chemical inhomogeneity and underwent eutectoid transformation during hot compression testing. In the present (second) part of the work, the as-cast samples were heat treated at several temperatures and times to homogenize the Mo content. Like the previous as-cast material, the homogenized materials were then tested under compression between 500 and 800C. The as-cast samples and those treated at 800C for 24 hours had grain sizes of 25-30 ?m, whereas those treated at 1000C for 16 hours had grain sizes around 250 ?m before testing. Upon compression testing, it was determined that the heat treatment had effects on the mechanical properties and the precipitation of the lamellar phase at sub-eutectoid temperatures.

  8. Mesoporous carbon-containing MoS{sub 2} materials formed from the in situ decomposition of tetraalkylammonium thiomolybdates

    SciTech Connect (OSTI)

    Alonso, Gabriel; Berhault, Gilles; Paraguay, Francisco; Rivera, Eric; Fuentes, Sergio; Chianelli, Russell R

    2003-05-26

    Molybdenum disulfide with unique mesoporous structure was synthesized from tetraalkylammonium thiometallate precursors in situ decomposed in a batch reactor in the presence of dibenzothiophene (DBT). The precursors used in this study were tetraalkylammonium thiomolybdates with alkyl groups ranging from propyl to octyl. Molybdenum disulfide thus prepared presents high surface area (from 255 up to 329 m{sup 2}/g), high content of carbon (C/Mo=2.7-4.0) and type IV nitrogen adsorption-desorption isotherms when decomposed from tetrahexyl-, tetraheptyl- or tetraoctylammonium thiomolybdates. The as-formed materials are poorly crystallized with a very weak intensity of the (0 0 2) peak of the 2H-MoS{sub 2} structure. Such diffraction patterns are characteristic of exfoliated samples. Characterization by TEM shows a disordered layered structure with no long range order for the MoS{sub 2} catalysts. Therefore, the nature of the alkyl group in the precursor affects both the surface area and the pore size distribution of the final MoS{sub 2} catalysts with a progressive morphological modification up to a mesoporous organization.

  9. The photocatalysis of Bi{sub 2}MoO{sub 6} under the irradiation of blue LED

    SciTech Connect (OSTI)

    Sun, Yuanyuan; Wang, Wenzhong Zhang, Ling; Sun, Songmei

    2013-10-15

    Graphical abstract: - Highlights: • ·OH trap and hole sink were involved to investigate the active radicals. • Holes play a more important role in the degradation of RhB. • The ·OH were related to the decomposition of phenol. • The ·O{sub 2}-played a leading role in the photodegradation of phenol. • Blue LED is competitive and promising alternative for the future application. - Abstract: Bi{sub 2}MoO{sub 6} has been reported as a promising photocatalyst in wastewater treatment. The active radicals generated over the Bi{sub 2}MoO{sub 6} during the photocatalytic process were thought to be hydroxyl radical (·OH) but have not been proved. Herein, Bi{sub 2}MoO{sub 6} with nanoplate like morphology was synthesized and its photocatalytic performances in the degradation of rhodamine B (RhB) and phenol as colored and colorless model pollutants respectively were evaluated under the irradiation of blue light emitting diode (LED). The tert-butyl alcohol (TBA) as a ·OH trap and ethylene diamine tetraacetic acid (EDTA) as a hole sink were involved to investigate the main active groups that are generated on Bi{sub 2}MoO{sub 6} and function during the photodegradation of RhB and phenol. In addition, it is a competitive and promising alternative plan to use blue LED as light source for the future practical application in environmental remediation.

  10. Prediction of U-Mo dispersion nuclear fuels with Al-Si alloy using artificial neural network

    SciTech Connect (OSTI)

    Susmikanti, Mike; Sulistyo, Jos

    2014-09-30

    Dispersion nuclear fuels, consisting of U-Mo particles dispersed in an Al-Si matrix, are being developed as fuel for research reactors. The equilibrium relationship for a mixture component can be expressed in the phase diagram. It is important to analyze whether a mixture component is in equilibrium phase or another phase. The purpose of this research it is needed to built the model of the phase diagram, so the mixture component is in the stable or melting condition. Artificial neural network (ANN) is a modeling tool for processes involving multivariable non-linear relationships. The objective of the present work is to develop code based on artificial neural network models of system equilibrium relationship of U-Mo in Al-Si matrix. This model can be used for prediction of type of resulting mixture, and whether the point is on the equilibrium phase or in another phase region. The equilibrium model data for prediction and modeling generated from experimentally data. The artificial neural network with resilient backpropagation method was chosen to predict the dispersion of nuclear fuels U-Mo in Al-Si matrix. This developed code was built with some function in MATLAB. For simulations using ANN, the Levenberg-Marquardt method was also used for optimization. The artificial neural network is able to predict the equilibrium phase or in the phase region. The develop code based on artificial neural network models was built, for analyze equilibrium relationship of U-Mo in Al-Si matrix.

  11. Heat treated 9 Cr-1 Mo steel material for high temperature application

    DOE Patents [OSTI]

    Jablonski, Paul D.; Alman, David; Dogan, Omer; Holcomb, Gordon; Cowen, Christopher

    2012-08-21

    The invention relates to a composition and heat treatment for a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650.degree. C. The novel combination of composition and heat treatment produces a heat treated material containing both large primary titanium carbides and small secondary titanium carbides. The primary titanium carbides contribute to creep strength while the secondary titanium carbides act to maintain a higher level of chromium in the finished steel for increased oxidation resistance, and strengthen the steel by impeding the movement of dislocations through the crystal structure. The heat treated material provides improved performance at comparable cost to commonly used high-temperature steels such as ASTM P91 and ASTM P92, and requires heat treatment consisting solely of austenization, rapid cooling, tempering, and final cooling, avoiding the need for any hot-working in the austenite temperature range.

  12. H-point exciton transitions in bulk MoS{sub 2}

    SciTech Connect (OSTI)

    Saigal, Nihit; Ghosh, Sandip

    2015-05-04

    Reflectance and photoreflectance spectrum of bulk MoS{sub 2} around its direct bandgap energy have been measured at 12?K. Apart from spectral features due to the A and B ground state exciton transitions at the K-point of the Brillouin zone, one observes additional features at nearby energies. Through lineshape analysis the character of two prominent additional features are shown to be quite different from that of A and B. By comparing with reported electronic band structure calculations, these two additional features are identified as ground state exciton transitions at the H-point of the Brillouin zone involving two spin-orbit split valance bands. The excitonic energy gap at the H-point is 1.965?eV with a valance bands splitting of 185?meV. While at the K-point, the corresponding values are 1.920?eV and 205?meV, respectively.

  13. Process for fabricating high reflectance-low stress Mo--Si multilayer reflective coatings

    DOE Patents [OSTI]

    Montcalm, Claude; Mirkarimi, Paul B.

    2001-01-01

    A high reflectance-low stress Mo--Si multilayer reflective coating particularly useful for the extreme ultraviolet (EUV) wavelength region. While the multilayer reflective coating has particular application for EUV lithography, it has numerous other applications where high reflectance and low stress multilayer coatings are utilized. Multilayer coatings having high near-normal incidence reflectance (R.gtoreq.65%) and low residual stress (.ltoreq.100 MPa) have been produced using thermal and non-thermal approaches. The thermal approach involves heating the multilayer coating to a given temperature for a given time after deposition in order to induce structural changes in the multilayer coating that will have an overall "relaxation" effect without reducing the reflectance significantly.

  14. High reflectance-low stress Mo-Si multilayer reflective coatings

    DOE Patents [OSTI]

    Montcalm, Claude; Mirkarimi, Paul B.

    2000-01-01

    A high reflectance-low stress Mo-Si multilayer reflective coating particularly useful for the extreme ultraviolet (EUV) wavelength region. While the multilayer reflective coating has particular application for EUV lithography, it has numerous other applications where high reflectance and low stress multilayer coatings are utilized. Multilayer coatings having high near-normal incidence reflectance (R.gtoreq.65%) and low residual stress (.ltoreq.100 MPa) have been produced using thermal and non-thermal approaches. The thermal approach involves heating the multilayer coating to a given temperature for a given time after deposition in order to induce structural changes in the multilayer coating that will have an overall "relaxation" effect without reducing the reflectance significantly.

  15. Microstructural Characterization of Irradiated U-7Mo/Al-5Si Dispersion to High Fission Density

    SciTech Connect (OSTI)

    J. Gan; B. D. Miller; D. D. Keiser, Jr.; A. B. Robinson; J. W. Madden; P. G. Medvedev; D. M. Wachs

    2014-11-01

    The fuel development program for research and test reactors calls for improved knowledge on the effect of microstructure on fuel performance in reactors. This work summarizes the recent TEM microstructural characterization of an irradiated U-7Mo/Al-5Si dispersion fuel plate (R3R050) irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory to 5.21021 fissions/cm3. While a large fraction of the fuel grains is decorated with large bubbles, there is no evidence showing interlinking of these large bubbles at the specified fission density. The attachment of solid fission product precipitates to the bubbles is likely the result of fission product diffusion into these bubbles. The process of fission gas bubble superlattice collapse appears through bubble coalescence. The results are compared with the previous TEM work of the dispersion fuels irradiated to lower fission density from the same fuel plate.

  16. Thermodynamic modeling and experimental validation of the Fe-Al-Ni-Cr-Mo alloy system

    SciTech Connect (OSTI)

    Teng, Zhenke; Zhang, F; Miller, Michael K; Liu, Chain T; Huang, Shenyan; Chou, Y.T.; Tien, R; Chang, Y A; Liaw, Peter K

    2012-01-01

    NiAl-type precipitate-strengthened ferritic steels have been known as potential materials for the steam turbine applications. In this study, thermodynamic descriptions of the B2-NiAl type nano-scaled precipitates and body-centered-cubic (BCC) Fe matrix phase for four alloys based on the Fe-Al-Ni-Cr-Mo system were developed as a function of the alloy composition at the aging temperature. The calculated phase structure, composition, and volume fraction were validated by the experimental investigations using synchrotron X-ray diffraction and atom probe tomography. With the ability to accurately predict the key microstructural features related to the mechanical properties in a given alloy system, the established thermodynamic model in the current study may significantly accelerate the alloy design process of the NiAl-strengthened ferritic steels.

  17. Intense femtosecond photoexcitation of bulk and monolayer MoS{sub 2}

    SciTech Connect (OSTI)

    Paradisanos, I.; Fotakis, C.; Kymakis, E.; Kioseoglou, G.; Stratakis, E.

    2014-07-28

    The effect of femtosecond laser irradiation on bulk and single-layer MoS{sub 2} on silicon oxide is studied. Optical, field emission scanning electron microscopy and Raman microscopy were used to quantify the damage. The intensity of A{sub 1g} and E{sub 2g}{sup 1} vibrational modes was recorded as a function of the number of irradiation pulses. The observed behavior was attributed to laser-induced bond breaking and subsequent atoms removal due to electronic excitations. The single-pulse optical damage threshold was determined for the monolayer and bulk under 800?nm and 1030?nm pulsed laser irradiation, and the role of two-photon versus one photon absorption effects is discussed.

  18. Extreme ultraviolet spectra of highly ionized Ge, Kr and Mo emitted by imploding plasmas

    SciTech Connect (OSTI)

    Goldsmith, S.; Feldman, U.; Cohen, L.; Behring, W.E.

    1984-01-01

    Spectra of highly ionized Ge, Kr and Mo in the spectral region of 10 to 80A were excited in laser-produced plasmas. The plasma was obtained by focusing the energy of the 24 laser beams of the University of Rochester Omega system on 0.4 mm diameter microballoon targets. The laser pulse duration was in the range of 0.87 to 1.09 ns, with total energy in the range of 1.8 to 2.2 kJ. The observed spectral lines include n = 2-2 transitions in the oxygen and fluorine isoelectronic sequences and n = 3 to 4 transitions in the sodium, magnesium and aluminum isoelectronic sequences. The present observations are compared with previous experimental and theoretical studies.

  19. Insulator to correlated metal transition in V_1-xMo_xO_2

    SciTech Connect (OSTI)

    Klimczuk, Tomasz; Ronning, Filip; Holman, Katherine; Mcqueen, Tyrel M; Williams, Anthony J; Stephens, P W; Zandbergen, Henny W; Xu, Q; Cava, Robert J

    2009-01-01

    The change from metallic to insulating states is one of the most dramatic transitions that solids undergo on cooling or chemical doping. Many materials display this transition, but only a handful have the right combination of crystal structure and physical properties to serve as model systems. VO{sub 2} is one of those materials. Using Mo as a chemical dopant in VO{sub 2}, we find unanticipated phenomenology for both the electronic and structural characteristics of the resulting insulator to metal transition. The results support a complex, previously proposed scenario involving the coexistence of both electron repulsion and electron pairing for yielding an insulator in VO{sub 2}, but not simply; many issues are raised about local versus itinerant behavior and structure-property correlations in this most iconic ofdoped correlated electron systems.

  20. Microstructural characterization of as-cast biocompatible Co-Cr-Mo alloys

    SciTech Connect (OSTI)

    Giacchi, J.V.; Morando, C.N.; Fornaro, O.; Palacio, H.A.

    2011-01-15

    The microstructure of a cobalt-base alloy (Co-Cr-Mo) obtained by the investment casting process was studied. This alloy complies with the ASTM F75 standard and is widely used in the manufacturing of orthopedic implants because of its high strength, good corrosion resistance and excellent biocompatibility properties. This work focuses on the resulting microstructures arising from samples poured under industrial environment conditions, of three different Co-Cr-Mo alloys. For this purpose, we used: 1) an alloy built up from commercial purity constituents, 2) a remelted alloy and 3) a certified alloy for comparison. The characterization of the samples was achieved by using optical microscopy (OM) with a colorant etchant to identify the present phases and scanning electron microscopy (SE-SEM) and energy dispersion spectrometry (EDS) techniques for a better identification. In general the as-cast microstructure is a Co-fcc dendritic matrix with the presence of a secondary phase, such as the M{sub 23}C{sub 6} carbides precipitated at grain boundaries and interdendritic zones. These precipitates are the main strengthening mechanism in this type of alloys. Other minority phases were also reported and their presence could be linked to the cooling rate and the manufacturing process variables and environment. - Research Highlights: {yields}The solidification microstructure of an ASTM-F75 type alloy were studied. {yields}The alloys were poured under an industrial environment. {yields}Carbides and sigma phase identified by color metallography and scanning microscopy (SEM and EDS). {yields}Two carbide morphologies were detected 'blocky type' and 'pearlite type'. {yields}Minority phases were also detected.